This study investigates mercury, lead, copper, and zinc concentrations in six most frequently consumed fish species (120 samples), sediments (20 samples) taken from Karaduvar Fishing Area where fish species live, and Mersin Port as a contrary region, and human scalp hair for people regularly consuming these fish species (50 samples) and non-fish-eaters (15 samples) in Mersin, Turkey. On taking living environment into account, the fish groups include pelagic species of Liza saliens, Liza aurata, and demersal species of Merluccius merluccius, Mullus barbatus, Upeneus moluccensis, and Solea solea. Total Hg (THg) was found to accumulate in muscle tissues at the lowest concentration (0.01 microg/g) in L. saliens and at the highest (2.66 microg/g) in S. solea. Pb was only detected at high concentrations of 1.86 microg/g in M. barbatus and of 2.16 microg/g in M. merluccius. Cu and Zn concentrations were below the detection limit within all fish species. In the sediment samples, Pb and Cu concentrations were persistently below their effect range-median (ERM) value, whereas this limiting value only maintained for 15% of THg concentrations. On the other hand, the effect range-low (ERL) of sediment exceeded at Pb in 15% of samples and Cu in 25% of samples. Zn remained below the detection limit for sediment samples. The metal concentrations at scalp hairs of regular consumers of these fish groups and non-fish eaters vary from the range 0.40-3.28 to 0.14-1.02 microg/g for THg, 11.16-107.84 to 8.00-22.38 microg/g for Pb, and 151.67-645.35 to 144.92-343.50 microg/g for Zn. An important finding of the present study is the significant adverse impact of sedimentary heavy metal bioaccumulation to human through the consumption of demersal fishes in the city of Mersin along the southern coast of Turkey.

Ecological Port, also known as Green Port (EcoPort), is an important development strategy protecting marine aquatic life and ecosystem. It provides business information on environmentally best practices and corporate responsibility centred around marine ports and terminals, including shipping, transport and logistics. Green Port concept gives a great opportunity to make transportation clean and efficient. Marine industry should adopt new legislations to create a clean future. It is the key point to implement strict liquid and solid waste policies and to begin to use low sulphur fuel and electric power whenever possible. Green Ports utilize electric powered cranes and they have strict garbage policies and well-educated personnel. Furthermore, the vessels entering Green Ports must have an accreditated waste management and bunkering plan. In this study, the implementation of the Green Port concept at some selected Turkish, European and the US Ports was given and a simple Green Port Model was prepared.

Nowadays, one very dynamic development of 3D printing technology is required in the construction industry. However, the full implementation of this technology requires the optimization of the entire process, starting from the design of printing ideas, and ending with the development and implementation of new materials. The article presents, for the first time, the development of hybrid materials based on a geopolymer or ordinary Portland cement matrix that can be used for various 3D concrete-printing methods. Raw materials used in the research were defined by particle size distribution, specific surface area, morphology by scanning electron microscopy, X-ray diffraction, thermal analysis, radioactivity tests, X-ray fluorescence, Fourier transform infrared spectroscopy and leaching. The geopolymers, concrete, and hybrid samples were described according to compressive strength, flexural strength, and abrasion resistance. The study also evaluates the influence of the liquid-to-solid ratio on the properties of geopolymers, based on fly ash (FA) and metakaolin (MK). Printing tests of the analyzed mixtures were also carried out and their suitability for various applications related to 3D printing technology was assessed. Geopolymers and hybrids based on a geopolymer matrix with the addition of 5% cement resulted in the final materials behaving similarly to a non-Newtonian fluid. Without additional treatments, this type of material can be successfully used to fill the molds. The hybrid materials based on cement with a 5% addition of geopolymer, based on both FA and MK, enabled precise detail printing.

This study aimed to determine the effects of design parameters, including the liquid/solid ratio (L/S), Na2SiO3/NaOH weight ratio, and curing temperature, on class F fly ash-based geopolymer composites. For this purpose, two disparate sources of fly ash were supplied from Çatalağzı (FA) and İsken Sugözü (FB) Thermal Power Plants in Turkey. Two different L/S ratios of 0.2 and 0.4 were used. The Na2SiO3/NaOH ratios in the alkaline solutions were 1, 1.5, 2, 2.5, and 3 by weight for each type of geopolymer mixture. Then, 40 different mixes were cured at two specific temperatures (70 °C and 100 °C) for 24 h and then preserved at room temperature until testing. Thereafter, the physical water absorption properties, apparent porosity, and bulk density were examined at 28 days on the hardened mortars. Additionally, compressive and flexural tests were applied to the geopolymers at 7, 28, and 90 days. It was found that the highest compressive strength was 60.1 MPa for the geopolymer manufactured with an L/S of 0.2 and Na2SiO3/NaOH ratio of 2. Moreover, the best thermal curing temperature for obtaining optimal strength characteristics was 100 °C for the FB.

Alkali activated cement (AAC) can be manufactured from industrial by-products to achieve goals of “zero-waste” production. We discuss in detail the AAC production process from (waste) post-production clay, which serves as the calcium-rich material. The effect of different parameters on the changes in properties of the final product, including morphology, phase formation, compressive strength, resistance to the high temperature, and long-term curing is presented. The drying and grinding of clay are required, even if both processes are energy-intensive; the reduction of particle size and the increase of specific surface area is crucial. Furthermore, calcination at 750 °C ensure approximately 20% higher compressive strength of final AAC in comparison to calcination performed at 700 °C. It resulted from the different ratio of phases: Calcite, mullite, quartz, gehlenite, and wollastonite in the final AAC. The type of activators (NaOH, NaOH:KOH mixtures, KOH) affected AAC mechanical properties, significantly. Sodium activators enabled obtaining higher values of strength. However, if KOH is required, the supplementation of initial materials with fly ash or metakaolin could improve the mechanical properties and durability of AAC, even c.a. 28%. The presented results confirm the possibility of recycling post-production clay from the Raciszyn II Jurassic limestone deposit.