Institute of Resources, Ecosystem and Environment of Agriculture, Nanjing Agricultural University, 1 Weigang, Nanjing, 210095, China.
Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, 1 Weigang, Nanjing, 210095, China.
Environ Sci Pollut Res Int. 2023 Dec;30(58):122364-122380. doi: 10.1007/s11356-023-30777-1. Epub 2023 Nov 15.
Massive amount of food waste has been generated annually, posing a threat to ecological sustainability and the social economy due to current disposal methods. Urgent action is needed worldwide to convert the traditional pathway for treating food waste into a sustainable bioeconomy, as this will significantly benefit food chain management. This study explores the use of pyrolysis to produce different types of food waste biochars and investigates their adsorption capabilities for removing Cd and Pb in aqueous solution. The results indicated that co-pyrolysis biochar from fresh food waste and rice husk (FWRB) exhibited superior adsorption performance for Cd (61.84 mg·g) and Pb (245.52 mg·g), respectively. Pseudo-second-order kinetics (0.74 ≤ R ≤ 0.98) and Langmuir isotherms (0.87 ≤ R ≤ 0.98) indicated that the immobilized Cd and Pb on biochars were mainly attributed to the chemisorption, including precipitation with minerals (e.g., carbonates, silicates, and phosphate), complexation with functional groups (-OH), cation exchange (-COO), and coordination with π-electrons. Furthermore, FWRB demonstrated reduced EC and Na content in comparison to food waste digestate biochar (FWDB) and food waste digestate co-pyrolysis with sawdust biochar (FWSB), with levels of Cd and Pb falling below China's current guideline thresholds. These findings suggested that co-pyrolysis of fresh food waste with rice husk could be applicable to the recycling of food waste into biochar products for heavy metal stabilization in contaminated water and soils.
每年都会产生大量的食物垃圾，由于目前的处理方法，对生态可持续性和社会经济构成了威胁。全球范围内需要采取紧急行动，将传统的处理食物垃圾的方法转变为可持续的生物经济，因为这将对食物链管理有重大意义。本研究探索了利用热解作用来生产不同类型的食物垃圾生物炭，并研究了它们对去除水溶液中 Cd 和 Pb 的吸附能力。结果表明，来自新鲜食物垃圾和稻壳的共热解生物炭（FWRB）对 Cd（61.84mg·g）和 Pb（245.52mg·g）的吸附性能分别更为优越。准二级动力学（0.74 ≤ R ≤ 0.98）和 Langmuir 等温线（0.87 ≤ R ≤ 0.98）表明，生物炭上固定的 Cd 和 Pb 主要归因于化学吸附，包括与矿物质（如碳酸盐、硅酸盐和磷酸盐）的沉淀、与官能团（-OH）的络合、与阳离子的交换（-COO）以及与π-电子的配位。此外，与食物垃圾消化物生物炭（FWDB）和食物垃圾消化物与木屑共热解生物炭（FWSB）相比，FWRB 的 EC 和 Na 含量降低，Cd 和 Pb 的含量低于中国现行的指导值标准。这些发现表明，将新鲜食物垃圾与稻壳共热解可以应用于将食物垃圾回收为生物炭产品，以稳定污染水和土壤中的重金属。
