51
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Zhang Q, Zhang Z, Teng J, Huang H, Peng Q, Jiao T, Hou L, Li B. Highly Efficient Phosphate Sequestration in Aqueous Solutions Using Nanomagnesium Hydroxide Modified Polystyrene Materials. Ind Eng Chem Res 2015. [DOI: 10.1021/ie503943z] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
| | | | | | | | | | | | | | - Bingbing Li
- Department of Chemistry and Biochemistry,
Science of Advanced Materials, Central Michigan University, Mt. Pleasant, Michigan 48858, United States
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52
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Hu C, Chen Q, Chen G, Liu H, Qu J. Removal of Se(IV) and Se(VI) from drinking water by coagulation. Sep Purif Technol 2015. [DOI: 10.1016/j.seppur.2014.12.028] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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53
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Application of QUAL2K model to assess ecological purification technology for a polluted river. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2015; 12:2215-29. [PMID: 25689997 PMCID: PMC4344721 DOI: 10.3390/ijerph120202215] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 02/04/2015] [Indexed: 11/19/2022]
Abstract
Industrialization and urbanization have caused water pollution and ecosystem degradation, especially in urban canals and rivers in China; accordingly, effective water quality improvement programs are needed. In this study, the Tianlai River in Jiangsu, China was taken as a research site, and a combination of ecological purification technologies consisting of biological rope, phytoremediation, and activated carbon were applied in a laboratory-scale study to examine degradation coefficients under dynamic water conditions. Coefficients were then input into the QUAL2K model to simulate various hypothetical scenarios and determine the minimum density of ecological purification combination and hydraulic retention time (HRT) to meet Grade V or IV of the China standard for surface water. The minimum densities for Grade V and IV were 1.6 times and 2 times the experimental density, while the minimum HRTs for Grade V and IV were 2.4 day and 3 day. The results of this study should provide a practical and efficient design method for ecological purification programs.
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54
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Huang H, Xiao D, Zhang Q, Ding L. Removal of ammonia from landfill leachate by struvite precipitation with the use of low-cost phosphate and magnesium sources. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2014; 145:191-8. [PMID: 25043172 DOI: 10.1016/j.jenvman.2014.06.021] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Revised: 06/18/2014] [Accepted: 06/24/2014] [Indexed: 05/22/2023]
Abstract
This paper presents a study concerning ammonia removal from landfill leachate by struvite precipitation with the use of waste phosphoric acid as the phosphate source. The results indicated that the Al(3+) ions present in the waste phosphoric acid significantly affected the struvite precipitation, and a removal ratio of ammonia close to that of pure phosphate salts could be achieved. Nevertheless, large amounts of NaOH were necessary to neutralize the H(+) present in the waste phosphoric acid. To overcome this problem, a low-cost magnesium source was proposed to be used as well as an alkali reagent in the struvite precipitation. The ammonia removal ratios were found to be 83%, with a remaining phosphate of 56 mg/L, by dosing the low-cost MgO in the Mg:N:P molar ratio of 3:1:1. An economic analysis showed that using waste phosphoric acid plus the low-cost MgO could save chemical costs by 68% compared with the use of pure chemicals. Post-treatment employment of a biological anaerobic filter process demonstrated that the high concentration of Mg(2+) remaining in the effluent of the struvite precipitation has no inhibitory effect on the performance of the biological treatment.
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Affiliation(s)
- Haiming Huang
- Hebei Key Laboratory of Applied Chemistry, School of Environmental and Chemical Engineering, Yanshan University, Qinhuangdao, Hebei 066004, PR China.
| | - Dean Xiao
- Environmental Monitoring Center of Guizhou Province, Guiyang 550081, PR China
| | - Qingrui Zhang
- Hebei Key Laboratory of Applied Chemistry, School of Environmental and Chemical Engineering, Yanshan University, Qinhuangdao, Hebei 066004, PR China
| | - Li Ding
- Hebei Key Laboratory of Applied Chemistry, School of Environmental and Chemical Engineering, Yanshan University, Qinhuangdao, Hebei 066004, PR China
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55
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Lee KE, Morad N, Teng TT, Poh BT. Reactive Dye Removal Using Inorganic–Organic Composite Material: Kinetics, Mechanism, and Optimization. J DISPER SCI TECHNOL 2014. [DOI: 10.1080/01932691.2013.867272] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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56
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Zhao S, Gao B, Yue Q, Wang Y, Li Q, Dong H, Yan H. Study of Enteromorpha polysaccharides as a new-style coagulant aid in dye wastewater treatment. Carbohydr Polym 2014; 103:179-86. [DOI: 10.1016/j.carbpol.2013.12.045] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2013] [Revised: 12/02/2013] [Accepted: 12/13/2013] [Indexed: 11/28/2022]
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57
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Liu Y, Zhang W, Yang X, Xiao P, Wang D, Song Y. Advanced treatment of effluent from municipal WWTP with different metal salt coagulants: Contaminants treatability and floc properties. Sep Purif Technol 2013. [DOI: 10.1016/j.seppur.2013.09.046] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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58
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Wang Y, Chen K, Mo L, Li J. Pretreatment of papermaking-reconstituted tobacco slice wastewater by coagulation-flocculation. J Appl Polym Sci 2013. [DOI: 10.1002/app.39278] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Yufeng Wang
- State Key Lab of Pulp and Paper Engineering; South China University of Technology; Guangzhou 510640 China
- United Lab of Resource Chemistry and Chemical Engineering; Guangzhou 510640 China
| | - Kefu Chen
- State Key Lab of Pulp and Paper Engineering; South China University of Technology; Guangzhou 510640 China
- United Lab of Resource Chemistry and Chemical Engineering; Guangzhou 510640 China
| | - Lihuan Mo
- State Key Lab of Pulp and Paper Engineering; South China University of Technology; Guangzhou 510640 China
- United Lab of Resource Chemistry and Chemical Engineering; Guangzhou 510640 China
| | - Jun Li
- State Key Lab of Pulp and Paper Engineering; South China University of Technology; Guangzhou 510640 China
- United Lab of Resource Chemistry and Chemical Engineering; Guangzhou 510640 China
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59
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Bazrafshan E, Kord Mostafapour F, Farzadkia M, Ownagh KA, Mahvi AH. Slaughterhouse wastewater treatment by combined chemical coagulation and electrocoagulation process. PLoS One 2012; 7:e40108. [PMID: 22768233 PMCID: PMC3387025 DOI: 10.1371/journal.pone.0040108] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Accepted: 06/01/2012] [Indexed: 12/07/2022] Open
Abstract
Slaughterhouse wastewater contains various and high amounts of organic matter (e.g., proteins, blood, fat and lard). In order to produce an effluent suitable for stream discharge, chemical coagulation and electrocoagulation techniques have been particularly explored at the laboratory pilot scale for organic compounds removal from slaughterhouse effluent. The purpose of this work was to investigate the feasibility of treating cattle-slaughterhouse wastewater by combined chemical coagulation and electrocoagulation process to achieve the required standards. The influence of the operating variables such as coagulant dose, electrical potential and reaction time on the removal efficiencies of major pollutants was determined. The rate of removal of pollutants linearly increased with increasing doses of PACl and applied voltage. COD and BOD5 removal of more than 99% was obtained by adding 100 mg/L PACl and applied voltage 40 V. The experiments demonstrated the effectiveness of chemical and electrochemical techniques for the treatment of slaughterhouse wastewaters. Consequently, combined processes are inferred to be superior to electrocoagulation alone for the removal of both organic and inorganic compounds from cattle-slaughterhouse wastewater.
