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This paper reports the ozone generation in pulsed multichannel dielectric barrier discharge. The influence of nitrogen addition (0.1%-10%) on ozone concentration and ozone generation efficiency in nitrogen-oxygen gas mixtures is studied. Results show that adding 0.1% N2 would not seriously increase the ozone production. Meanwhile, 1% N2 content exhibits the highest ozone production efficiency in low SIE (J/L, defined as the ratio of power to gas flow rate) region (0-200 J/L) while adding 0.3% N2 would lead to the highest ozone generation efficiency in high SIE region (300-800 J/L). The increase of ozone production induced by N2 addition is more significant in low SIE region compared with that in high SIE region. At 100 J/L, ozone production efficiency increases 26.9% to 201.6 g/kWh with 1% N2 addition when compared with that in oxygen. At 18 J/L, the observed maximum ozone generation efficiency reaches 252 g/kWh at 1.3 g/Nm3 with 1% N2 addition. An increase of ozone production can be obtained with 0.3%-2% N2 addition in all explored SIE ranges. [ABSTRACT FROM AUTHOR]

Highly sensitive detection of Pb 2+ is very necessary for water quality control, clinical toxicology, and industrial monitoring. In this work, a simple and novel DNAzyme-based SERS quadratic amplification method is developed for the detection of Pb 2+ . This strategy possesses some remarkable features compared to the conventional DNAzyme-based SERS methods, which are as follows: (i) Coupled DNAzyme-activated hybridization chain reaction (HCR) with bio barcodes; a quadratic amplification method is designed using the unique catalytic selectivity of DNAzyme. The SERS signal is significantly amplified. This method is rapid with a detection time of 2 h. (ii) The problem of high background induced by excess bio barcodes is circumvented by using magnetic beads (MBs) as the carrier of signal-output products, and this sensing system is simple in design and can easily be carried out by simple mixing and incubation. Given the unique and attractive characteristics, a simple and universal strategy is designed to accomplish sensitive detection of Pb 2+ . The detection limit of Pb 2+ via SERS detection is 70 fM, with the linear range from 1.0×10 –13 M to 1.0×10 −7 M. The method can be further extended to the quantitative detection of a variety of targets by replacing the lead-responsive DNAzyme with other functional DNA. [ABSTRACT FROM AUTHOR]

Magnetic multi-wall carbon nanotubes (M-MWCNTs) were used as an adsorbent for removal of furaltadone from aqueous solutions, and the adsorption behaviors were investigated by varying pH, sorbent amount, sorption time and temperature. The results showed that the adsorption efficiency of furaltadone reached 97% when the dosage of M-MWCNT was 0.45 g . L-1, the pH was 7 and the adsorption time was 150 min. The kinetic data showed that the pseudo-second-order model can fit the adsorption kinetics. The sorption data could be well explained by the Langmuir model under different temperatures. The adsorption process was influenced by both intraparticle diffusion and external mass transfer. The experimental data analysis indicated that the electrostatic attraction and π-π stacking interactions between M-MWCNT and furaltadone might be the adsorption mechanism. Thermodynamic analysis reflected that adsorption of furaltadone on the M-MWCNT was spontaneous and exothermic. Our study showed that M-MWCNTs can be used as a potential adsorbent for removal of furaltadone from water and wastewater. [ABSTRACT FROM AUTHOR]

Across the U.S., municipalities are experiencing unprecedented regulatory requirements, budgetary limitations, and shortage of available space and resources. To manage these challenges and preserve water quality, municipalities must seek innovative solutions. A recent project demonstrates that with thorough understanding of the collection system, hydrologie/ hydraulic modeling, a comprehensive study of alternatives, and a little ingenuity, municipalities nationwide can meet (or exceed) regulatory requirements while saving money along the way. [ABSTRACT FROM AUTHOR]

Water reclamation and reuse practices are recently receiving growing attention due to increasing water scarcity, concerns about the effect of wastewater discharges on receiving water, and availability of high-performing and cost-effective water reuse technologies. However, incorporation of water reuse schemes into water/wastewater infrastructure systems is a complex decision making process, involving various economical, technological, and environmental criteria. System dynamics (SD) allows modeling of complex systems and provides information about the temporal and feedback behavior of the system. In this sense, a SD model of the existing water/wastewater system in Kalamazoo-Michigan, an urban area in the Great Lakes region, was created with the hypothetical incorporation of water reuse. The model simulates and optimizes the overall water system cost (including water, wastewater and water reuse components), accounting for future scenarios of population, economic growth and climate change. Results indicate significant levels of water reuse after an infrastructure build delay. The model also indicates that a decision to implement water reuse yields remarkably lower water withdrawals and lower water treatment costs even in a location with a relatively abundant water supply like Kalamazoo. This study emphasizes the fact that a true understanding of the practice of water reuse cannot be achieved without taking regional and climatic parameters into account. [ABSTRACT FROM AUTHOR]

