NOVELTY - A biological flocculant (I), comprises (a) Bacillus bacteria (also in culture) with a flocculating effect towards kaolin suspensions or industrial wastewater where culture further has (i) carbon or nitrogen source, or (ii) lactic fermentation wastewater.    USE - (I) is useful for treating water, which involves adding 2 ml/l of (I). (II) is useful for treating water, which involves introducing (II) into water. The soybean protein has a concentration of 15-120 g/l. The soybean is introduced in a dosage of 0.2-0.5 ml/l. (III) is useful for treating water, which involves mixing powders of (III) with tap water into 1% powder solution, adjusting pH of 500 ml of water to be treated, and introducing 1 ml of 1% powder solution into the 500 ml water. The pH ranges from 6.3-6.5, and the pH is adjusted by adding poly aluminum chloride. The water is wastewater from the food industry (claimed).    ADVANTAGE - (I) has the same flocculating effect as chemical flocculants and the production cost is less due to low raw material cost and high bacteria recovery rate.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following:    (1) a biological flocculant comprising a fermented solution containing the culture of (I), or precipitates collected from the culture of (I);    (2) a flocculant (II) comprising soybean protein with a concentration of at least 15 g/l;    (3) a flocculation agent comprising ferric chloride or aluminum chloride, and (I) or (II);    (4) making (M1) a biological flocculant, comprising inoculating Bacillus bacteria having flocculating effect towards kaolin suspensions or industrial wastewater onto a culture medium and incubating it for 60-108 hours;    (5) making (M2) a powdered biological flocculant, comprising inoculating Bacillus bacteria having a flocculating effect towards kaolin suspensions or industrial wastewater onto a culture medium and incubating it for 60-108 hours, and spray drying the culture medium;    (6) a bacterial culture fermentation process, comprising preparing a culture comprising Bacillus bacteria having flocculating effect towards kaolin suspensions or industrial wastewater, glucose, soybean protein, molasses, and yeast, fermenting the culture under temperatures between 28-30degreesC for 40-48 hours, setting ventilation volume to 0.5-1 VVM, and adjusting initial pH of the culture to 6-7;    (7) a powdered biological flocculant (III) comprising a spray dried culture medium of Bacillus bacteria; and    (8) activating preserved bacterial strain, comprises streaking the preserved Bacillus bacteria having flocculating effect towards kaolin suspensions or industrial wastewater onto tryptic soy agar of a concentration of 40 g/l and incubating the culture for 1-2 days under 30degreesC.