One of the main ways to combat water pollution is a biological wastewater treatment using activated sludge aerated devices. By this method, the drains continuously served the treatment plant (aeration tank, etc.), and the output is the treated water. The cleaning process produces sludge (waste activated sludge with aeration tanks and sludge with anaerobic). Itself consists of activated sludge suspended solids, not detained in primary sedimentation tanks and adsorbed colloidal substances with breeding them microorganisms: bacteria, fungi, yeasts, actinomycetes, algae, protozoa, insect larvae and other organisms. The composition of the activated sludge depends on the composition of the sewage content of salts, oxygen, temperature, pH, etc. Admission drains various enterprises in urban wastewater treatment plants has led to what has accumulated a number of heavy metals and trace elements. Heavy metals are the most common group of toxic, inert to biochemical oxidation of contaminants. Due to the toxicity of such sediments they are not used as fertilizer and piled on public landfills (silt fields), the area of which is continuously increasing, turning them into a zone of ecological disaster.In this paper we look at ways of neutralization of waste activated sludge, its use in cement kilns. Known methods of disposal of surplus active sludge containing heavy metals (thermal and/or thermal treatment), despite the external appeal, ecologically safe, because in one way or another is going on air pollution, require complex treatment system of gas emissions from polluting substances, secondary wastewater treatment.