November 2007, Vol. 19, No.11

From the Editors

WE&T Prelude

No Place Like Home

Melissa Jackson

One morning, I was walking our Labrador, and a mammoth-size dog bounded into a busy intersection to greet us. I was able to drag her out of the street and back to the porch from which she’d jumped, but her tags showed that “Bailey” lived more than a mile away. Since no one else was around, I did what any other canine-centric person would do: secure the dog in a stranger’s yard, sprint five blocks to take my dog home, then come back with two free arms, a leash, and a cell phone.

Racing back to the house where Bailey (hopefully) was still fenced in, I was nearly out of breath, and only peripherally aware of another panicked woman heading in the same direction. She, too, had a leash in hand. As it turns out, she’d been walking her dogs a few minutes earlier, and she had the same experience — and reaction — as I did.  Two leash-wielding dog wranglers, one common motivation: This moment exemplifies why I fell in love with our neighborhood. After more than 20 years of living in a transient, major metropolitan area, I knew what it was like to feel truly at home (so did Bailey, later that day).

Socially or professionally, finding a community where you can make a difference is one of life’s great rewards. At the recently concluded WEFTEC® in San Diego, for example, it was inspiring to see such a diverse group of water professionals, at various stages of their careers, contributing to benefit the larger community. Seeing the Stockholm Junior Water Prize winners take the stage at the Opening General Session and shyly face their future colleagues in the audience, you could not help but wonder what new advancements they will lead. You could sense the enthusiasm of the speakers and exhibitors — young professionals and veterans alike — as they shared research, presented new technology, and fielded questions. And throughout WEFTEC, the technical expertise was balanced by the humanitarian and environmental concerns that drive the profession: reminders that this is a kinship not just of substance but also of heart.

In this issue we honor those individuals who have helped shape the future course of this vibrant community. Click here for coverage of the 2007 WEF Awards.

Melissa Jackson, editor

Operations Forum Editor's Note

Managing the Triple-Point Balance

Steve Spicer

Time, energy, and funding all are running in short supply nationwide. The only way to ensure enough of each is to rely on education and experience to strike the right balance. This relationship becomes very clear in the solids processing train.

A switch to a different technology might enable more efficient operation and lower power consumption, and therefore, lower costs. But those savings must be balanced against the capital expense of equipment as well as the increased staff time and lower throughput associated with getting up to speed with the equipment.

Similarly, polymer can be a large expense, but a slightly higher dose can increase the speed and effectiveness of dewatering. Faster processing enables greater throughput, which translates into less staff time. Also, solids that contain less water take up less space in trucks and landfills. But using too much polymer wastes chemicals and increases the amount of solid material going out the door.

Just working faster can save time and reduce labor costs, but taken to extremes it can increase chemical and energy demands in the solids process as well as create a liquid recycle stream that takes more energy to treat.

These situations can feel like a vicious cycle, but with the proper information that cycle can lead to a good balance of resources. The articles in this issue take a close look at solids thickening to help you find the sweet spot on this triple-point balance.

First up, a representative of one of the largest manufacturers of belt filter presses and gravity belt thickeners in the U.S. municipal market offers some tips and strategies to improve your polymer systems. The article (click here) compares polymer types, examines various polymer wetting systems, provides a tutorial on finding the right amount of mixing between polymer and sludge, and takes a final look at just what to expect from various polymers.

Then, read about how the Oxford Pollution Control Plant (London, Ontario) evaluated two systems to see which would meet the thickening needs of the expanded plant with the least amount of construction. They contrasted mechanical thickening and an innovative use of vacuum membranes for waste activated sludge (WAS) thickening. Click here for the details..

Finally, we list the winners of the 22nd Annual U.S. Environmental Protection Agency Clean Water Act Recognition Awards. These facilities have found the formula to reach their perfect balance for all of their processes. For more information on the award winners, click here.

Steve Spicer, editor