87 results on '"Dong-Xing Guan"'
Search Results
2. Rare earth elements in clay-sized fractions: Implications for weathering fingerprint from parent materials to soils
- Author
-
Xianming Zhang, Yuntao Jing, Wanfu Zhao, Yongjun Jiang, Dong-Xing Guan, Hongxia Du, Ying Qian, Fei Ye, and Wancang Zhao
- Subjects
Weathering ,Clay mineralogy ,Chemical analysis ,Rare earths ,Iron ,Science - Abstract
Rare earth elements (REEs) have gained attention as tracers of pedogenic processes over the last few decades. Clay-sized fractions (CSFs, < 2 μm) may play a crucial role in hosting REEs. To better understand the pedochemical signals of REEs in clay-sized phases, such as iron oxides and phyllosilicates, we analyzed REE speciation in CSFs of carbonate rocks (limestone), clastic rocks (sandstone and shale), and their derived saprolites. Our results quantified the REE content (41.2–144.6 mg kg−1) and speciation in CSFs of parent materials, revealing that REEs were primarily hosted in amorphous iron oxides (Feox1), followed by crystalline iron oxides (Feox2) and phyllosilicates. Compared to parent materials, saprolites derived from carbonate rocks exhibited more than a two-fold enrichment of REEs in major clay-sized phases, confirming the role of CSFs as REE sinks during carbonate rock weathering. Furthermore, the initial REE patterns of CSFs of carbonate rocks underwent alteration throughout the weathering process, likely due to water–mineral interactions. Our findings suggest that REEs in CSFs record the weathering fingerprint for soils derived from carbonate rocks, while they are indicative of provenance for soils originating from clastic rocks.
- Published
- 2024
- Full Text
- View/download PDF
3. Enhancing the quality and reputation of Soil & Environmental Health journal: 2024 updates
- Author
-
Lena Q. Ma, Kashif Hayat, Jing Wang, Maria Manzoor, Dong-Xing Guan, and Randy A. Dahlgren
- Subjects
Environmental sciences ,GE1-350 ,Public aspects of medicine ,RA1-1270 - Published
- 2024
- Full Text
- View/download PDF
4. Editorial: The role of essential trace elements in health and disease
- Author
-
Dong-Xing Guan, Chunguang Yang, and Jerome O. Nriagu
- Subjects
essential trace elements ,human health ,metabolic diseases ,maternal and perinatal health ,human cancers ,public health ,Public aspects of medicine ,RA1-1270 - Published
- 2024
- Full Text
- View/download PDF
5. Biochar-bacteria partnership based on microbially induced calcite precipitation improves Cd immobilization and soil function
- Author
-
Min Xu, Jing Ma, Xiao-Hong Zhang, Gang Yang, Lu-Lu Long, Chao Chen, Chun Song, Jun Wu, Peng Gao, and Dong-Xing Guan
- Subjects
Microbially induced calcite precipitation (MICP) ,Biochar-bacteria system ,Cd immobilization ,Carbonate ,Nitrogen cycle ,Environmental sciences ,GE1-350 ,Agriculture - Abstract
Highlights A biochar-bacteria (2B) system was constructed based on MICP. Cd was immobilized (23.6–45.8%) in the 2B system. 2B system facilitated the formation of insoluble otavite (CdCO3). Bacteria carrying the ureC gene were boosted to lower the Cd mobility. Graphical Abstract
- Published
- 2023
- Full Text
- View/download PDF
6. The Importance of Mineral Elements for Sustainable Crop Production
- Author
-
Dong-Xing Guan, Daniel Menezes-Blackburn, and Gang Li
- Subjects
n/a ,Agriculture - Abstract
By 2050, the global population is projected to reach 9 [...]
- Published
- 2024
- Full Text
- View/download PDF
7. Enhancing the quality and reputation of Soil & Environmental Health journal
- Author
-
Lena Q. Ma, Dong-Xing Guan, Pingfeng Yu, Zhongkui Luo, Jing Wang, and Kashif Hayat
- Subjects
Environmental sciences ,GE1-350 ,Public aspects of medicine ,RA1-1270 - Published
- 2023
- Full Text
- View/download PDF
8. Selenium contents, speciation and bioaccessibility of Se-enriched rice grains from Chinese markets
- Author
-
Jing-Yu Zeng, Dong-Xing Guan, Zhi-Hua Dai, Jia-Yi Chen, Wen-Jie Dong, Song Ding, and Lena Q. Ma
- Subjects
Human health ,Regional variation ,Se-enriched rice ,Modified physiologically-based extraction test ,Organic Se ,Selenium exposure ,Environmental sciences ,GE1-350 ,Public aspects of medicine ,RA1-1270 - Abstract
Diet intake accounts for >90% of selenium (Se) exposure in humans, with rice being the main source of Se intake for >60% of the Chinese population. In this study, 48 rice grain samples labeled Se-enriched were obtained from 22 major rice producing areas in China through online sources. Their total Se contents, Se speciation, and Se bioaccessibility were evaluated to provide a holistic view of Se-enriched rice in the market. The total Se contents were 0.006–0.951 μg g−1 (average 0.249 μg g−1), which showed great regional variations, with 73% of the samples satisfying the Se-enriched standard based on GB/T22499-2008 (0.04–0.30 mg kg−1). Over 80% of Se in the rice samples was organic Se species including selenomethionine, selenocysteine and methylselenocysteine, with selenomethionine being the main Se species, accounting for 61–98%. Based on a modified physiologically-based extraction test (MPBET), the Se bioaccessibility in 33 selected samples was 8.05–49.6% (28.6%) in the gastric phase and 18.1–117% (82.5%) in the intestinal phase. Further, Se bioaccessibility was positively correlated with organic Se (r = 0.89–0.93), but not with inorganic Se (selenite and selenate), suggesting that Se bioaccessibility depended on organic Se in these rice grains. The data call for re-evaluation of Se-enriched rice in the market. Further, the potential risk of long-term consumption of Se-enriched rice in the market towards human health should be studied.
- Published
- 2023
- Full Text
- View/download PDF
9. Comparison of in vitro strategies for predicting Dichlorodiphenyltrichloroethane (DDT) and its metabolites bioavailability from soils
- Author
-
Chao Li, Shen Xu, Dong-xing Guan, Xianxian Chen, and Huan He
- Subjects
In vitro assays ,DDT ,Mouse model ,Tenax ,Bioaccessibility ,Bioavailability ,Environmental pollution ,TD172-193.5 ,Environmental sciences ,GE1-350 - Abstract
In vitro strategies have widely been used to assess bioaccessibility of organic pollutants in soils. However, studies for comparing in vitro models with in vivo data are still limited. In this study, Dichlorodiphenyltrichloroethane (DDT) and its metabolites (called as DDTr) bioaccessibility in nine contaminated soils were measured using physiologically based extraction test (PBET), in vitro digestion model (IVD), and Deutsches Institut für Normung (DIN) with/without Tenax as an absorptive sink, and DDTr bioavailability was assessed using an in vivo mouse model. Whether or not Tenax was added, DDTr bioaccessibility significantly varied among three methods, suggesting that DDTr bioaccessibility depended on the in vitro method employed. Multiple linear regression analysis indicated that sink, intestinal incubation time and bile content are identified to be the dominant factors in controlling DDTr bioaccessibility. Comparison of in vitro and in vivo results demonstrated that DIN assay with Tenax (TI-DIN) provided the best prediction for DDTr bioavailability (r2 = 0.66, slope=0.78). After extending intestinal incubation time to 6 h or increasing bile content to 4.5 g/L (same to DIN assay) of the TI-PBET and TI-IVD assays, the in vivo-in vitro correlation will improved significantly, with r2 = 0.76 and slope= 1.4 for TI-PBET and r2 = 0.84 and slope= 1.9 for TI-IVD under 6 h intestinal incubation, and r2 = 0.59 and slope= 0.96 for TI-PBET and r2 = 0.51 and slope= 1.0 for TI-IVD under 4.5 g/L of bile content. The results suggest that it is essential to understand these key factors influencing bioaccessibility for the development of standardized in vitro methods, which helps to refine the risk assessment of human exposure to contaminants via soil ingestion.