Strategies are sought to reduce the impact of nonpoint sources of pollution, including fecal bacteria, and meet TMDL criteria. Vegetative filter strips (VFSs) are one such strategy, though the data of VFS function under field conditions, particularly for fecal bacteria, are limited. The objective of this study was to evaluate the efficiencies in removing fecal bacteria, N, and P from VFSs installed to treat contaminated runoff from a working feedlot. VFSs were found to be effective in removing a broad range of constituents from beef feedlot runoff pretreated by a settling basin. The first 30 m provided most or all of the reductions found within the 150 m VFSs studied: reductions average 85% of inflow water, 85% of sediment, 77% of N, and 84% of P. Fecal bacteria removal by the VFSs was about one order of magnitude: reductions at 30 m ranged from 83.5% for FC and FS to 91% for E. coli. On the site being studied, this provided an important level of protection and reduced surface-flow concentrations of fecal coliforms to below the 200 CFU/100 mL (coliform-forming units, CFU) water-quality standard for Kansas. [ABSTRACT FROM AUTHOR]

The article discusses various types of corrosion damages and its impact on water-cooled systems. It identifies ways on how to recognize corrosion damages, which is said to cause basic problems such as failure of equipment and decreased in process throughput. It relates methods on how to control and monitor corrosion in cooling water environments.

The 1972 Clean Waler Act initiated a national effort to address all sources of waler pollution. One outcome was development of forestry nonpoinl source control programs that use best management practices (BMP) and rnother tools to minimize water quality impacts. These programs can only be successful. if BMPs are effective and if implementation rates are high. Many states have assessed rates of forestry BMP implementation with more than one survey and are beginning to develop histories that track trends. Trend data at the regional and national levels show generally high and increasing levels of implementation. Here, we use the volume of timber harvested in each state to adlust contributions to a national implementation average. The overall national forestry BMP implementation rate is estimated to be 89%. Factors contributing to increased implementation include federal and stale legislation, regulation, and extension; certification programs; and public pressure. [ABSTRACT FROM AUTHOR]

Recent years have seen the arrival of an array of early warning systems for the continuous on-line detection of anomalies relating to water security and quality. Numerous methodologies and criteria have been suggested to determine the efficacy of these methods in real-world scenarios. The authors contend that many of these evaluation techniques are deficient in evaluating all of the factors that would be essential in defining a system for deployment for the protection of key installations such as military bases. They suggest specific criteria as a means of comparing various technologies and propose a new method for determining receiver operating characteristic curves. Similar considerations should come into play in the evaluation of systems for civilian uses. [ABSTRACT FROM AUTHOR]

Abstract: One third of the world population does not have access to clean water sources and most of these people are not connected to the electrical grid at the same time. Therefore, photovoltaic (PV) powered water purification suggests itself to be one of the solutions in areas with high sun radiation like India or the MENA (Middle East and North Africa) region. Furthermore, the environmental impact of the process can be reduced substantially as no fuel supply is required. The paper presents a concept of combining a membrane filtration plant with PV power supply only. As PV is a fluctuating energy source and the conventional membrane process needs a constant power input to maintain pressure and flow on the membranes to guarantee their lifetime, some challenges in the system design need to be addressed. Mere coupling of off-the-shelf components does not do the job. A full-scale system for sustainable water purification has been designed and tested in the lab and a pilot location. The results are presented in the paper. Beyond the environmental benefits, the system also competes with standard systems on the market. Based on the experimental results, a cost model has been derived, the main cost factors for the system will be established and a design strategy for a small-scale PV powered system, able to supply a farm or village with safe potable water, is presented. [Copyright &y& Elsevier]

Abstract: The paper lists and reviews the issues, considerations and factors that faced planners in Israel in introducing large scale seawater desalination plants within the national and regional water supply systems. Most importantly, the paper quantifies the cost and benefit consequences of these factors, thereby establishing their relative weight, importance and significance. Cost consequences relate not only to the effect each factor had on desalinated water costs at their inlets to the national or regional water supply grids, but also to its effect on overall investments and operating costs related to expanding the entire water supply system to meet projected increases in demand, including seasonal, multi-seasonal and local storage capacities, distribution line sizes, pumping energy requirements, etc., and to dealing with deteriorating groundwater quality, including rehabilitation of salinized and/or contaminated wells, etc. Benefits included factors such as potable water supply reliability and quality enhancement, expanded and environmentally safer water reuse potential, etc. As will be shown, the challenge was to create a master plan which accounts for all these factors and optimizes their overall cost-benefit ratio both short and long term. [Copyright &y& Elsevier]

