延河水质污染现状分析研究

为了更好地对延河污染进行控制,增加延河水资源的利用率,采用综合污染指数法,对延河5个监测断面的水质指标进行评价,最后确定延河水质的主要污染物、污染物类型及主要污染断面。结果表明,延河水主要污染物为生化需氧量、化学需氧量以及氨氮,延河水质三氮类、有机类污染为中度污染,重金属类和细菌类污染为轻度污染,总体延河水质属有机类污染,延河主要污染断面为石窑村断面。     

郑州市水污染物排放现状及分析研究

随着经济的进步,水污染问题日益凸显,水资源短缺越来越严重,这不仅制约了城市的经济、社会、环境的可持续发展,更是对人体健康造成了威胁,为了解郑州市近年来污染物排放状况及对其原因进行分析,本文对近几年污染物排放量进行调查,结果表明污水排放总量逐渐上升,这与人口增加、工农业需水量增加有关;主要限排物质COD、氨氮的排放量总体呈下降趋势,但个别年份出现突增现象,这可能与政府的环保政策改变及个别工业偷排有关,对此本研究提出相适应的建议.     

辽宁省土壤污染概况及污染防治技术需求

基于对辽宁省土壤环境的总体状况归纳及描述,提出适合城市工业污染场地、大型矿区污染土壤、地下水及污灌区农田污染土壤的修复技术重点及方向建议。文章提出,突破有机物热脱附、重金属固化/稳定化、淋洗、微生物降解、植物萃取、风险削减、农艺调控等关键技术,形成具有自主知识产权的集成技术体系,建立土壤环境监管大数据平台,对辽宁及东北地区的污染场地/土壤治理具有重要意义。     

Specific antibody for pesticide residue determination produced by antibody-pesticide complex

A new method for specific antibody production was developed using antibody (Ab)-pesticide complex as a unique immunogen. Parathion (PA) was the targeted pesticide, and rabbit polyclonal antibody (Pab) and mouse monoclonal antibody (Mab) were used as carrier proteins. The Ab-PA complexes were generated by conjugating the two antibodies with an excessive dosage of PA. It was shown that the sensitivity of homologous enzyme-linked immunosorbent assay (ELISA) using the new antibodies was similar to that using original antibodies. However, the new mouse Pab had not only similar positive recognizing spectrum as the original Mab, but also a significantly improved sensitivity in heterologous ELISA when some recognizable competitors were applied. IC₅₀ value of ELISA based on a combination of the new mouse Pab and hapten 9 was 0.24 ng/mL, which was 445.54 times as that of the homologous ELISA. An Ab-pesticide complex may be a suitable alternative immunogen for producing highly specific antibody to improve the immunoassay sensitivity.     

g-C3N4制备及其协同PDS可见光催化降解布洛芬的研究

以尿素为主要原料,采用热聚合法在不同条件下制备了光催化剂g-C3N4(石墨相碳化氮),通过改变尿素在马弗炉中加热的温度(350℃、400℃、450℃、500℃)和时间(0.5 h、1 h、1.5 h),得到不同烧结温度和时间的光催化剂,并对其进行X射线衍射(XRD)、扫描电子显微镜(SEM)、傅立叶红外光谱分析仪(FT-IR)、紫外可见漫反射光(UV-Vis)表征,并通过可见光光催化降解布洛芬试验,探究了制备温度、时间对g-C3N4光催化性能的影响;并在溶液中加入PDS(过硫酸钾),联合g-C3N4在可见光下光催化降解布洛芬。结果表明,当烧结温度为500℃、烧结时间为1.5 h时,制备的g-C3N4在可见光区有较强吸收且具有较大的比表面积,以致其表现出最佳的光催化性能;PDS的存在对布洛芬的降解有促进作用,且加快了g-C3N4对布洛芬的光催化降解,相比于纯g-C3N4,4 h内布洛芬的降解率由63%提升为90.5%。以异丙醇、甲醇、对苯醌、草酸钠、重铬酸钾、甲醇分别为羟基自由基(·OH)、·OH和硫酸根自由基(SO4^-·)、超氧自由基(·O2-)、空穴(h+)、电子(e^-)的捕获剂。通过对反应过程的活性物种鉴定,·OH、SO4^-·、h+、e^-均参与了布洛芬的光催化降解,其中h+在反应中的贡献率达到了82.9%,在降解布洛芬过程中起主导作用;在反应体系中添加PDS后,催化剂g-C3N4的荧光强度变小,即加入PDS能够有效降低g-C3N4的光生空穴与电子的复合率,提高g-C3N4的光催化性能。     

Plot-scale spatiotemporal variations of CO2 concentration and flux across water–air interfaces at aquaculture shrimp ponds in a subtropical estuary

Human activities have increased anthropogenic CO₂ emissions, which are believed to play important roles in global warming. The spatiotemporal variations of CO₂ concentration and flux at fine spatial scales in aquaculture ponds remain unclear, particularly in China, the country with the largest aquaculture. In this study, the plot-scale spatiotemporal variations of water CO₂ concentration and flux, both within and among ponds, were researched in shrimp ponds in Shanyutan Wetland, Min River Estuary, Southeast China. The average water CO₂ concentration and flux across the water–air interface in the shrimp ponds over the shrimp farming period varied from 22.79?±?0.54 to 186.66?±?8.71 μmol L^?1 and from ??0.50?±?0.04 to 2.87?±?0.78 mol m^?2 day^?1, respectively. There was no remarkable difference in CO₂ concentration and flux within the ponds, but significantly spatiotemporal differences in CO₂ flux were observed between shrimp ponds. Chlorophyll a, pH, salinity, air temperature, and morphometry were the important factors driving the spatiotemporal patterns of CO₂ flux in the shrimp ponds. Our findings highlighted the importance and spatiotemporal variations of CO₂ flux in the important coastal ecosystems.

     

Removal of rhodamine B from aqueous solution by BiPO4 hierarchical architecture

Hexahedron-like BiPO₄ microcrystals were sucessfully synthesized via a template-free hydrothermal method. The resulting samples were characterized by Xray diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and UV-vis spectroscopy. The BiPO₄ samples were of pure monoclinic phase, and the initial amount of PO_3–4 during synthesis did not show obvious effect on the phase properties of the materials. The hexahedron-like BiPO₄ microcrystal had explicitly cut edges, and its thickness was about 1 μm. The photocatalytic performance of the BiPO₄ catalysts was evaluated by photodegradation of RhB under UV light irradiation with commerial Degussa P25 TiO₂ as reference. Compared with P25, the BiPO₄ catalysts displayed higher photocatalytic activity, with 98.7% of RhB degraded during 60-min experiment. Cost evaluation analysis was adopted to describe the energy consumption of the degradation process, and the results suggested the potential application of this material in the field of dye-contaminated wastewater treatment or environmental matrices remediation.     

Impacts of policy related to structural adjustment of agriculture on grain supply in China

China's policy on structural adjustment of its agriculture is an effective instrument for increasing agricultural production and developing the rural economy. The policy interventions used included converting cultivated land from growing grain crops to cash crops and increasing the production of meat, eggs and milk. The impacts of these changes on grain supply between 1998 and 2004 are identified and quantified at national and regional levels. The data on cultivated land diverted to other purposes are presented for the benefit of the decision maker. The paper concludes that the policy had significant impacts on China's grain supply, which declined by 14.4% of the total grain output in 1998. However, nearly 40% of the cultivated land at national level could potentially be converted by 2010. Regional disparities in the extent of the reduction in grain supply and in land conversion are highlighted with reference to different economic conditions and policy directions.     

Population genetics of Crassostrea ariakensis in Asia inferred from microsatellite markers

Crassostrea ariakensis is an important aquacultured oyster species in Asia, its native region. During the past decade, consideration was given to introducing C. ariakensis into Chesapeake Bay, in the United States, to help revive the declining native oyster industry and bolster the local ecosystem. Little is known about the ecology and biology of this species in Asia due to confusion with nomenclature and difficulty in accurately identifying the species of wild populations in their natural environment. Even less research has been done on the population genetics of native populations of C. ariakensis in Asia. We examined the magnitude and pattern of genetic differentiation among 10 wild populations of C. ariakensis from its confirmed distribution range using eight polymorphic microsatellite markers. Results showed a small but significant global θ _ST (0.018), indicating genetic heterogeneity among populations. Eight genetically distinct populations were further distinguished based on population pairwise θ _ST comparisons, including one in Japan, four in China, and three populations along the coast of South Korea. A significant positive association was detected between genetic and geographic distances among populations, suggesting a genetic pattern of isolation by distance. This research represents a novel observation on wild genetic population structuring in a coastal bivalve species along the coast of the northwest Pacific.     

Preparation of hydrogen-rich gas from waste polyurethane foam by steam gasification and catalytic reforming in a two-stage fixed bed reactor

Journal of Material Cycles and Waste Management - The reclamation of waste rigid polyurethane foam (WRPUF) is capable of realizing both circulations of waste and protection of the environment. In...