51
|
Fu QL, Blaney L, Zhou DM. Identifying Plant Stress Responses to Roxarsone in Soybean Root Exudates: New Insights from Two-Dimensional Correlation Spectroscopy. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:53-62. [PMID: 29240415 DOI: 10.1021/acs.jafc.7b04706] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Roxarsone (ROX) is an organoarsenic feed additive of increasing interest used in the poultry industry. Soybean responses to ROX stress were investigated in root exudates (REs) using two-dimensional correlation spectroscopy (2D-COS) with fluorescence and Fourier transform infrared spectra. Environmentally relevant ROX concentrations caused negligible toxicity to crop growth and photosynthesis activity but blackened soybean roots at high concentrations. 2D-COS analysis revealed that the protein-like fluorophore and C═C and C═O, aliphatic OH, and polysaccharide C-O-H moieties in soybean REs were most sensitive to ROX stress. Heterospectral 2D-COS results suggested that aromatic, amide I, quinone, ketone, and aliphatic functional groups were the foundational components of protein-like and short-wavelength excited humic-like fluorophores in soybean REs. Carboxyl and phenolic moieties were related to the long-wavelength excited humic-like fluorophore. Overall, 2D-COS combined with molecular-based spectral analysis of REs provided an innovative approach to characterize the physiological responses of crops to contaminants at sublethal levels.
Collapse
Affiliation(s)
- Qing-Long Fu
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences , Nanjing, Jiangsu 210008, People's Republic of China
- University of Chinese Academy of Sciences , Beijing 100049, People's Republic of China
| | - Lee Blaney
- Department of Chemical, Biochemical and Environmental Engineering, University of Maryland, Baltimore County , 1000 Hilltop Circle, Baltimore, Maryland 21250, United States
| | - Dong-Mei Zhou
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences , Nanjing, Jiangsu 210008, People's Republic of China
| |
Collapse
|
52
|
Yan X, Liu C, Zhong L, Wang J. Combining phytoremediation with soil flushing for arsenic removal from contaminated soil. INTERNATIONAL JOURNAL OF PHYTOREMEDIATION 2018; 20:1229-1235. [PMID: 31274022 DOI: 10.1080/15226514.2018.1460309] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Arsenic (As) contamination poses a high risk to public health in China. Remediation of soil As contamination is an urgent need. Development of more effective remediation technologies is crucial in order to achieve remediation goals. In this study, pot experiments were carried out to study the As removal effectiveness of planting Pteris vittata L. (P.v.) and Lolium multiflorum L. (L.m.) in combination with in situ soil flushing using monopotassium phosphate (KH2PO4) solutions. Results showed that planting P.v. and L.m. in combination with 8 days of KH2PO4 solution soil flushing achieved 35.20% and 52.93%. As removal efficiency in the rhizosphere soil, respectively, which was significantly higher than 9.14% removal from soil flushing alone. Results also indicated that planting P.v. and L.m. changed the speciation of As to labile form, facilitating As removal from soil. Growing P.v. with in situ KH2PO4 flushing was more effective in remediating As-contaminated agricultural soil; L.m. could not be used in place of P.v to achieve the same remediation efficiency. This research provides an important guidance on plant screening for phytoremediation in combination with in situ flushing to remediate As-contaminated soil.
