Post-treatment of sanitary landfill leachate by coagulation–flocculation using chitosan as primary coagulant

Chitosan was chosen as an alternative primary coagulant in a complementary coagulation–flocculation treatment of sanitary landfill leachate with the aim of removing recalcitrant organic matter. In order to optimize the process conditions, central composite design and response surface methodology were applied. To evaluate the performance of the process using chitosan, we also carried out tests with aluminium sulphate (Al2 (SO4)3.14 H2O) as coagulant. In addition, acute toxicity tests were carried using the duckweed Lemna minor and the guppy fish Poecilia reticulata as test organisms. The analytic hierarchy process was employed for selecting the most appropriate coagulant. Mean values of true colour removal efficiency of 80% and turbidity removal efficiency of 91.4% were reached at chitosan dosages of 960 mg L−1 at pH 8.5. The acute toxicity tests showed that organisms were sensitive to all samples, mainly after coagulation–flocculation using chitosan. CE50 for L. minor was not determined because there was no inhibition of the average growth rate and biomass production; LC50 for P. reticulata was 23% (v v−1). Multi-criteria analysis showed that alum was the most appropriate coagulant. Therefore, chitosan as primary coagulant was not considered to be a viable alternative in the post-treatment of landfill leachate.

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Landfill Leachate Toxicity Removal in Combined Treatment with Municipal Wastewater

The Scientific World JOURNAL ◽

10.1100/2012/202897 ◽

2012 ◽

Vol 2012 ◽

pp. 1-7 ◽

Cited By ~ 21

Author(s):

J. Kalka

Keyword(s):

Acute Toxicity ◽

Landfill Leachate ◽

Biological Treatment ◽

Municipal Wastewater ◽

Vibrio Fischeri ◽

Combined Treatment ◽

Treated Wastewater ◽

Toxicity Tests ◽

Raphidocelis Subcapitata ◽

Acute Toxicity Tests

Combined treatment of landfill leachate and municipal wastewater was performed in order to investigate the changes of leachate toxicity during biological treatment. Three laboratory A2O lab-scale reactors were operating under the same parameters (Q-8.5–10 L/d; HRT-1.4–1.6 d; MLSS 1.6–2.5 g/L) except for the influent characteristic and load. The influent of reactor I consisted of municipal wastewater amended with leachate from postclosure landfill; influent of reactor II consisted of leachate collected from transient landfill and municipal wastewater; reactor III served as a control and its influent consisted of municipal wastewater only. Toxicity of raw and treated wastewater was determinted by four acute toxicity tests withDaphnia magna, Thamnocephalus platyurus, Vibrio fischeri,andRaphidocelis subcapitata. Landfill leachate increased initial toxicity of wastewater. During biological treatment, significant decline of acute toxicity was observed, but still mixture of leachate and wastewater was harmful to all tested organisms.

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Reduction of acute toxicity of landfill leachate in co-treatement with domestic sewage by integrated fixed-film activated sludge reactor

Ambiente e Agua - An Interdisciplinary Journal of Applied Science ◽

10.4136/ambi-agua.1835 ◽

2016 ◽

Vol 11 (2) ◽

pp. 316

Author(s):

Fábio Campos ◽

Roque Passos Piveli

Keyword(s):

Acute Toxicity ◽

Activated Sludge ◽

Landfill Leachate ◽

Domestic Sewage ◽

Toxicity Tests ◽

Total Load ◽

Daphnia Similis ◽

Fixed Film ◽

Activated Sludge Reactor ◽

Acute Toxicity Tests

This study used acute toxicity tests on the marine bacteria Allivibrio fischeri and on microcrustaceans Daphnia similis to evaluate the reduction of acute toxicity in effluent generated by the IFAS (Integrated Fixed Film Activated Sludge) hybrid process, treating landfill leachate with domestic sewage. In order to evaluate the treatment’s ability to lessen the toxicity of the effluent, three experimental stages were developed with leachate contributions of 5, 10 and 20% of the total load of BOD in the effluent composition. In general, the results show that, even with the greatest contribution of leachate, no significant alterations were observed in the behavior and efficiency of the biological process; however, with regard to the degree of acute toxicity observed in the affluent, the classification of the effluents changed from Very Toxic to Toxic in three phases of operation, even reaching the reduction levels around 70% in the last stage of the study, highlighting the need for greater control and evaluation of this variable. The methodology of using the Microtox® technique proved to be more sensitive to compounds present in the samples when compared to the technique using the microcrustaceans D. similis.

