Development of GIS based contamination risk assessment in water distribution systems

The study aims at developing a GIS based contamination Risk Assessment procedure in water distribution systems. Water distribution network analysis model EPANET 2.0 was integrated with ArcGIS 8.3 for the water quality analysis retrieving data from the GIS database. Water supply system of Zone VIII of Guntur, India was selected for the case study. The results of water quality simulation were displayed in the GIS interface and the areas affected were mapped with the spatial analyst tool of GIS. Data on number of household connections and standpipes affected by a particular event of contamination was also retrieved from the GIS database. The events resulting in high risk were identified from the GIS maps. This information helps in the decision making process of prioritizing the maintenance activities particularly, in case of limited fund availability. Since the resource availability for maintenance activities are limited in developing countries, prioritizing the activities using GIS helps to achieve maximum risk reduction

Community wells for sustainable irrigation in tank commands: a case study

An optimization model has been formulated to maximize the net benefit from a tank command with conjunctive use of surface water from the tank and ground water from wells and community well in the tank area. The Kannangudi tank in Pudukkottai district, Tamil Nadu, India has been taken as the case study. Six crops were found in the command area and are considered for arriving the optimal cropping pattern. The study result shows that, the wells and community well in a tank command contributes to a sustainable irrigation and apparently maximize the net benefit from that tank command

Microwave-assisted synthesis and anti-inflammatory activity evaluation of some novel α-aminophosphonates

<p>An expeditious green synthetic approach was developed for the synthesis of α-aminophosphonates in good yields through one-pot three component reaction (Kabachnik-Fields reaction) of equimolar quantities of <i>N</i>-(4-amino-2-phenoxy phenyl)methanesulfonamide, diethylphosphite and various aldehydes under conventional as well as microwave irradiation methods. The newly synthesized compounds were characterized by NMR (³¹P, ¹H, and ¹³C), Mass, IR and C, H, N analyses. The synthesized compounds were screened for their anti-inflammatory activity using rat paw edema method. Most of the compounds from the series showed good anti-inflammatory activity when compared with standard drug. Especially the compounds <b>5d</b> bearing 4-hydroxy-3-nitrophenyl moiety, <b>5e</b> bearing 3-bromo-4-fluorophenyl moiety, <b>5g</b> incorporated with 2,4-dichlorophenyl moiety and <b>5f</b> containing 4-chlorophenyl moiety exhibiting edema inhibition of 91.01% to 85.39% after 4 h of carrageenan injection while the other compounds displayed inhibition ≥75%.</p

Solvent-free sonochemical kabachnic-fields reaction to synthesize some new α-aminophosphonates catalyzed by nano-BF₃•SiO₂

<p>To obtain a rapid, efficient synthesis of some new α-aminophosphonates, ultrasonic irradiation has been applied to the reaction mixtures containing amine, aromatic or heteroaromatic aldehydes and triethyl phosphite. The Kabachnik-Fields reaction was performed by using nano-BF₃•SiO₂ as a recyclable catalyst under solvent free conditions. Key advantages of this procedure consist in the eco-friendly and highly efficient reaction conditions, high yields, an easy work-up procedure, short reaction times and solvent free conditions. All title compounds were characterized by spectral and elemental analysis. They were further screened for their <i>in vitro</i> antioxidant activity by the DPPH, O²⁻ and NO methods. The majority of the title compounds showed good antioxidant activity when compared with the standard antioxidants.</p

Molecular Facts on the Structure and Dynamics of Electrolyte Species in Cu–Cl Cycle for Hydrogen Generation: An Insight from Molecular Dynamic Simulations

