Statistical study on distribution of multiple dissolved elements and a water quality assessment around a simulated stackable fly ash

This study reports the leaching and transport behaviors of sixteen elements in fly ash taken from coal-fired power plant stations. A total of 480 water samples were collected from 20 simulative monitoring wells at three different times. Concentrations of elements in water samples were detected to know the spatial variability of substance, contamination level and quality of groundwater around stackable fly ash. The results of the water quality index (WQI) indicate that the water around a stackable fly ash is unsuitable for drinking. Sixteen parameters (Al, As, B, Ba, Cd, Co, Cr, Cu, Fe, Mg, Mn, V, Pb, Sb, Ni and Zn) were analyzed using different multivariate statistical approaches to assess the origins of elements in groundwater around stackable fly ash, identified five factor types that accounted for 75.66% of the total variance. Based on drinking water guidelines, As, Sb, Pb, Al and Cd were the dominant contaminants in groundwater around stackable fly ash. The quality of fly ash were considered to contribute much of the Mn, V, Ba and Mg (Cd, Cr and Ni for leaching time; Sb and Pb for leaching intensity; Al and Fe for water depths; B for flow velocity). Co, Cu and Zn had natural and random origins from crustal materials and upper reaches. Cluster analysis (CA) was adopted to classify the 20 simulative monitoring wells into two groups of water pollution, high pollution and low pollution, reflecting influences from leaching solution and upper reaches activities, respectively. The results of Hazard quotient and index (HQ/HI) suggests that As, Sb, Cd, Pb, V and Cr are the largest contributors to health risks in monitoring sites around stackable fly ash.