Journal articles: 'Sewage sludge anaerobically digested'

1

Cheng, H. F., S. Y. Chen, and J. G. Lin. "Hazardous organic matters in municipal sewage sludge in Taiwan." Water Science and Technology 44, no. 10 (November 1, 2001): 65–70. http://dx.doi.org/10.2166/wst.2001.0582.

Full text

Abstract:

Application of municipal sewage sludge to agricultural land has attracted significant attention in recent years because it conserves abundant nutrients and hydrocarbons that can be used as a soil amendment. The presence of hazardous organic matters (HOMs) in sewage sludge limits the feasibility of reuse of sewage sludge. The purpose of this study was to investigate the types and the concentrations of HOMs in municipal sewage sludge in Taiwan. An efficient SFE/GC/MS method was used to determine HOMs in sludge samples. The results indicated that di-(2-ethylhexyl) phthalate (DEHP) was persistently found in both aerobically and anaerobically digested sludges. 4-nonylphenol (4-NP) was only found in anaerobically digested sludges. Both DEHP and 4-NP have been characterized as endocrine disrupting chemicals (EDCs) or environmental endorine disruptors (EEDs). It suggested that sludges containing high levels of DEHP and 4-NP need further treatment and reduction of possible impacts on the environment before their reuse as soil fertilizers.

APA, Harvard, Vancouver, ISO, and other styles

2

Kitada, K., A. Ito, K. Yamada, J. Aizawa, and T. Umita. "Biological leaching of heavy metals from anaerobically digested sewage sludge using indigenous sulfur-oxidizing bacteria and sulfur waste in a closed system." Water Science and Technology 43, no. 2 (January 1, 2001): 59–65. http://dx.doi.org/10.2166/wst.2001.0073.

Full text

Abstract:

The utilization of indigenous sulfur-oxidizing bacteria and sulfur waste was investigated in order to remove heavy metals from anaerobically digested sewage sludge economically. Indigenous sulfur-oxidizing bacteria existing in anaerobically digested sewage sludge were activated by adding elemental sulfur to the sludge and then the bacteria were isolated. It was found that indigenous sulfur-oxidizing bacteria could utilize sulfur waste generated by desulfurization of digestion gas as a substrate. Then, biological leaching of heavy metals from anaerobically digested sewage sludge was carried out using indigenous sulfur-oxidizing bacteria and sulfur waste. By adding sulfur waste to sewage sludge, sulfuric acid was produced by the bacteria and the sludge pH decreased. Heavy metals in sewage sludge were effectively removed owing to the decrease of pH. The optimum amount of sulfur waste added to decrease the pH sufficiently was 5g/L when the sludge concentration was 2%. It was presented that the biological leaching of heavy metals from sewage sludge can be carried out in a closed system, where all required materials are obtained in a sewage treatment plant.

APA, Harvard, Vancouver, ISO, and other styles

3

Monea, Marlena Cristina, Carsten Meyer, Heidrun Steinmetz, Harald Schönberger, and Asya Drenkova-Tuhtan. "Phosphorus recovery from sewage sludge – phosphorus leaching behavior from aluminum-containing tertiary and anaerobically digested sludge." Water Science and Technology 82, no. 8 (August 31, 2020): 1509–22. http://dx.doi.org/10.2166/wst.2020.414.

Full text

Abstract:

Abstract Systematic investigations of the acidic dissolution of phosphorus (P), aluminum (Al), iron (Fe), and calcium (Ca) from Al-containing tertiary sludge were carried out in this work. The results were compared with the dissolution behavior of Al-containing anaerobically digested sludge to evaluate the P recovery potential in the form of struvite from tertiary sludge versus anaerobically digested sludge. Additional investigations of synthetically produced Al sludge served as a comparison for the dissolution behavior of P and Al without the influence of other contaminants (metals, biomass). In addition, the acid consumption was analyzed as a function of the target pH during the dissolution. The dissolution efficiency of ortho-phosphate in tertiary and anaerobically digested sludge after acid treatment at pH 2 was ∼90%. The dissolution efficiency of Al and Ca in tertiary sludge was also ∼90% at pH 2, while the release efficiency of Al and Ca in anaerobically digested sludge was lower, ∼70% at pH 2. In tertiary sludge, about 75% of Fe was found dissolved at pH 2, whereas in anaerobically digested sludge this value was higher, ∼90%. Based on the experimental data, it can be concluded that significant dissolution of phosphorus from Al-containing tertiary sludge can take place at pH < 3. The highest sulfuric acid consumption for P dissolution was observed in the case of tertiary sludge at pH 2.

APA, Harvard, Vancouver, ISO, and other styles

4

Chu, C. W., C. S. Poon, and R. Y. H. Cheung. "Characterization of raw sludge, chemically modified sludge and anaerobically digested sludge in Hong Kong." Water Science and Technology 38, no. 2 (July 1, 1998): 25–32. http://dx.doi.org/10.2166/wst.1998.0095.

Full text

Abstract:

Chemically Enhanced Primary Treatment (CEPT) or Chemically Assisted Primary Sedimentation (CAPS) is being employed at the new sewage work on Stonecutters Island as part of the Strategic Sewage Disposal Scheme (SSDS) in Hong Kong. CAPS involves the use of chemical coagulants (such as lime or ferric chloride) to induce coagulation or flocculation and let these finely-divided particles form large aggregates (floc) so that they can settle out within a reasonable period of time. In this study, five sludge samples collected from different sewage treatment plants in Hong Kong were physically and chemically characterized. They were chemically modified sludge from Stonecutters Island (CAPS) raw sludge from Tai Po and Yuen Long Sewage Treatment Plant (STP) (rTP & rYL) and anaerobically digested sludge from Tai Po and Yuen Long STP (dTP & dYL). It was found that CAPS sludge was better than other 4 sludge samples in terms of settleability and dewaterability. CAPS sludge contained significant higher amounts (p<0.01) of extractable compounds than other sludges (except NO3− for dTP, NH4+ and PO43− for dYL). The concentration of total N and P in CAPS sludge were significantly higher (p<0.01) than other sludges (except dYL). The concentrations of total Cu, Pb, Ni, Cd, Cr and K in the CAPS sludge were also significantly higher (p<0.01) than other sludge samples. Most of the metals (Cr, Pb, Cr and Zn) in CAPS sludge were associated with the organically-bounded phase. It is concluded that there are significant differences in both physical and chemical properties between the chemically modified sludge and biological treated sludges.

APA, Harvard, Vancouver, ISO, and other styles

5

Parravicini, V., K. Svardal, R. Hornek, and H. Kroiss. "Aeration of anaerobically digested sewage sludge for COD and nitrogen removal: optimization at large-scale." Water Science and Technology 57, no. 2 (January 1, 2008): 257–64. http://dx.doi.org/10.2166/wst.2008.020.

