Heavy metal bioleaching and sludge stabilization in a single-stage reactor using indigenous acidophilic heterotrophs
| Autor: | Akanksha Mehrotra, Trichur Ramaswamy Sreekrishnan |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Acidithiobacillus Iron 030106 microbiology Heterotroph 010501 environmental sciences Biology 01 natural sciences Metal 03 medical and health sciences Bioreactors Metals Heavy Bioleaching Environmental Chemistry Waste Management and Disposal Pcr dgge 0105 earth and related environmental sciences Water Science and Technology Sewage Waste management Single stage Heavy metals General Medicine Hydrogen-Ion Concentration Pulp and paper industry Metal leaching visual_art visual_art.visual_art_medium Sulfur Mesophile |
| Zdroj: | Environmental Technology. 38:2709-2724 |
| ISSN: | 1479-487X 0959-3330 |
| DOI: | 10.1080/09593330.2016.1275821 |
| Popis: | Simultaneous sludge digestion and metal leaching (SSDML) have been reported at mesophilic temperature. It is generally perceived that while sludge stabilization is effected by heterotrophs at neutral pH, metal bioleaching is done by acidophilic autotrophs. However, little information is available on the microbial communities involved in the process. This study carried out SSDML in a single-stage reactor using sludge indigenous microorganisms and looked at the bacterial communities responsible for the process. Volatile suspended solids were reduced by more than 40%. The concentration of zinc, copper, chromium, cadmium and nickel decreased by more than 45% in the dry sludge. Acidophilic species of Alicyclobacillus genus were the dominant heterotrophs. A few heterotrophic bacteria were detected which can oxidize iron (Alicyclobacillus ferrooxydans, Alicyclobacillus ferripilum and Ferrimicrobium acidiphilum). Acidithiobacillus ferrooxidans (autotroph) was responsible for the oxidation of both iron and sulfur which lead to a change in the pH from neutral to acidic. The presence of acidophilic heterotrophs, which can oxidize either iron or sulfur, enhanced the efficiency of SSDML process with respect to sludge stabilization and metal leaching. This study shows that it is possible to carry out the SSDML in a single-stage reactor with indigenous microorganisms. |
| Databáze: | OpenAIRE |
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