Copper chalcopyrite is a promising candidate for a photocathode material for photoelectrochemical (PEC) water splitting because of its high half-cell solar-to-hydrogen conversion efficiency (HC-STH), relatively simple and low-cost preparation process, and chemical stability. This paper reviews recent advances in copper chalcopyrite photocathodes. The PEC properties of copper chalcopyrite photoc...

Bioleaching of spent catalyst using moderate thermophilic chemolithotrophic acidophiles in growth medium without Fe source was investigated with two different pulp densities and three different size fractions. All the experiments were conducted on shake flasks at a temperature of 65 °C. The leaching yield of Ni and Al was found to be promising with very high leaching yield of 92-96% followed by...

The effects of sulfur concentration on the bioleaching of heavy metals from the sediment by indigenous sulfur-oxidizing bacteria were investigated in an air-lift reactor. Increasing the sulfur concentration from 0.5 to 5 g/l enhanced the rates of pH reduction, sulfate production and metal solubilization. A Michaelis-Menten type equation was used to explain the relationships between sulfur conce...

For recovering precious metals from waste printed circuit boards (PCBs), a novel hybrid technology including physical and biological methods was developed. It consisted of crushing, corona-electrostatic separation, and bioleaching. Bioleaching process is the focus of this paper. A novel bioreactor for bioleaching was designed. Bioleaching was carried out using Pseudomonas chlororaphis. Bioleach...

The remediation of metal-contaminated sediment was studied using the bioleaching process with a mixed culture of sulfur-oxidizing bacteria. The effects of substrate concentration (elemental sulfur) on sediment acidification, sulfur oxidation and metal solubilization from contaminated sediment during the bioleaching process were investigated with free-cell suspensions. Sulfur concentration great...

The elementary and phase analysis of discarded copper ores from Yongping of China has been performed. The experiments of extracting copper from the discarded copper ores were done with the mixed bacteria obtained through a series of enrichment, separation, domestication and combination tests. The results show that in the process of bioleaching, the pH value rises at first and drops gradually. T...

A technologically and economically feasible process called bioleaching was used for the removal of heavy metals from livestock sludge with indigenous sulfur-oxidizing bacteria in this study. The effects of sludge solids concentration on the bioleaching process were examined in a batch bioreactor. Due to the buffering capacity of sludge solids, the rates of pH reduction, ORP rise and metal solub...

Conventional leaching (extraction) methods for gold recovery from electronic waste involve the use of strong acids and pose considerable threat to the environment. The alternative use of bioleaching microbes for gold recovery is non-pollutive and relies on the secretion of a lixiviant or (bio)chemical such as cyanide for extraction of gold from electronic waste. However, widespread industrial u...

The present work deals with optimization of culture conditions and process parameters for bioleaching of spent petroleum catalyst collected from a petroleum refinery. The efficacy of Ni bioleaching from spent petroleum catalyst was determined using pure culture of Acidithiobacillus thiooxidans DSM- 11478. The culture conditions of pH, temperature and headspace volume to media volume ratio were ...