Occurrence of trace inorganic contaminants in drinking water distribution systems

Abstract

Many trace inorganic contaminants (e.g., lead, arsenic, nickel, vanadium, uranium) can accumulate on the surface of or be occluded within corrosion scales formed in drinking water distribution systems (DWDSs). However, few data are available on the actual concentrations of these contaminants beyond system entry points. An investigation was conducted to determine the occurrence levels and patterns of 11 trace inorganic contaminants in DWDSs. Among the trace inorganic contaminants that were found in practically all studied samples of intact corrosion scales and solids mobilized during hydrant flushing, barium was the most concentrated on a mass basis, followed by, in decreasing order, lead, nickel, vanadium, arsenic, chromium, uranium, cadmium, antimony, selenium, and thallium.

Morphological and physicochemical characteristics of iron corrosion scales formed under different water source histories in a drinking water distribution system

“…S6). According to Peng et al, As, V, U released from mineral deposits dissolution tend to be more prevalent in groundwater because these elements are relatively more abundant in ground waters and they cannot be efficiently removed by traditional groundwater treatment plants (Peng et al, 2012). Some elements concentrations in scale samples were well correlated (Table S2).…”

“…Other non-iron elements could be classified into 3 levels: Level I (accounted for 2.45e0.1%) included in the order of w a t e r r e s e a r c h 4 6 ( 2 0 1 2 ) 5 4 2 3 e5 4 3 3 gave a detailed report about the common major elements and major inorganic contaminants in solid samples (Peng et al, 2010(Peng et al, , 2012. The findings in this work were based on pipe scale samples collected from Beijing DWDS and exhibited many differences from Peng's work.…”

“…To better understand the mechanisms triggering the emergence of red water and develop suitable plans for source water switch, it is very imperative to investigate the physicochemical characteristics and performances of corrosion scales formed under different water quality conditions. Numerous studies have been dedicated to understand the iron corrosion scale properties (Tuovinen et al, 1980;Benjamin et al, 1996;Lin et al, 2001;Sarin et al, 2001Sarin et al, , 2004aGerke et al, 2008;Peng et al, 2010Peng et al, , 2012Swietlik et al, 2012); however, to our knowledge, no research work had focused on the characterization of corrosion scales with different source water histories. Several researchers have described the detailed morphologies of some iron corrosion scales and the classical multilayered structure of tubercles was demonstrated (Sarin et al, 2004b;Gerke et al, 2008).…”

“…Corrosion scales formed by the accumulation of corrosion products could serve as the breeding ground for microbes and sinks for heavy metals or other contaminants (e.g., arsenic, vanadium, lead) (Peng et al, 2010(Peng et al, , 2012Sarin et al, 2001;Tuovinen and Hsu, 1982;Tuovinen et al, 1980). Inorganic contaminants presented only at trace levels in finished waters tend to accumulate in DWDS corrosion solids where their concentration can exceed those in solution by several orders of magnitude (Peng et al, 2010(Peng et al, , 2012. Disturbance of corrosion scales or biofilms caused by water quality changes might result in discolored water episodes, microbial film loosening and sorbed contaminants release.…”

Kinetics and Mechanisms of Cr(VI) Formation via the Oxidation of Cr(III) Solid Phases by Chlorine in Drinking Water

“…19,33,36 Studies also show that chromium is one of the most abundant inorganic contaminants accumulated in drinking-water distribution systems. 37,38 The ultimate occurrence of Cr(VI) in tap water is controlled by the complex chromium redox chemistry from the source water to the water distribution system; however, current Cr(VI) control strategies mainly target upstream treatment processes. To develop effective strategies to minimize Cr(VI) in tap water, it is important to understand chromium redox chemistry in the presence of disinfectants, 39 especially in water distribution systems.…”