苏州城区河道水质现状分析

跟踪了苏州城区内27个重点河流断面半年的监测数据,重点监测了溶解氧、氨氮、总磷、高锰酸盐指数4个富营养化指标。计算了各种污染物单因子污染指数、主要污染物分担率和平均污染指数,并对水质污染程度进行综合评价。结果表明,在苏州城区河道的27个重点监测断面中,大部分属于中度污染,水体的主要污染物为溶解氧、氨氮和总磷。分析了可能导致城区河道水体污染的主要原因,并提出治理建议。     

太湖流域断头河道微循环水质效应与生物响应

针对太湖流域断头河道微循环过程中水质效应和生物响应不清楚的问题,笔者通过水槽模拟实验,分析了氮磷和有机物等水质指标随水体微循环时间、频率的变化关系;通过常州武进洛阳镇徐家头浜实际河道微循环实验,探讨了微循环运行过程中实际河道水质的稳定性,微循环过程中实际河道的生物响应,及浊度、溶解氧、pH等环境因素的影响。结果表明：水槽模拟实验条件下微循环对水体氨氮去除的影响最为明显（去除率达62.91%）,COD去除率变化幅度受微循环频率的影响最大（可达50%）;微循环设置后实际河道COD浓度下降趋势明显（降幅约30%）;微循环过程中河道水体浮游动物和浮游植物数量均呈上升趋势,而河道边坡和底泥中Proteobacteria、Bacteroidetes、Actinobacteria、Acidobacteria等优势微生物菌群的丰度却有不同程度的变化。同时,浊度对总磷和COD的影响程度相当,溶解氧和pH对水体氨氮浓度的影响均最显著。该研究为改善断头河道水质提供新方向,为微循环技术的实际应用提供数据参考。     

基于自动监测网络的湘江流域衡阳段铊污染原因分析

运用自动监测网络与实验室验证相结合的手段,通过测定湘江流域衡阳段干流与支流铊浓度,分析铊浓度与溶解氧含量、氨氮浓度及叶绿素a浓度等水质指标的关系,进而对湘江流域衡阳段铊污染进行原因分析。结果表明,2021年8月上旬,湘江流域衡阳段干流铊污染的来源主要为多支流污染汇入。其中,松木下游断面铊污染极有可能来源于支流上游企业排放,江东水厂断面铊浓度异常的原因主要为溶解氧降低、死藻富集。该案例可为我国铊污染应急监测及污染原因分析提供借鉴。     

用YSI—58型溶氧仪测定五日生化需氧量的注意事项

YSI—58型溶解氧测定仪,配上带有搅拌器的五日生化需氧量专用探头,可用于五日生化需氧量分析。由于该仪器具有操作快速、简便、干扰少、测定结果准确、运行费用低等特点,深受分析工作者欢迎。美国已列为分析五日生化需氧量的标准方法。在《水与废水监测分析方法(第3版)》也将膜电极法作为测定溶解氧的方法之一。根据几年来的工作经验,在用YSI—58型溶氧仪分析五日生化     

大气颗粒物采样器的设计与应用

自行开发设计大气颗粒物双通道采样器,通过更换粒径切割器实现对大气总悬浮颗粒物(TSP)、可吸入颗粒物(PM10)或细颗粒物(PM2.5)样品的采集。该仪器通过流量传感器、比例阀和流量控制板精确控制每个通道的采样流量,控制系统还可实时采集大气环境温度、压力、湿度、风速和风向5个气象参数,并根据环境温度、压力的变化对采样的体积流量进行补偿计算,以确保进样口体积流量恒定,保证粒径切割准确。在2011年深圳大学生运动会期间(8月12—23日)和后期(8月24日至9月4日),利用该仪器进行了大气环境野外观测实验,并对该仪器和Thermo2300采样器的结果进行了平行性分析和对比分析,其平行结果和对比结果相关系数均大于0.99。     

东平湖突发性水污染事故调查

东平县环境监测站从1996年开始,对每年发生的第一场洪水进行水质跟踪监测。结果表明,SS是主要污染物,涨洪段和洪峰段监测值分别超过《渔业水质标准》(GB1160789)181倍、215倍,TN的高峰值出现在退水段1和退水段2,分别超过《地表水环境质量标准》(GB38382002)Ⅲ级标准6 54倍、5 68倍,洪峰的COD监测值为133mg/L,超标5 65倍。洪水入湖后湖区水质监测结果表明,老湖镇入湖口河道污染最重,除上游洪水带入大量污染物外,洪水入湖后冲击养殖区,使大量含有机质的底质泛起,加重了入湖口附近的水污染。指出,悬浮物的骤然增加和溶解氧的持续过低,大汶河流域内地表水水质恶化以及养殖区规划不合理和养殖方式不当是导致污染事故发生的主要原因。     

湖北省地表水水质评价指标及监测方式研究

选取湖北省100个国控断面2019年1—12月手工和自动监测数据,采用因子分析和聚类分析相结合的方法对水质评价指标进行优化筛选,结果表明,高锰酸盐指数、氨氮、总磷、pH、溶解氧等5项指标可以代表湖北省地表水水质的主要影响因子,从而实现水质监测指标的降维。对手工和自动2种监测方式进行比对,证明自动监测pH、溶解氧、高锰酸盐指数、总磷和氨氮5项水质评价指标的数据、评价结果与手工监测具有较强的一致性,用自动监测5项指标进行水质评价是合理、可行的,并能减轻手工监测的工作量。     

深水湖泊溶解氧值稳定性探讨

通过对千岛湖水体溶解氧值的监测研究表明 ,水体中的溶解氧值不稳定 ,在一天内有较大的波动 ,最低值出现在早晨日出之前 ,最高值出现在下午日落之前 ,水样极差夏季为 3 .2 1 mg/L ,冬季为2 .78mg/L;垂向分布不均匀 ,溶解氧值随水深的增加而减小 ,即表层为峰值 ,底层为谷值 ,在水深为80 m的水体中 ,极差夏季为 1 .41 mg/L,冬季为 1 .1 5 mg/L。由此可见 ,深水湖泊水体中的溶解氧分布无论在时间上还是在空间上都有较大的差别。在水环境质量监测中 ,每一水期对每一点位的溶解氧仅作二次监测 ,且每点次的采样时间又不一致 ,用这样的二次瞬时值…     

深水湖泊溶解氧值稳定性探讨

通过对千岛湖水体溶解氧值的监测研究表明 ,水体中的溶解氧值不稳定 ,在一天之中有较大的波动范围 ,最低值出现在早晨日出之前 ,最高值出现在下午日落之前 ,水样极差夏季为 3.2 1 mg/L,冬季为 2 .78mg/L;垂向分布不均匀 ,溶解氧值随水深的增加而减少 ,即表层为峰值 ,底层为谷值 ,在水深为 80 m的水体中 ,极差夏季为1 .41 mg/L,冬季为 1 .1 5 mg/L。由此可见 ,深水湖泊水体中的溶解氧分布无论在时间上还是在空间上都有较大的差别。在水环境质量监测中 ,每一水期对每一点位的溶解氧仅作两次监测 ,且每点次的采样时间又不一致 ,用这样的两次…     

釜溪河自贡城区段季节性低氧成因研究

釜溪河为沱江一级支流,在自贡城区段设有国考碳研所断面。收集碳研所断面近10年来水质自动站数据,分析溶解氧(DO)变化特征,采样调查釜溪河自贡城区段水质及河道底泥污染状况,采用相关性分析、数值模拟等,研究分析釜溪河自贡城区段溶解氧分布特征及碳研所断面季节性低氧成因。研究结果表明,碳研所断面的溶解氧质量浓度变化特征呈现春末夏初最低,白天高晚上低的特征。釜溪河碳研所断面河水耗氧类污染物质量浓度较沱江流域内其他断面高,耗氧强度较大,溶解氧质量浓度较沱江流域其他断面偏低;其次,研究河段中釜溪河污水厂以下河段受污水厂低氧水排入和金子凼堰底层低氧水下泄影响,其溶解氧水平整体较污水厂以上河段低;最后,河段底泥有机质含量较高,春夏季气温升高将导致微生物分解活性增强大量消耗溶解氧,同时,闸坝和外来水体排入的水文扰动造成污水厂以下河段水温梯度弱,表层溶解氧易受底层低氧水影响,促使断面形成季节性低氧现象。溶解氧预测模型结果也进一步证实了温度变化和垂向温度梯度弱是碳研所断面溶解氧质量浓度季节性偏低的主要因素。     

Water quality assessment using integrated modeling and monitoring in Narva Bay, Gulf of Finland

A coupled three-dimensional hydrodynamic–ecological model was used for the assessment of water quality in Narva Bay during one biologically active season. Narva Bay is located in the south-eastern Gulf of Finland. Narva River with a catchment’s area covering part of Russia and Estonia discharges water and nutrients to Narva Bay. The ecological model includes phytoplankton carbon, nitrogen and phosphorus, chlorophyll a, zooplankton, detritus carbon, nitrogen and phosphorus, inorganic nitrogen, inorganic phosphorus and dissolved oxygen as state variables. Both the hydrodynamic and ecosystem models were validated using a limited number of measurements. The hydrodynamic model validation included comparison of time series of currents and temperature and salinity profiles. The ecological model results were compared with the monitoring data of phytoplankton biomass, total nitrogen and phosphorus and dissolved oxygen. The comparison of hydrodynamic parameters, phytoplankton biomass, surface layer total phosphorus and dissolved oxygen and near-bottom layer total nitrogen was reasonable. Time series of spatially mean values and standard deviations of selected parameters were calculated for the whole Narva Bay. Combining model results and monitoring data, the characteristic concentrations of phytoplankton biomass, total nitrogen and phosphorus and near-bottom dissolved oxygen were estimated. Phytoplankton biomass and total phosphorus showed seasonal variations, of 0.6–1.1 and 0.022–0.032 mg/l, respectively, during spring bloom, 0.1–0.3 and 0.015–0.025 mg/l in summer and 0.2–0.6 and 0.017–0.035 mg/l during autumn bloom. Total nitrogen and near-bottom oxygen concentrations were rather steady, being 0.25–0.35 and 2–6 mg/l, respectively. The total nitrogen and phosphorus concentrations show that according to the classification of Estonian coastal waters, Narva Bay water belongs to a good water quality class.     

丹江口库区及其上游流域水质污染特征及评价

根据丹江口库区及其上游河流5个区域42个断面2012-2013年的水质监测数据，采用主成分分析法确定主要污染因子及权重，对不同流域的水质进行综合评价。第一主成分包括总氮、溶解氧、五日生化需氧量、总磷、氨氮、高锰酸盐指数，第二主成分为氟化物、粪大肠菌群，第三主成分为化学需氧量；其权重分别为5．022，2．256，1．508。评价结果表明，湖北十堰市和丹江口市流域水环境污染相对较重，其次为河南南阳市、陕西商洛市、陕西安康市以及陕西汉中市流域。     

Assessing the influence of nutrient reduction on water quality using a three-dimensional model: case study in a tidal estuarine system

A coupled three-dimensional hydrodynamic and water quality model has been developed and applied to the Danshuei River estuarine system and adjacent coastal sea. The water quality model considers various species of nitrogen, phosphorus, organic carbon, and phytoplankton as well as dissolved oxygen and is driven by a three-dimensional hydrodynamic model. The hydrodynamic and water quality models were validated with observations of water surface elevation, velocity, salinity distribution, and water quality parameters. Statistical error analysis shows that predictions of hydrodynamics, salinity, dissolved oxygen, and nutrients from the model simulation quantitatively agreed with the observed data. The validated model was then applied to predict water quality conditions as a result of a reduction in nutrient loadings based on different engineering strategies. The simulated results revealed that the dissolved oxygen concentration would increase significantly and would be higher than 2 mg/L in the main stream and in three tributaries to meet the minimum statutory requirement for dissolved oxygen. Active estuarine management focused on the reduction of anthropogenic nutrient loads is needed for improvement in water quality.     

The Water Quality Of The CÉrtima River Basin (Central Portugal)

The aim of this study was to evaluate the water quality of the Cértima River basin (Central Portugal). For that purpose, surface water samples were collected in March, May and July 2003, at 10 selected sampling sites, and were analysed for physicochemical parameters, namely temperature, conductivity, pH, total suspended solids, dissolved oxygen, biochemical oxygen demand (BOD₅), Kjeldahl nitrogen and total phosphorus. Results revealed an acceptable water quality during the spring season. Maxima of 64 mg dm⁻³ for BOD₅, 39 mg dm⁻³ for Kjeldahl nitrogen, and 5.2 mg dm⁻³ for total phosphorus, were recorded during summer, indicating a significant degradation of the water quality in a river stretch located downstream of the town of Mealhada. These values, which did not comply with the objectives of minimum quality for surface waters prescribed by the Portuguese legislation, were related to domestic wastewater discharges and runoff waters from a cattle farm. Besides their effects on the middle stretch of the river, these pollution sources were the most likely cause of the high nutrient load in downstream waters, and thus may have a major impact on the trophic status of Pateira de Fermentelos, a sensitive wetland area located in the lower Cértima basin.     

Sensitivity Analysis and Water Quality Modeling of a Tidal River Using a Modified Streeter–Phelps Equation with HEC-RAS-Calculated Hydraulic Characteristics

A modified Streeter–Phelps equation and the Hydrological Engineering Centers River Analysis System (HEC-RAS) were combined to assess water quality of the Tan-Sui River and its tributaries. The Tan-Sui River is the main source of water supply for northern Taiwan, and the water quality of its stream is significantly affected by tides. In this study, HEC-RAS was employed to assess the impact of tides on water quality and to calculate reoxygenation coefficients. The modified Streeter–Phelps equation was used to calculate water quality in terms of contaminant degradation and reoxygenation. Biochemical oxygen demand (BOD) and ammonia nitrogen (NH₃–N), the most important identified sources of water pollution in the rivers investigated, were evaluated. Dissolved oxygen (DO) was also simulated, since it is often used as a staple of water quality. Results showed that employing HEC-RAS for hydraulic calculations improves the modified Streeter–Phelps simulation. In river sections without tidal influence, water quality was sensitive to the BOD and NH₃–N degradation constants. Downstream of Chin-Mei Creek, while the BOD degradation constant decreased by 80%, BOD and DO concentrations increased from 7.1?mg/L to 10.7?mg/L and 5.0?mg/L to 7.2?mg/L, respectively, indicating that water quality was not as sensitive to variations of the BOD degradation constant as expected. The concentrations of DO and BOD at the river mouth had a significant impact on water quality for the tidal sections of the investigated rivers due to mixing of tidal and river waters. The BOD and NH₃–N degradation constants in the tidal sections had little impact on water quality simulations. This study demonstrated the innovative combination of the modified Streeter–Phelps equation and HEC-RAS to assess the impact of tidal variation and to simulate the water quality of a tidal river when available data is rather limited.     

Water quality in Minho/Miño River (Portugal/Spain)

Minho River, also called Miño (in Spain), extends to about 300 km from Spain to Portugal. The source of the river lies in Spain and in the last 75 km, the river defines the border between Portugal and Spain. Under the scope of a cooperation project between North Portugal and Galicia region of Spain, titled: “Valorization of the natural resources of the Minho/Miño drainage basin”, seven water-sampling campaigns were carried out during the last 2 years in Minho River basin. Seven sampling sites were selected along the international stretch, and five were chosen in the main Portuguese and Spanish tributaries of Minho River. Water quality based on the physicochemical and microbial parameters was assessed. According to the Portuguese legislation for surface waters, the international section of Minho River presents a reasonably good water quality (BOD₅ <5 mg/L, TNK <2 mg/L, and total phosphorous <1 mg P/L). Valença and Louro were found to be the most polluted sampling sites and Louro the most polluted tributary (maximum values observed: TSS?=?26 mg/L, BOD₅?=?6.6 mg O₂/L, COD?=?20.8 mg O₂/L, total nitrogen?=?9.9 mg N/L; minimum value observed: OD?=?1.3 mg O₂/L). A one-dimensional stream water quality model QUAL2Kw was calibrated using data measured in field surveys along the international stretch of Minho River. QUAL2Kw was also used to predict the impact of flow conditions, discharges, and tributaries on the water quality of international stretch of Minho River, essential to establish proposals for management and planning of Minho River Basin.     

Nutrients in the Changjiang River

N, P and SiO3-Si in the Changjiang mainstream and its major tributaries and lakes were investigated in the dry season from November to December, 1997, and in the flood season in August and October, 1998. An even distribution of SiO3-Si was found along the Changjiang River. However, the concentrations of total nitrogen, total dissolved nitrogen, dissolved inorganic nitrogen, nitrate and total phosphorus, total particulate phosphorus increased notably in the upper reaches, which reflected an increasing impact from human activities. Those concentrations in the middle and lower reaches of the Changjiang River were relatively constant. Dissolved N was the major form of N and the particulate P was the major form of P in the Changjiang River. The molar ratio of dissolved N to dissolved P was extremely high (192.5-317.5), while that of the particulate form was low (5.6-37.7). High N/P ratio reflected a significant input of anthropogenic N such as N from precipitation and N lost from water and soil etc. Dissolved N and P was in a quasi-equilibrium state in the process from precipitate to the river. In the turbid river water, light limitation, rather than P limitation, seemed more likely to be a controlling factor for the growth of phytoplankton. A positive linear correlationship between the concentration of dissolved N and the river's runoff was found, mainly in the upper reaches, which was related to the non-point sources of N. Over the past decades, N concentration has greatly increased, but the change of P concentration was not as significant as N. The nutrient fluxes of the Changjiang mainstream and tributaries were estimated, and the result showed that the nutrient fluxes were mainly controlled by the runoff, of which more than a half came from the tributaries. These investigations carried out before water storage of the Three Gorges Dam will supply a scientific base for studying the influences of the Three Gorges Dam on the ecology and environment of the Changjiang River and its estuary.     

太阳山湿地浮游植物优势功能群季节演替特征及驱动因子分析

为探明太阳山湿地浮游植物优势功能群季节演替规律及其主要驱动因子,于2019年4月(春季)、7月(夏季)、10月(秋季)和2020年1月(冬季)采样分析了太阳山湿地浮游植物的种类组成、优势种、丰度、生物量及季节变化,同时测定了水环境理化因子指标,采用冗余分析方法研究了浮游植物优势功能群的优势度、丰度与水环境因子之间的关系。结果表明:太阳山湿地浮游植物可分为22个功能类群;优势功能群的季节演替和空间分异特征明显,存在一定的规律性。春、秋、冬3个季节的浮游植物以硅藻门为主,夏季以绿藻门和蓝藻门为主。春季优势功能群主要为D、C、P,以硅藻门种类为主;夏季优势功能群主要为J、Lo、TC、M、H1,以硅藻门、绿藻门、蓝藻门种类为主;秋季优势功能群主要为D、S1、MP,以硅藻门、绿藻门种类为主;冬季优势功能群主要为D、X3,以硅藻门种类为主。影响太阳山湿地浮游植物优势功能群季节演替的水环境因子有水温(WT)、pH、溶解氧(DO)、透明度(SD)、盐度(Sal)、氮磷营养元素含量、化学需氧量(COD_Cr)和高锰酸盐指数(COD_Mn)。4个湖区浮游植物优势功能群的时空差异与水环境因子密切相关,其中,西湖区浮游植物优势功能群的季节演替驱动因子为pH、DO、WT、总磷(TP),东湖区为pH、DO、WT、氮磷营养元素含量,南湖区为pH、DO、COD_Cr、五日生化需氧量(BOD₅),小南湖区为pH、DO、WT、BOD₅、COD_Cr、TP。pH、DO、WT、BOD₅、SD等水环境因子的季节差异以及TP、TN、氨氮(NH₃-N)、COD_Mn等水环境因子的湖区差异是太阳山湿地浮游植物优势功能群出现季节演替的主要原因。     

官厅水库入库断面水质多指标评价与演变特征分析

水体质量状况及其污染特征是流域水污染防治规划和治理措施制定的前提和基础。采用主成分分析和层次聚类分析等多元统计分析方法,选取溶解氧、高锰酸盐指数、化学需氧量等10个不同类型的监测指标,综合评价了官厅水库入库断面八号桥2006—2017年丰水期和枯水期水质年际变化特征,识别了不同阶段关键污染指标。结果表明:各年份丰水期(9月)大多数水质指标均优于枯水期(5月),特别是粪大肠菌群和氨氮,但总磷和高锰酸盐指数的差异较小。根据水质指标年际变化情况,可将研究期分为污染严重阶段(2006—2007年)、污染改善阶段(2008—2015年)和污染全面好转阶段(2016—2017年)。大部分水质指标呈现逐年好转的趋势,特别是粪大肠菌群、氨氮和五日生化需氧量,但总磷仍是官厅水库入库河流的重要污染指标。