Urban sewage treatment of anaerobic biological-low voltage electric field oxidizing coupling system

Abstract

An urban sewage treatment from anaerobic biological-low voltage electric field oxidation coupling system is carried out by taking coupling system with expanding anaerobic particle mud bed reactor and low-voltage electric field reactor, turning on low-voltage electric field reactor when outfall ammonia nitrogen of anaerobic reactor above discharge standard, ammonia nitrogen oxidizing by electrochemical method below discharge standard, turning off reactor of low-voltage electric field, treating sewage by anaerobic reactor and discharging directly. It can achieve national discharge standard.

Description

technical field [0001] The invention belongs to the technical field of environmental protection, and in particular relates to a method for oxidizing urban sewage with a low-voltage electric field after biochemical treatment in an anaerobic reactor so that COD and ammonia nitrogen can simultaneously reach the standard. Background technique [0002] Anaerobic biological treatment has: (1) simple construction, operation and operation, low cost of infrastructure and operation; (2) low energy demand, energy saving; (3) large elastic range of treatment scale, making decentralized treatment possible; ( 4) It has the advantages of less generation of excess sludge, good stability, good dehydration performance, and easy post-treatment, so it has been widely used in the treatment of high-concentration organic wastewater. The advantages of anaerobic biological treatment meet the requirements of new technologies for urban sewage treatment, but it has its own shortcomings. For example, i...

AI Technical Summary

Problems solved by technology

Research and engineering practice show that this method has high and stable denitrification efficiency, but it has the following defects: (1) Carbon sources need to be added to the denitrification tank, the cost of chemicals is high, and the dosage is difficult to control, which may easily cause organic matter Leakage; (2) Due to the need to add chemicals and automatic online monitoring and control, there are many equipments, high operation requirements, complicated management, and high quality requirements for operators; (3) All carbon in the influent water needs to be oxidized into CO 2 and H 2 O, the hydraulic retention time is long, the pool volume is large, the floor area is large, and the infrastructure cost is high; (4) The power consumption of aeration is high; (5) Because it is a biological treatment, it must be operated continuously, and it cannot be started or stopped at any time according to the change of water quality. , not flexible enough

It is the anoxic denitrification tank in the front, the aerobic nitrification tank in the back, it uses the organic matter in the influent as the denitrification carbon source, overcomes the defect that the O / A method needs to add chemicals as the denitrification carbon source, but it It also inevitably has the following defects: (1) A large amount of mixed liquid needs to be refluxed to improve the denitrification efficiency, and the reflux ratio is usually required to be 7-8:1, so the energy consumption is large and the operating cost is high; (2) The denitrification efficiency is low; (3) The effluent contains a certain concentration of nitrates. In the secondary settling tank, denitrification may occur, causing the sludge to float up and affecting the quality of the effluent.

Although the fixed growth of microorganisms on the membrane is beneficial to the growth of autotrophic nitrifying bacteria with a long generation time, there are also some defects as follows: (1) the use of fillers greatly increases the investment cost and the cost is high; (3) the denitrification efficiency Low; (4) Membrane shedding is easy to cause blockage; (5) Water distribution is not easy to be uniform; (6) Growth of pond flies, etc.