%0 Journal Article
%T THE EFFECT OF THE SLUDGE RECYCLE RATIO IN AN ACTIVATED SLUDGE SYSTEM FOR THE TREATMENT OF AMOL'S INDUSTRIAL PARK WASTEWATER
%A BAHAR HOSSEINI
%A GHASEM NAJAFPOUR DARZI
%A MAEDEH SADEGHPOUR
%A MOSTAFA ASADI
%J Chemical Industry and Chemical Engineering Quarterly
%D 2008
%I Association of the Chemical Engineers
%X An activated sludge aeration tank and a sedimentation basin were used to treat Amol¡¯s industrial park effluents originating from all industrial units. A continuous system was implemented and the kinetic parameters were measured.The parameters such as rate constant, substrate utilization rate constant, yield and decay coefficient were 2.12 d-1, 232.4 mg l-1, 0.33 g/g of substrate and 0.096 d 1, respectively. The hydraulic retention times (HRT) were in the range of 9 to 27 h. The sludge recycle ratios in the range from 0.3 to 1 were considered. The COD removal, SVI and DO were determined and the optimal values were obtained. It was observed that at HRT of 16 h and the sludge recycle ratio of 0.85, the COD removal and SVI were 95 and 85 %, respectively. The sludge recycle ratio greater than 0.85 had no significant effect on the COD removal.
%K activated sludge
%K COD removal
%K industrial effluents
%K sludge recycle ratio
%K SVI
%U http://www.ache.org.rs/CICEQ/2008/No3/04_14%283%29_2008.pdf