改性石榴皮生物炭对水中低浓度硝氮的吸附性能研究
王 怡1,2,3,陈琳风1,王文怀1,冯琳琳1,柴宝华1,范 攀1,丁 卓1,云斯宁4,徐鸿飞4

(1.西安建筑科技大学 环境与市政工程学院,陕西 西安 710055; 2.西安建筑科技大学 陕西省环境工程重点实验室,陕西 西安 710055; 3.西安建筑科技大学 西北水资源与环境生态教育部重点实验室,陕西 西安 710055; 4.西安建筑科技大学 材料科学与工程学院 功能材料研究所,陕西 西安 710055)

石榴皮; 生物炭; 改性; 低浓度硝氮; 吸附

Adsorption behavior of low concentration nitrate nitrogen from water by modified biochars from pomegranate peel
WANG Yi 1,2,3, CHEN Linfeng1, WANG Wenhuai1, FENG Linlin1, CHAI Baohua1, FAN Pan1, DING Zhuo1, YUN Sining4, XU Hongfei4

(1. School of Environmental and Municipal Engineering, Xi'an Univ. of Archi. & Tech., Xi'an 710055,China; 2. Shaanxi Key Laboratory of Environmental Engineering, Xi'an Univ. of Arch. & Tech., Xi'an 710055, China; 3. Key Laboratory of Northwest Water Resource, Environment and Ecology(MOE), Xi'an Univ. of Arch. & Tech., Xi'an 710055, China; 4. Laboratory of Functional Materials, School of Materials Science and Engineering, Xi'an Univ. of Arch. & Tech., Xi'an 710055, China)

pomegranate peel; biochar; modification; low concentration NO3--N; adsorption

DOI: 10.15986-j.1006-7930.2019.06.018

备注

以石榴皮为原料在不同条件下制备生物炭,并对其进行盐酸改性,对比改性前后生物炭性质及其对硝氮的吸附效果.SEM、FTIR及等电点测定结果表明,改性后生物炭表面覆盖的颗粒被清除,微孔更清晰且孔径均有所增大; 三种改性生物炭均含有-OH官能团,其中HBC600、HBC700是新增的; HBC600、HBC700和HGBC700等电点分别为9.1、10.1和8.1.未改性生物炭BC600、BC700和GBC700吸附后引起硝氮浓度增高,而改性生物炭HBC600、HBC700和HGBC700均具有较好吸附效果.硝氮初始浓度、吸附时间及生物炭投量均影响生物炭的吸附效果,硝氮初始浓度越低、吸附时间越长、投量越大,三种改性生物炭对硝氮的去除率越高,且相同条件下HBC700对硝氮的吸附效果均最优,最大吸附量可达1.742 mg/g.在硝氮初始浓度9.0 mg/L、生物炭投量8.0 g/L、吸附时间12 h条件下,HBC700吸附去除硝氮的综合效果最佳,去除率为87.6%,且可解吸再利用.

Biochars were prepared from pomegranate peel under different conditions and then modified by hydrochloric acid. The characteristics and adsorption effects to NO3--N of the modified and raw biochars were investigated. The results of SEM, FTIR and isoelectric point showed that tiny pores of the modified biochars became clear after the particles were removed and pore diameter grew larger. Moreover, all the modified biochars had -OH group, which was the newcomer for HBC600 and HBC700. In addition, the isoelectric points of HBC600, HBC700 and HGBC700 were 9.1, 10.1 and 8.1 respectively. Unexpectedly, the raw biochars(BC600, BC700 and GBC700)could lead to the NO3--N concentration increased after adsorption, but the modified biochars(HBC600, HBC700 and HGBC700)had significant adsorptive effect on NO3--N, which was affected by the initial concentration of NO3--N, the dosage of modified biochars and the adsorption time. The removal rate of NO3--N was increased with the lowerNO3--N concentration, the larger dosage, and the longer adsorption time. Compared with others, HBC700 had the optimal adsorption ability to NO3--N and the maximum could reach 1.742 mg/g. The optimal condition for HBC700 adsorption was at 9.0 mg/L NO3--N, dosage of 8.0 g/L and adsorption time of 12 h, where the removal rate of NO3--N reached up to 87.6% and HBC700 could be reused after desorption.