A device and method for treating ammonia nitrogen wastewater

Abstract

The invention discloses a device for processing ammonia-nitrogen wastewater and a method thereof. In a membrane contactor, sweep gas is used for bringing out ammonia molecules passing through a hydrophobic microporous hollow fibrous membrane from a raw water side and introducing the ammonia molecules into a microalgae cell solution; and the microalgae cell solution absorbs ammonia in the sweep gas to promote growth of microalgae cells. Ammonia-nitrogen in wastewater is removed and microalgae cell biomass is obtained. The microalgae cells can be repeatedly used for absorbing ammonia-nitrogen in wastewater and also can be used for production of novel green energy after being collected. Existing chemical and biological nitrogen-removal methods are improved, operational difficulty and maintenance cost are reduced, and potential safety hazard is eliminated. By the use of the sweep gas, operation of the device at the wastewater side can be more flexible and convenient and is not restrained. Harmful substances in wastewater can be effectively prevented from inhibiting growth of microalgae and affecting the ammonia-nitrogen removal effect.

Description

technical field [0001] The invention relates to a device and method for treating ammonia nitrogen wastewater, in particular to using a liquid-gas membrane contactor to separate ammonia nitrogen in wastewater, and using a microalgae cell solution to absorb the ammonia carried in the purge gas as a nitrogen source required for its growth . Background technique [0002] The main source of ammonia nitrogen wastewater is the production process of petrochemical, chemical metallurgy, food and pharmaceutical industries and landfill leachate. According to the concentration of ammonia nitrogen, wastewater can be divided into three categories: high concentration (>500ppm), medium concentration (50-500ppm) and low concentration (<50ppm). In general, most industrial wastewater and domestic sewage are low-concentration ammonia-nitrogen wastewater. At present, the more common treatment methods are biological denitrification and physical and chemical methods. However, due to the co...

AI Technical Summary

Problems solved by technology

However, the concentration of ammonia nitrogen that can be treated by this patent is low, only 20ppm; although it can completely remove ammonia nitrogen in sewage, the treatment time is longer (6 days)

In addition, the gel beads formed by sodium alginate and calcium chloride contain other metal ions (such as Mg 2+ ) in sewage, Ca 2+ It will be gradually replaced by other ions (about 2 days), causing the strength of the pellet to decrease, and then rupture

The microalgae cells in the pellet will also continue to divide and grow, affecting the internal structure of the pellet, making it impossible to reuse for a long time

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