Improvement of upflow anaerobic sludge bed performance using chitosan.
Chitosan, with a degree of deacetylation of 85% and a molecular weight of 2.5 x 10(5) Da, yielding high flocculation efficiency (85 to 100% flocculation) and a broad flocculation region (2 to 45 mg/g suspended solids), was selected for accelerating granulation in a 30-L upflow anaerobic sludge bed (UASB) used to treat wastewater from a tropical fruit-processing industry. Compared with other studies, smaller amounts of chitosan were applied (two injections with 2 mg chitosan/g suspended solids in the reactor at each injection). Comparison with the UASB without chitosan addition, the UASB had a 24 to 37% larger particle size and a 6 to 41% longer solids retention time. In addition, the reactor performances were also enhanced. The UASB with chitosan addition had a 9 to 59% lower effluent chemical oxygen demand (COD), 4 to 10% higher COD removal, up to 35% higher biogas production rate, and a 16 to 68% lower biomass washout. The paired t-test analysis indicated that these performance parameters were significantly different (P < 0.05).
Lertsittichai
Sittpong
S
Department of Chemical Engineering, King Mongkut's Institute of Technology, North Bangkok, Thailand.
Lertsutthiwong
Pranee
P
Phalakornkule
Chantaraporn
C
D018533:Biomass; D019149:Bioreactors; D002614:Chelating Agents / Q000737:chemistry; D048271:Chitosan / Q000737:chemistry*; D005232:Fatty Acids, Volatile / Q000378:metabolism; D005427:Flocculation; D018857:Food Packaging; D005638:Fruit; D007220:Industrial Waste; D010316:Particle Size; D012722:Sewage; D014865:Waste Disposal, Fluid / Q000379:methods*
D002614:Chelating Agents; D005232:Fatty Acids, Volatile; D007220:Industrial Waste; D012722:Sewage; D048271:Chitosan