1
|
Jiang Y, Chen D, Yang P, Ning W, Cao M, Luo J. Influences of elevated O 3 and CO 2 on Cd distribution in different Festuca arundinacea tissues. CHEMOSPHERE 2022; 290:133343. [PMID: 34922963 DOI: 10.1016/j.chemosphere.2021.133343] [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: 11/22/2021] [Revised: 12/06/2021] [Accepted: 12/15/2021] [Indexed: 06/14/2023]
Abstract
It is necessary to reveal the responses of the biomass production and metal accumulation capacity of different plants to the variations of atmospheric conditions and soil metals, with the acceleration of urbanization and industrialization. In the present study, a series of experiments were designed to study the individual and interactive influences of O3 and CO2 fumigation on the biomass yield, variation in different leaf types, distribution of cadmium (Cd) in various tissues, and phytoremediation efficiency of Festuca arundinacea using open top chambers. The results found that an elevated O3 content of 80 ppb, a potential O3 content predicted for 2050, decreased the total dry mass of F. arundinacea and increased the proportion of falling leaf tissues of the species significantly. Under the same ambient CO2 levels, O3 fumigation increased the Cd concentrations in the roots and the fresh, mature, senescent, and dead leaf tissues by 27.8%, 133.3%, 94.4%, 125.3%, and 48.6%, respectively. An elevated CO2 content (550 ppm) promoted the biomass yield of F. arundinacea, particularly in the falling leaf tissues. The results of the combined O3 and CO2 treatment showed that CO2 fumigation alleviated the negative effects of O3 on plant growth and increased the accumulation capacity in different plant tissues. Significantly more Cd was accumulated in senescent and dead leaves under the synergistic action of CO2 and O3, suggesting that the phytoremediation effect on F. arundinacea using the falling leaves harvesting method could be improved under the future atmospheric environment of high CO2 and O3 levels.
Collapse
Affiliation(s)
- Yang Jiang
- College of Resources and Environment, Yangtze University, Wuhan, China
| | - Dan Chen
- College of Resources and Environment, Yangtze University, Wuhan, China
| | - Pan Yang
- College of Resources and Environment, Yangtze University, Wuhan, China
| | - Wenjing Ning
- College of Resources and Environment, Yangtze University, Wuhan, China
| | - Min Cao
- University of Leicester, University Road, Leicester, LE1 7RH, United Kingdom
| | - Jie Luo
- College of Resources and Environment, Yangtze University, Wuhan, China.
| |
Collapse
|
2
|
Xu L, Dai H, Skuza L, Wei S. The effects of different electrode materials on seed germination of Solanum nigrum L. and its Cd accumulation in soil. J Environ Sci (China) 2022; 113:291-299. [PMID: 34963538 DOI: 10.1016/j.jes.2021.06.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 06/16/2021] [Accepted: 06/18/2021] [Indexed: 06/14/2023]
Abstract
The effects of different electrode on Solanum nigrum L. seed germination were determined. The result showed that germination percentage (GP) of seeds in treatment T2 (titanium electrode) was 26.6% higher than in control (CK, without electric field). High potassium and calcium concentrations were beneficial for seed enzymatic activity in treatment T2, which could partly explain the increase in GP. Cd accumulation (μg/pot) in S. nigrum treated with any electric field was significantly higher (p<0.05) than in CK without electric field. Specifically, Cd accumulation under the treatment T3 (stainless steel electrode) was the highest both in roots and shoots; this accumulation in shoots and roots were 74.7 % and 67.4 % higher for stainless steel than in CK. This increase must have been associated with a higher Cd concentration in plants and did not exert a significant effect on the biomass. In particular, Cd concentrations in roots and shoots under stainless steel treatment were both significantly higher than in CK (p<0.05), which had to be related to the higher available Cd concentration in the soil in the middle region. Furthermore, it could be attributed to altered soil pH and other soil properties. Moreover, none of the biomasses were significantly affected (p<0.05) by different electrode materials compared to CK.
