As many water pollution control facilities (WPCF) are now operating biological nutrient removal (BNR) processes, it is more critical to understand exactly how nutrients are being utilized within the treatment process. Traditional data collection paradigms have focused on influent and effluent water quality characterization with less emphasis on in-process monitoring. It’s as if we were able to read the first and last chapter of a book and still have a fairly good understanding of the story. However, with BNR we have added many more chapters to this book and cannot afford to skip them.
Some facilities are able to secure funding for online analytical equipment to measure nutrients (nitrogen and phosphorus) within the biological process. Still, the sheer number of sensors required to fully monitor a biological process can be daunting, both from a financial and maintenance perspective. Although online instrumentation is an excellent source of data, when it is not available my preference is for the alternate option: nutrient profiling.
A nutrient profile is a series of grab samples taken along the biological treatment process. The purpose of a nutrient profile is to gain a better understanding of how nutrients are being removed from wastewater via biological activity. Nutrient profiles can be used for optimization and process diagnostics with the help of other data, however, they do have their limitations. Grab sampling only provides a snapshot and does not necessarily capture dynamics of the treatment process. To overcome this, a series of nutrient profiles at several different time periods can be conducted. Nutrient profiles can provide meaningful information about the BNR process, but keeping in mind the limitations of grab sampling is important. Practically speaking, full-scale nutrient profiling is a complex and time consuming process that requires attention to detail, planning, and concentration. To master this art form takes some time, but there are some useful steps to follow while conducting nutrient profiles.