Preparation method of sewage sludge compound fertilizer

Abstract

The invention discloses a preparation method of a sewage sludge compound fertilizer. The preparation method of the sewage sludge compound fertilizer mainly comprises the following steps: adding industrial waste acid into urban domestic sludge or industrial sludge which is sterilized and disinfected by a conventional method to adjust the pH value to a range of 0.5-3, heating the sludge to 60-90 DEG C, and carrying out acidization hydrolysis under continuously stirring for 45-60 minutes; then respectively adding ore powder which accounts for 60-70% of the total weight of the sludge and contains silicon, phosphorus, calcium, magnesium, potassium and other trace elements, rice husk powder or sawn wood powder which accounts for 10-25% of the total weight of the sludge and an inorganic ammonia salt compound which accounts for 10-25% of the total weight of the sludge; preserving heat and uniformly stirring, adjusting the pH value to be neutral by using lime alkaline substances; and heating and drying the mixture and controlling the content of water in the mixture to be smaller than 18%, and prilling, metering and packing the mixture to prepare the sewage sludge compound fertilizer.

Description

Technical field [0001] The invention relates to a manufacturing process for manufacturing agricultural fertilizers from sewage sludge or similar substances, in particular to a manufacturing method for urban or industrial sludge compound fertilizer. Background technique [0002] At present, with the continuous development of industrialization and the continuous improvement of people's daily life, the environmental pollution problem in my country's vast urban and rural areas and market towns has become more and more serious. One of the most important pollution is the discharge of urban domestic wastewater and industrial wastewater. Although some new technologies and new processes have been promoted and applied in the treatment and recycling of this type of wastewater, the large amount of sludge left over is still a difficult and urgent problem to be solved. These sludge contains a large number of organic compounds and other toxic inorganic substances. At the same time, it also con...

AI Technical Summary

Problems solved by technology

This kind of sludge solid fertilizer contains a large amount of strong alkaline substances such as lime powder or cement kiln powder, with a high pH value and strong corrosion. It is not convenient to store and use, and long-term large-scale use will lead to soil compaction in farmland. , reduce fertility, and even lead to salinization of the land, making it difficult for crops to survive and grow! The production cycle of this production process is also long, so it is not easy to popularize and apply in large quantities