Effects of chitosan on a submersed plant, HydriUa verticillata, were investigated. Results indicated that H. verticillata could prevent ultrastructure phytotoxicities and oxidativereaction from polluted water with hig...Effects of chitosan on a submersed plant, HydriUa verticillata, were investigated. Results indicated that H. verticillata could prevent ultrastructure phytotoxicities and oxidativereaction from polluted water with high chemical oxygen demand （COD）. Superoxide dismutase （SOD） activity and malondialdehyde （MDA） contents in H. verticillata treated with 0.1% chitosan in wastewater increased with high COD （980 rag/L） and decreased with low COD （63 mg/L）, respectively. Ultrastructural analysis showed that the stroma and grana of chloroplast basically remained normal. However, plant ceils from the control experiment （untreated with chitosan） were vacuolated and the cell interval increased. The relict of protoplast moved to the center, with cells tending to disjoint. Our findings indicate that wastewater with high COD concentration can cause a substantial damage to submersed plant, nevertheless, chitosan probably could alleviate the membrane lipid peroxidization and ultrastructure phytotoxicities, and protect plant cells from stress of high COD concentration polluted water.展开更多
The potential use of Myriophyllum spicatum L. biomass as a biosorbent for the removal of copper（ Ⅱ ） from aqueous solution was investigated in laboratory condition. The sorption experiments were undertaken to obtai...The potential use of Myriophyllum spicatum L. biomass as a biosorbent for the removal of copper（ Ⅱ ） from aqueous solution was investigated in laboratory condition. The sorption experiments were undertaken to obtain copper（ Ⅱ ） biosorption properties of M. spicatum L., i.e. equilibrium time, the maximum capacity, and rate constants. Copper（ Ⅱ ） biosorption was fast and equilibrium was attained within 35 min at initial copper（ Ⅱ ） concentration of 6 mg/L. Different isotherm models including the Langmuir, Freundlich, Temkin and Redlich-Peterson model, were used to investigate the sorption capacity and isotherm. These models showed an excellent match with the experimental data except for the Freundlich model. According to the Langmuir coefficients, the maximum sorption capacity of copper onto M. spicatum L. was 10.80 mg/g. The kinetics of copper（ Ⅱ ） sorption was also analysed and rate constants were derived. It was found that the overall sorption process was best described by the pseudo second-order equation, and that intraparticle diffusion was not the rate determining step. The results of this study showed that M. spicatum L. can be considered as useful vehicles for the removal and recovery of copper（ Ⅱ ） from aqueous solutions.展开更多
基金Project supported by the National Basic Research Program of China (No. 2002CB412307)the Hi-Tech Research and Development Program (863) of China (No. 2002AA601013).
文摘Effects of chitosan on a submersed plant, HydriUa verticillata, were investigated. Results indicated that H. verticillata could prevent ultrastructure phytotoxicities and oxidativereaction from polluted water with high chemical oxygen demand （COD）. Superoxide dismutase （SOD） activity and malondialdehyde （MDA） contents in H. verticillata treated with 0.1% chitosan in wastewater increased with high COD （980 rag/L） and decreased with low COD （63 mg/L）, respectively. Ultrastructural analysis showed that the stroma and grana of chloroplast basically remained normal. However, plant ceils from the control experiment （untreated with chitosan） were vacuolated and the cell interval increased. The relict of protoplast moved to the center, with cells tending to disjoint. Our findings indicate that wastewater with high COD concentration can cause a substantial damage to submersed plant, nevertheless, chitosan probably could alleviate the membrane lipid peroxidization and ultrastructure phytotoxicities, and protect plant cells from stress of high COD concentration polluted water.
文摘The potential use of Myriophyllum spicatum L. biomass as a biosorbent for the removal of copper（ Ⅱ ） from aqueous solution was investigated in laboratory condition. The sorption experiments were undertaken to obtain copper（ Ⅱ ） biosorption properties of M. spicatum L., i.e. equilibrium time, the maximum capacity, and rate constants. Copper（ Ⅱ ） biosorption was fast and equilibrium was attained within 35 min at initial copper（ Ⅱ ） concentration of 6 mg/L. Different isotherm models including the Langmuir, Freundlich, Temkin and Redlich-Peterson model, were used to investigate the sorption capacity and isotherm. These models showed an excellent match with the experimental data except for the Freundlich model. According to the Langmuir coefficients, the maximum sorption capacity of copper onto M. spicatum L. was 10.80 mg/g. The kinetics of copper（ Ⅱ ） sorption was also analysed and rate constants were derived. It was found that the overall sorption process was best described by the pseudo second-order equation, and that intraparticle diffusion was not the rate determining step. The results of this study showed that M. spicatum L. can be considered as useful vehicles for the removal and recovery of copper（ Ⅱ ） from aqueous solutions.
