Schwarzite-based 3D-printed carriers for enhanced performance of sequencing batch biofilm reactor (SBBR) for wastewater treatment

Abstract

The energy-efficient, green, and sustainable wastewater treatment using biofilm reactors is gaining a lot of attention. The efficiency of biofilm-based reactors (e.g., sequencing batch biofilm reactor (SBBR) and moving bed biofilm reactor (MBBR), etc.) can be further improved with the help of strong, highly active, and functionally engineered carriers. Here, Schwarzite-based 3D-printed biocarriers were prepared to obtain optimum mechanical properties and enhanced organics and nutrient removal efficiencies. The optimized carrier (L2) possesses the highest porosity (∼75%) and specific modulus of resilience and lowest bulk density among the other prepared structures (i.e., L1, L3, and L4). High porosity and specific surface area of the carriers promote enhanced growth of biomass with a total of 0.3 g biomass/carrier. The optimized biocarrier showed ∼95% chemical oxygen demand and ∼84% ammonium nitrogen removal efficiencies, which were attributed to its high specific surface area and porosity. The performance of SBBR with 3D-printed biofilm carriers having only a 15% fill ratio was compared and found better than the conventional K2 carriers used with a filling ratio of 50%. The high mechanical stability and specific surface area of the L2 biocarrier make it feasible to be used as a biofilm carrier, which may drastically reduce the number of carriers thereby directly reducing the cost.