Global NEST Journal

At this study, electrochemical oxidation of cefaclor antibiotic was investigated with new generation Sn/Sb/Ni-Ti anodes. Platinized titanium was used as cathode material. Chemical oxygen demand (COD), total organic carbon (TOC) and cefaclor (CEF) active substance parameters were used to evaluate the process efficiency. Salt (KCl) addition (mg L-1), pH value, current density (mA cm-2) and reaction time (minute) were the factors controlling the reactions. Kinetic evaluations were performed during the application of electrochemical oxidation processes to obtain pseudo-first degree kinetics. 750 mg L-1 KCl, pH 7 and 50 mA cm-2 current density were found as the optimum conditions at room temperature (25 °C). Thus, ≤ % 99 removal efficiencies were found for COD and TOC parameters after 60 min reaction and complete mineralization of CEF was occured in just 30 min at the optimum conditions. Consequently, Sn/Sb/Ni-Ti anodes were found very useful and successful for cefaclor oxidation and mineralization. The advantages of the processes are, complete mineralization at shorter reaction time with low current densities and there is no need to pH arrangement.

The aim of this study is to determine the shrub species which can be used as the biomonitor of air pollution originating mainly from the traffic and could provide the opportunity to increase the air quality in urban areas. To this end, Berberis thunbergii, Buxus sempervirens, Juniperus horizontalis, and Platycladus orientalis, mostly preferred species for roadside plantations, were chosen for the study. First, three regions with heavy traffic intensities were determined. Next, the levels of 4 heavy metals were examined by using Inductively Coupled Plasma–Optical Emission Spectrometry. The results obtained indicate that since the deposition of Cu and Zn is more in the leaves and barks of four species, these shrub species are more effective in the accumulation of Cu and Zn. Furthermore, the results of the study show that Platycladus orientalis is more effective in Cu and Pb accumulation, while Buxus sempervirens is more effective in terms of Ni and Zn accumulation. Determining high levels of traffic-originated heavy metals of Cu, Pb and Zn, particularly in the leaves of Platycladus orientalis in the city center indicates that air pollution is more intense in the city center and that Platycladus orientalis can be used as a biomonitor for traffic-originated air pollution.

Oil spill cleanup is a complex and expensive activity. There are several commonly used techniques available today. The paper suggests criteria for the selection of the best available technique that could be employed in case of oil spills in the Mediterranean Sea under specific circumstances, i.e. calm sea and presence of marine protected areas, in order to prevent pollution. Not all the available techniques could be considered. Only three of them could be selected, as these allow the preservation of natural areas, as well as the protection of threatened species and their habitats. The Analytic Hierarchy Process method has been preferred among the great variety in multi-criteria decision making tools for the selection of the best available technique. This is a widespread decision support tool suitable for the selection of the best alternative solution to a particular problem. Twenty professionals with different expertise evaluated, through pair-wise comparisons, the alternative options to choose in a protected area. The selected emergency cleanup technique must be readily available and operational in a short time. The results give a preference to new sorbents, followed closely by the magnetic nanocomposites technique.

One of the major challenges faced by researchers is to recycle industrial wastes in a manner that reduces their environmental impact in nature. An experimental study was carried out to determine the suitability of using chopped tire rubber as reinforcements in green and sustainable geopolymer concrete, with the purpose of using them as nonstructural products. The geopolymer mixture was made by mixing of fly ash powder, fine aggregate, and Superplasticizer in Na2SiO3/NaOH solution. Mixtures were divided into four different groups, with constant water to fly ash ratio of 0.12 and alkaline dosage of 45% by weight of fly ash, based on the recycled chopped tire rubber (CTR) content: 0, 10, 20, and 30% by volume of fine aggregate with two maximum sizes (2 and 4mm). Hardened properties of resulted geopolymer like compressive strength, density; and ultrasonic pulse velocity were examined at 28d. Besides that, X-Ray diffractometer and Scanning Electron Microscope were used in order to observe the microstructure of the resulted geopolymer concrete. In view of the consequences for this study, it is preferable to replace no more than 10% of fine aggregate in geopolymer concrete by CTR. In addition, according to SEM photographs, increasing the CTR content more voids will be pronounced and thus, decreasing the mechanical performance.