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Wang T, Liu Y, Liu B. The pH-sensitve oxygenation of FeS: Mineral transformation and immobilization of Cr(VI). Water Res 2023; 233:119722. [PMID: 36801571 DOI: 10.1016/j.watres.2023.119722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 12/25/2022] [Accepted: 02/06/2023] [Indexed: 06/18/2023]
Abstract
Iron sulfide (FeS) has been widely used to reduce toxic Cr(VI) into Cr(III) in anoxic aquatic environments, where pH could strongly influence Cr(VI) removal. However, it remains unclear how pH regulates the fate and transformation of FeS under oxic conditions and the immobilization of Cr(VI). The results of this study showed that typical pH conditions of natural aquatic environment significantly affected the mineral transformation of FeS. Under acidic conditions, FeS was principally transformed to goethite, amarantite, and elemental sulfur with minor lepidocrocite through proton-promoted dissolution and oxidation. Instead, under basic conditions, the main products were lepidocrocite and elemental sulfur via surface-mediated oxidation. In typical acidic or basic aquatic environment, the pronounced pathway for the oxygenation of FeS solids may alter their ability to remove Cr(VI). Longer oxygenation impeded Cr(VI) removal at acidic pH, and a decreasing ability to reduce Cr(VI) caused a drop in Cr(VI) removal performance. Cr(VI) removal decreased from 733.16 to 36.82 mg g-1 with the duration of FeS oxygenation increasing to 5760 min at pH 5.0. In contrast, newly generated pyrite from brief oxygenation of FeS improved Cr(VI) reduction at basic pH, followed by a drop in Cr(VI) removal performance due to the impaired reduction capacity with increasing to the complete oxygenation. Cr(VI) removal increased from 669.58 to 804.83 mg g-1 with increasing oxygenation time to 5 min and then decreased to 26.27 mg g-1 after the full oxygenation for 5760 min at pH 9.0. These findings provide insight into the dynamic transformation of FeS in oxic aquatic environments with various pHs and the impact on Cr(VI) immobilization.
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Affiliation(s)
- Tao Wang
- State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China; Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment of Ministry of Education, Chongqing University, Chongqing 400044, China
| | - Yuanyuan Liu
- State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China; Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment of Ministry of Education, Chongqing University, Chongqing 400044, China.
| | - Bin Liu
- State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China; Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment of Ministry of Education, Chongqing University, Chongqing 400044, China
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Peng Y, Xiao D, Yu G, Feng Y, Li J, Zhao X, Tang Y, Wang L, Zhang Q. Effect of an eco-friendly o/w emulsion stabilized with amphiphilic sodium alginate derivatives on lambda-cyhalothrin adsorption-desorption on natural soil minerals. J Environ Sci (China) 2019; 78:230-238. [PMID: 30665641 DOI: 10.1016/j.jes.2018.09.025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Revised: 09/29/2018] [Accepted: 09/30/2018] [Indexed: 06/09/2023]
Abstract
The effects of amphiphilic O/W emulsions, stabilized by the alkyl polyglycoside (APG) or cholesterol-grafted sodium alginate (CSAD)/APG systems, on lambda-cyhalothrin adsorption/desorption mechanisms on natural soil minerals (i.e., illite and kaolinite) were investigated. Sorption and desorption of lambda-cyhalothrin onto soil minerals was studied via batch equilibration to give insight into the adsorption equilibrium, kinetics, and thermodynamics of lambda-cyhalothrin adsorption onto minerals. The results indicate the following: (i) The adsorption processes for the APG system and CSAD/APG system include: rapid adsorption, slow adsorption, and adsorption equilibrium. The adsorption kinetics of pesticide on illite and kaolinite are in accordance with the Ho and McKay model, and the adsorption isotherm conforms to the Freundlich model. In addition, the adsorption processes of pesticide for the two systems on minerals were spontaneous and feasible (ΔG0 < 0), endothermic (ΔH0 > 0), and mainly involved chemical bonding (ΔH0 > 60). (ii) The equilibrium adsorption percentages of the pesticide on illite for the APG system and CSAD/APG system were 42.4% and 64.8%, and the corresponding equilibrium adsorption percentages on kaolinite were 40.8% and 61.8%, respectively. Moreover, the pesticide adsorption rate K2-CSAD/APG was faster than K2-APG, and its adsorption capacity Kf-CSAD/APG was greater than Kf-APG. Meanwhile, the pesticide desorption Kfd in the CSAD/APG system was smaller than that in the APG system. As a result, this eco-friendly O/W emulsion based on amphiphilic sodium alginate derivatives might provide a green pesticide formulation, since it could reduce the amount of lambda-cyhalothrin entering aquatic systems to threaten non-target fish and invertebrate species.
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Affiliation(s)
- Yang Peng
- Key Laboratory of Advanced Materials of Tropical Island Resources, Ministry of Education, College of Materials and Chemical Engineering, Hainan University, 58 Renmin Road, Haikou 570228, Hainan Province, China
| | - Dunchao Xiao
- Key Laboratory of Advanced Materials of Tropical Island Resources, Ministry of Education, College of Materials and Chemical Engineering, Hainan University, 58 Renmin Road, Haikou 570228, Hainan Province, China
| | - Gaobo Yu
- Key Laboratory of Advanced Materials of Tropical Island Resources, Ministry of Education, College of Materials and Chemical Engineering, Hainan University, 58 Renmin Road, Haikou 570228, Hainan Province, China
| | - Yuhong Feng
- Key Laboratory of Advanced Materials of Tropical Island Resources, Ministry of Education, College of Materials and Chemical Engineering, Hainan University, 58 Renmin Road, Haikou 570228, Hainan Province, China.
| | - Jiacheng Li
- Key Laboratory of Advanced Materials of Tropical Island Resources, Ministry of Education, College of Materials and Chemical Engineering, Hainan University, 58 Renmin Road, Haikou 570228, Hainan Province, China.
| | - Xinyu Zhao
- Key Laboratory of Advanced Materials of Tropical Island Resources, Ministry of Education, College of Materials and Chemical Engineering, Hainan University, 58 Renmin Road, Haikou 570228, Hainan Province, China
| | - Yiyuan Tang
- Key Laboratory of Advanced Materials of Tropical Island Resources, Ministry of Education, College of Materials and Chemical Engineering, Hainan University, 58 Renmin Road, Haikou 570228, Hainan Province, China
| | - Longzheng Wang
- Key Laboratory of Advanced Materials of Tropical Island Resources, Ministry of Education, College of Materials and Chemical Engineering, Hainan University, 58 Renmin Road, Haikou 570228, Hainan Province, China
| | - Quan Zhang
- Key Laboratory of Advanced Materials of Tropical Island Resources, Ministry of Education, College of Materials and Chemical Engineering, Hainan University, 58 Renmin Road, Haikou 570228, Hainan Province, China
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