Preparation method of nano hydroxylapatite adsorbent for absorbing heavy metal ions in waste water

Abstract

The invention discloses a preparation method of a nano hydroxylapatite adsorbent for absorbing heavy metal ions in waste water, comprising the following steps of: 1. preparing a precursory solution containing calcium and a precursory solution containing phosphorus: respectively preparing calcium nitrate with the concentration of 0.1-1mol / L and a phosphoric acid solution with the concentration of 0.1-0.5mol / L, and dropwise adding ammonia into the phosphoric acid solution, wherein the pH value is 10-12; 2. dropwise adding the precursory solution containing calcium into the precursory solution containing phosphorus, stirring to obtain a solution with white sediments, controlling the pH value constantly at 10-12; carrying out post-aging for 5-24h to obtain gel; and 3. placing the gel into a drying oven to dry at 55-100 DEG C for 10-24h to obtain xerogel, washing the xerogel by using distilled water 3-5 times, ball-milling for 12-24h, drying at 100 DEG C for 6-10h, calcining at 500-900, and preserving the heat for 2-6h to obtain the nano hydroxylapatite adsorbent. The invention has the characteristics of low cost, simple process and high adsorption efficiency.

Description

technical field [0001] The invention belongs to the technical field of heavy metal sewage treatment, in particular to a preparation method of an adsorbent composed of apatite. Background technique [0002] Heavy metal wastewater mainly comes from mining, mineral processing, smelting, electroplating, chemical industry, tanning and papermaking industries, etc. Heavy metals such as lead, mercury, chromium, cadmium, nickel, copper and zinc produced by these industries account for a considerable proportion of industrial wastewater , and it is difficult to handle, causing serious environmental pollution and waste of resources. The development of heavy metal wastewater treatment technology is not only beneficial to environmental protection, but also can promote industrial development and the progress of human society. [0003] In terms of remediation and treatment of heavy metal pollution in water, chemical precipitation methods, ion exchange methods, electrolysis methods, biologi...

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Problems solved by technology

At present, the adsorption properties of natural hydroxyapatite, synthetic hydroxyapatite, and modified hydroxyapatite such as carbon hydroxyapatite have been studied at home and abroad (F.Fernane et al., Materials Science and Engineering C, 2010 , 30:1060-1064; Zizhong Zhang et al., Environmental Pollution, 2010,158:514-519; Chinese patent, application number 200910088835.6), but its artificial synthesis is relatively complicated, the adsorption capacity is small, and the adsorption rate is slow. Wide application of hydroxyapatite

At present, the methods for preparing hydroxyapatite mainly include: precipitation method, hydrothermal method, microemulsion method, self-combustion method, etc. These methods have more or less disadvantages such as high cost, complicated preparation process, long cycle, and harsh conditions.

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