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31.
利用粉煤灰合成沸石处理重金属污水研究   总被引:10,自引:0,他引:10  
本研究中利用粉煤灰合成沸石对含有Cu^2 、Pb^2 、Cd^2 的制备水样进行批处理振荡实验,其吸附容量分别为9.56、0.89和0.25mg/l。实验证明,用合成沸石处理含重金属离子污水达到平衡所需的时间约为3h。对污水中重金属离子的去除率随pH值降低而降低,随沸石用量增加而增加。同等条件下,利用粉煤灰处理含Cu^2 的污水,其吸附容量仅为6.49mg/l,低于合成沸石。  相似文献   
32.
抗震液化的总应力合成分析方法   总被引:2,自引:0,他引:2  
基于总应力动力分析法,运用二维显式有限差分程序FLAC对某大坝在地震荷载作用下的动力响应进行模拟分析。编制了分析大坝液化的数值模型的分析模块并与FLAC接口。分别考虑了水平、竖向地震荷载以及两个方向的耦合和不同水位深度对大坝动力特性的影响,得到了大坝在地震荷载作用下液化区域和位移矢量的分布态势。  相似文献   
33.
Laboratory incubation trials were conducted to investigate the effects of several factors on the persistence as well as the dissipation of three synthetic pyrethroid pesticides in red soils obtained from the Yangtze River Delta region in China. The pyrethroids selected for investigation were cypermethrin, fenvalerate, and deltamethrin, which continue to be used extensively to control pests on farmland in the region despite the concern that they are highly toxic to certain vertebrate and mammalian species. Data from this exploratory study showed that the dissipation half-lives (T 1/2) tended to correlate with soil pH and soil organic matter contents, but not with soil cation-exchange capacity. The T 1/2 values were seen to be shorter in soil samples fertilized with glucose than without. The rates of pyrethroid dissipation also tended to increase with increasing initial soil concentration, but were largely unaffected by whether the pesticides were present in the soil separately or as a mixture. Another noteworthy observation is that microbial activity appeared to dominate the degradation process. Findings of this type could offer valuable clues for future research directions in reducing pesticide persistence in soil, which in turn could lead to the ultimate reduction of environmental pollution caused by pyrethroid application to farmland in the region. Project supported by Chinese Academy of Sciences (Project No. KSCX2-YW-N-038) and the National Key Basic Research Support Foundation (973), China (No. 2002CB4108010).  相似文献   
34.
氯菊酯农药间接酶联免疫吸附测定法的建立   总被引:11,自引:1,他引:10  
刘廷凤  刘亚子  孙成 《环境科学》2006,27(2):347-350
为测定环境样品中氯菊酯农药残留,用活泼酯法将氯菊酯半抗原(Py)与卵白蛋白(OVA)偶联,制备合成抗原Py-OVA作包被原,建立间接竞争酶联免疫吸附测定法.方阵滴定确定了抗血清最佳稀释度(1∶2 500),包被抗原的最适工作浓度0.45μg/mL,并建立了标准工作曲线.工作曲线表明在10~800μg/L浓度范围内呈良好的线性关系,回收率>97%.  相似文献   
35.
拟除虫菊酯对大鼠脑片谷氨酸递质释放的影响   总被引:4,自引:0,他引:4       下载免费PDF全文
应用脑片放射性同位素标记神经递质释放实验,体外观察拟除虫菊酯类杀虫剂对大鼠额叶皮层脑片兴奋性氨基酸递质谷氨酸释放过程的影响。结果显示,在20μmol/L剂量下,4种拟除虫菊酯(溴氰菊酯、北京菊酯Ⅱ号、Ⅲ号和氯菊酯)对脑片静息态谷氨酸基础释放无明显作用。而化学结构中含氰基的拟除虫菊酯可促进额叶皮层脑片在50mol/LKCL去极化状态下谷氨酸的释放,与溶剂对照比较,溴氰菊酯(20μmol/L)可使脑片谷氨酸释放增加28.8%。  相似文献   
36.