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Affiliation(s)
- Edris Bazrafshan
- Health Promotion Research Center, Zahedan University of Medical Sciences, Zahedan, Iran
| | | | - Mehdi Farzadkia
- School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Kamal Aldin Ownagh
- Health Promotion Research Center, Zahedan University of Medical Sciences, Zahedan, Iran
| | - Amir Hossein Mahvi
- School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
- Center for Solid Waste Research, Institute for Environmental Research, Tehran University of Medical Sciences, Tehran, Iran
- National Institute of Health Research, Tehran University of Medical Sciences, Tehran, Iran
- * E-mail:
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60
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Lacasa E, Cañizares P, Llanos J, Rodrigo MA. Effect of the cathode material on the removal of nitrates by electrolysis in non-chloride media. JOURNAL OF HAZARDOUS MATERIALS 2012; 213-214:478-484. [PMID: 22387000 DOI: 10.1016/j.jhazmat.2012.02.034] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2011] [Revised: 01/12/2012] [Accepted: 02/13/2012] [Indexed: 05/31/2023]
Abstract
In this work, the effect of the cathode material (conductive diamond, stainless steel, silicon carbide, graphite or lead) and the current density (150-1400 A m(-2)) on the removal of nitrates from aqueous solutions is studied by electrolysis in non-divided electrochemical cells equipped with conductive diamond anodes, using sodium sulphate as the electrolyte. The results show that the cathode material very strongly influences both the process performance and the product distribution. The main products obtained are gaseous nitrogen (NO, N(2)O and NO(2)) and ammonium ions. Nitrate removal follows first order kinetics, which indicates that the electrolysis process is controlled by mass transfer. Furthermore, the stainless steel and graphite cathodes show a great selectivity towards the production of ammonium ions, whereas the silicon carbide cathode leads to the highest formation of gaseous nitrogen, which production is promoted at low current densities.
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Affiliation(s)
- Engracia Lacasa
- Department of Chemical Engineering, Faculty of Chemical Sciences, University of Castilla-la Mancha, Avda. Camilo José Cela, 12. 13071 Ciudad Real, Spain
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61
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Vedrenne M, Vasquez-Medrano R, Prato-Garcia D, Frontana-Uribe BA, Ibanez JG. Characterization and detoxification of a mature landfill leachate using a combined coagulation-flocculation/photo Fenton treatment. JOURNAL OF HAZARDOUS MATERIALS 2012; 205-206:208-15. [PMID: 22244343 DOI: 10.1016/j.jhazmat.2011.12.060] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2011] [Revised: 12/15/2011] [Accepted: 12/21/2011] [Indexed: 05/15/2023]
Abstract
The aim of the present work was to characterize and treat a mature landfill leachate using a coagulation/flocculation process followed by a photo-Fenton oxidation treatment. The leachate was obtained from a landfill in Tetlama, Morelos (Mexico) during the drought season and was characterized in terms of its major pollutants. Considerable levels of chemical oxygen demand (COD), total carbon (TC) and NH4+ were identified, as well as high concentrations of Hg, Pb, and As. Other heavy metals such as Ni, Co, Zn, Cd, and Mn were detected at trace levels. The lethal concentration (LC50) of the leachate, evaluated on Artemia salina, was 12,161±11 mg/L of COD, demonstrating an antagonistic interaction among the leachate's components. The treatment of this effluent consisted of a coagulation-flocculation process using an optimal dose of FeCl3 · 6H2O of 300 mg/L. The supernatant was treated using a photo-Fenton process mediated with FeCl2 · 4H2O and H2O2 in a compound parabolic concentrator (CPC) photo-reactor operating in batch mode using an R ratio (R=[H2O2]/[Fe2+]) of 114. The global removal efficiencies after treatment were 56% for the COD, 95% for TC, and 64% for NH4+. The removal efficiencies for As, Hg, and Pb were 46%, 9%, and 85%, respectively.
