PROCEDURE FOR STABILIZING HIGH PH LEVELS IN BIOSOLIDS-CONTAINING PROCESSED SEWAGE PRODUCT

摘要

In accordance with one aspect of the invention a testing procedure, aprocessing procedureand a resulting product are provided whereby sewage sludge is primarily orfirstly pre-hydrolysedin whole or in part by means other than alkali. The alkali is then added tothepre-hydrolysed product. The pre-hydrolysed product from step one has a reducedpotentialfor further hydrolysis and is more effectively stabilized in step 2 as aliquid biosolids-containingproduct or BSP. As a result, in accordance with the invention less of thealkali isused up in the step 2 further alkali-based hydrolysis of the pre-hydrolysedproduct. The pHof the BSP product after the step 2 alkali treatment drops less over theperiod of storageand the BSP product will be better preserved against microbial regrowth.