鼎湖山森林地表水水质状况分析

对鼎湖山生物圈保护区内两溪流水源水质状况进行了调查,结果发现：①鼎湖山地表水总体水质较好,符合地面水环境质量标准的I类水源水质标准。区内水体受污染程度低,绝大多数指标均符合饮用水卫生标准。②水体pH值较低,Al含量较高,总有机碳测定表现出整个水体受到一定程度的有机污染。水体中有害金属Mn和Pb含量略高,但都远低于饮用水卫生标准。③对地表水来源过程环节的水化学分析比较表明：大气降水、穿透水、土壤溶液（30cm层和80cm层）和地表水水样的pH值呈现“M”形变化。酸雨和土壤表层酸化是该区地表水pH值偏低的主要原因。地表水和30cm土壤溶液中的Al浓度分别是大气降水的5倍和8倍,地表水中的Al主要来源于酸雨对土壤的淋溶。地表水中的Na主要来源于大气降水。大气降水Pb浓度是地表水的17倍,林冠吸收富集和土壤固定吸附使地表水中的Pb大幅度降低。穿透水和土壤溶液中的Mn、K、Ca、Mg、Sr比大气降水和地表水浓度高,反映了元素被酸雨淋溶、活化和被植物、土壤吸收吸附的过程。从长远看,尽管在森林保存完好的地区,区域环境的恶化及酸雨对地表水水质的影响仍不容忽视。     

景洪水库浮游植物群落结构变化及与水质的关系

景洪水库是澜沧江下游的重要梯级开发水库,具有重要的生态战略地位。为评估景洪水库水质和浮游植物群落结构现状,本研究根据库区水位和季节变化在2021年3月、6月、9月开展了库区水质和浮游植物监测。结果表明：景洪水库各监测点位水质较好,满足《地表水环境质量标准》Ⅱ类水质标准,富营养化评价结果为贫营养至中营养,但水质和营养状态从3月至9月呈现逐渐下降的趋势; 3月至9月浮游植物密度增加、多样性降低,随着季节变化浮游植物优势种发生明显改变,3月份优势种为隐藻门（Cryptophyta）和硅藻门（Bacillariophyta）,到9月份库区演变为蓝藻门（Cyanophyta）为主。RDA分析表明总有机碳和透明度与浮游植物群落结构变化显著相关。建议后期需加强景洪水库水生态环境监测与评估,预防水体富营养化和蓝藻水华的发生。     

5种严重影响水质的化学物质

随着社会的发展,生活水平的提高,人们的环境意识越来越强,生活中也越来越关注周围的环境,人们对环境中的水质要求也更加严格。水质监测的项目一般有几十种,由于水的来源不同,监测项目也有不同。水按来源一般分为生活饮用水、地表水和工业废水。工     

飞来峡水库水质现状及其向广州供水能力的探讨

水库供水(特别是对城市的供水)已成为缓解全球水资源供给不足的重要途径。于2001年至2003年的丰水期和枯水期调查分析了新建河流型水库-飞来峡水库的水质、浮游植物群落特征和营养状态。结果表明飞来峡水库水质良好,多数水质指标为地表水Ⅱ水质标准,其营养盐浓度、浮游植物的密度均较低,属于贫中营养。从近几年的水质变化来看,建库后,水质改善明显。通过对广州市饮用水源水水质现状及存在问题的分析,从水质和水量两方面探讨了飞来峡水水库作为广州优质水源地的优势。由于来水量大,水库水质净化能力强,飞来峡水库水质和水量均有保证,可作为广州市重要水源地之一。但今后,在流域管理和水土保持工作更应重视和加强。     

生物毒性自动监测系统在天津饮用水源地的应用

2012 年10 月8 日至11 月11 日选择位于引滦工程明渠段的3 号监测点,使用Toxcontrol 生物综合毒性监测仪开展了饮用水源地生物毒性自动监测研究,并对3 号监测点及其下游4 号监测点的pH 值、氨氮浓度、高锰酸盐指数和溶解氧浓度进行了同步监测。试运行阶段生物综合毒性监测仪实际获取有效数据210 组,样品毒性值介于-52%-21%之间,均小于30%,未超过报警临界值。同步监测所得pH 值、氨氮浓度、高锰酸盐指数和溶解氧浓度均达到国家地表水Ⅲ 类水质标准。统计结果显示,水质指标中的毒性值与氨氮浓度呈显著负相关关系(sig.<0.05),说明在一定浓度范围内氨氮可能促进发光细菌的生长或者增强细菌发光能力。     

