摘要
利用生物炭材料的吸附作用回收污水中的磷,作为磷肥应用到土壤进行农业生产是一种简单有效、成本低廉的措施,成为解决环境污染和磷资源紧缺问题的一种潜在方案。该研究采用单因素结合响应面方法优化赤铁矿(H)改性核桃壳生物炭(BC)的制备工艺。通过模型拟合分析了改性生物炭(H-BC)对水中磷(P)的吸附特性,并测试表征探讨其吸附机理。最后,将饱和吸附磷后的改性生物炭(H-BC-P)应用到土壤,采用盆栽试验分析其作为磷肥的效果和潜力。结果表明:核桃壳/赤铁矿质量比为1:1,在850℃下热解45 min制得的改性生物炭对磷的去除率达到98.42%,饱和吸附量为15.59 mg/g。H-BC吸附P的过程更符合准二级动力学模型和Freundlich模型,表明该过程是多分子层吸附,化学吸附是限制吸附速率的主要步骤。酸性条件有利于H-BC对P的吸附,从成本角度考虑,H-BC的最佳用量为2.5 g/L。H-BC-P可以改良酸性土壤pH,增加土壤全磷和Olsen-P含量。黄棕壤和红壤中生菜的生物量均有明显增加。研究表明赤铁矿改性生物炭是一种环境友好的磷吸附剂,且吸附磷后的残渣可以作为磷肥应用到土壤。
Biochar can be utilized as an adsorption material to recover phosphorus(P)from wastewater,and then applied as the phosphorus fertilizer in soil for agricultural production.The simple,effective,and cost-effective way can be expected as the potential solution to environmental pollution and phosphorus resource scarcity.However,single biochar(BC)has relatively limited adsorption capacity for anions,due to its negative charge.Additionally,the functional groups can be lost in the processes of BC production during high-temperature pyrolysis.Therefore,more research tends to focus on modified BC and composite materials,in terms of their adsorption performance.Iron oxides,especially natural iron minerals,are widely used for P recovery,due to their abundant reserves,low cost,and fast reactivity.Loading hematite(H)onto the inner and outer surfaces of larger-sized BC can enhance the selective adsorption of BC for PO43−.Significant adsorbent loss can also be avoided in recovery when using H alone.In this study,the preparation process of modified walnut shell BC with H was optimized using a single-factor combined response surface method(RSM).Model fitting was used to analyze the adsorption characteristics of modified biochar(H-BC)for P in water.Finally,the modified biochar saturated with adsorbed phosphorus(H-BC-P)was applied to the soil in pot experiments.The performance of adsorption was verified to evaluate the potential of the P fertilizer.The results showed that the modified biochar produced by pyrolyzing at 850°C for 45 minutes achieved a P removal rate of 98.42%and a saturated adsorption capacity of 15.59 mg/g at a walnut shell/hematite mass ratio of 1:1.The adsorption process of P by H-BC was better described by the pseudo-second-order kinetics and the Freundlich model,indicating multilayer adsorption,with the rate-limiting step of chemical adsorption.Acidic conditions favored the adsorption of P by H-BC.The optimal dosage of H-BC was 2.5 g/L from a cost perspective,resulting in a P removal rate of 95.31%.BET test re
作者
马啸
熊巧
周香君
吴宏涛
严素定
梅骏伦
MA Xiao;XIONG Qiao;ZHOU Xiangjun;WU Hongtao;YAN Suding;MEI Junlun(College of Urban and Environmental Sciences,Hubei Normal University,Huangshi 435002,China;Resource-exhausted Cities Transformation and Development Research Centre,Hubei Normal University,Huangshi 435002,China)
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2023年第22期216-225,共10页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家自然科学基金项目(41907124)
湖北省自然科学基金联合基金项目(2022CFD046)
湖北省高等教育中青年优秀创新团队项目(T2021011)
资源枯竭城市转型与发展研究中心开放基金项目(KF2023D1)。
关键词
生物炭
改性
赤铁矿
磷回收
土壤
biochar
modification
hematite
phosphate reclamation
soil
