Single step innovative process for municipal wastewater treatment in tourist areas

This paper reports the results obtained during a pilot experimentation aimed at testing the effectiveness of an innovative compact biological system for treating municipal wastewater in tourist areas. The results obtained after a long term operation have shown that the proposed system is able to assure average removal efficiencies higher than 90% for COD, total suspended solids, TKN and ammonia independently of the influent concentration values. Furthermore, the plant showed a high degree of operation flexibility and stability in response to the organic load variations occurring in tourist areas. High nitrogen removal efficiencies (80%, on average) were also achieved thanks to the establishment of simultaneous nitrification-denitrification process favoured by the plant's high biomass concentration and operating conditions. Finally, he plant system was characterized by an excess sludge production 80% lower than that of conventional biological systems operating without a primary clarifier. An acceptable level of stabilization of excess sludge was also obtained so that a further stabilization process was no longer required.