Water & Wastewater Treatment

Getting to Grips with… dosing pumps Dosing pumps are mission critical appliances that must operate reliably and efficiently, as the success of processes such as disinfection depend on achieving accurate dosing. Here, we look at some of the most important issues involved in operating and controlling these key pieces of equipment, from their consumption of chemicals and electricity to issues such as leaks or bursts which could have serious consequences The Knowledge Q: What are the main applications for dosing pumps in water and waste- water treatment? A: In municipal water treatment and wastewater treatment, dosing pumps are extensively used to add chemicals for chlorination (disinfecting harmful pathogenic microorganisms) for oxidation (assisting in aeration) and for pH correction or adjustment. Chemicals are also dosed to prevent corrosion and to make the water more stable. Other typical applications are when dosing pumps are used to add chemicals for flocculation and coagulation purposes to remove particulate, dissolved metals and organic matter. They can also add chemicals that will remove odour, to change the colour of the water, or simply to improve the taste. Chemicals dosed can also DOSING PUMPS q&A www.wwtonline.co.uk | WWT | JUNE 2017 | 31 HEIDI BERGER, BusIness DIrector, DosIng anD DIsInfectIon grunDfos remove lead from old pipes. these are some of the typical applications, but there are many other occasions where dosing pumps can be called upon, such as fluoridation and phosphate removal. The basic rule is that dosing pumps are an integral part of any and all water and wastewater treatment processes where chemicals need to be added. Q: What types of pump are appropri- ate for these tasks, and what are the considerations when choosing between them? A: Dosing pumps by definition are positive displacement pumps, and the most common types are diaphragm style, peristaltic or progressive cavity pumps. When choosing between these different designs, a

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