粉煤灰和C_3N_4复合材料对含铬废水的处理

Treatment of Wastewater Containing Cr^(6+) with Fly Ash and C_3N_4

粉煤灰是中国主要的工业废弃物之一,粉煤灰是一种多孔性、具有较大比较面积的固体颗粒,具有一定的吸附能力,可用于重金属的处理,起到以废制废的效果。C_3N_4作为一种非金属可见光响应新型的光催化剂,在光催化研究方面广泛用于降解重金属废水。本文通过研磨混匀处理制成粉煤灰和C_3N_4的复合材料。单因素试验使用粉煤灰和C_3N_4复合材料处理含铬废水,并对操作条件进行选择和优化,单因素试验结果表明,当粉煤灰和C_3N_4投加量40g/L,pH值2,吸附时间40 min,吸附剂配比为C_3N_4含量为5%的条件下,Cr6+去除率可达89.2%。对比试验发现粉煤灰和C_3N_4复合材料的去除效果优于纯粉煤灰。碱改性粉煤灰的去除率能达到92%以上,而粉煤灰和C_3N_4复合材料的去除率略低于90%,进一步研究考虑使用其他方式制备复合材料。

Fly ash is one of the main industrial wastes in China. Fly ash is a kind of porous, with a largearea of solid particles, so it has a certain adsorption capacity. It can be used for the treatment of heavy metals, by using waste to treat waste effect. As a kind of non-metal novel visible light photocatalyst, C3N4 is widely used in the study of photo- catalytic degradation of heavy metal waste water. In this paper, the composite material of fly ash and C3N4 is pre-pared by grinding and mixing process. The operating condition of Cr6＋ removal from water by fly ash and C3 N4 has been compared and optimized by single-factor experiment methods. The single-factor experiment results show that when the dosage of the material is 40g/L, pH 2, and the adsorption time is 40rain, the adsorbent ratio of C3 N4 is 5% ,the removal rate of Cr6＋can reach 89.2%. By comparing the experimental results of fly ash and C3N4 and pure fly ash the removal effect of the composite material in fly ash and C3N4 is much better than that in the pure fly ash. The removal rate of alkali modified fly ash can reach above 92% , and the removal efficiency of fly ash and C3 N4 composites was slightly lower than 90%. Therefore, further studies consider the use of other methods for the preparation of composite materials.