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The current work focused on the water quality of the Bega and Timis rivers measured by two methods. One of them is the method by which the water was analyzed from a physical-chemical point of view, and the other aimed at quantifying the degree of water pollution by biological methods. In this sense, diatoms were used. In the study, samples of water and diatoms were taken using specific techniques from the Bega and Timis rivers, starting from near the area of their formation until near the border with Serbia. Four sampling points were chosen on the Timis River plus one sampling point on the Surgani River, which is a tributary of the Timis, and six sampling points on the Bega River. The points were chosen specifically, being located downstream of the major sources of pollution. In order to locate the points, information was collected from the studies carried out as part of an extensive monitoring that spanned several years. The abundance and diversity of diatom species were used to calculate the Biological Diatom Index (BDI) and the Saprobity Index (SI). These two indices provide valuable information about organic or heavy metal pollution of water bodies.

This paper presents the ecological state of large areas of the Bega and Timis River basins, evaluated based on physical-chemical parameters of water samples in relation to the anthropogenic sources of pollution that occur along these rivers. For the monitoring program, twelve sampling points on the Bega and ten sampling points on the Timis were established in order to determine surface water quality. The potential sources of pollution were highlighted by a downstream vs. upstream analysis. Ecological conditions have been assessed taking into account the national legislation, which transposes the Water Framework Directive on promoting the sustainable use of water based on the long-term protection of water resources. The main sources of pollution were related to the discharges from localities and industry, but the current ecological status of the two water bodies analyzed is in a relatively good state.

The aim of this study was to obtain new electrochemically modified electrodes with graphene and Au, Pt, Ag particles considering graphite (GP) and glassy carbon (GC) substrate by applying the chronoamperometry technique in order to develop the detection protocol of tetracycline (TC) considered as emerging pollutant in water, using cyclic voltammetry (CV) technique. The graphite-based substrate used for Ag/ Au/ Pt electrodeposition led to the electrode compositions on which TC oxidation process was not diffusion-controlled and as consequence, TC detection failed. TC detection protocols were developed for all Ag/Au /Pt electrodeposited GC and GC-GP electrodes. Better limits of TC detection was achieved for Ag electrodeposited on GC-GP at the cathodic potential of 0.460 V/SCE.

The sludge management resulting from the urban wastewater treatment plants, from the point of view of circular economy, follows its using as a fertilizer for agricultural lands, degraded lands, in horticulture and forestry. The aim of this paper is the proposing of an alternative way of using the sludge resulting from urban wastewater treatment plants in a sustainable way with a low impact on the environment. The experimental results showed the efficiency of using the stabilized sludge as fertilizer for naturally and anthropically degraded lands and cultivated with Salix sp. The use of stabilized sludge determined the improvement of the nutritional characteristics of the degraded lands, which allowed the growth, development and maintenance of the culture of Salix sp. Considering the characteristics of the cultures and the quantities of metals accumulated by Salix sp., it can be concluded that it has adapted to the environmental and the substrate conditions from the studied degraded lands. The results obtained on the two degraded lands indicate that Salix sp. can be used for its introduction in the economic circuit, both of the salty soils and of the slag and ash deposits.

A new electrochemical sensor designed by modifying the commercial boron-doped diamond (BDD) electrode with graphene oxide (GO) reduced electrochemically and further electrodecorated with silver (Ag), named the Ag/GO/BDD electrode, was selected among a series of the BDD, GOelectroreduced onto BDD (GO/BDD) and silver electrodeposited onto BDD (Ag/BDD) electrodes for the detection of tetracycline (TC) in aqueous solution. The best results regarding the sensitivity of 46.6 µA·µM−1·cm−2 and the lowest limit of detection of 5 nM was achieved using square-wave voltammetry (SWV) operated at the step potential of 5 mV, modulation amplitude of 200 mV and the frequency of 10 Hz in alkaline medium. The application of the alkaline supporting electrolyte-based procedure is limited for water monitoring due to the presence of chloride that interferes with TC detection; however, it can be applied for quantitative determination of pharmaceutical formulations. 0.1 M Na2SO4 supporting electrolyte eliminated chloride interference and can be used for the application of Ag/GO/BDD in practical detection of TC in water.