Data on corrosive water in the sources and distribution network of drinking water in north of Iran

This study aimed to determine the parameters of scaling and corrosion potential of drinking water in sources and distribution networks of water supply in two cities of north of Iran. The results of Amlash water sampels analysis in winter revealed that the average values of Langelier, Ryznar, Aggressive, Pockorius, and Larson- skold indices was −1.31, 9.73, 11.5, 9.74 and 0.24, respectively, but, in summer they were −1.51, 10.71, 11.36, 10.72 and 0.25, respectively. For Rudsar, the results of water sampels analysis in winter illustrated that the average values of Langelier, Ryznar, Aggressive, Pockorius, and Larson was −1.12, 9.69, 11.33, 9.19 and 0.16, respectively, while, in summer they were −1.05, 10.04, 11.92, 10.18 and 0.19, respectively. The beneficial of this data is showing the clear image of drinking water quality and can be useful for preventing the economical and safety problems relating to corrosion and scaling of drinking water.


a b s t r a c t
This study aimed to determine the parameters of scaling and corrosion potential of drinking water in sources and distribution networks of water supply in two cities of north of Iran. The results of Amlash water sampels analysis in winter revealed that the average values of Langelier, Ryznar, Aggressive, Pockorius, and Larson-skold indices was −1.31, 9.73, 11.5, 9.74 and 0.24, respectively, but, in summer they were −1.51, 10.71, 11.36, 10.72 and 0.25, respectively. For Rudsar, the results of water sampels analysis in winter illustrated that the average values of Langelier, Ryznar, Aggressive, Pockorius, and Larson was −1.12, 9.69, 11.33, 9.19 and 0.16, respectively, while, in summer they were −1.05, 10.04, 11.92, 10.18 and 0.19, respectively. The beneficial of this data is showing the clear image of drinking water quality and can be useful for preventing the economical and safety problems relating to corrosion and scaling of drinking water.
& The data were obtained monthly in both cold and warm season, winter and summer, and the pH and temperature measured in the place other samples after taking as standard method were stored in a dark place at 4°C temperature and transferred to laboratory under 3 hours.

Experimental features
All the above mentioned parameters were acquired and the levels of all indices were calculated.
Data accessibility All data are available within this article.

Value of the data
The data shown here can be helpful for water and wastewater companies, water resources and treatment management, and for who related with water quality engineering and management.
The materials and ingredient of pipes, fittings and valves in distribution networks solved due to corrosive water and make some health, aesthetic and economic problems. So that, the determination of corrosion and scale potential of drinking water using reliable methods is useful for preventing of these problems.
The zoning of the Langelier, Ryznar, Aggressive, Pockorius, and Larson indices was done to make a clear picture of the corrosion and scaling potential in the water resources and distribution network in these study area.

Data
The subject of safe drinking water is important topic in the world [1][2][3][4][5]. The data of this paper present the information about the saturation situation of water supply quality for both season of winter and summer. Five stability indices, Langelier, Ryznar, Aggressive, Pockorius, and Larson were calculated using especial equations which summarized in  Table 3). The data reveled that in both season of winter and summer all of the water supply of Amlash were low corrosive to extremely corrosive according to Langelier, Ryznar, Pockorius, and Larson indices, but, all of the water supply except one case of sampling point in the winter, were neutral according to Aggressive index (Table 4). In the case of Rudsar, the data reveled that in both season of winter and summer all of the water supply were low corrosive to extremely corrosive according to Langelier, Ryznar, Pockorius, and Larson indices, but, all of the water supply except one case of sampling point in the winter, and six case of sampling point in the summer were neutral according to Aggressive index (Table 5). Zoning map of five calculated indices in Amlash and Rudsar were shown in Figs. 2-6 and Figs. 7-11, respectively.

Study area description
The selected study area were Amlash (Population; 18,580) and Rudsar (Population; 93,970) county, located in Guilan, the major province in north of Iran, which shown in Fig. 1 [6]. In the both county of Amlash and Rudsar, the climate is warm and temperate and in winter, there is much more rainfall than in summer. The average annual rainfall in Amlash and Rudsar is 1162 and 1178 mm, respectively. In addition, the average annual temperature in both county is 15.8°C. Most of the water distribution network in Amlash and Rudsar are made of metal materials with the length of 97 and 400 km, respectively. Table 1 Equations and classifications of Langelier, Ryznar, Aggressive, Pockorius, and Larson-skold indices [8,9].

Index Equation Value
Water situation Low corrosive    Table 4 The condition of drinking water in view of scaling and corrosion indices in Amlash.

Table 5
The condition of drinking water in view of scaling and corrosion indices in Rudsar.

Sample collection and analytical procedures
This research was a cross-sectional study during two season of winter and summer in 2017, and each month one sample were taken from each sample point. Therefore, fifty two samples (27 in winter and 27 in summer) were taken from nine sample point of Amlash, and one hundred and fifteen samples (57 in winter and 57 in summer) were taken from nineteen sample point of Rudsar. All measurements of the above parameters were carried out according to standard methods manual [7]. The samples were obtained monthly in winter and summer, and the pH and temperature were measured in the sampling place, other samples were stored in a dark cold box (4°C) and transferred to laboratory of school of health under 3 h. Hardness parameters, alkalinity, calcium, bicarbonate and chloride were measured by titration method according to Standard Methods for the Examination of Water and Wastewater. Sulfate was measured using spectrophotometry method and total dissolved solid was measured by scaling method. Statistical analysis of the data was done using Microsoft Excel 2013 and spatial distribution of five calculated indices were done using Arc GIS.