Experimental Study On The Degradation Of Dimethyl Phthalate In Upflow Anaerobic Sludge Blanket Reactors

The phthalates in low concentration can disrupt people and animals'endocrine system. As a plasticizer widely used in plastic products, phthalates are not covalent bonded, but are connected by Van Der Waals force or hydrogen bonds. Thus they easily break away from the plastic and migrate to external environment, causing environmental pollution.This experiment points to degrade dimethyl phthalate(DMP) with upflow anaerobic sludge blanket (UASB) Reactor, and do research on the effect of anaerobic granular sludge to the DMP's treatment result,.Through the course, the best operating parameters for degradation is found.In the rejuvenation stage, the anaerobic granular sludge formed under normal-temperature conditions, are usually the seed sludge, which can effectively and quickly start the UASB reactor. In the domestication stage, adding glucose as co-substrate of DMP can effectively improve DMP's biodegradability. In the degradation process where DMP is the single matrix, it's found that DMP has not been fully mineralized, and some are degrated into phthalate esters and other intermediates, resulting in a larger COD in effluent.In the degradation process where DMP is the single matrix, the limit DMP concentration that UASB reactor can treat in room temprature and medium temprature separately lies in the range of 600-750 mg/L and 500-600 mg/L. During recovering sludges'activity, the application of glucose as co-substrate plays a very positive role.The study makes comparisons on the operating parameters in two different temperature, and finds the best operating parameters for DMP's degradation: in medium temperature, when the DMP concentration in influent is 600mg / L, HRT is 8h, which means the corresponding volume load is 3.11gCOD / L·d, the removal rate of DMP is 97%, that of COD is 91.33%; in room temperature, the optimal condition is that the influent's DMP concentration is 500mg / L, HRT is 8h, with a 2.60gCOD / L·d corresponding volume load, as a result, the DMP removal efficiency amounts to 96%, and the COD removal rate is 90.75%.By comparing, the normally-operated UASB reactor in medium tempetarue runs a faster degradation rate, and achives higher gas production with ability to treat DMP in higher concentration than that in room temperature, but the difference is indistinctive. Through the combination of the model's derivation with the test data, the dynamics model of DMP's degradation in medium temperature and in room temperature is separately established. By analysis, it is found that, for the stable UASB reactors, there is a highly significant correlation in the model and the experimental data. As a result, the dynamics model is reliable.