Articoli di riviste: "Iron removal"

1

Matsiyevska, Oksana, Iryna Kachmar e Vladyslav Kapitula. "EFFICIENCY OF IRON REMOVAL FROM DRINKINGWATER WITH HOUSEHOLD FILTERS". Theory and Building Practice 2020, n. 1 (15 giugno 2020): 81–87. http://dx.doi.org/10.23939/jtbp2020.01.081.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

2

Holm, Thomas R., Walton R. Kelly, Steven D. Wilson e Jonathan L. Talbott. "Arsenic removal at llinois iron removal plants". Journal - American Water Works Association 100, n. 9 (settembre 2008): 139–50. http://dx.doi.org/10.1002/j.1551-8833.2008.tb09727.x.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

3

Morosini, Denise Fontoura, Carlos Adolpho Magalhães Baltar e Antonio Carlos Duarte-Coelho. "Iron removal by precipitate flotation". Rem: Revista Escola de Minas 67, n. 2 (giugno 2014): 203–7. http://dx.doi.org/10.1590/s0370-44672014000200012.

Testo completo

Abstract (sommario):

The water from several artesian wells in the metropolitan area of Recife presents high iron content, preventing its use in some industrial processes. The possibility of removing the iron by the use of precipitate flotation using sodium dodecyl sulphate (SDS) as collector was studied. The tests were carried out in a glass column 65 cm high, fed by a constant airflow. At pH 8, where the isoelectric point of colloidal iron hydroxide [Fe(OH)3] was observed, the size of the precipitate increases with conditioning time and facilitates the removal of iron ions by flotation. The results showed that an increase in conditioning time, from 5 to 20 minutes, resulted in a reduction of the residual concentration of iron from 13.2 to 0.2 ppm. The decrease in precipitate specific surface area rendered a decrease in the collector consumption possible. The iron ion removal process by flotation using SDS as collector was shown to be quite efficient. A removal of 99% of Fe3+ contained in the original solution was obtained.

Gli stili APA, Harvard, Vancouver, ISO e altri

4

Tong, Dongli, Jie Zhuang e Xijuan Chen. "Reactive Transport and Removal of Nutrients and Pesticides in Engineered Porous Media". Water 11, n. 7 (26 giugno 2019): 1316. http://dx.doi.org/10.3390/w11071316.

Testo completo

Abstract (sommario):

Agricultural nonpoint pollution has been recognized as a primary source of nutrients and pesticides that contaminate surface water and groundwater. Reactive materials have great potential to remove nutrients and pesticides from agricultural drainage water. In this study, we investigated the reactive transport and removal of coexisting nitrate, phosphate, and three pesticides (tricyclazole, isoprothiolane, and malathion) by iron filings and natural ore limestone through column experiments under saturated flow conditions. Breakthrough results showed that 45.0% and 35.8% of nitrate were removed by iron filings and limestone during transport, with average removal capacities of 2670 mg/kg and 1400 mg/kg, respectively. The removal of nitrate was mainly due to microbial denitrification especially after 131–154 pore volumes (≈30 d), whereas reduction to ammonia dominated nitrate removal in iron filings during early phase (i.e., <21.7 d). The results showed that 68.2% and 17.6% of phosphate were removed by iron filings and limestone, with average removal capacities of 416.1 mg/kg and 155.2 mg/kg, respectively. Mineral surface analyses using X-ray diffraction (XRD) and scanning electron microscope (SEM) coupled with energy-dispersive X-ray analysis (EDX) suggested that ligand exchange, chemical precipitation, and electrostatic attraction were responsible for phosphate removal. Chemical sorption was the main mechanism that caused removals of 91.6–100% of malathion and ≈27% of isoprothiolane in iron filings and limestone. However, only 22.0% and 1.1% of tricycalzole were removed by iron filings and limestone, respectively, suggesting that the removal might be relevant to the nonpolarity of tricyclazole. This study demonstrates the great potential of industrial wastes for concurrent removal of nutrients and pesticides under flow conditions.

Gli stili APA, Harvard, Vancouver, ISO e altri

5

Munter, Rein, Heldi Ojaste e Johannes Sutt. "Complexed Iron Removal from Groundwater". Journal of Environmental Engineering 131, n. 7 (luglio 2005): 1014–20. http://dx.doi.org/10.1061/(asce)0733-9372(2005)131:7(1014).

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

6

Jalili, Zahra, Ataallah Bahrami, Masoud Ghadri, Behzad Nemati Akhgar e Fatemeh Kazemi. "Leaching for iron removal from low-grade bauxite ore to access refractory instruction". Rudarsko-geološko-naftni zbornik 37, n. 1 (2022): 55–64. http://dx.doi.org/10.17794/rgn.2022.1.6.

Testo completo

Abstract (sommario):

Iron-bearing minerals are the most important interfering compounds that are found with bauxite reserves. The element iron has adverse effects on bauxite applications, including the use of bauxite in refractory soils. The purpose of this research is to investigate the possibility of iron removal from low-grade bauxite ores to utilize them in refractory industries. For achieving this purpose, iron removal tests were performed on bauxite samples with an alumina to silica modulus of 0.73. After determining the appropriate iron removal method among the magnetic separation, calcination, and leaching (with H2SO4 and HCl) processes, optimal separation conditions were determined by tests that were designed using the Taguchi method. According to leaching results, using HCl for raw feed (un-calcined) provided the best result for iron removal. During this test, Fe2O3 grade decreased from 5.14% to 0.08%, and the alumina to silica modulus increased to 0.75. Calcination of the concentrate obtained from this test has led to favorable results in reducing the Fe2O3 grade (0.04%) and increasing the Al2O3 grade. Afterwards, in tests designed by the Taguchi method, the effect of parameters such as time, process temperature, HCl concentration, and feed grain size on iron removal from bauxite by HCl leaching processes are discussed. According to the results, the best efficiency of iron removal for a feed grain size of 250 µm is achieved in the following conditions: 30% HCl, process temperature of 25°C, and process time of 120 minutes. In this case, iron removal efficiency and Fe2O3 grade in process concentrate are 92.78% and 0.56%, respectively.

Gli stili APA, Harvard, Vancouver, ISO e altri

7

Viswanathan, M. N., e B. Boettcher. "Biological Removal of Iron from Groundwater". Water Science and Technology 23, n. 7-9 (1 aprile 1991): 1437–46. http://dx.doi.org/10.2166/wst.1991.0596.

Testo completo

Abstract (sommario):

Host of the soluble iron in groundwater exists in complexes with organic matter. Removal of iron, complexed with organic matter, is difficult and requires the use of a strong oxidant such as ozone, chlorine, etc. This increases capital and operating costs of water treatment plants. Iron oxidizing bacteria like Gallionellaferruginea are known to oxidize iron and derive the energy for the reduction of CO2. A biological reactor was developed, based on these principles, to remove iron from groundwater. The reactor was successful in reducing iron levels in groundwater from 2.5-3.0 mg/l to about 0.1 mg/l. It was observed that, apart from Gallionellaferruginea, Sphaerotilus spp. were also present in the reactor column. No major problems with respect to clogging of filters or the reactor column were experienced.

