PERFORMANCE EVALUATION OF MOVING BED BIOFILM REACTOR (MBBR) BASED WATER TREATMENT PLANT WITH RESPECT TO EMERGING CONTAMINANTS AND DISSOLVED ORGANIC MATTER

Abstract

In this study, the performance of Moving Bed Bio-film Reactor (MBBR) based water treatment plant (WTP) at Agra, India was monitored. Water Treatment Plant in Agra (U.P.), which operates on Attached Growth Airlift Reactor (AGAR) Moving Bed Biological Reactor (MBBR) technology, is considered one of the ultra-modern water works facility in the country. The plant takes it raw water input from the River Yamuna and the treatment is done so that the effluent water can be used as potable water. The performance was evaluated in terms of pH, turbidity, biochemical oxygen demand (BOD), chemical oxygen demand (COD), ammonia, Dissolved Organic Matter (DOM) as well as with respect to Emerging Contaminants removal at each unit process of the WTP. Experimental work was started from the month of May 2017. The grab samples were collected once in a month from each unit process of the treatment plant. The effluent BOD values were lower than the limit of detection while other parameters were following limits prescribed by WHO. The test results demonstrated that effluent water quality parameters were within prescribed limit of drinking water standards. The Work related to Emerging Contaminants was done using Solid Phase Extraction (SPE) as the sample cleanup process while the contaminants were identified using GC-MS (Gas Chromatography-Mass Spectrometry). Emerging Contaminants analysis was also done on Liquid Chromatography- Quadrupole-Time of Flight-Mass Spectrometer (LC-QTof-MS). The Emerging Contaminants that were identified includes diclofenac, Ibuprofen, Ketoprofen, Pyridine etc. The concentration range of these emerging contaminants was from 100 ng/l to 1500 ng/l. In total, 15 transformation products from ten parent compounds were tentatively identified, 4 of these transformation products were confirmed by reference standards. Nine of these TPs have been reported in the scientific literature as biodegradation products. A removal in range of 90-100% of these compounds were achieved in water treatment plant at Agra while for having an idea about dissolved organic matter in water fractionation studies using XAD8 and XAD4 resins were done. The result shown that major fraction of Dissolved Organic Matter (DOM) in Yamuna River was hydrophobic in nature i.e. 60-62 % of DOM. Also a comparative study was done with performance of a conventional water treatment plant located in Mathura on the basis of above water quality parameters. This comparison demonstrated the comparison of MBBR based WTP with conventional water treatment plant suggesting higher efficiency of MBBR based plant than conventional WTP. The study also suggests that there is need to upgrade the conventional technology used at Mathura WTP in view of improving water supply quality.