Application of artificial neural network approach and remotely sensed imagery for regional eco-environmental quality evaluation

Eco-environment quality evaluation is an important research theme in environment management. In the present study, Fuzhou city in China was selected as a study area and a limited number of 222 sampling field sites were first investigated in situ with the help of a GPS device. Every sampling site was assessed by ecological experts and given an Eco-environment Background Value (EBV) based on a scoring and ranking system. The higher the EBV, the better the ecological environmental quality. Then, three types of eco-environmental attributes that are physically-based and easily-quantifiable at a grid level were extracted: (1) remote sensing derived attributes (vegetation index, wetness index, soil brightness index, surface land temperature index), (2) meteorological attributes (annual temperature and annual precipitation), and (3) terrain attribute (elevation). A Back Propagation (BP) Artificial Neural Network (ANN) model was proposed for the EBV validation and prediction. A three-layer BP ANN model was designed to automatically learn the internal relationship using a training set of known EBV and eco-environmental attributes, followed by the application of the model for predicting EBV values across the whole study area. It was found that the performance of the BP ANN model was satisfactory and capable of an overall prediction accuracy of 82.4%, with a Kappa coefficient of 0.801 in the validation. The evaluation results showed that the eco-environmental quality of Fuzhou city is considered as satisfactory. Through analyzing the spatial correlation between the eco-environmental quality and land uses, it was found that the best eco-environmental areas were related to forest lands, whereas the urban area had the relatively worst eco-environmental quality. Human activities are still considered as a major impact on the eco-environmental quality in this area.     

废矿堆中黄铁矿氧化控制新技术--有机盐包膜法

于３０℃时研究了有机盐包膜对湿润和干燥条件下经接氧化亚铁矿杆菌的黄铁矿氧化的控制作用,湿润下经有机盐包膜的矿石样品的氧化程度与对照相比下降了９７．８％;直接添加有机盐的下降了９６．４％,两种淋洗收集液中有关元素的浓度经ＩＣＰ测定明显低于对照。干燥下微生物未能发挥对黄铁矿的氧化作用,但经包膜后的样品与对照相比,氧化程度又下降了７５．２％,这些结果表明,有机盐包膜既有明显的抑制黄铁矿的化学氧化作用,又     

生物过滤技术在大气污染控制中的应用

生物过滤是控制大气污染的经济有效技术,具有较好的发展前景。本文介绍了生物过滤技术处理废气的研究,应用历史,现状,和生物过滤理论,分析了工艺的使用范围,设计及运行控制要点,列举了应用的范例。     

醇胺溶液吸收与解吸CO2的研究

在温度333K、常压条件下,在羟乙基乙二胺(AEE)总量一定的溶液中,研究了不同浓度AEE对CO2的吸收性能;在总胺质量分数为40%的溶液中,研究了不同配比的AEE N-甲基二乙醇胺(MDEA)对CO2的吸收性能.考察了吸收过程中吸收速率、吸收量、吸收时间、AEE浓度以及吸收液温度的相互关系.控制解吸过程温度为393K,考察了CO2解吸量与解吸时间的关系.实验表明,适当降低AEE浓度有利于充分发挥AEE溶液的CO2吸收性能;在MDEA溶液中加入适量AEE,可以明显提高CO2的吸收与解吸性能;其中质量分数为20?E 20%MDEA的复合溶液在CO2吸收与解吸过程中表现出良好的实际操作性.     

不同加碱量下爆破制浆的源强试验研究

为了解爆破制浆的排污情况和废水处理的可行性,以烧碱和石灰作投加药剂,进行了不同加碱量条件下爆破制浆产生源强的试验研究,以确定最佳的加碱量和适宜的黑液提取率.研究表明,在加碱量相同的情况下,采用常规爆破浆样,浆样性能较好;在保持吨粗干浆产生的COD一致时,投加价格低廉的石灰,既能降低生产成本,又便于后续的废水处理;工程调试运行结果表明,控制吨粗干浆的石灰投加量为25～30 kg时,黑液提取率超过80%,最终出水COD<100 mg/L.     

