New data regarding the identification of critical raw materials recoverable from raw, processed and the waste mining industry materials from Romania.

Several EU initiatives focused on renewable energy, sustainable infrastructure and green transport require a sustainable supply of a wide range of raw materials. The increase in the population and, implicitly, the increasing demand for necessary resources led to accelerated degradation of the environment, a pressing issue which the contemporary world faces. The mining activities produced huge amounts of waste, which may now become a potential secondary raw materials source that offer the potential to extract critical mineral elements of current interest. This study is intended as a historical literature data processing combined with recent analyses according to modern test methods to confirm the presence of selected critical raw materials (CRMs). The aim of the work was an integrated approach to identify the presence of Ga, In, Ge, Bi, Co and Te in ore, ore concentrates, tailing ponds and ore dumps from some Romanian historical mining regions: Apuseni Mountains (5 deposits) and the northern part of the Eastern Carpathians (Baia Mare area 2 deposits and Fundu Moldovei area 1 deposit). The consulted literature data highlighted that the tailing ponds and dumps from Romania contain a noticeable quantity of secondary resources of critical elements, respectively, an average of 2172 mg/kg Bi, 1737 mg/kg Co, 691 mg/kg Ga, 667 mg/kg In, 74 mg/kg Ge and 108 mg/kg Te in ore and 1331 mg/kg Ga, 1093 mg/kg Co, 180 mg/kg Bi, 72 mg/kg In and 35 mg/kg Ge in tailings. The overall statistics for the 2008-2018 period show a decrease in the amount of hazardous waste produced by the extractive industry in Romania. The older literature data (from about 50 years ago) for the investigated deposits was confirmed by the laboratory analysis of selected CRMs from several samples collected from known former and current mining activities. Furthermore, the optical microscopy investigations coupled with modern electronic microscopy and quantitative and semi-quantitative techniques have provided further details regarding the sample nature and constituents. High levels of Bi (35,490 mg/kg) and Sb (15,930 mg/kg) were determined in samples from Baița Bihor and Coranda-Hondol ore deposits (Apuseni Mountains), and the presence of some rare elements such as Te was also detected. The recovery of critical elements present in the mining waste significantly contributes to the transition to a circular economy that is essential for the development of a sustainable and resource-efficient economy. This study enables future research focused on the recovery of critical elements present in the mining waste, with benefits for the environment, economy and society.

Overall assessment of surface water quality in the Lower Danube River.

Water is an important receptor of environmental problems generated by anthropogenic activities, the water quality being affected by their magnitude and impact as well as by climate change. Given the international and cross-border nature of the Danube River and being aware that the pollution risk assessment is one of the key elements of the ecology and health of the people in its region, this paper assessed the state of water quality in the Lower Danube River in accordance with Water Framework Directive (Directive 2000/60/EC). The intensive monitoring program applied by the National Institute for Research and Development in Environmental Protection (INCDPM) took place during the period 2011-2017, in which approximately 1500 samples were taken and processed from 10 monitoring sites and the quality indicators stipulated in M.O. 161/2006 were analysed according to the standards in force. In this monitoring area (km 375-km 175), hydrotechnical works have been done in order to improve navigation conditions. Therefore, on the basis of the data obtained from the monitoring campaigns, multivariate statistical methods of water quality assessment were applied on the complex set of data, and at the same time, the multiparametric quality index (ICPM) was applied, an index of global comparative assessment of water quality over historical trends, developed by INCDPM. Following the evaluation of the results, the water quality in the Lower Danube River was characterized as moderately polluted and corresponds to Class III of surface water quality. The ecosystem approach indicates that the values of the monitored indicators did not correspond to the target values according to the Water Framework Directive.