Collapse
Affiliation(s)
- Lei Xu
- Key Laboratory of Pollution Ecology and Environment Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China; University of Chinese Academy of Sciences, Beijing 100039, China
| | - Huiping Dai
- College of Biological Science & Engineering, Shaanxi Province Key Laboratory of Bio-resources, Shaanxi University of Technology, Hanzhong 723001, China.
| | - Lidia Skuza
- Institute of Biology, Centre for Molecular Biology and Biotechnology, University of Szczecin, Szczecin 71-415, Poland
| | - Shuhe Wei
- Key Laboratory of Pollution Ecology and Environment Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China.
| |
Collapse
|
3
|
Li X, Li X, Li Y, Dai X, Zhang Q, Zhang M, Zhang Z, Tao Y, Chen W, Zhang M, Zhou X, Yang S, Ma Y, Zhran M, Zou X. Improved immobilization of soil cadmium by regulating soil characteristics and microbial community through reductive soil disinfestation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 778:146222. [PMID: 33714838 DOI: 10.1016/j.scitotenv.2021.146222] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 02/25/2021] [Accepted: 02/26/2021] [Indexed: 06/12/2023]
Abstract
Cadmium (Cd) contamination arising from industrialization has attracted increasing attention in recent years. Reductive soil disinfestation (RSD) as an effective agricultural practice has been widely applied for soil sterilization. However, there is little research regarding RSD affecting Cd immobilization. Here, five treatments, namely untreated soil (CK), flooding-treated soil (FL), RSD with 2% ethyl alcohol (EA), 2% sugarcane bagasse (SB), and 2% bean dregs (BD) were designed to detect their performance for Cd immobilization in contaminated soils, and the change of soil properties and microbial communities were monitored. The results revealed that pH significantly increased in FL and RSD-treated soils, but was negatively correlated with the exchangeable fraction of Cd (EX-Cd), while Oxidation-Reduction Potential (Eh) significantly decreased in FL and RSD-treated soils, and was positively correlated with EX-Cd. BD treatment might contribute to the increase of CaCO3 as shown by X-Ray Diffractomer analysis and strongly decreased the EX-Cd in the soil, but increased the relative abundances of Firmicutes, Planctomycetes, Acidobacteria, and Gemmatimonadetes, which may promote Fe (III) reduction or induce resistance to Cd. Bacterial communities at the phylum and genus levels were closely related to Cd fraction. The FL and RSD treatments moderately altered bacterial specific functions, including iron respiration, which may contribute to remediation of Cd-polluted soil by Fe (III) reduction. Field experiments were conducted to confirm that BD treatment resulted in a significant increase in pH whereas the content of total available Cd was reduced in soils. Compared to the control, concentration of total available Cd of red amaranth, sweet potato, towel gourd, and cowpeas were reduced by approximately 46%, 74%, 72%, and 76% in a BD-treated field, respectively. Our study highlights the potential of RSD as an effective method for Cd immobilization in contaminated soils by improving soil characteristics and altering the composition of the microbial community.
Collapse
Affiliation(s)
- Xin Li
- Institute of Vegetable Research, Hunan Academy of Agricultural Science, Changsha 410000, China
| | - Xuefeng Li
- Institute of Vegetable Research, Hunan Academy of Agricultural Science, Changsha 410000, China
| | - Yueyue Li
- Institute of Vegetable Research, Hunan Academy of Agricultural Science, Changsha 410000, China
| | - Xiongze Dai
- Hunan Agricultural University, Changsha 410000, China
| | - Qingzhuang Zhang
- Institute of Vegetable Research, Hunan Academy of Agricultural Science, Changsha 410000, China
| | - Mi Zhang
- Institute of Vegetable Research, Hunan Academy of Agricultural Science, Changsha 410000, China
| | - Zhuqing Zhang
- Institute of Vegetable Research, Hunan Academy of Agricultural Science, Changsha 410000, China
| | - Yu Tao
- Institute of Vegetable Research, Hunan Academy of Agricultural Science, Changsha 410000, China
| | - Wenchao Chen
- Institute of Vegetable Research, Hunan Academy of Agricultural Science, Changsha 410000, China
| | - Mingxing Zhang
- Institute of Vegetable Research, Hunan Academy of Agricultural Science, Changsha 410000, China
| | - Xiangyu Zhou
- Institute of Vegetable Research, Hunan Academy of Agricultural Science, Changsha 410000, China
| | - Sha Yang
- Institute of Vegetable Research, Hunan Academy of Agricultural Science, Changsha 410000, China
| | - Yanqing Ma
- Department of Agriculture and Rural Affairs of Hunan Province, Changsha 410000, China
| | - Mostafa Zhran
- Soil and Water Research Department, Nuclear Research Center, Atomic Energy Authority, Abou-Zaabl 13759, Egypt
| | - Xuexiao Zou
- Institute of Vegetable Research, Hunan Academy of Agricultural Science, Changsha 410000, China; Hunan Agricultural University, Changsha 410000, China.
