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291.
交联菌丝体吸附剂的制备及其对Cr^3+的吸附特性   总被引:1,自引:0,他引:1  
深入研究了交联菌丝体吸附剂的制备工艺及其对Cr^3+的吸附特性。交联菌丝体吸附剂制备工艺简单,但在制备过程中,活化剂NaOH和交联剂的用量对吸附特性影响较大。与纯菌丝体吸附剂相比,交联菌丝体吸附剂表观吸附容量提高48%,达到49.83mg/g(pH=2.53,水溶液中的Cr^3+浓度为600mg/L),同时其机械强度明显增强。交联菌丝体吸附剂对Cr^3+的吸附特点是将沉淀法与吸附法相结合,将沉淀与吸附两过程合二为一,从而简化了处理工艺,降低了处理成本。  相似文献   
292.
Electrokinetics is an innovative technique for treating heavy metals contaminated soil, especially low pH soils such as the Chinese red soil (Udic Ferrisols). In this paper, a Cu-Zn contaminated red soil is treated by electrokinetics. When the Cu-Zn contaminated red soil was treated without control of catholyte pH during the electrokinetic treatment, the soil pH in the soil sections near cathode after the experiment was high above 6, which resulted in accumulation of large amounts of Cu and Zn in the soil sections with such high pH values. Compared to soil Cu, soil Zn was more efficiently removed from the soil by a controlled electrokinetic method. Application of lactic acid as catholyte pH conditioning solution caused an efficient removal of Cu and Zn from the soil. Increasing the electrolyte strength (salt concentration) of the conditioning solution further increased Cu removal, but did not cause a significant improvement for soil Zn. Soil Cu and Zn fractions after the electrokinetic treatments were analyzed using sequential extraction method, which indicated that Cu and Zn precipitation in the soil section closest to the cathode in the treatments without catholyte pH control limited their removal from the soil column. When the catholyte pH was controlled by lactic acid and CaCl(2), the soil Cu and Zn removal percentage after 554 h running reached 63% and 65%, respectively. Moreover, both the residual soil Cu and Zn concentrations were lower than 100 mg kg(-1), which is adequate and meets the requirement of the Chinese soil environmental quality standards.  相似文献   
293.
环境中内分泌干扰物质的研究概述   总被引:4,自引:0,他引:4  
在总结最新文献的基础上,就环境中的内分泌干扰物质的概念,研究背景,研究方法,在环境中的分布情况作了简单综述和介绍,并对有待开展的研究提出了建议,为国内在环境内分泌干扰物方面的研究提供参考。  相似文献   
294.
多级雾化超重力旋转床是一种新型的强化传质设备 ,适合于大流量的废气处理。本文选择NaOH Ca(OH) 2双碱法烟气脱硫工艺进行了实验研究 ,考察了再生液的PH0 值、液气比及气体中的SO2 初始浓度等对脱硫率的影响  相似文献   
295.
深圳市观澜河流域地处南亚热带,受自然因素和人为因素的影响,流域存在着严重的水土流失,改革开放以来,流域的大片土地被开发成了工业开发区。工业开发区在建设阶段,机械夷平土地所形成的各种松散的堆积坡,引起了新的水土流失类型。本文研究和探讨了该流域的水土流失规律及水土流失对流域水环境的影响。  相似文献   
296.
UV-C辐射增强对绿化树种膜质过氧化及抗氧化酶的影响   总被引:4,自引:2,他引:4  
陈忠林  马溪平  张利红  王杰 《生态环境》2006,15(5):1014-1017
采用叶片试验法研究了模拟紫外辐射(UV-C)胁迫对3种绿化树种叶片膜质过氧化及抗氧化酶产生的影响。实验结果表明:UV-C辐射处理使连翘ForsythiasuspensaVahl和垂柳Salixbabylonica叶片的叶绿素质量分数增加,但使水蜡树FraxinuschinesisRoxb.叶片的叶绿素质量分数降低。UV-C辐射处理增加连翘和垂柳叶片的SOD活性,而水蜡的SOD活性则表现为先升高随后降低的变化趋势;辐射处理对水蜡树和垂柳POD活性影响不大,但使连翘POD活性先升高随后降低;辐射处理明显降低水蜡树和连翘的CAT活性,而垂柳的则先升高后降低。辐射处理导致MDA含量增加。  相似文献   
297.
This paper reports on the degradation of 4-aminophenol using hydrogen peroxide as oxidizer and the enzyme from Serratia marcescens AB 90027 as catalyst. The effecting factors during degradation and the degrading mechanism were studied. Also, the location of the enzyme in the cell, which could catalyze the degradation of 4-aminophenol, was analyzed. The results showed that to degrade 50 mL of 4-aminophenol whose concentration was 500 mg/L, the optimal conditions were: volume of H2O2 = 3 mL, temperature = 40–60°C and pH = 9–10. In the degradation process, 4-aminophenol was first converted to benzoquinone and NH3, then organic acids including maleic acid, fumaleic acid, and oxalic acid were formed, and then finally CO2 and H2O were generated as final products. The enzyme that could catalyze the degradation of 4-aminophenol was mainly extracellular enzyme.  相似文献   
298.
The fractional dispersion model for natural rivers, extended by including a first order reaction term, contains four parameters. In order to estimate these parameters a fractional Laplace transform-based method is developed in this paper. Based on 76 dye test data measured in natural streams, the new parameter estimation method shows that the fractional dispersion operator parameter F is the controlling parameter causing the non-Fickian dispersion and F does not take on an integer constant of 2 but instead varies in the range of 1.4–2.0. The adequacy of the fractional Laplace transform-based parameter estimation method is determined by computing dispersion characteristics of the extended fractional dispersion model and these characteristics are compared with those observed from 12 dye tests conducted on the US rivers, including Mississippi, Red, and Monocacy. The agreement between computed and observed dispersion characteristics is found to be good. When combined with the fractional Laplace transform-based parameter estimation method, the extended fractional dispersion model is capable of accurately simulating the non-Fickian dispersion process in natural streams.  相似文献   
299.
为查明硫酸工业中主要重金属的危害以及不同制酸工艺产生的危害差异,对辽宁省主要生产硫酸企业进行了调研,并应用MEG法,对矿石原料中重金属的含量进行了数学模型分析。  相似文献   
300.
The characteristics of vertical and horizontal variations of lead element (Pb) in soil-plant system of vertical zone in Changbai Mountain National Nature Reserve(CNNR)were studied.The results showed that Pb concentrations in soils of vertical zone are all above 25mg/kg,and the average Pb concentration of each soil zone negatively correlates its degree of variation,i.e.brown coniferous forest soil zone has the lowest average Pb concentration of four soil zones,and the highest horizontal variation;however,mountain soddy forest soil has the highest average Pb concentration,and the lowest horizontal variation;the average concentration of plant Pb of each plant zone is lower than the worldwide average level of Pb in plant(Clarke),respectively,and plant Pb content order is consistent with soil Pb content order,but their horizontal variations are different from those in soil zones,the variation of mountain tundra forest zone is highest,but Betula ermanii forest zoner the lowest.Vertical variation of plant Pb is obviously higher than that in soils with variation coefficient of 89.76%;the enrichment capability of plant for Pb is depended on the plant types and the different organs of plant;parent material and parent rock,pH values,soil organic matter and soil particle fraction etc.are the main factors influencing variations of Pb contant in soil-plant system of vertical zone in CNNR.  相似文献   
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