Land use pattern, socio-economic development, and assessment of their impacts on ecosystem service value: study on natural wetlands distribution area (NWDA) in Fuzhou city, southeastern China

This paper quantifies the allocation of ecosystem services value (ESV) associated with land use pattern and qualitatively examined impacts of land use changes and socio-economic factors on spatiotemporal variation of ESV in the Natural Wetland Distribution Area (NWDA), Fuzhou city, China. The results showed that total ESV of the study area decreased from 4,332.16?×?10⁶ RMB Yuan in 1989 to 3,697.42?×?10⁶ RMB Yuan in 2009, mainly due to the remarkable decreases in cropland (decreased by 55.3 %) and wetland (decreased by 74.2 %). Forest, water, and wetland played major roles in providing ecosystem services, accounting for over 90 % of the total ESV. Based on time series Landsat TM/ETM+ imagery, geographic information system, and historical data, analysis of the spatiotemporal variation of ESV from 1989 to 2009 was performed. It indicated that rapid expansion of urban areas along the Minjiang River resulted in significant changes in land use types, leading to a dramatic decline in ecosystem services. Meanwhile, because of land scarcity and unique ecosystem functions, the emergency of wetland and cropland protection in built-up area has become an urgent task of local authorities to the local government. Furthermore, there was still a significant negative correlation between ESV of cropland and wetland and the GDP. The results suggest that future planning of land use pattern should control encroachment of urban areas into cropland and wetland in addition to scientific and rational policies towards minimizing the adverse effects of urbanization.     

Mercury concentration in the muscle of seven fish species from Chagan Lake,Northeast China

Chagan Lake is located downstream of the Second Songhua River basin in Northeast China. It is one of the top ten inland freshwater lakes, and an important aquatic farm in China. The lake has been receiving large amounts (currently at 1.5 × 10⁸ m³/a) of water from the river since 1984. This would pose a threat to the aquatic system of the lake because the river was seriously polluted with mercury in 1970s–1980s. The current study is the first to report the total mercury concentrations in fish found in the lake. Mercury concentrations in seven fish species collected from the lake in January 2009 were determined. The related human health risk from fish consumption was also assessed. The average concentration of mercury in the fish was 18.8 μg/kg of wet weight, ranging from 4.5 to 37.6 μg/kg of wet weight. A large difference in the mercury concentrations among the fish species was found. The mercury concentration was found to be higher in carnivorous species and lower in omnivorous and herbivorous species. This demonstrates greater mercury bioaccumulation in fish species at higher trophic levels. Mercury concentrations in fish showed significant positive correlations with age, length, and weight. No significant relationship was found between mercury concentrations in fish and the habitat preferences. Mercury concentrations in fish from the lake were within the limits of the international and national standards of China established for mercury. According to the reference doses established by the United States Environmental Protection Agency, the maximum safe consuming quantity considering all the fish was 297.3 g/day/person, which was more than five times as much as the current quantity (50 g/day/person) consumed by the local residents. This investigation indicates that the historical pollution of the Second Songhua River has not caused mercury bioaccumulation in fish muscle tissue of Chagan Lake. The present consumption of fish from the lake in the local area does not pose a threat to human health.     

北方沙尘对四川盆地环境空气质量影响和特征分析

利用沙尘天气资料和颗粒物浓度、激光雷达监测数据以及后向轨迹,分析浮尘天气的气象特征及传输路径,构建了浮尘天气对四川盆地各城市大气环境质量影响的量化指标,并利用该量化指标分析了浮尘天气对四川盆地各城市大气环境的影响,得出2013—2015年浮尘对四川盆地PM_(10)年均质量浓度的贡献,2013—2015年约为4.82、1.00、0.56μg/m~3;浮尘对PM_(10)年均质量浓度的贡献川西区域最大,川东北区域次之,川中区域最小,其贡献量分别为3.5、2.2、1.4μg/m~3。同时还进一步分析浮尘对区域PM_(10)影响差异的原因。     

Natural and anthropogenic factors affecting the shallow groundwater quality in a typical irrigation area with reclaimed water,North China Plain

In this study, the hydrochemical characteristics of shallow groundwater were analyzed to get insight into the factors affecting groundwater quality in a typical agricultural dominated area of the North China Plain. Forty-four shallow groundwater samples were collected for chemical analysis. The water type changes from Ca·Na-HCO₃ type in grass land to Ca·Na-Cl (+NO₃) type and Na (Ca)-Cl (+NO₃+SO₄) type in construction and facility agricultural land, indicating the influence of human activities. The factor analysis and geostatistical analysis revealed that the two major factors contributing to the groundwater hydrochemical compositions were the water-rock interaction and contamination from sewage discharge and agricultural fertilizers. The major ions (F, HCO₃) and trace element (As) in the shallow groundwater represented the natural origin, while the nitrate and sulfate concentrations were related to the application of fertilizer and sewage discharge in the facility agricultural area, which was mainly affected by the human activities. The values of pH, total dissolved solids, electric conductivity, and conventional component (K, Ca, Na, Mg, Cl) in shallow groundwater increased from grass land and cultivated land, to construction land and to facility agriculture which were originated from the combination sources of natural processes (e.g., water-rock interaction) and human activities (e.g., domestic effluents). The study indicated that both natural processes and human activities had influences on the groundwater hydrochemical compositions in shallow groundwater, while anthropogenic processes had more contribution, especially in the reclaimed water irrigation area.     

