Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
584448 | Journal of Hazardous Materials | 2007 | 10 Pages |
Abstract
Biofilm configured system with sequencing/periodic discontinuous batch mode operation was evaluated for the treatment of low-biodegradable composite chemical wastewater (low BOD/COD ratio â¼0.3, high sulfate content: 1.75Â g/l) in aerobic metabolic function. Reactor was operated under anoxic-aerobic-anoxic microenvironment conditions with a total cycle period of 24Â h [fill: 15Â min; reaction: 23Â h (aeration along with recirculation); settle: 30Â min; decant: 15Â min] and the performance of the system was studied at organic loading rates (OLR) of 0.92, 1.50, 3.07 and 4.76Â kg COD/cum-day. Substrate utilization showed a steady increase with increase in OLR and system performance sustained at higher loading rates. Maximum non-cumulative substrate utilization was observed after 4Â h of the cycle operation. Sulfate removal efficiency of 20% was observed due to the induced anoxic conditions prevailing during the sequence phase operation of the reactor and the existing internal anoxic zones in the biofilm matrix. Biofilm configured sequencing batch reactor (SBR) showed comparatively higher efficiency to the corresponding suspended growth and granular activated carbon (GAC) configured systems studied with same wastewater. Periodic discontinuous batch mode operation of the biofilm reactors results in a more even distribution of the biomass throughout the reactor and was able to treat large shock loads than the continuous flow process. Biofilm configured system coupled with periodic discontinuous batch mode operation imposes regular variations in the substrate concentration on biofilm organisms. As a result, organisms throughout the film achieve maximum growth rates resulting in improved reaction potential leading to stable and robust system which is well suited for treating highly variable wastes.
Keywords
ORPdissolved oxygen (mg/l)Composite chemical wastewaterSBBROCRGACOLRHRTBODSDRDNAVSsdeoxyribonucleic acidRNAribonucleic acidBiofilmSuspended solidsTimehydraulic retention timeSEMVolatile suspended solidsOxygen consumption rateOrganic loading rateSequencing batch biofilm reactorOxidation reduction potentialCodGranular activated carbon
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Chemical Health and Safety
Authors
S. Venkata Mohan, N. Chandrasekhara Rao, P.N. Sarma,