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Water Distribution
Published in Subhash Verma, Varinder S. Kanwar, Siby John, Environmental Engineering, 2022
Subhash Verma, Varinder S. Kanwar, Siby John
Common types of storage facilities include ground storage, underground reservoirs, elevated tanks and standpipes. An underground storage reservoir built as part of a water treatment plant is called a clear well. An elevated storage tank’s main purpose is to maintain system pressure. Level switches control flow in and out of the tank. Hydropneumatic tanks are used for small-scale and individual household water systems. Storage reservoirs need to be protected against corrosion, contamination and vandalism. To maintain the quality of water, about two-thirds of the storage’s volume should be renewed every day. Procedures for operating reservoirs depend on the type of facility and the magnitudes of system demands. However, replenishing the reservoir after the peak demand period and maintaining system pressure should be the main consideration in any operation scheme.
Water Resources Systems Management Under Uncertainty – a Fuzzy Set Approach
Published in Slobodan P. Simonović, Managing Water Resources, 2012
Finally, particulate matter is removed using four gravity filters during the filtration process. The treatment is no longer split into two parallel streams as the water can be directed to any of the four filters. The filtered water is collected in the filtered water conduit underlying the filters, and flows into a clear-well and the on-site reservoir. Post-chlorination takes place in the conduit leading from the on-site reservoir to the high-lift pumping station. The high-lift pumping station delivers finished water through the transmission main to the terminal reservoir in St Thomas. It also delivers water to the secondary distribution system. A surge facility was constructed in 1994 to protect the transmission main from damage as a result of system transit pressure conditions during cycling of the high-lift pumps.
Microbial Breakthroughs in Changing Source, Treatment, or Supply Parameters
Published in Edwin E. Geldreich, Microbial Quality of Water Supply in Distribution Systems, 2020
The Western Pennsylvania Water Company Hays Mine plant presented an opportunity to study the alternative use of chlorine dioxide as the primary disinfectant.7 For this investigation, the routine practice (Table 7.12) was source water chlorination, potassium permanganate treatment, coagulation, settling, activated carbon filtration/adsorption, and free chlorine application in the clear-well. Later, the treatment train was modified (Table 7.12) to inject chlorine dioxide and potassium permanganate into the source water entering the coagulation basin. Free chlorine was applied as a secondary disinfectant in the clear-well prior to distribution. Chlorine dioxide dosage to the source water was 1.5 mg/l and contained less than 0.1 mg/l chlorine.
A study of the electrochemical and tribological properties of TiN/CrN nano-layer coating deposited on carburized-H13 hot-work steel by Arc-PVD technique
Published in Journal of Asian Ceramic Societies, 2021
Erfan Lotfi-khojasteh, Mohammad Sahebazamani, Hassan Elmkhah, Meisam Nouri, Omid Imantalab, Arash Fattah-alhosseini
The wear rate for the sample coated with TiN/CrN coating is the least between all three samples (Figure 8) and the worn surface of the sample (Figure 9(c)) is not clear well. In fact, the width of the track is very small, and from both optical and micrograph images, we can deduce that the track is very shallow. The average friction coefficient for the coated sample is the smallest between the samples. All these confirm the superiority of the TiN/CrN coated sample in resistance against wear. The coating creates a very hard layer on the sample, about 7 times harder than the substrate steel and about 2.5 times harder than the carburized surface. In addition, as discussed above, the coating layer makes a perfect bonding with the substrate underneath. Moreover, the nature of the TiN and CrN is different from the steel pin which makes the role of adhesion wear minor. These reasons provide the coated sample with an excellent resistance against sliding motion wear. Other researchers have attributed the improvement in the properties of CrN/TiN coatings to dense microstructure, increased residual compressive stress, and reduced grain size [8].