Method for preparing liquid fertilizer by using sludge hydrothermal carbonization waste liquid

The present invention relates to a method for preparing a liquid fertilizer by using sludge hydrothermal carbonization waste liquid. According to the method, sludge is used as a raw material, the sludge and a conditioning agent are mixed, the mixture is subjected to hydrothermal carbonization treatment in an inert gas environment atmosphere to obtain hydrothermal carbonization waste liquid, and alarge amount of elements, a large amount of trace elements and the pH value of the mixture obtained through the evaporation concentration of the hydrothermal carbonization waste liquid are adjusted toobtain the high-quality liquid-state fertilizer, such that the resource utilization of the organic waste liquid is achieved, the environmental pollution is reduced, and the economic benefits are created; and the method has advantages of simple steps, easy performing, low cost and easy promotion and application, and the prepared fertilizer has characteristics of safety and excellent fertilizer efficiency. 本申请涉及种利用污泥水热碳化废液制