1
|
Shu S, Li Y, Zhu W, Wu S, Wu Y, Hou H. Comparing desorption properties of pollutants on bentonite particles and in compacted bentonite. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 211:111940. [PMID: 33476849 DOI: 10.1016/j.ecoenv.2021.111940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 01/07/2021] [Accepted: 01/11/2021] [Indexed: 06/12/2023]
Abstract
Desorption is one of the main factors causing groundwater and soil pollution. Therefore, the study of clay desorption characteristics is important for the prediction of groundwater and soil pollution. In previous studies, batch tests and column tests were used to study the desorption characteristics of pollutants on clay. However, the desorption parameters obtained via the two test methods were often quite different. To investigate differences in the desorption characteristics of different pollutants on clay particles and in compacted clay, batch and column desorption tests were conducted using cadmium chloride, fulvic acid, and sodium phosphate as the adsorbates and bentonite as the adsorbent. It was found that the unit particle surface area desorption distribution coefficients of pollutants on bentonite particles were approximately equal to the unit pore surface area distribution coefficients of pollutants in compacted bentonite. This indicates that the desorbed amount per unit of surface area is basically consistent, regardless of whether they are sorbed on particles or in compacted bentonite. A simple formula for determining the desorption retardation factor of pollutants in compacted bentonite is presented. The results of this study provide a reference for the prediction and evaluation of groundwater and soil pollution.
Collapse
Affiliation(s)
- Shi Shu
- Key laboratory of Ministry of Education for Geomechanics and Embankment Engineering, Hohai University, Nanjing 210024, China.
| | - Yunquan Li
- Huadong Engineering Corporation Limited, Power China, Hangzhou 310000, China
| | - Wei Zhu
- Key laboratory of Ministry of Education for Geomechanics and Embankment Engineering, Hohai University, Nanjing 210024, China; College of Environment, Hohai University, Nanjing 210024, China
| | - Silin Wu
- Key laboratory of Ministry of Education for Geomechanics and Embankment Engineering, Hohai University, Nanjing 210024, China
| | - Yong Wu
- Key laboratory of Ministry of Education for Geomechanics and Embankment Engineering, Hohai University, Nanjing 210024, China
| | - Hao Hou
- Key laboratory of Ministry of Education for Geomechanics and Embankment Engineering, Hohai University, Nanjing 210024, China
| |
Collapse
|
2
|
Wang S, Wu J, Jiang J, Masum S, Xie H. Lead adsorption on loess under high ammonium environment. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:4488-4502. [PMID: 32940835 DOI: 10.1007/s11356-020-10777-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Accepted: 09/08/2020] [Indexed: 06/11/2023]
Abstract
Lead (Pb) is one of the most toxic, hazardous pollutants available in landfill leachate. Loess-amended soil buffers are found suitable and effective in attenuating migration of Pb and the other trace metals. High concentration of ammonium (NH4+ > 1000 mg/l) is also reported in landfill leachate, and therefore, it is essential to investigate the transport of lead under such condition. In this study, the mechanisms and the capacity of loess to adsorb Pb under high NH4+ concentration were investigated. Adsorption isotherm test data were obtained for 25 °C, 35 °C and 45 °C. The maximum adsorption capacity is estimated to be 2101.97 mg/g at 25 °C and 4292.8 mg/g at 45 °C under 1000 mg/l NH4+. The binding sites of Pb on loess are positively related to each other at low temperatures (25-35 °C). The thermodynamic analysis indicates that adsorption process is endothermic and non-spontaneous and the system randomness increases with reaction time. The kinetic test data, fitted with a pseudo-second-order kinetic model and an intraparticle diffusion model, suggests that removal of Pb is driven by both membrane and intraparticle diffusions. The SEM, XRD and FTIR analyses indicate flocculation, precipitations as well as some ion exchange processes, which perhaps combinedly increases adsorption of both NH4+ and Pb in loess. The two kinds of precipitations are involved for the removal of Pb. The precipitations of PbCO3, Pb(OH)2 and PbCO3·2H2O are formed by the reactions between calcite and lead. The other precipitation of white basic salt (Pb2O(NO3)2) is formed by the reactions among Pb2+, NO3- and aqueous ammonia under alkaline environment of loess slurry.
Collapse
Affiliation(s)
- Shaoyi Wang
- College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, 310058, China
| | - Jiawei Wu
- College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, 310058, China
| | - Jianqun Jiang
- College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, 310058, China
| | - Shakil Masum
- Geoenvironmental Research Centre, Cardiff University, S Glam, Cardiff, Wales, CF24 3AA, UK
| | - Haijian Xie
- College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, 310058, China.