Full text

Abstract:

The paper will report about the experiences at an Austrian large wastewater treatment plant of 720,000 population equivalents, where anaerobically digested sewage sludge is further stabilised under aerobic conditions. Enhanced stabilisation of the anaerobically digested sludge was required at the plant in order to get a permit for landfill disposal of the dewatered stabilized sludge. By implementing a post-aeration treatment (SRT ∼ 6d; 36 °C) after anaerobic digestion the organic content of the anaerobically well digested sludge can be decreased by 16%. Investigations on site showed that during digested sludge post-aeration anoxic phases for denitrification are needed to provide stable process conditions. In this way the pH value can be kept in a more favourable range for micro-organisms and concrete structures. Additionally, inhibition of the biological process due to nitrite accumulation can be avoided. By optimising the aeration/pause ratio ∼ 45% of total nitrogen in digested sludge can be removed. This significantly improves nitrogen removal efficiency at the wastewater treatment plant. NH4-removal occurs mainly through nitritation and denitritation with an efficiency of 98%. The costs/benefit analysis shows that post-aeration of digested sludge results in an increase of total annual costs for wastewater treatment of only 0.84%, corresponding to 0.19 Euro/pe/a. Result of molecular biological analyses (DGGE) indicate that all four ammonium-oxidizing bacteria species present in activated sludge can survive anaerobic digestion, but only two of them can adapt in the digested sludge post-aeration tanks. Additionally, in the post-aerated digested sludge a further ammonium-oxidizing bacteria species was identified.

APA, Harvard, Vancouver, ISO, and other styles

6

Wong, J. W. C., and X. Y. Gu. "Enhanced heavy metal bioleaching efficiencies from anaerobically digested sewage sludge with coinoculation of Acidithiobacillus ferrooxidans ANYL-1 and Blastoschizomyces capitatus Y5." Water Science and Technology 50, no. 9 (November 1, 2004): 83–89. http://dx.doi.org/10.2166/wst.2004.0541.

Full text

Abstract:

Prolonged bioleaching period was required to remove heavy metals from anaerobically digested sewage sludge in the presence of low molecular weight organic acids. The purpose of the present study was therefore to enhance metal solubilization efficiencies through introducing organic acid-degrading microorganisms into this artificial bioleaching system. An acetic and propionic acid-degrading yeast Blastoschizomyces capitatus Y5 was successfully isolated from a local Yuen Long sewage sludge and it could achieve optimum growth in synthetic liquid media containing 2,000 mg l-1 acetic acid or 1,000 mg l-1 propionic acid. When it was inoculated simultaneously with Acidithiobacillus ferrooxidans ANYL-1 into anaerobically digested sewage sludge, which contained 648 mg l-1 acetic acid and 731 mg l-1 propionic acid, both acids were completely decomposed within 24 hours. As a result, ferrous iron oxidation was greatly improved, resulting in enhanced metal solubilization. Compared with the 8, 10 and 12 days required for maximum solubilization of Zn, Cu and Cr for the control sludge, the bioleaching period was significantly shortened to 4, 5 and 8 days respectively for sludge receiving co-inoculation.

APA, Harvard, Vancouver, ISO, and other styles

7

Matos, Antonio T., Isabela C. C. Diniz, Mateus P. Matos, Alisson C. Borges, and Adriana A. Pereira. "Degradation rate of anaerobically digested sewage sludge in soil." Journal of Water, Sanitation and Hygiene for Development 8, no. 1 (November 16, 2017): 17–26. http://dx.doi.org/10.2166/washdev.2017.138.

Full text

Abstract:

Abstract The objective of this study was to monitor the degradation and obtain the mineralization fraction of anaerobically digested sludge, also known as digestate, under field conditions, when applied to the surface or incorporated into the soil. Sludge was applied to a dystrophic Inceptisol at a dose of 500 kg ha–1 yr–1 of total nitrogen, where the monitoring period of the mineralization process lasted 131 days. Samples of the soil-residue mixture were collected for analysis of the total organic carbon (TOC) and easily oxidizable organic carbon (OOC), total, ammonia, nitrate and organic nitrogen (ON). The annual mineralization fractions of the digestate, estimated based on the difference between the initial and final contents of TOC, OOC and ON in samples of the material collected, were 99.5 and 100%, respectively, when incorporated with the soil or applied to the soil surface.

APA, Harvard, Vancouver, ISO, and other styles

8

Pathak, Ashish, M. G. Dastidar, and T. R. Sreekrishnan. "Bioleaching of heavy metals from anaerobically digested sewage sludge." Journal of Environmental Science and Health, Part A 43, no. 4 (February 19, 2008): 402–11. http://dx.doi.org/10.1080/10934520701795624.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Nordin, Annika C., Jesper Olsson, and Björn Vinnerås. "Urea for Sanitization of Anaerobically Digested Dewatered Sewage Sludge." Environmental Engineering Science 32, no. 2 (February 2015): 86–94. http://dx.doi.org/10.1089/ees.2013.0230.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Samorì, Chiara, Alisar Kiwan, Cristian Torri, Roberto Conti, Paola Galletti, and Emilio Tagliavini. "Polyhydroxyalkanoates and Crotonic Acid from Anaerobically Digested Sewage Sludge." ACS Sustainable Chemistry & Engineering 7, no. 12 (May 13, 2019): 10266–73. http://dx.doi.org/10.1021/acssuschemeng.8b06615.

Full text

APA, Harvard, Vancouver, ISO, and other styles

11

Ito, A., K. Takahashi, J. Aizawa, and T. Umita. "Enhanced heavy metals removal without phosphorus loss from anaerobically digested sewage sludge." Water Science and Technology 58, no. 1 (July 1, 2008): 201–6. http://dx.doi.org/10.2166/wst.2008.642.

Full text

Abstract:

Heavy metals removal without phosphorus loss from anaerobically digested sewage sludge was investigated by conducting batch experiments using hydrogen peroxide and/or iron sulphate under acidified conditions at pH 3. The addition of hydrogen peroxide to the sludge improved the elution efficiencies of As, Cd, Cu and Zn with phosphorus loss from the sludge. The optimum initial concentrations of hydrogen peroxide were. Respectively. 0.1% for As, Cd, Mn and Zn and 0.5% for Cu and Ni. The combined process of 0.1% hydrogen peroxide and 1 g Fe/L ferric sulphate enhanced the initial elution rate of Cu and Cr compared to the addition of either ferric sulphate or hydrogen peroxide, indicating that oxidants stronger than hydrogen peroxide were produced in the sludge. Furthermore, the combined process immobilised phosphorus in the sludge due to co-precipitation with ferric hydroxide or precipitation as ferric phosphate. It was concluded that there is a possibility that the combined process could remove heavy metals effectively without phosphorus loss from anaerobically digested sewage sludge.

APA, Harvard, Vancouver, ISO, and other styles

12

Hidaka, Taira, Masato Nakamura, Fumiko Oritate, and Fumitake Nishimura. "Utilization of high solid waste activated sludge from small facilities by anaerobic digestion and application as fertilizer." Water Science and Technology 80, no. 12 (December 15, 2019): 2320–27. http://dx.doi.org/10.2166/wst.2020.050.

