Method for producing granular organic fertilizer with high content of humic acid by using municipal sludge

Abstract

The invention relates to a method for producing a granular organic fertilizer with high content of humic acid by using municipal sludge. The method is characterized by comprising the following steps of: mixing the municipal sludge, dry weathered coal powder and phosphogypsum in a weight ratio of 80-100:30-50:10-30; inoculating a ferment bacterium which is 2 to 4 percent of the total weight of raw materials into the mixture; mixing the mixture uniformly and fully; placing the mixture into a fermenting tank for aeration; performing composting fermentation for 10 to 15 days, wherein the temperature of a system can be raised to 50 to 70 DEG C in the process of fermentation; tedding and smashing the mixture; and then adding an organic aqueous binding agent which is 0.05 to 0.1 percent of the quantity of the smashed material to perform granulation to obtain the granular organic fertilizer. The method takes high-quality weathered coal powder, straws and an organic granulation binder to replace clay as materials of the municipal sludge to perform aerobic fermentation, can greatly improve the quality of the granular organic fertilizer, improves the content of organic matters from 20-25 percent to 40-55 percent, and improves the content of the humic acid from 15-20 percent to 20-40 percent; and the method solves the problem of difficult granulation of the organic fertilizer, can obviously improve the granulating ratio of the organic fertilizer in the granulation process, improves the production efficiency greatly, and reduces the energy source consumption. The obtained product has no fiber impurities, and has a greatly improved external appearance.

Description

technical field [0001] The invention relates to the technical field of organic fertilizers, in particular to a method for producing granular organic fertilizers with high humic acid content by using urban sludge. Background technique [0002] Carry out aerobic fermentation of urban sludge, add other nutrients and clay for granulation to make granular organic fertilizer, or return it to the field as loose organic soil without granulation, which is the sludge resource that some environmental protection companies have already adopted way of utilization. [0003] However, there are the following three defects in the current municipal sludge resource utilization process: [0004] 1. In the process of aerobic release, a large amount of straw materials need to be added due to the high water content of the sludge, and the crude fiber of straw materials is difficult to completely transform during the fermentation process, thus seriously affecting the subsequent granulation process,...

AI Technical Summary

Problems solved by technology

[0005] 2. Due to the use of a large amount of clay as a binder, the general dosage is 20% to 30%. On the one hand, the granulation effect is not ideal, and on the other hand, the content of organic matter and humic acid in organic fertilizer products is greatly reduced, which seriously affects product quality.

[0006] 3. The use of bulk organic soil is not used, and the market recognition is low