Applications of Biochar

Biochar is a carbon-rich, fine-grained residue which can be produced either by ancient techniques (such as covering burning biomass with soil and allowing it to smoulder) or state-of-the-art modern biomass pyrolysis processes. Combustion and decomposition of woody biomass and agricultural residues results in the emission of a large amount of carbon dioxide. Biochar can store this CO2 in the soil leading to reduction in GHGs emission and enhancement of soil fertility. Biochar holds the promise to tackle chronic human development issues like hunger and food insecurity, low agricultural productivity and soil depletion, deforestation and biodiversity loss, energy poverty, water pollution, air pollution and climate change. Let us have a close look at some of the most promising applications of biochar.

 

Use of biochar in animal farming

At present approx. 90% of the biochar used in Europe goes into animal farming. Different to its application to fields, a farmer will notice its effects within a few days. Whether used in feeding, litter or in slurry treatment, a farmer will quickly notice less smell. Used as a feed supplement, the incidence of diarrhoea rapidly decreases, feed intake is improved, allergies disappear, and the animals become calmer.

In Germany, researchers conducted a controlled experiment in a dairy that was experiencing a number of common health problems: reduced performance, movement disorder, fertility disorders, inflammation of the urinary bladder, viscous salivas, and diarrhoea. Animals were fed different combinations of charcoal, sauerkraut juice or humic acids over periods of 4 to 6 weeks.

Experimenters found that oral application of charcoal (from 200 to 400 g/day), sauerkraut juice and humic acids influenced the antibody levels to C. botulinum, indicating reduced gastrointestinal neurotoxin burden. They found that when the feed supplements were ended, antibody levels increased, indicating that regular feeding of charcoal and other supplements had a tonic effect on cow health.

Biochar as soil conditioner

In certain poor soils (mainly in the tropics), positive effects on soil fertility were seen when applying untreated biochar. These include the higher capacity of the soil to store water, aeration of the soil and the release of nutrients through raising the soil’s pH-value. In temperate climates, soils tend to have humus content of over 1.5%, meaning that such effects only play a secondary role.

Indeed, fresh biochar may adsorb nutrients in the soil, causing at least in the short and medium term – a negative effect on plant growth. These are the reasons why in temperate climates biochar should only be used when first loaded with nutrients and when the char surfaces have been activated through microbial oxidation.

The best method of loading nutrients is to co-compost the char. This involves adding 10–30% biochar (by volume) to the biomass to be composted. Co-composting improves both the biochar and the compost. The resulting compost can be used as a highly efficient substitute for peat in potting soil, greenhouses, nurseries and other special cultures.

Because biochar serves as a carrier for plant nutrients, it can produce organic carbon-based fertilizers by mixing biochar with such organic waste as wool, molasses, ash, slurry and pomace. These are at least as efficient as conventional fertilizers, and have the advantage of not having the well-known adverse effects on the ecosystem. Such fertilizers prevent the leaching of nutrients, a negative aspect of conventional fertilizers. The nutrients are available as and when the plants need them. Through the stimulation of microbial symbiosis, the plant takes up the nutrients stored in the porous carbon structure and on its surfaces.
A range of organic chemicals are produced during pyrolysis. Some of these remain stuck to the pores and surfaces of the biochar and may have a role in stimulating a plant’s internal immune system, thereby increasing its resistance to pathogens. The effect on plant defence mechanisms was mainly observed when using low temperature biochars (pyrolysed at 350° to 450°C). This potential use is, however, only just now being developed and still requires a lot of research effort.

Biochar as construction material

The two interesting properties of biochar are its extremely low thermal conductivity and its ability to absorb water up to 6 times its weight. These properties mean that biochar is just the right material for insulating buildings and regulating humidity. In combination with clay, but also with lime and cement mortar, biochar can be added to clay at a ratio of up to 50% and replace sand in lime and cement mortars. This creates indoor plasters with excellent insulation and breathing properties, able to maintain humidity levels in a room at 45–70% in both summer and winter. This in turn prevents not just dry air, which can lead to respiratory disorders and allergies, but also dampness and air condensing on the walls, which can lead to mould developing.

As per study by the Ithaka Institute’s biochar-plaster wine cellar and seminar rooms in the Ithaka Journal. Such biochar-mud plaster adsorbs smells and toxins, a property not just benefiting smokers. Biochar-mud plasters can improve working conditions in libraries, schools, warehouses, factories and agricultural buildings.