Full text

Abstract:

Abstract Anaerobic co-digestion of sewage sludge with organic wastes has recently gained attention in small facilities. For small facilities, high solids sludge is suitable for transportation to a centralized co-digester, and direct utilization of the digested sludge as liquid fertilizer is recommended. Effects of high solid and hyperthermophilic pretreatment (80 °C, 24 hr) on anaerobic digestion at low temperatures and utilization as fertilizer are investigated by anaerobic/aerobic digestion and paddy soil incubation experiments. The volatile solids (VS)/total solids (TS) ratio decreases to 0.57(-), and the VS removal rate is approximately 0.7 (-) after long-term aerobic digestion. This is possibly the limitation of biodegradation, even with pretreatment, within engineering time. Substrate TS of 16% (not diluted), 10% and 5% are compared. The effect of substrate TS on biogas production performance (0.2–0.3 NL/gVS-added) is not statistically observed. Laboratory-scale paddy soil incubation experiments are performed fed with anaerobically digested pretreated or not pretreated dewatered sludge as liquid fertilizer. Pretreatment promotes nitrogen mineralization before use as fertilizer, which is helpful to prevent an outflow of surplus ammonia to the environment. The effect of soil type on microbial communities is more significant than that of anaerobically digested sludge conditions.

APA, Harvard, Vancouver, ISO, and other styles

13

Huang, J., M. Elektorowicz, and J. A. Oleszkiewicz. "Dewatering and disinfection of aerobic and anaerobic sludge using an electrokinetic (EK) system." Water Science and Technology 57, no. 2 (January 1, 2008): 231–36. http://dx.doi.org/10.2166/wst.2008.009.

Full text

Abstract:

The objectives of the study were to upgrade sewage sludge to Class A Exceptional Quality biosolids (as defined by US EPA) using an electrokinetics dewatering system. The pathogens monitored were Salmonella spp, and fecal coliforms (FC). Ten bench-scale electrokinetic cells were set up for the disinfection of the following sludges: primary, secondary (attached growth culture and suspended culture), and anaerobically digested sludge. A conditioning liquid was also added to five cells. Blower system to aid in dewatering and drying was used in in four EK cells. Sludge characteristics such as water content, volatile solids content, sulfate and chloride ions concentrations, FC and Salmonella spp. before and after the tests were monitored. The highest total solids content (98% TS) was achieved in the cell with the low voltage gradient, in the presence of the conditioner and with the blower system. An average reduction by 50% of volatile solids was observed. The highest, 11 log-reduction of Salmonella spp. was observed in a cell with anaerobically digested sludge. No fecal coliforms were observed in any of the cells after EK treatment.

APA, Harvard, Vancouver, ISO, and other styles

14

Du, Y. G., T. R. Sreekrishnan, R. D. Tyagi, and Peter G. C. Campbell. "Effect of pH on metal solubilization from sewage sludge: a neural-net-based approach." Canadian Journal of Civil Engineering 21, no. 5 (October 1, 1994): 728–35. http://dx.doi.org/10.1139/l94-078.

Full text

Abstract:

Microbial leaching for heavy metals removal from municipal sewage sludge is a complex biological process. The ultimate metal solubilization achieved depends on the type of sludge involved (nondigested, aerobically digested or anaerobically digested sludge), the decrease in sludge pH as a result of the leaching operation, and the concentration of metals initially present in the sludge. In addition, the system temperature exerts an indirect but strong influence by its effect on the bacterial growth and acid production process. A neural-net-based model was developed to predict the solubilization of six heavy metals, Cd, Cr, Cu, Ni, Pb, and Zn, from sewage sludge using the bioleaching process. The only input parameters required are the type of sludge, initial metal concentrations in the sludge, and the sludge pH. The model yielded satisfactory predictions of metal solubilization when tested with a number of actual experimental data. Key words: heavy metals, microbial leaching, modelling, neural-net, sewage sludge.

APA, Harvard, Vancouver, ISO, and other styles

15

Parravicini, V., K. Svardal, and H. Kroiss. "Post-aeration of anaerobically digested sewage sludge for advanced COD and nitrogen removal: results and cost-benefit analysis at large-scale." Water Science and Technology 57, no. 7 (April 1, 2008): 1087–94. http://dx.doi.org/10.2166/wst.2008.211.

Full text

Abstract:

At a large Austrian municipal wastewater treatment plant enhanced stabilisation of anaerobically digested sewage sludge was required in order to get a permit for landfill disposal of the dewatered stabilized sludge. By implementing a post-aeration treatment after anaerobic digestion the organic content of the anaerobically well digested sludge can be decreased by 16%. Investigations at this plant showed that during digested sludge post-aeration anoxic phases are needed to provide stable process conditions. In this way the pH value can be kept in a more favourable range for micro-organisms and concrete structures. Additionally, under the process conditions applied nitrite accumulation would inhibit the stabilisation process if denitrification is not adequately applied. By optimising the aeration/pause ratio ∼45% of total nitrogen in digested sludge can be removed. NH4-removal occurs through nitritation and denitritation with an efficiency of 98%. This significantly improves nitrogen removal efficiency at the wastewater treatment plant. The costs/benefit analysis shows that post-aeration of digested sludge results in an increase of total annual costs for wastewater treatment of only 0.84%, corresponding to 0.19 Euro/pe/a. Specific costs for nitrogen removal (0.32 Euro/kgN) are comparable with other biological processes for N-removal in reject water.

APA, Harvard, Vancouver, ISO, and other styles

16

Cheng, H. F., S. Y. Chen, and J. G. Lin. "Biodegradation of di-(2-ethylhexyl) phthalate in sewage sludge." Water Science and Technology 41, no. 12 (June 1, 2000): 1–6. http://dx.doi.org/10.2166/wst.2000.0227.

Full text

Abstract:

Di-(2-ethylhexyl) phthalate (DEHP) is widely used as a plasticizer in the production of polyvinyl chloride to impart flexibility to the product. Because of its mutagenicity and carcinogenicity, the presence of DEHP in sludge limits the application of sludge as a soil fertilizer. In this study, sludges were collected from three sewage treatment plants and thirteen wastewater treatment plants of different industries in Taiwan. A supercritical fluid extraction (SFE) was first established as an effective method for determining the concentration of DEHP in sludge. Laboratory-scale land-simulated experiments were performed to investigate the biodegradation of DEHP in sludge under various conditions (moisture, temperature, sunlight and ventilation). DEHP was found in aerobically and anaerobically digested sludges and their values significantly exceeded the restricted concentration of DEHP for sludge land application. DEHP was found to degrade in sludge under the conditions of good ventilation, sufficient sunlight and proper moisture. The indigenous microorganisms in the sludge appeared to dominate the biodegradation of DEHP in sludge. However about 70% of DEHP remained in sludge after 189 d indicating that DEHP is persistent in the environment.

APA, Harvard, Vancouver, ISO, and other styles

17

Ivashechkin, P., P. F. X. Corvini, and M. Dohmann. "Behaviour of endocrine disrupting chemicals during the treatment of municipal sewage sludge." Water Science and Technology 50, no. 5 (September 1, 2004): 133–40. http://dx.doi.org/10.2166/wst.2004.0320.