Collapse
Affiliation(s)
- Xiulan Yan
- a Office of Environmental Geography and Human Health, Key Laboratory of Land Surface Pattern and Simulation , Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences , Beijing , China
| | - Chuchen Liu
- a Office of Environmental Geography and Human Health, Key Laboratory of Land Surface Pattern and Simulation , Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences , Beijing , China
- b University of Chinese Academy of Sciences , Beijing , China
| | - Lirong Zhong
- c Energy and Environment Directorate , Pacific Northwest National Laboratory , Richland , WA , USA
| | - Jianyi Wang
- a Office of Environmental Geography and Human Health, Key Laboratory of Land Surface Pattern and Simulation , Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences , Beijing , China
- b University of Chinese Academy of Sciences , Beijing , China
| |
Collapse
|
53
|
Cui JL, Zhao YP, Li JS, Beiyuan JZ, Tsang DCW, Poon CS, Chan TS, Wang WX, Li XD. Speciation, mobilization, and bioaccessibility of arsenic in geogenic soil profile from Hong Kong. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2018; 232:375-384. [PMID: 28966030 DOI: 10.1016/j.envpol.2017.09.040] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 09/08/2017] [Accepted: 09/09/2017] [Indexed: 05/25/2023]
Abstract
The behaviour of arsenic (As) from geogenic soil exposed to aerobic conditions is critical to predict the impact of As on the environment, which processes remain unresolved. The current study examined the depth profile of As in geologically derived subsoil cores from Hong Kong and investigated the mobilization, plant availability, and bioaccessibility of As in As-contaminated soil at different depths (0-45.8 m). Results indicated significant heterogeneity, with high levels of As in three layers of soil reaching up to 505 mg/kg at a depth of 5 m, 404 mg/kg at a depth of 15 m, and 1510 mg/kg at a depth of 27-32 m. Arsenic in porewater samples was <11.5 μg/L in the study site. X-ray absorption spectroscopy (XAS) indicated that main As species in soil was arsenate (As(V)), as adsorbed fraction to Fe oxides (41-69% on goethite and 0-8% on ferrihydrite) or the mineral form scorodite (30-57%). Sequential extraction procedure demonstrated that 0.5 ± 0.4% of As was exchangeable. Aerobic incubation experiments exhibited that a very small amount (0.14-0.48 mg/kg) of As was desorbed from the soil because of the stable As(V) complex structure on abundant Fe oxides (mainly goethite), where indigenous microbes partly (59 ± 18%) contributed to the release of As comparing with the sterilized control. Furthermore, no As toxicity in the soil was observed with the growth of ryegrass. The bioaccessibility of As was <27% in the surface soil using simplified bioaccessibility extraction test. Our systematic evaluation indicated that As in the geogenic soil profile from Hong Kong is relatively stable exposing to aerobic environment. Nevertheless, children and workers should avoid incidental contact with excavated soil, because high concentration of As was present in the digestive solution (<0.1-268 μg/L).
Collapse
Affiliation(s)
- Jin-Li Cui
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong
| | - Yan-Ping Zhao
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong
| | - Jiang-Shan Li
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong
| | - Jing-Zi Beiyuan
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong
| | - Daniel C W Tsang
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong
| | - Chi-Sun Poon
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong
| | - Ting-Shan Chan
- National Synchrotron Radiation Research Center, 101 Hsin-Ann Road, Hsinchu Science Park, Hsinchu 30076, Taiwan
| | - Wen-Xiong Wang
- Division of Life Science, The Hong Kong University of Science and Technology (HKUST), Clearwater Bay, Kowloon, Hong Kong
| | - Xiang-Dong Li
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
| |
Collapse
|
54
|
Han YH, Liu X, Rathinasabapathi B, Li HB, Chen Y, Ma LQ. Mechanisms of efficient As solubilization in soils and As accumulation by As-hyperaccumulator Pteris vittata. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2017; 227:569-577. [PMID: 28501771 DOI: 10.1016/j.envpol.2017.05.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 04/30/2017] [Accepted: 05/01/2017] [Indexed: 06/07/2023]
Abstract
Arsenic (As) in soils is of major environmental concern due to its ubiquity and carcinogenicity. Pteris vittata (Chinese brake fern) is the first known As-hyperaccumulator, which is highly efficient in extracting As from soils and translocating it to the fronds, making it possible to be used for phytoremediation of As-contaminated soils. In addition, P. vittata has served as a model plant to study As metabolisms in plants. Based on the recent advances, we reviewed the mechanisms of efficient As solubilization and transformation in rhizosphere soils of P. vittata and effective As uptake, translocation and detoxification in P. vittata. We also provided future research perspectives to further improve As phytoremediation by P. vittata.
