They are considered as hazardous waste, and it is essential to carry out a correct, safe and sustainable treatment for their final disposal. The existence of three types of sludge generated during the water treatment stages of each industry is evident. The solutions are proposed under an individual analysis, starting with the origin of the sludge, whether industrial or municipal, continuing according to the stage and type of water treatment in which it has been generated, concluding with the type of treatment to be carried out for its final disposal obtaining a liquid and solid phase.

Through innovative solutions, the maximum recovery of useful materials for applications such as fertilizer or biogas is proposed.