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Affiliation(s)
- Michel Vedrenne
- Department of Chemistry & Chemical Engineering, Universidad Iberoamericana, Mexico City, Prolongación Paseo de la Reforma 880, Col. Lomas de Santa Fe. 01219 Mexico, DF Mexico
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62
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Phosphorus Removal from Wastewater Using Oven-Dried Alum Sludge. INTERNATIONAL JOURNAL OF CHEMICAL ENGINEERING 2012. [DOI: 10.1155/2012/125296] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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63
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Rittmann BE, Mayer B, Westerhoff P, Edwards M. Capturing the lost phosphorus. CHEMOSPHERE 2011; 84:846-53. [PMID: 21377188 DOI: 10.1016/j.chemosphere.2011.02.001] [Citation(s) in RCA: 209] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2010] [Revised: 01/26/2011] [Accepted: 02/01/2011] [Indexed: 05/18/2023]
Abstract
Minable phosphorus (P) reserves are being depleted and will need to be replaced by recovering P that currently is lost from the agricultural system, causing water-quality problems. The largest two flows of lost P are in agricultural runoff and erosion (∼46% of mined P globally) and animal wastes (∼40%). These flows are quite distinct. Runoff has a very high volumetric flow rate, but a low P concentration; animal wastes have low flow rates, but a high P concentration together with a high concentration of organic material. Recovering the lost P in animal wastes is technically and economically more tractable, and it is the focus for this review of promising P-capture technologies. P capture requires that organic P be transformed into inorganic P (phosphate). For high-strength animal wastes, P release can be accomplished in tandem with anaerobic treatment that converts the energy value in the organic matter to CH(4), H(2), or electricity. Once present as phosphate, the P can be captured in a reusable form by four approaches. Most well developed is precipitation as magnesium or calcium solids. Less developed, but promising are adsorption to iron-based adsorbents, ion exchange to phosphate-selective solids, and uptake by photosynthetic microorganisms or P-selective proteins.
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Affiliation(s)
- Bruce E Rittmann
- Swette Center for Environmental Biotechnology, Biodesign Institute at Arizona State University, PO Box 875701, Tempe, AZ 85287-5701, USA.
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64
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Tzfati E, Sein M, Rubinov A, Raveh A, Bick A. Pretreatment of wastewater: optimal coagulant selection using Partial Order Scaling Analysis (POSA). JOURNAL OF HAZARDOUS MATERIALS 2011; 190:51-59. [PMID: 21561709 DOI: 10.1016/j.jhazmat.2011.02.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Revised: 01/02/2011] [Accepted: 02/08/2011] [Indexed: 05/30/2023]
Abstract
Jar-test is a well-known tool for chemical selection for physical-chemical wastewater treatment. Jar test results show the treatment efficiency in terms of suspended matter and organic matter removal. However, in spite of having all these results, coagulant selection is not an easy task because one coagulant can remove efficiently the suspended solids but at the same time increase the conductivity. This makes the final selection of coagulants very dependent on the relative importance assigned to each measured parameter. In this paper, the use of Partial Order Scaling Analysis (POSA) and multi-criteria decision analysis is proposed to help the selection of the coagulant and its concentration in a sequencing batch reactor (SBR). Therefore, starting from the parameters fixed by the jar-test results, these techniques will allow to weight these parameters, according to the judgments of wastewater experts, and to establish priorities among coagulants. An evaluation of two commonly used coagulation/flocculation aids (Alum and Ferric Chloride) was conducted and based on jar tests and POSA model, Ferric Chloride (100 ppm) was the best choice. The results obtained show that POSA and multi-criteria techniques are useful tools to select the optimal chemicals for the physical-technical treatment.
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Affiliation(s)
- Eran Tzfati
- Department of Chemical Engineering, Shenkar College of Engineering and Design, 12 Anna Frank street, Ramat Gan 52526, Israel.
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65
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Luo YL, Yang ZH, Xu ZY, Zhou LJ, Zeng GM, Huang J, Xiao Y, Wang LK. Effect of trace amounts of polyacrylamide (PAM) on long-term performance of activated sludge. JOURNAL OF HAZARDOUS MATERIALS 2011; 189:69-75. [PMID: 21367524 DOI: 10.1016/j.jhazmat.2011.01.115] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2010] [Revised: 01/29/2011] [Accepted: 01/31/2011] [Indexed: 05/30/2023]
Abstract
This study aims at evaluating the impacts of PAM addition on activated sludge performance. Four lab-scale sequencing batch reactors (SBRs), each with a working volume of 3L, were investigated with different PAM concentrations. Experiments were conducted with varying organic loading rate and the sludge volume index (SVI), particle size, zeta potential, specific oxygen uptake rate (SOUR), mixed liquor suspended solids (MLSS), COD and ammonium removal efficiency were monitored over a 105-day period. The results showed that all of the PAM addition not only improved the removal efficiencies of COD and ammonium, but also exhibited some advantages on sludge performance. It was found that the sludge performance of settling property, flocculation and microbial activity increased with increasing concentration of PAM. However, high level of PAM (1mg/L) led to the formation of large amounts of loose-structure flocs, which eliminated dissolved oxygen transfer and caused the sludge disintegration, resulting in bad settleability and lower microbial activity. In this way, when the dosage of PAM was 0.1mg/L, the sludge had the best settling property and activity.
