Experimental Study On Treatment Of Polluted Water By A Biological Contact Oxidation Process Filled With Bamboo Filler

With the development of cities, lakes and rivers have suffered serious pollution. Theproblem of increasing eutrophic water bodies is making researchers to develop economicaland effective technologies much further for water body remediation. Biological contactoxidation process is a typical immersed biofilm system, which has the advantage ofresistance to load shock, lower utility consumption, simple operation and better treatingeffectiveness. Bio-film carrier is the key component of the biological contact oxidationand the filler’s performance directly influences the treating effectiveness. In this paper, abiofilm carrier made of bamboo was developed, which was source widely, crafting cheap,free of pollution. Laboratory-scale reactors filled with bamboo carriers were used to treatthe badly contaminated Huxi River. The main contents and conclusions are as followings:(1) Through the determination of5indicators such as total oxygen transfer coefficient(KLa), oxygen transfer rate (dC/dT), aerobic capacity (R0), oxygen utilization (EA) andoxygenated dynamic efficiency (EP) to investigate the influence on the reactor’soxygenated ability by3different fillers such as the elastic plastic filler, bamboo filamentfiller and hollow–sphere bamboo filler, which using intermittent unsteady aeration methodfor water oxygenated performance experiment in the same conditions.(2) A biological contact oxidation process filled with either bamboo filament fiber orhollow-sphere bamboo filler was studied to treat the water from Huxi River. The treatmenteffect was ccompared with that of the traditional elastic plastic filler. The filler’smembrane-forming time, biomass and effect of wastewater treatment were investigated.The results indicated that the hollow-sphere bamboo filler was easily to bemembrane-formed, which consumed the least time and gained the most biomass. Besides,the bamboo filler had the superiority over the traditional elastic plastic filler inmembrane-forming and wastewater treatment for its large effective specific surface area.(3) The optimal operating conditions were also determined, the HRT and DO for thecontinuous aeration were7.5h and3mg/L, respectively, and the alternate operation ofanaerobic and aeration for the intermittent aeration were1.2h and6.3h, respectively. The experimental results indicated that the hollow-sphere bamboo filler had the besteffectiveness of wastewater treatment among the three tested fillers. For the reactorpacked with hollow-sphere bamboo filler, the average removal of CODCr, TN, NH3-N andTP were66.7%,47.9%,57.1%,30.6%, and the average effluent concentration of CODCr,TN, NH3-N and TP were15.6mg/L,8.5mg/L,6.8mg/L,1.2mg/L, respectively, underoptimal conditions for continuous aeration. While under optimal conditions forintermittent aeration, the average removal of CODCr, TN, NH3-N and TP were64.08%,39.95%,60.7%,54.68%, and the average effluent concentration of CODCr, TN, NH3-Nand TP were14.5mg/L,9.2mg/L,5.5mg/L,0.5mg/L, respectively. However, only theaverage effluent concentration of CODCrcould reach class Ⅲ of the Environmentalquality standards for surface water.The experimental results showed that the hollow-sphere bamboo filler had the besteffects of the wastewater treatment among the three tested fillers. These experimentalresults also indicated that the bamboo filler might replace elastic plastic filler in thebiological contact oxidation process for its advantage over elastic plastic filler in thereactor oxygenated performance, membrane-forming time, biomass and effect ofwastewater treatment. Furthermore, the advanced treatment is necessary for water bodyremediation to reach class Ⅲ of the Environmental quality standards for surface water,while the biological contact oxidation process filled with bamboo filler could only serve asa pre-treatment technology.