Selenium, Sulphur, Trace Metal, and BTEX Levels in Soil, Water, and Lettuce from the Croatian Raša Bay Contaminated by Superhigh-Organic-Sulphur Coal

Abstract

This paper elaborates soil, water, and lettuce contamination status with respect to selenium, sulphur, trace metals, and BTEX (benzene, toluene, ethylbenzene, and xylenes) in a coal-based area (Raša Bay, Adriatic Sea, Croatia). A local coal-fired power plant polluted soil with S, Se, Cd, and PAHs due to the combustion of domestic superhigh-organic-sulphur coal. The locality is dotted with waste from coal mining/separation, coal combustion, former metal factories, untreated municipal and coal mine effluents, along with various harbour activities, which contribute to environmental contamination. The methodology involved ICP-MS and GC-MS for the measurement of trace elements and BTEX, respectively, while soil sulphur was determined with Eschka’s mixture. The max values of the analysed trace elements in soil (mg/kg) are reported: Hg 1.14, Cd 3.29, V 624, Se 10.3, Pb 872, Cr 1860, Zn 6580, Cu 1850, and U 25.2. According to ecological indices, these values fall into the category of an extremely high level of soil pollution. Elevated total Se values in surface water are ascribed to leaching of seleniferous coal, ash, and coal-polluted soil. Levels of BTEX in water samples were very low (0–0.83 µg/L). The data provide basic information on the inorganic and organic contamination status of the Raša Bay area.

Use of Bacteria and Synthetic Zeolites in Remediation of Soil and Water Polluted with Superhigh-Organic-Sulfur Raša Coal (Raša Bay, North Adriatic, Croatia)

“…Soil and SHOS Raša coal sampling campaigns ( Figure 1) were conducted on several occasions during the period 2013-2015 [4,20,28]. Soil samples were collected at: S2, a former small-scale coal-fired power plant Vlaška; S4, and S8, CCW locality in Štrmac village; S6, sampled close to a beach in the Trget village; S9, a former coal-mining town Krapan; S14, a former rail line (red-colored line in Figure 1), between the Raša town (R.) and a coal-separation unit Štalije (Š.…”

“…); and S10, unpolluted soil [30] taken from a site 10-15 km NE from the study area. A summary of soil samples' (2 kg per sample) physicochemical properties (pH, LOI-loss on ignition, CEC-cation exchange capacity, and CaCO 3 , acquired and described in previous papers [4,20,28]), along the levels of sulfur, PTEs in soil, and SHOS Raša coal, are shown in Table 1. Nonfiltered water samples (300 mL per sample) were collected from an old mining town Krapan and a city of Raša ( Figure 1) in early May 2019.…”

“…The objectives of this study were as follows: (1) To apply bioremediation tests, by using Ralstonia sp. on SHOS Raša coal, as well as few selected soil samples polluted with SHOS coal and CCW, geochemically characterized in previous papers [4,5,20], and (2) to examine the ability of synthetic zeolites to remove PTEs from Raša coalmine water and stream water affected by coal leachates and nontreated municipal wastewater on laboratory scale.…”

Geochemical Equilibrium and Processes in Seawater

“…Medunić et al [9] studied the selenium, sulfur, and trace element signature of the Raša Bay environment contaminated by superhigh-organic-sulfur coal. In the Labin city area (also situated in the northern Adriatic, Croatia), in the vicinity of the Raša Bay, historic (back to the 18th century) coal mining and associated foundry industries are located.…”

“…Each of these papers [7][8][9][10][11] provides an insight into the problem that is ubiquitous in populated areas, but with a unique viewpoint, i.e., taking into account the features of the karst background.…”