Gli stili APA, Harvard, Vancouver, ISO e altri

8

M, Takahashi. "Arsenic Removal Using a Simple Oxidation Device". Open Access Journal of Waste Management & Xenobiotics 4, n. 1 (26 gennaio 2021): 1–4. http://dx.doi.org/10.23880/oajwx-16000158.

Testo completo

Abstract (sommario):

Arsenic exists widely in the environment, and a lot of arsenic pollution is found in the groundwater of South East Asia. In order to make arsenic free water, we made a simple device. The device is mainly composed of an iron containing oxidation tank, settling tank and sand filter. The arsenic in the water can be removed by iron oxidation which is caused by aeration. The device can remove about 98% of the arsenic in the water using less energy, and be maintenance free for a long period.

Gli stili APA, Harvard, Vancouver, ISO e altri

9

Mamun, Muhammad Rashed Al, e Shuichi Torii. "Removal of Hydrogen Sulfide (H2S) from Biogas Using Zero-Valent Iron". Journal of Clean Energy Technologies 3, n. 6 (2015): 428–32. http://dx.doi.org/10.7763/jocet.2015.v3.236.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

10

Wang, Zi, Zhe Chen, Hong Wu Wang e Lu Ming Ma. "Effect of Placement Pattern and Quantity of Iron Shavings in Reactor on Biological Nutrient Removal from Domestic Wastewater". Applied Mechanics and Materials 164 (aprile 2012): 186–89. http://dx.doi.org/10.4028/www.scientific.net/amm.164.186.

Testo completo

Abstract (sommario):

Effect of placement pattern and quantity of iron shavings in reactor on biological nutrient Removal from domestic wastewater was conducted. The results indicate that: different placement pattern had obvious effect on TP removal, but had no distinct effect on TN removal; when iron was placed beside aerator, the highest TP removal can be obtained. Adding more iron can just slightly enhance TP and TN removal when iron shaving quantity increased from 5 g to 20 g per 900 ml wastewater; iron adding restrained transfer of ammonia to nitrate by microbe and this defect should be overcome in practice; 5 g iron per 900 mL is the best choice to balance good nutrient removal and low cost.

Gli stili APA, Harvard, Vancouver, ISO e altri

11

Podder, Prasenjit, Zongliang Zhang, Rick Q. Honaker, Michael L. Free e Prashant K. Sarswat. "Evaluating and Enhancing Iron Removal via Filterable Iron Precipitates Formation during Coal-Waste Bioleaching". Eng 2, n. 4 (8 dicembre 2021): 632–42. http://dx.doi.org/10.3390/eng2040040.

Testo completo

Abstract (sommario):

Iron removal via jarosite precipitate formation is a commonly used technique in various hydrometallurgical processes. Excess iron removal often becomes essential to an overall metal recovery circuit. This is particularly important to processes involving iron-bearing minerals. A technique, which involved the use of pyrite to generate acid for leaching, for iron removal is critical to enabling the process. Iron removal using CaO or similar reagents is expensive and often results in lost product. In the present study, various compounds that facilitate jarosite formation, namely Na2SO4, NH4OH, KCl, and KOH, were utilized and their effect in precipitation was observed. Visual Minteq assisted simulations were run in order to evaluate favorable conditions for iron removal. Morphology and elemental composition of precipitates were analyzed using scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy, and the phase purity was identified using X-ray diffraction analysis.

Gli stili APA, Harvard, Vancouver, ISO e altri

12

Pramanik, Biplob Kumar, Sagor Kumar Pramanik e Fatihah Suja. "Removal of arsenic and iron removal from drinking water using coagulation and biological treatment". Journal of Water and Health 14, n. 1 (29 settembre 2015): 90–96. http://dx.doi.org/10.2166/wh.2015.159.

Testo completo

Abstract (sommario):

Effects of biological activated carbon (BAC), biological aerated filter (BAF), alum coagulation and Moringa oleifera coagulation were investigated to remove iron and arsenic contaminants from drinking water. At an initial dose of 5 mg/L, the removal efficiency for arsenic and iron was 63% and 58% respectively using alum, and 47% and 41% respectively using Moringa oleifera. The removal of both contaminants increased with the increase in coagulant dose and decrease in pH. Biological processes were more effective in removing these contaminants than coagulation. Compared to BAF, BAC gave greater removal of both arsenic and iron, removing 85% and 74%, respectively. Longer contact time for both processes could reduce the greater concentration of arsenic and iron contaminants. The addition of coagulation (at 5 mg/L dosage) and a biological process (with 15 or 60 min contact time) could significantly increase removal efficiency, and the maximum removal was observed for the combination of alum and BAC treatment (60 min contact time), with 100% and 98.56% for arsenic and iron respectively. The reduction efficiency of arsenic and iron reduced with the increase in the concentration of dissolved organics in the feedwater due to the adsorption competition between organic molecules and heavy metals.

Gli stili APA, Harvard, Vancouver, ISO e altri

13

Martynov, Serhii, Victor Fylypchuk, Vitalii Zoshchuk, Serhii Kunytskyi, Andrii Safonyk e Oleg Pinchuk. "Technological model of water contact iron removal". Journal of Water and Land Development 39, n. 1 (1 dicembre 2018): 93–99. http://dx.doi.org/10.2478/jwld-2018-0063.

Testo completo

Abstract (sommario):

AbstractDifferent types of filters are used to remove iron from underground water, one of them is foam polystyrene. Depending on the chemical water composition, tasks for water supply and other working conditions of iron-removing filters, it is necessary to define an exact grain size, specific granulometric composition, the thickness of the layer and the adequate rate of filtration. This kind of problems is multifactorial and its solution is based on the mathematical modelling.As a rule, two parallel processes considered during iron removal of underground water in filters: efficiency of water treatment and growth of head losses. Therefore, the model of water iron removal based on two main blocks, clarifying block takes into account the material balance and kinetics of the process; hydrodynamic block describes the dynamics of head loss in the granular loading. The kinetics of the detention of iron compounds in granular loading consists of two mutually opposite processes. With an increase of the amount of adsorption-catalytic precipitate, the rate of sorption of iron compounds and oxidation of ferric iron increases and the efficiency of iron-removing increases. On the other hand, with decreasing porosity of loading the true velocity of the fluid increases, that reduces the intensity of adhesion of iron compounds.Developed mathematical model allows for determining optimal values of structural and technological parameters of iron-removing filters taking into consideration the specific filtering conditions.

Gli stili APA, Harvard, Vancouver, ISO e altri

14

Zhang, Jin Hua, Hai Qing Zheng, Fang Jiang, Kai Rong Cheng, Xin Jiang, Xiang Long Li e Yi Lin. "Comparison of Removal of 2,4-DNT by Reduction Using Various Iron-Based Materials". Advanced Materials Research 391-392 (dicembre 2011): 303–7. http://dx.doi.org/10.4028/www.scientific.net/amr.391-392.303.

Testo completo

Abstract (sommario):

The reductive degradation of 2,4-dinitrotoluene (2,4-DNT) by three kinds of iron-based materials, namely, copper-doped iron, scrap iron and iron powder, was investigated in detail. The effects of iron materials, pH and iron dosage on the removal efficiency were studied. The results indicated that copper-doped iron had the highest removal rate of 2,4-DNT. The removal rate of 2,4-DNT increased with increasing temperature. After addition of sodium sulfate, the removal rate of 2,4-DNT was enhanced. According to GC/MS analyses, 2,4-diaminotoluene was the final product of 2,4-DNT and possible reductive pathway of 2,4-DNT was proposed.

