Biomining

Source-This post on Biomining is based on the article “Biomining at landfills in Ghazipur, Bhalswa set to miss latest deadline” published in “Hindustan times” on 18th March 2024.

Why in the News?

Delhi’s biomining project to clear landfill sites is likely to miss the latest deadline of 2024.

About Biomining 

1. About: Biomining is the scientific process of excavation, treatment, segregation and gainful utilisation of aged municipal solid waste lying in dumpsites typically referred to as legacy waste.

2. It comprises 4 steps: It involves excavation of legacy waste, stabilizing the waste using bioremediation, segregation of excavated waste and then sustainable management and its safe disposal.

3. Methods of Biomining: The methods of biomining include Bioleaching, Bio-oxidation, Dump leaching, and Agitated leaching.

a) Bioleaching: This method involves dumping low-grade ore into a heap called a leach pile and then soaking it with a weak sulphuric acid wash.

The acid reacts with the ore’s sulfide matrix and encourages the growth of bacterial strain which starts to degrade ore and releases minerals or metals in fluid form.

b) Bio-oxidation method is widely used for the extraction of gold from ores. The ore is exposed to bacterial oxidation which degrades the insoluble pyrite and arsenic components.

c) Dump leaching is an industrial process to extract precious metals and copper from ores.

d) Agitation leaching method is chemical process used to extract mineral from soil. 

4) Biomining in Solid Waste Management: a) Biomining is used to clear oil spills in the sea and pollution from the soil, groundwater, surface water, and air.

b) It is used to degrade environmental contaminants into less toxic or non-toxic forms.

c) It can also be used for wastewater treatment, industrial waste, hydrocarbon contamination, storage tanks and pipes, landfills, pesticides, herbicides, and the treatment of agricultural chemical waste.

5. Benefits: a) Biomining allows to recycle resources by extracting useful components from the waste such as metal, as compost in fertilizer, etc.

b) It is eco-friendly, environmentally sustainable, and after using this technique, it can be used as the contaminated land for other purposes.

6. Disadvantages: a) Biomining is restricted to only biodegradable compounds and takes time to show results.

b) There is risk of leakage and treatment of the acidic, metal-rich solution created by the microbes.

c) It can be managed if done in controlled conditions by following protocols.

Read more: Bioremediation

UPSC Syllabus: Environment