Method for removing heavy metals from composted organic waste used as horticultural substrate in potting soil for growing trees, involves sieving composted organic waste through sieve bodies that are provided with apertures

摘要

The method involves sieving composted organic waste through sieve bodies provided with apertures. The waste particles with average mesh size are subjected to filtrating process for removing heavy metals. Residual waste particles are washed with water (4). The residue water is withdrawn from waste particles after washing. The pH is reduced up to around 1.5 after washing the waste particles. An acid containing solution is added with residue water, where the acid is selected from oxalic acid, formic acid, citric acid, sulphurous acid, sulfuric acid, nitric acid or hydrochloric acid. An independent claim is also included for a device for removing heavy metals from composted organic waste.