Seasonal analysis of commonly prescribed antibiotics in Istanbul city.

Antibiotics are among the most common medicine groups since they are used to treat infectious diseases, as nutritional supplements in livestock breeding, and for preservation in the food industry. Turkey is among the highest antibiotic consumers in the world. In the present study, the most popular 14 antibiotics available in Turkey were monitored in one hospital sewage and two urban wastewater treatment plant influents and effluents seasonally in Istanbul province, the largest metropolitan center in Turkey. The present research aimed to develop a robust analytical method to determine 14 antibiotics, including six chemical groups, in environmental matrices which are considered significant antibiotic pollution sources, namely hospital sewage and urban wastewater. Solid-phase extraction (SPE) and UPLC-MS/MS analysis parameters included optimized column temperature, eluent, mobile phase, and flow rate. Three SPE cartridges were employed in recovery studies. The antibiotic recovery rates varied between 40 and 100%, and all analytes were identified within 3 min with UPLC-MS/MS under optimal conditions. It was determined that method detection limits (MDLs) varied between 0.07 and 2.72 µg/L for the antibiotics. In all seasons, the highest beta-lactam group antibiotic concentrations were identified in hospital sewage. The season with the greatest variety of antibiotics in urban wastewater was spring. Clarithromycin and ciprofloxacin were the antibiotics determined at the highest concentration in the influent and effluent of the wastewater treatment plant in all seasons. This study showed that the most widely used beta-lactam group antibiotics were found in high amounts in hospital sewage wastewater but in low concentrations in the treatment plants, and hence, it is seen that the degradability of beta-lactam group antibiotics was high. The presence of clarithromycin, ciprofloxacin, lincomycin, levofloxacin, and trimethoprim antibiotics in hospital sewage in higher amounts and also in inlet and outlet of wastewater treatment plants proves that those are resistant antibiotics.

Investigating the Combined Use of Enrichment Factor and Weather Research and Forecasting (WRF) Modelling for Precipitation Sample Source Identification: A Case Study in North Carolina, USA.

Pollutants emitted into the air not only have local effect but can also affect areas further from the source. The goal of this study was to assess a method for identifying the sources of element pollution in rainwater using enrichment factors supported by Weather Research and Forecasting (WRF) model. In this study, we collected nineteen rainwater samples at the two locations of Durham and Chimney Ridge in North Carolina, USA in July of 2014. The samples were analyzed for pH, conductivity and levels of major ions and a range of trace elements. These data showed that the pH of precipitation ranged between 3.91 and 6.65, with an average value of 4.98. The average electrical conductivity was 15.58 and 17.7 µS/cm for rainwater collected at Durham and Chimney Ridge, respectively. The lowest concentration of the elements analyzed was for thorium (Th) with an average concentration of 0.002 ppb, whereas the highest elemental concentration was for calcium (Ca) with an average concentration of 980.3 ppb. Enrichment factors for trace elements were assessed within three different groups as: (1) rarely enriched, (2) significantly enriched, and (3) highly enriched. Copper (Cu), zinc (Zn), arsenic (As), molybdenum (Mo), silver (Ag), cadmium (Cd), and lead (Pb) were highly enriched trace elements. The wind fields acquired by the WRF model indicated the probable contamination sources. Source identification indicated that the highest contribution of elements to precipitation was from industry. The results showed that the combined use of enrichment factors and the WRF model can be used to identify the sources of pollutants in precipitation samples.

Comparison the biodegradation of herbicide pyroxasulfone by some soil bacteria.

The biodegradation of pyroxasulfone (C12H14F5N3O4S), which is the selective herbicide in wheat farming in Turkey is compared with some soil bacteria. These microorganisms were isolated in collected soil samples in Thrace region of Turkey from an agricultural area previously unexposed to pyroxasulfone. The microbial biodegradation of pyroxasulfone was investigated using liquid experiments with identified cultures to determine which of the microorganisms shows best removal performance under agitated culture conditions. The experiments continued about two weeks.  Five different apparatuses, were set up and pyroxasulfone in 750 ppm concentration (advised concentration of wheat farmers) was added to each Erlenmayer flasks. Approximately 107CFU/ml of each bacteria added to these flasks. These flasks were shaken at 130rpm at 27 0C in sterile conditions for 8 days. Every day, each sample was collected by filtering from flasks and Chemical Oxygen Demand (COD), biochemical oxygen demand (BOD5), total organic carbon (TOC) was determined.  As a result of the study, best removal performance observed in Bacillus thuringiensis and Fusarium fujikuroi as 91 and 93% at 7 days in COD, 88 and 83% in BOD5, 90 and 86% in TOC parameters. The lowest performance was seen on Clostridium tetani species for COD, BOD5 and TOC as 55%, 61% and 60% respectively on 7 days. The performance for Bacillus simplex and Bacillus megaterium species occurred between 70% and 80% for these three parameters.

