1
|
Sun Q, Yang H, Zhao T. Multistage stabilization of Cd, Pb, Zn, Cu and As in contaminated soil by phosphorus-coated nZVI layered composite materials: characteristics, process and mechanism. JOURNAL OF HAZARDOUS MATERIALS 2024; 476:134991. [PMID: 38909473 DOI: 10.1016/j.jhazmat.2024.134991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Revised: 06/17/2024] [Accepted: 06/19/2024] [Indexed: 06/25/2024]
Abstract
This study developed a shell-like slow-release material, PF@ST/Fe-0.5, by encapsulating nanoscale zero-valent iron composites (NZC) with phosphate fertilizer (PF) and a starch binder (ST). The material dissolved in soil in stages, first releasing P and Ca to increase the soil pH from 4.95 to 7.14. This was followed by the formation of phosphates and hydroxides precipitates with Pb, Cu, Zn, and Cd in soil, reducing their bioavailable forms by 81.73 %, 79.58 %, 91.05 %, and 86.47 %, respectively. The process also involved the competitive adsorption between PO43-/HPO42- and arsenate/arsenite led to the release of specifically adsorbed arsenic, increasing the probability of reaction with the material. Afterwards, the exposure of the NZC core reacted with arsenate/arsenite to form ferric arsenates, thus reducing the content of bioavailable arsenic in the soil by 73.57 %. Excess PO43- and alkali metal cations were captured and mineralized by the iron (hydro) oxides and reactive silicates in NZC, enhancing the remediation effect. Furthermore, the wet-dry alternation test had demonstrated the adaptability of PF@ST/Fe-0.5 to the rainy dry-wet soil environment in Yunnan, which enabled the bioavailable content of As, Pb, Cu, Zn, and Cd decreased by 71.2 %, 94.8 %, 84.1 %, 79.8 %, and 83.9 %, respectively. The layered structure minimized internal reactive substance consumption and protected the internal nZVI from oxidation. The phased release of phosphate and Fe0 stabilized Pb, Cu, Zn, and Cd, enhancing As stabilization and providing a new perspective for the synchronous stabilization of soil contaminated.
Collapse
Affiliation(s)
- Qiwei Sun
- School of Civil and Resource Engineering, University of Science & Technology Beijing, Beijing 100083, China; Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing 100083, China; Key Laboratory of the Ministry of Education of China for High-efficient Mining and Safety of Metal Mines, University of Science and Technology Beijing, Beijing 100083, China
| | - Huifen Yang
- School of Civil and Resource Engineering, University of Science & Technology Beijing, Beijing 100083, China; Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing 100083, China.
| | - Tong Zhao
- School of Civil and Resource Engineering, University of Science & Technology Beijing, Beijing 100083, China; Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing 100083, China; Key Laboratory of the Ministry of Education of China for High-efficient Mining and Safety of Metal Mines, University of Science and Technology Beijing, Beijing 100083, China
| |
Collapse
|
2
|
The Impacts of Phosphorus-Containing Compounds on Soil Microorganisms of Rice Rhizosphere Contaminated by Lead. DIVERSITY 2023. [DOI: 10.3390/d15010069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The cost effectiveness of using exogenous phosphorus to remediate heavy metals in soil, which would alter the structure of the soil microbial community, had been widely acknowledged. In the present study, phospholipid fatty acid (PLFA) technology was taken as the breakthrough point, and rhizosphere soil microorganisms in different growth stages (jointing stage and maturity stage) of Minghui 86 (MH) and Yangdao No.6 (YD) rice were taken as the research objects. As revealed by the results, the rhizosphere soil microorganisms of MH and YD had distinct sensitivities to exogenous phosphorus and had a certain inhibitory effect on MH and YD enhancement. The sensitivity of rice root soil microorganisms to exogenous phosphorus also varied in different growth stages of rice. Bacteria were the dominant microorganism in the soil microbial community of rice roots, and the gain of exogenous phosphorus had a certain impact on the structure of the two soil microbial communities. Through analysis of the microbial community characteristics of MH rice and YD soil after adding exogenous phosphorus, further understanding was attained with respect to the effect of exogenous phosphorus on the microbial community characteristics of rice rhizosphere soil and the impact thereof on ecological functions.