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Affiliation(s)
- Yuan-ling Luo
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China
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66
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Vieira RB, Vieira PA, Ribeiro EJ, Cardoso VL. The sedimentation of mixed cultures used in the treatment of effluents generated from terrestrial fuel distribution terminals. JOURNAL OF HAZARDOUS MATERIALS 2010; 184:177-183. [PMID: 20832164 DOI: 10.1016/j.jhazmat.2010.08.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2010] [Revised: 07/27/2010] [Accepted: 08/07/2010] [Indexed: 05/29/2023]
Abstract
This study evaluated the use of coagulants (ferric chloride and aluminium sulphate) and an anionic polyelectrolyte (polyacrylamide) in the settling of a mixed culture (C(1)), which was used for the biodegradation of hydrocarbons present in effluent of fuel distribution terminals contaminated with diesel oil and gasoline. In preliminary investigations conducted in jar tests, the optimal concentrations of coagulant were obtained for further studies. After preliminary tests, biodegradation was evaluated in a central composite design (CCD) with varying concentrations of ferric chloride and polyelectrolyte. Ferric chloride and polyelectrolyte concentrations ranged from 77.9 to 422.12 mg/L and 0.0 to 3.2mg/L, respectively. The responses monitored in CCD experiments included the sludge volume index (SVI), turbidity, and specific rate of oxygen uptake (SOUR), where values of 100mL/g, 840 nephelometric turbidity unit (NTU) and 58 mg O(2)/gh, respectively, were obtained. Subsequently, biodegradation was monitored in a sequencing batch reactor (SBR). The results indicated that within five cycles, total petroleum hydrocarbon (TPH) removal increased from 75 ± 1.0% to 79 ± 0.5%, while the volatile suspended solids (VSS) increased from 1300 to 2500 mg/L.
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Affiliation(s)
- R B Vieira
- Faculdade de Engenharia Química, Universidade Federal de Uberlândia, Campus Santa Mônica, 2121, CEP: 38400-902, Uberlândia, MG, Brazil.
| | - P A Vieira
- Faculdade de Engenharia Química, Universidade Federal de Uberlândia, Campus Santa Mônica, 2121, CEP: 38400-902, Uberlândia, MG, Brazil.
| | - E J Ribeiro
- Faculdade de Engenharia Química, Universidade Federal de Uberlândia, Campus Santa Mônica, 2121, CEP: 38400-902, Uberlândia, MG, Brazil.
| | - V L Cardoso
- Faculdade de Engenharia Química, Universidade Federal de Uberlândia, Campus Santa Mônica, 2121, CEP: 38400-902, Uberlândia, MG, Brazil.
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67
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Hasar H, Unsal SA, Ipek U, Karatas S, Cinar O, Yaman C, Kinaci C. Stripping/flocculation/membrane bioreactor/reverse osmosis treatment of municipal landfill leachate. JOURNAL OF HAZARDOUS MATERIALS 2009; 171:309-317. [PMID: 19559524 DOI: 10.1016/j.jhazmat.2009.06.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2008] [Revised: 05/29/2009] [Accepted: 06/02/2009] [Indexed: 05/28/2023]
Abstract
This study presents a configuration for the complete treatment of landfill leachate with high organic and ammonium concentrations. Ammonia stripping is performed to overcome the ammonia toxicity to aerobic microorganisms. By coagulation-flocculation process, COD and suspended solids (SS) were removed 36 and 46%, respectively. After pretreatment, an aerobic/anoxic membrane bioreactor (Aer/An MBR) accomplished the COD and total inorganic nitrogen (total-N(i)) removals above 90 and 92%, respectively, at SRT of 30 days. Concentrations of COD and total-N(i) (not considering organic nitrogen) in the Aer/An MBR effluent decreased to 450 and 40 mg/l, respectively, by significant organic oxidation and nitrification/denitrification processes. As an advanced treatment for the leachate, the reverse osmosis (RO) was applied to the collected Aer/An MBR effluents. Reverse osmosis provided high quality effluent by reducing the effluent COD from MBR to less than 4.0mg/l at SRT of 30 days.
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Affiliation(s)
- Halil Hasar
- Department of Environmental Engineering, Faculty of Engineering, Firat University, 23119 Elazig, Turkey.
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68
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Gannoun H, Bouallagui H, Okbi A, Sayadi S, Hamdi M. Mesophilic and thermophilic anaerobic digestion of biologically pretreated abattoir wastewaters in an upflow anaerobic filter. JOURNAL OF HAZARDOUS MATERIALS 2009; 170:263-271. [PMID: 19501962 DOI: 10.1016/j.jhazmat.2009.04.111] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2008] [Revised: 04/28/2009] [Accepted: 04/28/2009] [Indexed: 05/27/2023]
Abstract
The hydrolysis pretreatment of abattoir wastewaters (AW), rich in organic suspended solids (fats and protein) was studied in static and stirred batch reactors without aeration in the presence of natural microbial population acclimated in a storage tank of AW. Microbial analysis showed that the major populations which contribute to the pretreatment of AW belong to the genera Bacillus. Contrary to the static pretreatment, the stirred conditions favoured the hydrolysis and solubilization of 80% of suspended matter into soluble pollution. The pretreated AW, in continuous stirred tank reactor (CSTR) at a hydraulic retention time (HRT) of 2 days, was fed to an upflow anaerobic filter (UAF) at an HRT of 2 days. The performance of anaerobic digestion of biologically pretreated AW was examined under mesophilic (37 degrees C) and thermophilic (55 degrees C) conditions. The shifting from a mesophilic to a thermophilic environment in the UAF was carried out with a short start-up of thermophilic condition. The UAF ran at organic loading rates (OLRs) ranging from 0.9 to 6g COD/Ld in mesophilic conditions and at OLRs from 0.9 to 9 g COD/Ld in thermophilic conditions. COD removal efficiencies of 80-90% were achieved for OLRs up to 4.5 g COD/Ld in mesophilic conditions, while the highest OLRs i.e. 9 g COD/Ld led to efficiencies of 70-72% in thermophilic conditions. The biogas yield in thermophilic conditions was about 0.32-0.45 L biogas/g of COD removed for OLRs up to 4.5 g COD/Ld. For similar OLR, the UAF in mesophilic conditions showed lower percentage of methanization. Mesophilic anaerobic digestion has been shown to destroy pathogens partially, whereas the thermophilic process was more efficient in the removal of indicator microorganisms and pathogenic bacteria at different organic loading rates.
