A method for treating a sludge to be fed to a bioreactor for treating wastewater, or an anaerobic or aerobic sludge digester, the method comprising contacting the sludge with free nitrous acid. The antenna system includes a first and a second main reflector 304, 306, each having a shaped surface of revolution about a common boresight axis of the antenna. The spectroscopic measurements may be processed and analyzed to determine the composition of the conduit contents. The Web interface comprises a dashboard indicating an expected status and an actual status of each task.