Feasibility of sulfate-calcined eggshells for removing pathogenic bacteria and antibiotic resistance genes from landfill leachates.
High abundance of human pathogen and antibiotic resistance genes (ARGs) in landfill leachate has become an emerging threat against human health. Therefore, sulfate- and calcination-modified eggshells as green agricultural bioresource were applied to test the feasibility of removing pathogenic bacteria and ARGs from leachate. The highest removal of Escherichia coli (E. coil) and gentamycin resistant gene (gmrA) from artificial contaminated landfill leachate was achieved by the application of eggshell with combined treatment of sulfate and calcination. The 16S and gmrA gene copies of E. coil declined significantly from 1.78E8±8.7E6 and 4.12E8±5.9E6 copies mL-1to 1.32E7±2.6E6 and 2.69E7±7.2E6 copies mL-1, respectively, within 24h dynamic adsorption equilibrium process (p<0.05). Moreover, according to the Langmuir kinetic model, the greatest adsorption amount (1.56×109CFU E. coil per gram of modified eggshells) could be obtained at neutral pH of 7.5. The optimal adsorption eggshells were then screened to the further application in three typical landfill leachates in Nanjing, eastern China. Significant decrease in species and abundance of pathogenic bacteria and ARGs (tet, sul, erm, qnr, and ampC) indicated its great efficiency to purify landfill leachates. This study demonstrated that sulfate-calcined eggshells can be an environmentally-friendly and highly efficient bioadsorbent to the management of reducing dissemination risk of pathogen and ARGs in landfill leachate.
Key Laboratory of Soil Environmental and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, PR China; Department of Civil Engineering, University of Nebraska-Lincoln, 844 North 16th Street, Lincoln, NE 68588-6105, United States. Electronic address: yemao@issas.ac.cn.
Mao
M
Ye
Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China; Department of Soil and Crop Sciences, Texas A&M University, College Station, TX 88743, USA.
Mingming
M
Sun
Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China.
Xu
X
Chen
Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, PR China.
Yanfang
Y
Feng
Nanjing Institute of Environmental Science, Ministry of Environmental Protection of China, Nanjing 210042, PR China.
Jinzhong
J
Wan
Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China.
Kuan
K
Liu
Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China.
Da
D
Tian
Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China.
Manqiang
M
Liu
Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China.
Jun
J
Wu
Department of Soil and Crop Sciences, Texas A&M University, College Station, TX 88743, USA.
Arthur P
AP
Schwab
Key Laboratory of Soil Environmental and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, PR China. Electronic address: Jiangxin@issas.ac.cn.
Xin
X
Jiang
D000818:Animals; D001419:Bacteria; D002681:China; D004352:Drug Resistance, Microbial / Q000235:genetics*; D004528:Egg Shell; D005798:Genes, Bacterial; D014865:Waste Disposal, Fluid / Q000379:methods*; D014871:Water Microbiology; D014874:Water Pollutants, Chemical / Q000032:analysis
D014874:Water Pollutants, Chemical
ARGs; Adsorption; Eggshells; Landfill leachate; Pathogenic bacteria