Full text

Abstract:

Agricultural application of municipal sewage sludge has been emotionally discussed in the last decades, because the latter contains endocrine disrupting chemicals (EDCs) and other organic micro-pollutants with unknown fate and risk potential. Bisphenol A (BPA) was chosen as a model substance to investigate the influence of sludge conditioning on the end-concentration of EDCs in sludge. Adsorption studies with radioactive-labelled BPA showed that more than 75% BPA in anaerobically digested sludge is bound to solids (log Kd = 2.09-2.30; log Koc = 2.72-3.11). Sludge conditioning with polymer or iron (III) chloride alone had no influence on the adsorption of BPA. After conditioning with iron (III) chloride and calcium hydroxide desorption of BPA took place. Apparently, it occurred due to the deprotonation of BPA (pKa = 10.3) as the pH-value reached 12.4 during the process. The same behaviour is expected for other phenolic EDCs with similar pKa (nonylphenol, 17β-estradiol, estron, estriol, 17α-ethinylestradiol). This study shows high affinity of BPA to the anaerobically digested sludge and importance of conditioning in the elimination of EDCs during the sludge treatment. Addition of polymer is favourable in the case of sludge incineration. Conditioning with iron (III) chloride and calcium hydroxide shows advantages for the use of sludge as fertiliser.

APA, Harvard, Vancouver, ISO, and other styles

18

Feltz, Robert E., and Terry J. Logan. "Residual Cadmium Forms in Acid-extracted Anaerobically Digested Sewage Sludge." Journal of Environmental Quality 14, no. 4 (October 1985): 483–88. http://dx.doi.org/10.2134/jeq1985.00472425001400040006x.

Full text

APA, Harvard, Vancouver, ISO, and other styles

19

Huezo, Luis, Juliana Vasco-Correa, and Ajay Shah. "Hydrothermal carbonization of anaerobically digested sewage sludge for hydrochar production." Bioresource Technology Reports 15 (September 2021): 100795. http://dx.doi.org/10.1016/j.biteb.2021.100795.

Full text

APA, Harvard, Vancouver, ISO, and other styles

20

D. B. Anholt, R. J. Ford, J. A. Gillies, and R. L. Kushwaha. "Evaluation of Pellets Produced from Dried, Anaerobically Digested, Sewage Sludge." Applied Engineering in Agriculture 6, no. 5 (1990): 597–600. http://dx.doi.org/10.13031/2013.26434.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

Pryor, Scott W., Anthony G. Hay, and Larry P. Walker. "Nonylphenol in Anaerobically Digested Sewage Sludge from New York State." Environmental Science & Technology 36, no. 17 (September 2002): 3678–82. http://dx.doi.org/10.1021/es015546f.

Full text

APA, Harvard, Vancouver, ISO, and other styles

22

Balmer, P., and R. C. Frost. "Managing Change in an Environmentally Conscious Society: A Case Study, Gothenburg (Sweden)." Water Science and Technology 22, no. 12 (December 1, 1990): 45–56. http://dx.doi.org/10.2166/wst.1990.0099.

Full text

Abstract:

The treatment and disposal of sewage sludge in environmentally conscious societies is becoming increasingly problematical due, in large part, to public attitudes. Strategies have to be developed which either successfully defend existing routes or which manage changes that have public support. A case study of managing change at a large wastewater treatment plant, serving Gothenburg, Sweden, is presented. Three radically different alternatives to the current practice, of lime addition to dewatered raw sludge and disposal to land reclamation, were appraised to a common set of criteria and compared with the existing route. The options considered were incineration, drying of dewatered anaerobically digested sludge, and disposal of dewatered anaerobically digested sludge to underground cavities. An account is given of the public discussion meetings that were held at strategically important times, the views expressed at these being taken into account by GRYAAB's management board in their decision to opt for the disposal of sludge to underground cavities.

APA, Harvard, Vancouver, ISO, and other styles

23

Straub, Timothy M., Ian L. Pepper, and Charles P. Gerba. "Detection of naturally occurring enteroviruses and hepatitis A virus in undigested and anaerobically digested sludge using the polymerase chain reaction." Canadian Journal of Microbiology 40, no. 10 (October 1, 1994): 884–88. http://dx.doi.org/10.1139/m94-140.

Full text

Abstract:

Four undigested and four anaerobically digested sewage sludge samples were analyzed for enteroviruses and hepatitis A virus using seminested and double polymerase chain reaction (PCR), respectively. For enteroviruses, all eight samples were positive when detection was by seminested PCR. Using cell culture all samples except two digested sludge samples were positive. For hepatitis A virus, seven out of eight samples were positive by PCR detection. In all samples, PCR inhibitory substances were removed by passage through Sephadex G-50 and Chelex 100 columns. Overall the PCR methodology was highly successful in identifying the presence of both viruses; however, with this methodology, there was no indication as to whether enteroviruses or hepatitis A viruses not confirmed in cell culture were infectious.Key words: RT-PCR, seminested PCR, sewage sludge, enteroviruses, hepatitis A virus.

APA, Harvard, Vancouver, ISO, and other styles

24

Mondal, Tania, Duncan A. Rouch, Nerida Thurbon, Stephen R. Smith, and Margaret A. Deighton. "Factors affecting decay of Salmonella Birkenhead and coliphage MS2 during mesophilic anaerobic digestion and air drying of sewage sludge." Journal of Water and Health 13, no. 2 (December 8, 2014): 459–72. http://dx.doi.org/10.2166/wh.2014.313.

Full text

Abstract:

Factors affecting the decay of Salmonella Birkenhead and coliphage, as representatives of bacterial and viral pathogens, respectively, during mesophilic anaerobic digestion (MAD) and air drying treatment of anaerobically digested sewage sludge were investigated. Controlled concentrations of S. Birkenhead were inoculated into non-sterile, autoclaved, γ-irradiated and nutrient-supplemented sludge and cultures were incubated at 37 °C (MAD sludge treatment temperature) or 20 °C (summer air drying sludge treatment temperature). Nutrient limitation caused by microbial competition was the principal mechanism responsible for the decay of S. Birkenhead by MAD and during air drying of digested sludge. The effects of protease activity in sludge on MS2 coliphage decay in digested and air dried sludge were also investigated. MS2 coliphage showed a 3.0–3.5 log10 reduction during incubation with sludge-protease extracts at 37 °C for 25 h. Proteases produced by indigenous microbes in sludge potentially increase coliphage inactivation and may therefore have a significant role in the decay of enteric viruses in sewage sludge. The results help to explain the loss of viability of enteric bacteria and viral pathogens with treatment process time and contribute to fundamental understanding of the various biotic inactivation mechanisms operating in sludge treatment processes at mesophilic and ambient temperatures.

APA, Harvard, Vancouver, ISO, and other styles

25

Weemaes, M., H. Grootaerd, F. Simoens, A. Huysmans, and W. Verstraete. "Ozonation of sewage sludge prior to anaerobic digestion." Water Science and Technology 42, no. 9 (November 1, 2000): 175–78. http://dx.doi.org/10.2166/wst.2000.0199.

Full text

Abstract:

Anaerobic digestion has traditionally been employed to reduce the mass and volume of waste sludge and to enhance the sludge dewaterability. In practice, anaerobic digestion of biosolids has a number of shortcomings, i.e. the low biodegradability of the microbial cells and the high retention times due to the rate limiting hydrolysis step. An oxidative sludge pre-treatment with ozone was therefore used to solubilize the organic compounds and increase their biodegradability. It is shown that the pre-treatment could significantly enhance anaerobic sludge digestion. Moreover, a novel approach in which the sludge was separated in a thickened sediment fraction and a supernatant was investigated. The sediment was digested anaerobically and the supernatant was treated aerobically. The overall COD-removal efficiency of the biosolids was 72%.