Gli stili APA, Harvard, Vancouver, ISO e altri

15

Tang, Yu Lan, Wei Bin Wu, Ya Ting He, Jin Xiang Fu e Xiao Lan Wang. "Low-Temperature Domestication of an Iron and Manganese Oxidizing Bacteria". Advanced Materials Research 374-377 (ottobre 2011): 826–30. http://dx.doi.org/10.4028/www.scientific.net/amr.374-377.826.

Testo completo

Abstract (sommario):

Abstract.One superior iron and manganese bacteria were separated from the stable operation of porcelain granular BAF filters of removing iron, manganese and ammonia. The bacteria was domesticated at low temperature. By analyzing the sample water containing iron and manganese in the role of iron and manganese bacteria which was not domesticated and domesticated at different temperature, observing the Iron and manganese concentration with time going on, studying the bacteria’s removal of iron and manganese property and the domesticated effect. Studies show that: the selected bacteria with 1% bacterial liquid at proper temperature within 48h ,the removal rate of iron and manganese was 75% and 35% respectively;After domesticated at low temperature, the removal rate of the iron and manganese domesticated bacteria at 10°C was improved 0.4 and 2 times more than the before domesticated; The iron and manganese domesticated bacteria at 10°C did not grow at 4°C,but the bacteria’s removal rate was better than the bacteria cultured at 30°C,and the iron removal rate was improved from 23% to 35%,the manganese removal rate was improved from 5% to 11%.

Gli stili APA, Harvard, Vancouver, ISO e altri

16

Singh, Tony Sarvinder, e Kamal K. Pant. "Kinetics and Mass Transfer Studies on the Adsorption of Arsenic onto Activated Alumina and Iron Oxide Impregnated Activated Alumina". Water Quality Research Journal 41, n. 2 (1 maggio 2006): 147–56. http://dx.doi.org/10.2166/wqrj.2006.017.

Testo completo

Abstract (sommario):

Abstract The present investigation deals with the uptake of As(III) and As(V) ions from aqueous solution by activated alumina and a new laboratory-prepared sorbent—iron oxide impregnated activated alumina. Iron oxide impregnation onto activated alumina significantly increased the percent arsenic removal and adsorption capacity for As(III) and As(V) ions. The maximum As(III) and As(V) removals were 96.8% and 98.4%, respectively, by iron oxide impregnated activated alumina (IOIAA). Maximum As(III) and As(V) removal of 94.2% and 96.1% was observed over activated alumina. Kinetic studies were performed at different initial sorbate concentrations to determine the mechanism of mass transfer of sorbate onto this sorbent. The maximum removal of As(III) and As(V) by activated alumina and iron oxide impregnated alumina takes place within 6 h and attains equilibrium within 12 h. First-order Lagergren kinetics explained the adsorption of arsenic over activated alumina whereas a pseudo-second order rate equation explained the behaviour of As(III) adsorption over iron oxide impregnated activated alumina. Diffusional effects in solid pellets were also investigated to understand the mechanism of adsorption. These results indicate that the mechanism of arsenic adsorption is complex on both sorbents as both pore diffusion and surface diffusion contribute to the arsenic removal. During the initial period, surface diffusion was predominant but as the adsorption progresses, pore diffusion dominated the rate of adsorption.

Gli stili APA, Harvard, Vancouver, ISO e altri

17

Wang, Jian Jun, Li Zhong Chang e Li Zhou. "Research on Reduction Dearsenication in Molten Iron (Steel)". Advanced Materials Research 476-478 (febbraio 2012): 273–80. http://dx.doi.org/10.4028/www.scientific.net/amr.476-478.273.

Testo completo

Abstract (sommario):

The influence of different dearsenization agents on the arsenic removal in molten iron (steel) was studied. The result indicates that low temperature is beneficial to the process of arsenic removal reaction and the different dearsenication agents have different arsenic removal effects on arsenic containing molten iron . However, The dearsenication additive selected has a merely maximum arsenic removal rate of 58.6% while other dearsenic agents have the arsenic removal rate no higher than 25%. Relevant researches also indicate the phosphorus contained in the molten iron has a relatively significant influence on the arsenic removal rate. With the reduction of the content of phosphorus in the molten iron, the arsenic removal rate is improved significantly.

Gli stili APA, Harvard, Vancouver, ISO e altri

18

Lytle, D. A., T. J. Sorg e V. L. Snoeyink. "Optimizing arsenic removal during iron removal: Theoretical and practical considerations". Journal of Water Supply: Research and Technology-Aqua 54, n. 8 (dicembre 2005): 545–60. http://dx.doi.org/10.2166/aqua.2005.0048.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

19

Lehimas, G. F. D., J. I. Chapman e F. P. Bourgine. "Arsenic Removal from Groundwater in Conjunction with Biological-Iron Removal". Water and Environment Journal 15, n. 3 (luglio 2001): 190–92. http://dx.doi.org/10.1111/j.1747-6593.2001.tb00331.x.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

20

Sepehri, S., M. Heidarpour e J. Abedi-Koupai. "Nitrate removal from aqueous solution using natural zeolite-supported zero-valent iron nanoparticles". Soil and Water Research 9, No. 4 (10 novembre 2014): 224–32. http://dx.doi.org/10.17221/11/2014-swr.

Testo completo

Abstract (sommario):

A report on the synthesis and characterization of nanoscale zero-valent iron in the presence of natural zeolite as a stabilizer is presented. This novel adsorbent (Ze-nZVI) was synthesized by the sodium borohydride reduction method. The scanning electron microscopy (SEM) images revealed that the stabilized nZVI particles were uniformly dispersed across the zeolite surface without obvious aggregation. The synthesized Ze-nZVI material was then tested for the removal of nitrate from aqueous solution. The effect of various parameters on the removal process, such as initial concentration of nitrate, contact time, initial pH, and Ze-nZVI dosage, was studied. Batch experiments revealed that the supported nZVI materials generally have great flexibility and high activity for nitrate removal from aqueous solution. The nitrogen mass balance calculation showed that ammonium was the major product of nitrate reduction by Ze-nZVI (more than 84% of the nitrate reduced); subsequently the natural zeolite in Ze-nZVI removed it completely via adsorption. The kinetic experiments indicated that the removal of nitrate followed the pseudo-second-order kinetic model. The removal efficiency for nitrate decreased continuously with an increase in the initial solution pH value and Ze-nZVI dosage but increased with the increase in the initial concentration of nitrate. The overall results indicated the potential efficacy of Ze-nZVI for environmental remediation application.

Gli stili APA, Harvard, Vancouver, ISO e altri

21

Sharma, S. K., B. Petrusevski, A. Jonoski, G. F. Ijpelaar e J. C. Schippers. "Decision support system for optimisation of iron removal from groundwater". Water Supply 2, n. 5-6 (1 dicembre 2002): 257–63. http://dx.doi.org/10.2166/ws.2002.0177.

