TITLE:
Effects of Mixing HTS and FCC Wastwaters on the Quality of A/O Effluent
AUTHORS:
Ibrah Landi Ali, Oumarou Tidjani Malam Mani, Moumouni Wagé Abdoul Razak, Jun Lu
KEYWORDS:
Ammonia-N, Anoxic/Oxic A/O System, Hollow Titanium Silicate, Fluid Catalytic Cracking, Total Nitrogen
JOURNAL NAME:
Journal of Environmental Protection,
Vol.16 No.12,
December
29,
2025
ABSTRACT: The effects of mixing of two kinds of wastewaters Hollow Titanium Silicate (HTS) zeolite and Fluid Catalytic Cracking (FCC containing QACs) through various tests in the percentage ratios of 0.50%, 0.65%%, 0.70%, 0.80%, 0.9%, 1.0%, 1.1% and 1.2% to reduce nitrogen species and COD by using A/O system are studied. The domestication has carried out under the following conditions: pool A’s DO maintained at 0.5 mg/L while pool O’s DO controlled within 2 - 4 mg/L at room temperature. The C/N ratio was regulated to 4.0:1.0 by glucose addition and the hydraulic residence time (HRT) was 70 h. Pool O’s pH was controlled at 7.5 - 8.5 by adding NaOH, the wastewater’s reflux ratio was controlled to R = 500%, and the sludge reflux ratio was r = 100%. During the experiment, the inlet and outlet water’s both COD, ammonia-N and TN as well as SV30, MLSS and SVI were tested and analyzed. The results showed that during process with amounts of mixed HTS wastewater to FCC wastewater of 0.80%, 0.90%, 1.0%, 1.1% to 1.2%, ammonia-N removal was effective. The COD concentration was also reduced to less than 60 mg/L. However, TN elimination did not attain discharge standard. Thereafter, by adjusting the C/N ratio at 5.5:1.0 under temperature at 25˚C, the ammonia-N concentration was 3 - 4 mg/L, the TN concentration was reduced to 37 mg/L and COD concentration was 58 mg/L. With the inlet water COD concentration of 1815 mg/L (including the COD concentration of glucose), and ammonia-N concentration of 330 mg/L, HTS wastewater mixed with FCC at ratio of 1.0%, C/N ratio of 5.5:1.0, temperature between 25˚C - 37˚C, the effluent’s ammonia-N concentration remained to 3 mg/L, TN concentration lower than 40 mg/L and COD concentration less than 60 mg/L showing thus the process achieved the nitrogen species removal standard. However, when the temperature of A/O system wastewater was increased to 40˚C or became lower than 25˚C, the sludge was lost and the whole system was destroyed.