Zeolite synthesized from fly ash and a method for treating high-concentration ammonia-nitrogen wastewater by zeolite

Abstract

The invention relates to the field of sewage treatment, in particular to zeolite synthesized from fly ash and a method for treating high-concentration ammonia-nitrogen wastewater by zeolite. The preparation method of zeolite comprises the step of pretreatment, that is, fly ash is washed and pickled sequentially, and washed-pickled fly ash is obtained; particularly, during washing, the fly ash is evenly mixed with pure water and stirred at 15-30 DEG C for 48 h, and washed fly ash is obtained by solid-liquid separation; during pickling, the washed fly ash and a 2 mol / L HCl solution are mixed ina volume ratio of 1:9, the mixture is stirred at 80 DEG C for 1 h, then solid-liquid separation, washing with water, washing with alcohol and drying are performed, and the washed-pickled fly ash is obtained. Zeolite is pretreated by pickling and water washing pretreatment, so that the ammonia-nitrogen removal rate of zeolite is higher than that of zeolite pretreated by pickling only, and is much higher than that of zeolite pretreated by water washing only; compared with direct pickling, the consumption of hydrochloric acid is reduced by 18.18% and the preparation cost is reduced.

Description

technical field [0001] The invention relates to the field of sewage treatment, in particular to a zeolite synthesized by using fly ash and a method for treating high-concentration ammonia-nitrogen wastewater. Background technique [0002] Ammonia nitrogen is one of the important reasons leading to eutrophication of water body. Therefore, the control of nitrogen load in wastewater, especially high concentration ammonia nitrogen wastewater treatment is particularly critical. High-concentration ammonia nitrogen wastewater mainly comes from industrial wastewater and aquaculture wastewater. According to the Announcement of the First National Survey of Pollution Sources (2010), the discharge of various source water pollutants was 1.7291 million tons of ammonia nitrogen and 4.7289 million tons of total nitrogen. Among them, the annual ammonia nitrogen production of industrial wastewater is 2.0167 million tons, and the ammonia nitrogen actually discharged into the environmental wat...

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Problems solved by technology

[0004] When high-concentration ammonia nitrogen industrial wastewater is treated by biochemical methods, on the one hand, due to the poor buffering capacity of high ammonia nitrogen wastewater, a large amount of alkalinity needs to be added to maintain the pH value of the system; on the other hand, high concentration of free ammonia will inhibit the activity of microorganisms, resulting in biological Low treatment efficiency is a major difficulty in industrial wastewater treatment

In addition, the lack of carbon sources further limits the denitrification process, which leads to the poor denitrification effect of the traditional biological deammonization process for treating high-ammonia nitrogen wastewater. In the process of industrial wastewater treatment, the concentration of ammonia nitrogen in the effluent remains high or the treatment efficiency is not stable. The situation is ubiquitous, and it is difficult to discharge high-concentration ammonia nitrogen wastewater up to standard by using biochemical treatment alone

When the high-concentration ammonia nitrogen industrial wastewater is biochemically treated, it is usually necessary to dilute the wastewater and other physical and chemical pretreatments to make the ammonia nitrogen concentration at 300mg L -1 Subsequent biological treatment is performed even lower, which substantially increases the total amount of wastewater

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