assignment 4

assignment 4 - Problem discussed: A 9 MGD aerobic activated...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
Problem discussed: A 9 MGD aerobic activated sludge has three aerobic digesters. They had been receiving around 90000 gallons of thickened WAS for 15 months and now cause lot of offensive odor. This has created nuisance in the place. Summary of the thread: The thread suggests that the problem is basically due to overloading of the activated sludge. The postings on the thread say that the insufficient amount of oxygen for the higher percentage of total solids (3.5% to 4%) in the plant can cause such a problem. Source of the odor can be organic acids (acetic acids, lactic acids, propionic acids etc. ..). If the tank is septic, then the major source of the odor can be organic sulfur compounds. Dewatering, lime stabilizing and dumping of the sludge to avoid the overloading of the activated sludge can be helpful in arresting the problem. Suggestions: Use of Microorganisms : There are reports in the literature (Mitsui Engineering & Shipbuilding Co., Japan) where microorganisms mainly Bacillus sp. were used to control the odor. It was verified that the excess
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 06/07/2010 for the course CE CE773 taught by Professor Delosreyes during the Spring '10 term at N.C. State.

Ask a homework question - tutors are online