| |
Collapse
|
4
|
Abstract
Humin is the waste residue from the process of preparing humic acid, which accounts for a large proportion of the raw material (weathered coal humic acid). Its Cd(II) adsorption performance is far inferior to that of humic acid. How to regenerate humin is of great significance to the low-cost treatment of Cd(II) pollution in wastewater. In this study, humin was modified by hyperbranched polyethyleneimine to enhance the adsorption capacity for Cd(II). Fourier transform infrared spectroscopy and the X-ray photoelectron spectrometer showed that hyperbranched polyethyleneimine was grafted to the surface of humin. Flame atomic absorption spectroscopy showed that the saturated Cd(II) adsorption capacity of the modified humin was increased to 11.975 mg/g, which is about 5 times than that of humin and is also higher than that of humic acid. The adsorption kinetics, adsorption isotherm, and thermodynamic properties of humic acid, humin, and modified humin were also studied. This study may provide a foundation for research utilizing natural resources to reduce heavy metal pollution in the environment.
Collapse
|
5
|
Xu L, Dai H, Skuza L, Wei S. Optimal voltage and treatment time of electric field with assistant Solanum nigrum L. cadmium hyperaccumulation in soil. CHEMOSPHERE 2020; 253:126575. [PMID: 32268251 DOI: 10.1016/j.chemosphere.2020.126575] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 03/16/2020] [Accepted: 03/19/2020] [Indexed: 06/11/2023]
Abstract
We have attempted to obtain optimal conditions of direct current electrical field with switching polarity to increase Cd accumulation of the hyperaccumulator Solanum nigrum L. from soil. The effects of different voltages and treatment times on S. nigrum accumulating Cd were determined. The results showed that Cd concentration in S. nigrum under all electrical field conditions were significantly higher (p < 0.05) than that of the CK. The Cd concentration in shoot and root of treatment T3 (3 V cm-1) were higher than the equal results of treatment T2 (2 V cm-1) and T1 (1 V cm-1) under the same condition of 6 h d-1 treatment time. In different treatments concerning time of T1 (6 h d-1), T4 (10 h d-1) and T5 (14 h d-1) under same voltage of 1 V cm-1, the S. nigrum Cd concentration were with similar trend to the different voltage treatments (T5 with the highest Cd concentration). These results might be caused by positive change trends of pH, EC and extractable Cd concentration in soil. However, the S. nigrum biomasses of T3 were the lowest and the highest biomass happened in treatment of T4. Finally, the highest Cd accumulation in S. nigrm (μg pot-1) was the T4 with the condition of 1 V cm-1 and 10 h d-1, which was also the optimal voltage and treatment time of the electric field. The optimal conditions were important references in the practice of combined use of electrokinetic remediation and phytoremediation.
