2.1 Preparation of inoculum
The hydrogen producing anaerobic sludge containing mixed microflora was collected from the bottom of the anaerobic pond located at Felda Palm Oil Industry, Lepar Hilir, Gambang, Malaysia. To enrich the sludge with hydrogen producing bacteria and inhibit the bioactivity of methanogens, the sludge was heat treated at 90°C for 60 minutes [21]. The treated anaerobic sludge was used as inoculum for the hydrogen production. The acclimated inoculum has a 4.6 g-SS/L mixed liquor suspended solids (MLSS) and 5.6 g-VSS/L of mixed liquor volatile suspended solids (MLVSS). The heat-treated sludge was gradually acclimatized with POME in order to develop a stable microbial community. The acclimatized sludge was operated by …show more content…
The experiments were carried out in triplicate at initial concentrations of 25, 50 and 75 g-COD L-1. Additionally, to test the inoculum quality, positive controls with 25 g L-1 of cellulose instead of POME samples were also included for observation. When the hydrogen production ceased, the serum bottles were opened and another 150 grams of anaerobic digestion sludge was introduced into the reactors and incubated at 37°C for 45 days in order to evaluate the methane production. The bottles were manually stirred every day during the first 5 days. This was continued for the rest of the experiment duration. Biogas production was determined using water replacement method [24]. Biogas composition in the headspace of the bottles was monitored by GC-TCD using the method proposed by Sompong et al. …show more content…
The argon was used as a carrier gas with flow rate and pressure were maintained at 50 ml min-1 and 6 kg/cm2 respectively. The temperature of the column was 100°C, the injection and detection temperatures were 120 °C. The concentrations of H2, CH4, CO2 and N2were determined using a 3-point calibration with standard gas (GL Sciences). A gas chromatograph connected to flame ionization detector (FID) Stabilwax -DA capillary column (30 m ×0.53 mm ID, Resteck, USA) was used to measure the contents of VFAs and the alcohol. Helium was used as another carrier gas with the flow rate of 40mlmin-1. The heat-treated sludge was mixed thoroughly using the vortex [G-560 Scientific Industries, USA] prior to COD test, carbohydrate test and protein assay. The COD in the sludge was measured using spectrophotometer at 620 nm according to the Zhu et al. [11]. The carbohydrate concentration was estimated by the phenol sulphuric acid method, using glucose as a standard [26]. The protein content was analysed using the Lowry protein assay rapid kit, (Wako Co, USA). The NH4+ –N and total nitrogen (TN) and were determined by an auto-analyser TrAACs 8000 using a colorimeter to detect colour changes in the analytes (Bran + Luebbe K.K., Japan). The
The hydrogen producing anaerobic sludge containing mixed microflora was collected from the bottom of the anaerobic pond located at Felda Palm Oil Industry, Lepar Hilir, Gambang, Malaysia. To enrich the sludge with hydrogen producing bacteria and inhibit the bioactivity of methanogens, the sludge was heat treated at 90°C for 60 minutes [21]. The treated anaerobic sludge was used as inoculum for the hydrogen production. The acclimated inoculum has a 4.6 g-SS/L mixed liquor suspended solids (MLSS) and 5.6 g-VSS/L of mixed liquor volatile suspended solids (MLVSS). The heat-treated sludge was gradually acclimatized with POME in order to develop a stable microbial community. The acclimatized sludge was operated by …show more content…
The experiments were carried out in triplicate at initial concentrations of 25, 50 and 75 g-COD L-1. Additionally, to test the inoculum quality, positive controls with 25 g L-1 of cellulose instead of POME samples were also included for observation. When the hydrogen production ceased, the serum bottles were opened and another 150 grams of anaerobic digestion sludge was introduced into the reactors and incubated at 37°C for 45 days in order to evaluate the methane production. The bottles were manually stirred every day during the first 5 days. This was continued for the rest of the experiment duration. Biogas production was determined using water replacement method [24]. Biogas composition in the headspace of the bottles was monitored by GC-TCD using the method proposed by Sompong et al. …show more content…
The argon was used as a carrier gas with flow rate and pressure were maintained at 50 ml min-1 and 6 kg/cm2 respectively. The temperature of the column was 100°C, the injection and detection temperatures were 120 °C. The concentrations of H2, CH4, CO2 and N2were determined using a 3-point calibration with standard gas (GL Sciences). A gas chromatograph connected to flame ionization detector (FID) Stabilwax -DA capillary column (30 m ×0.53 mm ID, Resteck, USA) was used to measure the contents of VFAs and the alcohol. Helium was used as another carrier gas with the flow rate of 40mlmin-1. The heat-treated sludge was mixed thoroughly using the vortex [G-560 Scientific Industries, USA] prior to COD test, carbohydrate test and protein assay. The COD in the sludge was measured using spectrophotometer at 620 nm according to the Zhu et al. [11]. The carbohydrate concentration was estimated by the phenol sulphuric acid method, using glucose as a standard [26]. The protein content was analysed using the Lowry protein assay rapid kit, (Wako Co, USA). The NH4+ –N and total nitrogen (TN) and were determined by an auto-analyser TrAACs 8000 using a colorimeter to detect colour changes in the analytes (Bran + Luebbe K.K., Japan). The