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81.
环境污染,实质就是资源能源的浪费。大庆石化二厂丙烯腈装置,从生产源头入手,着眼于生产全过程,节约能源.合理利用资源,最大限度地将原料转化为产品,回收“三废”中有用的物质,削减污染物的排放量;同时创造了可观的经济效益。  相似文献   
82.
吸附——光催化氧化法处理四环素废水   总被引:8,自引:0,他引:8  
以含ZnO,TiO2等无机半导体的沸石作为吸附剂和光催化剂,采用高压汞灯为光源对四环素溶液进行了处理。通过正交实验,考察了pH,光照时间,光照面积,沸石用量、初始浓度对四环素的影响,从实际应用出发,得出影响四环素降解的各因素的最佳取值及影响显著性次序。结果表明,pH对四环素分解影响最显著。该实验结果有助于制药工业废水的光催化处理研究以及新型复合水处理剂的开发与利用。  相似文献   
83.
A new dynamic air sampling system was devised and evaluated in conjunction with solid phase microextraction (SPME) fiber materials for extracting odor-causing volatile organic compounds (VOCs) present in swine building environments. Utilizing a standard solution consisting of 11 compounds (i.e., volatile fatty acids, indoles, and phenol), sampling times, volumes, and flow rates were adjusted to establish optimal extraction conditions. Results indicated that the sampling system was effective with the Carboxen/Polydimethylsiloxane (CAR/PDMS) fiber in extracting all 11 standard compounds. The best sampling conditions for the extraction were a 100-mL sampling vial subjected to a continuous flow of 100 mL/min for 60 min. The gas chromatographic analysis showed that the reproducibility was within acceptable ranges for all compounds (RSD=4.24-17.26% by peak areas). In addition, field tests revealed that the sampling system was capable of detecting over 60 VOCs in a swine house whose major components were identified by gas chromatography-mass spectrometry (GC-MS) and by their retention times as volatile fatty acids, phenols, indole, and skatole. The field tests also showed that considerably different levels of VOCs were present in various parts of the swine building.  相似文献   
84.
A field experiment was performed to evaluate water and nutrient balances in paddy rice culture operations during 2001-2002. The water balance analysis indicated that about half (50-60%) of the total outflow was lost by surface drainage, with the remainder occurring by evapotranspiration (490-530 mm). The surface drainage from paddy fields was mainly caused by rainfall and forced-drainage, and in particular, the runoff during early rice culture periods depends more on the forced-drainage due to fertilization practices. Most of the total phosphorus (T-P) inflow was supplied by fertilization at transplanting, while the total nitrogen (T-N) inflow was supplied by the three fertilizations, precipitation. and from the upper paddy field, which comprised 13-33% of the total inflow. Although most of the nutrient outflow was attributed to plant uptake. nutrient loss by surface drainage was substantial, comprising 20% for T-N and 10% for T-P. Water and nutrient balances indicate that reduction of surface drainage from paddy rice fields is imperative for nonpoint source pollution control. The simplified computer model, PADDIMOD, was developed to simulate water and nutrient (T-N and T-P) behavior in the paddy rice field. The model predicts daily ponded water depth, surface drainage, and nutrient concentrations. It was formulated with a few equations and simplified assumptions, but its application and a model fitness test indicated that the simulation results reasonably matched the observed data. It is a simple and convenient planning model that could be used to evaluate BMPs of paddy rice fields alone or in combination with other complex watershed models. Application of the PADDIMOD to other paddy rice fields with different agricultural environments might require further calibration and validation.  相似文献   
85.
以绿豆幼苗为材料,研究了外源一氧化氮(NO)处理对Cd~(2+)胁迫3天和8天时幼苗叶片和根系DNA含量、DNA链间交联程度以及叶片光合参数的影响。结果表明:单独Cd~(2+)胁迫导致叶片和根系DNA含量降低,DNA链间交联程度增加,叶片净光合速率、气孔导度和胞间隙CO2浓度降低,气孔限制值升高;与单独Cd~(2+)胁迫相比,NO和Cd~(2+)复合处理提高了叶片和根系DNA含量,降低了DNA链间交联程度,同时使叶片净光合速率和气孔导度升高,而使胞间隙CO2浓度和气孔限制值降低。结果说明,NO能缓解Cd~(2+)胁迫对绿豆幼苗DNA结构及其代谢的影响;Cd~(2+)胁迫抑制绿豆幼苗光合作用的主要原因是气孔因素,而NO主要通过提高幼苗叶片非气孔因素缓解了Cd~(2+)胁迫对幼苗光合作用的抑制。  相似文献   
86.
