| 张国胜,程红艳,张海波,苏龙,何小芳,田鑫,宁瑞艳.双孢菇菌糠生物炭吸附Pb2+机制及其环境应用潜力[J].农业环境科学学报,2021,40(3):659-667. |
| 双孢菇菌糠生物炭吸附Pb2+机制及其环境应用潜力 |
| Adsorption mechanism of Pb2+ in water by biochar derived from spent Agaricus bisporus substrate and its environmental application potential |
| 投稿时间：2020-08-15 |
| DOI：10.11654/jaes.2020-0961 |
| 中文关键词: 双孢菇菌糠 生物炭 铅污染 热解温度 吸附机理 应用潜力 |
| 英文关键词: Agaricus bisporus substrate biochar lead pollution pyrolysis temperature adsorption mechanism application potential |
| 基金项目:山西省自然科学基金项目（201901D111216）；山西省煤基重大科技攻关项目（FT2014-03）；山西省重点研发计划项目（201903D211012-05） |
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| 中文摘要: |
| 为了有效去除水体中的重金属Pb2+，开发利用菌糠生物炭吸附剂，以双孢菇菌糠（MS）为原料，在350、550、750℃下限氧热解制备生物炭（MS350、MS550、MS750），并利用FTIR、XRD等技术对吸附前后的生物炭样品进行表征；通过批量吸附、定性和定量分析以及萃取实验，研究菌糠生物炭对Pb2+的吸附特性、机理及吸附后样品的稳定性能。结果表明：随着热解温度的升高，样品的产率降低，pH值升高，芳香性增强。准二级动力学方程和Freundlich模型能够较好地符合MS350、MS550的吸附过程，而MS750以准二级动力学和Langmuir模型较好符合。相较于MS350和MS550，MS750吸附性能最好，经Langmuir模型拟合，MS750的最大吸附量为266.23 mg·g-1。溶液pH值影响生物炭的吸附性能，在pH值2.0~7.0的范围内，吸附量随溶液pH值升高而增加。机理分析表明：吸附机理包括矿物沉淀、阳离子交换、含氧官能团络合以及π电子配位；其中，矿物沉淀（CO32-、SO42-）是主要的吸附机制，其贡献率随热解温度升高而增加。萃取实验表明：经吸附后，3种生物炭上的Pb2+均以酸溶态铅和非生物利用态铅为主，说明吸附后的铅具有较好稳定性能，两种形态的铅占总吸附量的大小顺序为：MS750（98.65%）>MS550（95.91%）>MS350（86.51%）。综合分析表明，MS750较其他温度生物炭不仅吸附性能更好，而且吸附后稳定性更强，故在环境应用上具有更大的潜力。 |
| 英文摘要: |
| To utilize the biochars from spent mushroom substrate for adsorbing Pb2+ in aqueous solutions effectively, they were prepared using spent Agaricus bisporus substrate(MS) as raw materials by limited oxygen pyrolysis under 350, 550℃, and 750℃(MS350, MS550, and MS750). The original and lead-loaded biochars were characterized using XRD and FTIR. The adsorption characteristics and removal mechanisms of Pb2+ on biochars were investigated by batch adsorption and sequential metal extraction tests. Results indicated that the biochar yield decreased while the pH and aromaticity increased with an increase in pyrolysis temperature. The adsorption kinetics of biochars were well-fit to the pseudo-second order model. The isothermal adsorption of MS350 and MS550 was better described using the Freundlich isotherm model, whereas MS750 was better described using the Langmuir model. Among the biochars, MS750 was the most effective adsorption biochar, and the maximum adsorption capacity reached 266.23 mg·g-1. The solution pH affected the adsorption performance of biochars, and the adsorption capacity increased with an increase in solution pH in the range of 2.0~7.0. The possible mechanisms of Pb2+ adsorption on the biochars included precipitation with minerals, ion exchange, complexation with surface oxygen-containing functional groups, and coordination with π electrons. Mineral precipitation(CO32-, SO42-) was the primary adsorption process, and its contribution rate increased with the increase of pyrolysis temperature. The results of sequential lead extractions showed that the Pb of biochars was mainly acid-soluble and non-available fractions, indicating that the majority of Pb immobilized by the biochars was stable. The order of total acid-soluble and non-available fractions of Pb in the total adsorption capacity was as follows:MS750(98.65%) > MS550 (95.91%) > MS350(86.51%). MS750 had a higher pH and adsorption capacity of Pb2+ and better stability after Pb2+ adsorption than those of other biochars. Therefore, it has great potential in environmental applications. |
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