长江荆江段的渔业生态环境评价

1997—2002年,对长江荆江段青、草、鲢、鳙产卵场的水环境质量和浮游生物状况进行了调查,并用河流水质综合评价方法和Kolkwitz&Marsson体系法进行了评价。结果表明:在每年5—6月份的青、草、鲢、鳙繁殖季节,仅个别采样点铜或石油类超过渔业水质标准,该江段水质基本符合渔业水质标准和地表水环境质量Ⅱ类标准,能满足青、草、鲢、鳙繁殖对水质质量的要求。浮游生物的指示性表明其水体属于β中污带。       

模糊综合评价模型在浔江梧州段渔业水质评价中的应用

依据2004～2008年浔江梧州段的调查监测结果,根据断面污染因子的特点,选择5个指标(溶解氧、高锰酸盐指数、氨氮、总氮、总磷)作为评价因子,应用模糊(Fuzzy)综合评价模型对其水质状况进行综合评价,计算出各监测断面水质级别.结果表明:浔江梧州段的5项评价指标中,TN的权重较大,该水体中主要污染物为总氮;2个断面均在不同程度上出现了Ⅴ类水质,水质属中度污染;部分时段的水质不符合《地表水环境质量标准(GB3838-2002)》中渔业水域的要求.     

模糊数学评价法在广州花都区地表水质现状评价中的应用

在环境调查和监测的基础上综合评价了广州市花都区地表水环境质量现状,为花都区的污染治理及规划提供了科学依据。在评价过程中,重点讨论了评价因子的选取、权重值的运算,并对其评价的结果与水环境调查的实际状况进行了对比分析。评价结果表明:模糊数学评价的结果与花都区地表水质现状相符,全区地表水质尚可,各水库水质都优于Ⅲ类;但区内工业园排水对地表水有不良影响,天马河井岗桥附近出现石油类污染和有机污染,水质属于Ⅴ类;评价方法有实用价值。     

阿哈水库沉积物-水界面重金属扩散通量

为了解阿哈水库水体中重金属的污染现状,选取了4个典型点位进行夏、冬两季采样分析,研究了上覆水体及沉积物孔隙水中Co、Ni、Cu、Zn、As、Cr及Pb 7种重金属的时空分布规律及其界面扩散通量。结果表明:阿哈水库上覆水体中溶解性重金属的均值含量符合我国《地表水环境质量标准》(GB 3838—2002)Ⅰ类标准与《生活饮用水卫生标准》(GB 5749—2006),未受到重金属污染。夏季分层期,底层水缺氧导致水体As、Co、Cr含量增高,而冬季混合期重金属的垂向变化较小。沉积物孔隙水中重金属浓度均值高于上覆水,且Co与Ni、As呈显著正相关,其在水库中的迁移转化过程受铁锰循环的共同影响; Cu、Zn与Pb存在正相关关系,具有相似的污染来源。分析沉积物-水界面重金属扩散通量显示,Zn保持负扩散,表明沉积物对Zn具有很好的净化吸附效果;而Co、Ni、As、Pb保持正扩散,特别是夏季As的扩散通量达2.07μg·cm~(-2)·a~(-1),对上覆水体可能产生较大的释放风险。研究证实,近十年来阿哈水库水体重金属的污染控制取得了显著的效果。     

长江中下游典型饮用水源地水库水质调查与分析

本文主要以长江中下游典型饮用水源小型水库—德清县对河口水库为例,通过收集近三年内该水库的水污染物数据变化,调查了该水库水质的基本状况,评估了德清县对河口水库富营养化环境问题,提出了一些针对长江中下游典型饮用水源地小型水库的水质管理对策。     

