Divide and Conquer Partitioning Techniques for Smart Water Networks

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A Fuzzy Early Warning System To Mitigate The Odorous Substances Emitted From A Waste Landfill

"\"Emissions of unpleasant odours are associated to many different types of industrial . activities (e.g. paper mills, tanneries, refineries, slaughterhouses, distilleries, . pharmaceutical industries, etc.), civil and industrial wastewater treatment plants, landfills . and composting plants. Their production is generally related to microbial degradation . processes of putrescible organic substances. . In recent decades, the increasing number of landfills located in residential areas has . attracted the attention of the scientific and technical community, placing greater emphasis . on how odour emissions from landfills can be measured and how they can be diminished. . This paper proposes a Fuzzy Early Warning System (FEWS) for the mitigation of the risk . of exposure to odorous substances emitted from a waste landfill in a highly urbanised . area. A fuzzy logic approach was chosen to tackle the complex task of modelling an . automatic decision support system considering several risk variables, such as the wind . speed, the time derivative of the velocity, the wind direction, the time derivative of the . wind direction and the temperature. Indeed the fuzzy logic approach proved to be very . effective both for its “native” capability to deal with nonlinear models and for the possibility . to take into account heuristic and political rules. . The FEWS takes into account both hazard variables (e.g. the contaminant source . emission rate) and vulnerability and exposure variables (e.g. the distance of the landfill . and the typology of human activities). The case study of a solid waste landfill near Naples . (Italy), located in a densely populated area was considered. . The analysis of odour transport was carried out by using ISCST3-BREEZE developed by . EPA. This allows odour dispersion in air to be assessed as a function of weather . conditions (data provided by Capodichino Airport weather station) and contaminant . emissions (estimated using scientific literature). The FEWS is part of a MATLAB . framework in which the fuzzy input variables considered were modelled with a . “membership function” and the risk mitigation actions (e.g., covering of waste, spraying of . fragrant substances, extraction wells to maintain the landfill body at a pressure below . atmospheric, pressure, etc.) were inferred using a set of SUGENO fuzzy output rules. . The simulation results show that FEWS is very effective as compared to simulations . without any mitigation actions. Indeed the use of FEWS allowed for a considerable . reduction in the number of exceedances in all the sensitive centers analyzed, although in . some cases the FEWS operates also when it does not need. The next steps will consist . in improving the optimization of fuzzy rules and membership functions with other . techniques. \"

A District Sectorization for Water Network Protection from Intentional Contamination

The introduction of cyanide with a backflow attack into a water system was studied. The recent development of techniques for water network sectorization, aimed to improve the management of water systems, represents also an efficient way to protect networks from intentional contamination. The possibility of closing gate valves by a remote control system to create an i-DMA (isolated District Meter Area) can reduce the risk of contamination and thus the extent of damage of a terroristic attack. The study proposes a novel technique for designing i-DMAs compatible with hydraulic performance and optimized for water network protection

Software for partitioning and protecting a water supply network

Water network partitioning (WNP) concerns the implementation of the paradigm of ‘divide and conquer’ in the water supply systems consisting in dividing a water network into k smaller subsystems by gate valves and flow meters. WNP allows improving the management of water distribution systems by transforming into Smart WAter Networks (SWANs) that represent key subsystems of Smart Cities. WNP is possible if water utilities start to use isolating valves (also with control devices) and flow meters. These instruments open new perspectives for the management of water supply systems both in terms of water saving and water protection. Recently, starting from the advantages offered by computing power and network analysis tools, some techniques based on graph partitioning algorithms have been developed by the authors to improve water management and protection, implementing the paradigm of ‘divide and conquer’. This paper presents the second release of SWANP 2.0 (Smart WAter Network Partitioning and Protection) software that integrates two different algorithms, based on multilevel and multi-agent techniques, for WNP and a novel algorithm, based on a multi-objective function, for water network protection from intentional contamination. The SWANP 2.0 software, developed in Python v2.7.6 language, provides the decision-maker different solutions comparing network layouts with some hydraulic and protection performance indices

Application of a discontinuous permeable adsorptive barrier for aquifer remediation. A comparison with a continuous adsorptive barrier

This work presents an innovative configuration of a permeable adsorptive barrier (PAB) for the in situ remediation of benzene-contaminated groundwater in the area of Naples (Italy). A PAB is a type of permeable reactive barrier (PRB) made with adsorbing materials (e.g. activated carbon). This particular PAB is a discontinuous permeable adsorptive barrier (PAB-D), consisting in an array of deep passive adsorptive wells whose hydraulic conductivity is higher than the surrounding soil. The design was based on COMSOL Multi-physics® simulations, which allow for the description of pollutant transport in groundwater and adsorption onto the barrier by means of a 2D model solved using a finite element approach. Based on a hydrological and geotechnical characterization of the entire polluted aquifer, the design and optimization of PAB-D parameters (location, orientation, number of wells and dimensions) were defined. The influence of hydraulic conductivity and dispersivity on the total number of wells for a complete aquifer remediation was investigated. Finally, a comparison with a continuous barrier (PAB-C), i.e. a wall of adsorptive material, in terms of total adsorbing material needed, is presented

"Dual-use value of network partitioning for water system management and protection from malicious contamination"

This paper considers the introduction of a contaminant into a water supply system using a backflow attack. The recent development of techniques for water network sectorization, aimed at improving the management of water systems, is also an efficient way to protect networks from intentional contamination and to reduce the risk of the dangerous effects of network contamination. Users can be significantly protected by isolated district meter areas (i-DMAs) in the water network and the closing of the gate valves by a remote control system to implement such i-DMAs in cases of malicious attacks. This study investigates the effects of different approaches for water network partitioning and sectorization to protect networks using a technique for designing i-DMAs that is compatible with hydraulic performance and that is based on graph theory and heuristic optimization. For this analysis, the introduction of cyanide through a backflow attack was assumed. The methodology was tested on a large water network in Mexico and displayed good protection from a malicious attack