Monitoring of (bio)available labile metal fraction in a drinking water treatment plant by diffusive gradients in thin films

A performance study of diffusive gradients in thin films (DGT) and inductively coupled plasma optical emission spectrometry (ICP-OES) was applied for the monitoring of the labile fraction of metals Al, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn, in Sant Joan Despí Drinking Water Treatment Plant located in the South of Barcelona’s Metropolitan Area (Spain). The DWTP monitoring protocol was optimized by working for 1 day of deployment (24 h) with the DGT device in contact with both treated and river water matrixes. Additionally, it was demonstrated that an increase in the deployment time of 1 week did not decrease the evaluated concentrations of the studied metals. The quality parameters of the DGT device and ICP-OES determination, such as limit of quantification, accuracy expressed as relative error (%) and reproducibility expressed as relative standard deviation, were evaluated. Good results were obtained for all the metals in ultrapure water; limits of quantification ranged from 1.5 μg L^− 1 for cadmium to 28 μg L^− 1 for zinc when deployment time of 24 h was used and from 0.2 μg L^− 1 for cadmium to 4 μg L^− 1 for zinc when this time was increased by 1 week. Accuracy and precisions lower than or equal to 10% were obtained at a parametric concentration value of the metals regulated in the European Drinking Water Guidelines (98/83/EC). DGT deployment was tested in river and treated water, and good results were obtained for Cd, Ni, Co and Zn, whereas for the other metals, a continuous control of their metallic labile fractions was monitored. Therefore, DGT device allows the continuous monitoring of the labile metal species in a drinking water treatment plant.     

A statistics-based system for treatment plant operation

This paper describes work toward development of a convenient computer system to improve everyday operation and control of the wastewater treatment process. The goal is to help the operator detect the problems in the process and to select appropriate control actions. The system comprises subsystems for a data base management, data analysis including several statistical methods, and an expert advisory system. The statistical methods investigated include construction of external reference distributions, computation of moving averages, graphical methods, discriminant functions for early detection of upsets, and several kinds of control charts. The latter two methods are still under development and are not built into the system. Reference distributions are used to help define the fuzzy terms such as high and low for the conditions of the variables involved in the expert system control rules. The system is written in dBase-III and Lotus-123 and has a user-friendly interface for the communication between the user and the system.     

A new attachment device for deployment of monitoring equipment in estuaries and other high-energy environments

Biomonitoring is an important component of estuarine research and monitoring programs because living organisms integrate biological, chemical, and physical conditions over time. The deployment of biomonitoring devices in ecosystems that are subject to changes in water level and flow can be very challenging. This paper describes a new device, which facilitates such applications such as the deployment of periphytometers. The device is designed to encircle posts, poles, or pilings, such as channel markers common in many waterways. This device has been evaluated and approved for use by the US Coast Guard, needed for attachment to navigational aids. It allows attachment of monitoring devices requiring in situ deployment at fixed water depths in systems with dynamic water levels or velocities while minimizing the potential for shading, damage, theft, or poor long-term performance.     

Forest biomonitoring of the largest Slovene thermal power plant with respect to reduction of air pollution

The condition of the forest ecosystem in the vicinity of the largest Slovene power plant [the ?o?tanj Thermal Power Plant (?TPP)] was monitored during the period 1991–2008 by determining the total concentration of sulphur, ascorbic acid and chlorophyll in Norway spruce needles. After 1995, the introduction of cleaning devices at the ?TPP dramatically reduced the former extremely high SO₂ and dust emissions. The most significant findings of this comprehensive, long-duration survey are as follows: (1) the chosen parameters are suitable bioindicators of stress caused by air pollution in Norway spruce needles; they reflect both spatial and temporal variations in air pollution as well as the degree of efficiency of the cleaning devices; (2) observations show that the physiological condition of Norway spruce in northern Slovenia has significantly improved since 1995, when the first desulphurization device at ?TPP was built, together with a reduction in the area influenced by pollution from ?TPP; (3) metabolic processes in spruce needles react to air pollution according to the severity of the pollution and the length of exposure; exposure to high SO₂ ambient levels and/or spread over a long duration can damage the antioxidant defence mechanisms of spruce trees as well as diminishing the concentration of ascorbic acid; (4) a reduction in the exposure to air pollution improves the vitality of the trees (e.g. higher concentrations of total (a?+?b) chlorophyll), as well as restoring their defence capabilities as shown by higher concentrations of ascorbic acid; and (5) forest monitoring should be continued and focused on integrating the effects of multiple stressors, which can additionally affect a forest ecosystem.     

