作　　者： (张梦媚）; (何世颖）; (唐婉莹）; (冯彦房）; (杨林章）;

机构地区： 江苏省农业科学院农业资源与环境研究所,江苏南京210014 南京理工大学化工学院,江苏南京210094

出　　处： 《环境科学研究》 2017年第9期1440-1447,共8页

摘　　要： 为研究功能复合材料对低浓度氨氮[ρ(NH_4^+-N)≤50 mg/L]废水的处理效果,采用水热法制备TiO_2/生物炭复合材料,并在自制光催化反应装置中对低浓度氨氮废水进行处理,考察TiO_2负载量、温度、pH等因素对NH_4^+-N去除过程的影响以及催化的最终降解产物.结果表明,TiO_2/生物炭复合材料能有效催化去除废水中的NH_4^+-N,其优化处理条件:ρ(NH_4^+-N)为50 mg/L,TiO_2/生物炭复合材料投加量为1.5 g/L,254 nm紫外灯照射120 min,TiO_2负载量为20%,废水初始pH为11.0,曝气量为150 mL/min.在优化处理条件下,当温度为60℃时NH_4^+-N去除率可达100%,常温(30℃)下可达67%.反应最终产物中ρ(NO_2^--N)非常低,并且无NO3--N生成.研究显示,TiO_2/生物炭复合材料具有将NH_4^+-N转化为N2的良好光催化氧化选择性. In order to investigate the disposal of low concentration ammonia-nitrogen wastewater （ concentration less than or equal to 50 mg/L） using a functional composite, a new photocatalyst, TiO2/biochar composite, was prepared by immobilizing TiO2 nanoparticles onto biochar synthesized by the hydrothermal method. The properties of the as-prepared TiO2/biochar were further characterized by X-ray diffraction, scanning electron microscopy, and UV-Vis diffuse reflectance spectroscopy. The photocatalytic degradation of ammonia- nitrogen from water was evaluated along the gradients of load rat io, pH, temperature and initial concentrations of ammonia-nitrogen. The results showed that TiO2 nanoparticles were well dispersed on the biochar, which prevented the agglomeration of TiO2 and enhanced the instability. The highest ammonia-nitrogen removal efficiency （ 100% at 60℃ and over 70% at 30 ℃ ） was observed at the conditions of 20% TiO2 loading, 150 mL/min aeration rate, pH 11.0, and under 254 nm UV light irradiation. The final product contained little nitrite and exclusive ni trate, indicating the excellent catalytic selectivity of TiO2/biochar composite, which can oxide ammonia-nitrogen to N2. In conclusion, TiO2/biochar composite is anenvironmentally-friendly and highly efficient photocatalyst complex for the removal of ammonia- nitrogen at low concentrations.

关 键 词： 生物炭 低浓度氨氮废水