Effects of Starch Sources and Supplementary Materials on Starch Based Foam Trays

Firstly, foam trays were produced from glyoxal cross-linked wheat, potato and corn starches and their mixtures. The most suitable starch type for starch-based foam tray production was selected according to the level of water absorption, density, surface and cross-section micrographs of the foam trays. It was decided that a wheat and potato starch blend was the most suitable starch source for producing the foam trays because they have the lowest water absorption percentage (25.5 ± 0.7%), low density (0.17 ± 0.01 g/cm³) and a smooth surface. Potato–wheat starch foam trays with fibres were produced by adding wheat and wood fibres. Unlike wood fibres addition, wheat fibres significantly decreased the percentage of water absorption (16.63 ± 1.2%) and density (0.115 ± 0.013 g/cm³) of the tray. Also, the trays including wheat fibre had a lighter colour than the wheat–potato starch tray. To further reduce water absorption of the tray, the trays were made by adding two different types of lipids (beeswax or shortening and three different types of filler materials—kaolin, montmorillonite or zinc oxide nanoparticles). According to the level of water absorption of the trays, it was decided that shortening and zinc oxide nanoparticles, in addition to kaolin, were respectively the most suitable lipid and filler materials. The foam trays were produced by adding these supplementary materials. The addition of shortening slightly, zinc oxide nanoparticles moderately and kaolin greatly increased the density of the wheat potato starch tray including fibre. However, the percent of water absorption of the trays containing wheat fibre + shortening or wheat fibre + shortening + zinc oxide nanoparticles decreased 6.4 ± 0.01 and 5.9 ± 0.3%, respectively.     

Modeling wastewater discharge at the planning stage of a marine outfall system

The possibility of marine discharge of a negatively buoyant industrial waste was evaluated by a modeling study using Killworth 3-D, which is the first version of the Modular Ocean Model (MOM). The Model was run with the recorded wind direction and speed on the cruise dates and the circulation patterns for surface and subsurface were found to be similar with the current meter measurements. Model scenarios have been set-up in order to estimate the intensity and direction of the currents in the Nemrut Bay under the condition of wind blowing from a definite direction for a long time. MOM model has been run for four major wind directions, each having duration of 10 days and the behavior of the discharge plume in the worst case has been traced. Also, the behavior of the discharge plume in the real case has been estimated by using the wind data of the region. According to the model results, impact of trace elements that compose the discharge effluent is limited both in time and space. It is concluded that trace elements will leave the Bay in a short time due to the short residence times.     

Trace metal distribution in different chemical fractions of marine sediments along the eastern Aegean shelf

The major objective of this study was to carry out sequential chemical extraction for the partitioning of particulate trace metals in sediment samples, collected along the eastern Aegean shelf during cruises July‐August 1994, in the framework of a National Marine Measurement and Monitoring Programme for the Aegean Sea.

Five metals, Cd, Pb, Cu, Zn and Cr were examined in each of sediment samples. Three chemical fractions of the sediments were separated and concentrations of the trace metals were determined by AAS techniques. The three different leaches used were hydroxylamine hydrochloride‐acetic acid, hydrogen peroxide and nitric‐perchloric acids.

Metals were concentrated mainly in the fraction extracted by nitric‐perchloric acids. Lead in the first fraction were found in the sediments of Northern part of Aegean, where the concentration of organic material was high.

The total concentrations of Cd, Cu, Zn, Cr were higher in Izmir Bay than the other sampling points. The distribution of Pb concentrations was the highest in Edremit Bay and Izmir Bay.     

Polycyclic aromatic hydrocarbons in red mullet (Mullus bavbatus) and sediments from the Eastern Aegean Sea

The distribution of polycyclic aromatic hydrocarbons (PAHs) was investigated in red mullet (Mullus barbatus) and sediment samples in the eastern Aegean Sea. The data were collected during cruises in July and November 1994, in the framework of National Marine Measurement and Monitoring Programme in the Aegean Sea. PAHs were detected in the tissue of Mullus barbatus of different sex and size from nine sampling sites throughout the study area ranging from 0.03 to 0.46 ug/g (fresh weight). The observations show the high levels of PAHs were found in tissues of females. The average concentration of PAHs in Aegean Sea sediments ranged from 0.20 to 1.8 ug/g (dry weight). No significant correlation was observed between PAH and sedimentary organic carbon.     

Use of boron waste as an additive in red bricks

In boron mining and processing operations, large amounts of clay containing tailings have to be discarded. Being rich in boron, the tailings do not only cause economical loss but also pose serious environmental problems. Large areas have to be allocated for waste disposal. In order to alleviate this problem, the possibility of using clayey tailings from a borax concentrator in red brick manufacturing was investigated. Up to 30% by weight tailings addition was found to improve the brick quality.