Effects of Sulfate, Chloride, and Bicarbonate on Iron Stability in a PVC-U Drinking Pipe

Abstract

In order to describe iron stability in plastic pipes and to ensure the drinking water security, the influence factors and rules for iron adsorption and release were studied, dependent on the Unplasticized poly (vinyl chloride) (PVC-U) drinking pipes employed in this research. In this paper, sulfate, chloride, and bicarbonate, as well as synthesized models, were chosen to investigate the iron stability on the inner wall of PVC-U drinking pipes. The existence of the three kinds of anions could significantly affect the process of iron adsorption, and a positive association was found between the level of anion concentration and the adsorption rate. However, the scaling formed on the inner surface of the pipes would be released into the water under certain conditions. The Larson Index (LI), used for a synthetic consideration of anion effects on iron stability, was selected to investigate the iron release under multi-factor conditions. Moreover, a well fitted linear model was established to gain a better understanding of iron release under multi-factor conditions. The simulation results demonstrated that the linear model was better fitted than the LI model for the prediction of iron release.

The Transformation of Two-Line Ferrihydrite into Crystalline Products: Effect of pH and Media (Sulfate versus Nitrate)

“…Sulfate ion may first form outer and/or inner-sphere adsorption complexes on the surface of 2-line Fh as mentioned above (Figure ). ,, In addition, previous results indicated that sulfate may increase Fe 3+ release from already depositional iron (oxy)­hydroxide . Therefore, for the solid precipitated from sulfate media under acidic conditions, the dissolution–crystallization process was favored and goethite formed as the final product under these experimental conditions.…”

“…20,32,39 In addition, previous results indicated that sulfate may increase Fe 3+ release from already depositional iron (oxy)hydroxide. 40 Therefore, for the solid precipitated from sulfate media under acidic conditions, the dissolution−crystallization process was favored and goethite formed as the final product under these experimental conditions. The data obtained here demonstrate that sulfate can indeed exert some influence on the crystallization process of Fh.…”

Study on the Adsorption Relationship between Organic Matter and Particulate Matter in Water Distribution Pipes

“…The rapid development of industry and agriculture has increased the standard of living, but has also brought more toxic substances into the water supply, constantly expanding and intensifying the scope of water pollution [12]. Research on secondary pollution in drinking water and water transportation processes must consider particulate organic matter (POM) in water [13][14][15][16][17]. A multi-tracer study was carried out on the impacts of Water 2023, 15, 859 2 of 9 reservoirs on the sources and transport of riverine organic carbon in the Karst area [18].…”

An Approach to Determine Risk Indices for Drinking Water–Study Investigation

“…The paradigm becomes the argument, as we wish to live-and to drink safe water-in conditions of peace and certainty, in the belief that there is no risk or effective protection against it [17]. Meanwhile, the specialist scientific literature puts a clear emphasis on the view that quantitative risk analysis and assessment methods of water supply system failure form the basis upon which to manage security of a WSS [18][19][20][21][22][23][24][25][26][27][28][29], in the context of belonging to critical infrastructure [30].Natural waters are very rarely of a composition allowing their safe use as drinking water. Almost always proper treatment is going to be essential, and the aim of the processes involved in that is to bring water up into line with specific requirements set out in the regulation on conditions to be met by drinking water and suitable for economic purposes [31][32][33][34].…”