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51.
采用模拟重金属废水的正交试验设计,进行赭石对模拟重金属废水的吸附效果研究,探讨pH、赭石加入量和振荡时间等影响因素对吸附效果的影响。结果表明,在一定pH、赭石加入量和振荡时间条件下,赭石对6种重金属(Pb、Cd、Mn、Zn、Cr和Ni)均有较好吸附效果,对Pb、Cd、Mn、Zn和Cr的最大吸附率可达100%,对Ni的吸附率达8963%。处理后废水中重金属达到污水排放标准。各影响因素对Mn、Zn和Cr吸附效率的影响大小表现为:pH>赭石加入量>振荡时间,Ni和Cd表现为:赭石加入量>pH>振荡时间,Pb表现为:pH>振荡时间>赭石加入量。赭石对废水中重金属吸附的最佳条件为赭石加入量40 g/L,pH 10~10.5,振荡时间2 h。  相似文献   
52.
利用UVC去除低浓度苯的实验研究   总被引:3,自引:1,他引:2  
探讨了不同实验参数对苯的UVC去除效果的影响,获得了苯的去除率与苯的初始浓度、气体流量、相对湿度和氧气含量等参数之间的关系。数据表明,在实验条件范围内,苯的去除率的倒数与苯初始浓度、气体流量之间为线性关系;苯的去除率随相对湿度的增加呈现先升高后缓慢降低的关系,最佳相对湿度值在30%~50%之间;苯的去除率随氧气量的增加而缓慢增加;波长为185+254 nm的UV与254 nm的UV相比净化效果更为理想。还分析了苯降解产生的中间产物,探讨了苯的降解机理。  相似文献   
53.
湖岸缓冲带反硝化作用的研究进展   总被引:2,自引:0,他引:2  
反硝化作用是湖岸缓冲带去除硝酸盐的重要途径。湖岸缓冲带是联系陆地与湖泊生态系的纽带,不仅为许多动植物提供适宜生境,而且通过反硝化作用能去除地下水中的硝酸盐,提高湖泊水质。概述不同检测反硝化速率的方法,并对比各种方法的优点与缺点。阐述反硝化作用的影响因素:厌氧环境、有机碳、湖岸坡度、缓冲带坡度、pH与温度、硝酸盐浓度。介绍反硝化速率模型的研究开发状况。最后,提出了目前国内外反硝化研究中存在的不足及发展方向。  相似文献   
54.
固定化假单胞菌降解油烟废气的研究   总被引:1,自引:0,他引:1  
马艳玲 《环境工程学报》2009,3(10):1856-1860
将从受油烟废气污染严重的土壤中分离筛选的具有较强降解油烟能力的假单胞菌利用活性炭为填料吸附固定后制成填料床生物反应器。实验考察了进气浓度、气体流量、气体停留时间、容积负荷等对油烟去除率的影响,初步研究了生物反应器的抗冲击能力。结果表明,活性炭填料对菌体具有良好的吸附能力,当油烟进气浓度小于100 mg/L,气体流速小于8 L/h,停留时间大于30 s,容积负荷为2.6~18.9 g油烟废气/(m3·h),生物反应器的降解效率可达到95%以上,且活性炭填料床反应器具有较强的抗冲击能力。  相似文献   
55.
从某印染厂废水排放出口的污泥中分离到一株活性艳蓝X-BR染料高效降解菌LPY68-14,经生理生化鉴定,该菌为埃希氏菌(Escherichia sp.).研究了影响菌株LPY68-14降解效果的因素,实验结果表明:在缺氧、质量分数为0.2%葡萄糖为外加碳源、温度37℃、接种量4 mL、pH 7的最佳条件下,质量浓度为30 mg/L的活性艳蓝X-BR经菌株LPY68-14处理24 h后的降解率可达80%;当活性艳蓝X-BR质量浓度为100~400 mg/L时,该菌处理48 h后的降解率可稳定在70%左右.  相似文献   
56.
微电解-催化氧化法处理高浓度甲醇废水   总被引:6,自引:2,他引:4  
采用微电解一催化氧化法处理某化工厂的高浓度甲醇生产废水。实验结果表明:在进水pH为2.0、铁炭质量比为2、微电解时间为14h、空气流量为500mL/min的条件下,废水经微电解处理后,出水COD由原来的约7000mg/L降至约1000mg/L,COD去除率达85%以上;在过滤后微电解出水COD约为950mg/L、微电解出水pH为6.5、空气流量为300mL/min、催化氧化时间为3h时的条件下,经催化氧化处理后,出水COD降至100mg/L以下,出水水质达到GB8978--1996《污水综合排放标准》的二级标准。  相似文献   
57.
