Ganga River Ecology Research Laboratory, Environmental Science Division, Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi, 221005, India.
Arch Environ Contam Toxicol. 2022 Feb;82(2):191-205. doi: 10.1007/s00244-021-00820-8. Epub 2021 Mar 23.
Excessive loading of water bodies with surface runoff-driven nutrients and heavy metals has become a serious concern worldwide. We investigated the surface runoff quality for nutrients and heavy metals being flushed to the Ganga River, as influenced by atmospheric deposition (AD). We selected three city sites in India, Haridwar, Varanasi, and Howrah, which differ widely with respect to population density and anthropogenic activities. We found distinct spatio-temporal trends in AD input of nutrients and heavy metal with values being highest in Varanasi region followed by Howrah and Haridwar. The runoff nutrients and metals showed strong synchrony with their respective levels in AD input. The concentrations were higher in the first flush. We found strong correlations (R = 0.83-0.93; p < 0.001) between AD metals and nutrients with their respective concentration in runoff. For all the studied metals, except Cd, the major proportions were in particulate form. The Cd was present in almost equal proportions in particulate and dissolved fractions. Metals in runoff were found in order as: Zn > Pb > Cu > Ni > Cr > Cd. In general, the concentrations of metals were higher than those reported in other studies. The contamination factor and geo-accumulation index show that the Cd was a major pollutant in the runoff. The pollution load index (PLI) indicates that all three sites are highly polluted. Our study indicates that there is a need to reduce particulate loads. Furthermore, because of the high concentrations of pollutants in the first flush, strategies may be developed to enhance the efficiency of treatment of the first flush of runoff.
水体中地表径流携带的营养物质和重金属的过度负荷已成为全球关注的严重问题。我们调查了恒河受到大气沉降（AD）影响的地表径流水体中营养物质和重金属的质量。我们选择了印度的三个城市站点，即哈里瓦、瓦拉纳西和豪拉，它们在人口密度和人为活动方面存在很大差异。我们发现 AD 输入的营养物质和重金属具有明显的时空趋势，其中瓦拉纳西地区的数值最高，其次是豪拉和哈里瓦。径流水体中的养分和金属与 AD 输入中的相应水平表现出很强的同步性。初期冲刷的浓度较高。我们发现 AD 金属和养分与其在径流水体中的浓度之间存在很强的相关性（R=0.83-0.93；p<0.001）。除 Cd 外，所有研究的金属中，大部分以颗粒形式存在。Cd 几乎等量地存在于颗粒和溶解部分中。径流水体中的金属顺序为：Zn>Pb>Cu>Ni>Cr>Cd。总的来说，金属浓度高于其他研究报告的浓度。污染因子和地质累积指数表明，Cd 是径流水体中的主要污染物。污染负荷指数（PLI）表明，这三个站点都受到高度污染。我们的研究表明，需要减少颗粒负荷。此外，由于初期冲刷的污染物浓度较高，可能需要制定策略来提高初期冲刷径流处理的效率。