Presence of Giardia cysts and Cryptosporidium oocysts in drinking water supplies in northern Spain

AIMS: To evaluate the prevalence of Cryptosporidium and Giardia in surface water supplies from the province of Alava, northern Spain, and to investigate possible associations among the presence of these pathogenic protozoa with microbiological, physicochemical and atmospheric parameters. METHODS AND RESULTS: A total of 284 samples of drinking and recreational water supplies were analysed. Cryptosporidium oocysts were found in 63.5% of river samples, 33.3% of reservoirs samples, 15.4% and 22.6% of raw water samples from conventional and small water treatment facilities (respectively), 30.8% of treated water from small treatment facilities, and 26.8% of tap water from municipalities with chlorination treatment only. Giardia cysts were found in 92.3% of river samples, 55.5% of reservoirs samples, 26.9% and 45.2% of raw water samples from conventional and small water treatment facilities (respectively), 19.2% of treated water from small treatment facilities, and 26.8% of tap water from municipalities with chlorination treatment only. The presence of Cryptosporidium and Giardia had significant Pearson's correlation coefficients (P < 0.01) with the turbidity levels of the samples, and a number of significant associations were also found with the count levels for total coliforms and Escherichia coli. The samples were positive for Cryptosporidium significantly (P < 0.05) more frequently during the autumn season than during the spring and winter seasons. No significant differences were found in the seasonal pattern of Giardia. A moderate association (r = 0.52) was found between rainfall and the presence of Cryptosporidium oocysts. CONCLUSIONS: Cryptosporidium and Giardia are consistently found at elevated concentrations in surface waters for human consumption from the province of Alava, northern Spain. SIGNIFICANCE AND IMPACT OF THE STUDY: Water treatments based on rapid filtration process and/or chlorination only are often unsatisfactory to provide safe drinking water, a situation that represents an important public health problem for the affected population because of the risk of waterborne outbreaks.     

Assessing water quality of five typical reservoirs in lower reaches of Yellow River,China: Using a water quality index method

To assess water quality of reservoirs in lower reaches of Yellow River using the water quality index (WQI) method and try to compare water quality and main contaminations of mountain and Yellow River reservoirs, water samples were carried out over 6 years. Nine water variables were selected to participate WQI calculation by Principal Component Analysis (PCA). WQI values ranged from 17.8 to 77.8 in five reservoirs, which indicated “good” to “very poor” water quality of reservoirs. No significant differences in WQIs were found between mountain and Yellow River reservoirs. A major finding from our study is that mercury was the main contamination in 5 reservoirs, while TP (total phosphorus) and SO₄ were another main contaminations in mountain and Yellow River reservoirs, respectively. Application of the WQI is suggested to be a helpful tool that enables the public and decision makers to evaluate water quality of drinking reservoirs in lower reaches of Yellow River.     

Isolation of Aeromonas hydrophila from a metropolitan water supply: seasonal correlation with clinical isolates

The occurrence of Aeromonas spp. in the metropolitan water supply of Perth, Western Australia, Australia, was monitored at several sampling points during a period of 1 year. Water within the distribution system conformed to international standards for drinking water but contained Aeromonas spp. in numbers comparable to those in raw surface water, although this water was free of Escherichia coli. Coliforms and E. coli were found in raw surface waters, and Aeromonas spp. were found in raw water from surface and underground sources. Chemical treatment, followed by chlorination at service reservoirs, resulted in water free of E. coli and a decrease in the number of Aeromonas spp. Aeromonas spp. were found in the greatest numbers in summer. Multiple regression analysis showed that growth of Aeromonas spp. in chlorinated water was related to water temperature, residual chlorine, and interaction between these variables. The incidence of Aeromonas-associated gastroenteritis, determined from isolates referred to us for enterotoxin testing, paralleled the pattern of isolation of Aeromonas spp. in water within the distribution systems. We suggest that the presence of Aeromonas spp. in drinking water needs public health appraisal and that further work should be undertaken to permit reevaluation of standards for the quality of drinking water.     

Isolation of Aeromonas hydrophila from a metropolitan water supply: seasonal correlation with clinical isolates.