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Acute Toxicity Testing with Juvenile White Sturgeon (Acipenser transmontanus)

Water Quality Research Journal ◽

10.2166/wqrj.1998.006 ◽

1998 ◽

Vol 33 (1) ◽

pp. 95-110 ◽

Cited By ~ 8

Author(s):

W.R. Bennett ◽

A.P. Farrell

Keyword(s):

Acute Toxicity ◽

Swimming Performance ◽

Juvenile Fish ◽

Toxicity Testing ◽

White Sturgeon ◽

Acipenser Transmontanus ◽

Toxicity Tests ◽

Fraser River ◽

Acute Toxicity Tests ◽

Acute Toxicity Testing

Abstract The primary goal of this study was to investigate the possibility of using early life stages of white sturgeon (Acipenser transmontanus) (eggs, larvae and fry) as a species relevant to the Fraser River, B.C., for the acute and sublethal toxico-logical testing of forest industry effluents. Here we report the first successful acute toxicity tests for 8-day-old larvae and 42-day-old fry exposed to several chemicals known to be released into the Fraser River (i.e., 6 monochlorovanillin [6 MVAN], 4,5 dichloroguaiacol [4,5 DCG], 4,5 dichlorocatechol [4,5 DCAT], pentachlorophenol [PCP], and didecyldimethylammonium chloride [DDAC]). In most cases, white sturgeon fry were at the lower end of the range for acute toxicity values for chlorinated phenolic compounds, when compared with other juvenile fish species, and they were extremely sensitive to DDAC. The larval stage was usually more sensitive than the fry stage. Acute toxicity tests with fertilized eggs were unsuccessful. A postexposure growth study was inconclusive because neither control nor toxicant-exposed larvae and fry withstood the additional handling used for measuring body mass. At 62-days-old, fry were more tolerant of handling. This allowed measurement of their swimming performance. Although we have concerns about the reliability of using larvae for acute toxicity testing at this time, 60-day-old white sturgeon fry would appear to be both a sensitive and relevant species for assessing environmental impacts relevant to the Fraser River.

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Application of Electrocoagulation with a New Steel-Swarf-Based Electrode for the Removal of Heavy Metals and Total Coliforms from Sanitary Landfill Leachate

Applied Sciences ◽

10.3390/app11115009 ◽

2021 ◽

Vol 11 (11) ◽

pp. 5009

Author(s):

Mayk Teles de Oliveira ◽

Ieda Maria Sapateiro Torres ◽

Humberto Ruggeri ◽

Paulo Scalize ◽

Antonio Albuquerque ◽

...

Keyword(s):

