河流型饮用水水源保护区划分技术方法研究--以淮河淮南段某水厂为例

划定饮用水水源地保护区是保护环境、确保供水质量的有效手段。通过对国内外饮用水水源保护区划分方法的研究进程分析,以HJ/T 338—2007《饮用水水源保护区划分技术规范》为依据,通过实例研究河流型水源保护区划分技术方法。     

Temporal and spatial patterns of micropollutants in urban receiving waters

Based on a monitoring program over the course of a year, we characterize the temporal and spatial distribution of selected micropollutants in an urban watershed within the city of Leipzig, Germany. Micropollutants revealed a ubiquitous presence in untreated and treated wastewater, surface water and groundwater. The loads of 4-nonylphenol in the effluents of the municipal wastewater treatment plant followed a seasonal trend, whereas the loads of all other micropollutants were highly variable and not correlated to seasons. In the surface water, load seasonality of caffeine, galaxolide and tonalide resulted from a rapid removal with increased water temperature. The loads of 4-nonylphenol and of caffeine in the colder months increased when rainfall occurred. In the groundwater, complex spatial and temporal patterns were apparent and were related to varying input, retardation and removal processes. As a consequence, an assessment of micropollutants in urban waters should consider different micropollutants' temporal and spatial variability.     

Geochemical processes of mercury in Wujiangdu and Dongfeng reservoirs, Guizhou, China

The geochemical processes of mercury in Dongfeng (DF) and Wujiangdu (WJD) reservoirs, which were constructed in 1992 and 1979, respectively in Wujiang River, which is the upper branch of Yangtze River were investigated. One sampling site was chosen upriver of 1 km from the dam for each reservoir. Three sampling campaigns were conducted at these sampling sites in December 2003, April 2004 and July 2004, respectively. The distributions of different mercury species in the water column, sediment, and sediment pore water were studied. We found that the sediment is the net source of both inorganic and MeHg to the water column for both reservoirs. The MeHg diffusion fluxes in WJD reservoir at all sampling campaigns were significantly higher than those in DF reservoir. Our study demonstrated that the high primary productivity in the reservoir produced elevated organic matter content that would favor the methylmercury production in sediment.     

The occurrence of antihistamines in sewage waters and in recipient rivers

Background, aim and scope  Each year, large quantities of pharmaceuticals are consumed worldwide for the treatment and prevention of human and animal diseases. Although the drugs and the metabolites observed in the wastewaters and in the environment are present at concentrations several orders of magnitude lower than the concentrations required to exert their effects in humans or animals, their long-term impact on the environment is commonly not known. In this study, the occurrence of six antihistamines, which are used for the relief of allergic reactions such as hay fever, was determined in sewage treatment plants wastewaters and in recipient river waters. Materials and methods  The occurrence of the antihistamines cetirizine, acrivastine, fexofenadine, loratadine, desloratadine and ebastine in sewage treatment plants wastewaters and in recipient river waters was studied. The analytical procedure consisted of solid-phase extraction of the water samples followed by liquid chromatography separation and detection by a triple-quadrupole mass spectrometer in the multiple reaction mode. Results  Cetirizine, acrivastine and fexofenadine were detected in both influent and effluent wastewater samples at concentration levels ranging from about 80 to 220 ng/L, while loratadine, desloratadine and ebastine could not be detected in any samples. During sewage treatment, the concentration of the antihistamines dropped by an average of 16–36%. Furthermore, elevated concentrations of antihistamines were observed in samples collected during the season of most intensive plant pollen production, i.e. in May. In the river water samples, the relative pattern of occurrence of cetirizine, acrivastine and fexofenadine was similar to that in the wastewater samples; although the concentration of the compounds was substantially lower (4–11 ng/L). The highest concentrations of the studied drugs were observed near the discharging point of the sewage treatment plant. Discussion  The highest concentrations of antihistamines in STP wastewaters correlate with the outbreak of allergic reaction caused by high amounts of plant pollens in the air. The analysis results of the river water samples show that the antihistamines are carried far away from the effluent discharge points. They may account for a part of the mix of pharmaceuticals and of pharmaceutical metabolites that occur downstream of STPs. Conclusions  Antihistamines are poorly degraded/eliminated under the biological treatment processes applied in the wastewater treatment plants and, consequently, they are continuously being discharged along with other drugs to the aquatic environment. Recommendations and perspectives  As a huge quantity and variety of drugs and their metabolites are continuously discharged to rivers and the sea, the compounds should be considered as contaminants that may possess risks to the aquatic ecosystem. Further studies are urgently needed on the environmental fate of the antihistamines and other pharmaceuticals in the aquatic environment. These studies should be concerned with the stability of the compounds, their transformation reactions and the identity of the transformation products, the distribution of drugs and their uptake and effects in organisms. On the basis of these studies, the possible environmental hazards of pharmaceuticals may be assessed.     

