Aluminium Residuals

Optimum control of coagulation pH is essential in maintaining low aluminium residuals. Aluminium Sulphate can be used successfully in the pH range 6-7 and acid or alkali is often used for effective control. Doses of sulphuric acid can be high and uneconomic in hard water areas where raw water pH can be in the range 7.5-9. In these cases, Aqualenc G10 is recommended where aluminium residuals can be minimised at a coagulation pH of 7.5 which can offer savings in acid, alkali and sludge by-product levels.