| Activated sludge method is the mainstream of sewage treatment process,the removal of organic matter in water mainly depends on the adsorption and degradation of activatedsludge,therefore,it is of great theoretical significance to study the adsorption and degradationcharacteristics of activated sludge to organic matter.In this paper,the activity of sludge was inhibited by nitrogen blowing,the adsorption degradation and simple adsorption characteristics of activated sludge were studied,the effects of sludge concentration,pH value and temperature on the adsorption degradation were also investigated,and the adsorption degradation of sludge to organic matter from different carbon sources were studied.The experimental resultsas follows:(1)The removal of organic matter in sewage by activated sludge was mainly composed of adsorption and degradation processes,the adsorption process is mainly composed of rapid adsorption,the COD concentration of the wastewater was almost unchanged after 2h reaction,the removal rate of COD by activated sludge was 50.5%;When the adsorption is simple,the COD removal rate is 46.1%,the removal rate of COD by activated sludge of degradation was 4.4%.(2)With the increase of sludge concentration,the adsorption capacity of activated sludge to adsorb organic matter in water increased,and the removal rate of COD increased,the adsorption rate was the best when the sludge concentration was 4000mg/L,the COD removal rates were 65.6%,andthe COD removal rate did not change when the sludge concentration continued to increase;the higher the sludge concentration,the greater the amount of sludge adsorption alone,the sludge concentration of 4000 mg / L,COD removal rate of 54.7%.(3)With the increase of pH value,the adsorption and desorption amount of activated sludge to organic matter in water increased,and the removal rate of COD increased.When the pH=8,the removal rate of COD reached the highest,sewage COD removal rate of 45.9%,andthe COD removal rate did not change when the pH continued to increase;when the pH increased,the adsorption capacity of sludge increased,when pH = 8,COD removal rate was 44.2%.(4)With the increase of temperature,the amount of activated sludge on the adsorption of organic matter increased,COD removal rate increased,When the temperature is 30 ?,the removal rate of COD reached the highest,sewage COD removal rate of 51.1%,andthe COD removal rate did not change when the temperature continued to increase;when the temperature increased,the adsorption capacity of sludge increased,when the temperature is 30 ?,COD removal rate was 48.4%.(5)Activated sludge adsorption and degradation of organic matter in accordance with pseudo-first-order kinetics model,the first-order equation is y =-0.3525 x + 5.7656,the correlation coefficient R2 = 0.9905,the equilibrium adsorption capacity qecal value was 319 mg / L,and the experimental adsorption capacityqeexp= 291 mg / L.(6)The pseudo-first-order kinetics equation of organic matter adsorbed in activated sludge was y=-0.4574 x + 5.5651,the correlation coefficient R2 = 0.9963,the equilibrium adsorption capacity qecal value was 261 mg / L,and the experimental adsorption capacity qeexp= 238 mg / L,the process of adsorbing organic matter in activated sludge alone is in accordance with the pseudo-first-order kinetics model.(7)The adsorption and degradation process of activated sludge to organic matter accorded with Langmuir isothermal adsorption model,the correlation coefficients R2 is 0.97.At 15,25,35 ?,the maximum adsorption capacity qm were 277.78,344.83,416.67 mg / L;the simple adsorption process of activated sludge to organic matter is in accordance with Freundlich isothermal model,the correlation coefficients R2 is 0.99.(8)According to the fluorescence scanning spectrum,it can be seen that the activated sludge can effectively remove the Protein-like substance,Fulvic acid and Humic acid.The reductions of the fluorescence peaks of the three organic compounds after the adsorption and degradationof the activated sludge were 25.9%,9.8% and 74.3%,the reductions of the fluorescence peaks of the three organic compounds after the simpleadsorption were 22.1%,9.4% and 41.2%. |
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