Biological treatment of fish processing wastewater: A case study from Sfax City (Southeastern Tunisia)
Meryem Jemli
,
Fatma Karray
,
Firas Feki
,
Slim Loukil
,
Najla Mhiri
,
Fathi Aloui
,
Sami Sayadi
DOI:10.1016/j.jes.2014.11.002
Received July 05, 2014,Revised November 27, 2014, Accepted , Available online April 23, 2015
Volume 27,2015,Pages 102-112
The present work presents a study of the biological treatment of fish processing wastewater at salt concentration of 55 g/L. Wastewater was treated by both continuous stirred-tank reactor (CSTR) and membrane bioreactor (MBR) during 50 and 100 days, respectively. These biological processes involved salt-tolerant bacteria from natural hypersaline environments at different organic loading rates (OLRs). The phylogenetic analysis of the corresponding excised DGGE bands has demonstrated that the taxonomic affiliation of the most dominant species includes Halomonadaceae and Flavobacteriaceae families of the Proteobacteria (Gammaproteobacteria class) and the Bacteroidetes phyla, respectively. The results of MBR were better than those of CSTR in the removal of total organic carbon with efficiencies from 97.9% to 98.6%. Nevertheless, salinity with increasing OLR aggravates fouling that requires more cleaning for a membrane in MBR while leads to deterioration of sludge settleability and effluent quality in CSTR.