Field surveys for potential ozone bioindicator plant species in Argentina

In Argentina no historical or present programs exist specifically assessing ecosystem health with respect to photochemical air pollution, although phytotoxic concentrations of near-ground ozone have been documented in recent years. Here we report our preliminary findings on field observations of ozone-like injury found in natural plant populations and agroecosystems late in the 2005 growing season in the Southern Hemisphere. Several possible ozone bioinidicator plants which have not been previously documented were observed to exhibit foliar symptoms consistent with ozone-induced injury. Based on these results we intend to expand field surveys and complete the screening process for injury confirmation of the plant species described here. For this and future research we will be using controlled chamber studies based in the US. Continuous monitoring of tropospheric ozone does not currently take place in the region of central Argentina. The combined evidence provided by intermittent air quality sampling and the presence of ozone-like injury to vegetation indicates the need to establish air quality and ozone biomonitoring networks in this region.     

A Passive Sampler for Monitoring Urban Particulate: Preliminary Results

A passive sampling device, developed for personal monitoring of airborne dust levels in industry, has been tested as a site sampler in the urban environment. The device weighs approximately 15g and the essential sampling element is a small disc of electret material (polymer carrying a permanent electric charge). During use it captures particles by electrical attraction, at a rate that depends upon their electrical mobility, but which is independent of the rate at which air flows past the sampler. It collects measurable quantities of particulate, though the sample size tends to be small and correlation with results from conventional samples has not yet been established. Samplers have been exposed to urban particulate for periods of up to seven days, without the electret suffering unacceptable loss of electric charge. It has been shown to be potentially useful for long-term monitoring, a situation in which dispensing with a power source is particularly useful. Being small, the passive sampler is easy to hide or camouflage. It has potential for multiple simultaneous site sampling and for monitoring personal environmental exposure.     

A method for characterising natural and waste waters using plant seeds

Studies were conducted to describe a method for the characterisation of natural and waste waters using plant seed germination as a technique for toxicity testing. Maize seeds were found to be more sensitive to differences in water quality than cowpea seeds and also showed more consistency in results. Trials conducted using natural waters and effluents from gold mining and textile manufacturing operations are also reported.     

Toxicity assessment for petroleum-contaminated soil using terrestrial invertebrates and plant bioassays

The assessment of soil quality after a chemical or oil spill and/or remediation effort may be measured by evaluating the toxicity of soil organisms. To enhance our understanding of the soil quality resulting from laboratory and oil field spill remediation, we assessed toxicity levels by using earthworms and springtails testing and plant growth experiments. Total petroleum hydrocarbons (TPH)-contaminated soil samples were collected from an oilfield in Sfax, Tunisia. Two types of bioassays were performed. The first assessed the toxicity of spiked crude oil (API gravity 32) in Organization for Economic Co-operation and Development artificial soil. The second evaluated the habitat function through the avoidance responses of earthworms and springtails and the ability of Avena sativa to grow in TPH-contaminated soils diluted with farmland soil. The EC₅₀ of petroleum-contaminated soil for earthworms was 644 mg of TPH/kg of soil at 14 days, with 67 % of the earthworms dying after 14 days when the TPH content reached 1,000 mg/kg. The average germination rate, calculated 8 days after sowing, varied between 64 and 74 % in low contaminated soils and less than 50 % in highly contaminated soils.     

生物生态耦合技术处理农村生活污水的应用研究

在对“厌氧池+跌水充氧接触氧化池+水耕蔬菜型人工湿地”生物生态耦合技术应用于农村生活污水处理进行实证研究的基础上，进一步探讨了生物与生态处理单元各自的主要去除对象和效率，为生物生态技术的合理耦合提供了依据。结果表明：在进水COD、TN、TP质量浓度波动范围为51.20~211.12，28.29~122.12，1.26~5.97mg/L时，出水平均质量浓度为15.80，5.51，0.34mg/L，出水水质达到《城镇污水处理厂污染物排放标准（GB 18918—2002）》一级A标准。污水中COD、TN、TP的78%，85%，50%的去除是在生物处理单元完成的，而TP的达标排放还必需生态处理单元的参与。整个处理技术处理效果良好，运行费用低，适合在条件允许的农村地区推广使用。     