- Published
- 2023
- Full Text
- View/download PDF
10. Human nails as a valuable noninvasive alternative for estimating exposure to parabens
- Author
-
Chao Li, Shen Xu, Dong-Xing Guan, Xian-xian Chen, and Huan He
- Subjects
Parabens and Metabolites ,Urine ,Nails ,Human exposure ,Environmental pollution ,TD172-193.5 ,Environmental sciences ,GE1-350 - Abstract
Exposure of human to parabens (commonly used preservatives) is inevitable due to their extensively applied in numerous consumer products. Thus, a reliable noninvasive matrix reflecting long-term exposure to parabens is essential for human biomonitoring study. Human nails are potentially a valuable alternative for measuring intergrated exposure to parabens. In this work, we collected 100 paired nail and urine samples from university students in Nanjing, China, and measured simultaneously for six parent parabens and four metabolites. Methylparaben (MeP), ethylparaben (EtP), and propylparaben (PrP) were three predominant paraben analogue in both matrices, with the median concentrations being 12.9, 0.753, and 3.42 ng/mL in urine, and 1540, 154, and 961 ng/g in nail, respectively, while 4-hydroxybenzoic acid (4-HB) and 3,4-dihydroxybenzoic acid (3,4-DHB) were the most abundant metabolites (median values of 143 and 35.9 ng/mL, respectively) in urine. Gender-related analysis suggested that females exposed to more higher parabens than males. Significantly positive correlations were found between levels of MeP, PrP, EtP, and OH-MeP (r = 0.54–0.62, p
- Published
- 2023
- Full Text
- View/download PDF
11. Health as a unifying concept to promote integrated soil and environmental research
- Author
-
Dong-Xing Guan, Zhou Shi, Lizhong Zhu, Yong-Guan Zhu, Randy A. Dahlgren, and Lena Q. Ma
- Subjects
Food security and safety ,Ecosystem functions and services ,Ecosystem and planetary health ,One Health and public health ,Emerging contaminants and climate change ,Sustainable development and remediation ,Environmental sciences ,GE1-350 ,Public aspects of medicine ,RA1-1270 - Published
- 2023
- Full Text
- View/download PDF
12. Environmentally relevant concentrations of arsenic induces apoptosis in the early life stage of zebrafish
- Author
-
Wen-Jun Zhao, Xiang Li, Ze-Qiong Xu, Ke-Ming Fang, Hua-Chang Hong, Hong-Jie Sun, Dong-Xing Guan, and Xin-Wei Yu
- Subjects
Environmental pollution ,TD172-193.5 ,Environmental sciences ,GE1-350 - Abstract
Arsenic (As) in the aquatic environment is a considerable environmental issue, previous studies have reported the toxic effects of low concentrations (≤ 150 μg/L) of As on fish. However, limited information is available regarding the impact of low levels of As on apoptosis. To evaluate this, zebrafish embryos were exposed to different concentrations (0, 25, 50, 75, and 150 μg/L) of As (arsenite [AsIII] and arsenate [AsV]) for 120 h. Our results indicated that low concentrations of AsIII exposure significantly inhibited the survival of zebrafish larvae, and significantly increased the transcription of Caspase-9 and Caspase-3, the ratio of Bax/Bcl-2 transcription, and protein levels of Caspase-3. In contrast, AsV decreased the ratios of Bax/Bcl-2 transcription and protein levels, as well as protein levels of Caspase-3. Our data demonstrated that AsIII and AsV exert different toxic effects, AsIII induced apoptosis via the mitochondrial pathway and the extrinsic pathway, while AsV induced apoptosis only via the mitochondrial pathway.
- Published
- 2021
- Full Text
- View/download PDF
13. Phosphorus Mobilization in Plant–Soil Environments and Inspired Strategies for Managing Phosphorus: A Review
- Author
-
Muhammad Ibrahim, Muhammad Iqbal, Yu-Ting Tang, Sardar Khan, Dong-Xing Guan, and Gang Li
- Subjects
phosphorus ,soil mobilization ,speciation ,plant uptake ,strategies ,Agriculture - Abstract
Crop productivity and yield are adversely affected by the deficiency of P in agricultural soil. Phosphate fertilizers are used at a large scale to improve crop yields globally. With the rapid increase in human population, food demands are also increasing. To see that crop yields meet demands, farmers have continuously added phosphate fertilizers to their arable fields. As the primary source of inorganic phosphorous, rock phosphate is finite and the risk of its being jeopardized in the foreseeable future is high. Therefore, there is a dire need to improve plant-available P in soil, using feasible, environmentally friendly technologies developed on the basis of further understanding of P dynamics between soil and plants. This study systemically reviews the mechanism of P uptake and P-use efficiency by plants under starvation conditions. The recent advances in various strategies, especially imaging techniques, over the period 2012–2021 for the measurement of plant-available P are identified. The study then examines how plants fulfill P requirements from tissue-stored P during P starvation. Following this understanding, various strategies for increasing plant-available P in agricultural soil are evaluated. Finally, an update on novel carriers used to improve the P content of agricultural soil is provided.
- Published
- 2022
- Full Text
- View/download PDF
14. Mechanisms of Arbuscular Mycorrhizal Fungi Increasing Silicon Uptake by Rice.
- Author
-
Li-Xue Qiu, Dong-Xing Guan, Yi-Wen Liu, Teng, H. Henry, Zi-Bo Li, Alexander Lux, Kuzyakov, Yakov, and Ma, Lena Q.
- Published
- 2024
- Full Text
- View/download PDF
15. Roles of phytohormones in mitigating abiotic stress in plants induced by metal(loid)s As, Cd, Cr, Hg, and Pb
- Author
-
Zhi-Hua Dai, Dong-Xing Guan, Jochen Bundschuh, and Lena Q. Ma
- Subjects
Environmental Engineering ,Pollution ,Waste Management and Disposal ,Water Science and Technology - Published
- 2022
16. New measures in 2022 to enhance the quality and reputation of Critical Reviews in Environmental Science and Technology journal
- Author
-
Lena Q. Ma, Dong-Xing Guan, Scott Bradford, Robert J. Letcher, Jörg Rinklebe, Yong Sik Ok, and Matthew Whittle
- Subjects
Environmental Engineering ,Pollution ,Waste Management and Disposal ,Water Science and Technology - Published
- 2022
17. Prediction of Cadmium Contents in Rice Grains from Quaternary Sediment-Distributed Farmland Using Field Investigations and Machine Learning
- Author
-
Xudong Ma, Zhongfang Yang, Tao Yu, Dong-Xing Guan, Cheng Li, Bo Li, Xu Liu, Kun Lin, Xuezhen Li, and Lei Wang
- Published
- 2023
18. Long-Range and Short-Range Structures of Multimetallic Layered Double Hydroxides
- Author
-
Wenxian Gou, Xiaoming Wang, Mengqiang Zhu, Dong-Xing Guan, Xinxin Mo, Hongtao Wang, and Wei Li
- Subjects