APA, Harvard, Vancouver, ISO, and other styles

26

Di Costanzo, Nicola, Alessandra Cesaro, Francesco Di Capua, and Giovanni Esposito. "Exploiting the Nutrient Potential of Anaerobically Digested Sewage Sludge: A Review." Energies 14, no. 23 (December 5, 2021): 8149. http://dx.doi.org/10.3390/en14238149.

Full text

Abstract:

The world is currently witnessing a rapid increase in sewage sludge (SS) production, due to the increased demand for wastewater treatment. Therefore, SS management is crucial for the economic and environmental sustainability of wastewater treatment plants. The recovery of nutrients from SS has been identified as a fundamental step to enable the transition from a linear to a circular economy, turning SS into an economic and sustainable source of materials. SS is often treated via anaerobic digestion, to pursue energy recovery via biogas generation. Anaerobically digested sewage sludge (ADS) is a valuable source of organic matter and nutrients, and significant advances have been made in recent years in methods and technologies for nutrient recovery from ADS. The purpose of this study is to provide a comprehensive overview, describing the advantages and drawbacks of the available and emerging technologies for recovery of nitrogen (N), phosphorus (P), and potassium (K) from ADS. This work critically reviews the established and novel technologies, which are classified by their ability to recover a specific nutrient (ammonia stripping) or to allow the simultaneous recovery of multiple elements (struvite precipitation, ion exchange, membrane technologies, and thermal treatments). This study compares the described technologies in terms of nutrient recovery efficiency, capital, and operational costs, as well as their feasibility for full-scale application, revealing the current state of the art and future perspectives on this topic.

APA, Harvard, Vancouver, ISO, and other styles

27

Logan, Terry J., and Robert E. Feltz. "Plant Uptake of Cadmium from Acid-extracted Anaerobically Digested Sewage Sludge." Journal of Environmental Quality 14, no. 4 (October 1985): 495–500. http://dx.doi.org/10.2134/jeq1985.00472425001400040008x.

Full text

APA, Harvard, Vancouver, ISO, and other styles

28

Yang, Y., Y. Q. Zhao, A. O. Babatunde, and P. Kearney. "Two strategies for phosphorus removal from reject water of municipal wastewater treatment plant using alum sludge." Water Science and Technology 60, no. 12 (December 1, 2009): 3181–88. http://dx.doi.org/10.2166/wst.2009.609.

Full text

Abstract:

In view of the well recognized need of reject water treatment in MWWTP (municipal wastewater treatment plant), this paper outlines two strategies for P removal from reject water using alum sludge, which is produced as by-product in drinking water treatment plant when aluminium sulphate is used for flocculating raw waters. One strategy is the use of the alum sludge in liquid form for co-conditioning and dewatering with the anaerobically digested activated sludge in MWWTP. The other strategy involves the use of the dewatered alum sludge cakes in a fixed bed for P immobilization from the reject water that refers to the mixture of the supernatant of the sludge thickening process and the supernatant of the anaerobically digested sludge. Experimental trials have demonstrated that the alum sludge can efficiently reduce P level in reject water. The co-conditioning strategy could reduce P from 597–675 mg P/L to 0.14–3.20 mg P/L in the supernatant of the sewage sludge while the organic polymer dosage for the conditioning of the mixed sludges would also be significantly reduced. The second strategy of reject water filtration with alum sludge bed has shown a good performance of P reduction. The alum sludge has P-adsorption capacity of 31 mg-P/g-sludge, which was tested under filtration velocity of 1.0 m/h. The two strategies highlight the beneficial utilization of alum sludge in wastewater treatment process in MWWTP, thus converting the alum sludge as a useful material, rather than a waste for landfill.

APA, Harvard, Vancouver, ISO, and other styles

29

Snyman, H. G., P. Forssman, A. Kafaar, and M. Smollen. "The feasibility of electro-osmotic belt filter dewatering technology at pilot scale." Water Science and Technology 41, no. 8 (April 1, 2000): 137–44. http://dx.doi.org/10.2166/wst.2000.0153.

Full text

Abstract:

Sewage sludge is typically dewatered using drying beds, belt filter presses or centrifuges. Mechanical dewatering of sludge is costly in terms of capital and running costs, especially the flocculent. In an attempt to address the need for more cost-effective dewatering technologies, electro-osmotic belt filtering was developed by Smollen and Kafaar in 1995. Themechanical equipment resembles a belt filter press but the belts are stainless steel, woven belts, which act as the electrodes. In this study, thefeasibility of the technology was tested at pilot scale using wasteactivated-, anaerobically digested- and dissolved air flotation sludge. The parameters which were investigated includes the applied voltage, polyelectrolyteusage and sludge feed rate. Applied voltage of between 15 and 25 volts increased the dewatering significantly in the waste activated- and anaerobically digested sludge. Applying a voltage in dissolved air flotation sludge could not enhance the efficiency of dewatering, unless stored to de-air. The technology was found as sensitive to polyelectrolyte dosages as belt presses. The performance of the electro-osmotic belt filter was sensitive to feed rate, but performed well with non-thickened waste activated sludge (0.61% solids), resulting in cake solids above 20%.

APA, Harvard, Vancouver, ISO, and other styles

30

Hashimoto, M., and M. Hiraoka. "Characteristics of Sewage Sludge Affecting Dewatering by Belt Press Filter." Water Science and Technology 22, no. 12 (December 1, 1990): 143–52. http://dx.doi.org/10.2166/wst.1990.0109.

Full text

Abstract:

Dewatering characteristics of sewage sludge were determined by conditioning the sludge with the most effective cationic polyelectrolyte studied, and dewatering using a belt press filter. The characteristics of sludges (16 mixed, and 8 anaerobically digested) were measured for 33 factors affecting dewaterability. The correlations of sludge factors with sludge dewaterability were investigated. The results revealed the following. A factor affecting the gravitational filterability of conditioned sludge is the suspended solids concentration of raw sludge. A factor affecting the moisture content of dewatered sludge cake is viscosity of the sludge adjusted to 4.0 % of suspended solids concentration. Factors affecting the viscosity are the intrinsic viscosity of alkaline extracts, the ratio of (VSS-Fiber)/SS : Ash/SS : Fiber/SS, and the charge density of sludge particles. A factor affecting the extension degree of dewatered sludge cake is the charge density of sludge particles. Factors affecting the amount of residual solids on the filter cloths are the charge density of sludge particles and the fibrous substances content of sludge. As for polyelectrolytes, a highly cationized polyelectrolyte is effective to lower the moisture content, the extension degree and the amount of residual solids on filter cloths. And a factor affecting the required dosage of a polyelectrolyte is anionic substances content in the liquid of raw sludge.

APA, Harvard, Vancouver, ISO, and other styles

31

Murugesan, Kumarasamy, Balasubramani Ravindran, Ammaiyappan Selvam, Mayur B. Kurade, Shuk-Man Yu, and Jonathan W. C. Wong. "Enhanced dewaterability of anaerobically digested sewage sludge using Acidithiobacillus ferrooxidans culture as sludge conditioner." Bioresource Technology 169 (October 2014): 374–79. http://dx.doi.org/10.1016/j.biortech.2014.06.057.

