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KR-20260064857-A - Production method of Biochar Modified with Deep Sea Water and Removing Method of Phosphate in Aqueous Solution Using the Biochar Produced This Method

KR20260064857AKR 20260064857 AKR20260064857 AKR 20260064857AKR-20260064857-A

Abstract

The present invention relates to a method for producing biochar modified with deep sea water and a method for removing phosphorus in an aqueous solution using the biochar produced by the said method. More specifically, the invention relates to a method for producing biochar modified with deep sea water and a method for removing phosphorus in an aqueous solution using the adsorption properties of the biochar produced by the said method, comprising: 1) a step of washing a biochar raw material containing agricultural by-products with running water; 2) a step of drying the washed raw material, crushing it to a diameter of 1.50 to 5.00 mm, and pyrolyzing it under oxygen-limited conditions; and 3) a step of producing modified biochar by sufficiently mixing the pyrolyzed raw material with raw water or concentrated water of deep sea water, filtering it, and drying it. The biochar chemically modified by deep sea water according to the present invention is proven to be highly effective in removing phosphates under water-soluble conditions, thereby acting as an eco-friendly bioadsorbent with enhanced adsorption capacity; thus, it can be used as a promising product for maintaining or increasing soil productivity, reducing nutrient loss, and purifying water quality in ecosystems through the conversion of the modified biochar into biomass.

Inventors

  • 오세진
  • 양태희

Assignees

  • 재단법인 해양심층수산업 고성진흥원

Dates

Publication Date
20260508
Application Date
20241029

Claims (8)

  1. 1) A step of washing biochar raw materials containing agricultural by-products with running water; 2) a step of drying the washed raw material, crushing it to a diameter of 1.50 to 5.00 mm, and pyrolyzing it under oxygen-limited conditions; and 3) a step of producing modified biochar by sufficiently mixing the above-mentioned pyrolyzed raw material with raw water or concentrated water of deep sea water, filtering, and then drying; a method for producing biochar modified with deep sea water.
  2. A method for producing biochar modified with deep sea water according to claim 1, characterized in that the agricultural byproduct is selected from the group consisting of rice (rice husk or rice straw), chili peppers, soybeans, potatoes, sesame, napa cabbage, radish, corn, and fruit tree pruning branches (apple, grape, or peach).
  3. A method for producing biochar modified with deep sea water according to claim 2, characterized in that the rice, chili pepper, soybean, and potato are each rice husk, chili pepper stem, soybean stem, and potato stem.
  4. A method for producing biochar modified with deep sea water according to claim 1, characterized in that the pyrolysis is carried out by increasing the temperature at a rate of 10℃/min to the target pyrolysis temperature and for 1 to 3 hours at a final pyrolysis temperature of 350 to 550℃.
  5. A method for producing biochar modified with deep sea water according to claim 1, characterized in that the concentrated deep sea water reduces the volume of the raw water by 20 to 50%.
  6. A method for manufacturing biochar modified with deep sea water according to claim 1, characterized in that the biochar raw material and deep sea water are mixed in a solid-to-liquid ratio of 1:2 to 1:5.
  7. A method for producing biochar modified with deep sea water according to claim 1, wherein the modification of the biochar raw material in step 3) is mixed with deep sea water for 6 to 36 hours. .
  8. A method for removing phosphorus in an aqueous solution using the adsorption properties of biochar produced by the method of claim 1.