兰州市污水处理厂中典型抗生素的污染特征研究   总被引:11,自引:1,他引:10  
以9种磺胺类、4种氟喹诺酮类以及1种氯霉素为目标物,调查研究了它们在兰州市两个生活污水处理厂中的含量水平和去除特性,初步评估了其在受纳水体中的环境风险.结果表明:污水处理厂进水和出水中均有抗生素检出,浓度差别较大,进水中抗生素浓度在nd~55.25μg·L~(-1)之间,出水中浓度在nd~9.78μg·L~(-1)之间,脱水污泥中抗生素的平均浓度高于活性污泥;抗生素在整个污水处理工艺中的去除率为15.39%~100%,生物转化或降解作用是二级处理过程中的主要去除机制;污水处理厂排水增加了受纳水体中抗生素的浓度,是受纳水体中抗生素的来源之一,环境中低浓度、多种抗生素长期残留,存在较大的潜在风险.  相似文献   
87.
后金融危机时代,不管是金融市场,还是全球经济格局都发生了巨大变化。我国环保投融资存在着投资总量不足、投融资主体环保执行力不足,环保效果不佳等问题;为应对国际金融危机带来的深刻影响,有效化解后危机时代的发展困境,需要针对国家金融调控、信贷政策带来的变化,加倍关注资本市场体系发展的变化、融资渠道和融资工具的创新运用,通过制定更加具有灵活性和针对性的政府建设项目投融资规划和发展战略规划,以实现环保投融资平台的健康、可持续发展。在剖析存在问题原因的基础上提出了我国环保投融资策略,包括拓宽投融资渠道,构建多元投资主体,壮大环保投融资规模;加强管理,强化各投融资主体的环保执行力,提高环保投融资效益;创新环保投融资机制,建立多层次的环保投融资风险责任分担机制。  相似文献   
88.
次声监测技术是《全面禁止核试验条约》规定的四种监测技术手段之一,用来监测大气层中的核爆炸。根据次声台站监测过程中经常需要分析处理的次声信号类别,着重介绍分析爆炸、火山喷发、地震等令人震撼的事件以及微气压、海浪等日常司空见惯的自然现象激发次声波的机理及其信号特征。这些特征对于次声监测数据处理、去噪降噪、目标分类与识别等具有重要意义。  相似文献   
89.
负载β-环糊精纤维素纤维在污水处理中的应用研究   总被引:5,自引:0,他引:5  
以环氧氯丙烷作为交联剂 ,在碱性介质中将β-环糊精负载到粘胶纤维上 ,合成了负载β-环糊精的功能性纤维素纤维。考察了负载 β-环糊精的纤维素纤维对模拟水样中无机重金属离子、苯胺、苯酚及其对苯二酚的富集性能。实验结果表明 ,负载 β-环糊精的纤维素纤维对无机重金属离子 (Cu2 +、Cd2 +、Pb2 +)、苯胺、苯酚及其对苯二酚富集效果良好 ,Cu2 +、Pb2 +、Cd2 +富集容量分别达到 0 .2 42 8、0 .2 95 4、0 .3 43 8mmol/g,苯胺、苯酚及其对苯二酚富集容量分别达到 1.15 4、1.117、0 .95 76mmol/g  相似文献   
90.
In this study, variations of particulate matter (PM) concentrations in subway trains following installation of platform screen doors (PSDs) in the Seoul subway system were investigated. PM samples were collected in the trains on subway lines 1–8 before and after installation of PSDs. It was found that the mean PM10 concentration in the trains after PSDs installation increased significantly by 29.9% compared to that before installation. In particular, the increase of PM10 in line 6 was the highest at 103%. When the relationship between PM10 and PM2.5 was compared, coefficients of determination (r2) before and after PSDs installations were 0.696 and 0.169, respectively. This suggests that air mixing between the platform and the tunnel after PSDs installation was extremely restricted. In addition, the indoor/outdoor PM10 ratio following PSDs installation increased from 1.32 to 2.97 relative to the period with no installed PSDs. Furthermore, this study revealed that PM levels in subway trains increased significantly after all underground PSDs were put in use. Several potential factors were examined that could result in this PM increase, such as train ventilation systems, operational conditions, passenger volume, subway depth, and the length of underground segments.
ImplicationsPM10 concentrations inside the subway trains increased after PSDs installation. This indicates that air quality in trains was very seriously impacted by PSDs. PM10 levels were also influenced by the tunnel depth and length of the underground segments. To prevent the adverse effect on human health by PM10 emitted from the tunnel, an applicable ventilation system to reduce PM10 is required inside trains and tunnels.  相似文献   
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