General Energy ,Physical and Theoretical Chemistry ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials - Published
- 2022
19. Analysis of studies on environmental measurements using diffusive gradients in thin-films (DGT) from 1994 to 2020
- Author
-
Tian-Jiao Wei, Dong-Xing Guan, Xi-Yuan Li, Yi-Long Hao, H. Henry Teng, Ji-Feng Yang, Yao-Yang Xu, and Gang Li
- Subjects
Stratigraphy ,Earth-Surface Processes - Published
- 2022
20. Qualitative and quantitative analysis for Cd2+ removal mechanisms by biochar composites from co-pyrolysis of corn straw and fly ash
- Author
-
Bingxiang Liu, Zihang Zhang, Dong-Xing Guan, Bing Wang, Shaoqi Zhou, Tong Chen, Jintao Wang, Yucheng Li, and Bo Gao
- Subjects
Environmental Engineering ,Health, Toxicology and Mutagenesis ,Public Health, Environmental and Occupational Health ,Environmental Chemistry ,General Medicine ,General Chemistry ,Pollution - Published
- 2023
21. Arsenic and selenium in the plant-soil-human ecosystem: CREST publications during 2018–2021
- Author
-
Zhi-Hua Dai, Dong-Xing Guan, Lena Q. Ma, and Hong-Jie Sun
- Subjects
Human ecosystem ,Environmental Engineering ,chemistry ,Environmental chemistry ,chemistry.chemical_element ,Environmental science ,Plant soil ,Crest ,Pollution ,Waste Management and Disposal ,Selenium ,Arsenic ,Water Science and Technology - Published
- 2021
22. Selenium Increased Arsenic Accumulation by Upregulating the Expression of Genes Responsible for Arsenic Reduction, Translocation, and Sequestration in Arsenic Hyperaccumulator
- Author
-
Zhi-Hua Dai, You-Jing Peng, Song Ding, Jia-Yi Chen, Si-Xue He, Chun-Yan Hu, Yue Cao, Dong-Xing Guan, and Lena Q. Ma
- Subjects
Arsenate Reductases ,Arsenites ,Pteris ,General Chemistry ,Selenic Acid ,Plant Roots ,Antiporters ,Arsenic ,Selenium ,Soil ,Biodegradation, Environmental ,Environmental Chemistry ,Arsenates ,Soil Pollutants - Abstract
Selenate enhances arsenic (As) accumulation in As-hyperaccumulator
- Published
- 2022
23. Nrf2/Keap1 pathway in countering arsenic-induced oxidative stress in mice after chronic exposure at environmentally-relevant concentrations
- Author
-
Hong-Jie Sun, Song Ding, Dong-Xing Guan, and Lena Q. Ma
- Subjects
Environmental Engineering ,Kelch-Like ECH-Associated Protein 1 ,NF-E2-Related Factor 2 ,Health, Toxicology and Mutagenesis ,Drinking Water ,Public Health, Environmental and Occupational Health ,General Medicine ,General Chemistry ,Pollution ,Arsenic ,Mice ,Oxidative Stress ,Environmental Chemistry ,Animals ,RNA, Messenger ,Signal Transduction - Abstract
Contamination of drinking water by carcinogen arsenic (As) is of worldwide concern as its exposure poses potential threat to human health. As such, it is important to understand the mechanisms associated with As-induced toxicity to humans. The Nrf2/Keap1 signal pathway is one of the most important defense mechanisms in cells to counter oxidative stress; however, limited information is available regarding its role in countering As-induced stress in model animal mouse. In this study, we assessed the responses of Nrf2/keap1 pathway in mice after chronic exposure to As at environmentally-relevant concentrations of 10-200 μg L
- Published
- 2022
24. Arsenic contents, speciation and bioaccessibility in rice grains from China: Regional and variety differences
- Author
-
Jia-Yi Chen, Jing-Yu Zeng, Song Ding, Jie Li, Xue Liu, Dong-Xing Guan, and Lena Q. Ma
- Subjects
China ,Environmental Engineering ,Asia ,Health, Toxicology and Mutagenesis ,Environmental Chemistry ,Humans ,Oryza ,Plant Structures ,Pollution ,Waste Management and Disposal ,Arsenic - Abstract
As the staple food for Asian countries and with its ability in arsenic accumulation, rice consumption becomes a dominant pathway for As exposure to humans. Here, we collected 108 rice samples from local markets and online sources in 13 major rice-producing regions in China, and determined As contents, speciation and bioaccessibility in the samples. Total As contents were 25-327 μg kg
- Published
- 2022
25. Uptake, speciation and detoxification of antimonate and antimonite in As-hyperaccumulator Pteris Cretica L
- Author
-
Si-Xue He, Jia-Yi Chen, Chun-Yan Hu, Ran Han, Zhi-Hua Dai, Dong-Xing Guan, and Lena Q. Ma
- Subjects
Antimony ,Biodegradation, Environmental ,Health, Toxicology and Mutagenesis ,Soil Pollutants ,Pteris ,General Medicine ,Toxicology ,Pollution ,Plant Roots ,Arsenic - Abstract
Antimony (Sb) and arsenic (As) are chemical analogs, but their behaviors in plants are different. To investigate the Sb uptake, translocation and speciation in As-hyperaccumulator P. cretica, a hydroponic experiment was conducted. In this study, P. cretica was exposed to 0.2-strength Hoagland nutrient solution, which contained 0.5 or 5 mg/L antimonite (SbIII) or antimonate (SbV). After 14 d exposure, P. cretica took up 1.4-2.8 times more SbIII than SbV. Since P. cretica was unable to translocate Sb, its roots accumulated97% Sb with the highest at 7965 mg/kg. In both SbIII and SbV treatments, SbIII was the predominant species in P. cretica, with 90-100% and 46-100% SbIII in the roots. As the first barrier against Sb to enter plant cells, more Sb was accumulated in cell wall than cytosol or organelles. The results suggest that P. cretica may detoxify Sb by reducing SbV to SbIII and immobilizing it in root cell walls. Besides, the presence of SbIII significantly reduced the concentrations of dissolved organic C including organic acids in P. cretica root exudates. Further, increasing Sb levels promoted P accumulation in the plant, especially in the fronds, which may help P. cretica growth. The information from this study shed light on metabolic transformation of Sb in As-hyperaccumulators P. cretica, which helps to better understand Sb uptake and detoxification by plants.
- Published
- 2022
26. Application of diffusive gradients in thin-films technique for speciation, bioavailability, modeling and mapping of nutrients and contaminants in soils
- Author
-
Gang Li, Lena Q. Ma, H. Henry Teng, Si-Xue He, and Dong-Xing Guan
- Subjects
Biogeochemical cycle ,Environmental Engineering ,0208 environmental biotechnology ,02 engineering and technology ,010501 environmental sciences ,Contamination ,complex mixtures ,01 natural sciences ,Pollution ,Diffusive gradients in thin films ,020801 environmental engineering ,Bioavailability ,Nutrient ,Environmental chemistry ,Genetic algorithm ,Soil water ,Environmental science ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Water Science and Technology - Abstract
Soil plays an important role in controlling the biogeochemical cycling of nutrients and contaminants in the environment. Reliable analytical techniques are critical to better understand their trans...
