Experimental Analysis of the Hydraulic Performance of Filtering Cartridges in Drinking Water Networks

Liquid treatment processes have been assuming increasing importance in recent decades with the progressive industrialization to ensure public health security for drinking water or to prevent economic damage when safeguarding important production processes. Major investments have been devoted to the research, study, and design of innovative products that are able to respond to the demands of the market, which currently offer several solutions, among which filtration treatment still represents a major one. This work focuses, in particular, on filtration of drinking water with filter cartridges, with the aim to test their hydraulic performance and, particularly, to evaluate the head losses that they produce when introduced into a hydraulic system. The local pressure drops, in fact, may compromise hydraulic plants already characterized by low pressures. What is more, this condition is increasingly likely in supplying networks due to the coexistence of several factors, such as water losses due to failures and inefficient maintenance, severe and prolonged droughts, and increased water demand related to social and economic development. In these systems, the insertion of filtration cartridges can make the pressure levels fall below the minimum limit recommended to ensure the smooth operation of domestic devices. More in detail, in the present study the behavior of seven different commercial filter cartridges was analyzed through a set of experiments conducted in a pilot circuit at the Laboratory of Environmental and Maritime Hydraulics (LIDAM), University of Salerno. These tests have been performed in different operating conditions, collecting pressure data through various pressure gauges. The analysis proved that for common values of operating flow rates in domestic plants the pressure drops in the filter can be of the order of some meters and provided some useful information for the choice of the proper cartridge in low-pressure distribution systems.