Sewage treatment is a difficult urban problem, is expensive and often unsatisfactorily delivered especially in India. Effective but simple technology has been developed by IITB (Prof.HSShankar, ChE Dept along with his students) that uses the ‘green’ Soil Bio-Technology (SBT). The Soil bio-Technology uses a carefully prepared and maintained soil bed as a highly aerated reactor containing bio-organisms for (i) filtering the suspended matter and its bioconversion to odourless bio-fertilizer, (ii) converting dissolved organics by adsorptionand oxidation/bioconversion, and (iii) oxidizing the dissolved inorganic substances leading to precipitation and bioconversion. The basic control apparently is to manage the soil chemistry with appropriate mineral based additives to maintain a near neutral pH andto keep it highly porous for good aeration. The root systems of the plants on the bed helpin keeping the soil porous and have a biotic relationship with the organisms.
