title: Evaluation of different wastewater treatment processes and development of a modified attached growth bioreactor as a decentralized approach for small communities.
abstract: This study was undertaken to evaluate the potential future use of three biological processes in order to designate the most desired solution for on-site treatment of wastewater from residential complexes, that is, conventional activated sludge process (CASP), moving-bed biofilm reactor (MBBR), and packed-bed biofilm reactor (PBBR). Hydraulic retention time (HRT) of 6, 3, and 2 h can be achieved in CASP, MBBR, and PBBR, respectively. The PBBR dealt with a particular arrangement to prevent the restriction of oxygen transfer efficiency into the thick biofilms. The laboratory scale result revealed that the overall reduction of 87% COD, 92% BOD₅, 82% TSS, 79% NH₃-N, 43% PO₄-P, 95% MPN, and 97% TVC at a HRT of 2 h was achieved in PBBR. The microflora present in the system was also estimated through the isolation, identification, and immobilization of the microorganisms with an index of COD elimination. The number of bacterial species examined on the nutrient agar medium was 22 and five bacterial species were documented to degrade the organic pollutants by reducing COD by more than 43%. This study illustrated that the present PBBR with a specific modified internal arrangement could be an ideal practice for promoting sustainable decentralization and therefore providing a low wastage sludge biomass concentration.
authors: Department of Biological Sciences, Faculty of Agriculture, Science and Technology, North-West University, Mafikeng Campus, Private Bag X2046, Mmabatho 2735, South Africa.
authors: Shohreh
authors: S
authors: Azizi
authors: Alireza
authors: A
authors: Valipour
authors: Thami
authors: T
authors: Sithebe
mesh_terms: D000362:Agar / Q000737:chemistry; D018441:Biofilms; D057919:Biological Oxygen Demand Analysis; D018533:Biomass; D019149:Bioreactors; D004867:Equipment Design; D059013:Microbial Consortia; D009930:Organic Chemicals / Q000737:chemistry; D010100:Oxygen / Q000378:metabolism; D012722:Sewage; D013997:Time Factors; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater; D014871:Water Microbiology; D014874:Water Pollutants, Chemical / Q000302:isolation & purification* / Q000378:metabolism; D018508:Water Purification / Q000379:methods*
chemical_list: D000362:Agar; D009930:Organic Chemicals; D010100:Oxygen; D012722:Sewage; D062065:Wastewater; D014874:Water Pollutants, Chemical