Integrated Process Research On Power/Material/Sludge Reduction Of Large Wastewater Treatment Plant

At present, energy and resources are badly needed , so sustainable development has become people's popular topic. under the guide of principles of clean production,cycle economy and sustainable development the domestic the largest industry waste water treatment mill —Shaoxing Wastewater Treatment Plant (WWTP) at the scale of 600,000 m³/d was selected to investigate, the technique of energy saving have been carried out on every segment, the results will benefit to resolve the confronted hardship , and go through the predicament.First of all, the running situation of the WWTP has been surveyed . By means of analyzing the technological process , technology parameter , influent and effluent water quality , sludge yield , material consumption , running cost, and so on , it was found out that he shortcoming of present technology were mainly disqualifications of COD_Cr and chrominance , furthermore, the existing problems still include the follows: the amount of water handling can not reach the design scale, residual sludge can not be proper processed, t the electricity cost high, coagulant consume too much, recycling use of the material and discarded object have not be considered. These problems are the bottleneck of WWTP running economically.Secondly , combined the WWTP technological process with the existing problems , four key spots were investigated to realize energy saving and filth reducing . (1) By means of analyzingoriginal water quality in detail, it was found that organic contaminants in this wastewater were not easily be reduced by biochemistry, origination dissolving quality of inertia organic matter reach 120 mg/L, this result indicates that suitable pretreatment must be intake to improve B/C, reduce alkalinity and pH value , reduce S_I and poisonous substance content that will go into biochemistry system (2), In the segment of anaerobic technology, the techniques of EGSB,ABR, ASBR, three kind of difference anaerobic reactor, were adopted and different parameters were investigated in detail. Anaerobic reactors were mainly including hydrolysis and caliphate reduction, methane gas could't form. The main contaminant- acid terephthalic acid(TA) could't be effectively cleaved cycle and further degraded. Anaerobic reduced 200-450 mg/L of COD. after adopting separately ABR and ASBR, energy saving was obvious. (3), The control of the amount feeding oxygen is the key parameter to achieve energy saving. The dissolved oxygen (DO) fluctuated greatly and was unreasonable distribution, after introducing intellect feed the oxygen system (MASTERAIR), DO could keep a stable value and distributed reasonably. This technique can save electricity 18.71% (4), The decrement was cut down by reducing, stabilization and mineraliztion of the trash of the WWTP, a the technology process of burning sludge was adapted to treat the sludge, and the incinerated sludge was recycled as reagent.Finally, after adopting relevant researching results, a 700,000 m³/d reconstruction project was performed, and the reducing cost per 1 m3 reach 0.12 yuan, thus this reconstruction project saves the operating cost more than 3000 thousand yuan each year in WWTP.