我国城市水环境产业发展规模和市场容量的SD模型

采用SD方法,建立了城市水环境产业与人口、经济、资源和环境之间相互关系的动态、非线性模型(SDMUWEIC),在不确定分析基础上,预测了未来城市水环境产业的发展规模、市场容量和市场结构.表明城市水环境产业将为建筑、通用机械设备和水处理专用设备等提供广阔的市场,从而促进消费,带动国民经济其他行业的发展.本文还进一步预测了不同城市人口比例和水价增长速度,对城市水环境产业发展的影响.     

典型铝塑厂周边土壤重金属分布特征与健康风险评价

为探究铝塑园区周边土壤重金属污染情况,选取山东省某城市塑料开发区为研究区,按照分层采样方式获取到80个土壤样品,分别测定土壤中As、Cd、Hg、Cr、Cu、Ni、Pb、Zn含量,运用统计分析法探讨土壤重金属等的分布特征和来源,并利用健康风险评价模型确定了土壤重金属对周边居民的健康风险。结果表明:As、Cd、Hg、Cr、Cu、Ni、Pb和Zn均超出山东省土壤背景值,其中Cd、Hg、Cu和Pb分别超出背景值48. 15%、106. 90%、62. 04%和39. 96%,表明土壤中存在一定程度的重金属积累,在周边140～210 m处最为严重,且受人类活动影响强烈,与风向关系不大;土壤重金属垂直分布特征大致呈现随着深度的增加不断增加,在20 cm深度附近达到最高值,其后不断降低并趋于平稳,Cd、Hg、Cu、Pb和Zn变异幅度大,受到人为干扰较大,As、Cr和Ni主要受成土母质控制,属于自然来源,变动幅度较小;研究区内8种元素不存在非致癌风险,Cr、As、Ni和Cd产生的致癌风险处在可接受范围内,但存在的潜在致癌风险应引起足够的重视。     

Will urban expansion lead to an increase in future water pollution loads?—a preliminary investigation of the Haihe River Basin in northeastern China

Urban expansion is a major driving force changing regional hydrology and nonpoint source pollution. The Haihe River Basin, the political, economic, and cultural center of northeastern China, has undergone rapid urbanization in recent decades. To investigate the consequences of future urban sprawl on nonpoint source water pollutant emissions in the river basin, the urban sprawl in 2030 was estimated, and the annual runoff and nonpoint source pollution in the Haihe River basin were simulated. The Integrated Model of Non-Point Sources Pollution Processes (IMPULSE) was used to simulate the effects of urban sprawl on nonpoint source pollution emissions. The outcomes indicated that the urban expansion through 2030 increased the nonpoint source total nitrogen (TN), total phosphorous (TP), and chemical oxygen demand (COD) emissions by 8.08, 0.14, and 149.57 kg/km², respectively. Compared to 2008, the total nonpoint emissions rose by 15.33, 0.57, and 12.39 %, respectively. Twelve percent of the 25 cities in the basin would increase by more than 50 % in nonpoint source TN and COD emissions in 2030. In particular, the nonpoint source TN emissions in Xinxiang, Jiaozuo, and Puyang would rise by 73.31, 67.25, and 58.61 %, and the nonpoint source COD emissions in these cities would rise by 74.02, 51.99, and 53.27 %, respectively. The point source pollution emissions in 2008 and 2030 were also estimated to explore the effects of urban sprawl on total water pollution loads. Urban sprawl through 2030 would bring significant structural changes of total TN, TP, and COD emissions for each city in the area. The results of this study could provide insights into the effects of urbanization in the study area and the methods could help to recognize the role that future urban sprawl plays in the total water pollution loads in the water quality management process.     

