Issue 4

The slag generated in the rotary furnaces is classified hazardous waste. In this regard, landfill disposal of lead smelting slag is not feasible since a few hundred tons are produced per year; leaching of heavy metals into ground water is of concern. The release of heavy metals into the environment has resulted in a number of environmental problems. The disposal of slag is becoming more expensive each year due to large land areas needed for its disposal. The best way to solve the disposal problem of waste materials is to decrease the quantity for disposal with utilization of waste materials in the industry. The toxicity of the waste is determined by leaching tests and depending on the characteristics of the waste the spent abrasive must be disposed of as solid or hazardous waste. The aim of this study is to investigate leaching characteristics of lead smelting slag according to leaching tests such as TCLP, and TS EN 12457-4 tests methods. In this study, mixed-level factorial design was applied to optimize process parameters for lead removal from lead smelting slag using natural (sepiolite, montmorillonite, illite and seashell) and waste material (red mud). The established model was then used as a predictor to achieve better understanding of the adsorption process and to obtain optimal settings of the experimental factors. The present study includes the safe disposal of lead smelting slag using natural and waste materials. Experimental results indicated that red mud and seashell can be used as environmentally friendly adsorbents that are capable of lead release from lead smelting slag.

The purpose of the study was to improve drinking water quality of conventional treatment processes by combining with UF-membrane systems. Performances of two membrane systems were evaluated in two different full-scale conventional water treatment plants in Istanbul. Low-pressure UF membranes were combined after settling and filtration units of Büyükçekmece and Emirli water treatment plants. Low-pressure UF systems were operated under vacuum and pressure conditions. The experimental results indicated that combining UF systems enhanced drinking water quality with respect to turbidity, TOC and UV254 removal. In all cases, vacuum-driven UF membranes provided higher treatment performance and low energy consumption comparing to pressure-driven system. Combination with UF membranes also reduced disinfection by-products.

This study was conducted to investigate the recycling of rural wastes employing vermicomposting technology by Eisenia fetida. Three medium including kitchen waste, rotting foliage and cow dung were performed in 20 treatments. Results showed that in all 20 treatments the quality of produced compost was in the standard range. Due to the high levels of nitrogen in raw material of some treatments, (e.g. treatments that percentage of cow dung and kitchen waste are zero such as M, N, O, Q, R and U) the concentration of N in mature compost was higher than other treatments. The type of raw material in the medium has particular importance on the quality of compost. So that any change in the composition due to changes in the presence or absence of macro and micronutrients can influence the compost production process and reproduction of worm. Therefore, optimization of medium components, as shown in this study is of specific importance that has effect on the vermicomposting at low temperature.

The problem of reducing CO2 emissions from transport, a major contributor to the greenhouse effect, has become a growing concern for the scientific community and various international committees monitoring climate change. Energy savings in the transport sector are a key factor towards rational management of oil reserves, while new trends in the automotive market have already been established, supported by research on efficient and environmentally-friendly technologies and alternative fuels to face fossil fuel dependency. The road transport sector is an important part for most developed economies but also a major source of pollutant emissions. In this framework, this paper focuses on transport emissions along the main road axis in Greece, connecting the country’s two largest urban areas, during the years 2008-2014, a period of prolonged recession. Based on traffic data collected at the toll stations along the highway, greenhouse gas and pollutant emissions were calculated using the COPERT4 emission estimation tool. According to the results, a sharp fall in emissions is observed largely due to traffic volume reductions, but also due to a prevailing trend for larger displacement vehicles and technologically improved vehicles with better environmental standards.