响应面法优化负压原位碱度蒸汽汽提脱氨处理兰炭废水的研究OA北大核心CSTPCD

A negative pressure in-situ alkalinity steam-stripping technique was employed to extract ammonia from semi-coke wastewater.The influence of three single factors,steam a-mount,inflow velocity and pH on the ammonia nitrogen removal efficacy was examined.The in-teraction effects among these factors were studied and analyzed in detail using a response surface model.The experimental results indicate that all three factors significantly affect the ammonia nitrogen removal ratio within the response range.According to the response surface results,the contribution of the three factors to the ammonia nitrogen removal ratio ranks as follows:steam a-mount,inflow velocity,and pH.The significance of the interaction effects decreases in the order of steam amount and inflow velocity,steam amount and pH,and inflow velocity and pH.The optimal conditions for ammonia nitrogen removal,determined using the response surface meth-od,are a steam amount of 0.75 kg/h,an inflow velocity of 2.43 L/h,and pH of 8.96,under which the predicted ammonia nitrogen removal ratio can reach to 96.53%.Verification through repeated experiments show that the experimental removal ratio under these conditions is 95.7%,indicating good agreement between the experimental values and the predicted values from the re-sponse surface method.The coefficient of determination indicates that the model can explain 95%of the variation in the response values,with no lack-of-fit factors.Additionally,the negative pressure in-situ alkalinity steam-stripping process also shows some effectiveness in removing vol-atile phenols and COD.