A Study Of Sodium Chloride Impact On The COD Removal Efficiency In The Advaced Anaerobic Treatment Process Of The High Concentration Organic Wastewater

With increasingly strict standard of Industrial effluents, it is very urgent to study on the treatment technic of hyphaline industrial wastewater. Saline wastewater contains wastewater discharged from direct using and some Industrial effluents, such as chemical industrial wastewater, food wastewater and pharmaceutical wastewater, etc. Because of the high salt content, the salinity wastewater is not easy to be treated with anaerobic biological technology now. In this dissertation, a laboratory study of the feasibility and degradation mechanism of the advanced anaerobic treatment to saline organic wastewater, which is in the methanation stage was conducted. Moreover, an experiment about highly Cl- concentration of pharmaceutical wastewater treatment to study the feasibility of anaerobic treatment to practical saline organic wastewater with UASB was carried out. Main work targets and conclusions are as follows:(1) In the sludge culture experiment, sludge tolerating high Cl- industrial wastewater was acclimated by increasing the volumetric loading rate and Cl- concentration gradually. 83% of COD was removed and the effluence VFA was 1.5~3.0 mmol/L, when the concentration of Cl- in the influent was 8000 mg/L, the volumetric loading of the system was 4.5~5.0kgCOD/ (m3·d), and the effluence VFA was 1.5~3.0 mmol/L.The acclimated sludge adapted to the change of the concentration of Cl-.(2) By using artificial beer wastewater (50mgCL-/L), the Cl- concentration inhibition to anaerobic sludge cultivated by no Cl- was increased gradually with influent Cl- concentration added from 50 to 9050mg/L, when the volumetric loading was 4.0 to 5.0 kgCOD/ (m3·d), the influent runoff was 3L/d. Methanogenic bacterium was more sensible, the Cl- concentration inhibition to the batertium was heavier, biogas production was reduced and theVFA was ineasing. And the COD removal efficiency was reduced. Sludge cultivated by Cl- concentration was less inhibited and the methanogenisis activity in this sludge was able to recover faster than the other.(3) The anaerobic sludge in the UASB reactor had been cultivated for 70 days at mesophilic condition (37±2)℃, then it was used to treat pharmaceutical wastewater. The results showed that when the influent Cl- was 4800 to 5000mg/L, the volumetric loading was 4.5~5.0kgCOD/ (m3·d) and the pH was 6.8 to 7.2, the COD removal efficiency of the reactor could reach to 80%. The efflunce VFA was 1~3mmol/L, the biogas production was 7.5L/d. And the acclimated miobes showed high resistance to Cl- inhibition. The operation results indicated that the technology of acclimating anaerobic granular sludge to treat the highly Cl- wastewater has broadened the scope of the application of anaerobic treatment, and provided more technology choices for the industry wastewater treatment.