Investigation of the technology of reagent decontamination of excess activated sludge from a secondary dump using experimental statistical models

A technology has been developed to change the resistivity of compacted excess activated sludge (EAS) by treating sludge with six types of coagulant and polyacrylamide (PAA) in doses from 0 to 200 mg/dm3. The degree of influence of each reagent on the degree of sediment dehydration has been established. Mathematical models of the dependence of the change in the resistivity of the sediment on the amount of coagulant and flocculant introduced into the sediment are obtained. Mathematical models are represented both implicitly and explicitly (by isolines). It has been proved that the process of maximum reduction of the resistivity of uncompacted excess activated sludge is more expedient to conduct coagulants: Aluminum polyoxysulfate or Ferric chloride with a dose of up to 50 mg/dm3 and flocculant PAA with a dose of 50 mg/dm3.