The level in the container goes above the operator settable dosing start level (SP1).The operator enables the dosing process from HMI / SCADA.The sequence of steps shall be as follows In Auto mode, PLC / DCS shall take care of the steps followed by the operator in manual mode. Once the sufficient dosing is done, operator shall manually stop the dosing pump and close the valve. The dosing pump shall continue to dose chemical at operator settable dose rate (l/h). If there is sufficient level in the container the operator shall manually open the valve and then enter the start command to Dosing Pump 1 or 2 and enter the required dosing rate (SP1) at HMI / SCADA. In manual mode, the operator shall manually observe the level in the container using the level instrument and probes displayed on HMI / SCADA. The operator has the facility to dose the chemical in Auto / Manual Modes from HMI / SCADA.

The outlet valve shall discharge the chemical into the point of location. The dosing pumps 1 & 2 shall operate in Duty / Standby mode in order to maintain the redundancy. It shall indicate the chemical contained in the container. The above typical dosing unit consists of a chemical container with Level Instruments & Switches. The valves at the outlet of dosing pumps are On/Off valves to regulate the flow of chemicals at the location. The dosing pumps fetched the required chemical from container with the help of actuators.

The container is equipped with level indicators so that it can be filled efficiently by observing the volume of chemical used. The location of dosing is mainly decided by chemical engineers or process engineers. The chemical dosing system mainly consists of a storage container, dosing pumps, level instruments, switches, and valves. pH neutralizers (Sodium Hydroxide / Caustic).The major chemicals used in wastewater treatment are

The environmental regulating bodies prescribe the exact quality of water to be discharged into main streams. If such water is discharged into the rivers, lakes, etc., there are high chances of threat to Human Life & Bio life as well. The main motto behind chemical dosing is Phosphate Removal & pH maintenance.ĭue to various chemical reactions & processes followed in industries, there are high chances of increasing the pH of used water. Chemical dosing is one of the most crucial processes in Wastewater Treatment.

I doser dose explanations