Collapse
Affiliation(s)
- Yong-He Han
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu, 210046, China
| | - Xue Liu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu, 210046, China
| | - Bala Rathinasabapathi
- Horticultural Sciences Department, University of Florida, Gainesville, FL, 32611, United States
| | - Hong-Bo Li
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu, 210046, China
| | - Yanshan Chen
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu, 210046, China.
| | - Lena Q Ma
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu, 210046, China; Soil and Water Science Department, University of Florida, Gainesville, FL, 32611, United States.
| |
Collapse
|
55
|
Liu X, Fu JW, Tang N, da Silva EB, Cao Y, Turner BL, Chen Y, Ma LQ. Phytate induced arsenic uptake and plant growth in arsenic-hyperaccumulator Pteris vittata. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2017; 226:212-218. [PMID: 28432964 DOI: 10.1016/j.envpol.2017.04.021] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 04/10/2017] [Accepted: 04/10/2017] [Indexed: 06/07/2023]
Abstract
Phytate is abundant in soils, which is stable and unavailable for plant uptake. However, it occurs in root exudates of As-hyperaccumulator Pteris vittata (PV). To elucidate its effect on As uptake and growth, P. vittata were grown on agar media (63 μM P) containing 50 μM As and/or 50 or 500 μM phytate with non As-hyperaccumulator Pteris ensiformis (PE) as a congeneric control for 60 d. Phytate induced efficient As and P uptake, and enhanced growth in PV, but had little effects on PE. The As concentrations in PV fronds and roots were 157 and 31 mg kg-1 in As50+phytate50, 2.2- and 3.1-fold that of As50 treatment. Phosphorus uptake by PV was reduced by 27% in As treatment than the control (P vs. P+As) but increased by 73% comparing phytate500 to phytate500+As, indicating that PV effectively took up P from phytate. Neither As nor phytate affected Fe accumulation in PV, but phytate reduced root Fe concentration in PE (46-56%). As such, the increased As and P and the unsuppressed Fe uptake in PV probably promoted PV growth. Thus, supplying phytate to As-contaminated soils may promote As uptake and growth in PV and its phytoremediation ability.
Collapse
Affiliation(s)
- Xue Liu
- State Key Lab of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210023, China
| | - Jing-Wei Fu
- State Key Lab of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210023, China
| | - Ni Tang
- State Key Lab of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210023, China
| | - E B da Silva
- Soil and Water Science Department, University of Florida, Gainesville, FL 32611, United States
| | - Yue Cao
- State Key Lab of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210023, China
| | - Benjamin L Turner
- Smithsonian Tropical Research Institute, Balboa, Ancon, Republic of Panama
| | - Yanshan Chen
- State Key Lab of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210023, China.
| | - Lena Q Ma
- State Key Lab of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210023, China; Soil and Water Science Department, University of Florida, Gainesville, FL 32611, United States.
| |
Collapse
|
56
|
Fu JW, Liu X, Han YH, Mei H, Cao Y, de Oliveira LM, Liu Y, Rathinasabapathi B, Chen Y, Ma LQ. Arsenic-hyperaccumulator Pteris vittata efficiently solubilized phosphate rock to sustain plant growth and As uptake. JOURNAL OF HAZARDOUS MATERIALS 2017; 330:68-75. [PMID: 28212511 DOI: 10.1016/j.jhazmat.2017.01.049] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 01/23/2017] [Accepted: 01/25/2017] [Indexed: 06/06/2023]
Abstract
Phosphorus (P) is one of the most important nutrients for phytoremediation of arsenic (As)-contaminated soils. In this study, we demonstrated that As-hyperaccumulator Pteris vittata was efficient in acquiring P from insoluble phosphate rock (PR). When supplemented with PR as the sole P source in hydroponic systems, P. vittata accumulated 49% and 28% higher P in the roots and fronds than the -P treatment. In contrast, non-hyperaccumulator Pteris ensiformis was unable to solubilize P from PR. To gain insights into PR solubilization by plants, organic acids in plant root exudates were analyzed by HPLC. The results showed that phytic acid was the predominant (>90%) organic acid in P. vittata root exudates whereas only oxalic acid was detected in P. ensiformis. Moreover, P. vittata secreted more phytic acid in -P and PR treatments. Compared to oxalic acid, phytic acid was more effective in solubilizing PR, suggesting that phytic acid was critical for PR utilization. Besides, secretion of phytic acid by P. vittata was not inhibited by arsenate. Our data indicated that phytic acid played an important role in efficient use of insoluble PR by P. vittata, shedding light on using insoluble PR to enhance phytoremediation of As-contaminated soils.
