The objectives of this special issue were to address new trends in monitoring and removing the pollutants from water by different electrochemical and biological methods, as well as modelling the process of the adsorption of these pollutants from aqueous solutions. Twenty articles were submitted, and after the peer review process, seven papers were selected for inclusion in the present special issue.
This special issue is a complex one because some of the published papers are dealing with the monitoring of water quality and the other part of the published articles cover the preparation and utilisation of cheap and environmental friendly materials for removal of different pollutants. We believe that the research papers published in this special issue highlight the important topics represented by water quality monitoring by removal of different pollutants by using cheap, cost effective, and environmental friendly adsorbents, presenting the latest advances into the field.
The article by M. Farnane et al., entitled “New sustainable biosorbent based on recycled deoiled carob seeds: Optimization of heavy metals remediation” presents the development and usage of a new and efficient bioadsorbent” is dealing with the production and testing of new bioadsorbent materials. This new adsorbent was prepared by using deoiled carob seeds, an agroindustry waste. Prepared adsorbent was used for removal of cadmium and cobalt ions from aqueous solutions in order to obtain the optimum conditions for removal of these ions. Optimal conditions for the removal of studied ions were represented by using 0.1 g of adsorbent for 1 L of solution with an initial metal concentration of 50 mg·L−1. Process optimisation was possible by using the full-factorial experimental design. It was found that the adsorption capacity of the produced adsorbent can be improved by treating carob seeds with sodium hydroxide.
The article by X. Chen et al., entitled “Atmospheric nitrogen deposition associated with the eutrophication of Taihu Lake” is presenting the results regarding the effect of excessive amount of nitrogen deposition and its contribution to water eutrophication in Taihu basin. Comparing the data with those collected in 2007, it was observed that the contribution of nitrogen deposition to Taihu Lake increased in the last period. Accordingly, this phenomenon can accelerate the eutrophication process of Taihu Lake.
The article entitled “Spatial and temporal variations of water quality of Mateur aquifer (Northeastern Tunisia): Suitability for irrigation and drinking purposes” by B. Tlili-Zrelli et al. present the spatial and temporal variations of the hydrochemical characteristics of Mateur aquifer groundwater, which represent a critical water resource in the northeast of Tunisia. The aquifer study is important due to the water quality deterioration provoked by the salinization and the augmentation of the nitrate contamination. Experimental study shows that the highest water quality was found in the northwest and southeast part of the aquifer, areas corresponding to the recharge zone. Also, the raining season have a little influence on water quality, mainly due to the dilution.
The article entitled “Assessment of the trophic status of the South Lagoon of Tunis (Tunisia, Mediterranean Sea): Geochemical and statistical approaches” by M. Abidi et al. is presenting the water quality on South Lagoon of Tunis after its restoration. This lagoon had during time severe environmental quality issues. To solve these problems, a large restoration project was conducted. During this process, the sediments were dredged, leading at an improvement of water circulation by removing the areas of water stagnation. Experimental results have shown the high level of nutrients due to the natural and anthropogenic factors. So, the lagoon remains eutrophic, presenting a poor water quality and requiring a serious intervention.
The article entitled “Removal of colored organic pollutants from wastewaters by magnetite/carbon nanocomposites: Single and binary systems” by S. G. Muntean et al. is presenting the development of a methodology for the selective removal of industrial dyes from wastewaters by using an adsorption technology based on magnetic adsorbents. Magnetic nanoparticles embedded with activated carbon matrix were tested as adsorbents for industrial dyes removal from aqueous solutions. The regeneration capacity of adsorbent materials was tested by performing seven adsorption/desorption cycles. These materials represent a viable alternative by considering the low-cost characteristics of the synthesis, higher efficiency for the magnetic separation, and higher stability and reusability.
The article entitled “Water pollution and water quality assessment of major transboundary rivers from Banat (Romania)” by A.-M. Dunca is focused on the water management on the Timiş-Bega hydrographical basin. To assess the water quality, the water quality index was computed by taking in account the maximum, minimum, and the average annual values of physical, chemical, and biological parameters. For protecting and preserving the water quality, especially of Banat transboundary rivers, it is necessary to implement adequate wastewater management, through the construction of modern and efficient waste water treatment plants.
The article entitled “Impact assessment of phosphogypsum leachate on groundwater of Sfax-Agareb (southeast of Tunisia): Using geochemical and isotopic investigation” by S. Melki and M. Gueddari reports the results of the spatiotemporal variation of the conductivity and concentrations of major elements on groundwater of Sfax-Agareb (Southeast of Tunisia), for the period October 2013 and October 2014. It was shown that contents of 18O and 2H showed that the water of the Sfax-Agareb aquifer undergoes a large-scale evaporation process originated from recent rainfall. Experimental data proved that the groundwater was deteriorated in the downstream part of the Sfax-Agareb aquifer. The study will be helpful for the proper water development and for applying the proper remediation strategies to reduce the pollution.
Conflicts of Interest
The Guest Editor and Guest Co-editors declare that there are no conflicts of interest or agreements with private companies that will prevent us working impartially in the editorial process.
Acknowledgments
The editors thank all the authors for their contributions.
Alina Barbulescu
Narcis Duteanu
Adina Negrea
Makarand M. Ghangrekar