Life cycle assessment of a wind farm in Turkey.

The aim of this study is to investigate the environmental impacts of a full-scale wind farm using life cycle assessment methodology. The facility in question is an onshore wind farm located in Turkey with a total installed capacity of 47.5 MW consisting of 2.5 MW Nordex wind turbines. Hub height and rotor diameter of the wind turbines are 100 m. The system boundary is defined as material extraction, part production, construction, operation and maintenance and decommissioning phases of the wind farm. The functional unit is 1-kWh electricity produced. Environmental impacts are mainly generated by manufacturing and installation operations. Steel sheet usage in tower manufacturing is the main contributor to abiotic depletion of fossil resources, acidification, eutrophication, global warming and marine aquatic ecotoxicity potentials. Apart from ozone layer depletion, end-of-life phase decreases the environmental impacts due to metal recycling. Metal recycling ratio scenario results show that when the recycling ratio decreases from 90 to 20%; increases of 110%, 102%, 92% and 87% are observed in acidification, terrestrial ecotoxicity, marine aquatic ecotoxicity and global warming potentials, respectively. In the baseline, the main parts which are manufactured in Germany are transported by sea to Turkey. Transportation scenario involves shifting the manufacturing of main parts to Turkey then transporting these parts by trucks to the farm. This conversion causes increases of 31%, 35% and 27% in abiotic depletion of fossil resources, freshwater aquatic ecotoxicity and global warming potentials, respectively, while causing decreases of 11% and 4% in acidification and eutrophication potentials generated by transportation activities, respectively.

Life cycle assessment of a large water treatment plant in Turkey.

The objective of this study is to assess the environmental sustainability of a large water treatment plant through life cycle assessment (LCA) approach. This study is a pioneering one that explores the environmental impacts of a water treatment plant in Turkey by using the data collected from an actual plant. Decision makers of the treatment plant under investigation, operators of similar installations, and the scientific researchers that work on LCA of water treatment facilities are defined as the target audience. GaBi software is used for the LCA model, and CML 2001 method is adopted to calculate the results given per 1 m3 water ready to be distributed to the city. The plant serves about 2,600,000 people generating a maximum potable water flow rate of 400,000 m3/day. In the facility, 0.57 kWh of electricity is required to obtain 1 m3 of water. Of this total electricity consumption, 85% is allocated to inlet and outlet pumping stations. The results denote that the environmental impacts are dominated by electricity consumption that in turn depends on the energy source/s adopted. Sensitivity analysis on energy sources reveals the following outcomes: In case of using hard coal as energy source rather than grid mix, impacts are increased apart from freshwater aquatic ecotoxicity potential, ozone layer depletion potential, and abiotic depletion potential elements. Once solar panels are used instead of grid mix, values for all impact categories except abiotic depletion potential elements and human toxicity potential are lowered. The usage of wind turbines in place of grid mix results in 29 to 84% reductions in all investigated impact categories. The best option to decrease the environmental impacts is attained when energy is generated using wind turbines. As pumps having 90% efficiency replace the pumps with 60% efficiency, reductions ranging from 15 to 24% on all impact categories are obtained. The work performed for this study should be further pursued to obtain more representative inventory data for countries with scarce LCA studies.

Life cycle assessment of a printed circuit board manufacturing plant in Turkey.

The objective of this study is to investigate the environmental impacts of a printed circuit board (PCB) manufacturing plant through streamlined life cycle assessment approach. As a result, the most effective recommendations on minimizing the environmental impacts for the mentioned sector are revealed and first steps towards establishing a country specific database are taken. The whole PCB production consists of two consecutive stages: namely board fabrication followed by the manufacturing of PCB. Manufacturing of PCB contributes the highest shares to freshwater aquatic ecotoxicity potential (FAETP) and ozone layer depletion potential (ODP). Eighty-nine percent of FAETP is found to be generated from the manufacturing of PCB. Almost all of this contribution can be attributed to the disposal of copper containing wastewater treatment sludge from etching operations to incineration. On the other hand, PCB manufacturing has 73% share in total ODP. Within the manufacturing of PCB, as etching operations are found to be of importance for all the impact categories except eutrophication potential (EP), it is recommended to focus further studies on in-plant control of etching.

Pre-ozonation of commercial textile tannins: effects on biodegradability and toxicity.

