镧改性虾壳低温热解制备的生物炭对池塘养殖废水磷吸附的研究OACSTPCD
PREPARATION OF BIOCHAR BY LOW TEMPERATURE PYROLYSIS OF LANTHANUM MODIFIED SHRIMP SHELLS FOR EFFICIENT PHOSPHORUS ADSORPTION
为提高生物炭对磷的去除效果和将厨余废弃物的资源化利用,文章以废弃虾壳为原料,用NaOH将LaCl3以La(OH)3沉淀形式附着在虾壳表面,进行热解得镧改性生物炭(CSLa).采用XRF、SEM、BET、FTIR和XRD对改性前后的生物炭表征分析.采用吸附等温线模型和吸附动力学模型拟合生物炭的吸磷特征.研究了改性剂用量、初始pH、共存干扰离子对生物炭吸附磷的影响.结果表明镧化合物负载在生物炭表面,对磷吸附能力明显提高,最大理论吸附量为160.51 mg/g,与CS400磷最大吸附量(100.60 mg/g)相比约提高60％.在低浓度或高浓度磷溶液条件下,CSLa对磷吸附量和去除率均高于CS400,在实际水产养殖废水中更实用.吸附过程主要受化学吸附、颗粒内扩散控制.有关机理分析的结论表明表面沉淀作用、静电吸引、配体交换和内层络合作用是CSLa吸附磷的主要机理.CSLa更适合在弱酸性环境中除磷,不过在碱性环境条件下其吸附量也比较高.HCO3-和CO2-3对CSLa磷吸附有一定的抑制作用.研究以低温400℃为热解温度制备镧改性生物炭,不仅提升了生物炭对磷的吸附量和去除率,而且消耗热能较少,更有利于实际应用.
In order to improve the phosphorus removal effect of biochar and resource utilization of food waste,we ob-tained lanthanum-modified biochar(CSLa)by using waste shrimp shells as raw material and attaching LaCl3 to the sur-face of shrimp shells in the form of La(OH)3 precipitation with NaOH by pyrolysis.The modified and unmodified biochar samples were characterized and analyzed by XRF,SEM,BET,FTIR and XRD.The adsorption kinetic and ad-sorption isotherm models were used to fit the phosphorus absorption characteristics of the biochar.The effects of modi-fier dosage,initial pH and coexisting interfering ions on phosphorus adsorption by biochar were investigated.The re-sults showed that lanthanum modified shrimp shell biochar(CSLa)had abundant oxygen-containing functional groups on its surface.CSLa consisted mainly of La2O3,and its pore size distribution was dominated by mesoporous pores.The phosphorus adsorption process was better fitted with Langmuir isotherm,indicating the adsorption of phosphorus on CSLa was monolayer adsorption.The adsorption of phosphorus on CSLa was better described by quasi-secondary kine-tics,indicating the phosphorus adsorption process by CSLa was chemisorption.The maximum theoretical adsorption capacity of CSLa was found to be 160.51 mg/g,achieved after 12h of adsorption.The adsorption and removal rates of phosphorus by CSLa were higher than those by CS400 at low or high phosphorus concentrations,which was more prac-tical in real aquaculture tailwater.The adsorption rate of phosphorus on CSLa was mainly controlled by chemical ad-sorption and intraparticle diffusion.The mechanism analysis indicated that surface precipitation,electrostatic attraction,ligand exchange and internal complexation were the main mechanisms of phosphorus adsorption by CSLa.CSLa demonstrated better phosphorus removal performance under weakly acidic conditions,while the adsorption capacity was relatively high under alkaline environmental conditions.The interfering ions Cl-,NO3-,NO2-and SO42-had no ef-fect on CSLa phosphorus adsorption,while HCO3 and CO3-had some inhibitory effect on CS400 phosphorus adsorp-tion.In this study,lanthanum-modified biochar was prepared at a low temperature of 400 ℃ as the pyrolysis tempera-ture,which not only enhanced the adsorption and removal rate of phosphorus by biochar,but also consumed less thermal energy,which was more beneficial to practical applications.
韩孟飞;徐栋;武俊梅;曹涛涛;白国梁;陈迪松;杨夯;吴振斌
中国科学院水生生物研究所淡水生态与生物技术国家重点实验室,武汉 430072||中国科学院大学,北京 100049中国科学院水生生物研究所淡水生态与生物技术国家重点实验室,武汉 430072||武汉市生态环境科技中心,武汉 430015中国科学院水生生物研究所淡水生态与生物技术国家重点实验室,武汉 430072武汉理工大学,武汉 430063
环境科学
虾壳生物炭磷酸盐吸附镧改性
Shrimp shell biocharPhosphate adsorptionLanthanum modification
《水生生物学报》 2024 (002)
253-263 / 11
国家自然科学基金区域创新发展联合基金(U20A2010);江汉湖群清洁水产水质净化的生物——生态学基础和保障策略资助[Supported by the National Natural Science Foundation of China Regional Innovation and Development Joint Fund(U20A2010):Study on the Basis of Biology and Ecology on Water Purification During the Clean Aquaculture of Jianghan Lake group]
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