Integration of UASB and down flow hanging non-woven fabric (DHNW) reactors for the treatment of sewage water

The present study introduces a new technique using combined up-flow anaerobic sludge bed (UASB) reactor followed by innovative downflow hanging non-woven fabric (DHNW) reactor for treating of sewage. The packing material used in this study could be produced from waste plastic bottles, thus huge part of solid waste can be reduced, recycled and reused in wastewater treatment plant to produce treated reusable effluent. Both packed and classical UASB reactors (in parallel mode) were used for the treatment of sewage. The UASB (packed and classical) were operated at two hydraulic residence time (HRT). The quality of the packed UASB (P-UASB) effluent was found to be better than that of the classical UASB reactor. Consequently, the effluent of the P-UASB reactor was fed directly to the DHNW reactor. The source of wastewater was the domestic wastewater from Zenein’s wastewater treatment plant. The performance of the combined P-UASB/DHNW showed reduction of COD, BOD and TSS from 441, 309 and 187 to 41, 21 and 17 mg/l, and from 386, 293 and 192 mg/l to 45, 30 and 19 mg/l, at HRT 6 h and 5 h, respectively. While, the fecal coliform (FCs) count was reduced from 3.8×10 7 to 5×10 5 MPN/100 ml and from 3.6×10 7 to 7×10 5 MPN/100 ml at HRT 6 h and 5 h, respectively. Consequently, the effluent needs disinfection for safe reuse in irrigation. The results indicated that polyethylene terephthalate (PET) spun-bond non-woven fabric can offer a reliable and simple solution as well as efficient packing material for wastewater treatment.