Solid fertilizer prodn. from waste water treatment slurry - coagulated with ground rock, mixed with fertilizer salts then dried

摘要

Solid, spreadable complete fertiliser for biological soil conditioning and improving plant yields consists of sterile, granulated organic slurry (A) from biological waste water treatment plants which has been coagulated with ground primitive rock (B). Inorganic fertiliser salts are then added to prevent rotting and the compsn. dried. Pref. (B) has grain size 0-500, esp. 0.1-100 mu and is esp. derived from basalt or slate. The wt. ratio (B): dry matter in (A) is 0.1:1-10:1, esp. 1:1. The fertiliser salts are 1:1. The fertiliser salts are 10-25 wt.% (on dried granulate) and esp. comprise an NPK fertiliser also contg. Ca, Mg and trace elements. They are added as soln., suspension or powder. Compsn. is suitable for use in agriculture, horticulture or forestry. The compsn. is applied easily and feeds not only the plants but also the symbiotic soil flora and fauna. (B) is a very effective coagulant for slurry without altering the pH or introducing soluble components into the slurry.