巢湖南淝河河口底泥污染特征及疏浚决策

为了解巢湖南淝河河口区域底泥污染特征,为底泥疏浚提供决策依据,对该区域底泥中营养物、重金属含量及释放特征进行分析,并采用有机指数法、污染指数法及潜在生态风险评价对底泥的污染状况进行评估.结果表明,调查区域总氮(TN)、总磷(TP)以及有机质(OM)的均值为1 461 mg·kg-1、438 mg·kg-1和1.77％,...     

溶液中阴离子和腐殖酸对UV/H2O2降解2,4-二氯酚的影响

研究了UV/H2O2工艺对2,4-二氯酚(2,4-DCP)的去除效果和水中阴离子、腐殖酸对该工艺降解2,4-DCP的影响.结果表明:UV/H2O2工艺可以有效地去除水中2,4-DCP,光降解过程符合一级反应动力学模型;在H2O2投加量为8 mg/L、1个30 W低压汞灯照射下,2,4-DCP在蒸馏水和自来水中反应速率常数分别为0.023 2、0.016 2 min-1;NO-3、Cl-、HCO-3对2,4-DCP光降解有抑制作用,当3种阴离子摩尔浓度为0.5、10.0、20.0 mmol/L时,对2,4-DCP光降解的抑制程度为HCO-3＞NO-3＞Cl-;腐殖酸在低浓度时,促进光降解反应进行,在高浓度时,2,4-DCP的光降解受到抑制.自来水中的反应速率常数低于蒸馏水中的反应速率常数是由于水中多种阴离子和腐殖酸影响的结果.     

医疗废物无害化处置工艺设计

采取AB型热解两次焚烧(3T控制)和烟气净化处理新技术进行医疗废物无害化处置工艺设计,运行结果表明:该工艺技术能有效地处理医疗废物,具有无二次污染和社会、经济、环境效益好等优点,值得在实践中进一步推广应用。     

多组学技术应用于化学品风险评估的研究进展

随着进入到环境中的化学品种类和数量日益增加,化学品风险评估面临着越来越大的挑战.传统的化学品风险评估方法依赖于动物实验,无法对大量化学品的毒性进行高效检验与预测,并且缺少对机制的研究.多组学技术是多种高通量组学技术的联合应用,主要包括基因组学、转录组学、蛋白质组学和代谢组学等,可以更加快速、准确地分析化学品毒性,预测化...     

西南喀斯特地区典型矿渣中砷、锑的赋存形态及其潜在风险评价

针对西南喀斯特地区典型矿渣中砷、锑的赋存形态及其潜在风险的问题,采用Shiowatana连续提取法提取矿渣中的砷（As）、锑（Sb）,分析并揭示As、Sb的赋存特征;结合矿渣的基本理化性质和矿物组成特征,讨论矿渣堆中As、Sb的活动性及其关键影响因素;采用风险评价编码法（RAC）对矿渣中As、Sb的潜在生态风险进行相关评价.结果表明：矿渣中的As主要以铁铝结合态和残渣态的形式赋存;Sb主要以残渣态的形式赋存.As比Sb具有更高比例的铁铝结合态,而Sb比As具有更高比例的碳酸盐结合态.弱酸至近中性矿渣中,Sb的活动性强于As;酸性矿渣中,As的活动性强于Sb.矿渣中As、Sb的潜在风险以中-低风险为主,个别为高和极高风险.     

Biogeochemical transfer and dynamics of iodine in a soil–plant system

Radioactive iodide (¹²⁵I) is used as a tracer to investigate the fate and transport of iodine in soil under various leaching conditions as well as the dynamic transfer in a soil–plant (Chinese cabbage) system. Results show that both soils (the paddy soil and the sandy soil) exhibit strong retention capability, with the paddy soil being slightly stronger. Most iodine is retained by soils, especially in the top 10 cm, and the highest concentration occurs at the top most section of the soil columns. Leaching with 1–2 pore volume water does not change this pattern of vertical distributions. Early breakthrough and long tailing are two features observed in the leaching experiments. Because of the relatively low peak concentration, the early breakthrough is really not an environmental concern of contamination to groundwater. The long tailing implies that the retained iodine is undergoing slow but steady release and the soils can provide a low but stable level of mobile iodine after a short period. The enrichment factors of ¹²⁵I in different plant tissues are ranked as: root > stem > petiole > leaf, and the ¹²⁵I distribution in the young leaves is obviously higher than that in the old ones. The concentrations of ¹²⁵I in soil and Chinese cabbage can be simulated with a dual-chamber model very well. The biogeochemical behaviors of iodine in the soil-cabbage system show that cultivating iodized cabbage is an environmentally friendly and effective technique to eliminate iodine deficiency disorders (IDD). Planting vegetables such as cabbage on the ¹²⁹I-contaminated soil could be a good remediation technique worthy of consideration.