光催化转化并回收水中农药有机磷

Photocatalytic conversion and recycle of organic phosphorus within pesticides form aqueous solution

经溶胶-凝胶法制备不同镧(La)掺杂量的二氧化钛(TiO2),得到光催化转化吸附回收有机磷的复合材料.结果表明,La与TiO2掺杂物质的量比为0.002并经过煅烧和掺杂物质的量比为0.02未经煅烧的2种材料,以6:4的比例混合,所得复合材料La@TiO2(6:4)为粒径约13nm的锐钛矿型TiO2,表面有球形聚集体但分布较均匀,其光谱范围较纯TiO2发生红移,因而光催化效率提高.当有机磷浓度20mg/L、La@TiO2(6:4)投加量为1g/L、溶液p H值为9时,有机磷回收率最高达85%.溶液中的NO3-、Cl-、SO42-对磷回收影响不大,CO32-有抑制作用;材料经解吸后可多次重复利用.研究表明La@TiO2(6:4)为有前景的有机磷回收复合材料.

Titanium dioxide(TiO2) doped with different amounts of lanthanum(La) were prepared by using sol-gel method. The composite materials obtained can be photocatalyzed to convert and recover organic phosphorus. By mixing a calcined lanthanum-TiO2 composite material with a molar ratio of 0.002 with that at a molar ratio of 0.02 without calcination at a weight ratio of 6:4, a composite material named La@TiO2(6:4) was finally obtained. It had a crystal structure of anatase TiO2 with a particle size of about 13 nm, and had a surface withspherical aggregates which were uniformly distributed. The light utilization map range of this material was red-shifted as compared to pure TiO2, which resulted in spectrum utilization range expansionthusphotocatalytic efficiency improvement. The phosphorus recovery was up to 85% when 1g/L La@TiO2(6:4) dosage was employed at a initial organic phosphorus concentration of 20 mg/L, and the pH of 9. No obvious effect of NO3-、Cl-and SO42-in solution on phosphorus recovery was observed, but CO32-negatively affected the phosphorus recovery. The La@TiO2(6:4) material can be reused for many times after desorption.The reaserch showed that La@TiO2(6:4) is a promising organic phosphorus recycling composite.