Rice husk biochar removes fluoride from groundwater, prevents drinking water contamination, new study shows

Rice husk biochar removes fluoride from groundwater, prevents drinking water contamination, new study shows

Subject :Environment

Section: Pollution

Why flouride contamination is dangerous?

• Prolonged fluoride consumption in higher concentrations in drinking water can cause dental fluorosis, skeletal fluorosis, kidney diseases, arthritis.
• Skeletal fluorosis is somewhat more difficult to identify unless significant deformation occurs and typically requires radiographic testing. Thus, it may not be as prominent as dental fluorosis. For 4,157 habitats over 98 blocks in 11 districts of Bihar, the level of fluoride in the groundwater is alarmingly high.

How contamination happens?

• Groundwater, extracted with tube wells and hand pumps, is the most important source for drinking and cooking in rural India. Blind extraction encourages groundwater contamination with several pollutants, mainly geogenically.

Where this contamination is prominent?

• In Bihar, for instance, groundwater in the rural areas of 31 of the 38 districts have high concentrations of arsenic, fluoride and iron, constituting a serious health risk. Fluoride, one of the pollutants in groundwater, is primarily caused by geological processes but is also contributed through anthropogenic activities across India.

Why rice husk biochar?

Crop residue management is challenging in Bihar and across India, as farmers willingly or unwillingly burn the residue on farms. Biochar’s can help in this.

How it happens ?

What is a Biochar?

• Biochar is a high-carbon, fine-grained residue that is currently produced through modern pyrolysis processes (direct thermal decomposition of biomass in the absence of oxygen and preventing combustion).
• It produces a mixture of solids (the biochar proper), liquid (bio-oil), and gas (syngas) products.
• Biochar may increase soil fertility of acidic soils (low pH soils), increase agricultural productivity, and provide protection against some foliar and soil-borne diseases.

Benefits of biochar:

• Biochar has other uses too — apart from safekeeping carbon, biochar has several uses in agriculture.
• Agricultural leftovers such as rice husk are a major source of biomass, and the biochar it forms has significant mineral content. Adding it to soil enriches plant nutrients.
• The porous nature of biochar makes it suitable for remediation — the adsorption of toxic substances in polluted soils – thus reducing the potency of contaminants in the soil.