The chemistry of rainwater would be altered affecting ecosystems including humans, due to the dissolved pollutants released mainly by anthropogenic sources. As industrial activities are steadily increased over time, the chemistry of rainwater is continuously changing. As such, it is vital to monitor the rainwater quality to predict future risks so that protective measures can be taken. In this context, this study aimed to investigate chemical characteristics of bulk precipitation in selected areas in Kandy and Kurunegala districts representing urban and semi-urban areas, namely, Kandy city, University of Peradeniya (UOP) and a suburb area of Kurunegala (Mallawapitiya) over a period of six months from May 2023 to November 2023, collecting samples on a weekly basis. A total of 75 samples were analyzed once a week for rainwater quality parameters using standard procedures. The results revealed that the Kandy, UOP and Kurunegala sites had 32%, 20% and 28% dry precipitation, respectively, although 12% of acidic precipitation was recorded in Kandy, and no acidic precipitation was recorded at the sites of UOP and Kurunegala. The volume weighted mean (VWM) total hardness values of the three sites were 5.91 mg CaCO3 L− 1 (Kandy), 3.90 mg CaCO3 L− 1 (UOP) and 4.54 mg CaCO3 L− 1 (Kurunegala), respectively, confirming the soft nature of rainwater sampled. The VWM concentrations of major anions of the Kandy site were in the order of SO42− < NO3− < Cl− while the other two sites had the order, NO3− < SO42− < Cl−. The VWM concentrations of trace metals varied in the order of Pb < Cu < Mn < Fe < Zn < Al in both Kandy and UOP sites, while in Kurunegala they varied as Pb < Mn < Cu < Fe < Zn < Al. Pearson correlation analysis showed that all three sites exhibited a very strong positive correlation between conductivity and TDS. A very strong positive correlation was shown between [Cl−] and [SO42−] in Kandy and Kurunegala. The UOP and Kurunegala sites showed a very strong positive correlation between [Al] and [Fe]. Probable sources of these pollutants include vehicular emissions, crustal origin, biomass burning, industries, and agricultural activities.

Determination of rainwater quality in selected geographical areas in Kandy and Kurunegala districts

期刊论文
发表日期：

2025年3月28日

查看全文

Hasini Karunarathna,
Namal Priyantha

摘要

The chemistry of rainwater would be altered affecting ecosystems including humans, due to the dissolved pollutants released mainly by anthropogenic sources. As industrial activities are steadily increased over time, the chemistry of rainwater is continuously changing. As such, it is vital to monitor the rainwater quality to predict future risks so that protective measures can be taken. In this context, this study aimed to investigate chemical characteristics of bulk precipitation in selected areas in Kandy and Kurunegala districts representing urban and semi-urban areas, namely, Kandy city, University of Peradeniya (UOP) and a suburb area of Kurunegala (Mallawapitiya) over a period of six months from May 2023 to November 2023, collecting samples on a weekly basis. A total of 75 samples were analyzed once a week for rainwater quality parameters using standard procedures. The results revealed that the Kandy, UOP and Kurunegala sites had 32%, 20% and 28% dry precipitation, respectively, although 12% of acidic precipitation was recorded in Kandy, and no acidic precipitation was recorded at the sites of UOP and Kurunegala. The volume weighted mean (VWM) total hardness values of the three sites were 5.91 mg CaCO₃ L^− 1 (Kandy), 3.90 mg CaCO₃ L^− 1 (UOP) and 4.54 mg CaCO₃ L^− 1 (Kurunegala), respectively, confirming the soft nature of rainwater sampled. The VWM concentrations of major anions of the Kandy site were in the order of SO₄²⁻ < NO₃⁻ < Cl⁻ while the other two sites had the order, NO₃⁻ < SO₄²⁻ < Cl⁻. The VWM concentrations of trace metals varied in the order of Pb < Cu < Mn < Fe < Zn < Al in both Kandy and UOP sites, while in Kurunegala they varied as Pb < Mn < Cu < Fe < Zn < Al. Pearson correlation analysis showed that all three sites exhibited a very strong positive correlation between conductivity and TDS. A very strong positive correlation was shown between [Cl⁻] and [SO₄²⁻] in Kandy and Kurunegala. The UOP and Kurunegala sites showed a very strong positive correlation between [Al] and [Fe]. Probable sources of these pollutants include vehicular emissions, crustal origin, biomass burning, industries, and agricultural activities.