Collapse
Affiliation(s)
- Lei Xu
- Key Laboratory of Pollution Ecology and Environment Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Huiping Dai
- College of Biological Science & Engineering, Shaanxi Province Key Laboratory of Bio-resources, Shaanxi University of Technology, Hanzhong, 723001, China.
| | - Lidia Skuza
- Institute of Biology, University of Szczecin, Szczecin, 71-415, Poland
| | - Shuhe Wei
- Key Laboratory of Pollution Ecology and Environment Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China.
| |
Collapse
|
6
|
Xu L, Dai H, Skuza L, Wei S. The effects of different electric fields and electrodes on Solanum nigrum L. Cd hyperaccumulation in soil. CHEMOSPHERE 2020; 246:125666. [PMID: 31896016 DOI: 10.1016/j.chemosphere.2019.125666] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2019] [Revised: 12/08/2019] [Accepted: 12/12/2019] [Indexed: 06/10/2023]
Abstract
Electrokinetics is a new attempt of strengthening hyperaccumulator Solanum nigrum L. Cd extraction. The effects of different electric fields and electrodes on S. nigrum accumulating Cd among of four electric field conditions (1 V cm-1) and two electrodes were determined. The results showed that the AC electric field significantly stimulated (p < 0.05) the growth of S. nigrum, and the biomass increased nearly by 40% compared with the control, while the DC electric field (including the switching polarity) had no significant effect. Electric field significantly increased (p < 0.05) Cd concentration in S. nigrum and the highest one was recorded for the DC electric field with switching polarity. S. nigrum Cd accumulation (ug pot-1) was the highest under the AC electric field, which was nearly 70% higher compared to the control. The innovation found was that the role of biomass enhancement for S. nigrum accumulating Cd (ug pot-1) was the first and increased Cd concentration was secondary under AC electrical field, which might be relative with S. nigrum is a weed species. Basically, there was no significant difference between the graphite and stainless steel electrode, but under AC electric field conditions, Cd accumulation of S. nigrum was significantly higher (p < 0.05) than stainless steel electrode, which is worthy of further revelation besides of statistic factor. In general, the accumulation (ug pot-1) of Cd by S. nigrum was the highest under the AC electric field, which was a very important reference for the electrokinetic conditions to be used in the practice of phytoremediation.
Collapse
Affiliation(s)
- Lei Xu
- Key Laboratory of Pollution Ecology and Environment Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China; University of Chinese Academy of Sciences, Beijing, 100039, China
| | - Huiping Dai
- College of Biological Science & Engineering, Shaanxi Province Key Laboratory of Bio-resources, Shaanxi University of Technology, Hanzhong, 723001, China.
| | - Lidia Skuza
- Institute of Biology, University of Szczecin, Szczecin 71-415, Poland
| | - Shuhe Wei
- Key Laboratory of Pollution Ecology and Environment Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China.
| |
Collapse
|
7
|
Chen Y, Yang Z, Zhang Q, Fu D, Chen P, Li R, Liu H, Wang Y, Liu Y, Lv W, Liu G. Effect of tartaric acid on the adsorption of Pb (Ⅱ) via humin: Kinetics and mechanism. J Taiwan Inst Chem Eng 2020. [DOI: 10.1016/j.jtice.2019.11.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
8
|
Ma Q, Li J, Lee CCC, Long X, Liu Y, Wu QT. Combining potassium chloride leaching with vertical electrokinetics to remediate cadmium-contaminated soils. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2019; 41:2081-2091. [PMID: 30838487 DOI: 10.1007/s10653-019-00259-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 01/30/2019] [Indexed: 06/09/2023]
Abstract
This study evaluated the feasibility of combining potassium chloride (KCl) leaching and electrokinetic (EK) treatment for the remediation of cadmium (Cd) and other metals from contaminated soils. KCl leaching was compared at three concentrations (0.2%, 0.5%, and 1% KCl). EK treatment was conducted separately to migrate the metals in the topsoil to the subsoil. The combined approach using KCl leaching before or after EK treatment was compared. For the single vertical EK treatment, the removal of Cd, lead (Pb), copper (Cu) and zinc (Zn) from the topsoil (0-20 cm) was 9.38%, 4.80%, 0.95%, and 10.81%, respectively. KCl leaching at 1% KCl removed 84.06% Cd, 9.95% Pb, 4.34% Cu, and 19.93% Zn from the topsoil, with higher removal efficiency than that of the 0.2% and 0.5% KCl leaching treatments. By combining the KCl leaching and EK treatment, the removal efficiency of heavy metals improved, in particular for the 1% KCl + EK treatment, where the removal rate of Cd, Pb, Cu, and Zn from the upper surface soil reached 97.79%, 17.69%, 14.37%, and 41.96%, respectively. Correspondingly, the soil Cd content decreased from 4 to 0.21 mg/kg, and was below the Chinese standard limit of 0.3 mg/kg soil. These results indicate that 1% KCl + EK treatment is a good combination technique to mitigate Cd pollution from contaminated soils used for growing rice and leafy vegetables.