Heavy Metals ◽

Landfill Leachate ◽

Lower Cost ◽

Sanitary Landfill ◽

Leachate Treatment ◽

Removal Of Heavy Metals ◽

Waste Characteristics ◽

Electrode Passivation ◽

Steel Swarf ◽

Sanitary Landfill Leachate

Sanitary landfill leachate (LL) composition varies according to climate variables variation, solid waste characteristics and composition, and landfill age. Leachate treatment is essentially carried out trough biological and physicochemical processes, which have showed variability in efficiency and appear a costly solution for the management authorities. Electrocoagulation (EC) seems a suitable solution for leachate treatment taking into account the characteristics of the liquor. One of the problems of EC is the electrode passivation, which affects the longevity of the process. One solution to this problem could be the replacement of the electrode by one made of recyclable material, which would make it possible to change it frequently and at a lower cost. The objective of the present work was to evaluate the removal of heavy metals (As, Ba, Cd, Cr, Cu, Fe, Pb, Mn, Ni, Se and Zn) and coliforms from a LL by EC using electrodes made from steel swarf (SfE) up to 8 h. Removal efficiencies of detected heavy metals were 51%(Cr), 59%(As), 71%(Cd), 72%(Zn), 92%(Ba), 95%(Ni) and >99%(Pb). The microbial load of coliforms in leachate was reduced from 10.76 × 104 CFU/mL (raw leachate) to less than 1 CFU/mL (after treatment with SfE) (i.e., approximately 100% reduction). The use of SfE in EC of LL is very effective in removing heavy metals and coliforms and can be used as alternative treatment solution for such effluents.

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Book Review: Acute Toxicity Tests: Possible Alternatives

Alternatives to Laboratory Animals ◽

10.1177/026119298301100220 ◽

1983 ◽

Vol 11 (2) ◽

pp. 99-100

Author(s):

Michael Balls

Keyword(s):

Acute Toxicity ◽

Toxicity Tests ◽

Acute Toxicity Tests

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Resistance of bacteria isolated from leachate to heavy metals and the removal of Hg by Pseudomonas aeruginosa strain FZ-2 at different salinity levels in a batch biosorption system

Sustainable Environment Research ◽

10.1186/s42834-021-00088-6 ◽

2021 ◽

Vol 31 (1) ◽

Author(s):

Muhammad Fauzul Imron ◽

Setyo Budi Kurniawan ◽

Siti Rozaimah Sheikh Abdullah

Keyword(s):

Heavy Metals ◽

Heavy Metal ◽

Pseudomonas Aeruginosa ◽

Fresh Water ◽

Landfill Leachate ◽

Saline Water ◽

Resistant Bacteria ◽

Sanitary Landfill ◽

Salinity Levels ◽

Sanitary Landfill Leachate

AbstractLeachate is produced from sanitary landfills containing various pollutants, including heavy metals. This study aimed to determine the resistance of bacteria isolated from non-active sanitary landfill leachate to various heavy metals and the effect of salinity levels on the removal of Hg by the isolated bacterium. Four dominant bacteria from approximately 33 × 1017 colony-forming units per mL identified as Vibrio damsela, Pseudomonas aeruginosa, Pseudomonas stutzeri, and Pseudomonas fluorescens were isolated from non-active sanitary landfill leachate. Heavy metal resistance test was conducted for Hg, Cd, Pb, Mg, Zn, Fe, Mn, and Cu (0–20 mg L− 1). The removal of the most toxic heavy metals by the most resistant bacteria was also determined at different salinity levels, i.e., fresh water (0‰), marginal water (10‰), brackish water (20‰), and saline water (30‰). Results showed that the growth of these bacteria is promoted by Fe, Mn, and Cu, but inhibited by Hg, Cd, Pb, Mg, and Zn. The minimum inhibitory concentration (MIC) of all the bacteria in Fe, Mn, and Cu was > 20 mg L− 1. The MIC of V. damsela was 5 mg L− 1 for Hg and > 20 mg L− 1 for Cd, Pb, Mg, and Zn. For P. aeruginosa, MIC was > 20 mg L− 1 for Cd, Pb, Mg, and Zn and 10 mg L− 1 for Hg. Meanwhile, the MIC of P. stutzeri was > 20 mg L− 1 for Pb, Mg, and Zn and 5 mg L− 1 for Hg and Cd. The MIC of P. fluorescens for Hg, Pb, Mg, and Zn was 5, 5, 15, and 20 mg L− 1, respectively, and that for Cd was > 20 mg L− 1. From the MIC results, Hg is the most toxic heavy metal. In marginal water (10‰), P. aeruginosa FZ-2 removed up to 99.7% Hg compared with that in fresh water (0‰), where it removed only 54% for 72 h. Hence, P. aeruginosa FZ-2 is the most resistant to heavy metals, and saline condition exerts a positive effect on bacteria in removing Hg.

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