粉煤灰对水溶液中磷的吸附性能及机理  

Performance and mechanism of phosphorus adsorption in aqueous solution with fly ash

作　　者：周光红[1,2] 项学敏[1,2] 李厚芬[1,2] 周集体[1,2] 

机构地区：[1]大连理工大学环境学院,大连116024 [2]大连理工大学工业生态与环境工程教育部重点实验室,大连116024

出　　处：《环境工程学报》2012年第8期2600-2606,共7页Chinese Journal of Environmental Engineering

基　　金：国家水体污染控制与治理科技重大专项(2009ZX07208-002)

摘　　要：以粉煤灰为吸附剂去除溶液中的磷,考察了其吸附除P动力学特征、热力学特征以及溶液初始pH和粉煤灰投加量对吸附除P效果的影响,并对其吸附除P机理做了初步探讨。结果表明,在给定实验条件下,粉煤灰对P具有较好的去除效果,随着初始P浓度从10 mg/L升高到80 mg/L,平衡吸附量为0.46～2.44 mg P/g粉煤灰,吸附效率从92.2%降低至61.1%;对不同浓度的含P溶液,粉煤灰最适用量为0.6～1.5 g粉煤灰/mg P;相同反应条件下,当温度由25℃升高到45℃时,P初始吸附速率提高了3倍;粉煤灰对P的吸附过程能够较好地拟合Langmuir、Freundlich及D-R吸附等温模型,相关系数均在0.98以上。通过对吸附饱和的粉煤灰进行解析实验发现,初始P浓度较低(<50 mg/L)时,以化学吸附为主,而在初始P浓度较高(>80 mg/L)时,则以物理吸附为主。Fly ash was used as adsorbent to remove P from solution, phosphorus adsorption kinetics, ther- modynamics as well as the influences of pH and adsorbent dosage on P removal effects were all investigated, the mechanism of P adsorption onto fly ash was preliminarily studied. Results indicated that P could be removed by fly ash efficiently under the given conditions. With the concentration of P increased from 10 mg/L to 80 mg/L, the equihbrium adsorption capacity of fly ash increased from 0.46 mg P/g fly ash to 2.44 mg P/g fly ash, while the removal efficiency decreased from 92.2% to 61.1%. The optimal dosage of fly ash was 0.6 - 1.5 g fly ash/ mg P, even when P concentrations were different; under the same conditions, the initial sorption rate was im- proved by 3 times when the temperature increased from 25C to 45C. Langmuir, Freundlich and D-R isotherms were a[l fit to the adsorption characteristics of fly ash （R2 〉 O. 98 ） The results obtained from P desorption indi- cated that with lower P concentration（ 〈 50 mg/L） , the adsorption was mainly chemical reaction, whereas, with higher P concentration（ 〉80 rag/L） , physical adsorption was the main process

关 键 词：粉煤灰 除磷机理 物理吸附 化学吸附 

分 类 号：X703[环境科学与工程—环境工程]