Iron-aluminum-manganese composite metal oxide adsorbent for removing phosphate from water and preparation method thereof

Abstract

The invention belongs to the field of water treatment, and in particular relates to an iron-aluminum-manganese composite metal oxide adsorbent for efficiently removing phosphate from water and a preparation method thereof. The iron-aluminum-manganese composite metal oxide adsorbent for removing phosphate from water is prepared from raw materials including ferrite, an aluminum salt and permanganate through an oxidation-reduction and coprecipitation method, and comprises the components including hydroxyl iron oxide hydrate, hydroxyl aluminum oxide hydrate, manganese oxide hydrate and the like. The iron-aluminum-manganese composite metal oxide adsorbent has rich surface activity adsorption sites and high isoelectric points (IEP>8.5). The electrostatic adsorption of composite metal oxides to the phosphate in water is strengthened by using synergistic action of all component metal oxides. The iron-aluminum-manganese composite metal oxide adsorbent provided by the invention can be used for removing phosphate from reservoirs, rivers, lakes, drinking water and urban sewage, and can also be used for removing contaminants including arsenate, selenate, fluorine ions and the like.

Description

technical field [0001] The invention belongs to the field of water treatment, in particular to an iron-aluminum-manganese composite metal oxide adsorbent for efficiently removing phosphate in water and a preparation method thereof. Background technique [0002] Phosphorus is an important factor causing water eutrophication. In natural water and wastewater, phosphorus mainly exists in the form of various phosphates, including orthophosphate (SRP), polyphosphate and organic phosphate (SUP). Among them, dissolved orthophosphate is generally considered to be the main form used by algae, which belongs to the biologically available phosphorus and needs to be effectively removed. [0003] Common water treatment phosphorus removal technologies include: biological method, chemical precipitation method, adsorption method and membrane method. The biological method has strict requirements on the operating conditions of phosphorus removal due to the growth sensitivity of microorganisms,...

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Problems solved by technology

[0006] It is generally believed that the complex adsorption capacity of iron oxides to phosphate is relatively high. The inventors of this case had prepared an iron-manganese composite oxide phosphorus removal adsorbent in the early stage and found that although the phosphorus adsorption capacity of manganese oxides is very low, due to the manganese The intercalation of oxides, the surface active adsorption sites of the prepared iron-manganese composite metal oxides are significantly increased, so its complex adsorption capacity is significantly higher than that of single iron oxides and manganese oxides.

However, the isoelectric point (IEP, isoelectric point) of iron-manganese composite oxides is relatively low (about 6.6), and it is difficult to ensure that the surface of the adsorbent has positive charge, thereby reducing its electrostatic adsorption to negatively charged phosphates on the surface