Water
·
2017
·Vol. 9
·期 5
·326
·
IF 1.832
Ting Zhang,Jian He,Xingzhang Luo
Due to the fact that not all eutrophic lakes have cyanobacteria blooms, we hypothesized Fe may be another important limiting factor which regulates cyanobacteria bloom formation. We tested the hypothesis by batch cultures of bloom-forming Cyanobacterium,Microcystis aeruginosawith different ethylenediaminetetraacetic acid (EDTA)-Fe concentrations (0.5–6.0 mg/L), three levels of initial biomass, and excessive N and P (N = 4.2 mg/L, P = 0.186 mg/L) to simulate dynamically a cyanobacteria bloom in eutrophic conditions. The effect of EDTA and Fe uptake kinetics byM. aeruginosawere also examined. Results showedM. aeruginosagrowth rate positively correlated with EDTA-Fe concentration and negatively correlated with biomass. Maximal biomass ofM. aeruginosawas determined by Fe availability and initial biomass. EDTA could decrease both Fe availability and toxicity. Based on experimental results, a conceptual model of how Fe availability regulates cyanobacterial biomass in eutrophic lakes was developed. This study demonstrated bioavailable Fe is a potential limiting factor in eutrophic lakes that should be included in eutrophication management strategies.Keywords:Microcystis;eutrophication control;freshwater;Fe availability
研究领域:
环境科学
·
生态学
✓ 已验证
DOI
高影响因子
PLANT AND SOIL
·
2014
·Vol. 382
·期 1
·103-115
·
IF 3.235
Duan Dechao,Peng Cheng,Xu Chen,Yu Mingge,Sun Lijuan,Worden Natasha,Shi Jiyan,Hu Tiandou
Background and aims Metal species in rhizosphere soil profoundly influence their mobility and phytoavailability. Clarifying the speciation transformation of heavy metals helps understand their translocation and accumulation in plants. Methods Single extraction, selective sequential extraction (SSE) and X-ray absorption near-edge structure (XANES) spectroscopy were employed to investigate the speciation transformation of lead (Pb) and its influence on metal accumulation in tea plants after the addition of tea polyphenols (TPs). Results Pb content was decreased in young leaves and stems, whereas increased in roots, after TPs were amended to soil. Both SSE and XANES analysis suggested bioavailable Pb was transformed to organically bound Pb after the addition of TPs. The increased percentage of organically bound Pb might be fixed in the cell wall of plant root through a ternary complex formed between the Pb-organic matter complex and cell wall components. Therefore, Pb translocation from roots to young tissues was decreased. Conclusions Pb phytoavailability change was driven by its speciation transformation after the addition of TPs. Combined SSE and XANES spectroscopy represent powerful tools to study metal speciation transformation in plant and soil systems.
研究领域:
环境科学
·
植物学
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL POLLUTION
·
2018
·
IF 4.358
Xiang Wu,Wei Wang,Lizhong Zhu
The mechanism of enhanced accumulation of organic contaminants in crops with engineered nanomaterials (ENMs) were investigated by co-exposure of crops ( Ipomoea aquatica Forsk (Swamp morning-glory), Cucumis sativus L. (cucumber), Zea mays L. (corn), Spinacia oleracea L. (spinach) and Cucurbita moschata (pumpkin))to a range of chemicals (polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs) and polybrominated diphenyl ether (PBDE)) and ENMs (TiO 2 , Ag, Al 2 O 3 , graphene, carbon nanotubes (CNTs)) in soil. Induced by 50 mg kg −1 graphene co-exposure, the increase range of BDE-209, BaP, p,p′ -DDE, HCB, PYR, FLU , ANT , and PHEN in the plants were increased in the range of 7.51–36.42, 5.69–32.77, 7.09–59.43, 11.61–66.73, 4.58–57.71, 5.79–109.07, 12.85–109.76, and15.57–127.75 ng g −1 , respectively. The contaminants in ENMs-spiked and control soils were separated into bioavailable, bound and residual fractions using a sequential ultrasonic extraction procedure (SUEP) to investigate the mechanism of the enhanced accumulation. The bioavailable fraction in spiked soils showed no significant difference ( p > 0.05) from that in the control, while the bound fraction increased in equal proportion ( p > 0.05) to the reduction in the residual fraction. These results implied that ENMs can competitively adsorbed the bound of organic contaminants from soil and co-transferred into crops, followed by a portion of the residual fraction transferred to the bound fraction to maintain the balance of different fractions in soils. The mass balance was all higher than 98.5%, indicating the portion of degraded contaminants was less than 1.5%. These findings could expand our knowledge about the organic contaminants accumulation enhancement in crops with ENMs.
研究领域:
环境科学
·
植物学
·
农业科学
✓ 已验证
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2014
·Vol. 21
·期 14
·8620-8630
·
IF 2.757
Gao Huipeng,Ma Jing,Xu Li,Jia Lingyun
Organic matter (OM) plays a vital role in controlling polycyclic aromatic hydrocarbon (PAH) bioavailability in soils and sediments. In this study, both a hydroxypropyl-β-cyclodextrin (HPCD) extraction test and a biodegradation test were performed to evaluate the bioavailability of phenanthrene in seven different bulk soil/sediment samples and two OM components (humin fractions and humic acid (HA) fractions) separated from these soils/sediments. Results showed that both the extent of HPCD-extractable phenanthrene and the extent of biodegradable phenanthrene in humin fraction were lower than those in the respective HA fraction and source soil/sediment, demonstrating the limited bioavailability of phenanthrene in the humin fraction. For the source soils/sediments and the humin fractions, significant inverse relationships were observed between the sorption capacities for phenanthrene and the amounts of HPCD-extractable or biodegradable phenanthrene ( p < 0.05), suggesting the importance of the sorption capacity in affecting desorption and biodegradation of phenanthrene. Strong linear relationships were observed between the amount of HPCD-extractable phenanthrene and the amount degraded in both the bulk soils/sediments and the humin fractions, with both slopes close to 1. On the other hand, in the case of phenanthrene contained in HA, a poor relationship was observed between the amount of phenanthrene extracted by HPCD and the amount degraded, with the former being much less than the latter. The results revealed the importance of humin fraction in affecting the bioavailability of phenanthrene in the bulk soils/sediments, which would deepen our understanding of the organic matter fractions in affecting desorption and biodegradation of organic pollutants and provide theoretical support for remediation and risk assessment of contaminated soils and sediments.