马英楠 《安全》2009,30(10):15-18
随着安全社区在我国推广工作的不断深入开展,与之相适应的科学方法的运用水平与有效性已经显得相对不足。由于安全社区建设和伤害预防工作涉及社会学、管理学、预防医学、安全科学、心理学等多个学科,其学科跨度及巨大复杂性,使得没有任何一个学科可以单独地应用完成,并且它具有许多不同于其他学科的特殊性,因此,关于安全社区建设过程中的科学方法研究十分必要。  相似文献   
58.
The 'Campo de Gibraltar' region is a very industrialized area where very few air pollution studies have been carried out. Up to date, no model has been developed in order to predict air pollutant levels in the different towns spread in the region. Carbon monoxide (CO), Sulphur dioxide (SO(2)) and suspended particulate matter (SPM) series have been investigated (years 1999-2000-2001). Multilayer perceptron models (MLPs) with backpropagation learning rule have been used. A resampling strategy with two-fold crossvalidation allowed the statistical comparison of the different models considered in this study. Artificial neural networks (ANN) models were compared with Persistence and ARIMA models and also with models based on standard Multiple Linear Regression (MLR) over test sets with data that had not been used in the training stage. The models based on ANNs showed better capability of generalization than those based on MLR. The designed procedure of random resampling permits an adequate and robust multiple comparison of the tested models. Principal component analysis (PCA) is used to reduce the dimensionality of data and to transform exogenous variables into significant and independent components. Short-term predictions were better than medium-term predictions in the case of CO and SO(2) series. Conversely, medium-term predictions were better in the case of SPM concentrations. The predictions are significantly promising (e.g., d (SPM 24-ahead) = 0.906, d (CO 1-ahead) = 0.891, d (SO2 1-ahead) = 0.851).  相似文献   
59.
The middle and lower reaches of the Yangtze River basin have the most representative and largest concentration of freshwater lakes in China. However, the size and number of these lakes have changed considerably over the past century due to the natural and anthropogenic impact. The lakes, larger than 10 km2 in size, were chosen from relief maps and remotely sensed images in 1875, 1950, 1970, 1990, 2000, and 2008 to study the dynamics of lakes in the middle and lower reaches of the Yangtze River basin and to examine the causes and consequences of these changes. Results indicated that there was a dramatic reduction in lake areas, which decreased by 7,841.2 km2 (42.64 %) during the study period (1875–2008), and the number of lakes in this region changed moderately. Meanwhile, a large number of lakes in the middle and lower reaches of the Yangtze River basin were directly converted into paddy fields, ponds, building lands, or other land-use types over the study period. Therefore, all kinds of lake reclamation should be identified as the major driving factors for the loss of lake in this region. Furthermore, flooding, soil erosion, and sedimentation were also the main factors which triggered lake changes in different periods. Some wetland conservation and restoration projects have been implemented since the 1970s, but they have not reversed the lake degradation. These findings were of great importance to managers involved in making policy for the conservation of lake ecosystems and the utilization of lake resources.  相似文献   
60.
The aim of the study was to investigate the transfer of toxic metals from honeybee workers (Apis mellifera L.) to bee honey in relation to the ecological state of the environment. The materials of the study consisted of samples of honeybee bodies and varietal honeys taken from the same apiary located in three areas: R1—urbanized (16), R2—ecologically clean (16) and R3—industrialized (15) of south-eastern Poland. The contents of 14 elements in all tested samples, including toxic metals (Cd, Pb, Hg, Al, Ni, Tl) as well as bioelements (K, Mg, Ca, Mn, Fe, Zn, Cu, Se), were analysed by the ICP-OES method with prior microwave mineralization. The concentrations of the majority of the studied elements, excluding aluminum and lead, were significantly higher in bee bodies than in honey samples (P?<?0.05). The pollution of bee bodies by toxic metals was dependent on the environmental cleanliness, and the most pollution was observed in the industrialized area. The bee body was the most effective barrier for Cd and Tl transfer to the honey, while the level of Ni was similar in both tested materials. The Al concentration was significantly higher in honey than bee bodies (14.81?±?24.69 and 6.51?±?5.83 mg kg?1, respectively), which suggests the possibility of secondary contamination of honey. The greatest sensitivity to heavy metal pollution was observed in honeydew honey compared to nectar honeys (P?<?0.05). It was proved for the first time that bees work as biofilters for toxic metals and prevent honey contamination.  相似文献   
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