How to use biochar as a water contaminants detoxifier in fish farming

Pictures of Biochar sacks in fishpond

Aquatic pollution, causes, and effects on fish farming

Toxic contaminants end up in our state’s waterbodies in different ways. Industrial and municipal discharges, agricultural practices, and stormwater runoff can all put harmful substances into the water. Rain can also wash chemicals from the land or air into streams, rivers, lakes, and Puget Sound. Toxic contaminants enter our state’s waters in a variety of ways. Industrial and municipal waste, agricultural activities, and stormwater runoff can all release toxic substances into water. Rain can also wash chemicals from the soil or air into streams, rivers, and lakes.

Contaminants such as polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers, dioxins, and chlorinated pesticides are present in water, sediment, and food consumed by fish. In polluted areas, bottom fish (certain fish species that live at or near the bottom of a body of water) are especially likely to contain high levels of these chemicals because these substances settle to the bottom where they feed. The health risk to humans eating contaminated fish and seafood is that contaminants can build up in the human body over time. It can take five years or more for women in their childbearing years to rid their bodies of PCBs, and 6-12 months to reduce their mercury levels significantly. Mercury, PCBs, and other contaminants can be passed on to a developing fetus through the placenta.

The increasing global contamination of water systems by industrial or natural substances constitutes one of humanity’s major environmental problems. Most of these aqueous substances exist in low concentrations; however, their long-term contamination can cause severe toxicity problems. Water quality assessment requires the implementation of appropriate and cost-effective technologies to effectively remove microscopic pollutants while ensuring the maintenance of essential components of aquatic life, such as the presence of individual minerals, etc. Developing such technologies often involves dangerous chemicals that are not environmentally friendly. Therefore, there is an urgent need for suitable “functional” ecological materials that can easily reduce the number of micropollutants in aquatic systems. Commonly used functional materials have significant limitations due to their dependence on fossil fuels and energy-intensive melting conditions. A renewable carbon-rich biomaterial that could be a promising alternative to other carbon materials used in the production of water pollution treatment equipment has been proposed to solve the problem.

Methods of regulating contaminants in aquaculture facilities

1. Biochar – The physical and chemical properties of Biochar has high charge and surface area, making it ideal for pond water treatment in the same way that Biochar is used in activated carbon filtration in potable water. Biochar is great at absorbing pesticides and fertilizers to help keep your waterways free of harmful compounds and has demonstrated its potential to remove heavy metal ions from water.

Biochar as a detoxifier in fish culture facilities

Biochar is a carbon-rich material produced from the pyrolysis of biomass in a closed system by a reduction reaction. This material is called “biochar” and is defined as the fine-grained carbon and ash biological product obtained from anaerobic biomass digestion. Biochar material has strong water and nutrient adsorption capacity, is very stable, and can also remove organic/inorganic pollutants.

Aquaculture has developed many different fish production systems and is very popular in recent decades. These systems were developed to increase productivity by increasing fish density, which raises the issue of toxicity of wastewater discharged into aquatic ecosystems. Therefore, one solution to this problem is to integrate the aquaculture system with the toxicity control method of Biochar, where Biochar can adsorb and dissolve compounds from wastewater. Soluble compounds contain two main components: nitrogen and phosphorus compounds from fish feed. Nitrogen and phosphorus are retained in the fish’s body, and a certain amount is released into the culture water, over time causing eutrophication.

Eutrophication refers to the process by which water gradually accumulates high nitrogen and phosphorus concentrations. This process can lead to a decrease in oxygen in the water after the algae is decomposed by bacteria.

Aquabiochar refers to the integration of aquaculture and biochar as water toxicity regulators and detoxifiers.

2. Biofloc technology (BFT) is considered the new “green revolution” because nutrients can be continuously recycled and reused in the growing medium, benefiting from minimal or no water changes. Furthermore, the sustainable approach of such a system depends on high fish/shrimp production in small areas. In addition, bioflocs provide a food source rich in natural proteins and lipids that are locally available 24 hours a day due to the complex interactions between organic matter, physical substrates, and various microorganisms. This natural productivity plays an important role in recycling nutrients and maintaining water quality. Biofloc technology (BFT) systems have emerged as practical and inexpensive solutions to meet the above prerequisites for sustainable aquaculture development. BFT works on the accumulation of inorganic nitrogen, one of the main problems faced in the aquaculture industry.

Advantages and Significance of Biochar in Fish Facilities

• Putting Biochar into fishponds filters the turbidity of suspended substances in the water, reduces heavy metal content, and reduces accumulation in fish organs, especially using sawdust biochar; next is rice husk biochar.
• Blood spawning results of tilapia under biochar conditions are closely related to the absence of stress and good water quality in the hatchery, which directly improves reproductive performance.
• The survival rate of fry increased, perhaps due to the improvement achieved using Biochar.
• Using wastewater for aquaculture is a new trend, and its important impact focuses on reusing “waste” water, which contains many viruses, bacteria, and microorganisms. The effectiveness of removing bacteria from wastewater by passing through a filter depends on the adsorption capacity of the filter material and the properties of the biofilm formed on the filter surface.
• Adding Biochar to aquaculture can increase the surface area of ​​contact between water and air, helping to regulate the amount of dissolved oxygen needed for warm water fish farming.
• Finally, the pH of the aquatic water is further adjusted by the adsorption of Biochar.

Conclusion

Biochar is the most effective and environmentally friendly method of eliminating toxicities in aquatic facilities while creating a conducive breeding ecology for fish reproduction. This method seeks to protect consumers by purifying the water and absorbing contaminants from water bodies and fishes which tends to affect consumers that feed on contaminated fishes.

References

• Food and Agriculture Organization of the United Nations (FAO), Rome modified corn biochar for phosphorus removal and recovery from Swine wastewater. Int J Environ Res Public Health. 2014 Sep 5;11(9):9217-37.
• Mohan, D., Sarswat, A., Ok, Y.S. and Pittman Jr, C.U., 2014. Organic and inorganic contaminants removal from water with biochar, a renewable, low cost and sustainable adsorbent–a critical review. Bioresourcetechnology,160, pp.191-202. https://www.researchgate.net/profile/Arvind_Singh56/post/What_is_remove_biochar_in_wastewater_treatment/attachment/59fb0fd94cde26d68ce667f3/AS:556225148719105@1509625817538/download/BRTReview.pdf
• Biofloc Technology (BFT): A tool for water quality management in Aquaculture Mauricio Gustava Coelho emerenciano, Luis Rafael Martinez-Cordova, Marcel.
• Martínez-Porchas and Anselmo Miranda-Baeza, submitted: 22 March 2016 Reviewed: 19 October 2016 Published: 18 January 2017