A new insight into highly contaminated landfill leachate treatment using Kefir grains pre-treatment combined with Ag-doped TiO2 photocatalytic process

Lobna Elleuch; Mouna Messaoud; Kais Djebali; Marwa Attafi; Yasmin Cherni; Mariam Kasmi; Anis Elaoud; Ismail Trabelsi; Abdelwaheb Chatti

doi:10.1016/j.jhazmat.2019.121119

A new insight into highly contaminated landfill leachate treatment using Kefir grains pre-treatment combined with Ag-doped TiO₂ photocatalytic process

J Hazard Mater. 2020 Jan 15:382:121119. doi: 10.1016/j.jhazmat.2019.121119. Epub 2019 Aug 29.

Authors

Lobna Elleuch¹, Mouna Messaoud², Kais Djebali³, Marwa Attafi⁴, Yasmin Cherni⁴, Mariam Kasmi⁴, Anis Elaoud⁵, Ismail Trabelsi⁴, Abdelwaheb Chatti⁴

Affiliations

¹ Laboratory of Treatment and Valorization of Water Rejects, Water Researches and Technologies Center, Borj-Cedria Technopark, University of Carthage, 8020, Soliman, Tunisia. Electronic address: Lobna.Elleuch@certe.rnrt.tn.
² Laboratory of advanced Materials, National School of Engineers of Sfax, University of Sfax, 3038, Sfax, Tunisia.
³ Support Research and Technology Transfer Unit, Biotechnology Center Borj-Cedria Technopark, 2050, Hammam-Lif, Tunisia.
⁴ Laboratory of Treatment and Valorization of Water Rejects, Water Researches and Technologies Center, Borj-Cedria Technopark, University of Carthage, 8020, Soliman, Tunisia.
⁵ Laboratory of Environmental Science and Technologies, Higher Institute of Sciences and Technology of Environment, University of Carthage, 2050, Borj-Cedria, Tunisia.

PMID: 31494532
DOI: 10.1016/j.jhazmat.2019.121119

Abstract

This study investigates the performance of the combination of biological pre-treatment with Kefir grains (KGs) and photocatalytic process using Ag-doped TiO₂ nanoparticles (NPs) for the simultaneous removal of toxic pollutants from landfill leachate (LFL). After 5 days of 1% (w/v) KGs pre-treatment at 37 °C, TOC, COD, NH₄⁺-N, and PO₄^3- removal rates were 93, 83.33, 70 and 88.25%, respectively. The removal efficiencies were found to be 100, 94, 62.5, 53.16 and 47.52 % for Cd, Ni, Zn, Mn and Cu, respectively. The optimal conditions of Ag-doped TiO₂ photocatalytic process were optimized using Box-Behnken design and response surface methodology (BBD-RSM) to enhance the quality of pre-treated LFL. Interestingly, Ag-doped TiO₂ photocatalytic process increases the overall removal efficiencies to 98, 96, 85 and 93% of TOC, COD, NH₄⁺-N, and PO₄^3-, respectively. Furthermore, the removal efficiency of toxic heavy metals was gradually improved. In addition, KGs and Ag-doped TiO₂ exhibited excellent recyclability showing the potential of combined biological/photocatalytic process to treat hazardous LFL.

Keywords: Ag-doped TiO(2) nanoparticles; Box-behnken design; Combined process; Kefir grains pre-treatment; Landfill leachate; Recyclability.

MeSH terms

Ammonium Compounds / chemistry*
Ammonium Compounds / metabolism
Biodegradation, Environmental
Biological Oxygen Demand Analysis
Catalysis
Kefir / microbiology*
Light
Metals, Heavy / chemistry*
Metals, Heavy / metabolism
Nanoparticles / chemistry*
Nanoparticles / radiation effects
Phosphates / chemistry*
Phosphates / metabolism
Photochemical Processes
Titanium / chemistry*
Titanium / radiation effects
Tunisia
Waste Disposal Facilities
Water Pollutants, Chemical / chemistry*
Water Pollutants, Chemical / metabolism

Substances

Ammonium Compounds
Metals, Heavy
Phosphates
Water Pollutants, Chemical
titanium dioxide
Titanium