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761.
762.
Phytoremediation and its models for organic contaminated soils 总被引:9,自引:0,他引:9
Soil pollution has been attracting considerable public attentions over the last decades.Sorts of traditional physiochemical methods have been used to remove th organic pollutants from soils.However,the enormous costs and low efficiencies associated with these remediation technologies limit their availabilities.Phytoremediation is an emerging technology that uses plants to cleanup pollutants in soils.As overwhelmingly positive results have been shown,phytoremediation is a most economical and effective remediation technique for organic contaminated soils.In this paper phytoremediation and its models for organic contaminated soils are viewed.The mechanisms of phytoremediation mainly include the direct plant uptake of organic pollutants,degradation by plant-derived degradative enzymes,and stimulated biodegradation in plat rhizosphere.Phytoremediation efficiency is close related to physicochemical properties of organic pollutants, environmental characteristics,and plant types.It is no doubt that soil amendments such as surfactants improve the solubilities and availabilities of organic pollutants in soils.However,little information is available about effects of soil amendments on phytoremediation efficiencies.Phytoremediation models have been developed to imulate and predict the environmental behavior of organic pollutants,and progress of models is illustrated.In many ways phytoremediation is still in its initial stage,and recommendations for the future for the future research on phytoremediation are presented. 相似文献
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765.
不同来源腐殖酸的光解及过氧化氢对其影响 总被引:7,自引:0,他引:7
为探讨腐殖酸在环境中的行为及光解除去腐殖酸的可能性,利用大于290nm的模拟日光辐照,探讨了大骨节病病区、非病区腐殖酸和泥炭腐殖酸的光解过程和光解机理及过氧化氢对其光解的影响,发现随着光照时间的延长,腐殖酸水体系的总有机碳(TOC)含量降低,pH值下降,过氧化氢可以促进腐殖酸的光解,其光解过程遵循一级动力学规律。计算了不同来源腐殖酸光解的速率及光解半衰期,发现土壤和泥炭腐殖酸比大骨节病病区饮水中腐 相似文献
766.
767.
微波密封消解法快速测定CODcr 总被引:7,自引:1,他引:7
标准法──重铬酸钾法测定CODCr的缺点是测定时间长,氯离子干扰大。微波密封消解法对此进行了改进。实验结果表明,该法具有消解时间短,减轻了二次污染,准确度高,精密度好等优点,可同标准回流法等效使用。 相似文献
768.
Nearly 91% of organic pollutants in Hong Kong leachate could be effectively removed by the UASB(upflow anaerobic sludge blanket)process followed by the fenton coagulation.The COD(chemical oxygen demand)of leachate was lowered from an average of 5620 mg/L to 1910 mg/L after the UASB treatment at 37℃,and was further lowered to 513 mg/L after fenton coagulation.The remaining refractory residues could be further removed by plotochemical oxidation with the addition of H2O2.The BOD/COD ratio was greatly increased from 0.062 to 0.142,indicating the biodegradability of organic residues was improved.The photochemical oxidation for the fenton-coagulation supernatant was most effective at pH3-4,with the addition of 800 mg/L of H2O2,and UV radiation time of 30 minutes.The final effluent contained only 148 mg/L of COD,21 mg/L of BOD(biochemical oxygen demand)and 56 mg/L of TOC (total organic carbon). 相似文献
769.
Glucose plays a significant role in enhanced biological phosphorus removal (EBPR). Previous experimental studies have shown that in addition to acetate, glucose can induce and maintain a successful EBPR performance under certain operating procedures. Mathematical modeling of the EBPR metabolism is an important consideration that is necessary to produce a deeper insight into this process. In this study, four anaerobic reactions plus four aerobic reactions with fourteen kinetic constants are structured to describe the dynamic behavior of the key metabolic components in the glucose induced EBPR system. The development of the stoichiometric coefficients for the reactions is based on fundamental biochemical principles. The model describes the dynamics of the important storage compounds, which are considered separately from the active biomass. Sequential batch experiments were performed to find the optimum model parameters using sludges exhibiting stable EBPR from glucose fed system. The maximum specific substrate conversion rate in the glucose model is composed of two factors: the maximum specific rates of glucose direct conversion to PHV (q gv max ) and glucose conversion to glycogen q gl max , which are 14.1 and 699.7 C-mmol/C-mmol·h, respectively. The maximum specific rate of polyphosphate synthesis k pp max is 0.2 P-mmol/C-mmol·h. The model with the best-fit parameters satisfactorily simulates the dynamic behavior of the key components during both anaerobic and aerobic conditions. 相似文献
770.