Sea water quality assessment of Prince Islands' beaches in Istanbul.

In this study, seawater samples were subjected to microbiological and physicochemical analysis (water temperature, pH, Secchi disc depth and ammonia) in the Prince Islands which are located in Marmara Sea, being one of the most popular swimming areas in Istanbul. The monitoring program of the study has been carried out in the summer for 6 weeks at eight stations around the Prince Islands. Measured total coliform values were between 5 ± 2 and 26 ± 55 and faecal coliform values were between 4 ± 2 and 24 ± 50 in the monitoring stations. A statistical study has been conducted to find the relationship between total and faecal coliform concentrations, and t tests were applied. There was no significant difference in each location of the Islands, except one location. The results were evaluated by comparing with national and EU bathing water standards. Results of the study show that deep sea discharges and sea currents contribute dilution of coliform concentration in a positive way, and locations near coastal zones of the islands have acceptable values which are required by the regulations.

Addressing the operational problems in a composting and recycling plant.

The Istanbul composting and recycling plant, constructed in 2001, is one of the few composting plants in Turkey. During test operations of the plant, it was reported that the weight of the oversize materials (OM) above a 80-mm sieve was about 40% of the total incoming waste. They mainly consist of plastic bags that were full of garbage, which resulted in operational problems in the plant. In this paper, the composition of OM was determined and evaluated, particularly to find the economic losses in the plant. It was determined that approximately 58% of the OM transferred to the landfill area due to operational failures and interruptions could be used at the plant with improved operational conditions. Otherwise, the plant would realize an annual economic loss of about 640,800 US$. Compost quality in the plant has been satisfactory, but source separated collection, at least the separation of the wet from the dry fraction, is needed to increase the amount of compost and recovered materials.

Municipal solid-waste management in Istanbul.

Istanbul, with a population of around 13 million people, is located between Europe and Asia and is the biggest city in Turkey. Metropolitan Istanbul produces about 14,000 tons of solid waste per day. The aim of this study was to assess the situation of municipal solid-waste (MSW) management in Istanbul. This was achieved by reviewing the quantity and composition of waste produced in Istanbul. Current requirements and challenges in relation to the optimization of Istanbul's MSW collection and management system are also discussed, and several suggestions for solving the problems identified are presented. The recovery of solid waste from the landfills, as well as the amounts of landfill-generated biogas and electricity, were evaluated. In recent years, MSW management in Istanbul has improved because of strong governance and institutional involvement. However, efforts directed toward applied research are still required to enable better waste management. These efforts will greatly support decision making on the part of municipal authorities. There remains a great need to reduce the volume of MSW in Istanbul.

Restoration of the Golden Horn Estuary (Halic).

Restoration of the iconic Golden Horn Estuary in Istanbul, Turkey was a substantial political, logistical, ecological, and social challenge. Forty years of uncontrolled industrial and urban growth resulted in thick layers of anoxic sediment, toxic bacteria, strong hydrogen sulfide odor, and ecologically unlivable conditions. The major components of restoration, spanning two decades, have included (1) demolition and relocation of industries and homes along the shore, (2) creation of wastewater infrastructure, (3) removal of anoxic sludge from the estuary, (4) removal of a floating bridge that impeded circulation, and (5) creation of cultural and social facilities. Although Turkey is not known as an environmental leader in pollution control, the sum of these efforts was largely successful in revitalizing the area through dramatic water quality improvement. Consequently, the estuary is once again inhabitable for aquatic life as well as amenable to local resource users and foreign visitors, and Istanbul has regained a lost sense of cultural identity. This paper focuses on literature review and personal interviews to discuss the causes of degradation, solutions employed to rehabilitate the estuary, and subsequent physicochemical, ecological, and social changes.