Abstract: Production of biogas from bakery waste was enhanced
by additional bacterial cell. This study was divided into 2 steps. First
step, grease waste from bakery industry-s grease trap was initially
degraded by Pseudomonas aeruginosa. The concentration of byproduct,
especially glycerol, was determined and found that glycerol
concentration increased from 12.83% to 48.10%. Secondary step, 3
biodigesters were set up in 3 different substrates: non-degraded waste
as substrate in first biodigester, degraded waste as substrate in
secondary biodigester, and degraded waste mixed with swine manure
in ratio 1:1 as substrate in third biodigester. The highest
concentration of biogas was found in third biodigester that was
44.33% of methane and 63.71% of carbon dioxide. The lower
concentration at 24.90% of methane and 18.98% of carbon dioxide
was exhibited in secondary biodigester whereas the lowest was found
in non-degraded waste biodigester. It was demonstrated that the
biogas production was greatly increased with the initial grease waste
degradation by Pseudomonas aeruginosa.
Abstract: The objectives were to identify cyanide-degrading
bacteria and study cyanide removal efficiency. Agrobacterium
tumefaciens SUTS 1 was isolated. This is a new strain of
microorganisms for cyanide degradation. The maximum growth rate
of SUTS 1 obtained 4.7 × 108 CFU/ml within 4 days. The cyanide
removal efficiency was studied at 25, 50, and 150 mg/L cyanide. The
residual cyanide, ammonia, nitrate, nitrite, pH, and cell counts were
analyzed. At 25 and 50 mg/L cyanide, SUTS 1 obtained similar
removal efficiency approximately 87.50%. At 150 mg/L cyanide,
SUTS 1 enhanced the cyanide removal efficiency up to 97.90%. Cell
counts of SUTS 1 increased when the cyanide concentration was set
at lower. The ammonia increased when the removal efficiency
increased. The nitrate increased when the ammonia decreased but the
nitrite did not detect in all experiments. pH values also increased
when the cyanide concentrations were set at higher.