Use of combined coagulation-adsorption process as pretreatment of landfill leachate

Sludge-based activated carbons (SACs) prepared from sewage sludge and corn straw, were modified by ferric nitrate, and the unmodified SAC and modified SAC were used as the adsorbing agent to treat the landfill leachate, the elimination capacity for chemical oxygen demand (COD) and organic matter in leachate were studied. Based on this, the physicochemical properties of SACs and the components changes in leachate were analyzed and characterized by X-ray photoelectron spectroscopy and three-dimensional fluorescence spectroscopy. The results showed that under optimal experimental conditions, the elimination capacities of SAC372 for COD, biological oxygen demand over 5 days, and NH4+–N in the leachate were 81.58%, 54.73%, and 69.08%, respectively; while the adsorption capacities of modified SAC for these three substances were 86.25%, 63.51%, and 79.15%, respectively. The ferric nitrate modification improved the ability of SAC to eliminate COD and organic matter from leachate slightly, and made the adsorption occurred easily. The adsorption process of unmodified SAC was dominated by multi-layer adsorption, while the adsorption process of modified SAC was dominated by monolayer adsorption. The mass fraction of Fe (2p) in modified SAC remarkably increased, from 0.70% to 26.01%, organic functional groups certain phase of Fe oxides with different valence states were generated in SAC, which provided a substrate for iron–carbon micro electrolysis. After adsorbed by unmodified SAC and modified SAC adsorption, the total fluorescence intensity of in the leachate increased by 17.01% and 116.84%, respectively. Both two SACs could decompose the humic acid-like substances into aromatic protein organic compounds, and modified SAC could further decompose the soluble microbial byproduct-like substances.

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Advanced treatment of landfill leachate membrane concentrates: performance comparison, biosafety and toxic residue analysis

Water Science & Technology ◽

10.2166/wst.2017.469 ◽

2017 ◽

Vol 76 (11) ◽

pp. 2949-2958 ◽

Cited By ~ 4

Author(s):

Mianwei Hong ◽

Gang Lu ◽

Changcheng Hou ◽

Shaohua She ◽

Lingfei Zhu

Keyword(s):

Activated Carbon ◽

Acute Toxicity ◽

Landfill Leachate ◽

Adsorption Process ◽

Residue Analysis ◽

Performance Comparison ◽

Gas Chromatography Mass Spectrometry ◽

Activated Carbon Adsorption ◽

Carbon Adsorption ◽

Membrane Concentrates

Abstract With the improvement of people's consciousness about health, more attention has been paid to the biosafety of effluent reaching conventional discharge standard. In this contribution, removal efficiency of chemical oxygen demand (COD), acute toxicity, genotoxicity and estrogenicity in landfill leachate membrane concentrates (MCs) among UV-Fenton, Fenton and activated carbon adsorption process were compared. Daphnia magna acute toxicity assay, comet assay, cytokinesis-block micronucleus and E-screen assay were performed to assess whether the effluent reaching the main parameters of Chinese Discharge Standard (GB 16889-2008) still had toxic residues. Under the conditions that COD of effluents treated by the three processes were up to the discharge standard, no obvious toxic residue was found in the effluent of UV-Fenton treatment, but effluent from Fenton or activated carbon adsorption process showed genotoxicity or estrogenicity to some extent. Dynamic analysis of UV-Fenton degradation process for estrogen simulation solutions was also conducted, and the formation of intermediates was detected by gas chromatography–mass spectrometry (GC/MS). Toxic residues might be caused by the lack of treatment duration and the formation of more toxic intermediates. UV-Fenton was found to be efficient for the treatment of MCs. Biosafety should be concerned when a new wastewater discharge standard is being established.

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Treatment of a landfill leachate from Casablanca city by a coagulation-flocculation and adsorption process using a palm bark powder (PBP)

Scientific African ◽

10.1016/j.sciaf.2021.e00721 ◽

2021 ◽

pp. e00721

Author(s):

Z. Chaouki ◽

M. Hadri ◽

M. Nawdali ◽

M. Benzina ◽

H. Zaitan

Keyword(s):

Landfill Leachate ◽

Adsorption Process

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

Chemical Engineering Communications ◽

10.1080/00986445.2021.2018308 ◽

2021 ◽

pp. 1-13

Author(s):

Roger I. Méndez-Novelo ◽

Liliana San-Pedro ◽

Armin A. May-Marrufo ◽

Emanuel Hernandez-Núñez ◽

Caridad Vales-Pinzón ◽

...

Keyword(s):

Landfill Leachate ◽

Adsorption Process ◽

Sanitary Landfill ◽

Sanitary Landfill Leachate

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Landfill leachate treatment using activated carbon obtained from coffee waste

Engenharia Sanitaria e Ambiental ◽

10.1590/s1413-41522019178655 ◽

2019 ◽

Vol 24 (4) ◽

pp. 833-842 ◽

Cited By ~ 1

Author(s):

Rodrigo Poblete Chávez ◽

Ernesto Cortes Cortés Pizarro ◽

Yolanda Luna Galiano

Keyword(s):

Activated Carbon ◽

Landfill Leachate ◽

Pore Diameter ◽

Adsorption Process ◽

Oxygen Demand ◽

Leachate Treatment ◽

K Value ◽

Coffee Waste ◽

Pore Area ◽

Median Pore

ABSTRACT A set of experiments were carried out in order to establish and evaluate the potential of activated carbon, produced from coffee waste in adsorption process, in the depuration of landfill leachate. Different reagents were studied in the activation of carbon: HCl, HCl + H2O2, H3PO4, H3PO4 + H2O2, all with an impregnation rate of 1:1. The activated carbon that showed the best global results was activated with H3PO4, obtaining a 51.0, 32.8, 66.0, 81.0 and 97.1% elimination of chemical oxygen demand, ammonia, total chlorine, bromine and copper, respectively. This activated carbon has a total pore area of 4.85 m2/g and a median pore diameter of 65.32 micrometers. When different loads of this carbon were placed in a stirrer system in contact with landfill leachate, with the aim of evaluating the effect of the adsorption load and contact time, the concentration of ammonia decreased from the beginning of the adsorption process to the end of it, and the removal of ammonia increased with the increase in the adsorbent load. However, the trend of the amount adsorbed per unit mass decreased with increased dosage. The model Freundlich equilibrium isotherm fits experimental data adequately, giving R2 values of 0.95, 1/n of 0.5183, and a K value of 7.08*10-5 L/g, being favourable for adsorption process.

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