Improving the Efficiency of the Biological Treatment of Hospitals' Wastewater by Using MBBR with K1 and K3 Biofilm Carriers

Abstract

The performance of a moving bed biofilm reactor (MBBR) process was investigated using two different types of plastic carriers: K1 and K3, thereby enhancing the efficacy of biological treatment through biofilm development. The K3 carrier's geometric form was selected to reduce clogging and allow a simpler flow of organic matter and oxygen. Its internal openings are more homogeneous than those of the K1 carrier, and its specific surface area is greater than that. Laboratory-scale moving bed biofilm reactors were constructed from two identical volumes of a split 15L MBBR system. K1 carriers serviced one volume, while K3 carriers serviced the other with a 45% fill rate. A base aeration system provided oxygen, and automated sensors continuously monitored pH and temperature. After a period of acclimation for biofilm development, performance data were quantified and analyzed under standardized methods at steady-state. The results reveal that the K3 conveyor exceeded the K1 in all major performance standards. K3 eliminated 86% of the chemical oxygen demand (COD) and 81% of the biological oxygen demand (BOD), compared to 83% and 74%, respectively, for K1. In addition, K3 eliminated more ammonia (NH₃), 85% compared to K1, 72%, and eliminated 72% of K1 and 82% of all the total suspended solids (TSS). Taking all the parameters into consideration, the heightened efficiency of the K3 conveyor is mainly a result of its enhanced flow dynamics and biofilm adhesion characteristics. These results suggest that K3 can be utilized as a substitute for installed treatment systems or implemented in newly built wastewater treatment plants. Analyzing carrier composition on lifespan and financial efficiency, along with integration of K3 with emerging treatment technologies such as membrane filtration and ultraviolet disinfection, will be beneficial for future research work. This research assists in the development of more sustainable and efficient wastewater treatment processes.