Towards a low-emission resource circulation of valuable metals from municipal solid waste incineration fly ash.

The incineration fly ash (IFA) resulting from municipal solid waste combustion is laden with heavy metals, necessitating proper treatment not only for environmental management but also to reclaim the metal values. The surge in non-traditional metals like cobalt as emerging contaminant within IFA samples further attracts to address this issue. In response, the hydrometallurgical recycling of a cobalt-bearing IFA has been studied.

Recovery of critical metals from spent Li-ion batteries: Sequential leaching, precipitation, and cobalt-nickel separation using Cyphos IL104.

This study presents a novel recycling scheme for spent Li-ion batteries that involves the leaching of lithium in hot water followed by the dissolution of all transition metals in HCl solution and their separation using the ionic liquid Cyphos IL104. The parametric studies revealed that >84 % Li was dissolved while the cathode material was leached at 90 °C for 2 h. Approximately 98 % Li from the non-acidic solution was directly precipitated as LiCO at a Li:CO ratio of 1:1.

Biotechnological recycling of hazardous waste PCBs using Sulfobacillus thermosulfidooxidans through pretreatment of toxicant metals: Process optimization and kinetic studies.

The present study dealt with the restricted microbial tolerance for lead and tin during bioleaching of waste printed circuit boards (WPCBs) and lower extraction yields of valuable metals. Pretreatment of WPCBs in 4.0 mol/L HNO at 90 °C for 180 min duration prominently dissolved the toxicant metals before the microbial mobilization of valuable metals.

O-enriched microbial activity with pH-sensitive solvo-chemical and electro-chlorination strategy to reclaim critical metals from the hazardous waste printed circuit boards.

An innovative process integration for the sustainable recovery of critical metals from waste printed circuit boards (WPCBs) is demonstrated. In the acid pre-treatment of WPCBs, > 95% of highly toxic metals lead and tin could dissolve after 240 min of contact in 4.0 mol L HNO.

Disinfection technology and strategies for COVID-19 hospital and bio-medical waste management.

The isolation wards, institutional quarantine centers, and home quarantine are generating a huge amount of bio-medical waste (BMW) worldwide since the outbreak of novel coronavirus disease-2019 (COVID-19). The personal protective equipment, testing kits, surgical facemasks, and nitrile gloves are the major contributors to waste volume. Discharge of a new category of BMW (COVID-waste) is of great global concern to public health and environmental sustainability if handled inappropriately.