Optimization of the adsorption process in the treatment of sanitary landfill leachate by Fenton-adsorption

Author(s):  
Roger I. Méndez-Novelo ◽  
Liliana San-Pedro ◽  
Armin A. May-Marrufo ◽  
Emanuel Hernandez-Núñez ◽  
Caridad Vales-Pinzón ◽  
...  
2021 ◽  
Vol 11 (11) ◽  
pp. 5009
Author(s):  
Mayk Teles de Oliveira ◽  
Ieda Maria Sapateiro Torres ◽  
Humberto Ruggeri ◽  
Paulo Scalize ◽  
Antonio Albuquerque ◽  
...  

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.


2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Muhammad Fauzul Imron ◽  
Setyo Budi Kurniawan ◽  
Siti Rozaimah Sheikh Abdullah

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.


2016 ◽  
Vol 283 ◽  
pp. 76-88 ◽  
Author(s):  
Tânia F.C.V. Silva ◽  
Amélia Fonseca ◽  
Isabel Saraiva ◽  
Rui A.R. Boaventura ◽  
Vítor J.P. Vilar

2016 ◽  
Vol 74 (1) ◽  
pp. 246-255 ◽  
Author(s):  
Inara Oliveira do Carmo Nascimento ◽  
Ana Rosa Pinto Guedes ◽  
Louisa Wessels Perelo ◽  
Luciano Matos Queiroz

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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