The effect of ozonation on the biodegradability and acute toxicity of two frequently used textile dye assisting chemicals, namely natural tannin (NT) having an initial chemical oxygen demand (COD0) of 1195 mg L-1; initial total organic carbon (TOC0) of 342 mg L-1; initial 5th-day biochemical oxygen demand (BOD5,0) of 86 mg L-1; initial ultraviolet absorbance at 280 nm wavelength (UV280,0) of 32.2 cm-1; initial ultraviolet absorbance at 254 nm wavelength (UV254,0) of 19.35 cm-1 and synthetic tannin (ST); with a COD0 of 465 mg L-1; TOC0 of 155 mg L-1; BOD5,0 of 6 mg L-1; UV280,0 of 11.78 cm-1; UV254,0 of 13.74 cm-1 was investigated. Synthetic wastewater bearing these tannin formulations was individually prepared and subjected to ozonation at varying doses (500 and 1000 mg h-1), and pHs (3.5 and 7.0) to elucidate the effect of ozone dose and pH on oxidation efficiency. Changes in the environmental sum parameters chemical oxygen demand (COD), total organic carbon (TOC), 5th-day biochemical oxygen demand (BOD5), ultraviolet absorbance at 280 nm wavelength (UV280) and ultraviolet absorbance at 254 nm wavelength (UV254), the latter two representing the aromaticity and double bonds of the studied textile tannins, respectively, were monitored during the course of ozonation. In the second part of the study, the biodegradability and acute toxicity of the raw and pre-ozonated textile tannins were evaluated in terms of the BOD5 parameter and an activated sludge inhibition test, respectively. Results indicated no significant changes in acute toxicity for NT, whereas the inhibitory effect of ST could be completely eliminated after 40 min ozonation at a rate of 1000 mg h-1 (i.e., at a specific ozone dose of 1.4 mg (O)3 (mg COD0)-1 and a pH of 3.5. In conclusion, pre-ozonation appeared to be potential pretreatment option to achieve complete detoxification and a fair biodegradability improvement of the otherwise refractory synthetic tannin.

Effect of textile auxiliaries on the biodegradation of dyehouse effluent in activated sludge.

The textile industry is confronted with serious environmental problems associated with its immense wastewater discharge, substantial pollution load, extremely high salinity, and alkaline, heavily coloured effluent. Particular sources of recalcitrance and toxicity in dyehouse effluent are two frequently used textile auxiliaries; i.e. dye carriers and biocidal finishing agents. The present experimental work reports the observation of scientific and practical significance related with the effect of two commercially important textile dye carriers and two biocidal finishing agents on biological activated sludge treatment at a textile preparation, dyeing and finishing plant in Istanbul. Respirometric measurements of the dyehouse effluent spiked with the selected textile chemicals were carried out for the assessment of the "readily biodegradable COD fraction" of the wastewater. The respirometric data obtained to visualize the effect of the selected textile auxiliaries on biomass activity was evaluated by an adopted activated sludge model. Results have indicated that the tested biocides did not exert any significant inhibitory effect on the treatment performance of the activated sludge reactor at the concentrations usually encountered in the final, total dyehouse effluent. The situation with the dye carriers was inherently different; one dye carrier appeared to be highly toxic and caused serious inhibition of the microbial respirometric activity, whereas the other dye carrier, also known as the more ecological alternative, i.e. the "Eco-Carrier", appeared to be biodegradable. Finally, the respirometric profile obtained for the Eco-Carrier was described by a simplified respirometric model.

Ozonation of nonbiodegradable organics in tannery wastewater.

The study explores the impact of ozonation on the fate of different soluble COD fractions in the tannery wastewater at different phases during the course of biological treatment, in order to identify the phase where ozonation is likely to generate the maximum beneficial effect on biological treatability. Samples from the biological treatment influent and from the mixed liquor at periods significant for the fate of COD fractions have been ozonated. Ozone treatment at the phase where the readily biodegradable COD component was biologically depleted is determined as the most promising alternative among others, since the highest COD removal efficiencies are achieved even with low feeding time of 5 min at the selected ozone flow-rate of 42.8 mg min. The merit of ozonation at this stage in the formation of simpler more biodegradable compounds deserves further attention.

Feasibility analysis of in-plant control for water minimization and wastewater reuse in a wool finishing textile mill.

This study evaluates the feasibility of water minimization and wastewater reuse for a wool finishing textile mill. The evaluation process is based upon a detailed analysis on water use, process profile and wastewater characterization, indicating a potential for 34% reduction in water consumption and for 23% of wastewater recovery for reuse. Wastewater reuse requires treatment and results in a remaining wastewater stream with stronger character and consequently more costly to treat. The feasibility includes technical considerations for appropriate treatment alternatives and related cost factors for water consumption, treatment for reuse and for discharge either to sewer or to receiving media.

Wastewater reuse for the minimization of fresh water demand in coastal areas--selected cases from the textile finishing industry.

Availability of water to the industry often becomes prohibitive, both in terms of quality and cost, in coastal areas. This study takes the textile industry and evaluates the prerequisites of water recovery and reuse. In this context, a large spectrum are studied for their water, the general quality of wastewater generated, quality and treatability of reuse wastewater streams, and expected changes in the overall effluent quality after segregation of the recovery wastewater portion.