Method for treating nitrogen-containing wastewater from power plants by nitrifying bacteria immobilized on polyurethane

Abstract

The invention discloses a method for treating nitrogen-containing wastewater from power plants by nitrifying bacteria immobilized on polyurethane, comprising the following steps: (1) separating and screening high-efficiency dominant nitrifying bacteria from a nitrogen removed sewage treating system which runs for more than 1 year and domesticating and carrying out enlarge culture on the dominant nitrifying bacteria; (2) immobilizing the nitrifying bacteria on soft polyurethane foam packing by the immobilization technology combining embedding and adsorption and adding the nitrifying bacteria to a fluidized bed reactor, wherein the volume of the added nitrifying bacteria accounts for 25-35% of the active volume of the reactor and the bacteria addition is 1g of wet strains per 150mL of packing; and (3) adopting intermittent culture at the early stage of running of the reactor, ensuring the inlet water to be the domestic sewage and adding nutrient substances, controlling the mass ratio of C:N:P to be 100:15-20:1, after intermittent running for 10d, the sewage treating system beginning normal running to carry out sewage denitrification when less polyvinyl alcohol in water is dissolved out (less foam or nearly no foam exists on the liquid level). The method of the invention improves the sewage denitrification efficiency.

Description

technical field [0001] The invention relates to a treatment method of nitrogen-containing wastewater, in particular to a method for treating nitrogen-containing wastewater of a power plant by immobilizing nitrifying bacteria with polyurethane. Background technique [0002] In my country's primary energy composition and consumption, coal accounts for as much as 70%. Among them, coal-fired power plants are the largest coal-consuming and sulfur dioxide and nitrogen oxide emissions in my country. Therefore, to control the emission of sulfur dioxide and nitrogen oxides from coal-fired power plants, It is one of the tasks in the field of air pollution control in my country. By the end of 2007, about 50% of the country's thermal power units had installed flue gas desulfurization devices, and many coal-fired power plants had installed denitrification equipment to reduce nitrogen oxides (NO x ) and sulfide (SO x ) emissions, but these denitrification and desulfurization devices will...

AI Technical Summary

Problems solved by technology

[0004] Ordinary activated sludge process enters a stable period after the system has been running for a period of time. At this time, the removal efficiency is basically stable, and with the extension of the reaction time, the removal efficiency increases slowly, which reduces the efficiency of sewage denitrification treatment.

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