Nitrogen Removal Efficiency and Engineering Application of a New Composite Carbon Source
Insufficient of carbon sources is a common problem in wastewater treatment plants(WWTPs).Low-cost and efficient carbon sources are essential for improving effluent nitrogen removal efficacy as well as reducing wastewater treatment costs.This paper has investigated the waste water denitrification effciency and economy of a new type of ethylene glycol composite carbon source(EGC)through laboratory trial and practical engineering application.The results show that the denitrification rate of EGC is comparable to that of sodium acetate and it can promote complete denitrification.In the practical application of WWTP EGC can maintain the effluent of total nitrogen(TN)and chemical oxygen demand(CODCr)stable discharge.The sludge L-EPS decreased from 23.14 m g/(g SS)before carbon source replacement to 9.16 mg/(g SS)after replacing with EGC,and the sludge volume index(SVI)decreased from 121 mL/g to 71 mL/g.The correlation study shows a positive correlation between the L-EPS content and the change of SVI with a correlation curve of y=2.72x+63.51(R2=0.689),which indicates that the long-term use of the EGC carbon source does not lead to the reduction of sludge settling performance or induce sludge swelling and other Problems.Furthermore,the average cost of using the EGC carbon source is only 0.04 yuan/m3,86.2％lower than that of glucose,and the average sludge yield is only 0.70 g/g,17.6％lower than before replacement,showing excellent economic applicability and promising prospects for large-scale application.
万方数据
维普
