The treatment plant at this industrial facility treats approximately 0.3 mgd waste containing phenolic compounds. Over the past year the treatment works has improved performance and consistently been able to produce good quality effluent with respect to phenol, however, an improvement in performance was required to meet future discharge limits.
To achieve this level of treatment, the industry operates an activated sludge plant with two aeration basins in series and two secondary clarifiers in series. The activated sludge system comprises an above ground concrete tank with fixed high speed aerators operated with a high solids level to achieve single stage nitrification and twin secondary clarifiers with scraper mechanisms.
The degradation of phenol can be measured by a reaction coefficent K calculated as follows:
(Li - Lo) / ( Lo x * t)
Li = Influent phenol conc.
Lo = Effluent phenol conc.
t = retention time in the aeration basin
In mixed units the average K value is shown in the graph to the right. After a lag time of four weeks the phenol degradation rate was significantly improved by the addition of Bio-Systems to the treatment plant. The lag time of four weeks indicates that there was phenol build up in the mixed liquor which was being degraded by the Bio-Systems product. Once this residual had been degraded the improved K factor showed as an improvement in the final effluent phenol concentration.
The above data is the K value for phenol at the end of the trial. The addition of Bio-Systems was resumed at a high dose level for the 26th thru 28th of Oct. Almost immediately, the phenol degradation rate increased approximately 50% then returned to the lower level when the addition was stopped.
The above data is very consistent with our experience at other facilities treating similar wastewaters and confirms that the Bio-Systems product is capable of significantly increasing the biodegradation of phenol.