Collapse
Affiliation(s)
- Jing-Wei Fu
- State Key Lab of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210023, China
| | - Xue Liu
- State Key Lab of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210023, China
| | - Yong-He Han
- State Key Lab of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210023, China
| | - Hanyi Mei
- State Key Lab of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210023, China; Faculty of Environmental Science and Engineering, South West Forestry University, Yunnan 650224, China
| | - Yue Cao
- State Key Lab of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210023, China
| | - Letuzia M de Oliveira
- Soil and Water Science Department, University of Florida, Gainesville, FL 32611, United States
| | - Yungen Liu
- Faculty of Environmental Science and Engineering, South West Forestry University, Yunnan 650224, China
| | - Bala Rathinasabapathi
- Horticultural Sciences Department, University of Florida, Gainesville, FL, 32611, United States
| | - Yanshan Chen
- State Key Lab of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210023, China.
| | - Lena Q Ma
- State Key Lab of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210023, China; Soil and Water Science Department, University of Florida, Gainesville, FL 32611, United States.
| |
Collapse
|
57
|
Liu X, Fu JW, Da Silva E, Shi XX, Cao Y, Rathinasabapathi B, Chen Y, Ma LQ. Microbial siderophores and root exudates enhanced goethite dissolution and Fe/As uptake by As-hyperaccumulator Pteris vittata. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2017; 223:230-237. [PMID: 28108165 DOI: 10.1016/j.envpol.2017.01.016] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 01/09/2017] [Accepted: 01/10/2017] [Indexed: 06/06/2023]
Abstract
Arsenic (As) in soils is often adsorbed on Fe-(hydro)oxides surface, rendering them more resistant to dissolution, which is undesirable for phytoremediation of As-contaminated soils. Arsenic hyperaccumulator Pteris vittata prefers to grow in calcareous soils where available Fe and As are low. To elucidate its mechanisms of acquiring Fe and As from insoluble sources in soils, we investigated dissolution of goethite with pre-adsorbed arsenate (AsV; As-goethite) in presence of four organic ligands, including two root exudates (oxalate and phytate, dominant in P. vittata) and two microbial siderophores (PG12-siderophore and desferrioxamine B). Their presence increased As solubilization from As-goethite from 0.03 to 0.27-5.33 mg L-1 compared to the control. The siderophore/phytate bi-ligand treatment released 7.42 mg L-1 soluble Fe, which was 1.2-fold that of the sum of siderophore and phytate, showing a synergy in promoting As-goethite dissolution. In the ligand-mineral-plant system, siderophore/phytate was most effective in releasing As and Fe from As-goethite. Moreover, the continuous plant uptake induced more As-goethite dissolution. The continued release of As and Fe significantly enhanced their plant uptake (from 0.01 to 0.43 mg plant-1 As and 2.7-14.8 mg plant-1 Fe) and plant growth (from 1.2 to 3.1 g plant-1 fw) in P. vittata. Since microbial siderophores and root exudates often coexist in soil rhizosphere, their synergy in enhancing dissolution of insoluble As-Fe minerals may play an important role in efficient phytoremediation of As-contaminated soils.