The Cu complex, which is the key chemical species in well-known Cu–Cl hybrid thermochemical cycles and also in numerous metal hydrometallurgical and sedimentary deposit processes, displays a wide variety of structural and dynamical characteristics that are further complicated by the presence of multiple oxidation states of Cu ions with different coordination chemistries, therefore they are difficult to explore from experiments alone. In this article, an attempt has been made to understand the coordination behavior of the Cu complex using MD simulations. The study provides compelling evidence of the experimentally observed multiple stoichiometries of Cu ions, i.e., 1:6:0, 1:5:1, and 1:4:2 for Cu⁺:H₂O:Cl^– and 1:6:0 for Cu²⁺:H₂O:Cl^–. The presence of the anionic Cu complex, [Cu⁺Cl₂]⁻·2H₂O, [Cu⁺Cl₂]⁻·3H₂O, [Cu²⁺Cl₃]⁻·H₂O, and [Cu²⁺Cl₃]⁻·2H₂O, was captured in the presence of excess chloride ions. Furthermore, the probability distribution profiles have been estimated to determine the most possible complex in the considered systems. The results establish structural and dynamical reformation of the Cu complex with change in the salt concentration or variation in the solvent medium in which they are dissolved. Moreover, the structure and kinetics of the Cu ions in the Cu–Cl electrolyzer have been explored over a large range of the electric field by extending the simulated systems for varied strengths of the electric fields. It has been observed that with an increase in the strength of the electric field, the water molecules lose their coordination strength with central Cu ions, which, on the other hand, results in a significant change in the structure of the captured complex. The diffusion dynamics of the ions is altered while applying the electric field, which is furthermore modified while increasing the strength of electric field beyond a critical limit. In fact, the diffusion mechanism of the ions was seen to be transformed from Brownian-like to linear motion and then to hopping diffusion with the increasing strength of the electric field. To the best of our knowledge, this is the first time when the multiple oxidation states of the Cu ion are explored using MD simulations, and the coexisting pictures of the multiple coordinations and the solvent effects have been clearly revealed. Also to date, the present article is the first one to report the insights of the structure and the dynamics of the ions in the Cu–Cl electrolyzer over a wide range of the electric field. The present studies will be very helpful in understanding the mechanism involved in numerous metal hydrometallurgical and sedimentary deposit processes and to comprehend the analogies involved in the electrode reactions of the Cu–Cl cycle for hydrogen generation

Water safety plans - Book 3: Risk assessment of contaminant intrusion into water distribution systems

This book has been written specifically for practitioners involved in the operation, maintenance and management of piped water distribution systems in urban areas of developing countries. These practitioners include engineers, planners, managers, and water professionals involved in the monitoring, control and rehabilitation of water distribution networks. The book explains in detail how to evaluate the risk of deterioration of the water distribution network of a water supply system. It begins with the conceptualization of risk evaluation and its three different components (hazard, vulnerability and risk). The book further elaborates on each of these three components, explains the methodologies used to estimate the components, and presents the background to the mathematical models. Finally, the book explains how these components are integrated to form a GIS-based decision support system for risk evaluation. The book is designed to help practitioners understand the concept of risk evaluation and supports the manual of the IRA-WDS software, a GIS-based decision support system for risk evaluation. The IRA-WDS software is developed for the evaluation of risk to piped water distribution systems in urban areas of developing countries. The user of this software needs to know about the consideration of different factors, data type and requirement, which may vary from one region to another. The user can understand the concept of evaluation from this book and decide upon the importance of the different factors involved and associated data collection. It should be noted that combining this book with Water Safety Plans Book 1 provides the decision-maker with a valuable tool to assess the overall risk of contaminant intrusion into a water supply system. It is also important to consider this book in relation to Water Safety Plans Book 2, as it is imperative that the institutions and authorities responsible for water management have the capacity to use and implement IRA-WDS, and also to recognize the importance of developing an integrated approach to water management. The WEDC Water Safety Plans series comprises: Book 1: Planning Water Safety Management for Urban Piped Water Supplies in Developing Countries; Book 2: Supporting Water Safety Management for Urban Piped Water Supplies in Developing Countries; Book 3: Risk Assessment of Contaminant Intrusion into Water Distribution Systems; Book 4: IRA-WDS Software and Manual for Risk Assessment of Contaminant Intrusion into Water Distribution Systems