Testo completo

Abstract (sommario):

Floc filtration and adsorptive filtration are the two main physicochemical mechanisms of iron removal in filters. Under the commonly applied treatment conditions in iron removal plants, the floc filtration is commonly believed to be the dominant mechanism and the adsorptive filtration complimentary. Iron removal filters with iron oxide coated sand are expected to perform better in terms of filtrate quality, filter run time and costs, by switching the mode of operation from predominantly floc filtration to predominantly adsorptive filtration. A decision support system (DSS) is being developed to assess the applicability and to quantify the possible benefits associated with adsorptive iron removal for a given groundwater and a specific plant. This paper introduces the different independent and interconnected modules of the DSS and elaborates on one particular sub-module for the analysis of the extent of floc filtration and adsorptive filtration iron removal in a groundwater treatment plant under given conditions. This computer model would be helpful in optimising the plant performance under the existing mode of operation, formulating strategies for switching from floc filtration to adsorptive filtration, and designing new iron removal plants. Sensitivity analysis showed that pH, iron oxidation rate constant and pre-oxidation time (a function of depth of supernatant and filtration rate) are the main parameters determining the extent of floc filtration and adsorptive iron removal under given conditions. Predominantly adsorptive iron removal in filters can be achieved by reducing the depth of supernatant, increasing the rate of filtration and/or controlling the oxygen concentration in the feed water.

Gli stili APA, Harvard, Vancouver, ISO e altri

22

Veregina, E. L., T. B. Efremenko, L. S. Surodeeva e E. O. Schibro. "The research on iron removal filters". Izvestiya MGTU MAMI 6, n. 2-4 (20 dicembre 2012): 116–21. http://dx.doi.org/10.17816/2074-0530-68348.

Testo completo

Abstract (sommario):

The purpose of this research was the selection of the optimal filtering medium for pressure removal of dissolved iron filters of water conditioning plant. The increase of plant capacity by raising the filtration rate leads to the increase in the pressure drop and reduction the duration of filtration cycle. The aforesaid issue was the cause of studying alternative filtering medium of quartz sand.

Gli stili APA, Harvard, Vancouver, ISO e altri

23

van Halem, D., D. H. Moed, J. Q. J. C. Verberk, G. L. Amy e J. C. van Dijk. "Cation exchange during subsurface iron removal". Water Research 46, n. 2 (febbraio 2012): 307–15. http://dx.doi.org/10.1016/j.watres.2011.10.015.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

24

Zhu, Bintuan, Dennis A. Clifford e Shankar Chellam. "Virus removal by iron coagulation–microfiltration". Water Research 39, n. 20 (dicembre 2005): 5153–61. http://dx.doi.org/10.1016/j.watres.2005.09.035.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

25

Buliauskaitė, Raimonda, Philipp Wilfert, Prashanth Suresh Kumar, Weren W. J. M. de Vet, Geert-Jan Witkamp, Leon Korving e Mark C. M. van Loosdrecht. "Biogenic iron oxides for phosphate removal". Environmental Technology 41, n. 2 (13 luglio 2018): 260–66. http://dx.doi.org/10.1080/09593330.2018.1496147.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

26

Mishima, I., M. Hama, Y. Tabata e J. Nakajima. "Long-term investigation of phosphorus removal by iron electrocoagulation in small-scale wastewater treatment plants". Water Science and Technology 78, n. 6 (17 settembre 2018): 1304–11. http://dx.doi.org/10.2166/wst.2018.402.

Testo completo

Abstract (sommario):

Abstract Small-scale wastewater treatment plants (SWTPs), called Johkasou, are widely used as decentralized and individual wastewater treatment systems in sparsely populated areas in Japan. Even in SWTPs, nutrients should be removed to control eutrophication. An iron electrolysis method is effective to remove phosphorus chemically in SWTPs. However, it is necessary to determine the precise conditions under which phosphorus can be effectively and stably removed in full scale SWTPs for a long period. Therefore, long-term phosphorus removal from SWTPs was investigated and optimum operational conditions for phosphorus removal by iron electrolysis were analyzed in this study. Efficient phosphorus removal can be achieved for a long time by adjusting the amount of iron against the actual population equivalent. The change of the recirculation ratio had no negative effect on overall phosphorus removal. Phosphorus release to the bulk phase was prevented by the accumulated iron, which was supplied by iron electrolysis, resulting in stable phosphorus removal. The effect of environmental load reduction due to phosphorus removal by iron electrolysis was greater than the cost of power consumption for iron electrolysis.

Gli stili APA, Harvard, Vancouver, ISO e altri

27

Sharma, S. K., B. Petrusevski e J. C. Schippers. "Characterisation of coated sand from iron removal plants". Water Supply 2, n. 2 (1 aprile 2002): 247–57. http://dx.doi.org/10.2166/ws.2002.0070.

Testo completo

Abstract (sommario):

Water treatment plants removing iron from groundwater are commonly expected to operate in oxidation-floc formation mode. However, there are indications that adsorptive iron removal plays a role as well. Adsorptive iron removal has several potential advantages over oxidation-floc formation iron removal. Therefore, the physical and surface chemical characteristics of coated sand from twelve different groundwater treatment plants in the Netherlands were analysed to assess their potential use in adsorptive iron removal. Specific surface areas, amounts of iron, manganese, calcium and TOC in the coatings and iron(II) adsorption capacities of the coated media were measured. Additionally, grain size distribution and density of the media were determined and X-ray diffractograms, scanning electron micrographs and EDAX spectra were prepared. Compared to new sand, coated sand had a very high porosity and a very large specific surface area. The surface extractable iron content of the coated sand increased with iron loading. The iron content of the coatings ranged from 27% to 45%. At pH 6.5, the iron(II) adsorption capacities of different coated sands were 10 to 55 times that of new sand. In general, iron(II) adsorption capacities of the coated sand from different plants increased with the increase in the time in use and the iron content of the coating. However, the average annual increase of iron content of the coatings and the iron adsorption capacity were different for the coated sands from different plants, probably due to the difference in water quality, process conditions applied and time in use. The grain size of the filter sand increased and their density decreased with the development of the coating. The decrease in density was a function of the increase in the effective grain size. EDAX analysis showed that iron and oxygen were the main elements in the coating followed by manganese, calcium, silicon and carbon. All the coatings analysed were X-ray amorphous or poorly crystalline. The measured high adsorption capacities of coated sand from wet filters and dry filters of full-scale groundwater treatment plants indicate that, in wet filters, adsorptive iron removal also plays a role. In dry filters, this mechanism should be dominant due to a very short pre-oxidation time. Process efficiencies of wet filters with iron oxide coated sand can be further improved by operating the filters predominantly in the adsorptive filtration mode.

Gli stili APA, Harvard, Vancouver, ISO e altri

28

Mishima, I., M. Hama, Y. Tabata e J. Nakajima. "Improvement of phosphorus removal by calcium addition in the iron electrocoagulation process". Water Science and Technology 76, n. 4 (16 maggio 2017): 920–27. http://dx.doi.org/10.2166/wst.2017.256.

