Small particles in distribution systems—The effect of improving treatment

Abstract

Particles originating in water following treatment can create operational and water quality issues in distribution systems. The effect of treated water particle concentration on distribution water quality was assessed by monitoring particles at the beginning and end of four pilot distribution systems (PDSs). Flow conditions in this study produced a 75‐h retention time that included three 8‐h overnight stagnation periods. Generally, higher levels of treatment produced water of lower particle concentration, which resulted in lower particle concentrations and particle volume concentrations in the PDSs. Particles entering the PDS were almost all in the 0.5‐ to 2‐μm size fractions. Deposition and resuspension were found to be the primary mechanisms influencing particle behavior in these systems, with particles lost in systems through deposition and resuspension during flow disturbances. Study results suggest that particle monitoring should be more widely adopted as a management tool and that instruments capable of detecting smaller size fractions should be used.

Analysis of the evolution of ultra‐filtered water quality in a drinking water distribution system by particle size distribution: Influence of pre‐ozonation

“…Particles are deposited in the DWDS as a function of the water velocity, with the concentration decreasing at lower water velocity. In this regard, Byrne et al ( 2014 ) observed that the presence of particles in DWDS with a water velocity between 0.0141 and 0.0031 m/s depends on the input of particles into the system. However, in the present study, the concentration of particles in the DWDS increased with respect to the permeate during both stages.…”

“…Particle size distribution (PSD), which is closely related to the presence of particulate matter, is commonly used for the characterization of water when its quality is high (Byrne et al, 2014 ; Ceronio & Haarhoff, 2005 ). The PSD provides information about the absolute count of the various size ranges of particles present in water that is adequate to describe sudden changes in quality, mainly when membrane processes are applied (Guo et al, 2010 ).…”

“…Analyses of PSD in DWDS can be an important tool for water quality determination since they advise about aesthetic quality, problems derived from microbiological growth or chemical transformations (Byrne et al, 2014 ). Particles in the water of the DWDS have different origins, such as the treatment plant or through direct contribution, re‐suspension, or detachment of particles from the pipeline walls or biofilm, so PSD could be useful for assessing the quality of the water and its temporal evolution (Verberk et al, 2007 ).…”