Description

Production method of Biochar Modified with Deep Sea Water and Removal Method of Phosphate in Aqueous Solution Using the Biochar Produced This Method The present invention relates to a method for producing biochar modified with deep sea water and a method for removing phosphorus from an aqueous solution using the biochar produced by the said method. Biochar is a carbon-rich adsorbent produced by pyrolysis of biomass under limited oxygen conditions at specific temperatures, and it is attracting attention as a multifunctional material for reducing atmospheric carbon, reducing greenhouse gas emissions through carbon fixation, improving soil, and fixing pollutants (El-Naggar et al., (2019) Geoderma, 337, 536-554; Feng et al., (2023) Biochar, 5, 22; Lehmann and Joseph, (2009) Biochar Environ Manage Sci Technol, 25, 15801-15811; Valizadeh et al., (2021) Environ Res, 200, 111757; Wang and Wang, (2019) J Clean Prod, 227, 1002-1022). Among the factors determining the characteristics of biochar, the type of raw material is broadly classified into plant-based and animal by-products. While plant-based materials are advantageous for adsorbing non-polar substances due to their low polarity, animal-based materials are rich in minerals, making them more suitable for use as adsorbents through the functional groups present on the surface of the product. The physicochemical properties of biochar are primarily determined by the raw materials and pyrolysis conditions (residence time, temperature, heating rate, and reactor type, etc.), and recently, waste resources generated from agriculture, fisheries, and forestry, which are easily accessible, are being utilized mainly in terms of raw material procurement and cost (El-Naggar et al., (2019) Geoderma, 337, 536-554; Panahi et al., (2020) J Clean Prod, 270, 122462; Tomczyk et al., (2020) Rev Environ Sci Bio, 19, 191-215; Zhao et al., (2022) Fuel, 313, 122979). Pyrolysis temperature is known to have a significant effect on the yield of products obtained from raw materials, as well as on the surface structure and the formation of functional groups. The heating rate and residence time at the final production temperature determine the amount of inorganic carbon, the lamination of aromatic carbon, and the graphitization of the carbon structure during the secondary char formation process through the removal of volatile substances via the adjustment of the yield of solid, liquid, and gaseous products in the raw material and through secondary reactions between char particles and volatile substances (Lehmann and Joseph, (2015). Routledge). Generally, the raw materials used in biochar production are mostly plant-based materials that are effective for adsorption and soil improvement; however, because their adsorption efficiency and soil improvement effects are lower compared to animal-based materials, attempts are being made to enhance performance through physical and chemical modifications at post-treatment or pre-carbonization stages to improve pores, specific surface area, and functional groups (Feng et al., (2023) Biochar, 5, 22; Lee and Shin, (2021) J Environ Manage, 299, 113651; Mukherjee et al., (2011) Geoderma, 163, 247-255; Panahi et al., (2020) J Clean Prod, 270, 122462; Rajapaksha et al., (2016) Chemosphere, 148, 276??291; Uchimiya et al., (2011) J Hazard (Mater, 190, 432-441; Xu et al., 2021). Physical modification utilizes ball milling, gas and steam activation, and microwaves without chemical additives, offering economic advantages. Chemical modification, on the other hand, is the most widely used method to improve performance by treating surfaces with acids and bases to oxidize or impregnate them. According to prior research , acids such as H₂SO₄ , HCl, HNO₃ , and citric acid, or alkalis such as KOH and NaOH, are primarily used as additives for modification. It has been reported that efficiency improves after modification due to increased adsorption capacity and surface electrostatic force resulting from the increase in carboxyl groups, hydroxyl groups, and meso/micro-pore volumes. However, since most additives are strong acid or base chemicals, consideration of environmental impact is necessary. Consequently, research on the applicability of additives that are relatively more environmentally friendly than existing additives, such as those utilizing phosphate compounds, has recently been increasing. Meanwhile, deep sea water is seawater found in deep oceans at depths of 200 m or more. It is clean, free of organic matter and pathogens, and is known as a unique, mineral-rich, eutrophic resource that maintains a stable low temperature year-round, serving as an alternative resource to address the depletion of limited resources on land. Furthermore, although it is an abundant resource accounting for 95% (1.3 x 10⁹km³ ) of seawater, the areas where it can be extracted are very limited, including Korea, the United States, Japan, Taiwan, and Australia (Ju, (2016) J Korean Acad-Ind Coop