Pharmaceuticals are a group of bioactive compounds used to treat various diseases in humans and animals. Among these, diclofenac (DCF) and carbamazepine (CBZ) are most commonly used as analgesics and anticonvulsants. To fulfill the current demand, such pharmaceuticals are produced in a range of several thousand tons. Their high production causes their release in different water bodies leading to the deterioration of the water quality and causing ecotoxicity to several non-target organisms. Classical wastewater treatment plants show their lower removal efficiency. So, the development of new methods by combining older techniques is therefore required to eliminate these residues. To achieve this, the first objective of this study was to evaluates the efficacy of the non-pathogenic bacterial strain Bacillus subtilis BMT4i for removing DCF and CBZ, from an aqueous solution. For this, a series of batch experiments were conducted by keeping parameters similar to wastewater effluent to investigate the biodegradation of B. subtilis BMT4i in removing PhACs in real scenarios. Further, the viable bacteria were allowed to immobilize on activated carbons, and a comparative removal study was performed under both batch and column studies. The study showed that around 67% and 50% of DCF and CBZ were removed within 72 h when PhACs were supplied as the sole carbon source. Moreover, in co-metabolism with other carbon and nitrogen sources, the percentage removal was enhanced by 20-30%. Further, B. subtilis BMT4i were immobilized on two activated carbons i.e., ACEco, and ACDarco prepared from coconut shells and coal so that the composite could directly be used as a bioreactor. The biofilm formation over ACs was confirmed by scanning electron microscopy and Fourier-transform infrared spectroscopy. The results obtained with batch experiment showed over 85-100% removal of both PhACs in a short duration of 2 h. Moreover, the column studies revealed that around 60-77% of 1 mg/l PhACs were removed by passing over 2 L of PhACs contaminated water. Overall, the current study confirms that the B. subtilis BMT4i/ACs composite shows promising performance for removing selected PhACs from water. Hence, the synthesized composite is appropriate for extensive usage in treating wastewater containing PhACs contaminant to protect public health. Non-pathogenic bacteriumBacillus subtilisBMT4i was selected from the removal of pharmaceutical contaminants.A novelB. subtilisBMT4i/ACs composite materials were prepared by immobilizing viable cells over activated carbon.TheB. subtilisBMT4i/ACs composite shows over 100 % and 99 % removal of diclofenac and carbamazepine within 2 hours of contact time.