纳滤膜深度处理棉针织品印染废水

采用芳香聚酰胺膜(NF-1#)、复合膜(NF-2#)和聚酰胺复合膜(NF-3#)深度处理棉针织品印染废水,考察了膜分离性能及膜污染情况的影响因素。实验结果表明,在操作压力为0.5MPa、废水温度为25~35℃、废水pH为7的条件下,NF-1#膜处理效果最佳,COD去除率最高,为76.0%~85.0%;脱盐率也最高,达90.0%。膜过滤后浓水送污水厂处理,产水回用于车间生产。操作压力增高、废水温度升高和废水pH增大均导致滤饼层阻力(Rc)和膜过滤过程中的总阻力(Rt)增加,Rc是Rt的主要组成部分,同时也是导致膜透过通量下降的主要因素。     

Economic assessment of the health effects related to particulate matter pollution in 111 Chinese cities by using economic burden of disease analysis

With China's rapid economic development, environmental problems have become more and more serious. Particulate air pollution is terrible in cities with large and dense population. It may lead to adverse health effects and economic costs. In this study, we calculated the health effects of pollution caused by particulate matter with aerodynamic diameters less than 10mum (PM(10)) in 111 Chinese cities in 2004 according to statistical data and epidemiological exposure-response functions. Using economic burden of disease analysis, an economic assessment of these health risks was also presented. In contrast to many previous studies that have examined individual cities, this study covered most large and medium-sized cities in China, which accounted for more than 70% gross domestic product (GDP) of China in 2004. The total economic cost caused by PM(10) pollution was estimated as approximately US$ 29,178.7 million. Mega cities such as Beijing, Shanghai, and Tianjin contribute relatively more to the total costs. The results will help policy makers in formulating more effective countermeasures and increasing public awareness to enhance environmental protection.     

高氮城市生活垃圾渗滤液短程生物脱氮

采用"两级UASB-缺氧-好氧系统"处理高COD与高NH4 -N的城市生活垃圾渗滤液.180天的试验结果表明:UASB1(一级UASB)与UASB2(二级UASB)最大COD去除速率分别为12.5、8.5 kg·m-3·d-1,UASB1的NOx--N的最大去除速率为3.0 kg·m-3·d-1.系统COD去除率为80%～92%,出水COD为800～1500 mg·L-1.原渗滤液的NH 4-N为1100～2000 mg·L-1,A/O工艺的最大NH4 -N去除速率为0.68kg·m-3·d-1;在17～30℃,通过NO-2-N累积率为90%～99%的短程硝化,NH4 -N的去除率在99%左右,出水NH4 -N小于15 mg·L-1.回流处理水和二沉池回流污泥中的NOx--N分别在UASB1和A/O工艺的缺氧段实现完全反硝化,使系统无机氮TIN去除率达80%～92%.同时高效的反硝化为硝化提供了充足的碱度,使A/O工艺pH大于8.5,维持较高的游离氨浓度,结果表明,高游离氨(FA)是导致短程硝化的主要因素.以pH作为控制参数调控A/O工艺的曝气时间,可以有效的抑制亚硝酸盐氧化菌(NOB)的增长,实现种群优化和稳定的短程硝化.     

牛仔布印染污泥组成特征及资源化途径分析

采用浸出-焙烧-化学分析和显微镜观察等手段查明了牛仔布印染污泥主要由纤维碎和浮石矿物组成。分析了牛仔布印染污泥的浸出物特性及模拟渗滤液的组成。渗滤液含Zn、Pb、Cr等重金属,AS、P和NH3-N超过地表水环境质量Ⅳ类水标准,简易填埋会对环境造成二次污染。分析提出了该类污泥的资源化途径,可用作吸附剂、水泥、轻质陶粒和岩棉的原料。