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Affiliation(s)
- H Gannoun
- Department of Biological and Chemical Engineering, Laboratory of Microbial Ecology and Technology, National Institute of Applied Sciences and Technology, 1080 Tunis, Tunisia
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69
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Characteristics of BPA removal from water by PACl-Al13 in coagulation process. J Colloid Interface Sci 2009; 337:408-13. [DOI: 10.1016/j.jcis.2009.05.052] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2009] [Revised: 05/19/2009] [Accepted: 05/21/2009] [Indexed: 11/20/2022]
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70
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Anirudhan TS, Rijith S, Divya L. Preparation and Application of a Novel Functionalized Coconut Coir Pith as a Recyclable Adsorbent for Phosphate Removal. SEP SCI TECHNOL 2009. [DOI: 10.1080/01496390903017899] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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71
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Gotvajn AZ, Tisler T, Zagorc-Koncan J. Comparison of different treatment strategies for industrial landfill leachate. JOURNAL OF HAZARDOUS MATERIALS 2009; 162:1446-1456. [PMID: 18650010 DOI: 10.1016/j.jhazmat.2008.06.037] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2007] [Revised: 06/11/2008] [Accepted: 06/12/2008] [Indexed: 05/26/2023]
Abstract
The aim of our research was to determine appropriate treatment technique for effective treatment of heavily polluted tannery landfill leachate. We have accomplished several treatment experiments: (i) aerobic biological treatment, (ii) air stripping at various pH, (iii) adsorption to activated carbon, (iv) coagulation-flocculation and (v) advanced oxidation process with Fe(2+)/H(2)O(2). Efficiency of each procedure was monitored by chemical analysis and changes in biodegradability and acute toxicity were also evaluated (Vibrio fischeri and Daphnia magna). Biological treatment of raw leachate was effective only for very diluted leachate (up to 6Vol.%). It has been confirmed that air stripping at pH 11.0 effectively removed volatile organics and ammonia for 33% and 84%, respectively and contributed to lower toxicity of the leachate. Fenton's oxidation was the most effective among all used treatment procedures. COD removal reached 86%, biodegradability has been increased and toxicity reduced. Adsorption to activated carbon increased BOD(5)/COD ratio from 0.18 to 0.56 and it removed 40% of organics. Coagulation and flocculation procedures with FeCl(3) were also very effective. At lowered pH and added flocculant treatment efficiency reached 50%. But no method alone was effective enough to meet effluent limits for release into local surface waters. Future work was focused on the study of different promising treatment schemes, especially combination of Fenton's oxidation and biological treatment.
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Affiliation(s)
- A Zgajnar Gotvajn
- University of Ljubljana, Faculty of Chemistry and Chemical Technology, Askerceva 5, SI-1000 Ljubljana, Slovenia.
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de Sena RF, Moreira RFPM, José HJ. Comparison of coagulants and coagulation aids for treatment of meat processing wastewater by column flotation. BIORESOURCE TECHNOLOGY 2008; 99:8221-8225. [PMID: 18442902 DOI: 10.1016/j.biortech.2008.03.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2006] [Revised: 03/07/2008] [Accepted: 03/10/2008] [Indexed: 05/26/2023]
Abstract
The physicochemical treatment of the wastewater from a meat processing industry was studied using three ferric salts as coagulants in conjunction with four different polymers as coagulation aids by batch column flotation. The effluent was characterized in terms of pH (6.5-6.7), turbidity (1000-12000 NTU), total solids (TS) (2300-7000mgl(-1)), oils and greases (OG) (820-1050mgl(-1)), and biochemical and chemical oxygen demands (BOD(5) and COD) (1200-1760 and 2800-3230mgl(-1)), respectively. The treatments achieved typical organic load reductions of oils and greases, and total solids (up to 85%), as well as biochemical and chemical oxygen demands (between 62.0-78.8% and 74.6-79.5%, respectively). The research also found that the utilization of a column flotation achieved high efficiency of organic matter removal and its operation as a primary treatment showed no significant dependence of pollutant removal and air flow rate.
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Affiliation(s)
- Rênnio F de Sena
- Laboratory of Energy and the Environment (LEMA), Department of Chemical Engineering and Food Engineering (EQA), Federal University of Santa Catarina (UFSC), Florianópolis, SC 88040-900, Brazil.
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74
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Lv L, Sun P, Wang Y, Du H, Gu T. Phosphate Removal and Recovery with Calcined Layered Double Hydroxides as an Adsorbent. PHOSPHORUS SULFUR 2008. [DOI: 10.1080/10426500701761730] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Liang Lv
- a College of Environmental Science and Engineering , Zhejiang Gongshang University , Zhejiang, China
- b West Branch of Zhejiang University of Technology , Zhejiang, China
| | - Peide Sun
- a College of Environmental Science and Engineering , Zhejiang Gongshang University , Zhejiang, China
| | - Yulin Wang
- b West Branch of Zhejiang University of Technology , Zhejiang, China
| | - Hangen Du
- a College of Environmental Science and Engineering , Zhejiang Gongshang University , Zhejiang, China
| | - Tingting Gu
- b West Branch of Zhejiang University of Technology , Zhejiang, China
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75
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Georgantas DA, Grigoropoulou HP. Orthophosphate and metaphosphate ion removal from aqueous solution using alum and aluminum hydroxide. J Colloid Interface Sci 2007; 315:70-9. [PMID: 17692328 DOI: 10.1016/j.jcis.2007.06.058] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2007] [Revised: 06/22/2007] [Accepted: 06/26/2007] [Indexed: 10/23/2022]
Abstract
The removal of orthophosphates (10(-2) kg P m(-3)), condensed phosphates (10(-2) kg P m(-3)), and mixtures of both (5 x 10(-3) kg P m(-3) as orthophosphate and 5 x 10(-3) kg P m(-3) as metaphosphate) in aqueous solution is studied using alum and aluminum hydroxide. The effects of coagulant dose, pH, temperature, aging of aluminum hydroxide, and presence of different ions are investigated. On the basis of the experimental results, alum is much more efficient in phosphorus removal than aluminum hydroxide even if, in both cases, at the conditions studied, the active coagulant form is Al(OH)(3). The differences then could be due to the higher activity of the in situ formed hydroxide. Orthophosphates and metaphosphates seem to have similar behavior vs pH variation: maximum removal is achieved at pH values 5-6 in all cases. On the other hand, in the simultaneous presence of both P forms, orthophosphate and metaphosphate ions have different affinities for the surface sites of aluminum hydroxide, since for both alum and aluminum hydroxide, orthophosphates are preferentially removed compared to metaphosphates, due probably to orientation effects and the charge per P atom. The presence of sodium, potassium, magnesium, sulfate, chloride, and magnesium, at the concentrations studied and for a pH value of 6, does not influence P removal. Temperature variation, between 25 and 60 degrees C, does not affect alum efficiency but both P forms are increasingly removed with increasing temperature, probably due to polymer Al(OH)(3) breaking, producing new surfaces for adsorption. Aging decreases sorption capacity of Al(OH)(3), while crystallites of increasing size are formed. Finally adsorption of both P forms is best described by the Freundlich isotherm [[K(F)=(49.1-69.1) x 10(-3) (m(3)kg(-1))(1/N), 1/N: 0.14-0.19 for T=25-60 degrees C] and [ K(F)=(1.58-2.79) x 10(-3) (m(3)kg(-1))(1/N), 1/N: 2.17-2.47 for T=25-60 degrees C] for orthophosphate and metaphosphate, respectively.
