Performance Monitoring and Evaluation of Sewage Treatement Plants Based on UASB-Facultative Pond

Abstract

Anaerobic treatment of municipal wastewater has recently gained worldwide attention due to its effectiveness, low cost, and low energy requirements The UASB has been considered to be the most attractive reactor system due to its simplicity and low operation cost. UASB reactors alone may not be sufficient to treat the sewage to the desired level and compliance with the applicable effluent standards, so effluent from UASB needs further treatment. The main role of the further treatment is to complete the removal of organic matter, as well as to remove the constituents little affected by the anaerobic treatment, such as nutrients and pathogenic organisms. The UASB and polishing pond configuration has been monitored and evaluated at six STPs in operation under the Satluj River Action Plan for one year period on monthly basis.studied in this dissertation work. The STPs in question are designed, commissioned and operated mainly for the removal or reduction of total suspended solids, BOD, COD and the coliform count (chlorination)from the sewage being treated. In these STPs even nutrients get coincidentally removed. Hence the performance evaluation has been carried out for BOD and COD removal, TSS, MPN and nutrients against the STP.BOD and COD have been the design parameters for the STP. Removal of the parameters TSS, nutrients and coliform count were actually evaluated in order to know how the performance of UASB and polishing pond based STP with that experienced elsewhere. Performance evaluation also involved comparison of the actual performance against the design performance and the estimated performance of the STP. The performance monitoring and evaluation study of the six STPs has shown that average removal efficiency for BOD, COD, TSS and total nitrogen (over one year period and over the six STPs) of the treated effluent were 70%, 69%, 68%, 12.8%. Excepting for MPN, if not for the role played by the algal cells in the treated effluent, the treatment processes are satisfactory indicating that plants are working properly. This has been the case despite use of chlorination in one of the STPs.