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Li N, Han Z, Ren Y, Wang S, Hu X, Zeng Z. Retarding performance of the vadose zone for nitrogen pollutants derived from municipal solid waste landfills in the red bed zone. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 306:114406. [PMID: 35016142 DOI: 10.1016/j.jenvman.2021.114406] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 11/29/2021] [Accepted: 12/27/2021] [Indexed: 06/14/2023]
Abstract
Nitrogen pollutants such as ammonia and nitrates cause soil and groundwater contamination at municipal solid waste landfill (MSWL) sites due to leachate leakage. Here, the migration of nitrogen pollutants in the vadose zone of the red bed (VZRB) at a MSWL site was studied by static adsorption batch experiments and one-dimensional simulated migration experiments. The results indicated that the soil in the red bed did not adsorb nitrates. Chemical adsorption and monolayer adsorption of the soil played dominant roles during ammonia adsorption in the VZRB, which was best fitted by the pseudo-second-order kinetic equation ( [Formula: see text] = 0.99) and the Langmuir model. The ammonia adsorption capacity of the soil was the highest (Qm = 2.041 mg·g-1) at 318 K. It was due to the endothermic and non-spontaneous chemical adsorption of ammonia, whose enthalpy change (ΔH) reached 20.995 kJ·mol-1 and Gibbs free energy ranged from 8.469 to 8.706 kJ·mol-1. Chloride penetration tests indicated that the diffusion coefficient and migration speed reached 0.0515 cm2·h-1 and 0.0833 cm·h-1, respectively, in the clay layer under the MSWL sites. The average hysteresis diffusion coefficients of ammonia in the simulated soil columns leached by ammonium chloride solution (SSCAC) and by the leachate from MSWL (SSCL) were 1.129 and 1.400, respectively. After the leaching experiments, the clay pore structure was saturated, and the specific surface area decreased. The absorption peak intensities of clay functional groups, including carboxyl, alkyne, and hydroxyl groups, were reduced. The ammonia content in the soil of SSCAC decreased from the top (14.51 mg·kg-1) to the bottom (3.14 mg·kg-1) and in the SSCL from 24.96 mg·kg-1 to 5.05 mg·kg-1, respectively. Thus, the impermeable clay layer and VZRB helped in retardation of ammonia leakage from MSWL sites. This was due to the blockage of seepage, ammonia mechanical filtration, ammonia monolayer chemical adsorption, and the reaction between the functional groups and ammonia in the VZRB underneath the MSWL sites.
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Affiliation(s)
- Naying Li
- State Key Laboratory of Geohazard Prevention and Geoenvironment Protection (Chengdu University of Technology), Chengdu, 610059, China; State Environmental Protection Key Laboratory of Synergetic Control and Joint Remediation for Soil & Water Pollution (Chengdu University of Technology), Chengdu, 610059, China; College of Ecology and Environment, Chengdu University of Technology, Chengdu, 610059, China
| | - Zhiyong Han
- State Key Laboratory of Geohazard Prevention and Geoenvironment Protection (Chengdu University of Technology), Chengdu, 610059, China; State Environmental Protection Key Laboratory of Synergetic Control and Joint Remediation for Soil & Water Pollution (Chengdu University of Technology), Chengdu, 610059, China; College of Ecology and Environment, Chengdu University of Technology, Chengdu, 610059, China.
