Study And Application Of The Treatment Of Pharmaceutical Waste Water With High Concentration Of Nitrogen And Phosphorus By Combination Process Of MAP+ABR+A~2/O

A pharmaceutical technology company specialized in chemical synthesis drugproduction like adenine, E-2, BL,etc. A certain amount of wastewater with highconcentrations of Chemical Oxygen Demand, nitrogen and phosphorus discharged inthe process of production, used the combination process of MAP+ABR+A2/O to toprocess the wastewater, controled the process operating conditions, MAP sectionremove the majority of nitrogen and phosphorus, and recycling the production:magnesium ammonium phosphate precipitation, ABR section remove most organicmatter by high organic load and anaerobic granular sludge, A2/O section remove theresidual nitrogen, phosphorus and organic pollutants, and decomposition of organicnitrogen and organic phosphorus in ABR section, the effluent’s indexes couldcompletely meet the discharge standard of water pollutants for pharmaceuticalindustry chemical synthesis products category(GB21904-2008)。This paper analyzed the optimal operating conditions of MAP process forphysical and chemical method nitrogen and phosphorus removal, the acclimationculture conditions of anaerobic granular sludge in ABR process, and the optimaloperating conditions of A2/O process for biological method nitrogen and phosphorusremoval. The start and of ABR process and A2/O process were also studied.1) The ammonia nitrogen concentration of experimental wastewater is1544mg/Land the phosphorus concentration is3419mg/L. Ammonia nitrogen and phosphoruscan be removed from the wastewater by forming magnesium-ammonium-phosphate (MAP) precipitate with magnesium salt. The optimal experimentalconditions: pH=9.5, Mg: N=1.2:1, N: P=1, temperature20℃, time1h, selectedMgCl2·6H2O as magnesium salt. Experimental residual concentrations of ammonianitrogen, phosphorus were48.7mg/L,14.6mg/L, the ammonia nitrogen andphosphorus removal rates were96.7%,99.6%.2) The CODCrconcentration of enterprise drainage is between4000~8000mg/L, with an average of5000mg/L, the ammonia nitrogen concentration is between2000~4000mg/L, with an average of2500mg/L, the phosphorus concentration is between4000~8000mg/L, with an average of5500mg/L, treating byMAP+ABR+A2/O combined process, the average concentration of effluent CODCris70mg/L, the total CODCrremoval rate was98%, the average concentration ofeffluent ammonia nitrogen is15mg/L, the total ammonia nitrogen removal rate was99.4%, the average concentration of effluent phosphorus is15mg/L, the totalphosphorus removal rate was99.9%. All the effluent’s indexes could completely meetthe discharge standard of water pollutants for pharmaceutical industry chemicalsynthesis products category(GB21904-2008)。3) The high ammonia nitrogen mixed with the high phosphorus wastewater, thetotal content of wastewater is150m3/d, NH3–N of the influent was at an average of2500mg/L, TP of the influent was at an average of5500mg/L, the molar ratio of N/Pis0.95to0.98. Controlled operating conditions: pH9.0~9.5, the dosage ofMgCl2·6H2O was6t/d. The fist MAP response, NH3–N of the effluent was200~500mg/L and the removal rate of NH3-N was about85%; TP of the effluent was100~250mg/L and the removal rate of TP was about95%. The second MAP response, NH3–Nof the effluent was50~100mg/L and the removal rate of NH3-N was about80%; TPof the effluent was10~30mg/L and the removal rate of TP was about90%.4) ABR started with a mode of intermittent water with low load. At thebeginning of the startup the volume loading was controlled to0.5kg CODCr/(m3.d),then increased the concentration and volume of the influent until it met the designvolume loading3.0kg CODCr/(m3.d) and the pH of the system was controlled from6.8to7.5with a90days startup time. The CODCraverage concentration of theinfluent was5000mg/L and the effluent was900~1100mg/L when the removal rateof CODCrwas about80%after the stable running of ABR which had a goodanti-impact ability to the CODCr.The ammonia nitrogen concentration of the influentwas50~150mg/L and the effluent ammonia nitrogen concentration was100~300mg/L which maintained the higher organic nitrogen content in the wastewater.5) A2/O started with a mode of intermittent water with low load. SV increased to30%and the MLSS was3000~4000mg/L during the startup time. The start runningconditions were controlled that pH of the anaerobic and anoxic area was7.0~7.5andthe aerobic area was7.0~8.0; DO of the anaerobic, anoxic and aerobic area were 0~0.2mg/L,0~0.5mg/L and1~4mg/L; the return mixed liquid ratio was200%; thesludge reflux ratio was70%. After the stable operation, CODCrof the influent was900~1100mg/L at an average of1000mg/L and the effluent was below100mg/Lwhen the removal rate is more than90%; NH3–N of the influent was200-400mg/L atan average of300mg/L and the effluent was5~20mg/L when the removal rate ofNH3-N was about95%; TP of the influent was20~30mg/L at an average of25mg/Land the effluent was0.6mg/L when the average removal rate was97%.