Full text

APA, Harvard, Vancouver, ISO, and other styles

32

Prodanović, Jelena, Marina Šćiban, and Mirjana Antov. "Improvement of wastewater treatment by use of natural coagulants." Journal of Economic Development, Environment and People 2, no. 2 (June 22, 2013): 22. http://dx.doi.org/10.26458/jedep.v2i2.20.

Full text

Abstract:

An activated sludge and other organic sludges from wastewater treatment processes are usually anaerobically digested prior to application on land. The purpose of digestion is to convert bulky, odorous sludges to relatively inert material that can be rapidly dewatering. The important benefit of this process is a biogas production, too. It is proper to enlarge primary sludge production in a primary settler by adding some coagulation aids, with aim to increase a biogas production, as much as possible. The most common coagulant is alum, but presence of large quantities of aluminum salts in sludge has a harmful impact on digestion and digested sludge application. Some natural coagulants, that have a numerous advantages, can be used instead of alum. Natural coagulants could be extracted from a different plant material, and considering the fact that they are of organic nature, the biogas yield can be enhanced by their presence. A plant material that remains after extraction can be used as a feed. The aim of this paper is a consideration of potential environmental benefits of substitution of alum by natural coagulant extracted from common bean seeds in sewage wastewater treatment process.

APA, Harvard, Vancouver, ISO, and other styles

33

Kong, Frederic E., Margaret A. Deighton, Nerida A. Thurbon, Stephen R. Smith, and Duncan A. Rouch. "Cryptosporidium parvum decay during air drying and stockpiling of mesophilic anaerobically digested sewage sludge in a simulation experiment and oocyst counts in sludge collected from operational treatment lagoons in Victoria, Australia." Journal of Water and Health 16, no. 3 (April 5, 2018): 435–48. http://dx.doi.org/10.2166/wh.2018.018.

Full text

Abstract:

Abstract The inactivation of Cryptosporidium species oocysts during sewage sludge treatment is important to protect human health when the residual biosolids are applied to agricultural land. Quantifying the decay of Cryptosporidium species during sludge treatment for microbiological assurance purposes is difficult if low numbers are present in wastewater. The rate of decay of Cryptosporidium parvum oocysts during solar/air drying treatment and in sludge stockpiles in temperate environment conditions was simulated in laboratory inoculation experiments using sludge sampled from a mesophilic anaerobic digester. Oocyst numbers were also determined in settled lagoon sludge samples collected from three operational rural wastewater treatment plants (WWTPs). C. parvum oocysts were enumerated by immunomagnetic separation followed by staining with vital dyes and examination by confocal laser scanning microscopy. An air-drying/storage period equivalent to 11 weeks was required for a 1 log10 reduction of viable oocysts inoculated into digested sludge. Oocyst viability in air-dried and stored digested sludge decreased with time, but was independent of sludge desiccation and dry solids (DS) content. No oocysts were detected in sludge samples collected from the anaerobic digester, and the average concentration of oocysts found in settled lagoon sludge from the rural WWTP was 4.6 × 102 oocysts/g DS.

APA, Harvard, Vancouver, ISO, and other styles

34

Stadterman, K. L., A. M. Sninsky, J. L. Sykora, and W. Jakubowskii. "Removal and inactivation of cryptosporidium oocysts by activated sludge treatment and anaerobic digestion." Water Science and Technology 31, no. 5-6 (March 1, 1995): 97–104. http://dx.doi.org/10.2166/wst.1995.0572.

Full text

Abstract:

To determine the fate of Cryptosporidium parvum oocysts during wastewater treatment, a model of an activated sludge treatment plant was designed with a flow of 17 ml/min and a detention time of 6 hours. Samples of raw sewage were seeded with oocysts and primary and secondary effluents were analyzed for C. parvum using an immunofluorescent technique. To compare removal efficiencies of oocysts by various wastewater treatment processes, raw sewage, activated sludge, trickling filter and biodisc effluents were seeded with oocysts and settled for 2 hr and for the respective detention times. Sludge produced by a wastewater treatment plant and anaerobically digested at 37° C in a laboratory digester was also seeded with C. parvum oocysts. Oocyst inactivation was measured by excystation and direct counts. Removal of oocysts in primary and secondary sedimentation averaged 83.4% and 90.7% respectively. The total oocyst removal in sewage treatment averaged 98.6%. In comparison with other treatment processes, activated sludge had the maximum oocyst removal efficiency at 92%. The anaerobic digestion process inactivated 90% of the oocysts within four hours of exposure. 99.9% of the oocysts were eliminated by anaerobic digestion after 24 hours. This demonstrates that the activated sludge process and anaerobic digestion can be effective for the removal and inactivation of C. parvum oocysts.

APA, Harvard, Vancouver, ISO, and other styles

35

Zouboulis, A. I., P. Solari, K. A. Matis, and G. A. Stalidis. "Toxic metals removal from dilute solutions by biosorptive flotation." Water Science and Technology 32, no. 9-10 (November 1, 1995): 211–20. http://dx.doi.org/10.2166/wst.1995.0687.

Full text

Abstract:

Toxic metal ions (cadmium, nickel and zinc), considered as priority pollutants, were removed from dilute aqueous solutions by sorption onto non-living (sterilized) anaerobically digested sewage sludge. The desorption of cadmium from metal-laden sludge was also examined. Flotation was subsequently applied as an effective solid/liquid separation process. The dissolved-air flotation technique was applied for the generation of fine bubbles and, in parallel, electrokinetic measurements were carried out. Promising results were succeeded from the combined process of biosorption/flotation (termed biosorptive flotation).

APA, Harvard, Vancouver, ISO, and other styles

36

Straub, Timothy M., Ian L. Pepper, and Charles P. Gerba. "Persistence of Viruses in Desert Soils Amended with Anaerobically Digested Sewage Sludge." Applied and Environmental Microbiology 58, no. 2 (1992): 636–41. http://dx.doi.org/10.1128/aem.58.2.636-641.1992.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

Strasser, Hermann, Herbert Brunner, and Franz Schinner. "Leaching of iron and toxic heavy metals from anaerobically-digested sewage sludge." Journal of Industrial Microbiology 14, no. 3-4 (March 1995): 281–87. http://dx.doi.org/10.1007/bf01569940.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Özçimen, Didem, and Tufan Salan. "Removal of reactive dye Remazol Brilliant Blue R from aqueous solutions by using anaerobically digested sewage sludge based adsorbents." Chemical Industry and Chemical Engineering Quarterly 22, no. 2 (2016): 167–79. http://dx.doi.org/10.2298/ciceq141128029o.

