April 2009, Vol. 21, No.4
Operations Forum Editor’s Note
A Shot of Green
April is a good time to talk about nutrient removal. For most of the country, this is when seasonal native plants begin to reappear. It’s also prime season for fertilizing pastures, fields, lawns, and gardens to get ready for the summer. With many winter–summer permits switching seasons in May, it’s also time to make sure nutrient removal systems are in good working order.
To that end, the article “Phosphorus Removal on a Small Scale” assesses three different biological phosphorus removal treatments. The article focuses on plants from three small Minnesota communities; each plant has a flow less than 2.5 mgd (9500 m3/d). Which technology bested the competition? Well, it turns out that depends on factors specific to a treatment plant’s location, resources, and needs.
On the other side of the nutrient spectrum, keeping straight the different types of nitrogen and their individual and combined effects on our waters can be difficult. Not to mention that it can be hard to pinpoint exactly when waterborne nutrients go from helpful to harmful. To that end, this month’s Extra, “Decoding Nitrogen Terminology,” provides a quick reference for nitrogen’s many forms and interactions, as well as the laboratory tests used to measure them.