Atcharaporn Wareewanit. Anaerobic treatment and biogas production of tuna-processing wastewater by using a conventional anaerobic digester . Master's Degree(Appropriate Technology for Resources and Environmental Development). Mahidol University. : Mahidol University, 2003.
Anaerobic treatment and biogas production of tuna-processing wastewater by using a conventional anaerobic digester
Abstract:
The objective of this research was to determine the efficiency in COD, BOD, TVS
and TS removal as well as biogas production from the tuna-processing wastewater by using
a conventional anaerobic digester at the hydraulic retention times of 20, 30, 35 and 40 days.
The results presented that the efficiency in COD removal at the hydraulic retention
times of 20, 30, 35 and 40 days was 48.00 %, 81.33 %, 77.71 % and 71.74 %, respectively,
whereas, that in BOD removal was 52.22 %, 90.57 %, 89.47 % and 85.55 %, at the same
respective retention times. As for TVS removal, the efficiency was 40.73 %, 68.25 %,
64.65 % and 60.81 %, while for TS removal, it was 22.99 %, 35.79 %, 35.02 % and
33.35 %, respectively. The amount of biogas production at the hydraulic retention times of
20, 30, 35 and 40 days was 0.127, 0.201, 0.111 and 0.149 m3/kgCODremoved or the equivalent
of 0.180, 0.490, 0.258 and 0.297 m3
biogas/m3
feeding wastewater, respectively. Furthermore, the
methane contents of the biogas were respectively 29.11 %, 44.84 %, 44.52 % and 35.47 %
at the same retention times. In all cases, the digester could be operated without addition of
nutrients.
These results clearly demonstrated that the suitable condition for operating the
system was a 30-day hydraulic retention time as this obtained the highest efficiency in
COD, BOD, TVS and TS removal which was 81.33%, 90.57%, 68.25% and 35.79%,
respectively, and produced the largest amount of biogas production of around
0.49 m3
biogas/m3
feeding wastewater with a methane content of 44.84 %.