Feasibility study of using thermal power of wastewater
for improving the efficiency of wastewater treatment facilities operation

Summary

A cost effectiveness analysis of using a system for recovering the thermal power of effluent for heating incoming wastewater to enhance the biological treatment process, as well as for heating the premises of wastewater treatment facilities was conducted. With account of the energy cost in the Republic of Bashkortostan, the operating and capital costs of the proposed method for arranging the heating of wastewater treatment facilities with two alternative options: using gaseous fuel (a block-type gas boiler house) and electric heating devices were estimated. The pay-back period was determined using the overhead cost equivalence method for the proposed design options. The energy efficiency was calculated based on the annual fuel and energy consumption expressed in tons of fuel equivalent. It was shown that the wastewater heating system using a heat pump requires the lowest operating costs (RUB 6.9 to heat 1 m³ of wastewater by 10°C, or RUB 1.3 million per year). The system is also the most energy- and cost-effective since it consumes the minimum fuel equivalent and provides for reducing the cost of expensive primary energy resources by 127 tons of fuel equivalent per year.

Key words

sewerage treatment facilities , heat pump , power efficiency , secondary thermal energy , recovery , pay-back period