NOVELTY - Preparing biological carrier involves mixing pretreated monobromoacetic acid (MBAA) with attapulgite in saline water and stirring at 50-70 degrees C for 1-3 hours. The biopolymer solution is mixed with the obtained solution, and heated at 40-60 degrees C. Attapulgite (2-5 wt.%) is added to the activated sludge along with iron, manganese composite oxide (1-3%) and stirred for 1-3 hours at the stirring speed of 5-10 rotations per minute.    USE - Method for preparing biological carrier used for treating and purifying waste water (claimed).    ADVANTAGE - The method enables to prepare biological carrier with stability, good elasticity and high wear resistance strength in a simple and easy way, where the carrier efficiently removes pollutants in waste water.    DETAILED DESCRIPTION - Preparing biological carrier involves mixing pretreated monobromoacetic acid (MBAA) with attapulgite in saline water and stirring at 50-70 degrees C for 1-3 hours. The biopolymer solution is mixed with the obtained solution, and heated at 40-60 degrees C. Attapulgite (2-5 wt.%) is added to the activated sludge along with iron, manganese composite oxide (1-3%) and carbon nanotubes (2-5 wt.%), and stirred for 1-3 hours at the stirring speed of 5-10 rotations per minute. Cyclodextrin complex solution is then added to the obtained mixture, followed by stirring at 20-30 degrees C for 20-40 minutes, and then the solution is placed at 10 degrees C for 30 minutes. The temperature is adjusted to -5 degrees C to -7 degrees C along with stirring for 40-60 minutes. The solution is cured, crosslinked, pressed and wrapped in a gauze. Tannic acid solution (10-20%) is added, and the solution is rinsed 2-3 times. The mixture is placed in an oven at 50-70 degrees C for 8-10 hours after treatment. INDEPENDENT CLAIMS are included for:    (1) a method for preparing carbon nano tubes, which involves soaking carbon nanotubes (20-30 wt.%) in an aqueous solution of methanol (10-25 vol.%) for 30-50 minutes, performing centrifugation and collecting the precipitate;    (2) a method for preparing biopolymer solution, which involves mixing polyglutamic acid fermentation liquid with Ganoderma lucidum fermentation culture liquid in the ratio of 1:6-8, heating and concentrating to 10-40 vol.%; and    (3) a method for pre treating attapulgite, which involves crushing attapulgite to a particle size of 300-1000 meshes, adding methanol solution (15-35%), controlling the temperature to 45-50 degrees C and treating with pulse processing power; placing the solution for 1-2 hours for precipitation and taking the supernatant; adding a small amount of distilled water to the supernatant, mixing continuously and centrifuging for 1 minute at 500 rotations per minute (rpm); washing the supernatant repeatedly for 3-5 times, centrifuging at 2000-3000rpm, and drying the precipitate under vacuum at 90 degrees C for 24 hours; and crushing according to the particle size after grinding to 200-400 mesh sieve, and collecting attapulgite soil.