Solutions are sought for reducing the TDS levels of effluent discharge from ETP in an economical manner.
The manufacturing process of Iron Oxide from Ferrous Sulphate and Iron scrap generates 700 – 800 KL/day of acidic effluent (pH ~3.5) containing about 0.6-0.8% Ferrous Sulphate (8-35gm/l) and Sodium Sulphate (25-35 gm/l). This effluent is lime (Ca(OH)2) treated and as a result, we get the treated effluent ETP (Effluent Treatment Plant) discharge with about 8000-10000 ppm TDS. This has CaSO4 as a sludge, Na2SO4(8 g/l), and FeSO4 (3.1g/l).
A distillation process reduces the TDS to as low as 900 ppm but is very expensive. Thus, we are looking for a solution that will easily and economically bring down the TDS level of this effluent to below 1500 ppm. The installation costs and operating costs are critical for any solution.