The occurrence of Aeromonas spp. in the metropolitan water supply of Perth, Western Australia, Australia, was monitored at several sampling points during a period of 1 year. Water within the distribution system conformed to international standards for drinking water but contained Aeromonas spp. in numbers comparable to those in raw surface water, although this water was free of Escherichia coli. Coliforms and E. coli were found in raw surface waters, and Aeromonas spp. were found in raw water from surface and underground sources. Chemical treatment, followed by chlorination at service reservoirs, resulted in water free of E. coli and a decrease in the number of Aeromonas spp. Aeromonas spp. were found in the greatest numbers in summer. Multiple regression analysis showed that growth of Aeromonas spp. in chlorinated water was related to water temperature, residual chlorine, and interaction between these variables. The incidence of Aeromonas-associated gastroenteritis, determined from isolates referred to us for enterotoxin testing, paralleled the pattern of isolation of Aeromonas spp. in water within the distribution systems. We suggest that the presence of Aeromonas spp. in drinking water needs public health appraisal and that further work should be undertaken to permit reevaluation of standards for the quality of drinking water.     

西江调水对珠海市供水水库富营养化的影响及其管理对策

2006-2011年间,对西江珠海段和7座江河抽调水型水库水体总氮、总磷进行的长期监测结果发现,西江水体营养盐水平显著高于7座水库,抽调江河水导致水库营养盐水平在短期内急剧升高,水库富营养化和蓝藻水华问题凸显。7座水库总氮、总磷浓度最低的为3座中型水库:凤凰山水库、乾务水库和大镜山水库;最高的为南屏水库和竹仙洞2座小型水库,小型水库纳污、缓冲和自净能力较弱,更易受抽调来水水质的影响。设立合理的水质调度标准和构建生态工程是减缓调水水库富营养进程的有效措施。通过科学、合理的优化调度,调整水库水力滞留时间,改善水体流动性,能有效降低水库蓝藻水华发生的风险。     

Arsenic and Heavy Metal Concentrations in Drinking Water in Pakistan and Risk Assessment: A Case Study

The present study was performed to assess drinking water quality and potential health risk in the Nowshera District, Khyber Pakhtunkhwa, Pakistan. For this purpose drinking water samples were collected from local available sources and analyzed for physico-chemical characteristics, arsenic (As) and heavy metals. Results revealed high levels of toxic heavy metals such as chromium (Cr), nickel (Ni), lead (Pb), cadmium (Cd), and As contaminations in the drinking water. Results were evaluated for chronic risk including average daily intake (ADI) and hazard quotient (HQ). Among heavy metals the HQ values were highest for Cd (5.80) and As (2.00). Therefore, populations in the study area may be at a low level of chronic toxicity and carcinogenic risk. Statistical analyses showed that contribution of different drinking water sources to the mean contaminant levels in the study area was insignificant (p =.53). Correlation analysis further revealed that anthropogenic activities were the main sources of contamination, rather than geogenic. This study strongly recommends the treatment of urban and industrial wastewater in the vicinity of the study area and provision of safe drinking water.     

Trophic structure of nine Czech reservoirs regularly stocked with piscivorous fish

For nearly 20 years, most Czech reservoirs supplying drinking water have been under statutory protection which permitted reservoir managers to manipulate fish stocks in order to maintain a sustainable water quality. The most common biomanipulative measure adopted was stocking with piscivorous fish (mostly 5 cm fry) using an annual stocking level of approx. 25 000 fish per reservoir. Nine reservoirs were studied for signs of top-down food web effects, as predicted by the trophic cascade hypothesis based on levels of total phosphorus (TP), chlorophyll a (Chl a), zooplankton biomass (ZB) and zooplankton community structure. In all nine reservoirs, only small Daphnia species were recorded, such as D. galeata and D. cucullata. The proportion of large-bodied daphnids retained on a 0.71 mm sieve was less than 10% of the total crustacean biomass in all reservoirs. The relationship of Chl a level – TP, and of ZB – Chl a, was positive under enhanced piscivory and did not differ statistically from the relationships in other reservoirs with natural fish stocks. This implies that bottom-up forces remained stronger than top-down ones in the studied reservoirs, despite the stocking of piscivorous fish. The failure of this attempt at biomanipulation may be due to an insufficient stocking rate of predatory fish and/or inadequate data on the resident planktivorous fish levels.     