- Published
- 2021
27. Nickel bioaccessibility in soils with high geochemical background and anthropogenic contamination
- Author
-
Song Ding, Dong-Xing Guan, Zhi-Hua Dai, Jing Su, H. Henry Teng, Junfeng Ji, Yizhang Liu, Zhongfang Yang, and Lena Q. Ma
- Subjects
Soil ,Metals ,Nickel ,Health, Toxicology and Mutagenesis ,Soil Pollutants ,General Medicine ,Toxicology ,Environmental Pollution ,Pollution ,Environmental Monitoring - Abstract
Abnormally high concentrations of metals including nickel (Ni) in soils result from high geochemical background (HB) or anthropogenic contamination (AC). Metal bioaccessibility in AC-soils has been extensively explored, but studies in HB-soils are limited. This study examined the Ni bioaccessibility in basalt and black shale derived HB-soils, with AC-soils and soils without contamination (CT) being used for comparison. Although HB- and AC-soils had similar Ni levels (123 ± 43.0 vs 155 ± 84.7 mg kg
- Published
- 2022
28. Arsenic-Induced Up-Regulation of P Transporters Pvpht1;3-1;4 Enhances Both as and P Uptake in As-Hyperaccumulator Pteris Vittata
- Author
-
Ran Han, Jiayi Chen, Sixue He, Chunyan Hu, Zhihua Dai, Xue Liu, Dong-Xing Guan, Yue Cao, and Qiying Ma
- Subjects
History ,Polymers and Plastics ,Business and International Management ,Industrial and Manufacturing Engineering - Published
- 2022
29. Probability of Cultivating Se-Rich Maize in Se-Poor Farmland Based on Intensive Field Sampling and Artificial Neural Network Modelling
- Author
-
Xudong Ma, Zhongfang Yang, Tao Yu, and Dong-Xing Guan
- Subjects
China ,History ,Farms ,Environmental Engineering ,Polymers and Plastics ,Health, Toxicology and Mutagenesis ,Public Health, Environmental and Occupational Health ,Phosphorus ,General Medicine ,General Chemistry ,Zea mays ,Pollution ,Industrial and Manufacturing Engineering ,Selenium ,Soil ,Humans ,Soil Pollutants ,Environmental Chemistry ,Micronutrients ,Neural Networks, Computer ,Business and International Management ,Probability - Abstract
Selenium (Se) is a necessary micronutrient for humans, and its supplementation from crop grains is important to address the ubiquitous Se deficiency in people worldwide. Se uptake by crops largely depend on soil bioavailable Se rather than soil total Se content, which provides possibilities to explore the Se-rich crops in Se-poor area. Here, the possibility of cultivating Se-rich maize grains in Se-poor farmland was tested based on intensive field sampling and mathematical modelling. Sampling was conducted at county scale, and a total of 7779 topsoil samples and 109 maize samples with paired rhizosphere soils samples were collected. Results showed that although the soil Se content in the study county from southwestern China was at a low level (0.01-2.75 mg kg
- Published
- 2022
30. Improved adsorption properties of tetracycline on KOH/KMnO
- Author
-
Jin, Xu, Yin, Zhang, Bin, Li, Shisuo, Fan, Huacheng, Xu, and Dong-Xing, Guan
- Subjects
Kinetics ,Heterocyclic Compounds ,Charcoal ,Adsorption ,Tetracycline ,Triticum ,Water Pollutants, Chemical ,Anti-Bacterial Agents - Abstract
Modification of pristine biochars has received increasing attentions due to the significant potential in enhancing adsorption performance. In this work, the co-modification of KOH and KMnO
- Published
- 2021
31. Transferability of heavy metal(loid)s from karstic soils with high geochemical background to peanut seeds
- Author
-
Qiong Yang, Zhongfang Yang, Qizuan Zhang, Wenbing Ji, Dong-Xing Guan, Xu Liu, Tao Yu, Lei Wang, Xiaoxiong Zhuo, and Junfeng Ji
- Subjects
China ,Soil ,Arachis ,Health, Toxicology and Mutagenesis ,Metals, Heavy ,Soil Pollutants ,General Medicine ,Toxicology ,Pollution ,Risk Assessment ,Environmental Monitoring - Abstract
Globally distributed karstic soils are characterized by the high accumulation of heavy metal(loid)s, such as Cd. Biogeochemistries and transferability of metal(loid)s in such soils are notably different from that in soils of anthropogenic pollution as evidenced by increasing studies about rice and maize. To solve the question about metal(loid) background and transferability in the system of karstic soils and crops with underground fruits, we designedly collected 246 paired soil-peanut seed samples in a world-famous karstic region in Southwestern China covering an area of 98,700 km
- Published
- 2021
32. Amine- and thiol-bifunctionalized mesoporous silica material for immobilization of Pb and Cd: Characterization, efficiency, and mechanism
- Author
-
Xue Liu, Jing-Wei Fu, Lena Q. Ma, Shi Xinyao, Ni Tang, Meng-Ru Jia, and Dong-Xing Guan
- Subjects
Environmental Engineering ,Sorbent ,Chemistry ,Health, Toxicology and Mutagenesis ,Public Health, Environmental and Occupational Health ,Sorption ,General Medicine ,General Chemistry ,Mesoporous silica ,Silicon Dioxide ,Pollution ,Chemical reaction ,X-ray photoelectron spectroscopy ,Lead ,Environmental Chemistry ,Amine gas treating ,Adsorption ,Sulfhydryl Compounds ,Fourier transform infrared spectroscopy ,Amines ,Mesoporous material ,Nuclear chemistry ,Cadmium - Abstract
In this study, a two-step functionalizing strategy by combining co-condensation with grafting procedures was employed to synthesize well-ordered Amino- and Thiol-Bifunctionalized SBA-15 (ATBS) mesoporous silica. Its physicochemical properties, performance, and mechanisms in immobilization of toxic metals Pb and Cd in water and soil were investigated. After bi-functionalization, X-ray diffractometer, transmission electron microscope, and N2 adsorption-desorption measurements confirmed that the ATBS maintained a highly-ordered mesoporous structure, large surface area and pore volume. The elemental analysis, Fourier transform infrared spectroscopy and X-ray Photoelectron Spectroscopy (XPS) evidenced the successful incorporation of amine and thiol groups into ATBS. These structure and functional characteristics of ATBS benefited Pb and Cd sorption. Sorption isotherms of Pb and Cd were better fit with Sips and Redlich-Peterson models. Sorption kinetics suggested that Pb sorption was mainly regulated by chemical reactions, whereas both diffusion process and chemical reactions were rate-regulating steps in Cd sorption. ATBS showed the maximum sorption capacities for Pb and Cd at 120 and 38 mg g-1, respectively. The sorption mechanisms revealed by XPS measurements suggested that Cd sorption was mainly attributed to thiol groups while Pb was efficiently bond to both thiol and amino groups. High and stable sorption efficiencies were attained in the pH range of 4-6, with a higher affinity towards Pb than Cd. Furthermore, its ability to immobilize Pb and Cd in soils was examined with an incubation experiment, which showed that ATBS reduced 30-56% of MgCl2-extractable Pb and Cd in a contaminated soil. The synthesized sorbent via the two-step functionalizing strategy shows high sorption efficiency towards Pb and Cd, and thus it has potential application in remediating Pb and Cd contaminated water and soils.
- Published
- 2021
33. Selenate increased plant growth and arsenic uptake in As-hyperaccumulator Pteris vittata via glutathione-enhanced arsenic reduction and translocation
- Author
-
Yue Cao, Xue Liu, Ran Han, Shuxin Tu, Song Ding, Zhihua Dai, Dong-Xing Guan, Jia-Yi Chen, and Lena Q. Ma
- Subjects
Environmental Engineering ,Health, Toxicology and Mutagenesis ,Glutathione reductase ,chemistry.chemical_element ,Selenic Acid ,Selenate ,Plant Roots ,Arsenic ,chemistry.chemical_compound ,Botany ,Environmental Chemistry ,Soil Pollutants ,Hyperaccumulator ,Waste Management and Disposal ,chemistry.chemical_classification ,biology ,Glutathione peroxidase ,Arsenate ,Pteris ,Glutathione ,biology.organism_classification ,Pollution ,Biodegradation, Environmental ,chemistry ,Pteris vittata ,Selenium - Abstract
The beneficial effects of selenium on As uptake and plant growth in As-hyperaccumulator Pteris vittata are known, but the associated mechanisms remain unclear. Here, we investigated the effects of selenate on arsenic accumulation by P. vittata under two arsenate levels. P. vittata plants were exposed to 13 (As13) or 133 µM (As133) arsenate and 5 µM selenate in 0.2-strength Hoagland solution. After 14 d of growth, plant biomass, Se and As content, As speciation, and malondialdehyde (MDA), glutathione reductase (GR), glutathione peroxidase (GPX), and glutathione (GSH and GSSG) levels were determined. The results show that selenate promoted P. vittata growth and increased As concentrations in the roots and fronds by 256% from 97 to 346 mg kg−1 and 142% from 213 to 514 mg kg−1 under As13 treatment, and by 166% from 500 to 1332 mg kg−1 and 534% from 777 to 4928 mg kg−1 under As133 treatment. In addition, selenate increased the glutathione content in P. vittata roots and fronds by 75–86% under As13 treatment and 44–45% under As133 treatment. Selenate also increased the GPX activity by 161–173%, and GR activity by 72–79% in P. vittata under As13 and As133 treatments. The HPLC-ICP-MS analysis indicated that selenate increased both AsIII and AsV levels in P. vittata, with AsIII/AsV ratio being lower in the roots and higher in the fronds, i.e., more AsIII was being translocated to the fronds. Taken together, our results suggest that, via GPX-GR mediated enhancement of GSH-GSSG cycle, selenate effectively increases plant growth and As uptake in P. vittata by improving AsV reduction in the roots and AsIII translocation from the roots to the fronds.
- Published
- 2021
34. Arsenic and selenium in the plant-soil-human ecosystem: CREST publications during 2018-2021.
- Author
-
Dong-Xing Guan, Zhi-Hua Dai, Hong-Jie Sun, and Ma, Lena Q.