Collapse
Affiliation(s)
- Xue Liu
- State Key Lab of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210023, People's Republic of China
| | - Jing-Wei Fu
- State Key Lab of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210023, People's Republic of China
| | - Evandro Da Silva
- Horticultural Sciences Department, University of Florida, Gainesville, FL 32611, United States
| | - Xiao-Xia Shi
- State Key Lab of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210023, People's Republic of China
| | - Yue Cao
- State Key Lab of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210023, People's Republic of China
| | - Bala Rathinasabapathi
- Soil and Water Science Department, University of Florida, Gainesville, FL 32611, United States
| | - Yanshan Chen
- State Key Lab of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210023, People's Republic of China.
| | - Lena Q Ma
- State Key Lab of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210023, People's Republic of China; Horticultural Sciences Department, University of Florida, Gainesville, FL 32611, United States.
| |
Collapse
|
58
|
Das S, Chou ML, Jean JS, Yang HJ, Kim PJ. Arsenic-enrichment enhanced root exudates and altered rhizosphere microbial communities and activities in hyperaccumulator Pteris vittata. JOURNAL OF HAZARDOUS MATERIALS 2017; 325:279-287. [PMID: 27940117 DOI: 10.1016/j.jhazmat.2016.12.006] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 12/01/2016] [Accepted: 12/02/2016] [Indexed: 06/06/2023]
Abstract
Phytoremediation of arsenic (As)-contaminated soil by hyperaccumulator Pteris vittata is promising. A better understanding of the rhizosphere microbial dynamics that regulate As availability and plant growth is important to optimize the phytoremediation process. In this study, Illumina sequencing of 16S rRNA genes was applied to assess the rhizosphere microbial community structure of P. vittata. Microbial functionality was monitored by soil enzyme activities and MPN-PCR targeting genes of interest. Arsenic (100mgkg-1 AsV) addition to soil significantly increased DOC, root exudates, As and P uptake and the frond biomass of P. vittata. Moreover, As-enrichment significantly increased soil enzyme activities involved in N, P and S cycling and the gene abundance of As transforming bacteria, Fe- and S-reducing bacteria and N and C fixing bacteria in the rhizosphere of P. vittata. Together, the results revealed that the combined selective pressure of As and rhizosphere resulted in stimulation of microbial community, which most likely has a role in reductive dissolution of Fe and S, As and P mobilization, C degradation and fixation, and N fixation. These changes appeared to have a role in mitigation of As toxicity and to promote growth and the As uptake ability of P. vittata under As-enriched conditions.
Collapse
Affiliation(s)
- Suvendu Das
- Department of Earth Sciences, National Cheng Kung University, Tainan 70101, Taiwan; Institute of Agricultural Science and Life Science, Gyeongsang National University, Jinju 660-701, Republic of Korea
| | - Mon-Lin Chou
- Department of Earth Sciences, National Cheng Kung University, Tainan 70101, Taiwan
| | - Jiin-Shuh Jean
- Department of Earth Sciences, National Cheng Kung University, Tainan 70101, Taiwan.
| | - Huai-Jen Yang
- Department of Earth Sciences, National Cheng Kung University, Tainan 70101, Taiwan
| | - Pil Joo Kim
- Institute of Agricultural Science and Life Science, Gyeongsang National University, Jinju 660-701, Republic of Korea
| |
Collapse
|
59
|
Wan X, Lei M, Chen T, Yang J. Intercropped Pteris vittata L. and Morus alba L. presents a safe utilization mode for arsenic-contaminated soil. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 579:1467-1475. [PMID: 27908626 DOI: 10.1016/j.scitotenv.2016.11.148] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 11/21/2016] [Accepted: 11/21/2016] [Indexed: 06/06/2023]
Abstract
Intercropping technology provides income for owners of contaminated soil without increasing environmental risk. Therefore, intercropping of arsenic (As) hyperaccumulator Pteris vittata L. with economic crops is now widely utilized in slightly or moderately As-contaminated farmlands. However, the mechanisms for As mobilization and absorption within the intercropping system are still unclear. To clarify As mobilization and absorption within an intercropping system, portable X-ray fluorescence spectrometry and sequential extraction were utilized to detect the spatial distribution and speciation of As in an intercropped system of P. vittata and cash crop mulberry (Morus alba L.). Compared with the P. vittata monoculture, P. vittata intercropping had higher As concentration, which may have been caused by the efficient exploitation of a greater As source in soil. Compared with the M. alba monoculture, M. alba intercropping had lower As concentration, which may have been caused by the As depletion by P. vittata roots. Spatial distribution of As in the soil indicated a "valley" around the P. vittata roots in both monocultured and intercropped systems, implying that As was depleted around the P. vittata roots. Continuous As extraction confirmed that both P. vittata monoculture and P. vittata and M. alba intercropping can efficiently control the risk of As soil contamination. Moreover, the properties of M. alba leaves were further studied. Mulberry leaves in the intercropping system satisfied the national feed standards. Therefore, intercropping presents a safe utilization mode for As-contaminated soil and can increase the income from silkworm-rearing M. alba leaves, without extra environmental risk.