Testo completo

Abstract (sommario):

Small-scale wastewater treatment plants (SWTPs) are widely used as decentralized wastewater treatment systems in sparsely populated areas of Japan. Iron electrolysis, an electrocoagulation technology, is installed in these SWTPs for phosphorus removal. Phosphorus can be removed via the formation of an insoluble compound containing phosphate and iron, such as FePO4; however, it was necessary to determine the conditions under which phosphorus can be effectively and stably removed in actual SWTPs. According to previous studies using iron compounds, improved phosphorus removal was obtained by Ca addition. It is therefore thought that calcium addition may also be effective in improving the phosphorus removal during iron electrolysis in SWTPs. It is also important to determine the chemical state of iron to understand the phosphorus removal mechanism during iron electrolysis. In this study, laboratory-scale batch experiments with the iron electrolysis method were conducted to investigate the effect of phosphorus removal using treated wastewater from actual SWTPs without or with Ca addition. The results indicated that the addition of Ca improved the phosphorus removal performance. Furthermore, phosphorus removal was inhibited in the presence of high dissolved organic carbon (DOC). The X-ray absorption fine structure measurements of the produced particulates in the experiments showed no substantial change in the chemical state of iron without or with Ca addition. The statistical analyses revealed the range of improving or inhibiting effects on phosphorus removal due to the Ca and DOC. Thus, the results of this study provided useful information pertaining to the influence of coexisting substances on phosphorus removal and the chemical state of iron in the produced particulates.

Gli stili APA, Harvard, Vancouver, ISO e altri

29

Ghauch, Antoine, Habib Baydoun, Al Muthanna Tuqan, Ghada Ayoub e Sahar Naim. "Submicrometric Iron Particles for the Removal of Pharmaceuticals from Water: Application to b-Lactam Antibiotics". Advanced Materials Research 324 (agosto 2011): 485–88. http://dx.doi.org/10.4028/www.scientific.net/amr.324.485.

Testo completo

Abstract (sommario):

Sub-micrometric iron particles (Fe0) and amended Fe0 (Cu0Fe0) were tested for the aqueous removal of b-lactam antibiotics. Comparative batch experiments were performed separately on aqueous solutions of dicloxacillin (DCX), cloxacillin (CLX) and oxacillin (OXA). Three different initial concentrations (1, 5 and 10 mg L-1) and four different iron loads (r = 10, 20, 40 and 53 g L-1) were tested. Furthermore, two different mixing regimes were tested: (i) non-disturbed conditions, and (ii) vortex mixing. This experimental design enabled the confirmation of the crucial role of in-situ formed iron corrosion products (Fe oxides) on the removal process. The dynamic process of Fe oxides formation induces adsorption and enmeshment (sequestration or co-precipitation) of dissolved antibiotics. Results clearly delineated the superiority of Cu0Fe0 bimetallics compared to Fe0. For example, after 4 h of contact with iron particles at r = 40 g L-1, OXA, CLX and DCX (10 mg L-1 each) disappeared to an extent of 31, 46 and 71%. However, quantitative antibiotic removal (~90%) was noticed when Cu0Fe0 bimetallic was used at lesser load (r = 20 g L-1)under vortex mixing. On the other hand, non-disturbed systems showed partial removal (~ 25%) of antibiotics over 7 h of reaction at r = 10 g L-1 (Fe0) while almost complete removals were noticed for the Cu0Fe0 bimetallic system for the same metal load and period e.g. 75, 79 and 86% removal for OXA, CLX and DCX respectively.

Gli stili APA, Harvard, Vancouver, ISO e altri

30

Štyriaková, Iveta. "Influence of Chelators on Iron Solubilization from Quartz and Feldspars by Bioleaching". Advanced Materials Research 20-21 (luglio 2007): 87–90. http://dx.doi.org/10.4028/www.scientific.net/amr.20-21.87.

Testo completo

Abstract (sommario):

Ultra-fine iron particles are difficult to treat by conventional mineral processing methods. Thus bioleaching is an attractive alternative for effective removal of iron minerals. The removal of oxidic Fe-phases from industrial silicates via bioleaching needs to be optimized with regard to the rate of iron reduction and dissolution. A new role for chelators as the low addition of AQDS or NTA during bacterial quality improvement of non-metallics, resulted in stimulating of Fe dissolution under non-controlled anaerobic conditions. AQDS stimulated bacterial iron reduction and Fe2+ concentration in solution was higher than Fe3+. However, NTA non-stimulated iron reduction, but increased bacterial iron dissolution in form of Fe3+. Changes in iron removal from samples were used to assess the chelator effectiveness of the heterotrophic bioleaching process. Chelators might be added to iron-contaminated non-metallics during bioleaching processes for stimulation of rate of iron removal.

Gli stili APA, Harvard, Vancouver, ISO e altri

31

Cui, Li, Rui Gao, Fang Qin Cheng, Jian Feng Li e Xu Ming Wang. "Remediation of Contaminated Surface Water by Permeable Reactive Barriers (PRBs): Lab-Scale Experiments with Four Industrial Wastes as Reactive Media". Applied Mechanics and Materials 295-298 (febbraio 2013): 1850–54. http://dx.doi.org/10.4028/www.scientific.net/amm.295-298.1850.

Testo completo

Abstract (sommario):

Four industrial wastes: iron scraps, ceramsite, fly ash and steel slag were studied as reactive media for COD removal from the Fenhe River. Leaching tests demonstrated that iron scraps and ceramsite were relatively stable compared to steel slag and fly ash. Ca2+ was the main leaching ion. Batch experiment results showed that iron scraps and steel slag had better COD removal efficiency than ceramsite and fly ash. It was also found that the initial pH was important for COD removal and the COD removal efficiency of iron scraps was linearly correlated with the initial pH (R2=0.982). Compared to batch experiments, COD removal was much higher in column tests, which were about 70%, 54%, 46% for iron scraps, steel slag and ceramsite respectively.

Gli stili APA, Harvard, Vancouver, ISO e altri

32

Shi, Xue, Xue Wei Dai, Jiang Wu, Xian Li, Yi Ran Zhang, Yin Xia Cao, Can Li et al. "Experimental Study on Titanium Based Photocatalyst and its Catalytic Oxidation on Flue Gas Mercury". Applied Mechanics and Materials 252 (dicembre 2012): 293–97. http://dx.doi.org/10.4028/www.scientific.net/amm.252.293.

Testo completo

Abstract (sommario):

This paper mainly studied the effects of different iron-doped volume on photo-catalytic oxidation of TiO2 for mercury removal. Through the photocatalytic oxidation system, we evaluated the elemental mercury removal performance of TiO2 with iron-doped mass ratio of 0.5%, 1%, 2% and 3%. While the iron-doped mass ratio were 0.5%, 1%, 2% and 3%, the elemental mercury removal efficiency were 70.83%，52.89%，72.32% and 62.39% respectively, the removal efficiency increased firstly, then declined, and 2% iron-doped was the most appropriate

Gli stili APA, Harvard, Vancouver, ISO e altri

33

Fu, Jin Xiang, Hong Mei Li, Peng Fei Yu e Kai Zhao. "Research on Waste Materials with Decentralized White Spirit Wastewater Pretreatment by Fe-C Micro-Electrolysis". Applied Mechanics and Materials 644-650 (settembre 2014): 5419–22. http://dx.doi.org/10.4028/www.scientific.net/amm.644-650.5419.

