Enhancing simultaneous electricity production and reduction of sewage sludge in two-chamber MFC by aerobic sludge digestion and sludge pretreatments

Evaluation of electricity production from alkaline pretreated sludge using two-chamber microbial fuel cell

“…The collected sludge samples were first filtered using a 40-mesh sieve to remove the larger particles and allowed to settle by gravity for approximately 1 h. The sediments were stored at 4 • C before use. The sewage sludge was adjusted to the appropriate concentration and then alkaline pretreated as discussed previously [19]. Some characteristics of the sewage sludge, alkaline pretreated sludge, anaerobic sludge and sludge mixture in the anode chamber are summarized in Table 1.…”

“…The MFC was constructed as described previously using a 5 cm 2 proton exchange membrane (Nafion117) [19]. The 4 cm × 6 cm × 0.5 cm anode and 4 cm × 6 cm × 0.1 cm cathode were made of carbon felt (Sanye Carbon Co., China) and carbon paper without wet proofing (Toray Co., Japan), respectively, and were located 14 cm apart.…”

“…MFCs can produce electricity from a variety of materials including organic wastes [12], such as brewery wastewater [13], starch processing wastewater [14], paper recycling wastewater [15], and sludge [9,[16][17][18][19][20]. The electricity production from sewage sludge is lower.…”

“…These methods include alkaline pretreatment [19,21,22], thermal pretreatment [19], ultrasound pretreatment [21], enzyme addition [23], biocathode [19,20], aerobic digestion [19], and so on. Our previous study [19] showed that electricity production from sewage sludge could be increased by thermal and especially alkaline pretreatment, and the voltage outputs and power densities were increased from 0.28-0.31 V and 17.3-21.2 mW/m 2 to 0.41-0.43 V and 36.8-40.1 mW/m 2 , respectively. Yang et al [23] studied the effect of additional enzymes on the electricity production of sludge and found that both neutral protease and ␣-amylase could enhance electricity production using sludge with an electricity density enhancement to 507 and 700 mW/m 2 , respectively, when the enzyme concentration was 10 mg/gTS.…”

“…Alkaline pretreatment has therefore been studied by several researchers [19][20][21][22] and is believed to be a potential method for enhancing electricity production. Jiang et al [21] found the power output increased from 10.3 to 12.5 W/m 3 by using combined ultrasonic and alkaline sludge pretreatment.…”