三垟湿地沉积物-间隙水-上覆水界面磷形态研究

沉积物与上覆水间营养物质交换,成为导致水体发生富营养化的首要化学变迁过程.分别在三垟湿地的柑橘林(S1)、景观用地(S2)和生活用地(S3)取样,研究了沉积物-间隙水-上覆水界面磷形态以及相互关系.结果表明:(1)沉积物TP增加时,间隙水PO3-4和可溶性总磷(TDP)也增加.要削减磷在上覆水中的含量,控制间隙水PO3-4或TDP是一良策.(2)随着沉积物铁磷、铝磷的增加,间隙水PO3-4也增加.在三垟湿地沉积物中,铁磷和铝磷含量都可作为间隙水PO34-含量的指示.(3)S1、S2和S3的沉积物活性磷、间隙水TDP和上覆水TDP存在明显的浓度梯度,沉积物活性磷＞间隙水TDP＞上覆水TDP.说明在三垟湿地中,沉积物活性磷是磷释放的关键因子,而沉积物-间隙水界面则是磷释放的关键界面.     

苏南某市河流水质参数时空变异性研究

以苏南某市区320km2内的河流为研究对象,基于对高锰酸盐指数、NH3-N、TP3个主要水质参数的监测,应用地质统计学的变差函数球状模型和Kriging插值法,对河流有机污染指标、富营养化指标进行了空间插值,用以揭示其时空分布特征及变化趋势,并绘制了时空分布等值线图。结果表明,受不同区域污染物来源的差异、不同河道自身条件的差异和不同水期水生植物、入流水量、河水流动性的差异等因素的影响,研究区河流水质参数呈现出不同的时空变异特征;各水质参数污染均相当严重,尤以富营养化指标氮磷最为显著。     

固相萃取—气相色谱—质谱测定再生水中邻苯二甲酸酯类物质

探讨了一种再生水中邻苯二甲酸酯类物质的测定方法——固相萃取—气相色谱—质谱,检测了相关再生水标准中涉及的邻苯二甲酸二丁酯(DBP)和邻苯二甲酸二(2-乙基己基)酯(DEHP)两类物质。在质量浓度为20～1 000μg/L时,两类物质的回归方程的相关系数均大于0.999,检出限分别是0.060、0.002μg/L,DBP、DEHP的相对标准偏差分别为4.1%～7.4%、5.1%～6.1%。利用固相萃取技术进行预处理,平均加标回收率为96.6%、89.6%。检测了北京市4座再生水厂出水中DBP和DEHP含量,其中,DBP在1.74～5.59μg/L,低于《城市污水再生利用景观环境用水水质》(GB/T 18921—2002)规定的限值(不超过0.1mg/L),但高于《城市污水再生利用地下水回灌水质》(GB/T 19772—2005)规定的限值(不超过3μg/L);DEHP在0.42～4.93μg/L,满足GB/T 19772—2005要求(不超过8μg/L)。     

改性多壁碳纳米管对水中Cd~（2＋）的去除

为了增加多壁碳纳米管（multiwall carbon nanotubers,MWNTs）对水中Cd2＋的吸附量,使用混酸对多壁碳纳米管进行氧化处理,采用红外光谱进行结果表征,并探讨了吸附时间、pH值和MWNTs的使用量、Cd2＋的浓度及干扰离子对镉离子吸附的影响。结果表明,吸附时间为1.5 h、pH为5.3、吸附效果最佳,随MWNTs量的增加Cd2＋去除量增加,共存的阳离子会降低对Cd2＋的吸附效果,对Cd2＋的吸附符合Longmuir吸附定律。研究同时表明,pH小于2时Cd2＋能容易从碳纳米管上解吸。初步探讨了Cd2＋吸附机制。     

湘江株洲段丰水期镉污染负荷总量测算及分配

以2010年8月湘江干流株洲段代表性断面水质与底泥监测资料以及其他资料为基础,采用WASP7模型模拟该江段丰水期镉浓度,并进行镉污染负荷测算与分配。研究结果表明,WASP7模型较好地重现了镉浓度的变化规律,8月份该河段上游镉入流量2 446.33 kg,下游出流量3 076.44 kg,区间增量630.12 kg,其中点源负荷量241.67 kg,占38.4%,面源负荷量304.49 kg,占48.3%,内源负荷量为83.96 kg,占13.3%。     

螺、蚌对污水处理厂再生水环境的改善稳定作用

通过选用昆明市第五污水处理厂的一级A标出水和水处理厂外排污泥作为静态实验环境,研究不同混养密度下铜锈环棱螺、椭圆背角无齿蚌对污水处理厂再生水环境的净化性能,筛选出净化效果较好的放养密度。结果表明:放养30 d,铜锈环棱螺、椭圆背角无齿蚌对污水处理厂再生水环境的水质、底质均有一定的净化作用,扣减空白对照影响,水中COD、TP、NH3-N及底泥有机质平均去除率分别为22.26%、26.10%、25.60%和25.69%,底泥厚度平均减少3.8 cm;与对照相比,放养螺蚌45 d内水均能清澈见底,透明度均>70 cm,能明显稳定水体透明度,改善水环境。综合螺蚌生长适应性和净化效果考虑:污水处理厂再生水静态环境中,螺蚌混养密度应≤3 000 g/m3,在2 000～2 500 g/m3为宜,其中铜锈环棱螺的最适放养密度在400 g/m3,椭圆背角无齿蚌为1 600～2 100 g/m3。