Testo completo

Abstract (sommario):

This research adopts the important iron electrolysis, removal of the wastewater of high COD, SS, phosphorus pretreatment experiment. Discusses the different iron dosing quantity, iron carbon ratio, and pH value, reaction time on the COD and turbidity, the influence of the phosphorus removal effect. Studies show that iron important electrochemical test in brewery wastewater treatment static optimal processing conditions for: water pH value is 4, 5% dosage of iron filings, 60 min temperature response, COD removal rate was 52.31%. When the iron carbon ratio of 2:1, removing effect is good, can reach 54.53%.

Gli stili APA, Harvard, Vancouver, ISO e altri

34

Lee, Jung Eun, e Young-Kwon Park. "Applications of Modified Biochar-Based Materials for the Removal of Environment Pollutants: A Mini Review". Sustainability 12, n. 15 (29 luglio 2020): 6112. http://dx.doi.org/10.3390/su12156112.

Testo completo

Abstract (sommario):

The biochar treated through several processes can be modified and utilized as catalyst or catalyst support due to specific properties with various available functional groups on the surface. The functional groups attached to the biochar surface can initiate active radical species to play an important role, which lead to the destruction of contaminants as a catalyst and the removal of adsorbent by involving electron transfer or redox processes. Centering on the high potential to be developed in field applications, this paper reviews more feasible and sustainable biochar-based materials resulting in efficient removals of environmental pollutants as catalyst or support rather than describing them according to the technology category. This review addresses biochar-based materials for utilization as catalysts, metal catalyst supports of iron/iron oxides, and titanium dioxide because the advanced oxidation process using iron/iron oxides or titanium dioxides is more effective for the removal of contaminants. Biochar-based materials can be used for the removal of inorganic contaminants such as heavy meals and nitrate or phosphate to cause eutrophication of water. The biochar-based materials available for the remediation of eutrophic water by the release of N- or P-containing compounds is also reviewed.

Gli stili APA, Harvard, Vancouver, ISO e altri

35

Wang, Ya'e, Jie Li, Siyuan Zhai, Zhiyong Wei e Juanjuan Feng. "Enhanced phosphorus removal by microbial-collaborating sponge iron". Water Science and Technology 72, n. 8 (29 giugno 2015): 1257–65. http://dx.doi.org/10.2166/wst.2015.323.

Testo completo

Abstract (sommario):

The collaborative and mutually reinforcing phosphorus removal in domestic wastewater in a sponge iron and microorganisms system was studied through a laboratory and a pilot scale experiment. The results showed that the total phosphorus concentration of the effluent of less than 0.5 mg/L could be achieved. The results also support that the biochemical reaction accelerated the iron electrochemical corrosion. As a driving force, iron bacteria strengthened the chemical oxidation of Fe(II) to Fe(III). The chemical precipitation of Fe(III) is the main form of phosphorus removal. In addition, there exists adsorption phosphorus removal by phosphate-accumulating organisms. The mechanism of the enhanced phosphorus removal by microbial-collaborating sponge iron was thus proposed.

Gli stili APA, Harvard, Vancouver, ISO e altri

36

Nguyen, Thao Thi, Than Ngoc Truong e Binh Ngoc Duong. "IMPACT OF ORGANIC ACID ADDITION ON THE FORMATION OF PRECIPITATED IRON COMPOUNDS". Acta Metallurgica Slovaca 22, n. 4 (2 dicembre 2016): 259. http://dx.doi.org/10.12776/ams.v22i4.831.

Testo completo

Abstract (sommario):

In this work, acetic and citric acids were used along with ammonium chloride in the removal of iron from reduced Hatinh ilmenite. Iron removal was carried out at 70ºC, 4 liter/min of air flow rate, 7/1 of liquid/solid ratio and 0.5% NH4Cl as catalyst. After 9 hours, metallic iron was decreased from 30.3% in reduced ilmenite to 0.5% in synthetic rutile. The addition of 0.4% acetic acid into NH4Cl solution reduces removal time to 5 hours, residual metallic iron (RMI) was also 0.5%. The addition of 0.4% citric acid also reduces removal time to 5 hours, RMI was reduced to 0.33%. The rusting rate of metallic iron increased when acid concentration increased from 0.1 to 1%. The results indicated that acetic and citric acids could be used as additional catalysts along with NH4Cl in the removal of metallic iron in reduced ilmenite. The acid have the capability to form complexes with iron and also showed impact on the formation of precipitated iron compounds.

Gli stili APA, Harvard, Vancouver, ISO e altri

37

Ansone, L., M. Klavins, A. Robalds e A. Viksna. "Use of Biomass for Removal of Arsenic Compounds". Latvian Journal of Chemistry 51, n. 4 (1 dicembre 2012): 324–35. http://dx.doi.org/10.2478/v10161-012-0018-7.

Testo completo

Abstract (sommario):

Water contamination with arsenic compounds is a serious problem. One of the solutions is to develop new sorbents based on natural materials that would be cost-effective and environmentally friendly. New sorbents based on biomaterial impregnation with iron oxyhydroxides have been developed. Raw peat material, iron modified-peat, sand, iron modifiedbiomass (shingles, straw) were used for removal of arsenic compounds. The highest sorption capacity was observed for iron modified-peat. Kinetic studies indicated that most of arsenates were removed within 2 hours, and arsenate sorption on iron modified-peat was characterized by the pseudo-second order rate law.

Gli stili APA, Harvard, Vancouver, ISO e altri

38

Maksimov, L. I., e V. V. Mirinov. "TECHNOLOGY IMPROVEMENT OF HIGH-DISPERSIVE METALLIC IRON POWDERS BASED ON SEDIMENTS OF IRON REMOVAL STATION". Vestnik Tomskogo gosudarstvennogo arkhitekturno-stroitel'nogo universiteta. JOURNAL of Construction and Architecture 22, n. 2 (30 aprile 2020): 162–73. http://dx.doi.org/10.31675/1607-1859-2020-22-2-162-173.

Testo completo

Abstract (sommario):

Sediments from iron removal stations are a source of environmental pollution. It is necessary to find effective and eco-friendly methods of sediment disposal. The paper investigates the properties of iron-containing sediment in order to develop a technology for its further utilization. It is shown that sediments from the iron removal station of Velizhansky water intake have a stable chemical composition with about 70 % Fe2O3, and a stable particle size distribution, i.e. 20 μm for ≈ 87 % of particles. These parameters allow developing a flow chart for iron reduction in heated carbon monoxide. The involvement of sediments from iron removal stations in the high-dispersive metallic iron powder production eliminates the sediment deposit at landfills or storage tanks and creates a new raw material base for additive technologies.

Gli stili APA, Harvard, Vancouver, ISO e altri

39

Rana, J. K., K. A. Shah e K. J. Maisuria. "Electrocoagulation using scrap materials for removal of dye with different connection modes and electrode combinations". IOP Conference Series: Earth and Environmental Science 1086, n. 1 (1 settembre 2022): 012039. http://dx.doi.org/10.1088/1755-1315/1086/1/012039.

