A Pilot-scale Study On Microelectrolysis-UASB-PSB Process For Pharmaceutical Wastewater Treatment

With the development of the pharmaceutical industry in our country, muchattention has been paid to the pollution of the wastewater treatment and the relevantsolutions. As for most pharmaceutical enterprises, high concentration pharmaceuticalwastewater is one kind of refractory industry wastewater due to the complicatedcomponents, high quantity organic compounds, deep color and low biodegrade ability.Furthermore, it is difficult to biodegrade the antibiotic wastewater and singlewastewater treatment has been imperfect. Hence, it is imperative to develop a serieseffective new process for wastewater treatment, which can meet the increasing strictdischarge standards.On the basis of the relate studies both at home and abroad, taking the waste waterfrom a pharmaceutical factory in Shandong which features high COD concentrationranging from 10000 to 15000mg/L as well as salty concentration about 4 percent asthe disposal object and the writer made a research on the application of the method, todispose it, the method of unitized iron-carbon micro electrolysis-UASB and thetechnique of using photosynthetic bacteria(PSB). According to the research on itscharacteristics, pretreatment is required specifically for its low biodegradability.Iron-carbon micro electrolysis proves its effectiveness after the comparison amongkinds of pretreatment methods. Results showed iron-carbon micro electrolysis canremove35% of COD while improve B/C to 0.2,far better than any other pretreatmentmethod in terms of the biodegradability improvement, which helps to benefit thelatter bio-process. Factors affecting the efficiency by iron-carbon micro electrolysisranked influent pH >effluent pH >HRT. The optimal condition concluded that influentpH=2.0, HRT=120min, effluent pH=9. Upon analysis,the mechanism of iron-carbonmicro electrolysis based on an integrated process including galvanic reaction,oxidation-reduction reactions, electrochemical adsorption physical adsorption andcoagulation.After the pretreatment, UASB is applied for further treatment, which initiateswith high concentration influent and low removal ratio. It took about 60 days for thedomestication of granular sludge from municipal sewage treatment system, which is faster than common anaerobe reactors. Results showed the optimal conditions ofUASB system summarized HRT=40h, temperature=35～37oC, pH=7.8～8.2 and over82% of COD removal.Another research has been studied the technological condition of disposingpharmaceutical waste water by photosynthetic bacteria in the experiment. The resultshows that PSB method has its unusual superiority to dispose the waste water withhigh organic load from pharmaceuticals industry. The higher the organic load is, themore efficient the method is. When COD of the waste water is about1000~3000 mg/L,the HRT=4 days, the PSB reaction system has the optimum processing effect, theeffluent COD is 200~500mg/L and the degerate of COD is over 80%.