| |
Collapse
|
3
|
Shu S, Zhu W, Xu H, Fan X, Wu S, Shi J, Song J. A new method for determination of heavy metal adsorption parameters in compacted clay by batch tests. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 181:114-120. [PMID: 31176245 DOI: 10.1016/j.ecoenv.2019.05.087] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 05/27/2019] [Accepted: 05/31/2019] [Indexed: 06/09/2023]
Abstract
Evaluation of adsorption properties of pollutants on artificial or natural clay strata is normally considered in investigations of soil and groundwater pollution. Batch adsorption tests can be used to obtain the adsorption parameters of clay particles; however, the results from these tests are usually very different from the adsorption of actual clay strata. If the adsorption parameters obtained by batch tests are used to directly evaluate the properties of adsorption of pollutants onto compacted clay, the predicted groundwater and soil pollution will be unsafe. Although the column diffusion tests are closer to the actual situation, they may require much more time, and diffusion and adsorption occur simultaneously in tests, making it difficult to accurately determine the adsorption parameters. To solve this problem, batch adsorption and column diffusion tests were conducted using three kinds of clay materials to investigate the mechanism of the differences in adsorption properties of heavy metal on clay particles and in compacted clay. The amount of adsorption per unit particle surface area of clay particles was found to be equal to that per unit pore surface area of compacted clay. A new simplified method was proposed to determine the adsorption parameters in compacted clay. It is easy to use and provide a reference for prediction and evaluation of soil and groundwater pollution.
Collapse
Affiliation(s)
- Shi Shu
- Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering, Hohai University, Nanjing, 210024, China; Jiangsu Research Center for Geotechnical Engineering Technology, Hohai University, Nanjing, 210024, China.
| | - Wei Zhu
- College of Environment, Hohai University, Nanjing, 210024, China
| | - Haoqing Xu
- School of Architecture and Civil Engineering, Jiangsu University of Science and Technology, 212003, Zhenjiang, China
| | - Xihui Fan
- Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering, Hohai University, Nanjing, 210024, China; Jiangsu Research Center for Geotechnical Engineering Technology, Hohai University, Nanjing, 210024, China
| | - Silin Wu
- Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering, Hohai University, Nanjing, 210024, China; Jiangsu Research Center for Geotechnical Engineering Technology, Hohai University, Nanjing, 210024, China
| | - Jianyong Shi
- Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering, Hohai University, Nanjing, 210024, China; Jiangsu Research Center for Geotechnical Engineering Technology, Hohai University, Nanjing, 210024, China
| | - Jie Song
- Hangzhou Ruhr Technology Co., Ltd., Hangzhou, 311100, China
| |
Collapse
|
4
|
Metwally SS, El-Sherief EA, Mekhamer HS. Fixed-bed column for the removal of cesium, strontium, and lead ions from aqueous solutions using brick kiln waste. SEP SCI TECHNOL 2019. [DOI: 10.1080/01496395.2019.1572189] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
5
|
Madbouly H, El-Hefny N, El-Nadi Y. Adsorption and separation of terbium(III) and gadolinium(III) from aqueous nitrate medium using solid extractant. SEP SCI TECHNOL 2019. [DOI: 10.1080/01496395.2018.1563614] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- H.A. Madbouly
- Hot Laboratories Centre, Atomic Energy Authority, Qalyubia, Egypt
| | - N.E. El-Hefny
- Hot Laboratories Centre, Atomic Energy Authority, Qalyubia, Egypt
| | - Y.A. El-Nadi
- Hot Laboratories Centre, Atomic Energy Authority, Qalyubia, Egypt
| |
Collapse
|
6
|
Bauer T, Pinskii D, Minkina T, Nevidomskaya D, Mandzhieva S, Burachevskaya M, Chaplygin V, Popileshko Y. Time effect on the stabilization of technogenic copper compounds in solid phases of Haplic Chernozem. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 626:1100-1107. [PMID: 29898517 DOI: 10.1016/j.scitotenv.2018.01.134] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 12/14/2017] [Accepted: 01/14/2018] [Indexed: 06/08/2023]
Abstract
We studied the regularities of Cu stabilization in Haplic Chernozem contaminated with easily soluble (acetates, nitrates, sulfates, chlorides) and poorly soluble (acetates, nitrates, sulfates, chlorides) metal compounds in a five-year model experiment were studied. A low contents of Cu loosely bound compounds (LBC) (no >5% of total content) unchanging over time were revealed in the uncontaminated soil, which is indicative of the stability of soil processes. The Cu LBC content decreased over time in the soils contaminated with easily soluble compounds and increased in the soils contaminated with poorly soluble compounds. In both cases, the contents of Cu LBCs after 5 years of incubation remained higher than in the original uncontaminated soil. The effect of the attendant anions on the Cu LBC content was more apparent under the Cu application of 2000 mg kg-1 than at 300 mg kg-1. An inverse process characterized by an increase in the concentration of Cu LBCs over time was observed in the soil contaminated with Cu orthophosphate and oxide. Soil contaminated with different Cu compounds results in soil acidification. According to the effect on the decrease in soil pH, the attendant anions form the following series: SO42- ≈ Cl- > NO3- > Ac- > PO42- > O2-, which correlates with the Cu LBC content. Thus, the stabilization of Cu compounds in the soil is affected by the attendant anions and the interaction time of the metal with the soil solid phases.
Collapse
Affiliation(s)
- Tatiana Bauer
- Southern Federal University, Rostov-on-Don 344006, Russia
| | - David Pinskii
- Institute of Physicochemical and Biological Problems of Soil Science, Russian Academy of Sciences, Pushchino, 142290, Russia
| | | | | | | | | | | | | |
Collapse
|
7
|
|