The purification of sewage from washing of concrete mixing and transport equipment

Ecological safety of construction

The modern equipment for preparation and transportation of cement mortals needs professional service and, first of all, in its washing up from the rests of cement after operation. Increasing volumes of the waters used for these purposes, demand working out of technologies of their clearing of the weighed and dissolved substances, correction рН, recyclings of deposits, etc. 

The waters formed after a sink of the concrete-mixing equipment, represent difficult diphasic system. The liquid phase of such waters is the concentrated solution of silicates, aluminates and ferrite of calcium, sodium and potassium, and also their alkalis. The firm phase consisting of not dissolved parts of clinker, is present at these waters in significant amounts and is hydrolyzed within solubility of its separate components. Insoluble parts клинкера in water adsorb various ions, their surface gets defined ξ potential which size the aggregative stability of suspension depends on. 

In the given work physical and chemical characteristics of sewage form washing of concrete mixing equipment are investigated. The technological possibilities of chemical treatment of sewage by acids, hydrocarbonate of sodium and gaseous carbon dioxide for purpose of depression of the general salt content in these waters and their use in technological process as the turnaround are analysed.