Process Narrative - ProMinent DULCOMETER PH-501 Assembly And Operating Instructions Manual

newterra ltd.
1291 California Avenue, Brockville, ON K6V 5W3
(800) 420-4056 / www.newterra.com

5.3 Process Narrative

The wastewater treatment plant receives two streams of wastewater. The first source is
domestic wastewater, which is fed directly to the fine to remove any fibers or debris that might
damage the membranes. The second source is kitchen wastewater which is pre-treated in the
oil and grease tanks to remove oil and grease prior to being fed into the fine screens. The
combined screened wastewater is pumped to the equalization tank (TNK-301). The equalization
tank buffers variability in the influent flow rate and concentrations of influent constituents,
maintaining a consistent flow rate and wastewater strength through the MBR system.
Wastewater is then pumped from the equalization tank to the pre-anoxic tank (TNK-401) for
denitrification.
In the pre-anoxic tank screen wastewater containing organics is combined with recycled mixed
liquor from the aeration tank containing nitrates. Bacteria use some of the organics to drive the
denitrification process, converting nitrate into nitrogen gas. This process occurs in an anoxic
environment where there is minimal oxygen. As such a pump and eductors are used to mix the
tank to prevent addition of oxygen. The denitrification process is used to meet the effluent
nitrate limit, reduce oxygen requirements and to recover alkalinity, thus reducing chemical
consumption.
Mixed liquor from the anoxic tank flows by gravity to the first aerobic tank (TNK-501) followed by
the second aeration tank (TNK-502) for aerobic biological degradation of the influent
constituents (organics and ammonia). In the aerobic tanks the nitrification process converts
ammonia to nitrate in order to meet the effluent ammonia limit. This process consumes
alkalinity, so a caustic dosing pump is used to control the pH. Additionally, liquid alum is dosed
into the anoxic zone to precipitate phosphorus in order to meet the effluent phosphorus limit.
Mixed liquor flows by gravity from the second aeration tank to the post-anoxic tank (TNK-551)
for final denitrification polishing. In the post-anoxic tank there are minimal dissolved influent
organics to drive the denitrification process. As such, an external carbon source in the form of
Micro C is dosed to supplement the organics and drive the denitrification process.
newterra O&M Manual 45
© 2017 by newterra, ltd.
All rights reserved. No part of this document may be reproduced or transmitted in any form or by any means, electronic, mechanical,
photocopying, recording, or otherwise, without prior written permission of newterra ltd.