Al/Zn改性竹炭去除水体中PO_4^(3-)离子及影响因素的研究

Study on Removal of PO_4^(3-) in Water by Al/Zn Modified Bamboo Charcoal and Its Influencing Factors

通过模拟实验观察Al/Zn改性竹炭对水体中PO_4^(3-)的去除效率,并考察作用时间、添加量、pH及共存离子对PO_4^(3-)去除效率的影响。当PO_4^(3-)初始质量浓度为10~50 mg/L时,去除率为10.8%~54.1%,且去除率随PO_4^(3-)初始浓度升高而提高。改性竹炭对PO_4^(3-)的吸附在45 min之内基本完成,此时对PO_4^(3-)去除效率最高。改性竹炭对PO_4^(3-)的去除效率随添加量增加而提升,但投加量由2 g/L增至4 g/L时,增幅下降,仅为0.8%~22.3%。当初始pH为2~8时,PO_4^(3-)去除效率随pH上升而提高,当初始pH为6~8时,改性竹炭对PO_4^(3-)去除率最大为62.7%~78.0%。多数离子(如SO_4^(2-)、F-、CO_3^(2-)等)的存在导致Al/Zn改性竹炭的PO_4^(3-)去除效率下降。可见Al/Zn改性竹炭能有效去除水体中PO_4^(3-),但应用时要选择合适的作用时间,添加量和pH,并注意共存离子的影响。

An simulation experiment was conducted to study the PO43- removal efficiency by AFZn modified bamboo charcoal （MBC）. Meanwhile, the effects of reaction time, charcoal dosage, pH and co-existing ions on the PO4r removal efficiency were evaluated in this study. When the initial PO4＋ concentrations were in a range of 10-50 rag/L, the removal rate was 10.8%-54.1%, and the removal rate increased with the increase of initial PO4r concentration. The PO2 removal by modified charcoal was a rapid process which was nearly completed in 45 min, when the PO4r removal rate reached a peak level. The PO~ removal rate by MBC was increased with the increase of charcoal dosage, whereas this increase effect was lower with only 0.8%~ 22.3% when it increased to 4 g/L from 2 g/L. When the initial pH was in range of 2-~8, the PO4＋ removal rate increased with the increase ofpH. Furthermore, the AI/Zn modified bamboo charcoal showed a highest PO43 removal rate with 62.7%-78.0% when the initial pH was 6~8. Most of co-existing ions （such as SO~, F, CO3~and.so on） in water led to decrease PO4r removal rate. Therefore, the AI/Zn-MBC could removal PO43- from water efficiently, however, the reaction time, dosage, pH and the co-existing ions should be comprehensively considered.