A nitrification-denitrification two-phase expanded-bed reactor and a sewage treating process

Abstract

A nitrification-denitrification two-phase expanded-bed reactor and a sewage treating process are provided. The expanded-bed reactor comprises a reactor, an oxygen dissolving machine, a circulating pump and auxiliary pipelines. The reactor has a vertical cylindric structure, and comprises a bottom water distribution zone, an aerobic reaction zone, a secondary water distribution zone, an anoxic reaction zone and a water discharging zone from bottom to top. The aerobic reaction zone and the anoxic reaction zone are filled with small-particle-size fillers. The secondary water distribution zone is provided with a shrinkage-expansion type collector ring. The water discharging zone is provided with a three-phase separator. Through adoption of the expanded-bed reactor, nitrification and denitrification are performed in the reactor, biochemical and oxygen dissolving processes are performed independently, a biochemical treating load is high, the floor space of equipment is small and investment and a running cost are saved.

Description

technical field [0001] The invention relates to the technical field of sewage treatment, and more specifically relates to a nitrification and denitrification two-phase expanded bed reactor for advanced treatment of sewage and a sewage treatment process. Background technique [0002] Nitrification and denitrification is the most commonly used biochemical process for sewage denitrification treatment. Nitrification is to oxidize ammonia nitrogen in sewage to nitrate through microbial aerobic biochemical reaction, and denitrification is to reduce nitrate to nitrogen through microbial anoxic biochemical reaction. [0003] Commonly used sewage denitrification can be divided into two types: pre-denitrification and post-denitrification. Pre-denitrification requires a large amount of mixed liquid reflux, and the denitrification efficiency is limited. After the nitrification unit, facilities for further removal of organic matter are installed. Both of these two denitrification proces...

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Problems solved by technology

But this three-phase fluidized bed still has certain deficiencies: (1) The internal circulation flow depends on the air supply volume, and the dissolved oxygen volume also depends on the air supply volume. In order to realize the fluidization of the packing, the air supply volume must be large enough, and the reactor Dissolved oxygen is usually difficult to control at a lower concentration required for denitrification; (2) The driving energy source of the internal cycle is the work of gas expansion during the rising process, and the energy utilization rate is low, resulting in high operating costs

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