Molecular diversity of arbuscular mycorrhizal fungi at a large-scale antimony mining area in southern China

Arbuscular mycorrhizal fungi (AMF) have great potential for assisting heavy metal hyperaccumulators in the remediation of contaminated soils. However, little information is available about the community composition of AMF under natural conditions in soils contaminated by antimony (Sb). The objective of this study was to investigate the characteristics of AMF molecular diversity, and to explore the effects of Sb content and soil properties on the AMF community structure in an Sb mining area. Four Sb mine spoils and one adjacent reference area were selected from around the Xikuangshan mine in southern China. The association of AMF molecular diversity and community composition with the rhizosphere soils of the dominant plant species was studied by Polymerase Chain Reaction-Denaturing Gradient Gel Electrophoresis (PCR-DGGE). Results from all five studied sites showed that the diversity of AMF decreased with increasing Sb concentration. Principal component analysis (PCA) indicated that the AMF community structure was markedly different among these groups. Further redundancy analysis (RDA) showed that Sb contamination was the dominating factor influencing the AMF community structure in the Sb mine area. However, the multivariate analysis showed that, apart from the soil Sb content, extractable nitrogen content and organic matter content also attributed to AMF sequence distribution type. Some AMF sequences were only found in the highly contaminated area and these might be ideal candidates for improving phytoremediation efficiency in Sb mining regions. Gene sequencing analysis revealed that most species were affiliated with Glomus, suggesting that Glomus was the dominant AMF genus in the studied Sb mining area.     

硫丹及硫丹硫酸酯的土壤降解特性

在实验室条件下研究了α-硫丹、β-硫丹及硫丹硫酸酯在东北黑壤土、江苏水稻土、江西红壤土和河南二合土4种土壤中的降解特性.结果表明,硫丹及硫丹硫酸酯降解过程可用一级动力学方程描述.4种土壤中,β-硫丹的降解半衰期(DT50)分别为39、10、14和13d;α-硫丹的DT50分别为72、56、105和42d;硫丹硫酸酯的DT50分别为39、41、53和34d,因此,硫丹硫酸酯在土壤中的持久性值得关注.α-硫丹在有机质含量丰富的土壤中降解较慢,β-硫丹在碱性土壤中降解较快.用一级动力学模型模拟的硫丹(α-硫丹+β-硫丹)和总硫丹(α-硫丹+β-硫丹+硫丹硫酸酯)降解过程的计算结果表明,硫丹的DT50为18～47d,总硫丹的DT50为48～77d.试验观察到的硫丹降解产物依次为硫丹硫酸酯、硫丹二醇、硫丹醚和硫丹羟基醚.     

丝绸之路甘肃段汉代村落遗址空间分布及其影响因素 【封面文章】

运用历史文献分析法和GIS空间分析法对丝绸之路甘肃段汉代村落遗址空间分布及其影响因素复原与认识,并引入地理探测器进行单因子分析以更准确地探求各影响因子对村落遗址空间分布决定程度,进一步揭示区域内自然环境要素与人类自身活动之间的关系。结果表明：（1）该段392处汉代村落遗址总体呈现“大分散、小集聚”空间分布格局,且形成若干分布核心区。其中,今金塔县东沙窝一带是研究区域内村落遗址空间集聚度最高地区,密度可达3.036处∙ (100km²)⁻¹;（2）从微观层面看,村落遗址面积规模和文化层厚度数量均有较为明显的等级分布特点,大体呈“金字塔”型,且研究区域东、西部之间受地形地貌、生产方式、历史文化等影响存在一定差异性;（3）村落遗址濒水特征显著,且多分布在坡度＜3°的黄土台地、丘陵及冲积平原、绿洲上。水源因子解释力远大于其他各因子,权重占比达28.80%,中心城邑、道路交通依次次之。水源是影响该区域村落遗址空间分布的主导因素。同时,不晚于汉代村落选址布局虽仍受水源等自然环境因素制约,人文社会诸要素对村落形成发展的影响作用却也日益凸显。     

南京地区PCB52多介质迁移归趋行为模拟及环境风险评价

运用多介质逸度模型对PCB52在南京地区空气、水体、土壤和沉积物中的浓度分布与多介质间的迁移、归趋行为进行模拟研究并分析PCB52在研究区域环境多介质间的迁移通量,确定其在环境中的主要迁移过程;结合文献中的监测数据,对模型的可靠性进行验证;对模型的输入参数进行灵敏度分析;通过模拟浓度与实际浓度的对比,表明模型在该地区具有很好的适用性。结果表明,环境系统达到平衡时,PCB52在沉积物中的含量占其在环境系统总含量的96.12%;PCB52从环境系统中的消失途径主要为空气平流输出和空气降解;环境温度和空气平流输入是影响化合物在环境相中浓度分布的最主要因素。此外,PCB52初步的生态风险评价表明其对生态环境未构成严重威胁,但潜在危害仍不容忽视。     

