by: Institute of Urban Environment,Chinese Academy of Sciences

At present, the situation of sewage treatment and sludge disposal is severe. On the one hand, sewage and sludge contain a large amount of harmful substances such as heavy metals, and improper treatment will cause environmental pollution; on the other hand, sewage and sludge contain a lot of resources, which can be recycled. Potential, the recovery of rare earth elements and other resources from sludge has gradually received attention. Most of the reported methods for recovering and enriching rare earth elements from sewage and sludge have problems such as high cost and low recovery rate. Exploring and optimizing the recovery process can provide technical support for environmental pollution restoration and resource recovery.

In recent years, the Environmental Biotechnology Group of the Institute of Urban Environment of the Chinese Academy of Sciences has devoted itself to research on the control technology of rare earth elements in sewage treatment systems. In order to achieve efficient recovery of rare earth elements, this research prepared porous β-cyclodextrin polymer (P-CDP) and its magnetic composite material (P-CDP@Fe₃O₄). Both P-CDP and P-CDP@Fe₃O₄ can quickly recover Nd, Y, Eu, and Gd and other rare earth elements, and can reach adsorption equilibrium within 10 minutes. Fitting the Langmuir isothermal model shows that the maximum adsorption capacity of the material is 7.76~9.59mg/g (25℃); P-CDP and P-CDP@Fe₃O₄ are selective for the recovery of rare earth elements, and the recovery rate will not be affected by alkali metal, The recovery rate is between 62% and 100% due to the influence of competing ions such as alkaline earth metals and transition metals; P-CDP and P-P-CDP@Fe₃O₄ can be regenerated under weak acid conditions and can be reused more than five times. Compared with P-CDP, P-CDP@Fe₃O₄ has low clogging properties and low operating pressure, and can be separated from the system by an external magnetic field quickly and with low energy consumption, which is more conducive to the recovery and application of rare earth elements.

Relevant research results were published in Water Research on the topic of Selective and fast recovery of rare earth elements from industrial wastewater by porous β-cyclodextrin and magnetic β-cyclodextrin polymers. Francois Nkinahamira, a doctoral student from Rwanda, is the first author of the paper, and Sun Qian, a researcher at the Institute of Urban Environment, is the corresponding author of the paper. The research work was funded by the Fujian Institute of Material Structure Research of the Chinese Academy of Sciences-Urban Environment Institute Integration Development Fund, the Chinese Academy of Sciences-Third World Academy of Sciences Dean Scholarship and the Youth Innovation Promotion Association of the Chinese Academy of Sciences.

Paper links: https://linkinghub.elsevier.com/retrieve/pii/S0043135420303948

P-CDP@Fe₃O₄ And its application in recovering rare earth from waste water

Source: http://www.cas.cn/syky/202009/t20200928_4761693.shtml

Disclaimer: This article is translated by cpolymer. The translation is for reference only. All contents are subject to the original text.