Wastewater Chemical Storage & Control Systems

There are different types of chemicals whether in solid or liquid form employed for use in wastewater treatment plant for different steps and stages in the various unit operations. Each has its own individual purposes with some like coagulant, precipitation agent, sodium hydroxide 49% concentration, urea, Trisodium phosphate (TSP) being the most common. Some of these chemicals can either be corrosive in nature or a known irritant and hence having a proper chemical storage and control system is very important.

These chemicals can exist in different forms like slurry, liquid or solids with each serving its own purpose. Some, which are usually sent in concentrated form, were done in order to save cost on delivery and also to save precious storage space especially in small package plants or mobile system. Basically there are two different modes of feeding system going into the wastewater treatment plant depending on whether it is solid or liquid. For instance, coagulant, which can be delivered by the supplier in solid from, is generally converted into a solution while some can be turned into slurry before introduction into specific unit processes. For coagulant coming in as liquid form, which is highly concentrated, usually mixture of water is needed in order to dilute it prior to feeding.

A Dry Chemical Feed System is usually made up of a storage hopper, dilution tank complete with a pump or either the tank is located above high ground level to take advantage of gravity flow. In order to feed in the right amount of solution to the wastewater treatment process, usually either volumetric measuring cylinder or load cell weight system can be used for the purpose. For the dissolving or dilution operation, amount of water supply has to be controlled in order to create the right concentration.

A Liquid Feed System is generally similar just like the previous dry setup except that it requires high capacity of storage tanks. While there is no perfect installation, the idea towards having a usable and accurate control system depends on how well the system is designed to suit the application.

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