研究领域:
环境科学
·
污染生态学
✓ 已验证
DOI
高影响因子
WATER AIR AND SOIL POLLUTION
·
2023
·Vol. 234
·期 2
·1-16
·
IF 2.9
Hua Li,Zhao Danyang,Wang Huining,Wei Ting
Shaanxi is an important agricultural province in China. The rapid development of agriculture has led to an increase in the use of pesticides, which has resulted in a serious pesticide pollution problem. In addition, assessing the total residue concentrations would overestimate the actual hazard of neonicotinoid pesticides, so it is essential to study the bioavailability of neonicotinoid pesticides. In the study, 115 soil samples collected from different areas from northern, central, and southern Shaanxi were used to determine the residues of four neonicotinoid pesticides: imidacloprid, acetamiprid, clothianidin, and thiamethoxam. An analytical method applied to assess the bioavailability of neonicotinoid pesticides was established, the bioavailability of different types of neonicotinoid pesticides and related factors affecting their bioavailability were determined, and the changes in the bioavailability of neonicotinoid pesticides in actual and simulated soils were explored. The results showed that the detection rates and residue levels of neonicotinoid pesticides varied in different regions of Shaanxi. By studying the bioavailability of neonicotinoid pesticides, it was found that the bioavailability of the four neonicotinoid pesticides was always: thiamethoxam > acetamiprid > imidacloprid > clothianidin, which may be related to their structural properties. Soil pH is positively related to the size of the bioavailability of neonicotinoid pesticides, while soil organic matter content and soil aging time are negatively related to the size of the bioavailability of neonicotinoid pesticides.
研究领域:
环境科学
·
农业科学
·
毒理学
✓ 已验证
DOI
高影响因子
Journal of Cleaner Production
·
2019
·
IF 6.395
Le Zhang,Jingxin Zhang,Kai-Chee Loh
Eco-friendly delivery carrier of trace metals is very significant to appropriate metal supplementation to improve metal bioavailability and prevent metal precipitation in anaerobic digesters . A novel encapsulated form of dry water (DW) additive was synthesized by the high-speed mixing of nickel ions solution with hydrophobic silica nanoparticles and was characterized using scanning electron microscope (SEM), nuclear magnetic resonance (NMR) and particle size analyzer. Nickel (Ni) was chosen as a model trace element. The encapsulated structure of DW additive and the feasibility of controlled release of Ni ions from DW additive in pure water and anaerobic digesters were verified. The optimal mixing speed for the highest methane yield of digesters with DW additive was determined as 800–1000 rpm. By varying stirring speed, controlled release of trace metal element (Ni) into digester was easily achieved during anaerobic digestion of food waste. The results showed that nickel ions delivery via DW additive significantly enhanced the metal bioavailability by 18.9–42.6% and process stability during 59 days of operation, resulting in an increase of 11.6–31.8% in methane yields compared to the controls. Pyrosequencing analysis indicated that bacterial communities were dominated by phyla Firmicutes , Bacteroidetes , Proteobacteria , Chloroflexi and Spirochaetes while methanogenic genus Methanolinea , Methanoculleus , Methanothrix , Methanomassiliicoccus and Methanospirillum were more abundant in archaea communities. Further, phyla Bacteroidetes , Proteobacteria and Methanoculleus were selectively enriched by the DW additive. Results indicated that it was feasible to apply the method of DW additive supplementation to enhance anaerobic digestion of food waste for biogas production by improving metal bioavailability.
研究领域:
环境科学
·
微生物学
✓ 已验证
DOI
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2020
·
IF 4.192
Jian Zhou,Min Li,Jiaqian Li,Zixuan Shao,Yiman Liu,Tiecheng Wang,Lingyan Zhu
As emerging alternatives of legacy perfluoroalkyl substances, 6:2 fluorotelomer sulfonate (6:2 FTS), 6:2 chlorinated polyfluoroalkyl ether sulfonates (6:2 Cl-PFESA), and perfluorophosphinates (C6/C6 and C8/C8 PFPiAs) are supposed to be partitioned to soil and highly persistent in the environment. The uptake of novel per- and polyfluoroalkyl substances (PFASs) by plants represents a potential pathway for their transfer in the food chain. In this study, the bioavailability of these four novel PFASs in soil and the bioaccumulation characteristics in greenhouse-grown wheat (Triticum aestivum L.), maize (Zea mays L.), soybean (Glycine max L. Merrill), and pumpkin (Cucurbita maxima L.) were investigated. The results indicated that these novel PFASs with higher hydrophobicity were more easily sequestrated in soil, and the fractions extracted by methanol could well describe their bioavailability, which could be stimulated by low-molecular-weight organic acids at rhizospheric concentrations. A negative relationship was found between root soil concentration factors (RSCFs) and hydrophobicity (log Kow) of the target PFASs. This correlation was also found in the translocation factors (TF) from roots to shoots. Furthermore, the uptake and transfer of the target PFASs were regulated by the protein contents in plant roots and shoots.
研究领域:
环境科学
·
农业
·
毒理学
·
植物生理学
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）