Activated sludge from the Bellaire, Texas, plant was acclimated to five different test compounds, 2,4-Dichlorophenol, Linear Alkylate Sulfonates, Nitrilotriacetic Acid, Ethylene dinitrilotetracetic Acid, and Ethylene glycol. The test compounds were then incorporated into wastewater influent to the Bellaire plant and fed to the acclimated sludge which had been mechanically disrupted by sonic energy, to varying degrees. Cell disruption was followed by TOC increase and cell number decrease, and on the average resulted in a significant reduction in cell numbers both at 20 minutes and at one hour. The use of disrupted cells may have some potential in waste treatment as demonstrated by substrate removal with sonically disrupted sludge or the supernate from sonically disrupted sludge.