Soil sampling and analysis for volatile organic compounds

Concerns over data quality have raised many questions related to sampling soils for volatile organic compounds (VOCs). This paper was prepared in response to some of these questions and concerns expressed by Remedial Project Managers (RPMs) and On-Scene Coordinators (OSCs). The following questions are frequently asked:

1. Is there a specific device suggested for sampling soils for VOCs?
2. Are there significant losses of VOCs when transferring a soil sample from a sampling device (e.g., split spoon) into the sample container?
3. What is the best method for getting the sample from the split spoon (or other device) into the sample container?
4. Are there smaller devices such as subcore samplers available for collecting aliquots from the larger core and efficiently transferring the sample into the sample container?
5. Are certain containers better than others for shipping and storing soil samples for VOC analysis?
6. Are there any reliable preservation procedures for reducing VOC losses from soil samples and for extending holding times?

Guidance is provided for selecting the most effective sampling device for collecting samples from soil matrices. The techniques for sample collection, sample handling, containerizing, shipment, and storage described in this paper reduce VOC losses and generally provide more representative samples for volatile organic analyses (VOA) than techniques in current use. For a discussion on the proper use of sampling equipment the reader should refer to other sources (Acker, 1974; U.S. EPA, 1983; U.S. EPA, 1986a). Soil, as referred to in this report, encompasses the mass (surface and subsurface) of unconsolidated mantle of weathered rock and loose material lying above solid rock. Further, a distinction must be made as to what fraction of the unconsolidated material is soil and what fraction is not. The soil component here is defined as all mineral and naturally occurring organic material that is 2 mm or less in size. This is the size normally used to differentiate between soils (consisting of sands, silts, and clays) and gravels. Although numerous sampling situations may be encountered, this paper focuses on three broad categories of sites that might be sampled for VOCs:

1. Open test pit or trench.
2. Surface soils (<5 ft in depth).
3. Subsurface soils (>5 ft in depth).

     

Validation of plant based bioassays for the toxicity testing of Indian waters

Plant-based bioassays have recently gained remarkable popularity among the toxicological/eco-toxicological assessment procedures. The reasons for their wide use are comparative simplicity, sensitivity, and cost-effectiveness as well as a good correlation with other toxicity tests. The present study describes the use of two plant bioassays, Allium cepa test and seed germination test in the evaluation of the toxicity/genotoxicity of industrial waste water and river water and standardization with the commonly occurring pollutants in Indian waters namely heavy metals and phenolics. Both tests were standardized to suit the Indian conditions, and the local varieties were used. Both bioassays responded significantly with the test range of heavy metals and phenolics. The toxicity of heavy metals was in the order of Cu > Ni > Cd in both the tests whereas 2,4-dinitrophenol was the most toxic among the phenolic compounds. Cabbage, millet, and cucumber, respectively, were found to be the most sensitive in the seed germination test for the test heavy metals and phenols. Significant amounts of chromosomal abnormalities including bridges, stickiness, and fragmentations were recorded with both the industrial waste water and the XAD concentrated river water samples by A. cepa test.     

The high potential of Pelargonium roseum plant for phytoremediation of heavy metals

The major objective of this investigation was to evaluate the potential of scented geraniums, Pelargonium roseum, to uptake and accumulate heavy metals nickel (Ni), cadmium (Cd), or lead (Pb). For this, plants were grown in an artificial soil system and exposed to a range of metal concentrations over a 14-day treatment period. Then, metals from the entire biomass were extracted. The results showed that scented geranium plants accumulated in excess of 20,055 mg of Ni kg^?1 dry weight (DW) of root and 10,889 mg of Ni kg^?1 DW of shoot, and in excess of 86,566 mg of Pb kg^?1 DW for roots and 4,416 mg of Pb kg^?1 DW for shoots within 14 days. Also, the uptake and accumulation of cadmium in roots of scented geranium plants increased with the exposure at low (250, 500 mg?L^?1) and medium level (750 mg?L^?1) followed by a decline at the highest level (1,000 mg?L^?1). The highest accumulation in roots (31,267 mg?kg^?1 DW) was observed in 750 mg?L^?1 cadmium treatment. In the shoots of scented geraniums, the highest amount of metal accumulation (1,957 mg?kg^?1 DW) was detected at 750 and 1,000 mg?L^?1 of cadmium in the culture solution. Finally, since the high concentrations of Ni or Pb accumulated in shoots of scented geranium has far exceeded 0.1 % DW and for Cd has far exceeded 0.01 % DW, P. roseum is a new hyperaccumulator species for these metals and can be used in phytoremediation industry.     