以粉煤灰为原料,采用优化改进的水热晶化一步法合成沸石。借助FTIR、XRD和SEM对沸石理化特性进行表征,分析水中双组分污染物亚甲基蓝(MB)和Cr(Ⅲ)的共吸附去除特性。结果表明,合成沸石产物呈菱形或多面体形,在XRD图谱中可见NaP1型沸石特征峰。共吸附过程为准二级反应,以化学吸附为速率控制步骤。Langmuir和Freundlich等温线方程都能有效地描述反应过程,298 K条件下,沸石对MB和Cr(Ⅲ)的理论最大吸附量分别为7.8186 mg/g和8.8889 mg/g。吸附过程自发、吸热,反应后体系自由度降低,推测吸附位点的直接竞争为MB和Cr(Ⅲ)去除的主导机制之一。  相似文献   
37.
Zeolite synthesized from fly ash (ZFA) without modification is not efficient for the purification of NH4+ and phosphate at low concentrations that occur in real effluents, despite the high potential removal capacity. To develop an effective technique to enhance the removal efficiency of ammonium and phosphate at low concentrations, ZFA was modified with acid treatment and the simultaneous removal of ammonium and phosphate in a wide range of concentration was investigated. It was seen that when compared with untreated ZFA, only the treatment by 0.01 mol/L of H2SO4 significantly improved the removal efficiency of ammonium at low initial concentrations. The behavior was well explained by the pH effect. Treatment by more concentrated H2SO4 led to the deterioration of the ZFA structure and a decrease in the cation exchange capacity. Treatment by 0.01 mol/L H2SO4 improved the removal efficiency of phosphate by ZFA at all initial P concentrations, while the treatment by concentrated H2SO4 (≥0.9 mol/L) resulted in a limited maximum phosphate immobilization capacity (PIC). It was concluded that through a previous mild acid treatment (e.g. 0.01 mol/L of H2SO4), ZFA can be used in the simultaneous removal of NH4+ and P at low concentrations simulating real effluent.  相似文献   
38.
PCDD/Fs have been become a serious issue because of their toxicological effects and associated adverse health implications.In this study,the gliding arc plasma was tested for treatment of polychlorinated dibenzo-p-dioxins(PCDDs)and polychlorinated dibenzofurans (PCDFs),which was synthesized from pentachiorophenol in atmospheric condition at 35℃with or without the catalysis of CuCl_2. From the experiment,we found that the destruction efficiency of PCDD/F homologues after gliding was discharge ranged from 25% to 79%.This result demonstrates that gliding arc plasma is an effective technology to decompose PCDDs/Fs in flue gas.A plausible degradation mechanism for PCDD/Fs by gliding arc was discussed.Finally,a multistage reactor structure of gliding arc was proposed to upgrade removal efficiency for PCDD/Fs.  相似文献   
39.
从城市化内涵出发,基于人口、经济发展、居民生活和地域环境构建了反映城市化发展水平的评价指标体系。然后,运用综合评价方法,对江苏省13个城市的城市化发展水平进行了评价分析,并通过聚类分析对其进行分类,目的是找出各城市之间的优势和差距。同时借助于GIS技术手段,将这种城市化差异反映在空间区域上,从而有针对性地制定提高江苏省各区域之间城市化水平的对策。  相似文献   
40.
本文选取泥炭、生物质炭、木炭和活性炭4种含碳材料,结合以经济底栖生物菲律宾蛤仔(Venerupis philippinarum)为受试生物的生物累积实验和Tenax连续萃取法,阐述不同碳质对沉积物中4种菊酯类农药生物有效性的影响,并将Tenax萃取结果与底栖生物的累积结果进行了相关分析。结果表明,碳质的添加导致沉积物中菊酯类农药的快速脱附组分(Frap)降低,极慢速脱附组分(Fv s)增大,生物有效性降低,且4种碳质对Frap的影响有所不同,然而因为菊酯类农药的理化性质,Frap的差异并不显著。Tenax 6 h和24 h的单点萃取组分与快速脱附组分相关性显著(P0.0001),基本可以代替完整的脱附动力学评价生物有效性,但是对于组成复杂,有机碳(OC)和黑炭(BC)含量高的沉积物进行研究评价时仍应注意由此产生的偏离。Tenax快速脱附组分与2种底栖生物累积结果之间具有显著的相关性(R2=0.38,P0.0001),表明在OC和BC含量不同的沉积物中,Tenax萃取技术也可以预测菊酯类农药在经济底栖生物菲律宾蛤仔体内的累积量,进而为沉积物中HOCs的环境质量和相关水产品的质量评估提供更为快捷、有效的参考依据。  相似文献   
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