- Subjects
- *
ENVIRONMENTAL sciences , *TOXICOLOGICAL interactions , *HEAVY metals , *SOIL remediation , *ARSENIC , *ECOSYSTEMS , *SELENIUM , *PLANT-soil relationships - Abstract
The biogeochemical transformations and biological effects of metalloids arsenic (As) and selenium (Se) in the environment has been extensively explored during the last decade, mainly owing to their ubiquitous distribution in the environment and their toxicity to biota. Here, we summarized recent research progress regarding As and Se in plant-soil-human ecosystem based on 17 publications in Critical Reviews in Environmental Science and Technology (CREST) during 2018-2021. The topics include: 1) organic As transformation in the environment and inorganic As uptake by plants (4 publications), 2) Se uptake by plants and its interactions with toxic metals in plants (6 publications), 3) As bioaccessibility and remediation of As-contaminated soils (4 publications), and 4) As research across spatial and temporal scale (3 publications). Specifically, the uptake, transformation, toxicity, bioaccessibility of As/Se in the plant-soil-human ecosystem together with pollution control measures are summarized. Future studies should focus on better understanding the cycling and biogeochemistry of As/Se in the environment, further decoding their environmental effects from the One Health perspective. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
35. Assessment of DDT and its Metabolites Bioaccessibility in Historically Contaminated Soils Using Unfed and Fed in Vitro Methods
- Author
-
Chao Li, Shen Xu, Dong-xing Guan, Xian-xian Chen, and Huan He
- Subjects
Soil ,Health, Toxicology and Mutagenesis ,Biological Availability ,Humans ,Soil Pollutants ,General Medicine ,Toxicology ,Pollution ,DDT ,Environmental Monitoring - Abstract
Bioaccessibility of hydrophobic organic contaminants (HOCs) from unintentional ingestion of soil is increasingly assessed with in vitro gastrointestinal models incorporating a sorption sink. In this study, the bioaccessibility of DDTs in contaminated soils (n = 11) was determined using "unfed" unified bioaccessibility method (UBM) and fed organic estimation human simulation test (FOREhST) with/without Tenax as an absorbent. By adding Tenax, the bioaccessibility of DDTs determined using UBM was significantly increased from 4.9-30.6% to 31.6-86.0%. In contrast, the bioaccessibility of DDTs determined using FOREhST without/with Tenax were similar with values of 20.0-60.9% vs 31.5-47.6%, implying that the influence of food components on the absorption efficiency of the sink should not be overlooked. Much high fraction of DDTs (bioaccessibility: 11.7-24.8%) remained in FOREhST supernatant after Tenax collection, suggesting that prediction of bioavailability through bioaccessibility obtained by absorbent needs to be treated with caution when bioaccessibility is determined using a "fed state" in vitro method.
- Published
- 2021
36. Geographical distribution of As-hyperaccumulator Pteris vittata in China: Environmental factors and climate changes
- Author
-
Shuang Yan, Wumei Xu, Yue Cao, Dong-Xing Guan, Lena Q. Ma, Qinglian Du, and Xue Liu
- Subjects
China ,Environmental Engineering ,biology ,Range (biology) ,business.industry ,Ecology ,Climate Change ,Species distribution ,Climate change ,Distribution (economics) ,Pteris ,biology.organism_classification ,Pollution ,Arsenic ,Phytoremediation ,Biodegradation, Environmental ,Pteris vittata ,Environmental Chemistry ,Environmental science ,Soil Pollutants ,Hyperaccumulator ,Precipitation ,business ,Waste Management and Disposal - Abstract
Understanding the distribution of hyperaccumulators helps to implement more efficient phytoremediation strategies of contaminated sites, however, limited information is available. Here, we investigated the geographical distribution of the first-known arsenic-hyperaccumulator Pteris vittata in China and the key factors under two climate change scenarios (SSP 1-2.6 and SSP 5-8.5) at two time points (2030 and 2070). Species distribution model (MaxEnt) was applied to examine P. vittata distribution based on 399 samples from field surveys and existing specimen records. Further, among 23 environmental factors, 11 variables were used in the MaxEnt model, including temperature, precipitation, elevation, soil property, and UV-B radiation. The results show that P. vittata can grow in ~23% of the regions in China. Specifically, it is mainly distributed in 11 provinces of southern China, including Hainan, Guangdong, Guangxi, Yunnan, Guizhou, Hunan, Hubei, Jiangxi, Fujian, Zhejiang, and Jiangsu. Besides, eastern Sichuan, and southern Henan, Shaanxi, and Anhui are suitable for P. vittata growth. Under two climate change scenarios, P. vittata distribution in China would decrease by ~5.76-7.46 × 104 km2 in 2030 and ~3.22-4.68 × 104 km2 in 2070, with southern Henan and most Jiangsu being unsuitable for P. vittata growth. Among the 11 environmental variables, the minimum temperature of coldest month (bio6) and temperature annual range (bio7) are the two key factors limiting P. vittata distribution. At bio6 33 °C, the regions are unsuitable for P. vittata growth. Based on the MaxEnt model, precipitation had limited effects, so P. vittata can probably survive under both dry and moist environments. This study helps guide phytoremediation of As-polluted soils using P. vittata and provides an example to evaluate habitat suitability of hyperaccumulators at international scales.
- Published
- 2021
37. Decomplexation of Cr(III)-EDTA and simultaneous abatement of total Cr by photo-oxidation: efficiency and in situ reduction of intermediate Cr(VI)
- Author
-
Zhao Min, Bei Ke, Qi Wang, Jin Zhan, Dong-Xing Guan, Zhang Yejian, Xiangyong Zheng, Huabin Zhou, Huang Xianfeng, and Xiran Wang
- Subjects
Chromium ,Ultraviolet Rays ,Decarboxylation ,Health, Toxicology and Mutagenesis ,Radical ,chemistry.chemical_element ,Wastewater ,010501 environmental sciences ,01 natural sciences ,Mineralization (biology) ,Spectroscopy, Fourier Transform Infrared ,Environmental Chemistry ,Irradiation ,Effluent ,Edetic Acid ,0105 earth and related environmental sciences ,Chemistry ,Advanced oxidation process ,General Medicine ,Photochemical Processes ,Electroplating ,Pollution ,Models, Chemical ,Degradation (geology) ,Oxidation-Reduction ,Water Pollutants, Chemical ,Nuclear chemistry - Abstract
Most prevailing processes are incapable of removing Cr(III)-organic complexes efficiently and facing the problem of in-process formation of highly toxic Cr(VI) based on oxidation. The efficient decomplexation of Cr(III) complexes and simultaneous abatement of Cr with low Cr(VI) accumulation would be desirable in treatment of Cr(III)-complexed wastewater. Here, we found efficient degradation of Cr(III)-EDTA and simultaneous removal of Cr by forming Cr2O3 precipitate from simulated solution as well as an electroplating effluent under UV irradiation. The results showed a complete degradation of Cr(III)-EDTA after reaction time of 60 min and 70–80% of TOC mineralization within 180 min as well. About 90% of Cr(III) precipitated as Cr2O3 simultaneously, with the residual total Cr below 1.5 mg/L. The degradation of Cr(III)-EDTA was a stepwise de-acetate group process, as proven by the obvious attenuation of peaks related to carboxyl groups and C–C bond from FT-IR spectra of Cr(III)-EDTA and significant mineralization of TOC after UV irradiation. Based on negligible accumulation of Cr(VI) (less than 0.1 mg/L) under N2-sparged condition, the C-centered radicals from the β-fragmentation of O-centered radicals formed by photo-induced ligand-to-metal charge transfer were responsible for the in situ reduction of intermediate Cr(VI), resulting in the low accumulation of Cr(VI). The addition of 20 mg/L Fe2+ was capable of removing the remaining Cr(VI) and total Cr, with Cr(VI) and total Cr less than 0.1 and 1.0 mg/L, respectively. Moreover, the photo-oxidation process combined with Fe2+ addition were efficient in removing other Cr(III) complexes, such as Cr(III)-citrate and those from a realistic electroplating effluent. We believe that this study would provide an alternative option for efficient degradation of Cr(III) complexes and simultaneous abatement of Cr from contaminated water.