Biochar is an efficient adsorber of electromagnetic radiation, meaning that biochar-mud plaster can prevent “electrosmog”. Biochar can also be applied to the outside walls of a building by jet-spray technique mixing it with lime. Applied at thicknesses of up to 20 cm, it is a substitute for Styrofoam insulation. Houses insulated this way become carbon sinks, while at the same time having a more healthy indoor climate. Should such a house be demolished at a later date, the biochar-mud or biochar-lime plaster can be recycled as a valuable compost additive.

Biochar as decontaminant

As a soil additive for soil remediation – for use in particular on former mine-works, military bases and landfill sites.

Soil substrates – Highly adsorbing and effective for plantation soil substrates for use in cleaning wastewater; in particular urban wastewater contaminated by heavy metals.

A barrier preventing pesticides getting into surface water – berms around fields and ponds can be equipped with 30-50 cm deep barriers made of bio-char for filtering out pesticides.

Treating pond and lake water – bio-char is good for adsorbing pesticides and fertilizers, as well as for improving water aeration.

Use of biochar in wastewater treatment – Our Project

The biochar grounded to a particle size of less than 1.5 mm and surface area of 600 – 1000 m2/g. The figure below is the basic representation of production of bio-char for wastewater treatment.

We conducted a study for municipal wastewater which was obtained from a local municipal treatment plant. The municipal wastewater was tested for its physicochemical parameters including pH, chemical oxygen demand (COD), total suspended solids (TSS), total phosphates (TP) and total Kjeldahl nitrogen (TKN) using the APHA (2005) standard methods.

Bio filtration of the municipal wastewater with biochar acting as the bio adsorbent was allowed to take place over a 5 day period noting the changes in the wastewater parameters. The municipal wastewater and the treated effluent physicochemical.

The COD concentration in the municipal wastewater decreased by 90% upon treatment with bio-char. The decrease in the COD was attributed to the enhanced removal of bio contaminants as they were passed through the bio char due to the bio char’s adsorption properties as well as the high surface area of the bio char. An 89% reduction in the TSS was observed as the bio filtration process with bio char increased from one day to five days

The TKN concentration in the wastewater decreased by 64% upon treatment with bio char as a bio filter. The TP in the wastewater decreased by 78% as the bio filtration time with bio char increase. The wastewater pH changed from being alkaline to neutral during the treatment with bio char over the 5 day period

Use in Textiles

In Japan and China bamboo-based bio-chars are already being woven into textiles to gain better thermal and breathing properties and to reduce the development of odours through sweat. The same aim is pursued through the inclusion of bio-char in shoe soles and socks.

3 Ways Zero Valent Iron Can Help in Environment Protection

Zero Valent Iron (ZVI) was developed to eliminate chlorinated hydrocarbon solvents in the soil. Industrial solvents are replete with chlorinated hydrocarbon, so much toxic and bad for the environment. They get disposed in the soil along with other toxic elements to cause harm to our surrounding. In the current years, significant improvements have taken place in the realm of iron-based technology.

Zero Valent Iron can be effectively used in soil remediation

The result of years of research and significant improvement in the iron-based technology is the advent of nanoscale or polymer-supported iron-containing nanoparticles to remove contaminants from solvents and soil. This is all due to the high surface area to the volume ratio of such nanoscale particles that favor the reaction kinetics and sorption.

But, know one thing that high pressure drops may restrict fixed-bed column application. This is why we now have modified nanosized ferrous particles to facilitate arsenic removal. The fabulous reducing agent helps in pollution recovery, and thus it benefits our environment.

Applications of Zero Valent Iron

ZVI in recent times is used widely for wastewater treatment, groundwater, and soil treatment. If made through the physico-chemical process in combination, the ZVI may be very small particles, having a large surface area. ZVI is beneficial for the environment, for it has a strong reductibility, great purity, long aging property, and similar features.

Zerovalent Iron can boost the chlorine removal efficiency of the soil, groundwater, and six valent chromium. Thus, it reduces the time required for environmental remediation. Acting as a fabulous reducing agent, it facilitates pollution recovery. Indeed, you may also combine it to bioremediation to further improve the efficacy of environment pollution recovery. Use it in the soil, solvents and industrial wastewater confidently to get rid of the contaminants. The use of ZVI paves the way for pure water and soil.

