A system dynamics approach for regional environmental planning and management: a study for the Lake Erhai Basin

In recent years, water-quality deterioration associated with rapid socio-economic development in the Lake Erhai Basin, China, has acquired more and more attention from the public and the government. An effective planning for the basin's environmental management system is desired for sustainable regional development. In this study, an environmental system dynamics model, named ErhaiSD, is developed for supporting this planning task. The ErhaiSD consists of dynamic simulation models that explicitly consider information feedback that governs interactions in the system. Such models are capable of synthesizing component-level knowledge into system behaviour simulation at an integrated level. This capability is very useful in analyzing and recommending policy decisions. For the study case, interactions among a umber of system components within a time frame of 15 years are examined dynamically. Four planning alternatives are considered. The base run is based on an assumption that the existing pattern of human activities will prevail in the entire planning horizon, and the other alternatives are based on previous planning studies. The contributions of various nonpoint pollution sources to the lake's eutrophication problems, and the effects of industrial activities and wastewater treatment processes on pollution problems in the Xier River are analyzed through the developed modeling system. The exercise draws attention to the implications of different alternatives to the system's environmental and socio-economic objectives. The modeling results are directly useful for simulating and evaluating a variety of decision actions and their dynamic consequences, and answering questions such as 'What should I do?', 'What if I do?' and 'What are the expected consequences?'.     

常州市典型工业废水综合急性毒性评估

以不同营养级别的藻(生产者)、溞(消费者)和发光细菌(分解者)为指示生物,在发光细菌急性毒性、大型溞急性毒性和叶绿素荧光急性毒性实验这三者的基础上,采用毒性分级体系(toxicity classification system)对常州市六种典型企业原水和处理出水的综合急性毒性进行了评估及比较。结果表明,六种典型企业原水都具有明显的急性毒性,电镀厂、食品厂和综合污水处理厂的处理出水基本无毒,毒性削减明显,但化工厂、印染厂和电子厂处理出水具有较高的急性毒性,而理化指标监测结果表明这六种处理出水可以直接排放。废水综合急性毒性大小和理化指标结果没有必然联系,应进一步完善理化监测指标,强制性增加生物毒性指标的监测。     

城市生活垃圾卫生填埋场工艺设计及存在问题探讨

推广城市生活垃圾卫生填埋技术是迅速提高我国垃圾无害化处理率的有效办法。根据青铜峡市地理、水文等环境条件,以及该市垃圾组成成分的特点,设计了垃圾卫生填埋场的防渗处理系统,渗沥液收集处理系统和废气收集系统,并对设计中发现的问题进行分析,提出相应的建议,以期为类似地区、条件下垃圾卫生填埋场的设计和建设提供借鉴。     

Organochlorine pesticides (DDTs and HCHs) in soils from the outskirts of Beijing, China

Concentrations of HCH (hexachlorocyclohexane) and DDT (Dichlorodiphenyltrichloroethane) were determined in shallow subsurface (5-30 cm depth) and deep soil layers (150-180 cm depth) from the outskirts of Beijing, China. Concentrations of total HCHs (including alpha, beta, gamma, delta-isomers) and total DDTs (including p,p'-DDT, p,p'-DDE, p,p'-DDD, o,p'-DDT) in shallow subsurface soils ranged from 1.36 to 56.61 ng/g dw (median 5.25 ng/g), and from 0.77 to 2178 ng/g (median 38.66 ng/g), respectively, and those in the deeper layers were approximately an order of magnitude less. The spatial distribution of HCHs and DDTs reflected the known historical usage of these pesticides. No correlation between the concentrations of pesticides and soil organic matter content or clay content can be found. The factors affecting residue levels and compositions of DDT and HCH were discussed. The contour maps of beta/gamma ratios and DDT/DDE ratios for both the shallow subsurface and deep layer soils were drawn.     

土壤和沉积物的有机质组分对水中非离子有机物吸着的影响

在２５℃下，分别测定来自水各地的四种土壤和八种沉积物吸着水溶液中的１，２－二氯苯和四氯化碳的吸附等温线，所有的等温线呈线性，表明土壤和沉积物吸着水溶液中的非离子有机物的过程是分配机理，土壤或沉物的本身用有机碳标化的吸附系数（Ｋｏｃ）之间差异不大，而土壤的和沉积物之间的Ｋｏｃ则存在显著性差异，这是由于沉积物有机质成分的极性小于土壤有机质成分的极性造成的，沉积物质吸着上述两种有机物的Ｋｏｃ约是土壤的Ｋ     

基于小波变换的ARIMA模型在水质预测中的应用研究

近年来,黑龙江黑河流域的水质状况逐年恶化,而溶解氧(DO)是研究水体自净能力和污染程度的一个重要指标。通过收集该地区2010年48周的DO浓度数据,经由小波变换对数据进行高频和低频的分离,再分别建立ARIMA模型,由此预测未来5期的DO浓度值的变化。结果表明,该模型较好地反映了DO浓度值的变化趋势,预测精度更高,同时,反映出DO浓度值随季节的变化规律,以期为该地区的水质分析预测和水体保护工作提供参考。     

广州市夏、冬季室内外PM2.5质量浓度的特征

2004年7月2日至8月13日和2004年11月29日至2005年1月6日分别在广州市3种类型区域(一般城市区域、道路旁、工业源附近)9个居民住宅的室内和室外同步采集了PM2.5颗粒.采用标准称重法测定PM2.5质量浓度,得到广州市夏季住宅室内外PM2.5平均质量浓度分别为67.7、74.5 μg/m3,冬季室内外PM2.5平均质量浓度分别为109.9、123.7 μg/m3.广州市PM2.5平均质量浓度,与美国PM2.5标准相比,与国内PM10标准基础上假设的PM2.5限值相比,与其他一些国内、亚洲和欧美城市的文献记录相比,结果均显示广州市PM2.5处于相当严重污染状态.广州市PM2.5质量浓度呈现明显的空间分布特征和季节变化特征;PM2.5室内质量浓度并不总是低于室外质量浓度,反映了室内空气污染的存在.     

太湖水源地水体中半挥发性有机物的监测

太湖某水源地水样经C18柱富集、气相色谱-质谱法(GC-MS)分离,定性测定其中的有机物.在丰水期、平水期、枯水期分别采样,在检测到的近百种有机化合物中有40种出现频率很高,同时运用内标法对其进行相对含量的比较,结果表明脂肪族化合物、邻苯二甲酸酯、2,6-二叔丁基-4-甲基苯酚和异氰尿酸三甲酯的相对含量较高,值得引起关注.     

Ambient halocarbon mixing ratios in 45 Chinese cities

During this study 158 whole air samples were collected in 45 Chinese cities in January and February 2001. The spatial distribution of different classes of halocarbons in the Chinese urban atmosphere, including chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), Halon-1211, and other chlorinated compounds is presented and discussed. Most of these compounds were enhanced compared to background levels. However, the mean enhancement of CFCs was relatively small, with CFC-12 and CFC-11 increases of 6% (range 1–31%) and 10% (range 2–89%), respectively, with respect to the global background. On the contrary, strongly enhanced levels of CFC replacement compounds and halogenated compounds used as solvents were measured. The average Halon-1211 concentration exceeded the background of 4.3 pptv by 75% and was higher than 10 pptv in several cities. Methyl chloride mixing ratios were also strongly elevated (78% higher than background levels), which is likely related to the widespread use of coal and biofuel in China.