- Published
- 2019
38. Improved adsorption properties of tetracycline on KOH/KMnO4 modified biochar derived from wheat straw
- Author
-
Jin Xu, Yin Zhang, Bin Li, Shisuo Fan, Huacheng Xu, and Dong-Xing Guan
- Subjects
Environmental Engineering ,Health, Toxicology and Mutagenesis ,Public Health, Environmental and Occupational Health ,Environmental Chemistry ,General Medicine ,General Chemistry ,Pollution - Published
- 2022
39. Correlative distribution of DOM and heavy metals in the soils of the Zhangxi watershed in Ningbo city, East of China
- Author
-
Zhe Wang, Ruixia Han, Azeem Muhammad, Dong-Xing Guan, Eric Zama, and Gang Li
- Subjects
China ,Soil ,Spectrometry, Fluorescence ,Metals, Heavy ,Health, Toxicology and Mutagenesis ,General Medicine ,Dissolved Organic Matter ,Toxicology ,Pollution ,Ecosystem ,Humic Substances - Abstract
In peri-urban critical zones, soil ecosystems are highly affected by increasing urbanization, causing probably an intense interaction between dissolved organic matter (DOM) and heavy metals in soil. Such interaction is critical for understanding the biogeochemical cycles of both organic matter and heavy metals in these zones. However, limited research has reported the correlative distribution of DOM and heavy metals at high seasonal and spatial resolutions in peri-urban critical zones. In this study, 160 soil samples were collected from the farmland and forestland of Zhangxi watershed, in Ningbo, eastern China during spring, summer, fall and winter four seasons. UV-visible absorption and fluorescent spectroscopy were used to explore the optical characteristics of DOM. The results indicated a mixture of exogenous and autogenous sources of DOM in the Zhangxi watershed, while DOM in farmland exhibited a higher degree of aromaticity and humification than that in forestland. Fluorescent results showed that humic acid-like, fulvic acid-like and microbial-derived humic-like fractions were mostly affected by seasons. The distribution of heavy metals was affected mainly by land-use changes and seasons. Correlation analysis between heavy metals and DOM characteristics and components suggested that aromatic and humic substances were more favorable in binding with EDTA extractable Ni, Cu, Zn and Cd. The bioavailable Cd and Pb decreased due to binding with humic fractions, indicating its great effects on the bioavailability of Cd and Pb. Overall, these findings provide an insight into the correlative distributions of DOM and heavy metals in peri-urban areas, thereby highlighting their biogeochemical cycling in the soil environment.
- Published
- 2022
40. Correlative Distribution of DOM and Heavy Metals in the Soils of a Typical Peri-Urban Critical Zone
- Author
-
Azeem Muhammad, Gang Li, Zhe Wang, Ruixia Han, Eric Fru Zama, and Dong-Xing Guan
- Subjects
chemistry.chemical_classification ,History ,Biogeochemical cycle ,Watershed ,Polymers and Plastics ,Soil test ,complex mixtures ,Industrial and Manufacturing Engineering ,Humus ,chemistry ,Environmental chemistry ,Soil water ,Dissolved organic carbon ,Environmental science ,Organic matter ,Ecosystem ,Business and International Management - Abstract
In peri-urban critical zones, soil ecosystems are highly affected by increasing urbanization, causing probably an intense interaction between dissolved organic matter (DOM) and heavy metals in soil. Such interaction is critical for understanding the biogeochemical cycles of both organic matter and heavy metals in these zones. However, limited research has reported the correlative distribution of DOM and heavy metals at high seasonal and spatial resolutions in peri-urban critical zones. In this study, 160 soil samples were collected from the farmland and forestland of Zhangxi watershed, in Ningbo, eastern China during spring, summer, fall and winter four seasons. UV-visible absorption and fluorescent spectroscopy were used to explore the optical characteristics of DOM. The results indicated a mixture of exogenous and autogenous sources of DOM in the Zhangxi watershed, while DOM in farmland exhibited a higher degree of aromaticity and humification than that in forestland. Fluorescent results showed that humic acid-like, fulvic acid-like and microbial-derived humic-like fractions were mostly affected by seasons. The distribution of heavy metals was affected mainly by land-use changes and seasons. Correlation analysis between heavy metals and DOM characteristics and components suggested that aromatic and humic substances were more favorable in binding with EDTA extractable Ni, Cu, Zn and Cd. The bioavailable Cd and Pb decreased due to binding with humic fractions, indicating that DOM had great effects on the heavy metal bioavailability. Overall, these findings provide an insight into the correlative distributions of DOM and heavy metals in peri-urban areas, thereby highlighting their biogeochemical cycling in the soil environment.
- Published
- 2021
41. Localized intensification of arsenic release within the emergent rice rhizosphere
- Author
-
Yue Gao, Hao Zhang, Dong-Xing Guan, Jun Luo, Fang-Jie Zhao, Daixia Yin, Lena Q. Ma, Wen Fang, Eduardo Moreno-Jiménez, Paul N. Williams, UAM. Departamento de Química Agrícola, Chemistry, and Analytical, Environmental & Geo-Chemistry
- Subjects
chemistry.chemical_element ,010501 environmental sciences ,Spatial distribution ,01 natural sciences ,Oxygen ,Arsenic ,Soil ,Nutrient ,Flux (metallurgy) ,Soil Pollutants ,Environmental Chemistry ,0105 earth and related environmental sciences ,Rhizosphere ,Phosphorus ,Oryza ,General Chemistry ,Transition metals ,Química ,Elements ,Medio Ambiente ,chemistry ,Fluxes ,Environmental chemistry ,Soil water ,Soils ,Plant derived food - Abstract
This document is the Accepted Manuscript version of a Published Work that appeared in final form in Environmental Science & Technology, © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see: https://pubs.acs.org/doi/full/10.1021/acs.est.9b04819, Behavior of trace elements in flooded/lowland rice soils is controlled by root-zone iron oxidation. Insoluble iron species bind/capture toxic elements, i.e., arsenic. However, it was recently observed that within this territory of arsenic immobilization lies a zone of prolific iron release, accompanied by a significant flux of arsenic in close proximity to rice root apices. Questions still remain on how common this phenomenon is and whether the chemical imaging approaches or soils/cultivars used influence this event. Here, three types of ultrathin/high-resolution diffusive gradient in thin films (DGT) substrates were integrated with oxygen planar optodes in a multilayer system, providing two-dimensional mapping of solute fluxes. The three DGT approaches revealed a consistent/overlapping spatial distribution with localized flux maxima for arsenic, which occurred in all experiments, concomitant with iron mobilization. Soil/porewater microsampling within the rhizosphere revealed no significant elevation in the solid phase’s total iron and arsenic concentrations between aerobic and anaerobic zones. Contrary to arsenic, phosphorus bioavailability was shown to decrease in the arsenic/iron flux maxima. Rice roots, in addition to their role in nutrient acquisition, also perform a key sensory function. Flux maxima represent a significant departure from the chemical conditions of the bulk/field environment, but our observations of a complete rhizosphere reveal a mixed mode of root–soil interactions, This work was funded by the National Natural Science Foundation of China (No. 41771271), the Fundamental Research Funds for the Central Universities (021114380126), the National Natural Science Foundation of China (No. 41807023), and the Jiangsu Province Natural Science Foundation (BK20180344). The study also received support from the Newton Fund/Royal Society and NFSC (R1504GFS and 21511130063)
- Published
- 2020
42. Antioxidant responses and pathological changes in the gill of zebrafish (Danio rerio) after chronic exposure to arsenite at its reference dose
- Author
-
Shui-Ping Shu, Hong-Jie Sun, Huachang Hong, Dong-Xing Guan, Wen-Jun Zhao, Xiao-Qiang Teng, and Shi-Wei Li
- Subjects
Gills ,animal structures ,Antioxidant ,Arsenites ,Health, Toxicology and Mutagenesis ,medicine.medical_treatment ,0211 other engineering and technologies ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Antioxidants ,Andrology ,Superoxide dismutase ,chemistry.chemical_compound ,Malondialdehyde ,medicine ,Animals ,RNA, Messenger ,Zebrafish ,0105 earth and related environmental sciences ,Arsenite ,021110 strategic, defence & security studies ,biology ,Superoxide Dismutase ,fungi ,Public Health, Environmental and Occupational Health ,General Medicine ,biology.organism_classification ,Catalase ,Pollution ,Mucus ,Oxidative Stress ,chemistry ,biology.protein ,Water Pollutants, Chemical ,Fish gill - Abstract
Gill, as the organ of fish to contact most directly with xenobiotics, suffered more threat. To evaluate the impact of arsenite (AsIII) on the gill of fish, we measured the antioxidative responses (superoxide dismutase (SOD) and catalase (CAT) activities) and oxidative damage (malondialdehyde (MDA) content), histological changes and mRNA transcriptional responses of zebrafish gill, after exposure to AsIII (0, 10, 50, 100, and 150 μg L−1) solutions for 28 days. We found that AsIII increased the activities of CAT by 46%–87%, decreased the activities of SOD and the contents of MDA by 19% and 21%–32%. Furthermore, CuZnSOD and MnSOD mRNA transcription levels were also inhibited, decreasing by 62%–82% and 70%–77%. Besides, ≥ 100 μg L−1 AsIII also caused histological changes (a loss of mucus and desquamation in the surface of the epithelial cells) on zebrafish gill. These results showed that low concentrations of AsIII influenced biochemical and physiological performances of fish gill, which probably aggravates the toxic effect of AsIII on fish.
