Utilization of electrocoagulation-treated spent wash sludge in making building blocks

Minimization, utilization and disposal of industrial waste are very important from the environmental esthetic point of view. Sludge generated during the treatment of distillery spent wash by electrocoagulation process is highly complex in nature and requires proper disposal. In this context, the present study was conducted to employ the electrocoagulation-generated sludge as a partial replacement of cement while manufacturing the non-constructional building blocks. Various physiochemical and thermo-gravimetric characterization studies have been carried out on electrocoagulation-generated sludge and cement. Mortar specimens with different proportions of sludge ranging from 0 to 15 % by weight of cement were tested for density, compressive strength and leachability of heavy metals by standard method. Results from the analysis showed that the cement-based solidification of EC sludge reduces the heavy metal concentration in the leachate from cement–sludge mortars compared to the EC sludge alone. Reduction in the compressive strength of mortar with 7.5 % substitution of cement by EC sludge was < 5 % against the control mortar (without sludge), thereafter the reduction was substantial. The optimum percentage of sludge that can replace the cement with marginal change in the physiochemical properties is found to be 7.5. This can be used in the manufacturing of the non-constructional building material within the industry for their different types of usages such as paving, pot making and fencing of garden without affecting the environment.

Keywords
Electrocoagulation sludge; Compressive strength; Leachability; Thermal degradation