Preparation of macroporous ion-exchange resin organic amine composite material by using waste plastics and its application in CO2 capture

Two new types of solid adsorption material (macroporous cation exchange resin (MCER) and macroporous ion-exchange resin organic amine composite material (MCER-DEA)) were prepared from waste television plastics outer shell (WTPS) and used to capture CO₂ in flue gas from coal-fired power plants. The results showed that the CO₂ adsorption capacity of MCER-DEA was 2.87 mmol/g, while MCER was 1.87 mmol/g. The preparation mechanism and action mechanism of MCER and MCER-DEA was studied by Fourier transform infrared and quantum chemical calculations. The results showed that the electrophilic substitution occurs in between an H atom of meta position on the benzene ring and H₂SO₄. The electron energy of MCER-DEA was calculated to be 1.14 ev, indicating these MCERs formed acid-base coordination with diethanolamine (DEA). Besides, the electron energy of between MCER and CO₂ was 0.27 ev, and the interaction force was dominated by hydrogen bonds. The electron energy of the MCER-DEA and CO₂ was 3.02 ev, and the interaction force was mainly controlled by coordination bonds. It indicated that MCER and CO₂ were primarily based on physical adsorption, while MCER-DEA and CO₂ were mainly based on chemisorption adsorption. Adsorption kinetics studies showed that internal diffusion was a rate-controlling step.

Fungal biotechnology for urban mining of metals from waste printed circuit boards: A review

Rapid surge in electronic waste (e-waste) and its unscientific handling has an adverse impact on humans and the environment. Waste printed circuit board (WPCB), an integrated component of e-waste, has a high metallic content that includes both toxic and precious metals. Therefore, metal recovery is essential not just to avoid environmental degradation but also for economic growth. The current literature analysis focuses on one such eco-friendly approach, known as fungal biotechnology, for extracting metals from WPCBs. Among diverse bioleaching agents, fungi have shown promising metal extraction efficiency (Al: 65-96%; Co: 45-90%; Cu: 34-100%; Ni: 8-95%; Mn: 70-95%; Pb: 27-95%; Zn: 54-99%) and the ability to work in a wide pH range. However, in terms of metal recovery from WPCBs, fungal bioleaching has been less explored. This review, thus, assesses the fungal biotechnology for metal extraction from WPCBs and discusses the associated mechanism and kinetics involved. Different process parameters affecting the fungal bioleaching have also been discussed briefly. The review highlights that, while this process has enough potential, some associated drawbacks hinder its practical applicability on an industrial scale. Lastly, some suggestions for scaling up and reducing the cost of the process have been made, which need to be addressed.

Preparation of anion exchange resin by recycling of waste printed circuit boards

The treatment of the non-metal components of waste printed circuit boards (WPCBs) is very difficult because they are inflexible and insoluble, and thus a new method to convert them into anion exchange resin was studied.