What you should look for in ZVI?

Are you planning to procure zero valent elemental metallic ions for wastewater treatment or soil remediation? Zerovalent metals or ZVI has a wide range of applications that range from electrodes and trenches to filters. Yes! It helps in the water filtration process, and thus we have pure drinking water. It gets rid of every trace of impurity or contaminant from the solvent or soil. It is important to look for a reliable company to procure ZVI.

Watch out for the following properties of ZVI

  • The particles must be fine enough to be customized as per your application
  • Look for the great adsorption performance and sound chemical activity
  • A large surface area for that very strong reductibility
  • Make sure the duration of its effect is very long to reduce the injections
  • Very fine ZVI particles to remediate pollution and to save remediation time and effort
  • Must be environment-friendly, deprived of any toxic compound

Enhanced nitrate-removing potential

Zero-valent metal has an enhanced nitrate removal capacity. It eliminates nitrate from the groundwater to facilitate remediation. Hence, biochar-supported ZVI can facilitate nitrate removal while the ones with wider pH can remove larger nitrates. Biochar composite eliminates nitrate from the groundwater without leaving any harmful by-products. But, biochar has a variable nitrate-removal capacity.

ZVI biochar has a potential to reduce nitrate by mediating the redox potential, the electron transfer, pH and thus facilitates enhanced removal or reduction of nitrate from the solvent or soil. Everything revolves around the logic of intensifying chemical reduction in order to eliminate nitrate from the soil or groundwater.

Nitrate and How it Accumulates

Nitrate is the form of nitrogen, which lies beneath the cultivable land. Nitrate is water soluble and may move through the soil quite easily. Owing to its high mobility, it moves to the groundwater table. Once it has moved to the groundwater table, it persists there and deposits to a very high level.

Thus, shallow groundwater is also at a risk of contamination from chemicals of land surfaces. This is a matter of concern, and indeed, nitrate in water may harm human health, aquatic life, livestock life and contaminate the surface water. We can say that it is not that harmful to adult humans, but it can significantly affect the health of the infants. It may reduce the level of oxygen in the blood to cause ‘blue baby’ disorder.

Hence, biological denitrification, ion exchange, and reverse osmosis are the treatment processes to handle this issue. The use of ZVI is a way to denitrification and the key to attaining a safe nitrate level in the water. A zero-valent metallic reduction is an effective way to refine dirty and polluted water. As soon as ZVI is placed in the flowing water or is added to the flowing water, there starts the process of oxidizing. The resultant chain reaction will purify water or remove the contaminants.

A Tool to Remediate Acid Mine Drainage

AMD or Acid Mine Drainage is the most common source of metal in places like the Appalachians, Tennessee, and Kentucky. It is important to remediate acid mine drainage for it is highly acidic and toxic. It is the major contributor to the arsenic environment and something needs to be done. AMD is a rich source of heavy and corrosive metals, acidic in nature. Biological treatment of Acid Mine Drainage is cost-effective, efficient and environment-friendly.

Biotechnological processes are an asset when it comes to treating Acid Mine Drainage in an effective manner. ZVI is environmentally sustainable. When it is very complicated and difficult to treat or remediate Acid Mine Drainage, ZVI eases the process. It gets rid of harmful elements or potentially hazardous substances from AMD to separate metal from acid and toxic compounds. There isn’t a need to abandon a mine site just because there are acidic metal deposits. Mine metals can be reclaimed with ZVI, and herein lays the environmental benefit.

Recycling of metallurgical waste

It is important to treat AMD or Acid Mine Drainage. The ecological solution to separate toxic metals, to reclaim water in large quantities is gaining a lot of attention. ZVI and zero valent metals save our natural resources and prepare the toxic metals for the recycling process. This is only possible through the separation of the acidic part.

We can recycle gallons of water that lay in the pond and other water bodies. It drops the acid level in the water and metal while also prevents heavy metallic reactions. When Acid Mine Drainage is one of the serious concerns in the realm of coal mining, zero valent metals prevent any exposure of sulfur-rich mineral to the water and atmospheric oxygen.

Final Thoughts

Zero-valent metals can help in the treatment of contaminated zones through the process of remediation. Zero valent iron is the highly reactive powder for remediation of wastewater and soil and works fabulously on environmentally contaminated areas. This remediation solution is highly efficient and benefits our environment in multiple ways.