7种酚类化学物质对活性污泥的呼吸抑制作用

苯酚类化学物质是废水中常见的有机污染物,其对活性污泥的毒性数据对于污水处理厂稳定运行和化学品危害性评估具有重要意义。本研究采用活性污泥呼吸抑制试验(209)测定7种酚类化学物质对活性污泥的呼吸抑制作用。结果显示,2,6-二叔丁基苯酚和对特辛基苯酚对活性污泥未产生明显的毒性效应;2,4-二氯酚、2-苯基苯酚、4-硝基酚、4-氯酚和对甲酚等5种化学物质都对活性污泥呼吸有不同程度的抑制效应,3 h-EC50值分别为49.7、77.6、102、150.1和462 mg·L-1,构效关系分析结果表明-Cl、-NO2等官能团是导致活性污泥呼吸抑制效应增强的关键因素。在化学品生物降解性测试研究中,要确保有毒化学物质的测试浓度低于EC50值的1/10。     

Water quality monitoring in a slightly-polluted inland water body through remote sensing — Case study of the Guanting Reservoir in Beijing, China

This study focused on the water quality of the Guanting Reservoir, a possible auxiliary drinking water source for Beijing. Through a remote sensing (RS) approach and using Landsat 5 Thematic Mapper (TM) data, water quality retrieval models were established and analyzed for eight common water quality variables, including algae content, turbidity, and concentrations of chemical oxygen demand, total nitrogen, ammonia nitrogen, nitrate nitrogen, total phosphorus, and dissolved phosphorus. The results show that there exists a statistically significant correlation between each water quality variable and remote sensing data in a slightly-polluted inland water body with fairly weak spectral radiation. With an appropriate method of sampling pixel digital numbers and multiple regression algorithms, retrieval of the algae content, turbidity, and nitrate nitrogen concentration was achieved within 10% mean relative error, concentrations of total nitrogen and dissolved phosphorus within 20%, and concentrations of ammonia nitrogen and total phosphorus within 30%. On the other hand, no effective retrieval method for chemical oxygen demand was found. These accuracies were acceptable for the practical application of routine monitoring and early warning on water quality safety with the support of precise traditional monitoring. The results show that performing the most traditional routine monitoring of water quality by RS in relatively clean inland water bodies is possible and effective.     

Post-evaluation of a water pollution control plan: methodology and case study

China has developed more than 20 water pollution control plans for river basins (RBWPs) since 1996. However, the implementation has generally lagged. This paper proposes a three-step, post-evaluation methodology to analyze the implementation result of a RBWP and its influential factors. First, a multi-attribute evaluation method based on an index system is established to score the enforcement results of a RBWP. Indicators measure how well a RBWP has achieved its objectives, which include water quality compliance, pollution load control, project construction, financial inputs, and related management requirements. Second, an interpretive structural model is used to detect the significant factors that affect RBWP implementation. This model can effectively analyze the cause-effect chain and hierarchical relationship among variables. Five groups of factors were identified, namely, plan preparation, water resource endowment, policy, institution, and management. Both qualitative and quantitative methods are employed in the third step to evaluate the extent to which these factors have influenced the execution result of a RBWP, including pre-post contrast, scenario analysis, and correlation analysis. This research then post-evaluated the implementation of the Huai River Basin water pollution control plans (H-RBWPs) over a period of 10 years as a case study. Results showed that the implementation of the H-RBWPs was unsatisfactory during 2001–2005, although it improved during 2006–2010. The poor execution of these plans was partially caused by the underestimation of regional economic development in combination with ineffective industrial structure adjustment policies. Therefore, this case study demonstrates the feasibility and flexibility of the proposed post-evaluation methodology.