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Affiliation(s)
- D A Georgantas
- Laboratory of Chemical Process Engineering, School of Chemical Engineering, National Technical University of Athens, Zografou Campus, GR-15780 Zografos, Athens, Greece
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76
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Yilmaz AE, Boncukcuoğlu R, Kocakerim MM. A quantitative comparison between electrocoagulation and chemical coagulation for boron removal from boron-containing solution. JOURNAL OF HAZARDOUS MATERIALS 2007; 149:475-81. [PMID: 17524554 DOI: 10.1016/j.jhazmat.2007.04.018] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2007] [Revised: 04/02/2007] [Accepted: 04/05/2007] [Indexed: 05/15/2023]
Abstract
This paper provides a quantitative comparison of electrocoagulation and chemical coagulation approaches based on boron removal. Electrocoagulation process delivers the coagulant in situ as the sacrificial anode corrodes, due to a fixed current density, while the simultaneous evolution of hydrogen at the cathode allows for pollutant removal by flotation. By comparison, conventional chemical coagulation typically adds a salt of the coagulant, with settling providing the primary pollutant removal path. Chemical coagulation was carried out via jar tests using aluminum chloride. Comparison was done with the same amount of coagulant between electrocoagulation and chemical coagulation processes. Boron removal obtained was higher with electrocoagulation process. In addition, it was seen that chemical coagulation has any effect for boron removal from boron-containing solution. At optimum conditions (e.g. pH 8.0 and aluminum dose of 7.45 g/L), boron removal efficiencies for electrocoagulation and chemical coagulation were 94.0% and 24.0%, respectively.
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Affiliation(s)
- A Erdem Yilmaz
- Atatürk University, Faculty of Engineering, Department of Environmental Engineering, 25240 Erzurum, Turkey.
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77
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Ahmad AL, Wong SS, Teng TT, Zuhairi A. Optimization of coagulation-flocculation process for pulp and paper mill effluent by response surface methodological analysis. JOURNAL OF HAZARDOUS MATERIALS 2007; 145:162-8. [PMID: 17161910 DOI: 10.1016/j.jhazmat.2006.11.008] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2006] [Revised: 11/06/2006] [Accepted: 11/06/2006] [Indexed: 05/12/2023]
Abstract
Coagulation-flocculation is a proven technique for the treatment of high suspended solids wastewater. In this study, the central composite face-centered design (CCFD) and response surface methodology (RSM) have been applied to optimize two most important operating variables: coagulant dosage and pH, in the coagulation-flocculation process of pulp and paper mill wastewater treatment. The treated wastewater with high total suspended solids (TSS) removal, low SVI (sludge volume index) and high water recovery are the main objectives to be achieved through the coagulation-flocculation process. The effect of interactions between coagulant dosage and pH on the TSS removal and SVI are significant, whereas there is no interaction between coagulant dosage and water recovery. Quadratic models have been developed for the response variables, i.e. TSS removal, SVI and water recovery based on the high coefficient of determination (R(2)) value of >0.99 obtained from the analysis of variances (ANOVA). The optimum conditions for coagulant dosage and pH are 1045mgL(-1) and 6.75, respectively, where 99% of TSS removal, SVI of 37mLg(-1) and 82% of water recovery can be obtained.
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Affiliation(s)
- A L Ahmad
- School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang, Malaysia.
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78
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Zayas Pérez T, Geissler G, Hernandez F. Chemical oxygen demand reduction in coffee wastewater through chemical flocculation and advanced oxidation processes. J Environ Sci (China) 2007; 19:300-305. [PMID: 17918591 DOI: 10.1016/s1001-0742(07)60049-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The removal of the natural organic matter present in coffee processing wastewater through chemical coagulation-flocculation and advanced oxidation processes (AOP) had been studied. The effectiveness of the removal of natural organic matter using commercial flocculants and UV/H2O2, UV/O3 and UV/H2O2/O3 processes was determined under acidic conditions. For each of these processes, different operational conditions were explored to optimize the treatment efficiency of the coffee wastewater. Coffee wastewater is characterized by a high chemical oxygen demand (COD) and low total suspended solids. The outcomes of coffee wastewater treatment using coagulation-flocculation and photodegradation processes were assessed in terms of reduction of COD, color, and turbidity. It was found that a reduction in COD of 67% could be realized when the coffee wastewater was treated by chemical coagulation-flocculation with lime and coagulant T-1. When coffee wastewater was treated by coagulation-flocculation in combination with UV/H2O2, a COD reduction of 86% was achieved, although only after prolonged UV irradiation. Of the three advanced oxidation processes considered, UV/H2O2, UV/O3 and UV/H2O2/O3, we found that the treatment with UV/H2O2/O3 was the most effective, with an efficiency of color, turbidity and further COD removal of 87%, when applied to the flocculated coffee wastewater.
