MEMBRANE BIOREACTORS FOR WATER PROTECTION IN KASHKADARYA PROVINCE, UZBEKISTAN
Abstract
The Kashkadarya region of Uzbekistan is experiencing significant water ecosystem degradation due to the discharge of 7 million m³/year of inadequately treated wastewater, resulting in elevated mineralisation, organic/microbiological pollution, and eutrophication. Climate change, typified by a 75% glacier loss within a 15-year timespan, has led to a marked intensification of water scarcity. The present study assesses membrane bioreactor (MBR) technology for sustainable wastewater reuse. MBRs have been shown to remove 97–98% of organic pollutants (BOD5 < 6 mg/L), thereby preventing 1,416–2,511 t/year of organic matter and 220–365 t/year of nitrogen from entering the river. In addition, they achieve >99.9% pathogen removal, ensuring safe irrigation. Notwithstanding the fact that capital costs are 13–15% higher than those of conventional systems (645 vs. 570 million USD), resulting in a financial net present value (NPV) of –670 million USD, inclusive of 149 million USD in ecosystem benefits, the socio-economic NPV is nevertheless –520 million USD. It is posited that MBRs, with government support ranging from 35 to 40 per cent, may offer the most viable solution for regions experiencing water scarcity.