Full text

Abstract:

In this study, adsorbents were produced from sewage sludge via chemical and thermal activation processes. Experiments were carried out in a tubular furnace at the heating rate of 20?C min-1 and temperature of 550 ?C with a nitrogen flow rate of 400 mL min-1 for 1 h. Dye adsorption experiments were performed with Remazol Brilliant Blue R for its several concentrations under batch equilibrium conditions by comparing sewage sludge based adsorbents with raw material and a commercial activated carbon. Maximum adsorption capacities of carbonized sewage sludge (CSWS) and activated sewage sludge (ASWS) were found as 7.413 mg g-1 and 9.376 mg g-1 for 100 mg L-1 dye solution, whereas commercial activated carbon had a capacity of 11.561 mg g-1. Freundlich and Langmuir isotherms were used to explain the adsorption mechanism together with pseudo-first-order and pseudo-second-order kinetic models. Langmuir isotherm, which had adsorption capacities of 34.60 mg g-1 (CSWS) and 72.99 mg g-1 (ASWS), provided better fit to the equilibrium data than that of Freundlich isotherm. Pseudo second-order, model which had adsorption capacities of 7.451 mg g-1 (CSWS) and 9.319 mg g-1 (ASWS), was very favorable to explain the adsorption kinetics of the dye with high regression coefficients.

APA, Harvard, Vancouver, ISO, and other styles

39

Liu, Yuan, Jie Jin, Jiawei Li, Ziwei Zou, Renchan Lei, Jintao Sun, and Jinxia Xia. "Enhanced Phosphorus Recovery as Vivianite from Anaerobically Digested Sewage Sludge with Magnetic Biochar Addition." Sustainability 14, no. 14 (July 15, 2022): 8690. http://dx.doi.org/10.3390/su14148690.

Full text

Abstract:

Sustainable phosphorus (P) recovery from sewage sludge is crucial to reconciling the simultaneous shortage and excess of P. In this study, magnetic biochar (MBC) was synthesized and innovatively applied to enhance P recovery as vivianite. The effects of anaerobic digestion (AD) time, hydrothermal (HT) pretreatment temperature and MBC dose on vivianite formation were investigated using batch experiments and a modified sequential P extraction protocol. The P fractionation results showed that the concentration of pure vivianite-bound P (Fe(II)-P) reached a maximum on the 10th day of AD treatment, and then declined sharply due to vivianite oxidation and P limitation. HT pretreatment operated at relatively high temperatures (135 and 185 °C) reduced vivianite formation; this negative effect of HT pretreatment was partially compensated by MBC supplementation. The proportion of Fe(II)-P in the solid phase of sludge was substantially raised up to 57.1% from 8.3~17.4% with an increasing dose of MBC from 0 to 12.5 g/L, indicating that MBC had a markedly enhanced effect on vivianite formation; this could be attributed to the MBC-improved Fe(II) production, as evidenced by the elevated proportion of Fe(II) in Fe2p XPS spectra and the increased ratio of Fe(II)-P to oxidized vivianite-bound P (Fe(III)-P) in the sludge after MBC supplementation. MBC addition also decreased the proportion of water-extractable P by sorption and promoted organic P decomposition, which further facilitated vivianite production. These findings reveal a new strategy for enhancing P recovery from HT-pretreated AD sludge.

APA, Harvard, Vancouver, ISO, and other styles

40

EDGAR, K. F., D. A. KLESSA, J. FRAME, and R. D. HARKESS. "The nitrogen value of anaerobically digested sewage sludge applied to grassland during winter." Grass and Forage Science 50, no. 4 (December 1995): 353–64. http://dx.doi.org/10.1111/j.1365-2494.1995.tb02330.x.

Full text

APA, Harvard, Vancouver, ISO, and other styles

41

Rincón, Carlos Andrés, Amaury De Guardia, Annabelle Couvert, Isabelle Soutrel, Stevan Guezel, and Camille Le Serrec. "Odor generation patterns during different operational composting stages of anaerobically digested sewage sludge." Waste Management 95 (July 2019): 661–73. http://dx.doi.org/10.1016/j.wasman.2019.07.006.

Full text

APA, Harvard, Vancouver, ISO, and other styles

42

Ito, Ayumi, Teruyuki Umita, Jiro Aizawa, and Kumiko Kitada. "Effect of inoculation of iron oxidizing bacteria on elution of copper from anaerobically digested sewage sludge." Water Science and Technology 38, no. 2 (July 1, 1998): 63–70. http://dx.doi.org/10.2166/wst.1998.0105.

Full text

Abstract:

The effect of inoculation of iron oxidizing bacteria on elution of Cu from anaerobically digested sewage sludge was investigated without adding ferrous sulfate as a substrate. The inoculation of iron oxidizing bacteria to the sludge brought about the effective elution of Cu at pH 2 and 3. Ferric ion produced by the biological oxidation of ferrous ion which was eluted from the sludge or ferric ion eluted directly from the sludge and iron oxidizing bacteria caused the elution of Cu. Furthermore, both chemical and biological leachings of Cu from CuS were studied at pH 2, 3 and 4. It was found that both ferric ion and iron oxidizing bacteria could elute Cu. The elution rate of Cu with ferric ion decreased as the pH increased and two moles of Fe(III) eluted 1 mole of Cu. The biological leaching by iron oxidizing bacteria eluted Cu more effectively than the chemical one with sulfuric acid or ferric sulfate at pH 2, 3 and 4.

APA, Harvard, Vancouver, ISO, and other styles

43

Straub, Timothy M., Ian L. Pepper, and Charles P. Gerba. "Virus Survival in Sewage Sludge Amended Desert Soil." Water Science and Technology 27, no. 3-4 (February 1, 1993): 421–24. http://dx.doi.org/10.2166/wst.1993.0384.

Full text

Abstract:

Currently Pima County, Arizona, disposes all of its anaerobically digested sewage sludge in liquid form (1.5% solids) on agricultural land used for non-food crop production by subsurface injection or surface spreading. Present in these sludges are human enteric viruses in concentrations as high as 1,000 per liter of sludge. These viruses could potentially contaminate surface and groundwater sources during periods of irrigation or extended rainfall. This study was designed to assess the survival of viruses under field conditions typical of the arid Southwestern United States during the winter and summer months. This study was also conducted in the laboratory to simulate field conditions. Soil samples taken from freshly amended fields were seeded with poliovirus type 1 (stock titer = 106/ml) and bacteriophage MS-2 (stock titer = 1010/ml)and thoroughly mixed with the sludged soil. The seeded samples were put into containers and buried 10 cm below the soil surface, and samples were taken at pre-determined time intervals. Average soil temperature (measured at the 10 cm depth) ranged from 15°C in the winter to 33°C in the summer. Soil moisture decreased from 25% to 15% in the winter and from 40% to less than 5 % in the summer. During the winter study, no inactivation of poliovirus was observed after 7 days, while greater than a 90% reduction was observed for MS-2. During the summer study, no poliovirus was recovered after 7 days, and no MS-2 was recovered after 3 days. The results of this study suggest that high soil temperature and rapid loss of moisture limit the survival of viruses in desert soils.

APA, Harvard, Vancouver, ISO, and other styles

44

Bennie, Donald T. "Review of the Environmental Occurrence of Alkylphenols and Alkylphenol Ethoxylates." Water Quality Research Journal 34, no. 1 (February 1, 1999): 79–122. http://dx.doi.org/10.2166/wqrj.1999.004.

