Дисертації з теми "Water - Purification - Filtration"
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1
Jeffcoat, Stuart Blakely. "The importance of hydrophobicity/hydrophilicity on particle removal in deep bed filtration and macroscopic filtration modeling." Diss., Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/20149.
2
Djembarmanah, Rachmawati Sugihhartati. "Activated unsaturated sand filter as an alternative technology to remove copper, manganese, zinc and nickel from waters." Thesis, Swansea University, 2012. https://cronfa.swan.ac.uk/Record/cronfa42435.
Анотація:
An activated unsaturated sand filter (AUSF) is one of only a few of the filtration technologies utilized to treat waters and wastewaters that use unsaturated filter media. AUSF employs sand coated with potassium permanganate and operates with an open chamber allowing free air flow into the column of sand. The AUSF also benefits from operation without the need for a sedimentation unit. Previous studies have demonstrated the efficient removal of iron and manganese using an AUSF, however, to date there are still very limited studies available that use AUSF technology for the removal of metals from waters and wastewaters. Thus, there is an urgent need and opportunity to exploit this technology further. This research was conducted in order to develop and study the characteristics and subsequent operational performance of a novel AUSF media. The study focuses on the removal of copper, manganese, zinc and nickel from a synthetic wastewater and extends current knowledge to a passive aeration process rather than the active aeration used in the previous study by Lee et. al. (2004). The characterisation involved the use of sieving, Brunauer- Fmmett-Teller (BET) analysis, water evaporation studies and scanning electron microscopy (SEM) for structural analysis such as particle size, surface area, porosity and topography. Energy dispersive X-ray analysis (EDX), acid/alkali resistance, isoelectric point determination and acid digestion analysis were used to determine the chemical constituency, chemical stability, electrical charge properties and the binding efficiency of the media. Finally, tracer studies were employed to determine the flow characteristics through the particle media. The manganese coated sand was proven effective for the removal of copper in both agitated tank batch studies and continuous column studies. The batch studies showed that the equilibrium sorption of copper followed a Langmuir isotherm and the sorption rate was best modelled using the pseudo-second-order kinetic model. This suggests that adsorption is taking place as a single homogeneous layer on the surface of the sand particle via the chemisorption method. The Weber-Morris and Bangham models were used to determine the rate-controlling mechanism and this was found to be predominantly intra-particle diffusion. This was confirmed for column studies using the Bohart-Adams model that demonstrated that liquid-film mass transfer was not significant. Several mechanisms of metal removal are proposed and these include precipitation, electrostatic attraction, adsorption, ion exchange and complex ion formation. The column studies demonstrated that dispersion was low under the operating conditions and plug flow performance could be inferred, thus justifying the use of the AUSF model employed. Copper was best removed when operating as an unsaturated particle bed and the removal capacity was increased by approximately 100% when compared to a saturated particle bed. Moreover, the pH increase that occurs on exposure of the process water to the unsaturated column further improves removal capacity. Thus, there is no requirement for an expensive pH adjustment as a pre-treatment process prior to this unit operation. In addition, the removal capacity of the AUSF was demonstrated to increase with lower metal concentrations, lower water flow rates, smaller sand particles, an increase in manganese to sand ratio and an increase in particle bed height. The AUSF performance in removing metals followed the order Cu > Mn > Zn > Ni for individual and mixed component solutions and Cu > Ni > Zn > Mn for a synthetic wastewater typical of the electroplating industries. In conclusion, the novel manganese coated AUSF developed is effective in the removal of metals from solution and offers the potential of a sustainable low cost treatment method for the purification of waters and wastewaters.
3
Ahmad, Rasheed. "Filtration and backwashing performance of biologically-active filters." Diss., Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/21659.
4
Pardon, Ojeda Mauricio. "Treatment of turbid surface water for small community supplies." Thesis, University of Surrey, 1989. http://epubs.surrey.ac.uk/2191/.
5
Richman, Marjorie Timmerly. "Particle and biomass detachment during biological filter backwashing : impact of water chemistry and backwash method." Diss., Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/19519.
6
Augustine, Robyn. "Forward osmosis membranes for direct fertigation within the South African wine industry." Thesis, Cape Peninsula University of Technology, 2017. http://hdl.handle.net/20.500.11838/2664.
Анотація:
Thesis (MTech (Chemical Engineering))--Cape Peninsula University of Technology, 2017.Water scarcity in South Africa (SA) and more specifically Cape Town, Western Cape, has escalated to disaster levels in 2018. Agriculture and irrigation account for 62% of SA’s accessible potable water (Thopil & Pouris, 2016), and although the agriculture sector plays a pivotal role in SA’s socio-economic development, the future of the sector is dependent on critical issues such as climate variability and population growth (Besada & Werner, 2015). Wine production in SA is an important agricultural activity, contributing great economic value to the agri-food sector. However, despite this, the wine industry is responsible for vast water consumption and the unsafe disposal of winery wastewater, which are critical issues from an environmental and economic standpoint. The ever-imminent crisis pertaining to the limited supply of fresh water from conventional water resources has necessitated the need to develop alternative water resources to supplement an increased water supply, which include the reuse of wastewater, ground water, brackish water (BW) and seawater (SW) desalination. When fresh water supplies are limited, agricultural irrigation is penalised. The reuse of agricultural wastewater as a substitution for potable water irrigation may prove beneficial in areas where water shortages are severe. Forward osmosis (FO) is a developing desalination technology that has received increased attention as a promising lower-energy desalination technology. FO technology relies on the natural osmotic process, driven by a concentration gradient as opposed to significant hydraulic pressures like reverse osmosis (RO). Water is extracted from a lower concentrated feed solution (FS) to a highly concentrated draw solution (DS). The term “lower energy” is only applicable for applications where the recovery of the DS is not required. FO technology offers several advantages. However, the lack of suitable membrane modules and DSs hinder its practical application. FO offers novelty applications in which specialised DSs are selected to serve as the final product water, most notably concentrated fertilisers for direct fertigation. The aim of this study was to evaluate the performance and compatibility of commercially available cellulose triacetate (CTA) and aquaporin biomimetic FO membranes with commonly used fertilisers for direct fertigation within the SA wine industry, using a fertiliser drawn forward osmosis (FDFO) system.
7
Johnson, Sissy Daniel. "Concentrations [sic] levels of fluoride in bottled drinking water and filtered water using home filtration systems." Morgantown, W. Va. : [West Virginia University Libraries], 2000. http://etd.wvu.edu/templates/showETD.cfm?recnum=1439.
Анотація:
Thesis (M.S.)--West Virginia University, 2000.Title from document title page. Document formatted into pages; contains vi, 47 p. : ill. (some col.) Vita. Includes abstract. Includes bibliographical references (p. 44-46).
8
Amburgey, James E. "Improving filtration for removal of cryptosporidium oocysts and particles from drinking water." Diss., Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/20723.
9
Raveendran, Palanivel. "Mechanisms of particle detachment during filter backwashing." Diss., Georgia Institute of Technology, 1993. http://hdl.handle.net/1853/18989.
10
Isaeva, Margarita, and Castro Natasha Montes. "Water Treatment for the Removal of Iron and Manganese." Thesis, Högskolan i Skövde, Institutionen för teknik och samhälle, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-5357.
Анотація:
The purpose of the study is to find a suitable method for removal of iron and manganese considering local economic and environmental aspects. El Salvador is situated in Central America with a coast line towards the Pacific Ocean. The country borders Guatemala and Honduras. Aguilares is a town situated in the department of San Salvador, with a population of approximately 33,000 people. Currently, the population is provided with water for about two hours per day, since it is the highest capacity of the existing wells. During these two hours many households fill a small tank with water to use for the remainder of the day. The water is not safe to use for oral consumption because of the levels of bacteria and other contamination. One of the wells, situated in the community of Florída is not in use at this date because of the high levels of Iron and Manganese in the ground water which cannot be removed with the present technique.Ground water is naturally pure from bacteria at a depth of 30 m or more, however solved metals may occur and if the levels are too high the water is unsuitable to drink. The recommended maximum levels by WHO (2008) [1] for Iron and Manganese are 2 mg/l and 0.5 mg/l respectively.Literature and field studies led to the following results; Iron and manganese can be removed by precipitation followed by separation. Precipitation is achieved by aeration, oxygenation or chemical oxidation and separation is achieved by filtration or sedimentation.The different methods all have advantages and disadvantages. However the conclusion reached in this report is that aeration and filtration should be used in the case of Florída. What equipment and construction that should be used depends on economic and resource factors as well as water requirements, which is up to the council of Aguilares to deliberate.
11
Bailey, Andrew Douglas. "An exploratory investigation of crossflow microfiltration for solid/liquid separation in biological wastewater treatment." Master's thesis, University of Cape Town, 1989. http://hdl.handle.net/11427/21915.
Анотація:
This thesis contains the results and discussion of an exploratory investigation into the application of Crossflow Microfiltration (CFMF) for solid/liquid separation in biological wastewater treatment systems. The principal objective of the study was to assess the influence of CFMF on the performance of identified biological wastewater treatment systems. It was not the objective to optimise filtration performance. A literature review indicated that the crossflow mode of filtration has been widely accepted as a unit operation in the fermentation industry. The filtration mode is now being applied not only for solid/liquid separation but also for separations on a molecular and ionic level. Very few applications of crossflow filtration in the context of biological wastewater treatment solid/liquid separation are reported in the literature. The reasons for this limited experience would appear to be the scale involved and the perceived high costs; separations in the fermentation industry are usually conducted at relatively small scale (laboratory or pilot-scale) and involve high-value products, justifying high capital and operating costs. Also, the high level of separation performance attained is perhaps not necessary for many wastewater treatment applications. No doubt these reservations are largely valid. However, these arguments cannot be applied equally to all filtration methods and wastewater treatment schemes. For example, the costs of microfiltration are substantially less than ultrafiltration or reverse osmosis, and in certain cases effluents with extremely low suspended solids contents may be required. In the light of these observations an investigation of CFMF for solid/liquid separation in biological wastewater treatment systems appears justified. Two biological treatment systems were selected for study: the Upflow Anaerobic Sludge Bed (UASB) reactor and the Activated Sludge system. The envisaged benefits accruing from the application of CFMF were different in each case.
12
Palmer, Carolyn C. "Manganese removal by oxidation and mixed-media filtration." Thesis, Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/91051.
Анотація:
Manganese is typically found in all water supplies in the United States. Manganese concentrations are usually higher in water obtained from groundwater sources or resei:voir hypolinutlons. This is because manganese is more soluble in the reducing conditions normally found in these waters. Although manganese is not known to cause any health related problems, the secondary drinking water MCL for manganese is 0.05 mg/L. This standard was set to eliminate aesthetic problems associated with manganese bearing waters.
In this study continuous-flow filters were operated in both pre-oxidative (oxidized Mn applied to filters) and auto-oxidative (soluble Mn applied) modes. The oxidants used were dllorine (HOCl/OCl⁻) , potassium permanganate (KMnO₄), chlorine dioxide (ClO₂), and ozone (O₃). Other experimental parameters included: filter media type - manganese coated or non-coated, filter loading rate --2 to 5 gpm/f², operating pH -- pH 6 to pH 9, and temperature --5 to 25℃.
The most important experimental parameter was whether or not the filter media had a prior oxidized coating of manganese. If this was the case the filter produced an effluent concentration of manganese below the MCL under all pre-oxidative conditions and under auto-oxidative conditions when the pH was above neutral.
Increased flow rate through the filter caused deeper penetration of manganese into the filter bed. This should not prove to cause an effluent breakthrough problem for filter depths typically used in water treatment plants. Temperature and pH effected the reaction rate of manganese oxidation in both the pre- and auto-oxidative modes. In most cases th.is did not effect the effluent quality from manganese coated filter media. However, when non-coated media was used and no oxidant was added, a decrease in pH or temperature usually adversely effected effluent quality.M.S.
13
Chaturvedula, Durgaprasad. "Treatment of Mililani I Well Water By "Nanofiltration"." Thesis, Water Resources Research Center, University of Hawaii at Manoa, 1995. http://hdl.handle.net/10125/21918.
Анотація:
Two nanofiltration membranes, a thin film composite (TFC) membrane, a cellulose triacetate (CTA) membrane, were tested as pretreatment alternatives to extend the effective life of GAC at Mililani Wells I, Oahu, Hawaii. TFC membranes achieved excellent 1,2,3-trichloropropane (TCP), and 1,2-dibromo-3-chloropropane (DBCP) removal percentages whereas CTA membranes performed very poorly. TFC membranes showed promising signs of reducing total organic carbong (TOC) from the nanofiltration unit influent. In Mililani waters, only TCP is present in large amounts. It is suggested that further studies should be conducted where there is a chance of observing membrane's performance against high quantities of 1,2-dibromoethane (EDB), and DBCP. Due to the lack of trained personnel, not many TOC analyses were conducted. It is proven that nanofiltration is a viable treatment alternative and a pilot scale study should be conducted in the future taking economics also into consideration.Thesis (M. S.)--University of Hawaii at Manoa, 1995.
Includes bibliographical references (leaves 46-48).
UHM: Has both book and microform.
Water Resources Research Center
14
Law, Ming-chu Cecilia, and 羅明珠. "The combined fouling of nanofiltration membranes by particulate solidsand dissolved organics in wastewater treatment and reuse." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B43703689.
15
Marda, Saurabh. "Effect of Ozonation and BAC Filtration Processes on Monochloramine Demand." Thesis, Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/10577.
Анотація:
Although the kinetics and mechanism of monochloramine decay in organic-free waters are relatively well understood, those in natural waters are not, due to exceedingly complex and poorly defined interactions of monochloramine with natural organic matter (NOM) and particles. Ozonation followed by a biologically activated carbon (BAC) filtration is a commonly practiced process option that affects the characteristics of both dissolved and particulate constituents in the water. However, how these changes in water constituents affect stability of the residual disinfectant, or monochloramine in particular, are currently unknown. Kinetics of monochloramine decay in water samples obtained before and after ozonation and BAC treatments were performed under varying operating conditions were determined by bench-scale batch experiments. Stability of monochloramine in the BAC filter effluent samples obtained at different times after backwashing was determined. It was found that in most cases monochloramine stability was greatly decreased after BAC filtration. Further filtering the BAC effluents with 1.2 and #61549;m polycarbonate membrane resulted in a substantial increase in monochloramine stability. A further increase was observed after filtering the samples using a 0.4 m membrane. This finding suggested that particulate matter generated from the filters could be the major cause of monochloramine instability. The fines from the activated carbon, possible components of the particulate matter eluting from the BAC filters, were found to exert an insignificant monochloramine demand both in the presence and absence of NOM, which is contrary to previous speculation in the literature about their demand for monochloramine. While there appears to exist a relationship between chloramine demand and HPC count of the filter effluent, more research will be needed to determine the effect of nature and type of microorganisms and their byproducts have on chloramine demand. Effect of ozonation on monochloramine stability is also under investigation using both the water sampled from full-scale plant and the synthetic water prepared with Suwannee River NOM.
16
Coffey, Bradley Martin. "Removal of soluble iron and manganese from groundwater by chemical oxidation and oxide-coated multi-media filtration." Thesis, Virginia Tech, 1990. http://hdl.handle.net/10919/42068.
17
Occiano, Suzanne. "The mechanism for free chlorine oxidation of reduced manganese in mixed-media filters." Thesis, Virginia Tech, 1988. http://hdl.handle.net/10919/44082.
Анотація:
The removal mechanisms of soluble manganese [Mn (1l)] through mixed-media filters were investigated. Experimentation was directed toward the continuous supply of an oxidant during column filter studies. Free chlorine (HOCl, OC1â ) was chosen to increase soluble manganese removal efficiency because chlorine is readily available and inexpensive.
Filter media from four different water treatment plants were used in this study. Continuous-flow filter columns were operated in the presence and absence of 2.0 milligrams per Liter (mg/ L) free chlorine. Maintaining constant influent manganese concentrations of 1.0 mg/L and flow rates of 2.5 gallons per minute per foot squared (gpm/ft2), the operational pH values of 6-6.2, 7.8 and 8.8 were investigated.
Results indicate that a continuous feed of free chlorine (2 mg/L) applied to the filter columns could increase manganese (II) removal efficiency. However, the amount and oxidation state of the MnOx(S) surface coating initially on the media and the influent pH had major influences upon the uptake of soluble manganese. From numerous Mn (II) uptake studies with different media and varying pH conditions, oxide-coated filter media continuously regenerated with free chlorine could result in increased soluble manganese removal through adsorption upon the MnOx(s) surface coating and subsequent oxidation directly on the media surface. The relationships of manganese removal and chlorine consumed were also explored.
To further investigate the mechanisms of free chlorine oxidation for the removal of reduced manganese, pH 5.0 backtitrations were conducted following exhaustion of the filter media. The exposure of such low pll conditions to columns operated in the presence and absence of HOCI would ascertain if oxidation of the adsorbed Mn2+ was always occurring, regardless of an oxidant feed. Results indicated that in the absence of HOCI, the mechanisms for manganese removal on oxide-coated filter media were adsorption only. With the additional of HOCI, the adsorbed Mn2+ is oxidized directly on the surface of the media, thereby, continuously regenerating the surface oxide coating.
Additional work was begun to ascertain if free chlorine could be used as a viable alternative to potassium permanganate (KMnO4) regeneration of oxide-coated filter media. Preliminary findings indicate from column cycling experiments that free chlorine could be used to regenerate oxide-coated filter media prior to backwashing.Master of Science
18
Miller, Stanley David 1960. "Mass separation techniques for the design of fixed film bioreactors." Thesis, The University of Arizona, 1988. http://hdl.handle.net/10150/276846.
Анотація:
Dissolved organics in wastewater samples were separated into three size fractions (0-1,000 amu, 1,000-10,000 amu, and 10,000 amu-0.22 m) using ultrafiltration (UF) membranes. The mass distribution within each fraction was adjusted by using a new permeation coefficient model to account for membrane rejection. Dissolved organic and soluble BOD (sBOD) removals in a trickling filter were studied for the different size fractions. The Logan trickling filter model was recalibrated and used to generate predicted removals by size fraction of sBOD, dissolved organic carbon (DOC), and biodegradable DOC (bDOC) for a given influent. Although there was moderate agreement between observed and predicted removals, more investigation is needed to explain shifts in material between different size fractions. Of the three parameters, bDOC may offer a better parameter for modelling trickling filter performance than sBOD.
19
Nsengiyumva, Dominique. "Field evaluation of three systems for filtering polluted river water for use in subsurface irrigation." Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=28868.
Анотація:
Three systems for filtering polluted river water for use in subsurface irrigation have been designed, operated and evaluated. One system consisted of filtering the water through filter basins covered with grass. The second system used geotextiles in filter basins. The third system consisted of flooding a section of a field. In this system, the water was filtered as it moved through the soil towards the subsurface drainage/irrigation drain pipes.It was found that grass filter basins are very efficient in removing sediment from river water. Grass filter basins having drain pipes placed in trenches 30 cm wide backfilled with sand gave the best results. More than 90% of sediments were removed from the river water. From the outflow measurements, it was found that less than 0.2% of the field to be irrigated needs to be devoted to the filtration system.
Important filter design parameters, namely filtration rates per unit area of filter basin and per unit length of filter trench and drain pipe, were determined.
Due to the fast clogging of the geotextile, filtration of river water through basins covered with geotextile was found to be impractical and expensive, as compared to filtration using water tolerant grasses as a basin cover.
Flooding a section of the crop land combined with controlled drainage was found to be an efficient way of irrigating maize crop. The yields obtained with this system were comparable with those obtained with conventional subsurface irrigation. Flood irrigation combined with controlled drainage would be particularly commendable on relatively flat fields which have subsurface drains.
20
Kasongo, Wa Kasongo Godwill. "Enhancement of membrane surface characteristics to improve membrane performance and durability in the treatment of municipal MBR effluent." Thesis, Cape Peninsula University of Technology, 2018. http://hdl.handle.net/20.500.11838/2695.
Анотація:
Thesis (Master of Engineering in Chemical Engineering))--Cape Peninsula University of Technology, 2018.Fresh, clean water has always been critical for the world's social development. Supply of water can be reinforced through recycling and reuse; and secondary treatment of municipal wastewater effluent with a membrane bioreactor (MBR) followed by a reverse osmosis (RO) process, has emerged as a crucial treatment process for water reuse. However, fouling of RO membranes in such process is unavoidable. This leads to poor performance, increase in operational cost and degradation of the membrane material, which reduces the membrane life span. Various researches have been conducted to provide an understanding of the mechanism of fouling, and methods have been developed to minimize it. In this research, the effect of surface modification to minimise fouling on a thin film composite polyamide RO membrane was investigated. This study was divided into three parts, namely: membrane modification, biofouling and filtration using RO. Two modifying agents, PVA and DMAEMA, were used as grafting solutions. Escherichia coli (E. coli) were used as the biofoulant to study the ant-biofouling properties of the membranes. A make-up synthetic MBR secondary effluent feed was used in a bench scale RO process. During the membrane modification process, the membrane was treated using two different approaches. Firstly, the covalent attachment of polyvinyl alcohol (PVA) through Glutaraldehyde (GA) onto the surface and secondly the redox initiated grafting of dimethyl amino ethyl methacrylate (DMAEMA PVA and DMAEMA grafting solutions were applied at four different concentrations). The PVA and DMAEMA modifying agents were successfully grafted onto the membrane top layers and were confirmed by the functional groups, present, using the Attenuated Total Reflectance–Fourier Transform Infrared spectroscopy (ATR-FTIR) spectra. The morphology of the membrane surfaces was investigated using Scanning Electron Microscopy (SEM), before and after treatment. SEM analysis showed better membrane structures with PVA grafting compared to DMAEMA.
21
Westensee, Dirk Karl. "Post-treatment technologies for integrated algal pond systems." Thesis, Rhodes University, 2015. http://hdl.handle.net/10962/d1018180.
Анотація:
Integrated Algae Pond Systems (IAPS) are a derivation of the Oswald designed Algal Integrated Wastewater Pond Systems (AIWPS®) and combine the use of anaerobic and aerobic bioprocesses to effect wastewater treatment. IAPS technology was introduced to South Africa in 1996 and a pilot plant designed and commissioned at the Belmont Valley WWTW in Grahamstown. The system has been in continual use since implementation and affords a secondarily treated water for reclamation according to its design specifications which most closely resemble those of the AIWPS® Advanced Secondary Process developed by Oswald. As a consequence, and as might be expected, while the technology performed well and delivered a final effluent superior to most pond systems deployed in South Africa it was unable to meet The Department of Water Affairs General Standard for nutrient removal and effluent discharge. The work described in this thesis involved the design, construction, and evaluation of several tertiary treatment units (TTU') for incorporation into the IAPS process design. Included were; Maturation Ponds (MP), Slow Sand Filter (SSF) and Rock Filters (RF). Three MP's were constructed in series with a 12 day retention time and operated in parallel with a two-layered SSF and a three-stage RF. Water quality of the effluent emerging from each of these TTU's was monitored over a 10 month period. Significant decreases in the chemical oxygen demand (COD), ammonium-N, phosphate-P, nitrate-N, faecal coliforms (FC) and total coliforms (TC) were achieved by these TTU's. On average, throughout the testing period, water quality was within the statutory limit for discharge to a water course that is not a listed water course, with the exception of the total suspended solids (TSS). The RF was determined as the most suitable TTU for commercial use due to production of a better quality water, smaller footprint, lower construction costs and less maintenance required. From the results of this investigation it is concluded that commercial deployment of IAPS for the treatment of municipal sewage requires the inclusion of a suitable TTU. Furthermore, and based on the findings presented, RF appears most appropriate to ensure that quality of the final effluent meets the standard for discharge.
22
Unlu, Meltem. "Indigo Dyeing Wastewater Treatment By The Membrane Based Filtration Process." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/12609464/index.pdf.
Анотація:
In the present study, the recovery of the indigo dyeing rinsing wastewater originating from a denim textile mill to the degree of reuse quality, which generally requires nanofiltration (NF), was investigated. In order to control flux decline and hence to maintain an efficient NFcoagulation, microfiltration (MF) and sequential MF plus ultrafiltration (UF) pretreatment process alternatives were tested. All pretreatment alternatives were optimized to reduce chemical oxygen demand (COD) and color load to NF. Coagulation process was investigated using the coagulants, aluminum sulfate (Al2(SO4)3.18H2O) and ferric chloride (FeCl3.6H2O) by running a series of jar tests. The results showed that coagulation process did not provide an effective and efficient pretreatment due to high dose of coagulant requirement. MF tests run by using 0.45, 2.5 and, 8 µ
m membranes indicated that MF through 0.45 µ
m pore-sized membrane is the best process providing 64% color and 29% COD removals, leading to a color value of 2493 Pt-Co and COD of 892 mg /L in the permeate. Application of sequential MF+UF filtration provided a significant benefit over single MF in terms of rejections and also permeate flux. UF applied after MF provided additional 62% color and 4% COD removals leading to 960 Pt-Co color and 856 mg/L COD. NF tests conducted using pretreated wastewater via single MF and sequential MF+UF indicated that single MF is the best pretreatment to NF and this treatment scheme provided 99% color, 97% COD and 80 % conductivity removals and satisfied reuse criteria.
23
Lambrechts, Rhynhardt. "A performance and energy evaluation of a fertiliser-drawn forward osmosis (FDFO) system." Thesis, Cape Peninsula University of Technology, 2018. http://hdl.handle.net/20.500.11838/2747.
Анотація:
Thesis (Master of Engineering in Chemical Engineering)--Cape Peninsula University of Technology, 2018.Globally, water is considered an essential resource as it sustains human, animal and plant life. Water is not only essential for all forms of life but imperative for economic growth. The world’s population is increasing at a disquieting rate, which will result in an increased demand for fresh water and food security. The agricultural industry is the main consumer of global freshwater and utilises fertilisers in order to meet food demands. The demand for water in South Africa (SA) has increased considerably due to the rapid expansion of the agricultural industry, and of the municipal and industrial sectors. Agricultural developments in SA are affected greatly as the country is facing a current drought crisis as a result of low rainfall and large water demands. With an abundance of saline water globally, desalinisation will be a major contributor to solving the global freshwater crisis. With limited fresh water resources accompanied by the agricultural industry as a major consumer, alternative measures are required to desalinate water specifically for agricultural use. Forward osmosis (FO) is a membrane technology that gained interest over the past decade because it has several advantages over pressure-driven membrane processes such as reverse osmosis (RO). FO technology is based on the natural osmotic process which is driven by a concentration gradient between two solutions separated by a semi-permeable membrane. Naturally, water will permeate through the membrane from a solution of low solute concentration or low osmotic pressure (OP) known as a feed solution (FS) to a solution of a higher concentration or higher OP also known as a draw solution (DS). Whilst various research studies have contributed to several advances in FO, several process limitations such as reverse solute flux (RSF), concentration polarisation (CP) and membrane fouling remain problematic, hindering FO for large-scale applications. Further investigation is therefore warranted and crucial in order to understand how to mitigate these limitations to develop/improve future processes. The aim of this study was to evaluate a fertiliser-drawn forward osmosis (FDFO) system by investigating the effects of membrane orientation, system flow rate, DS concentration, and membrane fouling on an FDFO systems performance and energy consumption. The FS used was synthetic brackish water with a sodium chloride (NaCl) content of 5 g/L whereas a potassium chloride (KCl) synthetic fertiliser was used as a DS. The membrane utilised was a cellulose triacetate (CTA) membrane and was tested in forward osmosis mode (FO mode) and pressure retarded osmosis mode (PRO mode) whilst the system flow rate was adjusted between 100, 200 and 400 mL/min. Additionally, the DS concentration was altered from 0.5, 1 and 2 M KCl, respectively. Experiments were performed using a bench scale FO setup which comprised of an i) FO membrane cell, ii) a double head variable peristaltic pump for transporting FS and DS’s respectively, iii) a digital scale to measure the mass of the DS, iv) a magnetic stirrer to agitate the FS, v) two reservoirs for the FS and DS, respectively, vi) a digital multiparameter meter to determine FS electrical conductivity (EC) and vii) a digital electrical multimeter to measure system energy consumption. Each experiment comprised of seven steps i) pre-FDFO membrane control, ii) membrane cleaning, iii) FDFO experiment, iv) post-FDFO membrane control, v) membrane cleaning, vi) membrane damage dye identification and vii) membrane cleaning. Pre- and post-FDFO membrane control experiments operated for 5 h whilst each membrane cleaning procedure operated for 30 min. The FDFO experiment operated for 24 h whilst the membrane damage dye identification operated until a minimum of 10 mL water was recovered. The process parameter which largely contributed to a beneficial system performance and specific energy consumption (SEC) was the increase in DS concentration. Water fluxes increased approximately threefold from a DS concentration increase from 0.5 to 1 M, followed by an additional 30 to 50 % rise in water flux at a DS concentration increase 1 to 2 M. SEC decreased by 58 and 53 % for FO and PRO modes, respectively, with a DS concentration increase from 0.5 to 1 M. An additional 35 and 37 % SEC reduction for FO and PRO modes was obtained for a DS concentration increase from 1 to 2 M. Altering the membrane from FO to PRO did not contribute to a beneficial system performance nor did it improve SEC. However, at a DS concentration of 0,5 M, the PRO mode obtained a 5.3 % greater water recovery compared to the FO mode. Conversely, at a DS concentration of 1 and 2 M, the FO mode achieved 5.4 and 7.0 % greater water recoveries compared to the PRO mode. The increase in flow rate also did not increase system performance significantly, however, a fluctuation in system SEC was observed. Throughout the study, no membrane fouling was observed, however, possible minute traces of membrane fouling could be observed from the membrane surface electron microscope (SEM) images. Additionally, minor changes in post- FDFO membrane control water recovery results were noticed which support the possible occurrence of membrane fouling during the FDFO experiment.
24
Lee, Dowon. "Simulation of phosphorus transport in vegetative filter strips." Diss., Virginia Polytechnic Institute and State University, 1987. http://hdl.handle.net/10919/77815.
Анотація:
This study investigated the effectiveness of vegetative filter strips (VFS) in removing phosphorus from surface runoff. Dissolved and particulate nutrients were treated separately due to differing transport and removal mechanisms. Nutrient transport in VFS appears to be a function of runoff rate, concentration and size distribution of suspended solids, and biological factors that influence hydrologic and chemical processes in filter strips.
Three sets of experimental field plots were constructed to simulate VFS. Each set consisted of three plots containing sediment and nutrient source areas and 0.0, 4.6, or 9.1 m grass filter strips. Artificial rainfall was applied to the plots, and surface runoff, soil, and plant material samples were collected and physically and chemically analyzed. The VFS reduced surface runoff, suspended solids, and phosphorus losses. Most removal of sediment and phosphorus was accomplished in the first few meters of the VFS. The filter strips did not remove phosphorus as effectively as sediment, due to their ineffectiveness for filtering dissolved phosphorus and sediment-bound phosphorus associated with fine particles. The VFS often increased orthophosphorus losses in surface runoff. Laboratory batch experiments of phosph~rus desorption reaction suggested that plant residues, living plant canopy, and soil components of the strips could release dissolved phosphorus to surface runoff. A modified Elovich equation and a diffusion-control model were used to describe the phosphorus release from the plant and soil materials.
A computer model, GRAPH, was developed to simulate phosphorus transport in VFS by incorporating phosphorus transport submodels into the VFS model in SEDIMOT II, a stormwater and sediment transport model. The model considers the effects of advection processes, infiltration, biological uptake, phosphorus desorption from the soil surface to runoff, the adsorption of dissolved phosphorus to suspended solids in runoff, and the effects of dynamic changes in the sediment size distribution on chemical transport.
GRAPH was verified using the results of the physical plot simulations. The model's predictions and observed phosphorus transport compared favorably. Sensitivity analysis suggested that sediment and phosphorus removal was sensitive to the input parameters in the order: filter length and width, grass spacing, and filter slope and surface roughness. Increased filter width and length and aboveground biomass increased orthophosphorus loss from VFS.Ph. D.
25
Shah, Amisha D. "Antibiotics in water treatment the role of water quality conditions on their fate and removal during chlorination and nanofiltration /." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/26658.
Анотація:
Thesis (Ph.D)--Civil and Environmental Engineering, Georgia Institute of Technology, 2009.Committee Co-Chair: Huang, Ching-Hua; Committee Co-Chair: Kim, Jae-Hong; Committee Member: Li, Qilin; Committee Member: Mulholland, James; Committee Member: Wine, Paul; Committee Member: Yiacoumi, Sotira. Part of the SMARTech Electronic Thesis and Dissertation Collection.
26
Micó, Reche Mª del Mar. "Photo-Fenton and Slow Sand Filtration coupling for hydroponics water reuse." Doctoral thesis, Universitat de Barcelona, 2013. http://hdl.handle.net/10803/128571.
Анотація:
The collaboration between the University of Barcelona and Acciona Agua was focused on optimizing greenhouses hydric resources. The functionality of a combined treatment had to be assessed, when applied to the discard stream of a recycling system of the Advanced Greenhouse leachates. The coupling consisted on an Advanced Oxidation Processes (AOP), photo-Fenton, based on hydroxyl radical oxidative potential, produced by the interaction between Fe2+ and H2O2, and a slow sand filtration column acting as a bioreactor. The recycling system will require the synergy of chemical and biological processes to be able to work efficiently with the particular characteristics of greenhouses effluents: high salinity content and the presence of pesticides.
Two recycling strategies proposed by the project defined two conductivity thresholds that the coupled system should be able to cope with. The first strategy proposed a simple semi-closed system that recycled nutrient solution from the hydroponics crops until a maximum value of 11 mS•cm(-1), phytotoxicity limit. Part of the current was then diverted to be treated by the integrated system. The second strategy introduced reverse osmosis membrane technology that concentrated that diverted stream, sending the permeate for its reuse directly to the greenhouse, while the brine had to be treated by the coupled process. In this case the maximum level of salinity in the effluents could reach conductivities close to those for seawater, around 50 mS•cm(-1).
The performance of photo-Fenton reaction was essayed in order to improve the knowledge regarding this treatment technique. On the first place, this AOP and the ozonation process were compared. Results shown that increasing toxicity of ozonation effluents confirmed the choice of photo-Fenton as the most adequate treatment for pesticide polluted effluents. Experimental design criteria allowed then to determine optimal working conditions depending on the content of the reaction media, and enabled to prove the existence of endogenous catalyst inhibition in the presence of fosetyl-Al. Salinity essays were finally performed, yielding positive results even for highest conductivity effluents. Those positive results were also reflected in the increase of the biodegradability of the treated effluents, what leaded to the next step of the research.
Biocompatibility of pretreated effluents was essayed by means of sequencing batch reactors (SBR). These devices were used to show how photo-Fenton indeed increased biodegradability of the effluents, and how it grown until a certain point when more hydrogen peroxide did not lead to better results. They were also utilized to assess the biocompatibility of high salinity pretreated effluents, as a first step towards the coupling with the slow sand filtration at high conductivities. Results obtained were extremely encouraging, given that even for the highest salinity concentrations (10 and 50 mS•cm(-1)), the performance of the bioreactor achieved an organic content reduction for more than 80% of the loaded concentration, which compared to the 10-20% removal achieved by photo-Fenton, justifies the need of combining both treatments.
Guided by those positive results, the load of the slow sand filtration column with different salinity pretreated effluents was performed. Also positive results were obtained. The achieved elimination of the organic content was more than 75% when loaded with 10 mS•cm-1 effluent, and the refractory fraction (the remaining organic matter that cannot be oxidized either by photo-Fenton reaction or by the biomass metabolism) was the lowest also for this high conductivity.
Molecular biology tools, MTBs, used in this thesis were based on cloning and sequencing techniques of 16S rRNA genes. They allowed characterizing the bacterial population of one of the assessed SBRs and of the different loading stages of the slow sand filtration column. They showed how with the increase of salinity, the population in the slow sand filtration column loosed diversity, despite the fact that the performance of the column was still proficient. This fact stated how a very different microbial consortium could be developing the same functions as others.
According to obtained results, it could be finally concluded that the coupling between photo-Fenton reaction and slow sand filtration column could be an effective treatment alternative for implementing the recycling strategies of hydroponics greenhouse leachates proposed by CENIT-MEDIODIA Project. For its part, MBTs were revealed as powerful tools to characterize microbial population and increase the understanding of the bioreactions taking part in bioremediation.Esta tesis se enmarca en la colaboración entre el Departamento de Ingeniería Química de la Universidad de Barcelona y el Departamento de I+D de Acciona Agua S.A.U, en el marco del Proyecto CENIT- MEDIODIA (2007-2010). Esta iniciativa la componen un consorcio de empresas un consorcio de empresas y centros de investigación que unieron esfuerzos de innovación en el desarrollo de un nuevo concepto de Invernaderos Hidropónicos Avanzados. La colaboración entre la Universidad de Barcelona y Acciona Agua se centró en la optimización de los recursos hídricos de dichos invernaderos. Así se evaluó la funcionalidad de un tratamiento combinado que integrara un Proceso de Oxidación Avanzada (reacción foto-Fenton), y un reactor biológico (columna de arena de filtración lenta), aplicados a la corriente de desecho de un sistema de recirculación de lixiviados provenientes del nombrado invernadero avanzado. Las particularidades de dicho sistema de reciclado harían que el sistema combinado tuviese que trabajar con efluentes con alto contenido en pesticidas (metomilo, imidacloprid y fosetyl-Al, fueron escogidos para simular los lixiviados de invernadero) y conductividades entre 11 y 50 mS•cm-1. De este modo el principal objetivo del proceso integrado sería el de conseguir la máxima eliminación de los compuestos xenobióticos y de la carga orgánica que los acompañe en el efluente tratado. Así pues, la experimentación se llevó a cabo frente a tres aspectos relacionados con el sistema combinado: estudio de la reacción foto-Fenton, ensayos con biorreactores, y empleo de herramientas de biología molecular (MBT, en sus siglas en inglés) aplicadas a la caracterización de la biomasa desarrollada en los biorreactores ensayados. Según los resultados obtenidos, se llegó a la conclusión de que la combinación de la reacción foto-Fenton y la columna de filtración lenta podría ser una alternativa de tratamiento eficaz para la aplicación de las estrategias de reciclaje de los lixiviados hidroponía presentadas en Proyecto CENIT-MEDIODIA. Además, MBT se revelaron como poderosas herramientas para caracterizar la población microbiana de distintos biorreactores y las funciones que desempeñan.
27
Melamane, Xolisa. "Cleaning of fouled membranes using enzymes from a sulphidogenic bioreactor." Thesis, Rhodes University, 2004. http://hdl.handle.net/10962/d1015764.
Анотація:
Maintenance of membrane performance requires inevitable cleaning or defouling of fouled membranes. Membrane cleaning using enzymes such as proteases, lipases, α-glucosidases from a sulphidogenic bioreactor was investigated. At first, dilute and concentrated enzyme extract were prepared form the sulphidogenic pellet. Enzyme assays on 0.5 % azocaisen, 1 % triacetin and 1 mg/ml ρ-nitrophenyl-α-D-glucopyranoside were performed using the concentrated enzyme extract (0 – 200 mg/ml). For membrane fouling, an abattoir effluent was obtained from Ostritech Pty (Ltd), Grahamstown, South Africa. The effluent was characterised for presence of potential foulants such as lipids, proteins, amino acids and carbohydrates. Static fouling of polysulphone membranes (0.22 μm, 47 mm) was then performed using the abattoir effluent. Cleaning of the fouled membranes was also performed using at first the dilute and then the concentrated form (200 mg/ml) of enzyme extracts. Qualitative and quantitative biochemical analysis for proteins, lipids and carbohydrates was performed to ascertain the presence of foulants on polysulphone membranes and their removal by dilute or concentrated enzyme extracts. The ability of dilute enzyme extracts to remove proteins lipids, and carbohydrates fouling capillary UF membrane module; their ability to restore permeate fluxes and transmembrane pressure after cleaning/defouling was also investigated. Permeate volumes from this UF membrane module were analysed for protein, amino acids, lipids, and carbohydrates concentrations after fouling and defouling. Fouling was further characterized by standard blocking, cake filtration and pore blocking models using stirred UF cell and polyethersulphone membranes with MWCO of 30 000, 100 000 and 300 000. After characterization of fouling, polyethersulphone membranes with MWCO of 30 000 and 300 000 were defouled using the concentrated enzyme extract (100 mg ml). Enzyme activities at 200 mg/ml of enzyme concentration were 8.071 IU, 86.71 IU and 789.02 IU for proteases, lipases and α-glucosidases. The abattoir effluent contained 553 μg/ml of lipid, 301 μg/ml of protein, 141 μg/ml of total carbohydrate, and 0.63 μg/ml of total reducing sugars. Proteins, lipids and carbohydrates fouling polysulphone membranes after a day were removed by 23.4 %, when a dilute enzyme was used. A concentrated enzyme extract of 200 mg/ml was able to remove proteins, lipids and carbohydrates up to 5 days of fouling by 100 %, 82 %, 71 %, 68 % and 76 % respectively. Defouling of dynamically fouled capillary ultrafiltration membranes using sulphidogenic proteases was successful at pH 10, 37°C, within 1 hour. Sulphidogenic proteases activity was 2.1 U/ml and flux Recovery (FR %) was 64. Characterization of fouling revealed that proteins and lipids were major foulants while low concentration of carbohydrates fouled polyethersulphone membranes. Fouling followed standard blocking for 10 minutes in all the membranes; afterwards fouling adopted cake filtration model for membranes with 30 000 MWCO and pore blocking model for membranes with 300 000 MWCO. A concentration of 100 mg/ml of enzyme extract was able to remove fouling from membranes with MWCO of 30 000. Defouling membranes that followed pore blocking model i.e. 300 000 MWCO was not successful due to a mass transfer problem. From the results of defouling of 30 000 and 300 000 MWCO it was concluded that defouling of cake layer fouling (30 000 MWCO) was successful while defouling of pore blocking fouling was unsuccessful due to a mass transfer problem. The ratio of enzymes present in the enzyme extract when calculated based on enzymatic activity for proteases, lipases and α-glucosidases was 1.1 %, 11 % and 87.9 %. It was hypothesized that apart from proteases, lipases, α and β-glucosidases; phosphatases, sulphatases, amonipeptidases etc. from a sulphidogenic bioreactor clean or defoul cake layer fouling by organic foulants and pore blocking fouling provided the mass transfer problem is solved. However, concentration of enzymes from a sulphidogenic bioreactor has not been optimized yet. Other methods of concentrating the enzyme extract can be investigated for example use of organic solvents.
28
Smith, Everhardus Johannes. "A numerical analysis of the hydrodynamic mixing characteristics of a rectangular versus a cylindrical mixing crystallizer tank for a membrane distillation apparatus." Thesis, Cape Peninsula University of Technology, 2018. http://hdl.handle.net/20.500.11838/2827.
Анотація:
Thesis (MTech (Mechanical Engineering))--Cape Peninsula University of Technology, 2018.A membrane distillation crystallization (MDC) experimental setup was designed, constructed and commissioned with rectangular mixing crystallizer tanks. The advantages and disadvantages of a rectangular mixing tank are compared to the traditional cylindrical mixing tank with baffling by means of a computational fluid dynamic (CFD) analysis in Ansys Fluent. The effect of tank configuration and geometry on the hydrodynamic and mixing characteristics for efficient momentum, solid suspension, heat and mass transfer were investigated. The hydrodynamic conditions in a crystallizer-mixing tank determine the quality of fluid mixing essential for optimal crystallization. Forty-five degree pitched blade turbines (PBT) were used to provide the agitation in the stainless steel rectangular jacketed tanks. Clear polycarbonate replicas of the rectangular tanks were manufactured to visually observe the mixing process in the tanks. Silica particles were used to represent the calcium carbonate crystals in the experiment. The data gathered from these experiments showed that the tanks should be operated between 600 to 750 rpm in the CFD simulations to simulate partial to complete suspension. In the numerical simulations a rectangular tank was compared to a cylindrical tank with baffling of the same volume. The partial differential equations solved in the numerical simulation were the conservation of mass (continuity), conservation of momentum and additional turbulence equations. In order to solve the turbulent fluid flow characteristics, the industry standard two-equation model, namely the K-epsilon model was used. This model was refined by the addition of the Wen-Yu drag model, the Simonin turbulent dissipation and the Simonin et al. turbulence interaction models. The RANS based RNG (k-ε), derived from the instantaneous Navier-Stokes equation was selected as the preferred model to analyse the hydrodynamic flow fields in the tanks. The 3D sliding mesh method was used to compute a time accurate solution. The Eulerian-granular multiphase model was used to predict the degree of solids suspension in the tanks. The efficiency of mixing within the tank was measured by the tank’s ability to keep the crystals in suspension and preventing any particle from settling at the bottom for more than 1-2 second(s). The mixing tanks were initially loaded with 5% v/v, which equates to a loaded height of approximately 10 mm. The simulations were done with the use of the volume fraction function to visually observe the cloud height and gauge the homogeneity and distribution of the particulates within the fluid flow fields. The results from the experimental setup were compared to the CFD simulations to qualify the use of CFD simulations for the comparison of the geometrically different tanks. Lastly, the findings from the CFD simulations were used to compare the tanks and determine if the rectangular tank built for the MDC experiment perform satisfactorily to replace a standard cylindrical tank with baffling for this application.
29
Hakami, Mohammed Wali. "Humic acid removal and fouling using tubular ceramic microfiltration membranes combined with coagulation." Thesis, Swansea University, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.678502.
30
Du, Plessis Danielle Marguerite. "Fabrication and characterization of anti-microbial and biofouling resistant nanofibers with silver nanoparticles and immobilized enzymes for application in water filtration." Thesis, Stellenbosch : University of Stellenbosch, 2011. http://hdl.handle.net/10019.1/6580.
Анотація:
Thesis (MSc (Biochemistry))--University of Stellenbosch, 2011.ENGLISH ABSTRACT: Due to a global lack of access to potable water, a problem particularly affecting people in developing countries and the poor, improvement on existing water purification methods are necessary to provide more cost effective, accessible and efficient methods of water purification. In drinking water systems, biofilms are a potential source of contamination, which can affect the biological stability and hygienic safety of water. In industrial water systems, biofilms can cause corrosion, resistance in flow systems and a decrease in efficiency of membranes. Nanotechnology has been identified as a technology to utilize in water purification problem solving. Alternatives to the use of chemical biocides and antibiotics need to be investigated therefore; the focus of this study was the fabrication and characterization of polymer nanofibers containing silver nanoparticles as biocide and anti-biofouling nanofibers with hydrolytic enzymes immobilized on the surface. The aim of this study was to synthesize and compare poly (vinyl alcohol) (PVA) nanofibers and poly (acrylonitrile) (PAN) nanofibers with silver nanoparticles to determine which type of fiber will be the most appropriate for application in water sanitation. The two types of fibers were to be compared based on morphology, silver nanoparticle content, physical distribution of silver nanoparticles, levels of silver leaching from the fibers in water, which could imply toxicity, and most importantly, anti-microbial efficacy. Back scattering electron images revealed that silver nanoparticles in PVA nanofibers were more evenly dispersed than in PAN nanofibers, but that PAN nanofibers had higher silver nanoparticle content. This was confirmed by energy dispersive X-ray (EDX) analysis. Both PVA and PAN nanofibers containing silver nanoparticles had excellent anti-microbial activity, with PVA nanofibers killing between 91% and 99% of bacteria in a contaminated water sample and PAN nanofibers killed 100%. When investigated by SEM, the biocidal effect of PAN nanofibers containing silver nanoparticles can be observed as morphological changes in the cell walls. Neither PVA nor PAN nanofibers leached silver into water. PVA is a non-toxic and biodegradable synthetic polymer, and PVA-silver nanofibers have excellent anti-microbial activity, making it applicable in water sanitation in an environmental conscious milieu. PAN nanofibers are more conductive to the formation of silver nanoparticles, have higher silver nanoparticle content, allowing the complete sanitation of pathogenically contaminated water samples. PAN nanofibers also have better longevity and strength in water, making it ideal for water filtration and sanitation in higher throughput systems. Furthermore, immobilized enzymes are being investigated as possible alternatives to inefficient conventional methods of controlling and removing biofilms from filtration systems. This study demonstrates the covalent immobilization of two industrial proteases and an amylase enzyme onto polymer nanofibers widely used in filtration membranes. Confirmed by FTIR, these nanofibers were successfully activated by amidination, allowing the covalent immobilization of respectively two serine proteases and an α-amylase onto the fibers. When inspected visually, fibers largely retained their original morphology after activation and enzyme immobilization. Immobilized enzymes were, however visible as aggregated particles on the nanofiber surfaces. The large surface area to volume ratio provided by the nanofibers as immobilization surface, allowed sufficient amounts of enzymes to be immobilized onto the fibers so that all enzymes retained above 80% of the specific activity of the free enzymes. For each of the immobilized enzymes, just below 30% of initial activity was retained after 10 repeated cycles of use. Fibers with immobilized enzymes on their surface did not support the growth of biofilms, as opposed to plain nanofibers, which did support the growth of biofilms. When considering the combined advantages of this effective immobilization process, the robustness of the enzymes used in this study, and their effectiveness against biofilms in their immobilized state, a valuable addition has been made to technology available for the control of biofilm formation on filtration membranes, and could potentially be employed to control biofilm formation in water filtration systems. A combination of anti-microbial and anti-biofouling nanofibers into a single nanofiltration product may prove to be highly applicable in water sanitation systems.
AFRIKAANSE OPSOMMING: As gevolg van 'n wêreldwye gebrek aan toegang tot drinkbare water, 'n probleem wat veral mense in ontwikkelende lande en armes raak, is dit van belang dat bestaande metodes van watersuiwering verbeter word om voorsiening te maak vir meer koste-effektiewe, toeganklike en doeltreffende metodes van watersuiwering. In drinkwater stelsels is biofilms 'n potensiële bron van besoedeling, wat die biologiese stabiliteit en die higiëniese veiligheid van water beïnvloed. In industriële waterstelsels kan biofilms tot die verwering van pyplyne lei, weerstand in die stroomstelsels veroorsaak en 'n afname in die doeltreffendheid van membrane veroorsaak. Nanotegnologie is geïdentifiseer as 'n tegnologie wat aangewend kan word in watersuiwerings probleemoplossing. Alternatiewe vir die gebruik van chemiese antimikrobiese middels moet dus ondersoek word. Hierdie studie fokus dus op die vervaardiging en karakterisering van polimeer nanovesels met silwer nanopartikels wat ingesluit is as antimikrobiese middel en anti-biofilm vesels met hidrolitiese ensieme geïmmobiliseer op die oppervlak. Die doel van hierdie studie was om poli (viniel alkohol) (PVA) nanovesels en poli (akrielonitriel) (PAN) nanovesels te sintetiseer waarby silwer nanopartikels ingesluit is, en te bepaal watter tipe vesel die mees geskikte sal wees vir die gebruik in water sanitasie. Die twee tipes vesels is met mekaar vergelyk gebaseer op morfologie, silwer nanopartikel inhoud, fisiese verspreiding van silwer nanopartikels, vlakke van silwer uitloging vanuit die vesels in water, wat toksisiteit tot gevolg kan hê, en die belangrikste, antimikrobiese effektiwiteit. Terug verstrooiing elektron beelde het aan die lig gebring dat die silwer nanopartikels in PVA nanovesels meer eweredig versprei was as in PAN nanovesels, maar dat PAN nanovesels 'n hoër silwer nanopartikel inhoud gehad het. Dit is bevestig deur “energy dispersive X-ray” (EDX) analise. Beide PVA en PAN nanovesels met silwer nanopartikels het uitstekende antimikrobiese aktiwiteit getoon, met PVA vesels wat tussen 91% en 99% bakterieë in besoedelde water monsters kon doodmaak en PAN vesels wat 100% bakterieë kon uitwis. Wanneer vesels ondersoek is met ʼn skandeer elektronmikroskoop (SEM), kon die antimikrobiese effek van PAN vesels met silwer nanopartikels as morfologiese veranderinge in die selwande waargeneem word. Nie PVA of PAN nanovesels loog silwer uit in water nie. PVA is 'n nie-toksiese en bioafbreekbare sintetiese polimeer, en PVA-silwer nanovesels het uitstekende antimikrobiese aktiwiteit, wat dit van toepassing maak op water sanitasie in ʼn omgewings bewuste milieu. PAN vesels is meer gunstig tot die vorming van silwer nanopartikels, en het 'n hoër silwer nanopartikel inhoud, dus word patogeen besoedelde water volledig gesteriliseer. PAN vesels het ook 'n beter langslewendheid en weerstandige sterkte in water, wat dit ideaal vir water filtrasie en sanitasie in hoër deursettings stelsels maak. Geïmmobiliseerde ensieme word ook ondersoek as moontlike alternatiewe tot ondoeltreffende konvensionele metodes van beheer en die verwydering van biofilms uit water stelsels. Hierdie studie toon die kovalente immobilisasie van twee industriële proteases en 'n amilase ensiem op polimeer vesels wat gebruik word in filtrasie membrane. Bevestig deur FTIR, is PAN vesels suksesvol geaktiveer deur amidinasie, sodat die kovalente immobilisasie van onderskeidelik twee serien proteases en 'n α-amilase op die vesels moontlik is. Met visuele ondersoek kan gesien word die vesels behou grootliks hul oorspronklike morfologie na aktivering en ensiem immobilisasie. Geïmmobiliseerde ensieme is egter sigbaar as saamgevoegde deeltjies op die nanovesel oppervlaktes. Die groot oppervlakarea: volume-ratio van die vesels wat dien as immobilisasie oppervlak, laat toe dat voldoende hoeveelhede van ensieme geïmmobiliseer word sodat alle ensieme meer as 80% van die spesifieke aktiwiteit van die vrye ensieme behou. Vir elk van die geïmmobiliseer ensieme, is net minder as 30% van die aanvanklike aktiwiteit behou na 10 siklusse van hergebruik. Vesels met geïmmobiliseerde ensieme op hul oppervlaktes het nie die groei van biofilms ondersteun nie, in teenstelling met gewone vesels, sonder ensieme, wat die groei van biofilms ondersteun. As die gesamentlike voordele van hierdie doeltreffende immobilisasie proses, die robuustheid van die ensieme en hulle doeltreffendheid teen biofilms in hul geïmmobiliseerde toestand in ag geneem word, is ʼn waardevolle toevoeging gemaak tot tegnologie wat beskikbaar is vir die beheer van biofilm vorming op filtrasie membrane, en dit kan potensieel gebruik word om biofilm vorming filter stelsels te beheer. Die kombinasie van anti-mikrobiese en anti-biofilm vesels in ʼn enkele nanofiltrasie produk moet nagestreef word, omdat dit hoogs van toepassing sal wees in water sterilisasie stelsels.
31
Kieffer, Daniel W. "Feasibility of recycling air conditioner condensate for use as process water for a manufacturing facility." Oklahoma City : [s.n.], 2008.
32
Franco, Monalisa 1984. "Uso de coagulante extraído de sementes de Moringa oleifera como auxiliar no tratamento de água por filtração em múltiplas etapas." [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/256904.
Анотація:
Orientador: José Euclides Stipp PaternianiDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola
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Resumo: A água é recurso indispensável para a sobrevivência do ser humano. Em comunidades onde os sistemas convencionais de tratamento de água enfrentam difícil implantação é necessária a busca por tecnologias adequadas. Os filtros lentos apesar da simples manutenção e baixo custo se tornaram limitados devido à degradação da qualidade dos mananciais, sendo necessário o uso de pré-tratamentos para melhoria da qualidade de água para o seu emprego. Coagulantes naturais, dentre eles aquele produzido a partir de sementes de Moringa oleifera são alternativas para o tratamento de água para regiões desprovidas de tecnologias convencionais. Portanto, o objetivo deste trabalho é avaliar a influência de diferentes dosagens do coagulante natural de Moringa oleifera na eficiência das etapas do sistema de filtração em múltiplas etapas no tratamento de água. O sistema foi constituído por pré-filtro dinâmico, pré-filtros de fluxo ascendente e filtros lentos, e em alguns ensaios por floculador granular. Em seguida, foram definidas as dosagens de 131mg.L-1 de solução coagulante de Moringa oleifera a ser aplicada na etapa da pré-filtração e 106 mg.L-1 e 53mg.L-1 a serem aplicadas nas etapas de filtração lenta, que poderiam passar pelo floculador ou não. No filtro lento em que houve a introdução da solução coagulante foram testados primeiramente três camadas de mantas não tecidas de gramatura de 400g.m-2 e em seguida uma camada de 150 g.m-2 no topo da camada de areia. A aplicação da solução coagulante proporcionou na etapa da pré-filtração, média de turbidez de 11NTU e cor aparente de 73mg.L-1 PtCo. Na etapa da filtração lenta esses valores foram 1,15NTU e 11mg.L-1PtCo, para dosagem de 106mg.L-1 de Moringa oleifera e de 5NTU e 42mg.L-1PtCo para a dosagem de 53mg.L-1 da solução coagulante. A aplicação de apenas uma camada de manta não tecida no topo do meio filtrante do filtro lento demonstrou ser benéfica para o sistema, pois manteve o alto índice de eficiência de remoção de turbidez e cor aparente. Deste modo conclui-se que o uso do coagulante extraído das sementes de Moringa oleifera melhorou a eficiência do tratamento de água pelo sistema de filtração em múltiplas etapas, principalmente quando o coagulante foi aplicado na etapa de pré-filtração. Entretanto, a aplicação direta da solução coagulante no filtro lento causou rápida colmatação da manta e menor tempo de duração da carreira, além disso a passagem da solução coagulante pelo floculador granular não apresentou resultados satisfatórios
Abstract: Water is the most important resource for human survival. In communities where the conventional water treatment faces difficult deployment is necessary to search for simple technologies. Simple maintenance and low cost are presented for slow sand filter, however the water degradation has limited this operation system and now pre treatments are necessary for using this technology. Natural coagulants and among them those produced from Moringa oleifera seeds are alternatives for water treatment in regions where there is not conventional technologys. Therefore, this study aims is evaluate the influence of different dosages of natural coagulant extracted from Moringa oleifera seeds on multistage filtration system. The system was composed with dynamic roughing filter, uplflow roughing filters, slow sand filters and some tests by granular flocculator. The dosage of 131mg.L-1 of Moringa oleifera solution was defined to be applied on upflow roughing filter and the dosages of 106mg.L-1 and 53mg.L-1 on slow sand filter, which could pass through flocculator or not. The slow sand filter that received the coagulant solution was tested with three layers of nonwoven blankets with 400g/m² and afterward with one layer of nonwoven blanket with 150g/m² at the top of the sand. After the application of natural coagulant solution in upflow roughing filter, the mediums values of turbidity and apparent color were 11NTU and 73mg.L-1 PtCo, respectively. In slow sand filtration stage these values were 1,15NTU and 11mg.L-1PtCo for the dosage of 106mg.L-1 of Moringa oleifera, and 5NTU and 42mg.L-1PtCo for the dosage of 53mg.L-1 of the coagulant solution. The application of a single layer of nonwoven blanket on top of slow sand filter proved to be beneficial to the system because it maintained a high rate of removal efficiency of turbidity and apparent color. Thus it is concluded that the use of coagulant extracted from Moringa oleifera seeds improved the efficiency of water treatment by multistage filtration system. However, the direct application of the coagulant solution into the slow sand filter caused rapid clogging of the blanket and shorter career length. Furthermore, unsatisfying results was showed from the passage of the coagulant solution by granular flocculator
Mestrado
Agua e Solo
Mestre em Engenharia Agrícola
33
Marais, Pierre Charl. "The hydrodynamic characterisation of an axial-flow membrane module." Thesis, Stellenbosch : Stellenbosch University, 2001. http://hdl.handle.net/10019.1/52531.
Анотація:
Thesis (MScEng)--University of Stellenbosch, 2001.ENGLISH ABSTRACT: The hydrodynamics of a hollow fibre membrane module for the ultrafiltration of potable water were investigated. The purpose was to use a hydrodynamic model to predict the permeate flux for modules of various dimensions. Various models were considered, but most of them could not account for important effects such as macroscopic radial gradients and wet fibre expansion, found in hollow-fibre membrane modules. The Porous Medium Model was found to be a suitable model and it was used together with a finite element software package, Fastflo, to solve for the pressure distributions inside the membrane modules and predict permeate flux. The permeability of the membranes was obtained using a combination of numerical and experimental procedures and was found to be 2.3 x 10-13m. A cost analysis was performed to find the most economical module dimensions (outer diameter and length) for any required product flow rate. It was assumed that the cost of the fibres and module housing comprised the capital cost, while the operating cost consisted of the pumping energy. A capital recovery factor of 0.3 was used to convert capital costs to a yearly cost. It was found that the optimum module dimensions are an outer diameter of between 90mm and 160mm and a length of 0.6m. Finally the pressure distributions on the lumen and shell sides during both cross-flow filtration and backwash were examined. Shade plots proved useful for identifying possible areas of stagnant flow, as well as indicating where backwash is the most effective.
AFRIKAANSE OPSOMMING: Die hidrodinamika binne-in 'n holvesel membraanmodule vir die ultrafiltrasie van drinkwater is ondersoek. Die doel was om 'n hidrodinamiese model te gebruik om die permeaatvloed vir modules van verskeie dimensies te voorspel. Verskillende modelle is oorweeg, maar die meeste kon nie belangrike faktore soos makroskopiese radiale drukqradiente of nat veselverlenging in ag neem nie. Die Poreuse Medium Model was die mees geskikte model en is gebruik saam met Fastf/o, 'n sagteware pakket wat gegrond is op die eindige element metode, om vergelykings vir die drukverspreiding binne-in die module op te los en permeaatvloed te voorspel. Die permeabiliteit van die membrane is verkry met behulp van numeriese en eksperimentele prosedures en 'n waarde van 2.3 x 10-13 m is bepaal. Hierna is 'n koste-analise uitgevoer om die mees ekonomiese module afmetings (Iengte en buitedeursnit) te bepaal vir 'n gegewe produk vloeitempo. Daar is aanvaar dat kapitaalkoste bestaan uit die koste van vesels en module-omhulsel, terwyl bedryfskoste bereken is deur die hoeveelheid energie benodig om die pomp aan te dryf. 'n Kapitaalherwinningsfaktor van 0.3 is gebruik om kapitaalkoste om te skakel na 'n jaarlikse koste. Die optimum module afmetings is 'n lengte van 0.6m en 'n buite-deursnit van tussen 90mm en 160mm. Laastens is die drukverspreidings tydens beide kruisvloeifiltrasie en die terugspoelproses ondersoek. Areas van stagnante vloei kan deur middel van skadu-grafieke geYdentifiseer word, terwyl dit ook moontlik is om die terugspoelproses te optimeer.
34
Powell, Lydia Charlotte. "The biofouling of reverse osmosis membranes : from characterisation to control." Thesis, Swansea University, 2011. https://cronfa.swan.ac.uk/Record/cronfa42695.
Анотація:
Membrane technology can be utilised for the high purification and desalination of water. However membrane filtration processes are commonly impeded by membrane fouling, which can lead to flux decline and an overall reduction in separation efficiency within the process. Therefore the aim of this research study was a comprehensive investigation of the issue of biofouling on industrial RO membranes through molecular biology techniques, characterisation of surface charge of foulant bacteria and RO membrane surface and AFM imaging and force measurements on clean and fouled membranes for the determination of adhesion force and micromechanical properties. The laboratories within Gwangju Institute of Science and Technology, South Korea and Swansea University, Wales were equipped for the scope of this research work. Research focused on the extraction of microbial DNA obtained from fouling layers on the surface of Reverse Osmosis Membranes obtained from the Fujairah Water and Power Plant, UAE. The use of the culture independent method of the molecular technique based on the 16S rDNA sequence and constructed gene libraries, was then used to determine the bacterial species that caused significant fouling on the RO membrane. Four bacterial species isolated from the fouling layer from the RO membrane were characterised in terms of electrophoretic mobility and zeta potential to determine the cell surface charge within various industrial relevant environments for the elucidation of cell adhesion mechanisms to the membrane surface. AFM images of virgin and fouled membranes were obtained and analysed to reveal the roughness of the surface which could influence fouling and the surface charge of the membranes were measured through the method of streaming potential at various industrial relevant environments to further elucidate the mechanisms of cell adhesion to the membrane surface. Force measurements were performed to reveal the adhesion force and elasticity values of virgin, process fouled and purposely fouled with the four bacterial isolates, to determine process behaviour in various environmental conditions. Through this research and future work, it is hoped that a rational strategy for economic and effective cleaning processes will be developed which will maintain efficient membrane operation and prolong membrane life, thus enabling the reduction of operating costs of such processes.
35
Heleva-Ponaski, Emily. "Removal Efficiencies, Uptake Mechanisms and Competitive Effects of Copper and Zinc in Various Stormwater Filter Media." PDXScholar, 2018. https://pdxscholar.library.pdx.edu/open_access_etds/4556.
Анотація:
Polluted stormwater, if not treated, can compromise water quality throughout our hydrologic cycle, adversely affecting aquatic ecosystems. Common stormwater pollutants, copper and zinc, have been identified as primary toxicants in multiple freshwater and marine environments. For small-scale generators, stormwater management can be cumbersome and implementation of common BMPs impractical thus catch basins are popular though not the most environmentally conscious and sustainable option. This study aims to characterize the potential of a mobile media filter operation for the treatment and on-site recycling of catch basin stormwater. The removal capacities of various commercially available filter media (e.g. a common perlite; Earthlite™, a medium largely composed of biochars; and Filter33™, a proprietary porous medium) were measured using binary injection solutions modeled after local catch basin stormwater characteristics. The results of filtration experiments, rapid small-scale column tests (RSSCTs), indicate that the transport of metals in Perlite is primarily impacted by nonspecific sorption whereas in Earthlite™ and Filter33™ both nonspecific and specific sorption are present. For all media and experimentation, there was a consistent preferential uptake of copper such that copper displayed delayed arrival and/or greater removal than zinc. Moreover, the observed snow plow effects and concentration plateaus in Earthlite™ and Filter33™ RSSCTs suggest rate limited ion exchange and specific sorption in addition to ion competition. Earthlite™ exhibited an approach velocity dependent removal efficiency in the RSSCTs and pseudo second order uptake behavior for zinc in kinetic batch experiments. At the lab scale equivalent of the proposed field scale flow rate, Filter33™ displayed the greatest average zinc removal of 8.6 mg/g. In all, this research indicates that test parameters (i.e. pH, competitive ions solutions, empty bed contact time, flow rate) based on the natural environment and field scale operation can greatly impact removal efficiency in filter media.
36
Boyd, Christopher C. "Effect of acetic or citric acid ultrafiltration recycle streams on coagulation processes." Master's thesis, University of Central Florida, 2011. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4853.
Анотація:
Integrating ultrafiltration (UF) membranes in lieu of traditional media filters within conventional surface water coagulation-flocculation-sedimentation processes is growing in popularity. UF systems are able to produce low turbidity filtered water that meets newer drinking water standards. For typical drinking water applications, UF membranes require periodic chemically enhanced backwashes (CEBs) to maintain production; and citric acid is a common chemical used for this purpose. Problems may arise when the backwash recycle stream from a citric acid CEB is blended with raw water entering the coagulation basin, a common practice for conventional surface water plants. Citric acid is a chelating agent capable of forming complexes that interfere with alum or ferric chloride coagulation. Interference with coagulation negatively affects settled water quality. Acetic acid was investigated as a potential substitute for citric acid in CEB applications. A jar testing study was conducted to compare the impacts of both citric acid and acetic acid on the effectiveness of aluminum sulfate (alum) and ferric chloride coagulants. Citric acid was found to adversely affect coagulation at lower acid to coagulant (A/C) molar ratios than acetic acid, and a coagulation interference threshold was identified for both acids based on settled water turbidity goals recommended by the U.S. Environmental Protection Agency (EPA). Pilot testing was conducted to assess the viability of acetic acid as a UF CEB chemical. Acetic acid CEBs maintained pilot performance in combination with sodium hypochlorite CEBs for filtering a raw California surface water. It is believed that this is the first ultrafiltration membrane process application of acetic acid CEBs for municipal potable water production in the United States.ID: 029810322; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Thesis (M.S.)--University of Central Florida, 2011.; Includes bibliographical references (p. 69-72).
M.S.
Masters
Civil, Environmental and Construction Engineering
Engineering and Computer Science
37
Verrelli, D. I. "Drinking water treatment sludge production and dewaterabilityф". D. I. Verrelli, 2008. http://repository.unimelb.edu.au/10187/3521.
Анотація:
The provision of clean drinking water typically involves treatment processes to remove contaminants. The conventional process involves coagulation with hydrolysing metal salts, typically of aluminium (‘alum’) or trivalent iron (‘ferric’). Along with the product water this also produces a waste by-product, or sludge. The fact of increasing sludge production — due to higher levels of treatment and greater volume of water supply — conflicts with modern demands for environmental best practice, leading to higher financial costs. A further issue is the significant quantity of water that is held up in the sludge, and wasted.One means of dealing with these problems is to dewater the sludge further. This reduces the volume of waste to be disposed of. The consistency is also improved (e.g. for the purpose of landfilling). And a significant amount of water can be recovered. The efficiency, and efficacy, of this process depends on the dewaterability of the sludge.In fact, good dewaterability is vital to the operation of conventional drinking water treatment plants (WTP’s). The usual process of separating the particulates, formed from a blend of contaminants and coagulated precipitate, relies on ‘clarification’ and ‘thickening’, which are essentially settling operations of solid–liquid separation.WTP operators — and researchers — do attempt to measure sludge dewaterability, but usually rely on empirical characterisation techniques that do not tell the full story and can even mislead. Understanding of the physical and chemical nature of the sludge is also surprisingly rudimentary, considering the long history of these processes.
The present work begins by reviewing the current state of knowledge on raw water and sludge composition, with special focus on solid aluminium and iron phases and on fractal aggregate structure. Next the theory of dewatering is examined, with the adopted phenomenological theory contrasted with empirical techniques and other theories.The foundation for subsequent analyses is laid by experimental work which establishes the solid phase density of WTP sludges. Additionally, alum sludges are found to contain pseudoböhmite, while 2-line ferrihydrite and goethite are identified in ferric sludges.
A key hypothesis is that dewaterability is partly determined by the treatment conditions. To investigate this, numerous WTP sludges were studied that had been generated under diverse conditions: some plant samples were obtained, and the remainder were generated in the laboratory (results were consistent). Dewaterability was characterised for each sludge in concentration ranges relevant to settling, centrifugation and filtration using models developed by LANDMAN and WHITE inter alia; it is expressed in terms of both equilibrium and kinetic parameters, py(φ) and R(φ) respectively.This work confirmed that dewaterability is significantly influenced by treatment conditions.The strongest correlations were observed when varying coagulation pH and coagulant dose. At high doses precipitated coagulant controls the sludge behaviour, and dewaterability is poor. Dewaterability deteriorates as pH is increased for high-dose alum sludges; other sludges are less sensitive to pH. These findings can be linked to the faster coagulation dynamics prevailing at high coagulant and alkali dose.Alum and ferric sludges in general had comparable dewaterabilities, and the characteristics of a magnesium sludge were similar too.Small effects on dewaterability were observed in response to variations in raw water organic content and shearing. Polymer flocculation and conditioning appeared mainly to affect dewaterability at low sludge concentrations. Ageing did not produce clear changes in dewaterability.Dense, compact particles are known to dewater better than ‘fluffy’ aggregates or flocs usually encountered in drinking water treatment. This explains the superior dewaterability of a sludge containing powdered activated carbon (PAC). Even greater improvements were observed following a cycle of sludge freezing and thawing for a wide range of WTP sludges.
Further aspects considered in the present work include deviations from simplifying assumptions that are usually made. Specifically: investigation of long-time dewatering behaviour, wall effects, non-isotropic stresses, and reversibility of dewatering (or ‘elasticity’).Several other results and conclusions, of both theoretical and experimental nature, are presented on topics of subsidiary or peripheral interest that are nonetheless important for establishing a reliable basis for research in this area.
This work has proposed links between industrial drinking water coagulation conditions, sludge dewaterability from settling to filtration, and the microstructure of the aggregates making up that sludge. This information can be used when considering the operation or design of a WTP in order to optimise sludge dewaterability, within the constraints of producing drinking water of acceptable quality.
38
Neal, Peter Ross Chemical Sciences & Engineering Faculty of Engineering UNSW. "An examination of the nature of critical flux and membrane fouling by direct observation." Awarded by:University of New South Wales. School of Chemical Sciences and Engineering, 2006. http://handle.unsw.edu.au/1959.4/30584.
Анотація:
Securing water in the right quantities at the right quality for the right price is a major issue around the world. Membranes are making an increasingly important contribution to meeting this need; however their performance is limited by fouling. This thesis reports on an investigation into the fouling of systems related to water treatment using the Direct Observation Through the Membrane (DOTM). The investigation focused on the measurement of critical flux and observation of particle behaviour under a variety of conditions and for a number of different particles. The range of meanings attributed to critical flux in the literature was analysed and several proposals made for the improved use of the concept. In particular, critical flux determination techniques were classified by whether they measure resistance changes or particle deposition; leading to the definition of Critical Resistance and Critical Deposition Fluxes. In this thesis the deposition definition is used exclusively. The effect of Reynolds number and spacer orientation on critical flux was correlated for spacer-filled channels. The heterogeneous deposition patterns observed with regions of heavy deposition next to areas of little or no deposition. This pattern was related to the local hydrodynamics of spacer cells (a few mm2 in size). The correlations developed for critical flux in spacer-filled channels were adjusted for submicron particle size and incorporated into a SpiralWound Module (SWM) leaf model and then used to simulate the fouling of SWM leaves under a range of operating conditions and operating policies. The Mass Balance technique of critical flux determination was also briefly assessed. The applicability of critical flux criteria to SWM arrays was discussed. Fouling, particle behaviour and critical flux were also investigated in air-sparged systems. The post-cleaning water flux was found to be enhanced when the membrane is fouled in the presence of bubbles. The rate of flux decline was reduced by bubbles. Critical flux increased with air flowrate, and decreased with increased liquid flowrate and concentration. Bubbles caused particles to periodically deposit on the membrane. Particles were observed to stream past the membrane under the influence of back-diffusive forces. Video clips of particulate fouling are provided.
39
Domingo, Garth Selby. "UF membranes operated on paper machine wastewater : fouling tendencies and characterisation." Thesis, Stellenbosch : Stellenbosch University, 2001. http://hdl.handle.net/10019.1/52595.
Анотація:
Thesis (MSc)--Stellenbosch University, 2001.ENGLISH ABSTRACT: At the Mondi Kraft paper mill in Piet Retief, paper machine effluent is pre-treated by means of dissolved air flotation (DAF) and a mierostrainer prior to ultrafiltration (UF). Despite the rigorous pre-treatment of the effluent, severe fouling of the UF membranes still persisted, resulting in a sharp decrease in operational flux. In an attempt to improve the flux performance of the UF membranes an investigation was launched into the possible causes of membrane fouling. The study yielded the following results: Ultraviolet-visible (UV-Vis) spectrophotometric analyses of varIOUS effluent samples collected from different locations at the mill indicated the presence of aromatic compounds. Lignosulphonate appeared to be the main constituent in all the samples analysed. UV-Vis spectrophotometry was also performed on fouling extracted from membranes In order to evaluate the different approaches attempted to reduce membrane fouling. Most of the UV-Vis spectra obtained did not show the absorbance maxima below 210 nm that were seen for the paper machine effluent, DAF product, lignosulphonate and mierostrainer product. This indicated that the compounds with absorbance at lower wavelengths did not foul the membranes to the same extent as the aromatic substances with absorbance maxima between 230 and 400 nm. The influence of pH on the absorption of the various effluent samples was also investigated. An increase in pH resulted in (1) a "shift" in the wavelength scans from a lower to a higher wavelength, suggesting ionisation (deprotonation) with a subsequent delocalization of electrons and (2) an increase in the turbidity. The increase in turbidity which accompanied the Increase in pH could be explained by complex formation between the carboxylate ions, phenolic groups and divalent metal ions present in the effluent. Inductively coupled plasma analyses of several effluent samples with pH values 7 and 13 indicated the presence of significant amounts of Ca2+ ions in the effluent. There was a significant decrease in the Ca2+ levels with an increase in pH, which supported the hypothesis that Ca2+ might contribute to complex formation. This resulted in a decrease in solubility and an increase in turbidity. The addition of a chelating agent (ethylenediaminetetra-acetic acid disodium salt) to an effluent solution at pH 13 redissolved the precipitate and considerably reduced the turbidity. The subsequent addition of CaCh again induced precipitation and increased turbidity, confirming the role of Ca2+ in complex formation. Gel permeation chromatographic analyses of mierostrainer product at pH 13 showed the formation of high molecular mass organo-calcium complexes. The exact molecular mass of the complexes present in the mierostrainer product could not be determined by electro spray mass spectrometry because of their poor ionisation ability. Atomic force microscopy and scanning electron microscopy (SEM) showed distinct differences in the membrane surface texture before and after fouling. Furthermore, SEM images of the UF membranes exposed the limited ability of the 30 urn microstrainer, installed downstream from the DAF unit, to remove residual fibres from the DAF product. Static fouling experiments performed on all the flocculants and coagulants used In the paper-making process at the mill showed that none of these substances fouled the UF membranes. Cleaning of the UF membranes with Triton XIOO®, a nOn-IOnIC surfactant, caused a temporary increase in the operating flux to values higher than that of the initial flux. Mechanical cleaning of the UF membrane surface with spongebalIs proved to be one of the most effective and successful methods to prevent flux loss caused by fouling. Pre-coating of the UF membranes with Plutonic" FI08, another non-ionic surfactant, did not promote membrane productivity. Evaluation of various types of membranes indicated that hydrophilic or negatively charged membranes withstood membrane fouling more effectively than hydrophobic UF membranes under the same operating conditions.
AFRIKAANSE OPSOMMING: By Mondi Kraft se papier meule in Piet Retief word afloopwater vanaf die papiermasjiene vir hergebruik met behulp van ultrafiltrasie (UF) behandel. Opgeloste lugflotasie (OLF) en mikrosiwwing word as voorbehandeling vir die UF membraanproses ingespan. Ondanks die intensiewe voorafbehandeling wat toegepas word, vind daar geweldige aanvuiling van die UF membrane plaas wat tot die vinnige verlaging in bedryfsfluks aanleiding gee. 'n Ondersoek na die moontlike oorsake van membraan-aanvuiling het die volgende bevindinge opgelewer: Ultraviolet-sigbare (UV-Vis) spektroskopie van water monsters wat by die meule versamel is, het die teenwoordigheid van aromatiese komponente aangetoon, met lignosulfonaat die hoofkomponent in al die monsters wat ontleed is. Ekstrakte afkomstig van aangevuilde membrane is ook met behulp van UV-Vis-spektroskopie geanaliseer om verskeie benaderings te evalueer om 'n afname in membraan-aanvuiling te bewerkstellig. Die oorgrootte meerderheid spektra het nie die absorpsie maksima onder 210 nm aangetoon wat teenwoordig was in monsters van die papier masjien afloopwater, OLF uitvloeisel, lignosulfonaat en mikrosif produkwater nie. Dit het aangedui dat die komponente wat by laer golflengte absorbeer nie die UF membrane in dieselfde mate aanvuil as daardie komponente wat by hoër golflengtes (tussen 230 en 400 nm) absorbeer nie. Die invloed wat pH op die absorpsie van komponente teenwoordig in die onderskeie afloopwatermonsters het, is ook ondersoek. 'n Toename in pH het bygedra tot (1) 'n verskuiwing in die spektra vanaf 'n lae na 'n hoër golflengte vanweë ionisasie (deprotonering) met gevolglike delokalisasie van elektrone en (2) 'n toename in turbiditeit. Die toename in turbiditeit wat verband hou met die toename in pH was verduidelik aan die hand van kompleksvorming tussen die karboksilaat ione, fenoliese groepe en divalente metaal ione in die afloopwater. Induktief gekoppelde plasma analise van verskeie water monsters by pH 7 en 13 het die teenwoordigheid van 'n groot hoeveelheid Ca2+ aangetoon. 'n Verlaging in die vlakke van opgeloste Ca2+ het met die toename in pH verband gehou. Dit het die moontlike verbintenis tussen Ca2+ en kompleksvorming ondersteun wat bygedra het tot die afname in oplosbaarheid en toename in turbiditeit. Die byvoeging van etileendiamientetra-asynsuur-dinatriumsout, 'n kelerings reagens by afloopwater (pH 13) het die presipitaat weer in oplossing gebring en die turbiditeit merkwaardig verlaag. Die byvoeging van CaCh het weer presipitasie geïnduseer, met 'n gevolglike toename in turbiditeit. Hiermee is Ca2+ se rol in kompleksvorming bevestig. Gelpermeasie-chromatografiese analise van die mikrosif produk (pH 13) het die vorming van hoë molekulêre massa organo-kalsium komplekse bevestig. Dit was egter nie moontlik om met behulp van massaspektrometrie die korrekte molekulêre massa van die komplekse te bepaal nie vanweë hul onvermoë om te ioniseer. Atomiese krag mikroskopie en skandeer elektron mikroskopie (SEM) het duidelik die voor en na verskil getoon wat aanvuiling op die membraantekstuur gehad het. 'n SEM foto van die aangevuilde UF membraan het die onvermoë van die mikrosif blootgelê om oorblywende vesels vanuit die OLF produkwater te verwyder. Resultate bekom gedurende passiewe aanvuilingseksperimente het aangetoon dat al die in-proses flokkulante en koagulante wat gebruik word by die papier meule geen bydrae tot die aanvuiling van die UF membrane maak nie. Skoonmaak van die UF membrane met Triton XIOO® bring 'n verhoging in bedryfsvloed teweeg, maar die verhoging, wat hoër as die oorspronklike vloed is, is kortstondig. Meganiese skoonmaak van die buismembrane met behulp van sponsballe blyk die mees effektiewe skoonmaakmetode te wees. Voorafbehandeling van die UF membrane met Plutonic" F 108 het nie die membraanproduktiwiteit verhoog nie. Daar is ook bevind dat hidrofiliese of negatief gelaaide membrane groter weerstand bied teen aanvuiling in vergelyking met hidrofobiese UF membrane onder dieselfde bedryfstoestande.
40
Cromey, Tyler. "Effect of elevated temperature on ceramic ultrafiltration of colloidal suspensions." Thesis, Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/51778.
Анотація:
The inherent thermal resistance of ceramic membranes allows for treatment of industrial waters at elevated temperatures. Traditionally, the high temperature of wastewater has been an issue compromising the integrity of polymeric membrane systems or requiring the temperature to be lowered for further treatments. In ceramic membrane systems, a decrease in viscosity with increasing temperature, however, can be utilized, which increases the permeate flux. In this study, the fouling of ceramic ultrafiltration by feed solutions containing colloidal silica was evaluated at temperatures between 25 – 90 °C seen in various industries. Ceramic membranes were able to perform well at elevated temperatures up to 90 ºC with sustained mechanical and chemical integrity. Results showed net benefit of filtration at elevated temperatures on permeate flux in spite of increasing total fouling resistance with temperature. When the temperature increased from 25 to 90 °C, there was a 90% increase in steady-state permeate flux. The dominant resistance was physically removable fouling, and the increase in fouling with feed temperature was supported by force balance analyses. This study provides a foundation from which further studies can be developed including pilot-scale testing, use of real wastewater, and the effects of operating conditions.
41
Rossouw, Arnoux. "Modified track-etched membranes using photocatalytic semiconductors for advanced oxidation water treatment processes." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/80276.
Анотація:
Thesis (MScEng)--Stellenbosch University, 2013.ENGLISH ABSTRACT: The purpose of this study was to develop modi ed tract-etched membranes using nanocomposite TiO2 for advanced water treatment processes. Photocatalytic oxidation and reduction reactions take place on TiO2 surfaces under UV light irradiation, therefore sunlight and even normal indoor lighting could be utilised to achieve this effect. In membrane ltration, caking is a major problem, by enhancing the anti-fouling properties of photocatalysts to mineralise organic compounds the membrane life and e ciency can be improved upon. In this study the rst approach in nanocomposite membrane development was to directly modify the surface of polyethylenetherephthalate (PET) track-etched membranes (TMs) with titanium dioxide (TiO2) using inverted cylindrical magnetron sputtering (ICMS) for TiO2 thin lm deposition. The second approach was rst to thermally evaporate silver (Ag) over the entire TM surface, followed by sputtering TiO2 over the silver-coated TM. As a result a noble metal-titania nanocomposite thin lm layer is produced on top of the TM surface with both self-cleaning and superhydrophilic properties. Reactive inverted cylindrical magnetron sputtering is a physical vapour deposition method, where material is separated from a target using high energy ions and then re-assimilated on a substrate to grow thin lms. Argon gas is introduced simultaneously into the deposition chamber along with O2 (the reactive gas) to form TiO2. The photocatalytic activity and other lm properties, such as crystallinity can be in uenced by changing the sputtering power, chamber pressure, target-to-substrate distance, substrate temperature, sputtering gas composition and ow rate. These characteristics make sputtering the perfect tool for the preparation of di erent kinds of TiO2 lms and nanostructures for photocatalysis. In this work, the utilisation of ICMS to prepare photocatalytic TiO2 thin lms deposited on track-etched membranes was studied in detail with emphasis on bandgap reduction and TM surface regeneration. Nanostructured TiO2 photocatalysts were prepared through template directed deposition on track-etched membrane substrates by exploiting the good qualities of ICMS. The TiO2-TM as well as Ag-TiO2-TM thin lms were thoroughly characterised. ICMS prepared TiO2 lms were shown to exhibit good photocatalytic activities. However, the nanocomposite Ag-TiO2 thin lms were identi ed to be a much better choice than TiO2 thin lms on their own. Finally a clear enhancement in the photocatalytic activity was achieved by forming the Ag-TiO2 nanocomposite TMs. This was evident from the band-gap improvement from 3.05 eV of the TiO2 thin lms to the 2.76 eV of the Ag-TiO2 thin lms as well as the superior surface regenerative properties of the Ag-TiO2-TMs.
AFRIKAANSE OPSOMMING: Die doel van hierdie studie was om verbeterde baan-ge etste membrane (BMe) met behulp van nano-saamgestelde titaandioksied (TiO2) vir gevorderde water behandeling prosesse te ontwikkel. Fotokatalitiese oksidasie- en reduksie reaksies vind plaas op die TiO2 oppervlaktes onder UV-lig bestraling, en dus kan sonlig en selfs gewone binnenshuise beligting gebruik word om die gewenste uitwerking te verkry. In membraan ltrasie is die aanpaksel van onsuiwerhede 'n groot probleem, maar die verbetering van die self-reinigende eienskappe van fotokatalisators deur organiese verbindings te mineraliseer, kan die membraan se leeftyd en doeltre endheid verbeter word. In hierdie studie was die eerste benadering om nano-saamgestelde membraan ontwikkeling direk te verander deur die oppervlak van polyethylenetherephthalate (PET) BMe met 'n dun lagie TiO2 te bedek, met behulp van reaktiewe omgekeerde silindriese magnetron verstuiwing (OSMV).Die tweede benadering was eers om silwer (Ag) termies te verdamp oor die hele BM oppervlak, gevolg deur TiO2 verstuiwing bo-oor die silwer bedekte BM. As gevolg hiervan is 'n edelmetaal-titanium nano-saamgestelde dun lm laag gevorm bo-op die oppervlak van die BM, met beide self-reinigende en verhoogde hidro liese eienskappe. OSMV is 'n siese damp neerslag metode, waar materiaal van 'n teiken, met behulp van ho e-energie-ione, geskei word, en dan weer opgeneem word op 'n substraat om dun lms te vorm. Argon gas word gelyktydig in die neerslag kamer, saam met O2 (die reaktiewe gas), vrygestel om TiO2 te vorm. Die fotokatalitiese aktiwiteit en ander lm eienskappe, soos kristalliniteit, kan be nvloed word deur die verandering van byvoorbeeld die verstuiwingskrag, die druk in die reaksiekamer, teiken-tot-substraat afstand, substraattemperatuur, verstuiwing gassamestelling en vloeitempo. Hierdie eienskappe maak verstuiwing die ideale hulpmiddel vir die voorbereiding van die verskillende soorte TiO2 lms en nanostrukture vir fotokatalisasie. In hierdie tesis word OSMV gebruik ter voorbereiding van fotokatalitiese TiO2 dun lms, wat gedeponeer is op BMe. Hierdie lms word dan in diepte bestudeer, met die klem op bandgaping vermindering en BM oppervlak hergenerasie. Nanogestruktureerde TiO2 fotokataliste is voorberei deur middel van sjabloongerigte neerslag op BM substrate deur die ontginning van die goeie eienskappe van OSMV. Die TiO2-BM dun lms, sowel as Ag-TiO2-BM dun lms, is deeglik gekarakteriseer. OSMV voorbereide TiO2 dun lms toon goeie fotokatalitiese aktiwiteite. Nano-saamgestelde Ag-TiO2 dun lms is egter ge denti seer as 'n veel beter keuse as TiO2 dun lms. Ten slotte is 'n duidelike verbetering in die fotokatalitiese aktiwiteit bereik deur die vorming van die Ag-TiO2 nano-saamgestelde BMe. Dit was duidelik uit die bandgapingverbetering van 3,05 eV van TiO2 dun lms in vergelyking met die 2,76 eV van Ag-TiO2 dun lms. 'n Duidelike verbetering is behaal in die fotokatalitiese aktiwiteit deur die vorming van die Ag-TiO2 nano-saamgestelde TMs.
42
Carvalho, Maiara Soares de. "Aplicação da Moringa oleifera na remoção de células de Microcystis aeruginosa e metabólitos por flotação por ar dissolvido e filtração rápida." Universidade Tecnológica Federal do Paraná, 2015. http://repositorio.utfpr.edu.br/jspui/handle/1/1197.
Анотація:
CNPqFlorações de cianobactérias em reservatórios de abastecimento de água têm ocorrido com uma frequência cada vez maior, causando diversos problemas de ordem operacional nos sistemas de tratamento de água em decorrência da elevada densidade de células, além de preocupações quanto à eficiência do tratamento na remoção de metabólitos como cianotoxinas e compostos odoríferos. Este trabalho teve por objetivo avaliar a aplicabilidade da Moringa oleifera Lam pura e associada ao policloreto de alumínio (PACl) na remoção de células de Microcystis aeruginosa, microcistinas, 2-MIB e geosmina por meio de flotação por ar dissolvido e filtração rápida, utilizando carvão ativado granular. Primeiramente, os sais NaCl e CaCl2 foram avaliados para a extração do coagulante de M. oleifera. As amostras consistiram em água sintética adicionada de ácido húmico e células de M. aeruginosa para valores iniciais de 25 uT. O coagulante obtido com 1M CaCl2 de M. oleifera apresentou maior eficiência de remoção de cor, turbidez e número de células, sendo, para ele, indicada como ideal a dose de 50 mg L-1. É indicado que o CaCl2 não permite uma maior eficiência de extração do coagulante, mas sim que participe na formação dos flocos. A partir desses resultados, considerou-se a substituição de 10 a 50% do coagulante salino por PACl. O conjunto de coagulantes em proporções de 70:30 e 60:40 de M. oleifera e PACl permitiram uma melhoria na eficiência de remoção de células e redução do carbono orgânico residual. Finalmente, para essas proporções, foi avaliada a contribuição do uso de carvão ativado granular (CAG) como camada intermediária de filtro de areia visando à remoção de microcistinas, 2-MIB e geosmina. As amostras foram adicionadas de 50 ng L-1 de 2-MIB e geosmina, e 25 μg L-1 de microcistina-LR equivalente, antes dos ensaios. O uso do filtro com camada intermediária de CAG para o conjunto de coagulantes na proporção 70:30 (M.oleifera:PACl) resultou em eficiências globais acima de 95% para a remoção de cor, turbidez, células de M. aeruginosa, microcistinas e geosmina, e de 51 a 75% de remoção de 2-MIB e carbono orgânico dissolvido. Deste modo, o uso de M. oleifera como clarificante de águas com a substituição de 30% por PACl pode reduzir gastos com reagentes por parte de alguns países que hoje importam seu material para clarificação da água, e a adição de CAG no filtro de areia poderia reduzir custos e espaço com a instalação de mais de uma etapa para a remoção de metabólitos. Assim, este conjunto é indicado como uma alternativa de tratamento convencional de água, devido à sua capacidade de remoção de células e metabólitos, além da manutenção de cor, turbidez e microcistinas abaixo dos níveis estipulados para água de consumo.
Nutrient inputs leads to more frequent algal blooms in water supply reservoir which causes operational problems in water treatment plants due to high density of cells, aside from complications induced by its capacity of production of cyanotoxins and taste and odour compounds. The present study had as purpose an evaluation of the applicability of Moringa oleifera Lam as a coagulant with and without polyaluminium chloride (PACl) in the removal of Microcystis aeruginosa cells, microcystins, 2-MIB and geosmin using dissolved air flotation and filtration, using granulated activated carbon (GAC). First, NaCl and CaCl2 salts were studied for extraction of the coagulant. Samples were obtained by the addition of humic acid and M. aeruginosa cells in synthetic water in order to obtain 25 NTU. Coagulant obtained with 1M CaCl2 showed a better performance for color, turbidity and cells removal, being indicated 50 mg L-1 dosage. CaCl2 would not extract better the active component of M. oleifera seeds, but participate on flocs formation. Based on this, PACl addition was evaluated and added in the ranges of 10 to 50% substitution of the saline coagulant. 70:30 and 60:40 proportions of M.oleifera:PACl were indicated in order to to remove turbidity, color and cells. Finally, the use of GAC as an intermediate layer in rapid sand filtration bed was evaluated as a function of microcystins, 2-mib and geosmine retention capacity. Cited proportions were followed by filtration, added of 2-MIB and geosmin 50 ng L-1 as well as 25 μg L-1 of microcystin-LR equivalent before tests. A 70:30 (M.oleifera:PACl) proportion followed by rapid sand filtration combined with GAC led to removal efficiencies above 95% for color, turbidity, M. aeruginosa cells, geosmin and microcystins, and 51 to 75% efficiencies for 2-MIB and dissolved organic carbon. Hence, M. oleifera usage as water coagulant with 30% of PACl can reduce costs for some countries, and the addition of a GAC layer on a sand filter can reduce cost and space in water treatment plants. This process is indicated as an alternative conventional treatment for the removal of cyanobacteria cells and metabolites, besides its capacity to maintain turbidity, color and microcystins below the stipulated levels for water consumption.
43
Roux-de, Balmann Hélène. "Utilisation de l'ultrafiltration dans le traitement de l'eau." Toulouse 3, 1988. http://www.theses.fr/1988TOU30106.
Анотація:
Etude des performances de ce systeme de filtration sur membrane en utilisant des polluants de differentes natures (solutes organiques, particules en suspension) representants ceux contenus dans une eau reelle plus complexe
44
Smith, Ross Andrew. "Biomedical Applications Employing Microfabricated Silicon Nanoporous Membranes." Case Western Reserve University School of Graduate Studies / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=case1278705155.
45
Tonetti, Adriano Luiz 1973. "Pos-tratamento de efluente anaerobio por filtros de areia." [s.n.], 2004. http://repositorio.unicamp.br/jspui/handle/REPOSIP/258247.
Анотація:
Orientador: Bruno Coraucci FilhoDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo
Made available in DSpace on 2018-08-04T21:31:46Z (GMT). No. of bitstreams: 1 Tonetti_AdrianoLuiz_M.pdf: 4911696 bytes, checksum: 17f72ad475f9781c9cc0c2be169415a9 (MD5) Previous issue date: 2004
Resumo: O objetivo deste projeto foi estudar os filtros de areia como um método de baixo custo para o pós-tratamento de filtros anaeróbios alimentados com esgoto sanitário. Nesta pesquisa buscou-se contribuir com o desenvolvimento deste sistema avaliando-se a eficiência de tratamento de quatro filtros de areia com diferentes profundidades de leitos (0,25; 0,50, 0,75 e 1,00 m). A alimentação era proveniente de reatores anaeróbios e foram empregadas cinco cargas diferentes de aplicação (20, 40, 60, 80 e 100 Lm-2). Cada uma delas dispostas diariamente pelo período de um mês. O esgoto bruto, afluente e efluente dos filtros de areia foram analisados semanalmente, permitindo constatar que no emprego de baixas cargas de efluente anaeróbio o sistema propiciava uma remoção superior a 96% da DBO, adequação na emissão de coliformes totais e completa nitrificação. Aumentando-se as cargas, ocorria uma pequena redução da eficiência, no entanto os resultados ainda eram satisfatórios
Abstract: The aim of this project was to study sand filters as a low cost method in the post treatment of upflow anaerobic filter effluent, fed by municipal wastewater. This research intends to contribute with the development of this system estimating the efficiency of the treatment of four sand filters with different depths of the sand layer (0,25; 0,50, 0,75 e 1,00 m). The feed (I think it's influent) was from the four upflow anaerobic filters. Five hydraulic loads (20, 40, 60, 80 e 100 Lm-2) were used to apply the effluent on the sand filters. Each one was applied for one month and later the frequency was increased for two and tree times per day. The municipal wastewater, influent and the effluent of the sand filter were weekly analyzed allowing to conclude that the treatment system had good removal of BOD, COD, TOC, nutrients and microorganisms like total and fecal coli forms. The effluent was good to be disposed or to reused.
Mestrado
Saneamento e Ambiente
Mestre em Engenharia Civil
46
Kanegae, Alexandre Patto. "Remoção de helmintos e protozoarios em sistema de tratamento filtro anaerobio- filtro de areia visando uso agricola." [s.n.], 2005. http://repositorio.unicamp.br/jspui/handle/REPOSIP/258240.
Анотація:
Orientador: Bruno Coraucci FilhoDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo
Made available in DSpace on 2018-08-09T15:44:03Z (GMT). No. of bitstreams: 1 Kanegae_AlexandrePatto_M.pdf: 1125389 bytes, checksum: dc519b3abb15e2a72d094f64448f7383 (MD5) Previous issue date: 2005
Resumo: Este trabalho foi desenvolvido com o intuito de se verificar a utilização de filtros de areia, como um sistema de pós-tratamento de efluentes de filtros anaeróbios na remoção de organismos patogênicos presentes nos esgotos, tais como protozoários e helmintos. Para tanto, foi feita a verificação das melhores taxas de aplicação de efluente de filtro anaeróbio em 4 filtros de areia, com profundidades de 0,25; 0,50; 0,75 e 1,00 m. As taxas de aplicação foram de 20, 40, 60, 80 e 100 Lm-2dia -1. O tempo do experimento foi de Maio de 2003 a Agosto de 2004. Para verificação dos organismos presentes no efluente utilizou-se a metodologia adotada pela Cetesb, descrita pela norma L5.550 (1989) - Hoffman modificado e os resultados foram expressos em número de organismos/L. Os resultados demonstraram que o processo de tratamento biológico ocorrido nos filtros de areia com leito mais profundo (1,00 m) foi o que apresentou melhor performance. Não houve correlação entre o número de organismos encontrados e as taxas aplicadas, mas o valor estipulado pela NBR 7229 (1993) de 100 Lm-2dia-1 de efluente aplicado, apresentou resultados satisfatórios
Abstract: This project was developed with the aim of verifying the use of sand filters as a post treatment system of effluents from anaerobic filters. Most of the pathogens found in the wastewater can be classified as protozoans and helminths. For that, the best application rates of anaerobic effluent were studied in four sand filters. They were 0,25; 0,50; 0,75 and 1,00 m deep. The application rates were 20, 40,60,80 e 100 Lm-2day-1. The experiment was run from May 2003 to August 2004. To verify the presence of the organisms in the wastewater, the methodology adopted by Cetesb was used (described as Standard L5.550, 1989) - Hoffman modified and the results were expressed in number or organisms/L. The results show that the biological process of treatment occurred in the deepest sand filter (1,00 m) was the one which presented the best performance. There was no correlation between the number of microorganisms found and the applied rates but, the value established by NBR 7229 (1993) of 100 Lm-2day-1 of effluent presented satisfactory results
Mestrado
Saneamento e Ambiente
Mestre em Engenharia Civil
47
Kim, Jinkeun 1968. "Physicochemical aspects of particle breakthrough in granular media filtration." 2004. http://hdl.handle.net/2152/12781.
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Kweon, Ji Hyang. "Integrated water treatment softening and ultrafiltration /." Thesis, 2002. http://wwwlib.umi.com/cr/utexas/fullcit?p3108496.
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Abrams, Leonard J. "Family scale rural water treatment plant: intermittent slow sand filtration." Thesis, 2015. http://hdl.handle.net/10539/17521.
50
"Die evaluasie van Suid-Afrikaanse filtermedia vir diepbedfiltrasie." Thesis, 2015. http://hdl.handle.net/10210/14609.
Анотація:
M.Ing.A number of distinctly different local and international media specifications are currently being used in South Africa. Along with some opposing requirements, these specifications all specify different testing procedures to be used in the evaluation of filter media. Furthermore the already confusing situation is being complicated by a lack of knowledge as to the general properties of South African filter media ...