Chemical Dosing System

The Environment Agency are increasingly imposing restrictions on the levels of phosphorous in the discharge from sewage treatment plants. When sewage is treated biologically, some of the phosphate is utilised by the bacteria. However,  to ensure final effluent levels are below 2 mg/l, suitable chemical reagents are added to assist in the precipitation of the excess phosphates via a dosing unit.

WPL  provide proven technology utilising bunded chemical storage and dosing pumps linked into a feedback control loop to ensure stringent Phosphorous standards are met and limiting the chemical dosing to ensure over-dosing is avoided.

WPL Dosing Units are dual channelled pH controllers providing either relay or proportional pulse outputs to drive chemical metering pumps.

Programmable features make it the most adaptive pH controller available. These all have manual stroke length adjustments which allow their output to be adjusted between 10 to 100%. There are also various sizes available ranging from 0.3 to 14.0 l/hr which covers all sewage treatment plant requirements.


WPL can bespoke chemical dosing units to fit requirement. Example footage below is a WPL chemical dosing solution for the WPL Disolved Air Floatation (DAF) at Farne Salmon and Trout Limited