Suitability of aluminium-based water treatment sludge (WTS), a waste product from water treatment facilities, was assessed for removal of heavy metals from an electroplating wastewater which had high concentrations of copper and chromium along with other heavy metals. Batch tests with simulated wastewater in single-and multi-metal solutions indicated the influence of initial pH and WTS dose on removal of six metals namely Cu(II), Co(II), Cr(VI), Hg(II), Pb(II) and Zn(II). In general, removal of cationic metals such as Pb(II), Cu(II) and Zn(II) increased with increase in pH while that of anionic Cr(VI) showed a reduction with increased pH values. Tests with multi-metal solution showed that the influence of competition was more pronounced at lower WTS dosages. Column test with diluted (100 times) real electroplating wastewater showed complete removal of copper up to 100 bed volumes while chromium removal ranged between 78-92%. Other metals which were present in lower concentrations were also effectively removed. Mass balance for copper and chromium showed that the WTS media had Cu(II) and Cr(VI) sorption capacities of about 1.7 and 3.5 mg/g of dried sludge, respectively. The study thus indicates that WTS has the potential to be used as a filtration/adsorption medium for removal of metals from metal-bearing wastewaters.

Intermittent Water Supply (IWS) is prevalent in most developing countries. Specifically, in India, IWS is existent throughout the country. Many studies focus on documenting the effects of IWS, and rarely the drivers of the IWS regime are studied. In this study, a systematic literature review was conducted on IWS studies around the globe. The various causes for IWS were documented. Then, by studying India's typical water supply system (WSS) configuration, the vicious cycle of IWS in India is discussed. Further, the drivers of IWS were identified and elaborated with the causing mechanisms. This knowledge will help devise strategies and solutions for improving the IWS in India and other developing countries with similar socio-economic conditions.

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The planning and design of water networks in water supply systems are primarily based on demand-driven modeling. The prevailing design provisions, such as minimum diameter, lead to oversizing of the water network, affecting operation. In upstream balancing reservoirs, outflow due to the water transmission network's excessive withdrawal capacity surpasses the available inflow causing flow starvation under intermittent water supply. This flow starvation causes partial flow in the downstream vicinity and forms a standing water column in the balancing reservoir's immediate downstream pipe. Traditional modeling approaches cannot simulate the piped network performance under this phenomenon due to their inability to model partial flow. Hence, a novel modeling approach is developed using a tank with an irregular cross-section, which integrates the hydraulic performance of the tank and the downstream pipe. Additionally, a reservoir and control valve represent the water withdrawal mechanism at the downstream reservoir. The proposed modeling approach simulates performance of a flow-starved water transmission network. A case study based on a real network is used to illustrate the robustness of the proposed approach. The developed modeling approach can serve as a management tool to devise operation schedules, helping better manage the operations of the water networks.

A Water Transmission Network (WTN) conveying raw water from a source to the Water Treatment Plant (WTP) is often pumped supply. Pumped supply-based networks have more energy consumption, water hammer, and high operation and maintenance compared to gravity systems. The present study reports the application of a Shaft in WTN for improving the efficiency of the pumping system. The Shaft is a hydraulic isolation structure based on a similar hydraulic principle as Break Pressure Tank (BPT). The benefits of using Shaft are quantified based on the two case studies from Maharashtra, India. The impact of Shaft on the WTN is reported using energy grade lines, energy performance indicators, and life cycle energy cost. In addition to the reduction in energy consumption, from the case studies, it is shown that the system’s carrying capacity could be increased by using the Shaft at an appropriate location in WTN. Overall, a Shaft provides operational flexibility to the operators, improving the efficiency of the system.