Collapse
|
3
|
Yang Z, Gong H, He F, Repo E, Yang W, Liao Q, Zhao F. Iron-doped hydroxyapatite for the simultaneous remediation of lead-, cadmium- and arsenic-co-contaminated soil. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 312:119953. [PMID: 36028081 DOI: 10.1016/j.envpol.2022.119953] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 08/08/2022] [Accepted: 08/08/2022] [Indexed: 06/15/2023]
Abstract
Since lead, cadmium and arsenic have completely opposite chemical behaviors, it is very difficult to stabilize all these three heavy metals simultaneously. Herein, a novel iron-doped hydroxyapatite composite (Fe-HAP) was developed via an ultrasonic-assisted microwave hydrothermal method for the simultaneous remediation of lead-, cadmium-, and arsenic-co-contaminated soil in Hunan Province, South China. Using DTPA/sodium bicarbonate extractant to extract bioavailable Pb, Cd and As in soil after Fe-HAP remediation for 60 days, the immobilization efficiencies were 79.77%, 51.3% and 37.5% for Pb, Cd and As, respectively. The soil extractable and exchangeable fractions of Pb, Cd and As decreased significantly. In batch experiments, the adsorption kinetics of Pb, Cd and As on Fe-HAP were well described by pseudo-second-order models, indicating that the adsorption is controlled by chemisorption. In the Langmuir adsorption isotherm, the maximum adsorption capacities of Cd2+ and As(V) were 476.2 mg g-1 and 195.69 mg g-1, respectively, while Pb2+ fit the Freundlich model better. The XRD, SEM and XPS analyses indicated that Fe-HAP formed stable minerals of Pb5(PO4)3OH, Cd3(PO4)2·4H2O, Cd(OH)2 and Fe3(AsO4)2·6H2O with Pb, Cd and As. Overall, its facile and efficient immobilization performance indicate that Fe-HAP has potential for practical applications in integrative remediation of Pb-, Cd-, and As- co-contaminated soil.
Collapse
Affiliation(s)
- Zhihui Yang
- School of Metallurgy and Environment, Central South University, Changsha, 410083, Hunan, China; Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Institute of Environmental Engineering, Central South University, Changsha, 410083, Hunan, China
| | - Hangyuan Gong
- School of Metallurgy and Environment, Central South University, Changsha, 410083, Hunan, China; Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Institute of Environmental Engineering, Central South University, Changsha, 410083, Hunan, China; Hunan Chemical Geological Engineering Exploration Institute Co., Ltd., Changsha, 410004, Hunan, China
| | - Fangshu He
- School of Metallurgy and Environment, Central South University, Changsha, 410083, Hunan, China; Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Institute of Environmental Engineering, Central South University, Changsha, 410083, Hunan, China
| | - Eveliina Repo
- Department of Separation Science, School of Engineering Science, Lappeenranta-Lahti University of Technology LUT, Yliopistonkatu 34, FI, 53850, Finland
| | - Weichun Yang
- School of Metallurgy and Environment, Central South University, Changsha, 410083, Hunan, China; Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Institute of Environmental Engineering, Central South University, Changsha, 410083, Hunan, China
| | - Qi Liao
- School of Metallurgy and Environment, Central South University, Changsha, 410083, Hunan, China; Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Institute of Environmental Engineering, Central South University, Changsha, 410083, Hunan, China
| | - Feiping Zhao
- School of Metallurgy and Environment, Central South University, Changsha, 410083, Hunan, China; Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Institute of Environmental Engineering, Central South University, Changsha, 410083, Hunan, China.
| |
Collapse
|