Effect Of Metal Ions On The High Organic Loading Anaerobic Digestion Of Penicillin Slag

With the development of pharmaceutical industry in China,it has become the world's largest producer and exporter of antibiotics country.The amount of antibiotic slag can not be ignored.There is a potential risk to the environment because of the residues in the slag.Antibiotic residue was written in the"National List of Hazardous Wastes"in 2008.The safe and reasonable disposal of antibiotic slag has become the bottleneck of the current pharmaceutical industry development.Improper handling,will result in a great waste of resources and endanger the environment.Ultimately,it will harm the health of mankind.Anaerobic fermentation technology is an effective way for organic waste to be harmless and resourceized.In this paper,three kinds of metal ions such as iron,cobalt and nickel were added by pretreatment,and the changes of the physical and chemical indexes were analyzed.The effects of metal ions on penicillin slag is subjected to high-load anaerobic fermentation to strengthen the regulation.It can avoid the problem of acidification,ammonia nitrogen inhibition and low volume gas production rate during the high load operation.Providing technical support for engineering application.The main work is as follows:1.The physical and chemical properties and potentials of penicillin slag gas production were studied.The results of batch fermentation showed that under different temperature conditions,the anaerobic digestion performance of different loaded penicillin slag fermentation broth was different.When the TS>2.5%,due to the high load,making the fermentation failed to start successfully.When TS was 0.5%,1.0%,1.5%,2.0%,the gas production rate of load was 657.1 mL/gTS,582.2 mL/gTS,457.9 mL/gTS,353.6 mL/gTS,282.9 mL/gTS,respectively.2.Pretreatment mainly includes alkali heat,microwave and ultrasonic.The alkali heat optimum conditions were as follows:temperature 60?,time 1.25 h,alkalinity 6%.SCOD increased by 125%compared with the control.Microwave pretreatment optimum conditions:microwave power 240 W,time 240 S,SCOD control was improved by 69.6%.Ultrasound's optimum condition:ultrasound 3 S,gap 5 S,ultrasound 15 times,SCOD increased by 62%compared with the control.3.The effect of metal ion on anaerobic digestion of penicillin slag was determined by batch anaerobic fermentation.In the anaerobic fermentation of slag,the maximum treatment load is 2.5%.After adding metal ions,the organic loading and the gas production efficiency are significantly improved.The effects of different metal ions on the anaerobic digestion were determined by climbing experiment and response surface analysis.The addition of different metal ions was Fe²⁺500 mg/L,Co²⁺30 mg/L,Ni²⁺0.3 mg/L,and the biogas production was higher than that of the control group increased by 63.8%,VS removal rate increased by 83.6%compared with the control group.4.Through the semi-continuous anaerobic fermentation process,it is determined that the addition of three kinds of metal ions,iron,cobalt and nickel can significantly improve the organic load of the fermentation system.The mechanical load increased from 2.5gTS/L/d TS to 5.0 gTS/L/d,the volume gas production rate was 1.24 L/L/d,and the gas production rate of load was 1.26 L/gTS,the pH value of the fermentation system is 7.2-7.5,volatile acid is 2000 mg/L about,ammonia nitrogen content remained at 2000 mg/L or so.While improving the organic load at the same time,significantly improve system stability.