Collapse
Affiliation(s)
- Qiang Ma
- Key Laboratory on Soil Environment and Waste Reuse in Agriculture of Guangdong Higher Education Institutes, College of Natural Resources and Environment, South China Agricultural University, Guangzhou, 510642, China
| | - Jun Li
- Key Laboratory on Soil Environment and Waste Reuse in Agriculture of Guangdong Higher Education Institutes, College of Natural Resources and Environment, South China Agricultural University, Guangzhou, 510642, China
| | - Charles C C Lee
- School of Environmental and Life Sciences, University of Newcastle (Australia) Singapore, 6 Temasek Blvd, Singapore, 038986, Singapore
| | - Xinxian Long
- Key Laboratory on Soil Environment and Waste Reuse in Agriculture of Guangdong Higher Education Institutes, College of Natural Resources and Environment, South China Agricultural University, Guangzhou, 510642, China
| | - Yongmao Liu
- Inner Mongolia Research Institute of Metallurgy, Hohhot, 010010, China
| | - Qi-Tang Wu
- Key Laboratory on Soil Environment and Waste Reuse in Agriculture of Guangdong Higher Education Institutes, College of Natural Resources and Environment, South China Agricultural University, Guangzhou, 510642, China.
| |
Collapse
|
9
|
Huang T, Zhang S, Liu L. Immobilization of trace heavy metals in the electrokinetics-processed municipal solid waste incineration fly ashes and its characterizations and mechanisms. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2019; 232:207-218. [PMID: 30472564 DOI: 10.1016/j.jenvman.2018.11.051] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2018] [Revised: 11/12/2018] [Accepted: 11/14/2018] [Indexed: 06/09/2023]
Abstract
The mass production of municipal solid waste incineration (MSWI) fly ashes has caused severe concerns in regarding to the inherently ecological harm and the decreasing landfilling space. To relieve the heavy metal contamination into the environment and complete a closed-loop electrokinetics (EK), the sequential effects of electrokinetics and alkali activating solidification/stabilization (S/S) technique on the immobilization of HMs in the remnant of MSWI fly ashes were investigated in the research. The compressive strength for the remnant-based solidified product at the proposing time of 18 days was 2.58 MPa, 104.76% higher than that of the MWSI-based specimen with the optimal curing parameters being adopted for the production of the solidified matrices. The leaching concentrations of Zn, Pb, and Cu were 9.74, 0.21, and 0.75 mg/L, correspondingly reduced by 57.84%, 80.19%, and 17.58%, respectively. The opposite correlation between the compressive strength and the leaching concentration was demonstrated for both two groups of the curing samples. The mechanism results showed that the electrokinetics had significantly changed the micromorphology characteristics of MSWI fly ashes and distinctly affected the whole curing process. The cementation and geo-polymerization were comprehensively determined as two of main mechanisms for the immobilization of HMs in the curing matrices.
Collapse
Affiliation(s)
- Tao Huang
- School of Chemistry and Materials Engineering, Changshu Institute of Technology, 215500, China.
| | - Shuwen Zhang
- Nuclear Resources Engineering College, University of South China, 421001, China.
