基于污染物总量控制的流域预警体系构建研究

文章通过对中国目前水环境质量现状分析,指出流域环境预警体系建立的必要性,并选择总量控制指标作为预警体系的评价指标。利用层次分析法建立基于污染物总量控制的流域预警体系,确定预警因子的权重和评分标准,设立临界状态,不良状态预警、缓慢恶化预警和迅速恶化预警4个级别,为建立流域环境质量预警体系提供借鉴。     

桂林大气降水化学特征及其经树木枝叶淋滤后的变化

大气降水经过茂密的树木枝叶后,其化学成分含量会发生改变,本文通过于2011年4、5月份在桂林理工大学校园内接收未经植被淋滤的普通雨水和经过铁树、桂花树、竹子3种树木枝叶淋滤的雨水,测定其K＋、Na＋、Mg＋、Ca2＋、SO24-、Cl-、PO34-和TN的含量,分析其基本特征和变化规律。大气降水在经过以上3种树木枝叶淋滤后,其总氮含量及各种离子含量和未经树木淋滤的普通雨水相比都是增加的。由于各种综合因素影响,其变化规律呈多样性。     

Synthesis and adsorption performance of lead ion-imprinted micro-beads with combination of two functional monomers

Synthesis and high adsorption and selectivity performance of lead ion-imprinted micro-beads with combination of two functional monomers.     

Effect of ferric and bromide ions on the formation and speciation of disinfection byproducts during chlorination

The e ects of ferric ion, pH, and bromide on the formation and distribution of disinfection byproducts (DBPs) during chlorination were studied. Two raw water samples from Huangpu River and Yangtze River, two typical drinking water sources of Shanghai, were used for the investigation. Compared with the samples from Huangpu River, the raw water samples from Yangtze River had lower content of total organic carbon (TOC) and ferric ions, but higher bromide concentrations. Under controlled chlorination conditions, four trihalomethanes (THMs), nine haloacetic acids (HAAs), total organic halogen (TOX) and its halogen species fractions, including total organic chlorine (TOCl) and total organic bromide (TOBr), were determined. The results showed that co-existent ferric and bromide ions significantly promoted the formation of total THMs and HAAs for both raw water samples. Higher concentration of bromide ions significantly changed the speciation of the formed THMs and HAAs. There was an obvious shift to brominated species, which might result in a more adverse influence on the safety of drinking water. The results also indicated that high levels of bromide ions in raw water samples produced higher percentages of unknown TOBr.     

油田含油污泥物性分析

含油污泥一般含油15％-50％,且泥中污油老化严重。而且油泥中原油、泥砂组份比例变化较大,从而影响油泥处理工艺的效果。本研究通过油泥成分分析研究了大庆油田采油八厂含油污泥的特性,并对其影响进行了分析。     

Comparison of Indexes for Prioritizing Placement of Water Quality Buffers in Agricultural Watersheds1

Dosskey, Michael G. and Zeyuan Qiu, 2011. Comparison of Indexes for Prioritizing Placement of Water Quality Buffers in Agricultural Watersheds. Journal of the American Water Resources Association (JAWRA) 47(4):662‐671. DOI: 10.1111/j.1752‐1688.2011.00532.x Abstract: Five physically based, spatially distributed, empirical indexes were compared for the degree to which they identified the same or different locations in watersheds where vegetative buffers would function better for reducing agricultural nonpoint source pollution. All five indexes were calculated on a 10 m × 10 m digital elevation grid on agricultural land in the 144‐km² Neshanic River watershed in New Jersey. The indexes included the topography‐based Wetness Index (WI) and Topographic Index (TI) and three soil survey‐based indexes (sediment trapping efficiency [STE], water trapping efficiency [WTE], and groundwater interaction [GI]). Results showed that each index associated higher pollution risk and mitigation potential to a different part of the landscape. The WI and TI identified swales and riparian areas where runoff converges, whereas STE and WTE identified upland sites. The STE and WTE lack the fine scale of slope resolution and the accounting for convergent runoff patterns that can be important for properly locating buffers in some watersheds. The GI index indicates the existence of a shallow water table but the correspondence with WI‐ and TI‐identified sites was only modest. For watersheds where pollutant loading is generated by both saturation‐excess (emphasized by TI and WI) and infiltration‐excess processes (emphasized by STE and WTE), the indexes could be complementary. However, techniques would be needed for properly apportioning priority among sites identified by each index.     

基于供应链和可拓决策的食品安全预警模型及其应用

为提高食品安全预警能力,改善食品安全状况,以食品原料供应环境质量、生产加工、流通加工、销售食品质量、食品安全管理与监测作为食品安全预警的关键因素,提出一种基于供应链和可拓决策的食品安全预警模型。从供应链的角度建立食品安全预警指标体系,确定食品安全的经典域、节域和预警对象;建立食品安全预警模型并给出食品安全预警的方法和步骤;结合A省2010年的食品安全数据,定量评价A省食品安全预警状态,结合模型评价结果进行单指标和综合安全预警分析,验证该模型的合理性和适用性。研究结果表明:针对食品安全状况与预警特征,运用基于供应链和可拓决策的食品安全预警模型,能够对食品安全状态进行快速判断并有效预警。     

Identification of microcystins contamination in surface water samples from the Three Gorges Reservoir, China

Physicochemical and biological parameters related to water quality and microcystins (MCs) contamination in aquatic environment of the Three Gorges Reservoir were investigated in August 2004 and January 2005. A solid-phase extraction method and an HPLC equipped with photodiode array were used for MC-LR detection. A quantitative analysis showed the total MC-LR concentrations of water samples ranged from non-detectable to 0.57 μg L?1 among the seven sampling sites. The highest MC-LR concentration was found at sampling site G (Wushan), which was followed by F (Kaixian), E (Wanzhou), D (Fuling), C (Cuntan), and A (Daxigou). The correlation analysis showed the MC-LR concentration was positively correlated with chlorophyll-a concentration. This result suggests that MC concentration in water can be indirectly estimated by analyzing the chlorophyll-a concentration. Overall, the results of this study suggest that more importance should be placed on monitoring of MC contamination and water quality in the Three Gorges Reservoir to ensure drinking water safety and reduce the potential exposure of people to these health hazards.     

N-doped CoAl oxides from hydrotalcites with enhanced oxygen vacancies for excellent low-temperature propane oxidation

A series of nitrogen-doped CoAlO (N-CoAlO) were constructed by a hydrothermal route combined with a controllable NH₃ treatment strategy. The effects of NH₃ treatment on the physico-chemical properties and oxidation activities of N-CoAlO catalysts were investigated. In comparison to CoAlO, a smallest content decrease in surface Co³⁺ (serving as active sites) while a largest increased amount of surface Co²⁺ (contributing to oxygen species) are obtained over N-CoAlO/4h among the N-CoAlO catalysts. Meanwhile, a maximum N doping is found over N-CoAlO/4h. As a result, N-CoAlO/4h (under NH₃ treatment at 400°C for 4 hr) with rich oxygen vacancies shows optimal catalytic activity, with a T₉₀ (the temperature required to reach a 90% conversion of propane) at 266°C. The more oxygen vacancies are caused by the co-operative effects of N doping and suitable reduction of Co³⁺ for N-CoAlO/4h, leading to an enhanced oxygen mobility, which in turn promotes C₃H₈ total oxidation activity dominated by Langmuir-Hinshelwood mechanism. Moreover, in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTs) analysis shows that N doping facilities the decomposition of intermediate species (propylene and formate) into CO₂ over the catalyst surface of N-CoAlO/4h more easily. Our reported design in this work will provide a promising way to develop abundant oxygen vacancies of Co-based catalysts derived from hydrotalcites by a simple NH₃ treatment.     

Synergistic cytotoxicity of binary combinations of inorganic and organic disinfection byproducts assessed by real-time cell analysis

Chlorine, chlorine dioxide, and ozone are widely used as disinfectants in drinking water treatments. However, the combined use of different disinfectants can result in the formation of various organic and inorganic disinfection byproducts (DBPs). The toxic interactions, including synergism, addition, and antagonism, among the complex DBPs are still unclear. In this study, we established and verified a real-time cell analysis (RTCA) method for cytotoxicity measurement on Chinese hamster ovary (CHO) cell. Using this convenient and accurate method, we assessed the cytotoxicity of a series of binary combinations consisting of one of the 3 inorganic DBPs (chlorite, chlorate, and bromate) and one of the 32 regulated and emerging organic DBPs. The combination index (CI) of each combination was calculated and evaluated by isobolographic analysis to reflect the toxic interactions. The results confirmed the synergistic effect on cytotoxicity in the binary combinations consisting of chlorite and one of the 5 organic DBPs (2 iodinated DBPs (I-DBPs) and 3 brominated DBPs (Br-DBPs)), chlorate and one of the 4 organic DBPs (3 aromatic DBPs and dibromoacetonitrile), and bromate and one of the 3 organic DBPs (2 I-DBPs and dibromoacetic acid). The possible synergism mechanism of organic DBPs on the inorganic ones may be attributed to the influence of organic DBPs on cell membrane and cell antioxidant system. This study revealed the toxic interactions among organic and inorganic DBPs, and emphasized the latent adverse outcomes in the combined use of different disinfectants.