Abstract: In this paper, optimal operating rules for water quality management in reservoir–river systems are developed using a methodology combining a water quality simulation model and a stochastic GA-based conflict resolution technique. As different decision-makers and stakeholders are involved in the water quality management in reservoir–river systems, a new stochastic form of the Nash bargaining theory is used to resolve the existing conflict of interests related to water supply to different demands, allocated water quality and waste load allocation in downstream river. The expected value of the Nash product is considered as the objective function of the model which can incorporate the inherent uncertainty of reservoir inflow. A water quality simulation model is also developed to simulate the thermal stratification cycle in the reservoir, the quality of releases from different outlets as well as the temporal and spatial variation of the pollutants in the downstream river. In this study, a Varying Chromosome Length Genetic Algorithm (VLGA), which has computational advantages comparing to other alternative models, is used. VLGA provides a good initial solution for Simple Genetic Algorithms and comparing to Stochastic Dynamic Programming (SDP) reduces the number of state transitions checked in each stage. The proposed model, which is called Stochastic Varying Chromosome Length Genetic Algorithm with water Quality constraints (SVLGAQ), is applied to the Ghomrud Reservoir–River system in the central part of Iran. The results show, the proposed model for reservoir operation and waste load allocation can reduce the salinity of the allocated water demands as well as the salinity build-up in the reservoir. [Copyright &y& Elsevier]

Transmission lines with distributed parameters are often used as electrical energy storage units and high-voltage (high-current) pulse shapers in electrophysical facilities. To increase the pulse power and reduce the dimensions of the equipment, deionized water, purified from mechanical impurities and gas, is used as an insulator in lines. Water has a high breakdown strength ((BS) ∼ 130 kV/cm) at pulses with a duration of ∼1 µs and electrode areas of up to tens of square meters, a large value of the relative permittivity (∼80), and a small loss tangent in the frequency range 0–1 GHz. Water also possesses a number of characteristics needed to achieve the above aims. We review here the data on the electrical properties of water and the studies of it published over the last three decades; the methods for increasing the water BS and the influence of numerous factors on the BS; the physical mechanism of water breakdown and the basic regularities of the BS in strong electric fields; the BS in the most frequently used electrode systems; formulas for calculating the water BS under different conditions and over the surfaces of solid dielectrics; the characteristics of mixtures of water and ethylene glycol or methanol; water purification systems for electrophysical facilities; the comparative parameters of coaxial energy storage units having various insulators, etc. The summary generalizes the brief and predominantly reference information on the electrical properties of water and its applications for researchers, engineers, and the users of the equipment having water insulation; it can help to solve related problems more quickly and reliably. [ABSTRACT FROM AUTHOR]

Presents updates on several equipment used in water systems as of October 2002. SA-500 Scanning Analyzer, which measures lead contamination, from Palintest; Well-Off sampler, a minimum-purge ground water sampling system, from Learned Technologies; Mini 122 Interface Meter from Solinst.

Focuses on the development of a submersible spectrometer for the measurement of the dynamic behavior of water resources in terms of its quality and quantity. Effectiveness of the technology after testing for multi-parameter measurements directly in the medium; Advantage of the technology from conventional grab sampling and laboratory analysis; Features of the submersible spectrometer.

Informs about water flow and level measuring equipments. System 1010DN Permanent Clamp-On Transit-Time Multifunction Flowmeter; VL650 Wafer-Style Liquid Flowmeter; Tank dewatering system from the AGAR Corp.; Visual flow indicators; Sewer flow metering; Pressure transducers.

Presents a list of water and wastewater treatment products and the names of the companies that supply them. Activated Carbon; Aeration, equipment and systems; Algaecides; Others.

Highlights various products for water engineering and management. Water Analysis Handbook; Intelligent Control Open Network (ICON) electric actuator; Camera transporter; More.

Presents information on various equipment used in the water management industry. Functions of electromagnetic flow meters; Level transmitters from Bindicator Level Instrumentation; Area velocity flow meter lines from American Sigman company; How a microwave moisture monitor functions.

The author discusses the need for a real-time and continuous monitoring system for biological contaminants in water. It is asserted that very few monitoring devices that use nucleic acid are capable of detecting viruses. Developing devices and methodologies that can detect all classes of microorganisms for routine monitoring and field testing is suggested.

Introduces products for water engineering and management. Includes a sludge pump from V-Ram Solids; Sizetec High Performer screen from Sizetec Inc.; Sonologic II microprocessor-based non-contracting open channel flow monitor from Kistler-Morse; Insulating gasket kits from Advance Products & Systems.

The article evaluates various products for groundwater quality maintenance and monitoring including the Model 3500 AquaVent data logger from Solinst, Water Well Calculator from Cotey Chemical Corp., and Well Sounder 2010 PRO water level indicator from Eno Scientific LLC.