- Published
- 2020
43. Total and available metal concentrations in soils from six long-term fertilization sites across China
- Author
-
Guanghui Yu, Fu-Sheng Sun, Yun-Gen Liu, Dong-Xing Guan, and Matthew L. Polizzotto
- Subjects
Crops, Agricultural ,China ,Nitrogen ,Health, Toxicology and Mutagenesis ,chemistry.chemical_element ,010501 environmental sciences ,01 natural sciences ,Soil ,Human fertilization ,Metals, Heavy ,Soil pH ,Animals ,Soil Pollutants ,Environmental Chemistry ,Fertilizers ,0105 earth and related environmental sciences ,Cadmium ,Phosphorus ,Agriculture ,04 agricultural and veterinary sciences ,General Medicine ,Pollution ,Diffusive gradients in thin films ,Soil contamination ,Manure ,Zinc ,chemistry ,Environmental chemistry ,Soil water ,Potassium ,040103 agronomy & agriculture ,0401 agriculture, forestry, and fisheries ,Environmental Pollution ,Copper ,Environmental Monitoring - Abstract
Approximately 19% of agricultural soils in China are contaminated by heavy metals. However, the effects of agricultural management practices on soil contamination are not well understood. Taking advantage of six long-term (23-34 years) field sites across China, this study examined the effects of different agricultural fertilization treatments, including control (no fertilization), inorganic nitrogen, phosphorus and potassium fertilization (NPK), manure fertilization (M), and NPK plus manure fertilization (NPKM), on the total and available metal concentrations in soils. The results showed that after 23-34 years of fertilization, the M and NPKM treatments significantly increased the total concentration of cadmium (Cd), copper (Cu), and zinc (Zn) in soils compared with the concentrations measured for the control and NPK treatments. In contrast, the fertilization treatments had almost no influence on soil lead (Pb) and nickel (Ni) concentrations. The results of analysis via diffusive gradients in thin films demonstrated that long-term sheep or cattle manure fertilization increased the available metals, especially Cd, Cu, and Zn, but long-term swine manure application decreased the available metals, except for Cu and Zn, in soils. Further analysis revealed that the manure source, soil pH level, and biogeochemical properties of metals affected the availability of Cd, Cu, Pb, Zn, and Ni in soils. Collectively, organic fertilizers had the potential to reduce metal uptake by crops, but caution should be taken to reduce metal concentrations in manure.
- Published
- 2018
44. Comparing CaCl
- Author
-
Qiang, Ma, Wanfu, Zhao, Dong-Xing, Guan, H Henry, Teng, Junfeng, Ji, and Lena Q, Ma
- Subjects
China ,Soil ,Nickel ,Metals, Heavy ,Biological Availability ,Soil Pollutants ,Oryza ,Edetic Acid ,Cadmium - Abstract
Urbanization and industrialization have elevated metal concentrations in soils. However, systematic investigation on their availability in regional soils under industrial impacts is lacking. In this study, 230 paired soil-rice samples were collected from two areas in Southeast China, with low and high industrial impacts. Classic equilibrium-based CaCl
- Published
- 2019
45. DGT technique to assess P mobilization from greenhouse vegetable soils in China: A novel approach
- Author
-
Yusef Kianpoor Kalkhajeh, Helle Sørensen, Peter E. Holm, Hans Christian Bruun Hansen, Biao Huang, Jun Luo, Dong-Xing Guan, and Wenyou Hu
- Subjects
Topsoil ,Environmental Engineering ,Chemistry ,Greenhouse ,Soil classification ,04 agricultural and veterinary sciences ,010501 environmental sciences ,Soil type ,01 natural sciences ,Pollution ,Environmental chemistry ,Soil water ,040103 agronomy & agriculture ,0401 agriculture, forestry, and fisheries ,Environmental Chemistry ,Soil properties ,Leaching (agriculture) ,Eutrophication ,Waste Management and Disposal ,0105 earth and related environmental sciences - Abstract
Intensive phosphorus (P) inputs to plastic-covered greenhouse vegetable production (PGVP) in China has led to excessive soil P accumulation increasing the potential for leaching to surface waters. This study examined the mobility and hence the potential risk of P losses through correlations between soil solution P (PSol) and soil extractable P as determined by conventional soil P test methods (STPs) including degree of P saturations (DPSs), and diffusive gradient in thin-films (DGT P) technique. A total of 75 topsoil samples were chosen from five representative Chinese PGVPs covering a wide range of physiochemical soil properties and cultivation history. Total P and Olsen P contents varied from 260 to 4900, and 5 to 740mgkg-1, respectively, while PSol concentrations were between 0.01 and 10.8mgL-1 reflecting the large differences in vegetation history, fertilization schemes, and soil types. Overall, DGT P provided the best correlation with PSol (r2=0.97) demonstrating that DGT P is a versatile measure of P mobility regardless of soil type. Among the DPSs tested, oxalate extractable Al (DPSOx-Al) had the best correlation with PSol (r2=0.87). In the STP versus PSol relationships, STP break-points above which P mobilization increases steeply were 513μgL-1 and 190mgkg-1 for DGT P or Olsen P, respectively, corresponding to PSol concentration of 0.88mgL-1. However, for PSol concentration of 0.1mgL-1 that initiates eutrophication, the corresponding DGT P and Olsen P values were 27μgL-1 and 22mgkg-1, respectively. Over 80% of the investigated soils had DGT P and Olsen P above these values, and thus are at risk of P mobilization threatening receiving waters by eutrophication. This paper demonstrates that the DGT extracted P is a powerful measure for soluble P and hence for assessment of P mobility from a broad range of soil types.
- Published
- 2018
46. Characterization of Lead Uptake by Nano-Sized Hydroxyapatite: A Molecular Scale Perspective
- Author
-
Chao Ren, Dong-Xing Guan, Wei Li, Zongqiang Zhu, Yinian Zhu, and Jingzhao Wang
- Subjects
Atmospheric Science ,Chemistry ,Precipitation (chemistry) ,010501 environmental sciences ,010502 geochemistry & geophysics ,Soil remediation ,01 natural sciences ,Characterization (materials science) ,Adsorption ,Space and Planetary Science ,Geochemistry and Petrology ,Transmission electron microscopy ,Nano sized ,High-resolution transmission electron microscopy ,0105 earth and related environmental sciences ,Nuclear chemistry ,Solid solution - Abstract
Sequestration of toxic metals (e.g., Pb) by hydroxyapatite (HAP) has attracted wide attention in soil remediation. In this study, a comprehensive investigation on Pb uptake by HAP was conducted using combined batch method, X-ray diffraction (XRD), Fourier-transform infrared, and high-resolution transmission electron microscopy (HRTEM). Results revealed that the Pb uptake mechanism involves not only surface adsorption and precipitation but also incorporation depending on the initial Pb concentration. At low Pb concentrations (e.g., 0.1 mM), surface adsorption may contribute considerably to the total Pb uptake as no changes were observed in the XRD analysis. At medium concentrations of 0.5–5.7 mM, formation of lead phosphate precipitates was evidenced by XRD analysis with new peaks at 2θ of ∼30.3° and can be indexed to crystalline hydroxypyromorphite (HPY). This was also consistent with the ratios (0.9–1.0) of Pbsorbed/Cadissolved at Pb level of 2.5–5.7 mM. At higher Pb concentrations (≥6.6 mM), larger rati...