| | - Longfei Liu
- School of Chemistry and Materials Engineering, Changshu Institute of Technology, 215500, China
| |
Collapse
|
10
|
Gu YY, Zhao C, Li H, An H. The enhancement of synthesized wastewater on non-uniform electrokinetic remediation of a Cd-spiked natural clayey soil. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:1103-1114. [PMID: 29079978 DOI: 10.1007/s11356-017-0491-3] [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: 05/31/2017] [Accepted: 10/16/2017] [Indexed: 06/07/2023]
Abstract
It is usually very difficult to achieve satisfactory extraction efficiencies in electrokinetic remediation of heavy metal-contaminated soils of high acid/base buffer capacity. Enhancement agent is often required. In this study, synthesized citric acid industrial wastewater (CAIW) is used as the enhancement agent to remediate cadmium-spiked natural clayey soil from Shanghai, China. Four electrokinetic extraction experiments were carried out to evaluate the enhancement effects of CAIW on the remediation of metal-spiked clayed soil of high buffer capacity and the effects of treatment time and initial cadmium concentration on the migration of cadmium in the specimen. The results of electrokinetic experiments indicated that CAIW can efficiently enhance the transport of cadmium in comparison with HNO3 of the same pH. Cadmium mobilization was enhanced with prolonged treatment time from 104 to 261.2 h, but the average cadmium removal efficiency was not significantly enhanced. A non-uniform cadmium distribution in the specimen was observed after the enhanced electrokinetic experiments due to the localized electrical gradients with an electrical gradient of approximately 1 V/cm and a ratio of the distance between electrodes of the same polarity to the outer diameter of electrode of 2.8 (50:18 mm).
Collapse
Affiliation(s)
- Ying-Ying Gu
- Department of Environmental & Safety Engineering, China University of Petroleum (East China), Qingdao, 266580, China.
| | - Chaocheng Zhao
- Department of Environmental & Safety Engineering, China University of Petroleum (East China), Qingdao, 266580, China
| | - Hongjiang Li
- Qingdao Water Group Co. Ltd., Qingdao, 266002, China
| | - Hui An
- Department of Environmental & Safety Engineering, China University of Petroleum (East China), Qingdao, 266580, China
| |
Collapse
|
11
|
Huang B, Chi G, Chen X, Shi Y. Mild electrokinetic treatment of cadmium-polluted manure for improved applicability in greenhouse soil. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:24011-24018. [PMID: 28884455 DOI: 10.1007/s11356-017-0058-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 08/30/2017] [Indexed: 06/07/2023]
Abstract
Applications of cadmium (Cd) and salinity-containing manures contribute to Cd pollution and salinization in greenhouse soils. In this study, chicken manure polluted with Cd (5.6 mg/kg) was mildly electrokinetically treated (0.25 V/cm) for 48 h with intermittent replacement of catholyte with 20 mM acetic acid solution to remove Cd and salinity for application without need of post-treatment in greenhouse soil. The electrokinetic treatment created pH conditions mainly ranging from 5.0 to 8.0 within the manure for minimizing re-precipitation of desorbed Cd and evaporative loss of ammonium. However, without manure pre-acidification, electrokinetic treatment resulted in negligible removal of total Cd but 61.7% of increase in the small fraction of exchangeable Cd, due to poor desorption but enhanced formation of exchangeable Cd. In contrast, manure pre-acidification with 20 mM acetic acid favored Cd desorption, leading to electrokinetic removal of exchangeable, carbonate-bound, and total Cd by 32.2%, 34.5%, and 14.5%, respectively. Mild electrokinetic treatment of manure with and without pre-acidification resulted in similar removal of salinity (72.3% and 68.0%), similar pH condition (7.2 and 7.4), and basically same evaporative loss of ammonium (14.6% and 14.2%). Overall, the mild electrokinetic treatment considerably lowered the risk of Cd and the salinity from the pre-acidified manure for improved applicability in greenhouse soil, and more studies are needed to enhance the performance of electrokinetic Cd removal from manure.
Collapse
Affiliation(s)
- Bin Huang
- Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, No. 72 Wenhua Road, Shenyang, Liaoning Province, 110016, China.
| | - Guangyu Chi
- Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, No. 72 Wenhua Road, Shenyang, Liaoning Province, 110016, China
| | - Xin Chen
- Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, No. 72 Wenhua Road, Shenyang, Liaoning Province, 110016, China
| | - Yi Shi
- Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, No. 72 Wenhua Road, Shenyang, Liaoning Province, 110016, China
| |
Collapse
|