Experimental Study On Treatment Of Penicillin Wastewater By Modified Zeolite Combined With Activated Sludge

China is one of the largest producers and consumers of antibiotics worldwide.Excessive antibiotics and unreasonable use lead to excessive residues entering the environment,posing a great threat to human health and environmental safety.Traditional activated sludge processes cannot efficiently treat such wastewater.Therefore,from the economic and practical point of view,this experiment adds different modified zeolite to the reactor based on the SBR process to provide a carrier for the microorganism and strengthen the biological activity in the reactor to improve the treatment efficiency of penicillin wastewater.The main work done is as follows:?1?In this research,several conventional methods have been used to modify natural zeolite,including modification with different concentrations of hydrochloric acid?HCl?solution,different concentrations of sodium hydroxide?NaOH?solution,different temperature burning modification and Cetyltrimethylammonium bromide?CTAB?modification under different conditions.The adsorption test of penicillin was carried out with zeolite before and after modification.The results show that natural zeolite does not have adsorption to penicillin,while other modified zeolites exhibit different adsorption properties for penicillin.At the same time,the modified zeolite with hydrochloric acid concentration of 3mol/L,sodium hydroxide concentration of 3mol/L,temperature of 600°C and surfactant concentration of 20mmol/L,reaction temperature of 30°C and modification time of 6h,The adsorption of penicillin was the best,and the adsorption efficiencies were 11.79%,14.77%,8.78%and 39.52%,respectively.?2?The natural zeolite and different modified zeolites were characterized by scanning electron microscopy,X-ray diffraction,infrared spectroscopy and thermogravimetric analysis.Scanning electron micrographs show that the modified zeolite is significantly different in morphology from natural zeolite.The XRD pattern showed that the peak shape of the zeolite modified by acid,alkali and high temperature changed,and the spectrum of the organic modified zeolite was not much different from that of natural zeolite.The IR characterization results showed that the acid and alkali modified zeolite exhibited bending vibration and stretching vibration of the bond and displacement of the peak.The high temperature modified zeolite showed that the absorption band of the bound water almost disappeared.The CTAB modified zeolite showed a distinct CH₂-longitudinal vibrational peak between 2900-2850cm^-1,indicating that the surfactant has been successfully loaded onto the zeolite surface.The rmogravimetric analysis of natural and several modified zeolites showed that except for the high temperature modified zeolite at 600°C,there was no significant mass loss,and the remaining zeolites showed mass loss.The thermal weight loss conditions of natural zeolite,HCl modified zeolite,NaOH modified zeolite,CTAB modified zeolite and high temperature modified zeolite were 6.93%,7.81%,11.10%,6.50%and 0.7%,respectively.?3?The activated sludge was domesticated by artificially prepared wastewater containing penicillin using the SBR process.The effects of nutrient elements,dissolved oxygen,pH and temperature on activated sludge were investigated.The results showed that when the dissolved oxygen was 3mg/L-4mg/L,the temperature was at room temperature?22°C-28°C?and the pH was 6.5,the COD removal rate in the simulated wastewater was stable at about 80%,and the SVI value was stable at around 130.?4?The different modified zeolites were combined with activated sludge to treat penicillin wastewater.The results showed that the combined treatment of CTAB modified zeolite and activated sludge had the best effect,and the COD removal rate reached about 83%.Subsequently,the dosage of CTAB-modified zeolite was changed and the simulated wastewater was continuously treated with activated sludge to investigate the degradation of COD,ammonia nitrogen and total phosphorus at different dosages.The results showed that when the dosage of zeolite was 5g/L,the treatment efficiency of each index was the best.The degradation rate of COD reached 85.16%,the removal rate of ammonia nitrogen was 86.24%,and the total phosphorus reached 88.23%.In this paper,the natural adsorption material zeolite is combined with the SBR process to treat penicillin wastewater.It can not only degrade penicillin efficiently but also minimize ecological safety problems,which provides a basis for the treatment of penicillin in the environment.