TY - JOUR
T1 - Investigation on laboratory and pilot-scale airlift sulfide oxidation reactor under varying sulfide loading rate
AU - Pokasoowan, Chanya
AU - Kanitchaidecha, Wilawan
AU - K. C., Bal Krishna
AU - Annachhatre, Ajit P.
PY - 2009
Y1 - 2009
N2 - Airlift bioreactor was established for recovering sulfur from synthetic sulfide wastewater under controlled dissolved oxygen condition. The maximum recovered sulfur was 14.49 g/day when sulfide loading rate, dissolved oxygen (DO) and pH values were 2.97 kgHS-/m3-day, 0.2-1.0 mg/L and 7.2-7.8, respectively. On the other hand, the increase in recovered sulfur reduced the contact surface of sulfide oxidizing bacteria which affects the recovery process. This effect caused to reduce the conversion of sulfide to sulfur. More recovered sulfur was produced at high sulfide loading rate due to the change of metabolic pathway of sulfide-oxidizing bacteria which prevented the toxicity of sulfide in the culture. The maximum activity in this system was recorded to be about 3.28 kgS/kgVSS-day. The recovered sulfur contained organic compounds which were confirmed by the results from XRD and CHN analyzer. Afterwards, by annealing the recovered sulfur at 120°C for 24 hrs under ambient Argon, the percentage of carbon reduced from 4.44% to 0.30%. Furthermore, the percentage of nitrogen and hydrogen decreased from 0.79% and 0.48% to 0.00% and 0.14%, respectively. This result showed the success in increasing the purity of recovered sulfur by using the annealing technique. The pilot-scale biological sulfide oxidation process was carried out using real wastewater from Thai Rayon Industry in Thailand. The airlift reactor successfully removed sulfide more than 90% of the influent sulfide at DO concentration of less than 0.1 mg/L, whereas the elementary sulfur production was 2.37 kgS/m3-day at sulfide loading rate of 2.14 kgHS-/m3-day. The sulfur production was still increasing as the reactor had not yet reached its maximum sulfide loading rate.
AB - Airlift bioreactor was established for recovering sulfur from synthetic sulfide wastewater under controlled dissolved oxygen condition. The maximum recovered sulfur was 14.49 g/day when sulfide loading rate, dissolved oxygen (DO) and pH values were 2.97 kgHS-/m3-day, 0.2-1.0 mg/L and 7.2-7.8, respectively. On the other hand, the increase in recovered sulfur reduced the contact surface of sulfide oxidizing bacteria which affects the recovery process. This effect caused to reduce the conversion of sulfide to sulfur. More recovered sulfur was produced at high sulfide loading rate due to the change of metabolic pathway of sulfide-oxidizing bacteria which prevented the toxicity of sulfide in the culture. The maximum activity in this system was recorded to be about 3.28 kgS/kgVSS-day. The recovered sulfur contained organic compounds which were confirmed by the results from XRD and CHN analyzer. Afterwards, by annealing the recovered sulfur at 120°C for 24 hrs under ambient Argon, the percentage of carbon reduced from 4.44% to 0.30%. Furthermore, the percentage of nitrogen and hydrogen decreased from 0.79% and 0.48% to 0.00% and 0.14%, respectively. This result showed the success in increasing the purity of recovered sulfur by using the annealing technique. The pilot-scale biological sulfide oxidation process was carried out using real wastewater from Thai Rayon Industry in Thailand. The airlift reactor successfully removed sulfide more than 90% of the influent sulfide at DO concentration of less than 0.1 mg/L, whereas the elementary sulfur production was 2.37 kgS/m3-day at sulfide loading rate of 2.14 kgHS-/m3-day. The sulfur production was still increasing as the reactor had not yet reached its maximum sulfide loading rate.
KW - Thailand
KW - airlift reactors
KW - bioreactors
KW - oxidation
KW - sulfides
UR - http://handle.uws.edu.au:8081/1959.7/uws:32120
U2 - 10.1080/10934520802515426
DO - 10.1080/10934520802515426
M3 - Article
SN - 1093-4529
VL - 44
SP - 87
EP - 98
JO - Journal of Environmental Science and Health. Part A: Toxic Hazardous Substances and Environmental Engineering
JF - Journal of Environmental Science and Health. Part A: Toxic Hazardous Substances and Environmental Engineering
IS - 1
ER -