An integrated system for agricultural wastewater treatment

Abstract

The treatment of agroindustrial wastewaters gives the possibility of noxious pollutant removal which otherwise would deteriorate the ecosystem even more. The construction and start-up of Integrated Systems for the treatment of such wastes allow the reuse of the treated effluents, with the consequent production of useful by-products. Biological processes for the adequate treatment of 300 m3/day of mixed animal and human wastewaters allow also the production of 1200 m3/day of biogas as an energy supplier and a source of CO2 for microalgae culture in a High Rate Algal Pond. On the other hand, it can be possible to recover the digested sludge as biofertilizer and low grade water useful for crop irrigation. The proposed Integrated System also provides the recovery of 8.3 g/m2/d of algal biomass suitable for animal consumption and the removal of an important amount of noxious pollutants with an average efficiency of 80–98% (COD basis).