TY - JOUR
T1 - Combined anaerobic treatment of domestic wastewater and landfill leachate at psychrophilic temperatures
AU - Gomec, Cigdem Yangin
AU - Cifci, Deniz Izlen
AU - Ozturk, Izzet
AU - Kinaci, Cumali
PY - 2008
Y1 - 2008
N2 - The aim of this study was to investigate the influence of low temperature on a lab-scale continuous-flow Upflow Anaerobic Sludge Bed (UASB) reactor performance treating pre-settled raw sewage and leachate (1.0% by volume) mixture, without any additional heating. The mesophilic seed was acclimatized to low temperatures with synthetic wastewater characterizing raw sewage (HRT =12 h). The reactor was then fed with raw domestic wastewater (aver-age COD tot ≅ 235 mg/L) at the same HRT. Results indicated average CODtot, and CODsol removals of 59% and 32%, respectively (OLR=0.5 kg COD/m3.day), only with raw sewage feeding. During pre-settled sewage feeding, average CODtot, and CODsol removals were observed as 14% and 37%, respectively (OLR= 0.3 kg COD/m 3.day) at a HRT of 8 h. Low organic removals could be attributed to very dilute influent (weak strength) characteristics of both raw and pre-settled sewage. In the study, raw sewage and young landfill leachate (with 1.0% by volume) were mixed and pre-settled in order to increase the initial COD tot, to around 550 mg/L. Since raw sewage reflected a very weak strength character, the aim was to increase the influent organic concentration to a relatively medium strength character by leachate addition, before the psychrophilic UASB reactor was fed. Average CODtot, and COD sol removals improved and were obtained as 60% and 67% (OLR=1.3 kg COD/m3.day; HRT=10 h) respectively at room temperatures (15±3°C). Besides, average biogas production was calculated to be 0.25 m3/kg CODremoved.day with leachate addition, whereas almost no biogas productions were observed in the cases of either pre-settled or raw domestic sewage treatment. Apparently, low influent COD resulted in low substrate levels inside the reactor, and also in a low biogas production rate. Thus, anaerobic treatability performance based on COD removals was significantly affected by influent COD concentration rather than operational temperature.
AB - The aim of this study was to investigate the influence of low temperature on a lab-scale continuous-flow Upflow Anaerobic Sludge Bed (UASB) reactor performance treating pre-settled raw sewage and leachate (1.0% by volume) mixture, without any additional heating. The mesophilic seed was acclimatized to low temperatures with synthetic wastewater characterizing raw sewage (HRT =12 h). The reactor was then fed with raw domestic wastewater (aver-age COD tot ≅ 235 mg/L) at the same HRT. Results indicated average CODtot, and CODsol removals of 59% and 32%, respectively (OLR=0.5 kg COD/m3.day), only with raw sewage feeding. During pre-settled sewage feeding, average CODtot, and CODsol removals were observed as 14% and 37%, respectively (OLR= 0.3 kg COD/m 3.day) at a HRT of 8 h. Low organic removals could be attributed to very dilute influent (weak strength) characteristics of both raw and pre-settled sewage. In the study, raw sewage and young landfill leachate (with 1.0% by volume) were mixed and pre-settled in order to increase the initial COD tot, to around 550 mg/L. Since raw sewage reflected a very weak strength character, the aim was to increase the influent organic concentration to a relatively medium strength character by leachate addition, before the psychrophilic UASB reactor was fed. Average CODtot, and COD sol removals improved and were obtained as 60% and 67% (OLR=1.3 kg COD/m3.day; HRT=10 h) respectively at room temperatures (15±3°C). Besides, average biogas production was calculated to be 0.25 m3/kg CODremoved.day with leachate addition, whereas almost no biogas productions were observed in the cases of either pre-settled or raw domestic sewage treatment. Apparently, low influent COD resulted in low substrate levels inside the reactor, and also in a low biogas production rate. Thus, anaerobic treatability performance based on COD removals was significantly affected by influent COD concentration rather than operational temperature.
KW - Combined treatment
KW - Landfill leachate
KW - Psychrophilic temperatures
KW - Sewage
KW - UASB reactor
UR - http://www.scopus.com/inward/record.url?scp=57649188424&partnerID=8YFLogxK
M3 - Article
AN - SCOPUS:57649188424
SN - 1018-4619
VL - 17
SP - 1828
EP - 1832
JO - Fresenius Environmental Bulletin
JF - Fresenius Environmental Bulletin
IS - 11 A
ER -