Full text

Abstract:

Abstract Alkylphenol ethoxylates and, in particular, nonylphenol ethoxylates have found many industrial, commercial, institutional and household uses in Canada. These nonionic surfactants are very efficient and cost effective. Their widespread use has led to the detection of the parent surfactants and their degradation products in various environmental matrices. Alkylphenol ethoxylates can be degraded aerobically and anaerobically in natural environments and sewage treatment plants.. The resulting degradation products are more persistent, more toxic, more lipophilic, less water soluble and more estrogenic than their parent compounds. This article reviews the occurrence of nonylphenol polyethoxylates and their degradation products as well as octylphenol poly-ethoxylates and their degradation products. There is limited information available about the concentrations of these substances in their original product formulations. The highest levels of the degradation products, especially nonylphenol, occur in the anaerobically digested sludge of sewage treatment plants. Sludge from these sewage treatment plants may be used as an amendment to agricultural soils. Various sewage treatment plants have wide ranges of discharged effluent concentrations of these compounds — some appear to be very efficient at removing alkylphenolics from their effluent stream. Little information is available about the fate of these substances in their receiving environment, and environmental concentrations and bioaccumulation factors of these contaminants in aquatic biota. More research is required on the uptake, persistence and bioaccumulation of alkylphenolic metabolites in fish, mussels and other aquatic organisms

APA, Harvard, Vancouver, ISO, and other styles

45

Choi, Hyoyoung, Junghyeon Kim, Sujin Lee, and Imgyu Byun. "Improving the Dewaterability of a Filter Press through Optimization of the Coagulation Conditions of Sewage Sludge." Journal of the Korean Society of Hazard Mitigation 23, no. 1 (February 28, 2023): 217–23. http://dx.doi.org/10.9798/kosham.2023.23.1.217.

Full text

Abstract:

This study applied a filter press for dewatering that uses pressure to reduce the water content of sludge generated in sewage treatment plants and evaluated the improvement of dewaterability under various coagulation conditions according to the type of coagulants, amounts, and pH conditions. The improvement of dewaterability was evaluated by measurement of time to filter (TTF), change in zeta potential, and sludge cake generated after filter press dewatering. It was found that under the applied coagulation conditions, inorganic coagulants were suitable for filter press dewatering. The optimum conditions were PAC with a dose of 70 mg/gTS, pH 10 for mixed sludge, and PAC with a dose of 100 mg/gTS, pH 6 for anaerobically digested sludge. Under optimal coagulation conditions, the water content of the sludge cake was 57% and 65%, respectively, marking a reduction by 19-27% compared to conventional centrifuge dewatering.

APA, Harvard, Vancouver, ISO, and other styles

46

Baham, John, and Garrison Sposito. "Proton and Metal Complexation by Water-soluble Ligands Extracted from Anaerobically Digested Sewage Sludge." Journal of Environmental Quality 15, no. 3 (July 1986): 239–44. http://dx.doi.org/10.2134/jeq1986.00472425001500030007x.

Full text

APA, Harvard, Vancouver, ISO, and other styles

47

Gu, Xiangyang, and Jonathan W. C. Wong. "Identification of Inhibitory Substances Affecting Bioleaching of Heavy Metals from Anaerobically Digested Sewage Sludge." Environmental Science & Technology 38, no. 10 (May 2004): 2934–39. http://dx.doi.org/10.1021/es0347134.

Full text

APA, Harvard, Vancouver, ISO, and other styles

48

Ek, M., R. Bergström, J. E. Bjurhem, B. Björlenius, and D. Hellström. "Concentration of nutrients from urine and reject water from anaerobically digested sludge." Water Science and Technology 54, no. 11-12 (December 1, 2006): 437–44. http://dx.doi.org/10.2166/wst.2006.924.

Full text

Abstract:

Experiments with concentration of nutrients from source separated urine and reject water from digestion of sludge in sewage treatment plants (STP) have been performed in laboratory and pilot scale. The methods tested were membrane filtration with reverse osmosis (RO), evaporation, and precipitation of phosphorus and distillation of ammonia. In membrane filtration, pre-filtration with particle separation at 5–10 μm was enough to avoid clogging of the membranes. Separation of phosphorus (P), potassium (K) and sulphur (S) was almost 100%, while separation of nitrogen (N) was dependent on pH. The capacity of flux increased with temperature and pressure. In evaporation, all P, K and S were still in the concentrate, while pH had to be decreased to 4.5 to avoid significant loss of N. In precipitation and distillation, about 90% of P could be recovered from urine as magnesium ammonium phosphate (MAP) just by adding MgO. For the reject water pH was first increased by aeration to remove CO2. Ammonium can be distilled from the water phase after precipitation of MAP, without further increase of pH. At least 80–90% of N can be distilled in 5–10% of the total volume. The article also discusses the quality of different products, cost of separation, and energy and chemical demand.

APA, Harvard, Vancouver, ISO, and other styles

49

Nurul Islam, A. K. M., Keisuke Hanaki, and Tomonori Matsuo. "Fate of dissolved odorous compounds in sewage treatment plants." Water Science and Technology 38, no. 3 (August 1, 1998): 337–44. http://dx.doi.org/10.2166/wst.1998.0229.

Full text

Abstract:

The concentration of selected malodorous compounds dissolved in water in different unit processes of actual treatment plant, and in different location of small scale treatment plants (Jokasos) were identified in order to provide sufficient information to undertake proper action to solve the problems of malodor compounds in water environment and in wastewater reuse. Analytic methods to measure as low as mg/l level of 16 odorous compounds were developed. In total, four sewerage treatment plants, three sludge treatment plants and six Jokasos were surveyed. Treatment plants were chosen in a way so that most types of unit processes could be covered. Being exposed to anaerobic condition is the primary reason of production of odorous compounds. As far as the secondary treatment is operated properly, odorous compounds concentration in the effluent can be maintained below odor threshold concentration. Odorous compounds were produced during sludge treatment process while the sludge is sedimented, thickened and dewatered, or anaerobically digested. A new way to express the odor concentration is proposed to obtain quick and comprehensive visualization of odor intensity.

APA, Harvard, Vancouver, ISO, and other styles

50

Olofsson, U., S. Lundstedt, and P. Haglund. "Behavior and fate of anthropogenic substances at a Swedish sewage treatment plant." Water Science and Technology 62, no. 12 (December 1, 2010): 2880–88. http://dx.doi.org/10.2166/wst.2010.987.

Full text

Abstract:

The behavior and fate of anthropogenic substances during sewage treatment were investigated at a sewage treatment plant (STP) in Sweden which uses mechanical, chemical, and biological methods for sewage treatment and anaerobic digestion of sludge. Influent and effluent water, and sludge from two specific treatment sites were sampled. Mass balances were calculated from measured concentrations of various substances and estimates of the mass flows (water, solids) throughout the process. The results show that the metals (As, Cd, Cr, Hg, Pb) and the majority of PCBs, PCDD/Fs, and PBDEs enter and leave the STP bound to particles. Triclosan and di-(2-ethylhexyl)phthalate adsorb to sludge to a high degree, while the metals (Co, Cu, Ni, Zn) and organophosphate esters seem to pass through the STP unaffected by the process. Generally, the STP was better in removing lipophilic than water soluble compounds. Most of the substances end up in anaerobically digested sludge in almost the same concentrations as in primary sludge. A fugacity based STP model was evaluated for its ability to predict the behavior and fate of the substances and was found feasible for lipophilic compounds. It did however produce poor predictions for water soluble compounds such as organophosphate esters (overestimated) and antibacterial agents (underestimated).

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Sewage sludge anaerobically digested'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles