An Innovative Index for Evaluating Water Quality in Streams

A water quality index expressed as a single number is developed to describe overall water quality conditions using multiple water quality variables. The index consists of water quality variables: dissolved oxygen, specific conductivity, turbidity, total phosphorus, and fecal coliform. The objectives of this study were to describe the preexisting indices and to define a new water quality index that has advantages over these indices. The new index was applied to the Big Lost River Watershed in Idaho, and the results gave a quantitative picture for the water quality situation. If the new water quality index for the impaired water is less than a certain number, remediation—likely in the form of total maximum daily loads or changing the management practices—may be needed. The index can be used to assess water quality for general beneficial uses. Nevertheless, the index cannot be used in making regulatory decisions, indicate water quality for specific beneficial uses, or indicate contamination from trace metals, organic contaminants, and toxic substances.     

Routine, automated determination of inorganic and total mercury in multimedia using cold vapour atomic absorption spectrometry

A routine, automated analytical method for simultaneous determination of total and inorganic mercury by cold vapour atomic absorption spectrometry in multimedia is described. Excellent accuracy and precision results were obtained with human hair certified reference materials namely, BCR-397 and IAEA-086. The reproducibility relative standard deviation for total mercury was 4% and 22%, respectively. The limit of detection for total and inorganic mercury was 0.2 μg/g hair. The described method has been successfully applied in determination of total and inorganic mercury as well as organic mercury in human hair, urine and fish tissue samples.     

Wastewater effects on a waterhyacinth marsh and adjacent impoundment

A waterhyacinth (Eichhornia crassipes) marsh occupying two-thirds of the basin of a small Florida impoundment has received sewage effluent for nearly 20 years. Water from the marsh flows into an area that is maintained free of waterhyacinths, and is discharged through wells at the far end of the impoundment. A water budget for the basin was estimated, and phosphorus concentrations were measured monthly at three stations in the marsh and at the discharge wells in the lake. Productivity levels were measured monthly where the marsh joins the lake and at the discharge wells. Only 16% of the phosphorus that enters the basin is stored. Gross primary productivity levels in the open-water areas are very high (22 gO₂m²day), but high respiration rates appear to keep the lake in steady-state.     

湖泊富营养化相关物理量的定量关系

湖水中总磷、总氮、叶绿素a、透明度、均温层氧亏量是与水体富营养化密切相关的几个物理量。研究结果表明,它们之间有一定的相关关系,可用数学公式定量表示。本文针对这些关系进行了概括和整理。     

Total organic halogen (TOX) in human urine: A halogen-specific method for human exposure studies

Disinfection by-products(DBPs) are a complex mixture of compounds unintentionally formed as a result of disinfection processes used to treat drinking water. Effects of long-term exposure to DBPs are mostly unknown and were the subject of recent epidemiological studies. However,most bioanalytical methods focus on a select few DBPs. In this study, a new comprehensive bioanalytical method has been developed that can quantify mixtures of organic halogenated compounds, including DBPs, in human urine as total organic chlorine(TOCl), total organic bromine(TOBr), and total organic iodine(TOI). The optimized method consists of urine dilution, adsorption to activated carbon, pyrolysis of activated carbon, absorption of gases in an aqueous solution, and halide analysis with ion chromatography and inductively coupled plasma-mass spectrometry. Spike recoveries for TOCl, TOBr, and TOI measurements ranged between 78% and 99%. Average TOCl, TOBr, and TOI concentrations in five urine samples from volunteers who consumed tap water were 1850, 82, and 21.0 μg/L as X~-, respectively.Volunteers who consumed spring water(control) had TOCl, TOBr, and TOI average concentrations in urine of 1090, 88, and 10.3 μg/L as X~-, respectively. TOCl and TOI in the urine samples from tap water consumers were higher than the control. However, TOBr was slightly lower in tap water urine samples compared to mineral water urine samples, indicating other sources of environmental exposure other than drinking water. A larger sample population that consumes tap water from different cities and mineral water is needed to determine TOCl, TOBr, and TOI exposure from drinking water.     

石墨炉原子吸收分光光度法测定土壤中总铬

建立了土壤中总铬测定的石墨炉原子吸收分光光度法;以塞曼效应扣除背景,优化了石墨炉灰化、原子化温度、停留时间及基体改进剂用量。结果表明:当原子化温度为2 700℃,灰化温度为700℃,原子化时间2 s,灰化时间为9 s;基体改进剂用量为3~5μL时,仪器可以达到最佳工作状态。该方法铬元素浓度在0~32μg/L内呈良好的线性关系,相关系数r=0.999 9,检出限为0.3 mg/kg;对土壤标样GSS-1和ESS-1的铬测定精密度均小于5%,相对误差在-4.8%~-0.7%之间,方法的灵敏度和准确度均符合要求。因此,石墨炉原子吸收分光光度法测定土壤中总铬具有原子化温度高、干扰少、灵敏度高等特点可适用土壤中总铬的测定。     

胶州湾入海污染物目标总量控制研究

根据对胶州湾水质的实际调查结果,确定DIN,COD为胶州湾的主要污染因子。对胶州湾陆源污染物现状入海量进行调查,并以2008年为基准年,以COD,NH3-N为预测因子,预测2010年胶州湾各排污单元污染物增加情况。提出基于现实、分阶段实行目标总量控制的总量分配原则,根据国家和山东省给青岛市下达的总量控制指标和2008年青岛主要污染物实际排放情况,确定2010年胶州湾COD排放总量控制目标为34675t,NH3-N入海通量总量控制目标为6943t,并对各排污单元的排放总量控制目标值进行了分配。     

测定废弃钻井泥浆中石油类分析方法的探讨

本文旨在规范泥浆样品的分割、前处理、萃取方法和测定结果表达方式。采用自行设制的泥浆分割器迅速冷冻和解冻方法,均匀、快速地完成泥浆样品的制备;通过对两种前处理方法精密度和加标回收率实验结果的分析比较,论述了现行泥浆前处理方法的弊端,证实了均匀分割全量萃取法具有样品缩分科学、省时保鲜、全量萃取等优点,提高了样品分析的精密度和准确度。     

排放绩效法用于沈阳市燃煤电厂二氧化硫总量控制目标研究

介绍排放绩效法在火电企业二氧化硫指标控制方面的应用,根据沈阳市"十一五"二氧化硫总量控制要求制定了排放绩效标准,并利用绩效法对各燃煤电厂二氧化硫总量控制指标进行了测算,提出了总量分配方法。     

紫外分光光度法测定总氮空白值过高原因分析

碱性过硫酸钾消解紫外分光光度法测定总氮过程中,常常发生空白值过高而影响测定的情况,可能造成空白值过高的原因很多．主要包括纯水质量、试剂纯度、实验条件等几个方面,通过对可能造成总氮测定空白值过高的各项原因进行逐一系统分析和试验．发现造成空白值过高的原因主要为试剂过硫酸钾纯度不够,含有的总氮杂质过高所致,采用二次重结晶的方法时过硫酸钾试剂提纯后使用。同时严格地按照标准方法要求控制实验条件,即可大大降低总氮测定的空白值。