Particle Counting in Real-World Water Treatment Plant Operations

摘要

In the summer and fall of 1996 the Cobb County-Marietta Water Authorityrn(CCMWA) installed 40 on-line particle counter sensors at its three surface waterrntreatment plants. Particle counters were installed on each individual filter effluentrn(conventional dual media filters) as well as the raw, settled, and combined filteredrnprocess flow streams. This paper reviews the data being generated by theserninstruments and presents selected findings from the data that demonstrate waysrnin which particle count data can be used in "real-world" plant operations. Thernparticle counters have been useful in identifying both process and equipmentrnproblems.rnAs with any new process monitoring instrument, it has taken several months tornhave confidence in the new particle counters and the data they generate. As manyrnwater utilities have reported, CCMWA has also found that particle counters canrnbe a much more sensitive process monitoring instrument than turbidimeters,rnespecially for filtered water.rnThis paper presents actual data showing filter breakthrough of particles hoursrnbefore the turbidity changes, but also presents data showing how coagulationrnproblems in the plant can cause filtered turbidity to change in a more dramaticrnway than particle counts. These data emphasize that particle counters andrnturbidimeters are complementary process monitoring tools. CCMWA's particlerncounter software acts as a "mini SCADA system", collecting filter effluentrnturbidity, flow rate, and head loss data also for each individual filter (where thernsignals are available). This data is shown together, demonstrating how particlerncount data can be added to give a complete picture of the performance of anrnindividual filter as changes occur in other process parameters, such as plant flow