Preparation method and use of Fe-Al compound dephosphorizing absorbent and application thereof

Abstract

The invention relates to a method for preparing composite ferro-aluminum dephosphorize absorber, and relative application, wherein said method comprises that: mixing FeCI3 and AICI3 solutions; adding NaOH solution, while their mol ration is 3:2:14; laying and filtering out the product; washing with water until the water outlet is neutral; drying at 100-110Deg. C to prepare the particle absorber. And relative application comprises that: adding adsorption dephosphorize technique into the general water treatment, while said technique is formed by 2-4 serial dephosphorize adsorption pools whose structure are same as filter pools; and using particle composite ferro-aluminum dephosphorize absorber as filter material while its diameter is 0.5-0.8mm, the thickness of adsorption is 1. 0-1. 5m, the load of adsorption pool is 5m / h-8m / h, and the empty bed contact time is 30-40min. The inventive absorber has wide application, simple regeneration and low cost.

Description

technical field [0001] The invention belongs to the field of environmental protection, and in particular relates to an adsorption phosphorus removal technology for drinking water source water and urban sewage treatment plant discharge water. Background technique [0002] In recent years, due to the key role of phosphorus on the reproduction and growth of microorganisms, countries all over the world have paid special attention to the control of phosphorus content in water bodies. Studies have shown that phosphorus is one of the elements that have a significant limiting effect on microbial regrowth in pipe network systems. For most water quality, when the total phosphorus concentration is lower than 1 μg / l, phosphorus will become a limiting factor for microbial growth in water, so It is of great significance to reduce the phosphorus content in the effluent water as much as possible in the water supply treatment to ensure the sanitation and safety of drinking water. In additio...

AI Technical Summary

Problems solved by technology

Among them, the biological method of phosphorus removal is based on the principle of phosphorus uptake and release by phosphobacteria, and dephosphorization is achieved through aerobic-anaerobic alternate operation. This method has the advantages of low operating costs and can remove organic pollutants in water. The disadvantage is that the process has poor stability. , the operation is strict, and affected by the temperature and pH of the wastewater, it has a strong dependence on the concentration of organic matter in the water. When the concentration of organic matter in the water is low and the content of phosphorus is high, it is difficult to meet the phosphorus discharge standard, and the content of phosphorus in the source water for water treatment is low. Usually below 100μg / l, it is also difficult to carry out traditional biological phosphorus removal

Chemical phosphorus removal mainly refers to the method of using metal ions produced by iron salts, aluminum salts and lime and phosphate to form insoluble phosphate precipitates to remove phosphorus in water. This method is reliable in operation and can achieve a high phosphorus removal rate. However, this process is a precipitation-dissolution equilibrium reaction process. In order to achieve a high phosphorus removal rate, especially the extremely low phosphorus content in the feed water source, in order to achieve the conditions for phosphate precipitation, it is necessary to add a higher metal ion precipitant, thus It leads to a substantial increase in the cost of chemicals, and at the same time, the content of residual metal ions in the effluent increases, and the chroma increases. In addition, the generated sludge has a large water content, which is difficult to handle and is likely to cause secondary pollution.

In addition, the common disadvantage of biological and chemical phosphorus removal is that neither of them can carry out phosphorus recovery.

[0004] Phosphorus removal by adsorption method is to use the large specific surface area provided by the adsorbent to separate phosphorus from water through the process of adsorption, ion exchange or surface precipitation of phosphorus on the surface of the adsorbent. The adsorption-desorption method can realize the elimination of phosphorus pollution in wastewater At the same time, the purpose of reclaiming phosphorus resources and turning waste into treasure, so adsorption phosphorus removal has been developed in the field of wastewater treatment, and various types of adsorbents have emerged, among which activated alumina is a traditional adsorbent, which is widely used at present, but the adsorption capacity Not high enough, short operating cycle

In addition, as an efficient and low-consumption method for removing specific solutes from low-concentration solutions, adsorption phosphorus removal is more suitable for the removal of trace phosphorus in drinking water. However, the role of phosphorus in drinking water has not been fully understood and valued for a long time. , has not been able to be associated with the quality of drinking water, especially the biological stability of drinking water, so there has been no report on the method of removing trace phosphorus in water by adsorption. In addition, the requirements for phosphorus removal in drinking water are very different from those in sewage. In particular, there are great differences in the limit content, and the phosphorus removal adsorbents that may be used are also greatly constrained by the water treatment process and water quality requirements. The environment and improving water supply security are both important