Assessment of an integrated tire-derived rubber media-fixed biofilm reactor (TDR-FBR) and sand column filter (SCF) for wastewater treatment at low temperature

Due to the shortage of fresh water and extensive discharge of wastewater into aquatic environment, the present research work aimed to evaluate the wastewater treatment efficiency of an integrated tire-derived rubber media-fixed biofilm reactor (TDR-FBR) and sand column filter (SCF) at low temperature (5°C–15°C). Wastewater was continuously re-circulated in TDR-FBR for 48 h at a flow rate of 80 ± 2 mL/min for 120 d. A substantial reduction in the average concentration of different pollution indicators, such as biochemical oxygen demand (BOD5, 92.7%), chemical oxygen demand (COD; 93.8%), total dissolved solids (TDS, 77.2%), phosphates (PO43–, 42.2%), sulfates (SO42–, 74.9%), nitrates (NO3–, 39.7%), nitrites (NO2–, 31.7%) and fecal coliform (80.9%) was achieved during 48 h of operational period through TDR-FBR. Subsequently, TDR-FBR effluent was further passed through SCF system and more than 95% of BOD5 and COD removal was observed. While, 83.6%, 46.6%, 77.8%, 55.9%, 65.8% and 99.4% reductions were noticed in TDS, PO43–, SO42–, NO3–, NO2– and pathogenic indicators, respectively. However, increase in the concentrations of dissolved oxygen (DO) from 1.5 to 6.9 mg/L was noticed after the sequential treatment in TDR-FBR and SCF system. Moreover, cytotoxicity analysis of treated effluent on brine shrimp (Artemia salina) showed that TDR media has no hazardous effects on aquatic ecosystem. It can be concluded that this hybrid TDR-FBR and SCF system has potential for large-scale applications for small communities in the developing countries.