A soil particle in which a hydrophobic property is imparted to a soil powder, the change for contacting algae is increased, - ions attracted to + charges destroy cell walls, and agglomeration and precipitation occur. When massive reproduction of algae causes a red tide or green tide phenomenon to occur, and a loess suspension is sprayed, most of the loess suspension quickly precipitates and thus has a low chance of reacting with algae. Thus the loess suspension has a low effectiveness compared to the amount used, and can be a source of secondary pollution. A powder obtained by grinding loess or kaolin is neutralized and washed by being immersed in an acidic solution, and the soil suspension is pulverized by being sonicated and subjected to precipitation and drying to obtain a fine powder, which is placed into a furnace. An insulator or surfactant is dissolved in an organic solvent and evaporated, a hydrophobic property is imparted to the fine powder through mixing, and the mixture is dried through the emission of high frequency waves and reduced pressure, and cooled and stored under sealing to enable spraying in a region in which a green tide or red tide phenomenon has occurred. The soil particle alleviating green tide or red tide phenomena is characterized in that the formation of lumps during storage is minimal, spraying may be quickly performed over a large area, the amount of spray that is blown far away may be reduced, the residence time on the surface of the water or in the water is increased, algae is destroyed by - ions following changes to + charges, and soil usage is reduced through agglomeration, precipitation, and dissolution.흙 분말에 소수성을 부가하고 조류에 접촉할 기회를 높이여 + 전하에 끌린 - 이온으로 세포벽을 파괴하고, 응집 침전시키는 흙 미립자이다.조류의 다량 번식으로 적조 또는 녹조현상이 발생하여 황토 현탁액을 뿌리면 대부분 빨리 침전하여 조류와 반응할 기회가 적어서 사용량에 비해 효과가 작고 2차 오염원이 될 수 있다.황토 또는 고령토를 파쇄한 가루를 산성용액에 담그고 중화하여 세척하고, 흙 현탁액에 초음파를 조사하여 파쇄하고 침전 건조하여 분말로 만들어 가열 솥에 넣고, 절연체 또는 계면활성제를 유기 용매에 녹여 기화시켜 소수성을 혼합으로 부가시키고, 고주파 조사와 감압하여 건조하고, 냉각
