Mekuria Deshu Mamo, Kassegne Alemnew Berhanu, Asfaw Seyoum Leta
Center for Environmental Science, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia.
Department of Chemistry, Debre Berhan University, P.O. Box 445, Debre Berhan, Ethiopia.
Heliyon. 2021 Jul 9;7(7):e07526. doi: 10.1016/j.heliyon.2021.e07526. eCollection 2021 Jul.
Little Akaki River drains residential, industrial, and agricultural irrigation areas of Addis Ababa City Administration and is exposed to point and non-point sources of pollution. The purpose of this study was to identify sources, evaluate the levels of river water pollution, and its implications for environmental and public health. Pollution indices and multivariate statistical analyses were used to determine sources and levels of the river water pollution. Trace metals concentration was determined using inductive coupled plasma optical emission and spectrophotometer (ICP-OES). The average concentrations of COD, BOD, TDS, NO-N, NH-N SO and PO ranged from 40. 33 ± 5. 13 to 425 ± 8. 00 mg/L; 12.34 ± 0.11 to 188 ± 7.07 mg/L; 48.00 ± 0.83 to 915. 57 ± 1. 27 mg/L; 1.56 ± 1.01 to 66.50 ± 6.36 mg/L; 0.15 ± 0. 08 to 42.83 ± 11.43 mg/L; 20.50 ± 10.61 to 77.50 ± 17.68 mg/L; and 0.35 ± 0.33 to 37.95 ± 0.92 mg/L, respectively. The average concentrations of Zn ranged (0.048 ± 0.037 to 0.318 ± 0.158 mg/L), Cr (0.012 ± 0.007 to 0.203 ± 0.199 mg/L), Cd (<0.014 ± 0.0007 to 0.02 ± 0.001 mg/L) and Pb (0.031 ± 0.008 to 0.124 ± 0.034 mg/L). The comprehensive water pollution index values varied from 0.84-13.32, indicating that at all sampling sites (except for sampling site S1), the river water was heavily polluted (CPI >2.01). Heavy metal pollution index values further demonstrated potential environmental and public health implications. The principal component analysis revealed a total of 88.99% variation in the dataset, mainly contributed by organic matter, nutrients, dissolved salts, and trace metals that originated from anthropogenic sources. Contamination of the river water has impaired its suitability for urban agriculture, aquaculture, livestock drinking, and recreational purposes. Thus, improving the river water quality is recommended to mitigate potential adverse effects and promote sustainable use of water resources.
小阿卡卡河流经亚的斯亚贝巴市行政区的居民区、工业区和农业灌溉区，面临点源和非点源污染。本研究的目的是确定污染源、评估河水污染水平及其对环境和公众健康的影响。采用污染指数和多元统计分析来确定河流水污染的来源和水平。使用电感耦合等离子体发射光谱仪和分光光度计（ICP-OES）测定痕量金属浓度。化学需氧量（COD）、生化需氧量（BOD）、总溶解固体（TDS）、硝酸盐氮（NO-N）、氨氮（NH-N）、硫酸根（SO）和磷酸根（PO）的平均浓度分别在40.33±5.13至425±8.00毫克/升、12.34±0.11至188±7.07毫克/升、48.00±0.83至915.57±1.27毫克/升、1.56±1.01至66.50±6.36毫克/升、0.15±0.08至42.83±11.43毫克/升、20.50±10.61至77.50±17.68毫克/升以及0.35±0.33至37.95±0.92毫克/升之间。锌（Zn）的平均浓度范围为（0.048±0.037至0.318±0.158毫克/升），铬（Cr）为（0.012±0.007至0.203±0.199毫克/升），镉（Cd）为（<0.014±0.0007至0.02±0.001毫克/升），铅（Pb）为（0.031±0.008至0.124±0.034毫克/升）。综合水污染指数值在0.84 - 13.32之间，表明在所有采样点（除采样点S1外），河水受到严重污染（综合污染指数>2.01）。重金属污染指数值进一步表明了潜在的环境和公众健康影响。主成分分析显示数据集中总变异的88.99%，主要由来自人为源的有机物、营养物质、溶解盐和痕量金属造成。河水污染已损害其用于城市农业、水产养殖、牲畜饮用和娱乐目的的适宜性。因此，建议改善河流水质以减轻潜在的不利影响并促进水资源的可持续利用。
