Industrial activities in the Baia Mare, Romania area have generated strong pollution, and the impact on soil quality in the neighboring areas of the city remains unclear. The aim of the research is to investigate samples of soil from Baia Mare in order to determine the quality of the soil and also the ecological risk of the soil. This study presents among the first studies using the ecological risk assessment methodology on the soil from the Baia Mare area and aims to serve as scientific support for future studies and research. Evaluation of the soil quality state was performed by determining the physical-chemical characteristics of the soil (pH, texture, structure, and concentration of metals). Evaluation of the anthropic activity from the studied areas was conducted by determining the pollution indices: C_f; C_d, PLI, Er, and PERI. The results of this study indicate that the surface soils have very high concentrations of metals (Cd: 3.5–14.4 mg kg⁻¹; Cu: 9.4–361.5 mg kg⁻¹; Pb: 29.7–1973 mg kg⁻¹), with exceedances of the limit values established in the Romanian legislation. Results regarding the degree of contamination, the PLI pollution load index (1.3–14.9), and the PERI potential ecological risk index (733.9–4686) indicate that soils in the studied area have a very high degree of pollution.

The feasibility of using Robinia pseudoacacia in phytoremediation of sterile dumps was determined. The potential of Robinia pseudoacacia seeds to grow in a medium contaminated with high concentrations of Pb, Cd, and Cu was firstly evaluated by applying germination tests on acacia seeds in the presence of various extractants prepared by mixtures of sterile material (SM) collected from the “Radeș” dump (Romania), calcium carbonate (CaCO₃) and dehydrated sludge (DS) from Someș Water Treatment Plant (Cluj Napoca, Romania), fertilizer (N.P.K.), and potassium monobasic phosphate (KH₂PO₄-99.5%). The results indicated that Robinia pseudoacacia seeds grow much better in an acidic than in a neutral medium and in the absence of carbonates. The capacity of metal uptake from SM by Robinia pseudoacacia and the development of the plants were then investigated at the laboratory scale. During the phytoremediation process, 92.31% of Cu was removed from SM, and the development of the Robinia pseudoacacia plants was favorable. However, although the results of the present study indicated that Robinia pseudoacacia can be successfully used in the phytoremediation of sterile dumps, making a sustainable decision for the current situation of sterile dumps located in mining areas may be difficult because an optimal point between people, profit, planet, and diverse ethical views must be found.

Environmental pollution has particular implications for the whole geosystem and increases the global risk to human and ecological health. In this regard, investigations were carried out on soil samples to perform the quality status assessment by determining: pH, texture, structure and metal concentration, as well as carrying out an assessment of anthropogenic activity by determining pollution indices: C_f (contamination factor), C_d (degree of contamination), PLI (pollution load index), E_r (ecological risk index) and PERI (potential ecological risk index). Analyses on soil samples showed high concentrations of metals (Cu: 113–2996 mg kg⁻¹; Pb: 665–5466 mg kg⁻¹; Cr: 40–187 mg kg⁻¹; Ni: 221–1708 mg kg⁻¹). The metal extraction experiments were carried out by bioleaching using Thiobacillusferrooxidans, microorganisms at different amounts of bioleaching solution (20 mL and 40 mL 9K medium) and a stirring time of up to 12 h. The results on the degree of contamination, pollution loading index PLI (2.03–57.23) and potential ecological risk index PERI (165–2298) indicate that the soils in the studied area have a very high degree of pollution. The decontamination procedure by bioleaching showed a decrease, but at the end of the test (12 h), the followed indices indicate high values, suggesting that bioleaching should continue. The depollution yield after 12 h of treatment is, however, encouraging: Cu 29–76%, Pb: 10–32%, Cr: 39–72% and Ni 44–68%. The use of yield–time correlation equations allows the identification of the optimal exposure time on the bioleaching extraction process to obtain optimal results. The aim of the research is to determine the soil quality, soil environmental risk, extraction of metals from polluted soils by bioleaching and to identify influencing factors in achieving high remediation yields.

Baia Mare area represents one of the most important mining areas of Romania. Although the mining activities carried out here are currently inactive (since 2012), they generated residual pollution that negatively influences all the environmental factors. The aim of the study is to evaluation of the quality of surface water from the vicinity of the city of Baia Mare, Romania. The surface water samples, collected in two distinct years (2021 and 2022), were analyzed to determine the concentration of heavy metals (Cd, Cr, Cu, Ni, Zn, Pb, Fe, Mn, and As) in order to establish the degree of contamination and the water quality through heavy metal evaluation index (HEI), heavy metal pollution index (HPI), and water quality index (WQI). The pH and the content of cations (Ca, Mg, Na, K) and anions (HCO₃⁻, SO₄²⁻, Cl⁻) were also determined for complex characterization. The results showed that the water in the area had a high degree of pollution with high concentrations of Cr: 0.165–1.57 mgL⁻¹, Ni: 0.01–0.718 mgL⁻¹, and Cu: 0.036–0.195 mgL⁻¹. The pollution indices showed an average level of heavy metal pollution for the collected surface water samples. The quality index demonstrated that all surface water samples in the study area were unfit for irrigation and drinking due to poor and very poor water quality.

In Romania, huge quantities of gangue material from the mining activity practiced in the past were improperly stored and led to the pollution of the environment. Thus, this work is framed to manage the sterile dump of the “Radeș” mine (Alba, Romania) through a 12-week phytoremediation process. The efficient use of Robinia pseudoacacia was studied through the implementation, at the laboratory level, of a phytoremediation experiment based on various variants prepared by mixtures of gangue material, uncontaminated soil, and dehydrated sludge. The prepared variants, all planted with R. pseudoacacia, were watered with tap water, potassium monobasic phosphate, and enzyme solution. The bioconcentration and translocation factors for lead showed values ˂ 1, which indicates a potential presence of an exclusion system for Pb or a reduced Pb bioavailability since the R. pseudoacacia accumulates high concentrations of metals absorbed on and inside the roots. For copper, both factors had values > 1 indicating the suitability of R. pseudoacacia to readily translocate copper into the epigean organs. In the investigated experimental conditions, the highest efficiency in the removal of copper (93.0%) and lead (66.4%) by plants was obtained when gangue material was not mixed with other materials and wetted with enzymatic solution.

This paper describes a former sterile dump site that is the result of mining and ore processing. A large site located in the Baia Mare mining area (Romania) with a significant amount of Suior-type mining concentrate deposits was selected for this research. The method of analysis used in this study is inductively coupled plasma optical emission spectrometry (ICP-OES). To characterize the contaminated area, a total of 27 sterile samples and one soil sample were collected from the studied site, which was affected by the mining activity. The samples were mineralized by a mix of hydrochloric acid and nitric acid. The disaggregation of the samples took place on a sand bath, and the concentrations of nine heavy metals were determined using an inductively coupled plasma optical emission spectrometer. The investigations provided the information for a detailed analysis allowing the assessment of trace element concentrations to establish whether the area requires remediation. This paper aims to highlight the importance of obtaining quantitative analysis data when characterizing heavy metal contaminated areas that need to undergo the remediation processes, utilizing accurate and fast systems such as modern multispectral analytical devices. The objective of this paper consists of the characterization of an area in the Baia Mare municipality, Romania, affected by high heavy metal concentrations due to sterile mining material being deposited on its surface in order to determine if the area requires remediation.