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Affiliation(s)
- Teresa Zayas Pérez
- Postgrade in Environmental Sciences, Center of Chemistry, Institute of Science, Meriterious University Autonomous of Puebla. P.O. Box 1613, C. P. 72000, Puebla, Mexico.
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Kuzawa K, Jung YJ, Kiso Y, Yamada T, Nagai M, Lee TG. Phosphate removal and recovery with a synthetic hydrotalcite as an adsorbent. CHEMOSPHERE 2006; 62:45-52. [PMID: 15951001 DOI: 10.1016/j.chemosphere.2005.04.015] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2004] [Revised: 03/26/2005] [Accepted: 04/06/2005] [Indexed: 05/02/2023]
Abstract
Phosphate removal is important to control eutrophication and an ion exchange process is one of several treatment processes for this purpose. Hydrotalcite compounds (HTALs) are useful as adsorbents for phosphate removal because of their ion exchange properties. In this study, the adsorption properties of a granular synthetic HTAL for phosphate and the method of regeneration of the granular HTAL were examined. The adsorption isotherm of the granular HTAL was approximated by a modified Langmuir type, and the maximum adsorption capacity was 47.3 mg P g(-1), which corresponded to the content of HTAL in the granular one. Phosphate adsorbed on the HTAL was effectively desorbed with alkaline NaCl solutions and the HTAL was regenerated with 25 w/v% MgCl(2) solution. The regenerated HTAL could be reused repeatedly for the phosphate removal. Phosphate in the exhausted desorption solution was recovered as a precipitate of calcium phosphate by addition of CaCl(2), and the residual exhausted desorption solution could be also reused after supplying NaOH. The results suggest the possibility of an effective system for phosphate removal and recovery, which includes the following processes: adsorption, desorption, recovery of phosphate, and regeneration of the HTAL and the desorption solution.
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Affiliation(s)
- Kazumichi Kuzawa
- Department of Ecological Engineering, Toyohashi University of Technology, Tempaku-cho, Toyohashi 441-8580, Japan
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Arslan EI, Aslan S, Ipek U, Altun S, Yazicioğlu S. Physico-chemical treatment of marble processing wastewater and the recycling of its sludge. WASTE MANAGEMENT & RESEARCH : THE JOURNAL OF THE INTERNATIONAL SOLID WASTES AND PUBLIC CLEANSING ASSOCIATION, ISWA 2005; 23:550-9. [PMID: 16379124 DOI: 10.1177/0734242x05059668] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
In the first part of this study, the treatability of marble processing wastewater by the coagulation-flocculation process was investigated. Optimum coagulant-flocculant doses for turbidity removal in wastewater from the cutting, faience and equalization processes were determined as 500, 200 and 500 ppm of Al2(SO4)3; 300, 500 and 300 ppm of FeCl3 and 600, 400 and 200 ppm of Agrofloc 100 (AGRON Water Treatment Technologies and Chemical Marketing Industry and Trade Limited Company, Izmir, Turkey), respectively. It was found that the removal of total solids from cutting and equalization process wastewaters was highest for the 100 ppm dosage of all chemicals used. The amount of total solids removed from faience process wastewater by Agrofloc 100 was higher than that removed by the other chemicals used. The removals of suspended solids from cutting, faience and equalization process wastewaters were similar to each other for each of the chemicals. The pH values after treatment by Agrofloc 100 were higher than the values determined after treatment by other chemicals for all process wastewater. Electrical conductivity values, however, were lower for Agrofloc 100 than for the others. Settled sludge volume experiments showed that settled sludge volumes decreased with time. The results of the quiescent settling experiment showed that the settling type could be termed flocculent settling. In the second part of the study, the usage of waste sludge from marble processing as an additive material in cement was investigated. The waste sludge originated from the wastewaters of different steps of the marble processing plant. Waste sludge was replaced with cement at various percentages by weight to prepare the mixtures of mortar. The specimens poured into the moulds were held for 24 h, removed from the moulds and held again for 28 days in lime-saturated water at 23 degrees C. Compressive and flexural strengths were evaluated with respect to percentages of waste sludge replaced with cement. The maximum compressive and flexural strengths were observed for specimens containing a 6% waste sludge when compared with control and it was also found that waste sludge up to 9% could effectively be used as an additive material in cement.
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Affiliation(s)
- E Işil Arslan
- Firat University, Engineering Faculty, Environmental Engineering Department, Elazig, Turkey.
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81
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Zhang K, Zhou Q. Toxic effects of Al-based coagulants on Brassica chinensis and Raphanus sativus growing in acid and neutral conditions. ENVIRONMENTAL TOXICOLOGY 2005; 20:179-187. [PMID: 15793823 DOI: 10.1002/tox.20093] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The ecotoxicological effects of aluminum (Al)-based coagulants are of concern because of their wide-ranging applications in wastewater treatment and water purification. As important Al-based coagulants, AlCl(3) and PAC (polyaluminum-chloride) were selected as examples to examine the toxic effects on representative vegetables including the cabbage Brassica chinensis and the radish Raphanus sativus over a range of exposure concentrations in neutral (pH 7.00) and acidic (pH 4.00) conditions, using seed germination and root elongation in the early-growth stage as indicators of toxicity. The results showed that root elongation of the two vegetables was a more sensitive indicator than was seed germination for evaluating the toxicity of Al. As a single influencing factor, H(+) had no significant direct effects on root elongation of Brassica chinensis and Raphanus sativus under the experimental conditions. The toxicity of Al played the main role in inhibiting root elongation and seed germination and was strongly related to changes in pH. There was a markedly positive relationship between the inhibitory rate of root elongation, seed germination, and the concentration of Al at pH 4.00 (p < 0.01). The toxic effect of AlCl(3) on Brassica chinensis was less with a neutral pH than at pH 4.00, but Raphanus sativus was more susceptible to AlCl(3) toxicity at a neutral pH than at pH 4.00. Both Raphanus sativus and Brassica chinensis had a more toxic response to a low concentration (<64 mg . L(-1)) of PAC in a neutral condition than in an acidic condition. Undoubtedly, the Al toxicity caused by Al-based coagulants at a neutral pH is relevant when treatment solids are used in agriculture.