A comparative study of chemical contamination in sediments of East River (Dongjiang) and selected reservoirs in Hong Kong

Abstract

The levels of TKN, orthophosphate, heavy metals and trace organics including total PCBs and PAHs in the sediments of the East River (Dongjiang) and various reservoirs in Hong Kong were chemically analyzed. It was found that the sediments of various sections of Dongjing and the Shenzhen Reservoir were contaminated by heavy metals at slight to medium levels. Generally speaking, the highest levels of Cd, Cu, Ni, Pb and Zn were recorded in the middle and lower tributaries of Dongjaing, particularly those near Tangxia and Guanlan. Slight amount of PCBs, PAHs were also detected in the lower sections of Dongjiang, indicating industrial contamination due to economic growth in the 1980–90s. Comparatively, only slight amounts of heavy metals were detected in the sediments of some Hong Kong reservoirs that store imported Dongjiang water. Moreover, trace organics including PCBs and PAHs were rarely detected in the reservoirs of Hong Kong. Nevertheless, the high acidity in the sediments of Hong Kong reservoirs is noteworthy. Results revealed that the Dongjiang waters were purified to a certain extent before being imported to and stored at the Hong Kong reservoirs. At present, health risks from the drinking water of Hong Kong are not apparent. However, the long-term trend of organic and inorganic contamination in Dongjiang should not be overlooked and remedial actions should be taken as early as possible. Collaboration between the governments of Hong Kong and Mainland China in tackling chemical pollution in drinking water is an example of cross-border cooperation and control measures should be stepped up as soon as possible.     

Ecological quality of small mountainous Mediterranean streams (river type R-M4) and performance of the European intercalibration metrics

Ten small streams of high altitude were assigned to the R-M4 intercalibration river type (small/medium Mediterranean mountainous rivers) and examined to determine their benthic macroinvertebrate fauna, their physicochemical and hydromorphological parameters and their water quality, quarterly for two consecutive years. Physicochemical variables were consistent with the mountainous character of the streams and fluctuated within the European Community legislation limits for drinking water. Benthic macroinvertebrate fauna communities were diverse and sensitive to organic pollution, and samples were grouped by time more strongly than place. Site size and catchment area influenced the macroinvertebrate community more than the rest of the measured abiotic variables. The water quality was good or high, but at the smaller streams its interpretation was affected by summer drought. The water quality boundaries of the Hellenic Evaluation System were harmonised with the water quality boundaries of a European benchmark database, according to the methodology followed by the Mediterranean Intercalibration Group. Handling editor: R. H. Norris     

Incidence of mesophilic Aeromonas within a public drinking water supply in north-east Scotland

The motile mesophilic Aeromonas are ubiquitous to a wide variety of aquatic environments including drinking water distribution systems. Concern over the presence of mesophilic Aeromonas in public drinking water supplies has been expressed in recent years as it has been regarded as a pathogenic organism of importance in gastroenteritis. A major drinking water distribution system in north-east Scotland was monitored over a 12 month period to determine the prevalence of mesophilic Aeromonas. These data were examined in relation to chlorine concentration, pH, temperature, rainfall and the standard bacteriological indicators of water quality. Aeromonas were isolated to varying degrees from 21 of the 31 reservoirs investigated. The maximum recovery observed during the study was 605 cfu in 300 ml. The probability of isolation generally decreased with increasing levels of chlorination, although this oxidant was found to be ineffective in many reservoirs. Certain reservoirs with poor chlorination profiles yielded very few isolates, whereas some highly chlorinated sites liberated Aeromonas frequently and in relatively high numbers. A seasonal pattern in the incidence of Aeromonas emerged with infrequent isolation during the winter period increasing to a peak during the summer, with most isolates recovered when water temperature was >12 °C. An association was demonstrated between the pattern of Aeromonas isolations and that of rainfall. No relationship was apparent between incidence of Aeromonas and total heterotrophic plate counts.