Eylem Kiliç

Chromium recovery from tannery sludge with saponin and oxidative remediation

Two new methods for treatment of tannery sludge were studied to achieve cost-effective and environmentally acceptable remediation solutions for high chromium containing tannery sludge. Quillaja bark saponin, a plant derived biosurfactant, was applied to dewatered tannery sludge for chromium recovery and a comparative assessment with H(2)O(2) oxidative treatment method is presented. Tannery sludge samples were treated on a laboratory scale with saponin in the pH range 2-3. The effects of various factors like time, concentration of saponin, pH, and temperature on the extraction of chromium were studied. The treatment with saponin extracted 24% of Cr from tannery sludge at a pH around2, performing multiple wash of 6h, at 33 °C. On the other hand, the H(2)O(2) treatment, which include Cr(III) oxidation to Cr(VI) and extraction with sulfuric acid solution at pH 2, enabled to extract 70% of chromium within less than 4h at room temperature (21 °C). The results indicate that the extraction efficiency of saponin was strongly dependent on the organic matter content of the sample, which affects chromium mobility by its high adsorption capacity. On the other hand hydrogen peroxide treatment is effective and the duration of the process is short and requires cheap chemicals and moderate conditions.

Environmental optimization of chromium recovery from tannery sludge using a life cycle assessment approach

Life cycle assessment (LCA) was used to evaluate the environmental impact of an oxidative chromium recovery method from tannery sludge, in comparison with the usual landfilling process. Three improvement options (water reduction, byproduct use and anaerobic sludge digestion) were considered. The results showed that the proposed chromium recovery process would be better environmentally than conventional landfilling in all the evaluated impact categories if the amount of chromium recovered was 43 kg per ton of sludge. This amount could be recovered if the chromium concentration was about 20 times higher than that considered in this study. Alternatively, a lower chromium concentration would produce a better result if the recovery method was optimized and implemented at industrial rather than laboratory scale, and if more accurate data were provided on environmental credits for avoiding the chromium production process. Thus, the recovery method is environmentally beneficial when tannery sludge contains a chromium concentration of about 100,000 ppm. According to the literature, such concentrations are not unusual. The results could serve as the basis for further environmental improvements in chromium recovery and tannery sludge management and should be used in decision-making processes, especially for end-of-pipe treatments.

Eco-Friendly Soaking Process Using Tannic Acid as an Alternative Bactericide

Abstract Eco-friendly leather processes based on the usage of natural products have become a potentially attractive issue for leather industry during the last few decades. Synthetic protective chemicals like bactericides used in most soaking process are known as hazardous substances and cause tannery effluents with high concentrations of Chemical Oxygen Demand (COD). In the present study, the effect of tannic acid on microorganisms, skin, wool and effluent were investigated in order to demonstrate the applicability of tannic acid in soaking process instead of commonly used bactericides. The bacterial load (cfu/ml), COD and Nitrogen Content (N) of the soaking effluents and Total Kjeldahl Nitrogen (TKN) content of skins and wools were investigated. Application of 0.5 and 1 wt% tannic acid concentrations was more effective than commercial bactericide, while comparable results were achieved by 0.1 and 0.3 wt% tannic acid. The application of tannic acid for soaking process resulted in lower COD and N values of effluents. The results show that tannic acid has the potential to be an alternative, eco-friendly bactericide for leather industry by reducing the pollution of leather soaking process.

Corporate carbon footprint for country Climate Change mitigation: A case study of a tannery in Turkey

Assessment of carbon emissions and environmental impact of production is indispensable to achieve a sustainable industrial production in Turkey, especially for those companies willing to compete in new international green markets. In this case study, corporate carbon footprint of a representative Turkish tanning company was analyzed. Inventory and impact data are presented to help in the environmental decision-making process. The results indicate that significant environmental impacts were caused during the landfilling of solid wastes as well as the production of the electricity and fuel required in the tannery. Turkish tannery inventory data presented here for the first time will be useful for leather tanning company managers to calculate sustainability key indicators. Improving alternatives at country level were identified (increasing the renewable sources on electricity production and promote energy recovery in landfills) which would be useful not only to decrease greenhouse gas (GHG) emissions of tanning sector but also of other industries requiring electricity and producing organic wastes. Considering the substantial contribution of industrial processes to the Turkish carbon emissions (15.7%) (TUIK, 2013), work done on those areas would provide a sound improvement in environmental profile of Turkey. The importance to promote a national strategy to reduce GHG emissions in Turkey was discussed here, as well as its relation to corporate carbon footprint assessments. One of the significant points revealed from the case study is the lack of published country specific emission factors for Turkey, which is a fundamental prerequisite to promote corporate carbon footprint assessment within the country.

Inventory analysis and carbon footprint of coastland-hotel services: A Spanish case study

Tourism is a key industry in the Spanish economy. Spain was in the World top three ranking by international tourist arrivals and by income in 2015. The development of the tourism industry is essential to maintain the established economic system. However, if the environmental requirements were not taken into account, the country would face a negative effect on depletion of local environmental resources from which tourism depends. This case study evaluates, through a life cycle perspective, the average carbon footprint of an overnight stay in a Spanish coastland hotel by analyzing 14 two-to-five-stars hotels. Inventory and impact data are analyzed and presented both for resource use and greenhouse gases emissions, with the intention of helping in the environmental decision-making process. The main identified potential hotspots are electricity and fuels consumption (6 to 30kWh/overnight stay and 24 to 127MJ/overnight stay respectively), which are proportional to the number of stars and unoccupancy rate and they produce more than 75% of the impact. It is also revealed that voluntary implementation of environmental monitoring systems (like EMAS regulation) promotes collection of more detailed and accurate data, which helps in a more efficient use of resources. A literature review on LCA and tourism is also discussed. Spanish hotels inventory data presented here for the first time will be useful for tourism related managers (destination managers, policy makers and hotel managers among others) to calculate sustainability key indicators, which can lead to achieve real sustainable-tourism goals. Further data collection will be needed in future projects to gather representative data from more hotels, other accommodation facilities and also other products/services offered by tourist sector in Spain (like transport of tourists, food and beverage, culture-sports & recreation and others).