- Published
- 2018
47. Environmentally relevant concentrations of arsenic induces apoptosis in the early life stage of zebrafish
- Author
-
Xin-Wei Yu, Xiang Li, Wen-Jun Zhao, Hong-Jie Sun, Dong-Xing Guan, Zeqiong Xu, Ke-Ming Fang, and Huachang Hong
- Subjects
animal structures ,Health, Toxicology and Mutagenesis ,Mitochondrial pathway ,chemistry.chemical_element ,Apoptosis ,Environmental pollution ,Arsenic ,chemistry.chemical_compound ,Transcription (biology) ,Zebrafish larvae ,Animals ,GE1-350 ,Zebrafish ,biology ,Public Health, Environmental and Occupational Health ,Arsenate ,General Medicine ,biology.organism_classification ,Pollution ,Molecular biology ,Early life ,Environmental sciences ,TD172-193.5 ,chemistry ,Larva ,embryonic structures ,Arsenates - Abstract
Arsenic (As) in the aquatic environment is a considerable environmental issue, previous studies have reported the toxic effects of low concentrations (≤ 150 μg/L) of As on fish. However, limited information is available regarding the impact of low levels of As on apoptosis. To evaluate this, zebrafish embryos were exposed to different concentrations (0, 25, 50, 75, and 150 μg/L) of As (arsenite [AsIII] and arsenate [AsV]) for 120 h. Our results indicated that low concentrations of AsIII exposure significantly inhibited the survival of zebrafish larvae, and significantly increased the transcription of Caspase-9 and Caspase-3, the ratio of Bax/Bcl-2 transcription, and protein levels of Caspase-3. In contrast, AsV decreased the ratios of Bax/Bcl-2 transcription and protein levels, as well as protein levels of Caspase-3. Our data demonstrated that AsIII and AsV exert different toxic effects, AsIII induced apoptosis via the mitochondrial pathway and the extrinsic pathway, while AsV induced apoptosis only via the mitochondrial pathway.
- Published
- 2021
48. Effect of phosphate minerals on phytoremediation of arsenic contaminated groundwater using an arsenic-hyperaccumulator
- Author
-
Jorge A.G. Santos, Guang-Mei Yang, Yanshan Chen, Dong-Xing Guan, Gang Li, and Ling-Jia Zhu
- Subjects
021110 strategic, defence & security studies ,integumentary system ,biology ,Chemistry ,Ammonium phosphate ,Phosphorus ,0211 other engineering and technologies ,Environmental engineering ,Soil Science ,chemistry.chemical_element ,02 engineering and technology ,Plant Science ,010501 environmental sciences ,biology.organism_classification ,Phosphate ,01 natural sciences ,Phytoremediation ,chemistry.chemical_compound ,Phosphorite ,Environmental chemistry ,Pteris vittata ,Arsenic ,0105 earth and related environmental sciences ,General Environmental Science ,Hoagland solution - Abstract
To investigate the effect of phosphate sources on phytoremediation of arsenic (As) contaminated groundwater using Pteris vittata, a hydroponic experiment was conducted. Sparingly-soluble phosphate minerals (phosphate rock, PR, and hydroxyapatite, HA) and soluble Hoagland solution (HS, containing ammonium phosphate) were chosen as phosphate sources. Arsenic content in the residual nutrient solutions was analyzed to acquire the phytoextraction effect. The results showed that As concentrations in the nutrient solutions treated with sparingly-soluble P decreased more rapidly than that treated with soluble P. For treatment with sparingly-soluble PR, P. vittata reduced As concentration more rapidly than that in HA treatment and HS control. Nitrate and P concentrations in the residual solutions were also monitored to check eutrophication pollution. Phosphorus in the residual solutions in PR or HA treatment was not detected and 0.5 μ g L−1, respectively, much lower than HS control. These results indicated that sparingly-soluble PR could be an ideal P source to facilitate As removal from contaminated groundwater by P. vittata and ensure the nutrient quality of the residual water after phytoremediation.
- Published
- 2017
49. A diffusive gradients in thin-films technique for the assessment of bisphenols desorption from soils
- Author
-
William Davison, Dong-Xing Guan, Hao Zhang, Jun Luo, Jian-Lun Zheng, and Lena Q. Ma
- Subjects
Environmental Engineering ,010504 meteorology & atmospheric sciences ,Chemistry ,Health, Toxicology and Mutagenesis ,Kinetics ,Analytical chemistry ,010501 environmental sciences ,01 natural sciences ,Pollution ,Diffusive gradients in thin films ,Solution phase ,Partition coefficient ,Adsorption ,Environmental chemistry ,Desorption ,Soil water ,Environmental Chemistry ,Partition (number theory) ,Waste Management and Disposal ,0105 earth and related environmental sciences - Abstract
Desorption/adsorption of bisphenols (BPs) in soils affects their mobility and availability. However, the kinetics of these processes have not been well studied, due to the lack of appropriate means of measurement. Diffusive gradients in thin-films (DGT) technique can assess kinetic processes in soils and have recently been developed for measuring three BPs (BPA, BPB and BPF). DGT was deployed for 2.5 h to 20 d in five soils with different soil properties. Non-linear increase in mass accumulation by DGT with time indicated poor resupply of BPs from soil solid to solution phase. By fitting the data with DIFS (DGT-induced fluxes in soils) model, values for the labile partition coefficient (Kdl), response time (tc) and rates of exchange (k1 and k-1) of BPs between soil solid and solution phases were obtained. The derived values of Kdl showed that most of the BPs in the soil could participate in labile exchange. Average response times of 1–2 h implied that the supply of BPs to DGT was limited by their desorption rate. Soils with more binding sites (higher DOM, CEC and Fe oxides) could resupply BPs more quickly, highlighting the danger of just considering partition effects.
- Published
- 2017
50. Exploring the interactions and binding sites between Cd and functional groups in soil using two-dimensional correlation spectroscopy and synchrotron radiation based spectromicroscopies
- Author
-
Fu-Sheng Sun, Qirong Shen, Dong-Xing Guan, Matthew L. Polizzotto, Jun Wu, Boren Wang, Wei Ran, and Guanghui Yu
- Subjects
Cadmium ,Environmental Engineering ,010504 meteorology & atmospheric sciences ,Health, Toxicology and Mutagenesis ,Synchrotron radiation ,chemistry.chemical_element ,Heavy metals ,010501 environmental sciences ,01 natural sciences ,Pollution ,Human fertilization ,chemistry ,Environmental chemistry ,Micro-X-ray fluorescence ,Soil water ,Environmental Chemistry ,Binding site ,Waste Management and Disposal ,Two-dimensional nuclear magnetic resonance spectroscopy ,0105 earth and related environmental sciences - Abstract
Understanding how heavy metals bind and interact in soils is essential for predicting their distributions, reactions and fates in the environment. Here we propose a novel strategy, i.e., combining two-dimensional correlation spectroscopy (2D COS) and synchrotron radiation based spectromicroscopies, for identifying heavy metal binding to functional groups in soils. The results showed that although long-term (23 yrs) organic fertilization treatment caused the accumulation of Cd (over 3 times) in soils when compared to no fertilization and chemical fertilization treatments, it significantly (p0.05) reduced the Cd concentration in wheat grain. The 2D COS analyses demonstrated that soil functional groups controlling Cd binding were modified by fertilization treatments, providing implications for the reduced bioavailability of heavy metals in organic fertilized soils. Furthermore, correlative micro X-ray fluorescence spectromicroscopy, electron probe micro-analyzer mapping, and synchrotron-radiation-based FTIR spectromicroscopy analysis showed that Cd, minerals, and organic functional groups were heterogeneously distributed at the micro-scale in soil colloids. Only minerals, rather than organic groups, had a similar distribution pattern with Cd. Together, this strategy has a potential to explore the interactions and binding sites among heavy metals, minerals and organic components in soil.
- Published
- 2017
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.