Collapse
Affiliation(s)
- Xiaoming Wan
- Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Mei Lei
- Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.
| | - Tongbin Chen
- Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Junxing Yang
- Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
| |
Collapse
|
60
|
Wang L, Putnis CV, King HE, Hövelmann J, Ruiz-Agudo E, Putnis A. Imaging Organophosphate and Pyrophosphate Sequestration on Brucite by in Situ Atomic Force Microscopy. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:328-336. [PMID: 27983815 DOI: 10.1021/acs.est.6b05456] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
In order to evaluate the organic phosphorus (OP) and pyrophosphate (PyroP) cycle and their fate in the environment, it is critical to understand the effects of mineral interfaces on the reactivity of adsorption and precipitation of OP and PyroP. Here, in situ atomic force microscopy (AFM) is used to directly observe the kinetics of coupled dissolution-precipitation on cleaved (001) surfaces of brucite [Mg(OH)2] in the presence of phytate, glucose-6-phosphate (G6P) and pyrophosphate, respectively. AFM results show that the relative order of contribution to mineral surface adsorption and precipitation is phytate > pyrophosphate > G6P under the same solution conditions and can be quantified by the induction time of OP/PyroP-Mg nucleation in a boundary layer at the brucite-water interface. Calculations of solution speciation during brucite dissolution in the presence of phytate or pyrophosphate at acidic pH conditions show that the solutions may reach supersaturation with respect to Mg5H2Phytate.6H2O as a Mg-phytate phase or Mg2P2O7 as a Mg-pyrophosphate phase that becomes thermodynamically stable before equilibrium with brucite is reached. This is consistent with AFM dynamic observations for the new phase formations on brucite. Direct nanoscale observations of the transformation of adsorption/complexation-surface precipitation, combined with spectroscopic characterizations and species simulations may improve the mechanistic understanding of organophosphate and pyrophosphate sequestration by mineral replacement reactions through a mechanism of coupled dissolution-precipitation occurring at mineral-solution interfaces in the environment.
Collapse
Affiliation(s)
- Lijun Wang
- College of Resources and Environment, Huazhong Agricultural University , Wuhan 430070, China
| | - Christine V Putnis
- Institut für Mineralogie, University of Münster , 48149 Münster, Germany
- Department of Chemistry, Curtin University , Perth, Western Australia 6845, Australia
| | - Helen E King
- Department of Earth Sciences, Utrecht University , 3584 CD Utrecht, The Netherlands
| | - Jörn Hövelmann
- Interface-Geochemistry, Geoforschungszentrum Potsdam, Telegrafenberg, 14473 Potsdam, Germany
| | - Encarnación Ruiz-Agudo
- Department of Mineralogy and Petrology, University of Granada , Fuentenueva s/n, Grenada 18071, Spain
| | - Andrew Putnis
- Institut für Mineralogie, University of Münster , 48149 Münster, Germany
- The Institute for Geoscience Research (TIGeR), Curtin University , Perth, Western Australia 6102, Australia
| |
Collapse
|