竞争性阳离子对粉煤灰合成沸石除氨氮的影响

研究了四种竞争性阳离子(K+、Na+、Ca2+、Mg2+)对三种改性粉煤灰合成沸石(Na沸石,Ca沸石,Al沸石)除氨氮能力的影响,并测定了合成沸石对四个湖泊水样(太湖、巢湖、洱海、抚仙湖)中氨氮的去除效果。结果表明,与Na+、Ca2+、Mg2+比较,K+对合成沸石除氨氮影响大得多;而前三者的影响大小的顺序为Na+Ca2+Mg2+。在纯水中,或不同竞争性阳离子存在下,或天然湖泊水样中,Al沸石和Ca沸石对氨氮的去除能力均远高于Na沸石。太湖和巢湖主要含Na+和Ca2+;洱海水样主要含Ca2+;抚仙湖水样主要含Ca2+和Mg2+;但四个湖泊水样中K+的浓度均为最低。Al沸石和Ca沸石对四个天然湖泊水样中的氨氮具有良好的去除效果,去除率达77%～90%。

Effect of Competitive Cations on the Removal of Ammonium by Zeolite Synthesized from Coal Fly Ash

The effects of four competitive cations includin K~+, Na~+, Ca~(2+), Mg~(2+) on the removal of ammonium by three modified zeolites synthesized from coal fly ash (Na-, Ca- and Al- zeolite) have been investigated. The removal of ammonium from four lake water samples such as Taihu, Chaohu, Erhai and Fuxianhu by the synthesized zeolites was measured. It was shown that compared with Na~+, Ca~(2+), and Mg~(2+), K~+ had a much higher negative effect on ammonium removal by zeolites. The competitive effects of the former three cations for ammonium removal followed the order of Na~+>Ca~(2+)>Mg~(2+). Ca- and Al- zeolite had much greater ability for ammonium removal than Na-zeolite in pure water, in the coexistence of competitive cations, as well as in natural lake water samples. Taihu and Chaohu contained mainly Na~+ and Ca~(2+); Erhai contained mainly Ca~(2+); Fuxianhu contained mainly Ca~(2+) and Mg~(2+); but the concentration of K~+ in all lake water samples is the lowest Ca- and Al- zeolite had sufficiently good removal performances for ammonium from the four lake water samples, with the removal efficiencies from 77% to 90%.