可伸缩延长气体采样装置在应急监测中的应用

提出了一种可伸缩延长气体采样装置,并将其与现场气体监测仪器配套使用。初步考察了延长采样装置中Teflon采样管长度对现场监测结果可能产生的影响,并对监测站实验室楼顶废气排出筒气体进行了实际样品监测。结果表明,该装置可有效提高现场应急监测的安全防护保障效果,增加可监测区域范围,使现场应急监测工作能够为突发性环境污染事件的处置提供更多技术支持。     

微小流量大气采样器自动检定装置的研究

介绍了微小流量大气采样器自动检定装置的检测原理 ,给出了该检定装置用于计算的数学模型 ,主要通过对各分量标准不确定度进行分析和计算 ,得到该检定装置测量的扩展不确定度 ,并证明建立该自动检定装置适用于微小流量大气采样器的检定工作     

直接采样法确定面源恶臭挥发率的研究进展

确定面源恶臭挥发率的方法一般有两种:间接采样法和直接采样法.直接采样法由于具有许多优点而得到了广泛的应用.采样设备的选择会影响到恶臭样品的组成,通过对比可知,由动态采样器和静态采样器确定的恶臭挥发率的结果是不同的.用风洞法确定的恶臭挥发率与用问接法确定的恶臭挥发率有较好的一致性,可以作为恶臭扩散模型的输入参数.     

Evaluation and assessment of environmental protection alternatives for the Jeddah cement company plant

An environmental impact assessment is conducted by utilizing monitoring, meteorological, and physical modeling data. This information serves as input to a decision analysis of the environmental protection alternatives for the cement plant in Jeddah, Saudi Arabia. Utility theory provides the methodology underlying the Evaluation and Sensivity Analysis Program (ESAP) with which the alternatives are evaluated. Recommendation include: (1) installation of electrostatic precipitators of at least 99% efficiency, (2) institution of a 1.6 km nonresidential zone given the present 60 m chimneys, and (3) substitution of low sulphur fuel for the crude oil now consumed. By illustration this study suggests the general relevance of the ESAP program to environmental assessment and management.     

ANFIS-based modelling for coagulant dosage in drinking water treatment plant: a case study

Coagulation is the most important stage in drinking water treatment processes for the maintenance of acceptable treated water quality and economic plant operation, which involves many complex physical and chemical phenomena. Moreover, coagulant dosing rate is non-linearly correlated to raw water characteristics such as turbidity, conductivity, pH, temperature, etc. As such, coagulation reaction is hard or even impossible to control satisfactorily by conventional methods. Traditionally, jar tests are used to determine the optimum coagulant dosage. However, this is expensive and time-consuming and does not enable responses to changes in raw water quality in real time. Modelling can be used to overcome these limitations. In this study, an Adaptive Neuro-Fuzzy Inference System (ANFIS) was used for modelling of coagulant dosage in drinking water treatment plant of Boudouaou, Algeria. Six on-line variables of raw water quality including turbidity, conductivity, temperature, dissolved oxygen, ultraviolet absorbance, and the pH of water, and alum dosage were used to build the coagulant dosage model. Two ANFIS-based Neuro-fuzzy systems are presented. The two Neuro-fuzzy systems are: (1) grid partition-based fuzzy inference system (FIS), named ANFIS-GRID, and (2) subtractive clustering based (FIS), named ANFIS-SUB. The low root mean square error and high correlation coefficient values were obtained with ANFIS-SUB method of a first-order Sugeno type inference. This study demonstrates that ANFIS-SUB outperforms ANFIS-GRID due to its simplicity in parameter selection and its fitness in the target problem.     

多参数环境自动监测数据采集传输装置研究

为加强环境自动监测系统的建设,提供了一个支持多种类型现场信息宽接入的信息采集、支持有线和无线信息传输的开放式在线数据采集传输装置.装置用标准化的工控机作为控制核心,具备模拟信号、LonWorks信号、视频信号、RS-485信号输入接口,网络通信和GPRS远程通信方式,采用Windows操作系统和数据库技术,应用方便灵活,有助于提供有效、客观的现场环境信息,实现环境自动监测与管理.