Study On Wastewater Treatment Of Polytetrahydrofuran Production

This subject conducted research for processing poly tetramethylene ether glycol?PTMEG?wastewater.An effective production process was designed and verified by experiments.The wastewater of the methanol and hydrogen plant area mainly contained a small amount of phosphate,the lower alcohols and BYD,basically there were no toxic and biodegradable materia,Water quality ingredients was relatively simple.There are more complex ingredients such as tar,carbon black,heterocyclic and the NMP refractory substances in natural gas to acetylene wastewater,but the concentration is not high.The high concentration of organic wastewater was produced by BDO and PTMEG production unit containing THF,PTMEG and other small amounts of toxic and biodegradable material,however,the biodegradability of wastewater was better.The two wastewater treatment processes were designed for the wastewater characteristics in the topic.The simulation experiment was tested and verified.The process composed of adjusting tank,anaerobic tank,aerobic tank,MBBR and two settling tank.The experimental wastewater was artificial prepared except for formaldehyde wastewater that was conducted by a chemical plant wastewater.The trial of the full capacity of each reactor and the impact test were conducted.The experiment showed that the effluent effect was the best when COD was in the range of 1000mg/L-1500mg/L in aerobic reactor site wastewater contrast pilot phase.The highest influent COD concentration was 2227 mg/L,the average influent COD concentration was 968 mg/L,and the COD removal efficiency was 91%.After running a test of the impact load stage,the aerobic reactor can stand up the impact of 40 ppm formaldehyde.However,the phenomenon of sludge bulking was found,which was caused by unbalanced nutrients and low substrate concentration within the aeration.The Flotation equipment was running well,less dosage of PTMEG,oils,and the insoluble material has good removal efficiency.The average removal of Cu²⁺ was up to 83%by the device which can reduce effect of Cu²⁺ to microorganisms.The influent COD of Ozone-activated carbon system is 308 mg/L,the effluent COD can reduce to 88 mg/L.however,the removing of formaldehyde is effectively.The operation of the site and water quality analysis of PTMEG project wastewater biochemical properties,which contain THF,NMP and some alcohols are readily biodegradable.Fenton reagent oxidation of easily oxidized material,resulting in a large pharmaceutical consumption.Cancel the process was proved by Experimental.The second process was mainly combined by PTMEG treatment which depends on Biological.The result is that when it runs continuously,the concentration of NM and THF was 100ppm in inlet water,the flow is 1m3/h,if the concentration of PTMEG in inlet water under 150 mg/L,the system will not be affected by the concentration of the drug,and the CODCr in out water meets the national standard.Other wise,the treatment efficiency is not ideal.After added a flotation unit between the service reservoir and the regulating reservoir,the treatment efficiency reached to the expectation perfectly which suggest that this technique is feasible.