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Affiliation(s)
- Kaisong Zhang
- Key Laboratory of Terrestrial Ecological Process, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, People's Republic of China
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82
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Kaetzke A, Jentzsch D, Eschrich K. Quantification of Microthrix parvicella in activated sludge bacterial communities by real-time PCR. Lett Appl Microbiol 2005; 40:207-11. [PMID: 15715646 DOI: 10.1111/j.1472-765x.2005.01656.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
AIMS This study was to develop a simple and reliable method for quantifying Microthrix parvicella 16S rRNA gene copies and its application to activated sludge samples collected from wastewater treatment plants (WWTP) with and without foaming problems. METHODS AND RESULTS The relative frequency of M. parvicella was determined by combining real-time PCR assays for quantification of total bacterial 16S rRNA gene copies and M. parvicella 16S rRNA gene copies. The developed method was applied to analyse 32 activated sludge samples obtained from German WWTP. The level of M. parvicella 16S rRNA gene copies in the 18 nonfoaming samples was below 3% of the total number of 16S rRNA gene copies and in the range of 0-18% for the 14 foaming samples. CONCLUSIONS The described method allows reliable monitoring of the amount of M. parvicella in activated sludge samples. SIGNIFICANCE AND IMPACT OF THE STUDY The described method may become an important component of a warning system for forthcoming bulking and foaming episodes.
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Affiliation(s)
- A Kaetzke
- Medical Faculty, Institute of Biochemistry, University of Leipzig, Leipzig, Germany
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83
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Levi? L, Gyura J, Djuri? M, Kuljanin T. Optimization of pH value and aluminium sulphate quantity in the chemical treatment of molasses. Eur Food Res Technol 2004. [DOI: 10.1007/s00217-004-1017-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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84
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Mittal GS. Characterization of the Effluent Wastewater from Abattoirs for Land Application. FOOD REVIEWS INTERNATIONAL 2004. [DOI: 10.1081/fri-200029422] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Tatsi AA, Zouboulis AI, Matis KA, Samaras P. Coagulation-flocculation pretreatment of sanitary landfill leachates. CHEMOSPHERE 2003; 53:737-744. [PMID: 13129513 DOI: 10.1016/s0045-6535(03)00513-7] [Citation(s) in RCA: 174] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Sanitary landfill leachates are considered as heavily polluted industrial wastewaters, presenting significant time and spatial variations of their physical-chemical parameters. Special care is required for their efficient treatment and disposal. The main aim of this work was to examine the application of coagulation-flocculation for the treatment of raw and partially stabilized leachates. Jar-test experiments were employed in order to determine the optimum conditions for the removal of organic matter and color, i.e. coagulant-flocculant combination, effective dosage and pH control. Ferric chloride, aluminium sulphate and lime were tested as conventional coagulants, whereas four commercial polyelectrolytes were co-examined: one anionic, two cationic and a non-ionic polymer. High chemical oxygen demand (COD) removal capacities (about 80%) were obtained during the addition of ferric chloride to the partially stabilized leachates, whereas low COD reductions (i.e. lower than 35%) were measured during the addition of coagulants in the raw samples. The addition of polyelectrolytes and pH adjustment in the alkaline region were found to affect slightly the removal of pollutants. The physico-chemical process may be used as a useful pretreatment step, especially for fresh leachates, prior to biological treatment, or as a post-treatment (polishing) step for partially stabilized leachates.
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Affiliation(s)
- A A Tatsi
- Department of Chemistry, Division of Chemical Technology, Aristotle University of Thessaloniki, Thessaloniki GR-541 24, Greece
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Yuan T, Luo QF, Hu JY, Ong SL, Ng WJ. A study on arsenic removal from household drinking water. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2003; 38:1731-1744. [PMID: 12940478 DOI: 10.1081/ese-120022875] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Arsenic removal from household drinking water has been receiving considerable attention in the field of water supply engineering. To develop the optimal coagulation protocol, the effectiveness of several operation options such as coagulants, coagulant aids and additives, as well as flocs separation systems were investigated in this study through the use of orthogonal array experiment based on Taguchi method. Arsenic removal mechanism during household coagulation (via manual mixing) was also discussed. The results showed that the addition of kaoline and powder activated carbon (PAC) did not enhance arsenic removal efficiency of ferric sulfate or aluminum sulfate. Similarly, mixture of ferric sulfate and aluminum sulfate (MFA) as well as polymeric ferric silicate sulfate (PFSiS) was also unable to improve the overall arsenic removal efficiency. The mechanism of arsenic removal during coagulation was somewhat different from those experienced in conventional processes. Coprecipitation appeared to be the crucial mechanism for arsenic removal. It is noted from this study that arsenic adsorption isotherm under household operation condition could be described by Langmuir equation. An efficient flocs separation system subsequent to coagulation was essential to achieve the effectiveness of overall arsenic removal. The results obtained from field experiment demonstrated that the method of ferric sulfate coagulation/sand filtration for arsenic removal from household drinking water was acceptable and affordable.
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Affiliation(s)
- Tao Yuan
- Centre for Water Research, Department of Civil Engineering, National University of Singapore, Singapore.
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