Testo completo

Abstract (sommario):

Abstract This study analyses the efficiency of electrocoagulation (EC) process by utilizing discarded metal scrap of Iron (Fe) and Aluminium (Al) as electrodes for decolourization of azo dye, Acid Yellow 36 (AY36). Different modes of connection such as mono polar parallel (M-P), mono polar series (M-S) and bi polar series (B-S) were investigated for the performance of percent colour removal and Electrical Energy Consumption (ENC). Within these connections, different electrode arrangements, such as Iron-Aluminium-Iron-Aluminium, Aluminium-Iron-Aluminium-Iron, Iron-Iron-Iron-Iron and Aluminium-Aluminium-Aluminium-Aluminium were analyzed for the dye removal efficiency. The parameters varied during the experimental runs were current density (CD) and pH. M–S showed maximum colour removal of 99.2% with system of mixed electrode Fe–Al–Fe–Al at CD 10 A/m2 and ENC 0.322 Kwh/Kg dye removed. Whereas M-P showed 98.4% colour removal with hybrid system Fe–Al–Fe–Al at CD of 20 A/m2 with ENC 0.209 Kwh/Kg dye removed. B-S showed 99.1% colour removal with mixed electrode system Al-Fe-Al-Fe at CD of 20 A/m2 and ENC 0.86 Kwh/Kg dye removed. Overall, M-S mode gave the maximum colour removal, while M-P gave minimum ENC. The study proved useful in terms of lowering the cost of electrocoagulation by using scrap metal as electrodes and choosing the right electrode combination and connection mechanism.

Gli stili APA, Harvard, Vancouver, ISO e altri

40

M. K, Krishna, Manjunath H.N e Ayesha Siddiqa. "TREATMENT OF SERVICE STATION WASTEWATER USING ELECTROCOAGULATION PROCESS". International Journal of Research -GRANTHAALAYAH 5, n. 7 (31 luglio 2017): 348–53. http://dx.doi.org/10.29121/granthaalayah.v5.i7.2017.2140.

Testo completo

Abstract (sommario):

The various electrodes such as iron, aluminium, stainless steel and graphite are used in this study. Main objectives of the present paper is to evaluate the removal of COD, pH, TDS and oil and grease from the automobile wastewater by Electro coagulation using iron as Monopolar configuration at different voltages and electrolysis time. To study the effect of inter electrode spacing and effect of different initial pH for the removal of selected parameter at constant voltage for the iron electrode. The removal efficiency decreases with increase in electrode spacing as 71.2% of COD, 96.5% of TDS and 88.76% of oil and grease removal was achieved with iron electrode.

Gli stili APA, Harvard, Vancouver, ISO e altri

41

Sukmilin, Apiradee, e Ratsamee Sangsirimongkolying. "Removal of Iron from Groundwater by Ozonation: The Response Surface Methodology for Parameter Optimization". Environment and Natural Resources Journal 19, n. 4 (14 giugno 2021): 330–36. http://dx.doi.org/10.32526/ennrj/19/2020286.

Testo completo

Abstract (sommario):

This research studied the possibility of using ozone to remove iron from groundwater. The optimum conditions were investigated using a Box-Behnken experiment design with statistical analysis by response surface technique. The three parameters investigated, pH (6.0-8.0), hardness (300-500 mg/L as CaCO3) and removal time (10 to 60 min) were independent parameters of iron removal. Data was examined for optimal conditions and included main effects and their interactions. Analysis of variance indicated that the proposed quadratic model successfully interpreted the experimental data with a coefficient of determination (R2) of 98.83% and adjusted R2 of 96.72%. Through this model, it could predict the iron removal efficiency under variable conditions. Furthermore, the optimum conditions were pH 6.99, hardness of 300 mg/L as CaCO3, and 10 min of reaction time. The predicted iron removal efficiency obtained from the model under the optimum conditions was 99.00%. The experiment confirmed that the optimum condition which validated the model’s accuracy of iron removal efficiency was 98.45%. The results showed that ozone can remove iron from groundwater.

Gli stili APA, Harvard, Vancouver, ISO e altri

42

Kang, Xiao Rong, e Ya Li Liu. "Microbial Community Analysis in Bio-Filter Bed of Iron and Manganese Removal Treating High Iron, Manganese and Ammonia Nitrogen Groundwater". Advanced Materials Research 777 (settembre 2013): 238–41. http://dx.doi.org/10.4028/www.scientific.net/amr.777.238.

Testo completo

Abstract (sommario):

The integrated process of spray aeration, falling water aeration and bio-filter bed was used for treating groundwater with high iron, manganese and ammonia nitrogen (NH4+-N). The removal efficiencies of iron, manganese and NH4+-N reached 99.1%, 95.0% and 85.2%, and corresponding effluent iron and manganese decreased to 0.1 and 0.05 mg/L. Microbial analysis results indicated that theβ-Proteobacteriawas predominant microorganisms, in whichGallionellaandLeptothrixwere main iron-removal bacteria and manganese-removal bacteria, respectively. Simultaneously,Pseudomona, belonged toγ-Proteobacteria, could absorb and oxidize free manganese to be manganese dioxide (MnO2) by extracellular oxidase.

Gli stili APA, Harvard, Vancouver, ISO e altri

43

Ofoegbu, Stanley Udochukwu. "Technological Challenges of Phosphorus Removal in High-Phosphorus Ores: Sustainability Implications and Possibilities for Greener Ore Processing". Sustainability 11, n. 23 (29 novembre 2019): 6787. http://dx.doi.org/10.3390/su11236787.

Testo completo

Abstract (sommario):

With the present rates of iron ore consumption, currently unusable, high-phosphorus iron ore deposits are likely to be the iron ores of the future as higher-grade iron ore reserves are depleted. Consequently, the design and timely development of environmentally-benign processes for the simultaneous beneficiation of high-phosphorus iron ores and phosphorus recovery, currently a technological challenge, might soon become a sustainability challenge. To stimulate interest in this area, phosphorus adsorption and association in iron oxides/hydroxyoxides, and current efforts at its removal, have been reviewed. The important properties of the most relevant crystalline phosphate phases in iron ores are highlighted, and insights provided on plausible routes for the development of sustainable phosphorus recovery solutions from high-phosphorus iron ores. Leveraging literature information from geochemical investigations into phosphorus distribution, speciation, and mobility in various natural systems, key knowledge gaps that are vital for the development of sustainable phosphorus removal/recovery strategies and important factors (white spaces) not yet adequately taken into consideration in current phosphorus removal/recovery solutions are highlighted, and the need for their integration in the development of future phosphorus removal/recovery solutions, as well as their plausible impacts on phosphorus removal/recovery, are put into perspective.

Gli stili APA, Harvard, Vancouver, ISO e altri

44

Xie, Jing Liang, Fei Fei Chi, Fan Li Meng e An Ran Peng. "Application of Iron Powder Reduction Method to Remove Heavy Metals in Waste Pickling Acid". Materials Science Forum 980 (marzo 2020): 377–86. http://dx.doi.org/10.4028/www.scientific.net/msf.980.377.

Testo completo

Abstract (sommario):

The removal of heavy metals in waste pickling acid by iron powder reduction was studied. The effects of reaction time, reaction temperature and dosage of iron powder on the removal efficiency of Zn, Cr, Ni and Pb in waste pickling acid were investigated. The results showed that, the removal rate of Cr tended to be stable after 2 h of reaction under magnetic stirring. After 4 hours, the removal rate of Zn,Ni and Pb tended to be stable. The temperature was increased from 20°C to 90 °C, the removal rates of Ni and Pb could be increased by 9.09% and 11.6%, while the removal rates of Zn and Cr were only increased by 1.15% and 2.85%; Increasing the dosage of iron powder was beneficial to the removal of heavy metals in waste pickling acid, and the combined amount of free acid in the waste acid would affect the removal efficiency of heavy metals. The research results had important guiding significance for the practical application of iron powder reduction method in the heavy metal purification project of waste pickling acid.

Gli stili APA, Harvard, Vancouver, ISO e altri

45

Yang, Chang-Qiao, e Su-Qin Li. "Kinetics of iron removal from quartz under ultrasound-assisted leaching". High Temperature Materials and Processes 39, n. 1 (7 settembre 2020): 395–404. http://dx.doi.org/10.1515/htmp-2020-0081.

Testo completo

Abstract (sommario):

AbstractKinetics of iron removal from quartz under the ultrasound-assisted leaching was explored in this paper, and the effects of temperature, leaching time, stirring speed and ultrasonic input power on iron removal were studied. The results revealed that the reaction kinetics followed the shrinking core model and the product layer internal diffusion was the rate-determining step in the ultrasound-assisted leaching process. The activation energy of the ultrasonic-assisted leaching reaction was 27.72 kJ/mol, which was 7.28 kJ/mol higher than that of the regular method. Moreover, the kinetic equation and mathematical model of iron removal from quartz were established. Compared with the regular leaching, only 40 min were required for the ultrasound-assisted leaching process to achieve an iron removal rate of up to 74%. Under the optimal parameters, SiO2 content of concentrate increased from 99.5828% to 99.9047%, and Fe2O3 content reduced from 0.0857% to 0.0223%. Additionally, it was found that the iron removal rate increased with increasing temperature, stirring speed or ultrasonic power.

Gli stili APA, Harvard, Vancouver, ISO e altri

46

Elsheikh, Mohamed, H. Guirguis e A. Fathy. "Removal of iron and manganese from groundwater: a study of using potassium permanganate and sedimentation". MATEC Web of Conferences 162 (2018): 05018. http://dx.doi.org/10.1051/matecconf/201816205018.

Testo completo

Abstract (sommario):

Experiments are done for different combinations of Fe+2 and Mn+2 concentrations. The obtained results show that Potassium Permanganate (PP) gives good results in iron and manganese removal. By using PP dose near to half of the theoretically required one, it can remove up to 100 % and 90 % of iron and manganese, respectively over different tested concentrations at pH=7.0. Increasing rate of filtration influences the Mn+2 removal process obviously. Sedimentation is required when combined concentrations of iron and manganese are greater than 5.0 ppm to reduce filter rapid clogging. Using conventional treatment with adding alum, flocculation, sedimentation and filtration can remove up to 97% and 18% of iron and manganese, respectively. Using PP in addition to alum enhances manganese removal but decreases iron removal. However, using alum with increasing pH to 10 leads to 100 % and 95 % of Fe+2 and Mn+2 removal and increases filter working period.

Gli stili APA, Harvard, Vancouver, ISO e altri

47

Nkurunziza, T., J. B. Nduwayezu, E. N. Banadda e I. Nhapi. "The effect of turbidity levels and Moringa oleifera concentration on the effectiveness of coagulation in water treatment". Water Science and Technology 59, n. 8 (1 aprile 2009): 1551–58. http://dx.doi.org/10.2166/wst.2009.155.

Testo completo

Abstract (sommario):

Laboratory experiments were carried out to assess the water purification and antimicrobial properties of Moringa oleifera (MO). Hence different concentrations (25 to 300 mg/L) were prepared from a salt (1 M NaCl) extract of MO fine powder and applied to natural surface water whose turbidity levels ranged from 50 to 450 NTU. The parameters determined before and after coagulation were turbidity, pH, colour, hardness, iron, manganese and Escherichia coli. The experiments showed that turbidity removal is influenced by the initial turbidity since the lowest turbidity removal of 83.2% was observed at 50 NTU, whilst the highest of 99.8% was obtained at 450 NTU. Colour removal followed the same trend as the turbidity. The pH exhibited slight variations through the coagulation. The hardness removal was very low (0 to 15%). However, high removals were achieved for iron (90.4% to 100%) and manganese (93.1% to 100%). The highest E. coli removal achieved was 96.0%. Its removal was associated with the turbidity removal. The optimum MO dosages were 150 mg/L (50 NTU and 150 NTU) and 125 mg/L for the rest of the initial turbidity values. Furthermore all the parameters determined satisfied the WHO guidelines for drinking water except for E. coli.

Gli stili APA, Harvard, Vancouver, ISO e altri

48

Šimkovič, Karol, Ján Derco e Mária Valičková. "Removal of selected pesticides by nano zero-valent iron". Acta Chimica Slovaca 8, n. 2 (1 ottobre 2015): 152–55. http://dx.doi.org/10.1515/acs-2015-0026.

Testo completo

Abstract (sommario):

Abstract This paper is focused on the possibility of using iron nanoparticles (nZVI - nano zero-valent iron) to remove selected specific synthetic substances, such as hexachlorobutadiene, pentachlorobenzene, hexachlorobenzene, lindane and heptachlor. Experimental measurements were performed in order to evaluate the effectiveness of the removal of substances and their specific removal rate. Evaluation of the results shows that nanoiron NANOFER 25 is a convenient reactant for the removal of heptachlor, lindane and hexachlorobenzene; while for pentachlorbenzene and hexachlorobutadiene removal, longer contact times are necessary to achieve significant removal efficiencies.

Gli stili APA, Harvard, Vancouver, ISO e altri

49

de Baar, HJW, LJA Gerringa, P. Laan e KR Timmermans. "Efficiency of carbon removal per added iron in ocean iron fertilization". Marine Ecology Progress Series 364 (29 luglio 2008): 269–82. http://dx.doi.org/10.3354/meps07548.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

50

Karschunke, K., e M. Jekel. "Arsenic removal by iron hydroxides, produced by enhanced corrosion of iron". Water Supply 2, n. 2 (1 aprile 2002): 237–45. http://dx.doi.org/10.2166/ws.2002.0069.

Testo completo

Abstract (sommario):

Results of lab-scale experiments for arsenic removal from drinking water are presented. Arsenate(V)-ions were adsorbed on ferric hydroxides which were formed in-situ by corrosion of elemental iron in oxygenated water. Natural corrosion of fine iron wool was suitable to remove effectively high but realistic arsenic concentrations of 500 μg/L from drinking water. As the corrosion rate decreased significantly in time, two different methods to enhance the corrosion were tested and evaluated: galvanic corrosion using iron-copper contact elements and the application of an external voltage. The iron-copper contact elements showed promising results (a high and stable corrosion rate) but were bearing the risk of copper release when the contact broke down. The application of voltage led to an enhanced release of iron-ions but was coupled with a cathodic formation of hydrogen from water. The generation of hydrogen is a very undesirable effect for any practical application. Irrespective of the mode of corrosion, a post-treatment step (sand filtration) was required to remove the arsenic loaded rust particles from the effluent. In the final effluent, drinking water quality was reached by all the methods.

Gli stili APA, Harvard, Vancouver, ISO e altri

Articoli di riviste sul tema "Iron removal"

Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili