Wastewater Treatment

Biodégradation in wastewater treatment plans is of environmental importance, because we need to know how much the concentration of organic matter is reduced by the treatment. In this context, it is often used to indicate the percentage of the theoretical oxygen demand (ThOD), which is the amount of oxygen used by a complete oxidation. BOD is an abbreviation for biological oxygen demand. It is often used with indication of the considered time, for instance, BOD5, which is the biological oxygen demand for period of 5 days. BOD5 is often used to indicate the concentration of organic matter, because the environmental interest in water is the oxygen depletion for a reasonable period. Five days was chosen, when BOD was introduced in UK more than hundred years ago, because all British rivers reach the sea within 5 days. The stoichiometric equation organic matter + oxygen = carbon dioxide + water shows that for typical municipal wastewater, 1 g of organic matter will require approximately 1.4 g of oxygen. The usual biodegradation rate, k, for the organic matter in municipal wastewater, which is relatively readily biodegraded, is 0.35 1/24h. It means that if we indicate the loading of organic matter expressed by oxygen demand by L, we have

If BOD5 is for instance 150 mgl_1, Lo is 181 mgl _1. Notice that L0 = BODinfinite = ThOD.

Was this article helpful?

0 0
Trash To Cash

Trash To Cash

This book will surely change your life due to the fact that after reading this book and following through with the steps that are laid out for you in a clear and concise form you will be earning as much as several thousand extra dollars a month,  as you can see by the cover of the book we will be discussing how you can make cash for what is considered trash by many people, these are items that have value to many people that can be sold and help people who need these items most.

Get My Free Ebook


Post a comment