| | - Yi Ren
- State Key Laboratory of Geohazard Prevention and Geoenvironment Protection (Chengdu University of Technology), Chengdu, 610059, China; State Environmental Protection Key Laboratory of Synergetic Control and Joint Remediation for Soil & Water Pollution (Chengdu University of Technology), Chengdu, 610059, China; College of Ecology and Environment, Chengdu University of Technology, Chengdu, 610059, China
| | - Shuangchao Wang
- State Key Laboratory of Geohazard Prevention and Geoenvironment Protection (Chengdu University of Technology), Chengdu, 610059, China; State Environmental Protection Key Laboratory of Synergetic Control and Joint Remediation for Soil & Water Pollution (Chengdu University of Technology), Chengdu, 610059, China; College of Ecology and Environment, Chengdu University of Technology, Chengdu, 610059, China
| | - Xinran Hu
- State Key Laboratory of Geohazard Prevention and Geoenvironment Protection (Chengdu University of Technology), Chengdu, 610059, China; State Environmental Protection Key Laboratory of Synergetic Control and Joint Remediation for Soil & Water Pollution (Chengdu University of Technology), Chengdu, 610059, China; College of Ecology and Environment, Chengdu University of Technology, Chengdu, 610059, China; Sichuan Jiashengyu Environmental Protection Technology Co. LTD
| | - Zhuojun Zeng
- State Key Laboratory of Geohazard Prevention and Geoenvironment Protection (Chengdu University of Technology), Chengdu, 610059, China; State Environmental Protection Key Laboratory of Synergetic Control and Joint Remediation for Soil & Water Pollution (Chengdu University of Technology), Chengdu, 610059, China; College of Ecology and Environment, Chengdu University of Technology, Chengdu, 610059, China
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Lü T, Ma W, Zhan D, Zou Y, Li J, Feng M, Huang X. Two New Three-Dimensional Lanthanide Metal-organic Frameworks for the Highly Efficient Removal of Cs + Ions ※. ACTA CHIMICA SINICA 2022. [DOI: 10.6023/a21120614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Kalaruban M, Loganathan P, Shim WG, Kandasamy J, Ngo HH, Vigneswaran S. Enhanced removal of nitrate from water using amine-grafted agricultural wastes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 565:503-510. [PMID: 27192699 DOI: 10.1016/j.scitotenv.2016.04.194] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 04/29/2016] [Accepted: 04/29/2016] [Indexed: 06/05/2023]
Abstract
Adsorption using low-cost adsorbents is a favourable water treatment method for the removal of water contaminants. In this study the enhanced removal of nitrate, a contaminant at elevated concentration affecting human health and causing eutrophication of water, was tested using chemically modified agricultural wastes as adsorbents. Batch and fixed-bed adsorption studies were performed on corn cob and coconut copra that were surface modified by amine-grafting to increase the surface positive charges. The Langmuir nitrate adsorption capacities (mgN/g) were 49.9 and 59.0 for the amine-grafted (AG) corn cob and coconut copra, respectively at pH6.5 and ionic strength 1×10(-3)M NaCl. These values are higher than those of many commercially available anion exchange resins. Fixed-bed (15-cm height) adsorption capacities (mgN/g) calculated from the breakthrough curves were 15.3 and 18.6 for AG corn cob and AG coconut copra, respectively, for an influent nitrate concentration 20mg N/L at a flow velocity 5m/h. Nitrate adsorption decreased in the presence of sulphate, phosphate and chloride, with sulphate being the most competitive anion. The Thomas model fitted well to the fixed-bed adsorption data from four repeated adsorption/desorption cycles. Plug-flow model fitted well to the data from only the first cycle.
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Affiliation(s)
- Mahatheva Kalaruban
- Faculty of Engineering, University of Technology Sydney (UTS), P.O. Box 123, Broadway, NSW 2007, Australia
| | - Paripurnanda Loganathan
- Faculty of Engineering, University of Technology Sydney (UTS), P.O. Box 123, Broadway, NSW 2007, Australia
| | - W G Shim
- Faculty of Engineering, University of Technology Sydney (UTS), P.O. Box 123, Broadway, NSW 2007, Australia; Department of Polymer Science and Engineering, Sunchon National University, 255 Jungang-ro, Suncheon, Jeollanam-do, Republic of Korea
| | - Jaya Kandasamy
- Faculty of Engineering, University of Technology Sydney (UTS), P.O. Box 123, Broadway, NSW 2007, Australia
| | - H H Ngo
- Faculty of Engineering, University of Technology Sydney (UTS), P.O. Box 123, Broadway, NSW 2007, Australia
| | - Saravanamuthu Vigneswaran
- Faculty of Engineering, University of Technology Sydney (UTS), P.O. Box 123, Broadway, NSW 2007, Australia.
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