排序方式: 共有52条查询结果,搜索用时 15 毫秒
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Hailin Wang Haoqing Tang Zhaotie Liu Xin Zhang Zhengping Hao Zhongwen Liu 《环境科学学报(英文版)》2014,26(9):1879-1884
Montmorillonite (MMT) modified with chitosan (CTS, molecular weight = S x 104) was applied to remove heavy metal cations by using Co2+ as a model ion. An increase in MMT interlayer distance observed from X-ray diffraction indicates the intercalation of CTS into MMT. Together with the results of scanning electron microscopy and Fourier transform infrared spectroscopy, it was concluded that the composite material of CTS and MMT (CTS-- MMT) was prepared successfully. The mass ratio of CTS to MMT had a strong influence on the adsorption performance of CTS-MMT. The highest adsorption value of 150 mg/g was obtained over the composite material with CTS to MMT mass ratio of 0.25, which is much higher than those reported in other studies. The adsorption isotherms and kinetic results indicated that Co2+ was adsorbed over CTS-MMT in a multilayer model, and the chemical sorption of Co2+ was determined to be the rate-limiting step. 相似文献
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《环境科学学报(英文版)》2023,35(4):211-221
Antimony is more than an emerging pollutant in water but a scare resource. In this study, we report an adsorbent with the record capacity so far from the balanced view of Sb(III) and Sb(V). The composite adsorbent was fabricated by encapsulating hollow Fe3O4 nanosphere with the EDTA grafted chitosan, and it has superhigh adsorption capacity of for 657.1 mg/g for Sb(III) and 467.3 mg/g for Sb(V), respectively. The mechanism study reveals that the adsorption of Sb initializes from the Fe3O4, propagates along the chitosan with hydrogen bond, and terminates at the inner sphere complex with the EDTA moiety in the adsorbent. In view of the ultra-high adsorption capacity of the adsorbent, the recovered adsorbent that contains abundant (>36.4%) highly dispersed antimony nanoparticles (600-FCSE-Sb) is applied to Li-ion battery anode after reduction. This article provides a new idea for connecting water treatment and electric energy storage. 相似文献
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J. PLACENCIA A. RUDOLPH G. CABRERA G. CÁRDENAS M. YÉVENES 《Journal of environmental science and health. Part. B》2013,48(5):761-768
The study on the toxicity of chitosan diethyl phosphate (ChDP), a controlled release insecticide, on the activities of butyrylcholinesterase (BuChE) and acetylcholinesterase (AChE) in rainbow trout exposed to this pesticide was carried out. It was found that ChDP reduced BuChE activity in O. mykiss by a factor of eight at 6 days, with high fluctuation to the end of the exposition time at 12 days. The in vitro analysis of brain AChE treated with ChDP and Phenamiphos showed that it was competitively inhibited by both organophosphates. The values obtained for Km and Vmax for the AChE-ChDP (Km: 21.23 μ M; Vmax: 43.10 μ mol/min/g) and AChE-Phenamiphos (Km: 38.62 μ M; Vmax: 38.91 μ mol/min/g) systems were relatively low compared to values of the AChE (control) system (Km: 62.99 μ M; Vmax: 63.29 μ mol/min/g). Results reported in this study confirmed that chitosan diethyl phosphate performs similarly to organophosphate pesticides, producing inhibition in cholinesterases in rainbow trout. 相似文献
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脱乙酰甲壳质回收处理含铜废水 总被引:5,自引:0,他引:5
本文研究了利用脱乙酰甲壳质处理含铜污水时酸度、吸附时间及脱乙酰基程度对脱乙酰甲壳质吸附Cu2+量的影响.获得结果:吸附量可达65.0mg/g,洗脱被吸附的Cu2+后,脱乙酰甲壳质可再生;同时回收得纯度较高的CuSO4,Cu2+的回收率可达99.98%;将脱乙酰甲壳质装柱处理含Cu2+废液,流出液中Cu2+的含量远远低于国家排放标准. 相似文献
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Zerovalent iron encapsulated chitosan nanospheres - a novel adsorbent for the removal of total inorganic arsenic from aqueous systems 总被引:1,自引:0,他引:1
Evaluation of Chitosan zerovalent Iron Nanoparticle (CIN) towards arsenic removal is presented. Addition of chitosan enhances the stability of Fe(0) nano particle. Prepared adsorbent was characterized by FT-IR, SEM EDX, BET and XRD. It was found that, with an initial dose rate of 0.5 g L−1, concentrations of As (III) and As (V) were reduced from 2 mg L−1 to <5 μg L−1 in less than 180 min and the adsorbent was found to be applicable in wide range of pH. Langmuir monolayer adsorption capacity was found to be 94 ± 1.5 mg g−1 and 119 ± 2.6 mg g−1 at pH 7 for As (III) and As (V) respectively. Major anions including sulfate, phosphate and silicate did not cause significant interference in the adsorption behavior of both arsenite and arsenate. The adsorbent was successfully recycled five times and applied to the removal of total inorganic arsenic from real life groundwater samples. 相似文献
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A permeable system composed of a polyelectrolyte complex (PEC) membrane formed by alternated deposition of chitosan (CHI)
and carboxymethylcellulose (CMC) onto a porous solid substrate was investigated. The films, with thicknesses not superior
to 20 nm, were obtained by a self-assembly technique, i.e., by direct dipping of chemically cleaned porous glass membranes,
into concentrated polymeric precursor solutions. The resulting depositions have irregular structures and reduce the initial
membrane permeability, especially for higher flux velocities. Concerning filtration tests for herbicide removal in aqueous
medium, the chitosan deposition attained better results. A tentative model of binding involving hydrogen bonding and/or charge-transfer
to nonspecific sites available dynamically as a function of the conformational estate of the deposited polymers is proposed
for polysaccharide-herbicide interactions. 相似文献
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Piotr Rychter 《Journal of environmental science and health. Part. B》2013,48(8):681-692
Although there are many reports on the dangers posed by glyphosate, this herbicide is still one of the most popular and widely used total weed killers. Therefore, great effort should be made to minimize exposure to this herbicide and limit its losses into the environment. The aim of this study was to prepare a new formulation consisted of various molecular weight chitosans with glyphosate and their evaluation toward active substance release, phytotoxicity, and preliminary herbicidal efficiency. The phytotoxicity study of the obtained chitosan/glyphosate formulations was determined based on the Organisation for Economic Co-operation and Development 208 guideline. Among all tested formulations evaluated for phytotoxicity, that containing the highest molecular weight of chitosan was found to be the least toxic, showing simultaneously the most effective herbicidal activity against selected weeds. The release rate of glyphosate from the obtained formulations was dependent on the molecular weight and viscosity of chitosan. 相似文献