Can biochar be the holistic solution? Exploring the potential applications of biochar utilisation in pollution management in Zimbabwe.
Zimbabwe is in a quandary state as it is plagued by an environmental crisis encapsulating unprecedented rates of soil degradation, land, and water and air pollution. Biochar, a carbonized, dense, and solid by-product of bioenergy product…
Zimbabwe is in a quandary state as it is plagued by an environmental crisis encapsulating unprecedented rates of soil degradation, land, and water and air pollution.
Biochar, a carbonized, dense, and solid by-product of bioenergy production through degasification of organic material subjected to low oxygen conditions, has of late gathered research as a potential remedy to mitigate all forms of pollution. Consequently, this paper seeks to critically evaluate the potential opportunities and challenges associated with the use of biochar as a holistic technique in pollution control in Zimbabwe. In a nutshell, Zimbabwe generates roughly about 9.9 Mt yr-1 of biochar feedstock per annum, 98% of which is in the form of manure (8.7 Mt yr-1) and firewood (1.0 Mt yr-1).
Biochar has several possible applications in the remediation of polluted soils and water, re-vegetation, and restoration of degraded soils. Correspondingly, Beesley et al (2010) in their study exploring pollutant movement in soils have demonstrated the efficiency of biochar as an adsorbent. This paper argues that biochar presents a great opportunity for pollution remediation owing to its ability to diminish the mobility and toxicity of substances such as heavy metals, and toxic organic and inorganic pollutants.
Moreover, biochar has the potential to remove polyaromatic hydrocarbons, and organic pesticides such as Atrazine and diminish the bioavailability of heavy metals. Furthermore, biochar possesses the potential to play a key role in the remediation and re-vegetation of polluted abandoned mine sites such as mine tailings. This is mainly significant in Zimbabwe given the predominance of both formal and informal mining activities which results in considerate environmental pollution
Moreover, this paper contends that biochar possesses the potential of being used as an alternate energy source, thereby alleviating air pollution associated with the increased use of fossil fuels in Zimbabwe. In contrast to fossil fuels, Laird (2008) assert that energy from the products of pyrolysis is carbon neutral rendering them perfect alternative energy sources for the future.
Furthermore, whereas the combustion of fossil fuels emits dioxins, no trial evidence has established/ confirmed emissions of dioxins from biochar. Additionally, the use of biochar offers opportunities for more effective and efficient energy production and also broadens the alternatives for the types of biomass that might be utilized in energy generation. Moreover, biochar provides clean heat, which is required to advance cooking technology with reduced indoor pollution.
Zimbabwe predominantly thrives in agriculture, particularly crop and animal production. Smith et al (2006) asserts that these agricultural systems significantly contribute to climate change, being responsible for about 5.1 to 6.1 Gt CO2 eq yr-1 (10-12%) of the total yearly worldwide anthropogenic emissions. In the same vein, this paper contends that the adoption of the biochar utilization commercial and smallholder agriculture systems in Zimbabwe will be in line with the international drive to diminish greenhouse gas emissions and sequester soil carbon.
Moreover, biochar can go a long way in promoting a change from tillage to no-till agricultural systems through conservation agriculture. To validate this claim, a study conducted on tropical soils by Rondon et al (2006) found that biochar application diminished the emission of methane on grassland and soyabean crops compared to the control.
The incorporation of biochar in the treatment of wastewater treatment in decentralized systems offers an attractive alternative for enhancing sanitation in rural communities and institutes such as hospitals. Gwenzi et al (2015) postulate that the combination of inexpensive drinking water chlorination systems and biochar can provide an attractive option as a cheap adsorbent in wastewater treatment. Based on its ability to adsorb both anionic and cationic compounds, biochar can be used in industrial effluent and urban stormwater treatment prior to discharge into the environment.
While biochar possesses the immense potential to be utilized in pollution control in Zimbabwe, there is a need to deal with several obstacles and limitations such as financial, legal, technical, policy, and socio-economic barriers. This paper claim that the government of Zimbabwe may be ignorant of biochar and subsequently lack a strong policy framework on biochar technologies. Moreover, the lack of government and public investment in biochar is stark in Zimbabwe when compared to first-world countries where large-scale biochar production and utilization is in operation.
The incorporation of biochar and its co-products in Zimbabwe entails the development of practical skills at both personal and institutional levels. Presently, there is little to no research with regard to biochar at nationwide research institutions and universities in Zimbabwe. Additionally, this paper argues that to date the labour, capital outlay, and financial requirements needed to establish and operate a biochar production plant in Zimbabwe are unknown. Consequently, this paper concludes that there is a need for rudimentary and fundamental research to demonstrate the benefits of biochar utilization in pollution control and the development of legislative and regulatory frameworks for its production and adoption.