▎ 摘　　要

NOVELTY - A composite biosoil water retaining agent comprises 30 pts. wt. modified coconut husk fiber, 80 pts. wt. pretreated slurry, 0.2 pt. wt. wood rot fungi, 20 pts. wt. aniline, and 8 pts. wt. pretreated bone meal. The preparation method of the composite biosoil water retaining agent involves: (1) mixing coconut husk fiber, biogas slurry, glycerin, and water, fermenting, filtering to obtain a filter residue (A), drying to obtain a dried filter residue (A), then placing in a fluidized bed reactor, introducing nitrogen into the reactor to obtain a treated material, and drying to obtain a pretreated coconut husk fiber; (2) preparing modified coconut shell fiber; (3) preparing a pretreated graphene oxide; (4) preparing a pretreated slurry; (5) preparing a pretreated bone meal; (6) adding modified coconut shell fiber, pretreated slurry, wood-rot fungi, aniline and pretreated bone meal to a mixer, and mixing to obtain the product; and (7) subjecting the product to performance testing. USE - Composite biosoil water retaining agent. ADVANTAGE - The composite biosoil water retaining agent has excellent water retention performance. DETAILED DESCRIPTION - A composite biosoil water retaining agent comprises 30 pts. wt. modified coconut husk fiber, 80 pts. wt. pretreated slurry, 0.2 pt. wt. wood rot fungi, 20 pts. wt. aniline, and 8 pts. wt. pretreated bone meal. The preparation method of the composite biosoil water retaining agent involves: (1) mixing coconut husk fiber, 3 pts. wt. biogas slurry, 3 pts. wt. glycerin, and 50 pts. wt. water, fermenting in a fermentation kettle at 32 degrees C for 8 days, filtering to obtain a filter residue (A), then adding to an oven, drying at 110 degrees C to moisture content of 8% to obtain a dried filter residue (A), then placing in a fluidized bed reactor, introducing nitrogen containing 5 vol.% trimethylaluminum into the reactor at a rate of 90 mL/minute for 30 minutes to obtain a treated material, adding to the oven, and drying at 110 degrees C to constant weight to obtain a pretreated coconut husk fiber; (2) adding 30 pts. wt. pretreated coconut shell fiber and 60 pts. wt. collagen solution to a beaker (A), mixing at 800 rpm, soaking for 2 hours, filtering to obtain a filter residue (B), mixing with 60 pts. wt. 30% sodium hydroxide solution, filtering to obtain a filter residue (C), washing with glacial acetic acid until the washing liquid is neutral, adding the washed filter residue (C) to the oven, and drying at 110 degrees C to constant weight to obtain a modified coconut shell fiber; (3) adding 20 pts. wt. graphene oxide and water to a single-necked flask, placing the flask in an ultrasonic disperser, mixing and ultrasonically processing at 75 kHz for 30 minutes, then adding 3 pts. wt. sodium azide to the flask, then moving the flask to a digital display speed measuring thermostat magnetic stirrer, heating and stirring at 160 degrees C and 800 rpm for 2 hours, then adding 0.2 pt. wt. lithium aluminum hydride to the flask, heating and stirring at 160 degrees C and 800 rpm for 2 hours, then filtering to obtain a filter residue, washing 5 times with 80 pts. wt. deionized water, and drying in oven at 110 degrees C to constant weight to obtain a pretreated graphene oxide; (4) adding 3 pts. wt. agar and 120 pts. wt. water to a beaker (B), stirring with a glass rod for 20 minutes, leaving still and swelling for 5 hours, placing the beaker (B) in the magnetic stirrer, heating and stirring to dissolve at 95 degrees C and 800 rpm for 60 minutes, cooling to 32 degrees C, then adding 0.02 pt. wt. agarase to the beaker (B), stirring at 32 degrees C and 600 rpm for 60 minutes, increasing the temperature to 95 degrees C to inactivate the enzyme, then adding 10 pts. wt. pretreated graphene oxide to the beaker (B), stirring and mixing at 600 rpm for 60 minutes, and adding 20% hydrochloric acid to the beaker (B) to adjust the pH to 5.3 to obtain a pretreated slurry; (5) adding 30 pts. wt. pork bone meal, 0.2 pt. wt. lipase, 0.02 pt. wt. protease and 60 pts. wt. water to a beaker (C), then placing the beaker (C) in the magnetic stirrer, stirring and mixing at 35 degrees C and 600 rpm for 60 minutes, filtering to obtain a filter cake, drying in the oven at 110 degrees C to constant weight to obtain a dry filter cake, carbonizing the dry filter cake in a furnace at 750 degrees C for 3 hours, then filling the furnace with nitrogen at a rate of 120 mL/minute, and cooling the furnace to room temperature to obtain a pretreated bone meal; (6) adding modified coconut shell fiber, pretreated slurry, wood rot fungi, aniline and pretreated bone meal to a mixer, and mixing at 1200 degrees C for 60 minutes to obtain the product; and (7) subjecting the product to performance testing.