Determination of environmental factors influencing bacterial regrowth in drinking water distribution system

İçme suyu arııma tesisi çıkışında bakteriyel standartları sağlayan içme suyu, tüketiciye ulaşana kadar dağıtım sistemi içerisinde bir takım değişikliklere uğramakta ve heterotrofik bakteri sayısında artış meydana gelebilmektedir. Bursa İli içme suyu dağıtım sisteminde meydana gelen bakteriyel değişimlerin ve bunları etkileyen mikro-çevresel faktörlerin incelendiği bu çalışmada arıtma tesisi çıkışı itibari ile yaklaşık 10200 m’lik bir hat üzerinde çalışılmıştır. Bu hat üzerinde seçilen 5 noktadan alınan örneklerde pH, bulanıklık, bakiye klor, nitrat, orto-fosfat, amonyum azotu, TOK (Toplam Organik Karbon), HBS (Heterotrofik Bakteri Sayısı), toplam koliform ve AOK (Asimile Edilebilir Organik Karbon) ölçümleri yapılmıştır. Elde edilen sonuçlar Bursa İli içme suyu dağıtım sisteminde arıtma tesisinden başlayarak şehrin doğusuna doğru uzanan hat üzerinde uzaklığa bağlı olarak bakteri sayısının arttığını göstermiştir. TOK, AOK ve amonyum azotu azalırken HBS değeri artmıştır. Bu parametreler arasındaki korelasyon katsayıları sırası ile -0.57, -0.74 ve -0.80 olarak belirlenmiştir. Bu değerler seçilen iletim hattı boyunca mikro-çevresel faktörlerin bakteriyel çoğalma üzerindeki etkisini ortaya koymaktadır. TOK, AOK ve amonyum-azotu ile uzaklık arasındaki korelasyon katsayıları ise -0.64, -0.89, -0,87 dir. Bazı noktalarda bakteri sayısının içme suyu standardı limit değerlerinin üzerinde olması, dağıtım sistemindeki bakiye klor konsantrasyonunun (<0.2 mg.l-1) seçilen hat boyunca meydana gelen bakteriyel çoğalmanın kontrol edilmesinde yetersiz kaldığını ve suyun bakteriyel çoğalma potansiyeline sahip olduğunu işaret etmektedir. Anahtar kelimeler: İçme suyu, HBS, Koliform, Bakteriyel yeniden çoğalma, TOK, AOK.In the present study, variations in microbial quality of drinking water and influential micro-environmental factors were examined in the distribution system of Bursa City. A 10200 m length of distribution line from the treatment plant was designated as the study area. pH, turbidity, residual chlorine, nitrate, ortho-phosphate, ammonium nitrogen, TOC (Total Organic Carbon), HPC (Heterotrophic Plate Count), total coliform and AOC (Assimilable Organic Carbon) measurements were carried out in water samples which were collected from 5 different points of the distribution system. The results of this study, indicated that the number of bacteria increased with distance between treatment plant and east side of the city. HPCs were determined to be 29, 62, 101, 133 and 176 CFU.ml-1 for the sampling points of 1., 2., 3., 4. and 5., respectively. TOC concentrations for the same points were 3.45, 2.64, 2.13, 1.61 and 1.19 mg.l-1. AOC concentrations measured in samples of point 1, 3 and 5 were 126.3, 99.1 and 92.1 mgC.l-1. It is known that AOC which is decomposed easily and utilized directly in cell synthesis forms 0.1-9% of TOC. In the present study, mean AOC concentration of water was measured to be 105.8 mgC.l-1 and formed 4-8% of TOC (2.2 mg.l-1). Standard value for HPC is 100 CFU.ml-1 according to WHO (World Health Organization) and AOC is required to be below 10 mgC.l-1 in order to accomplish this standard. However, bacterial regrowth appears to be inevitable in our distribution system since mean AOC concentration (105.8 mgC.l-1) was much above of this standard. Ammonium nitrogen concentrations were measured to be 0.26, 0.22, 0.17, 0.11 and 0.11 mg.l-1 for the sampling points of 1., 2., 3., 4. and 5., respectively. Decreasing TOC, AOC and ammonium nitrogen concentrations were followed by increasing HPC. Correlation coefficients between HPC and TOC, AOC, and ammonium nitrogen were found to be -0.57,    -0.74 and -0.80, respectively. These values signify the effect of micro-environmental factors on microbial growth. Concentrations of TOC, AOC and ammonium nitrogen decreased significantly with increasing distance from treatment plant. Correlation coefficients between distance and TOC, AOC and ammonium nitrogen were found to be -0.64, -0.89 and -0.87. Nitrate concentrations for the sampling points were measured to be 3.05, 3.13, 3.15, 3.50 and 4.15 mg.l-1 and indicated an increasing trend line with distance. It is thought that potential nitrification process cause this increase in nitrate concentrations.  A positive correlation (0.57) was determined between nitrate concentration and HPC whereas no correlation (0.37) existed between nitrate concentration and distance. Orhto-phosphate concentrations were measured to be 0.110, 0.087, 0.106, 0.082 and 0.078 mg.l-1 for the same points. Although HPC increased with increasing ortho-phosphate at the end section of distribution system, no powerful correlation (-0.13) was determined between these parameters. Reduction of ortho-phosphate concentration in the distribution system indicated that ortho-phosphate was likely to be utilized by bacteria as a nutrient along with ammonium nitrogen and AOC. It is known that marginal variations in inorganic phosphate concentrations may stimulate bacterial growth in distribution systems. Mean pH values were measured to vary between 7.24 and 7.47 and this variation was found to be insignificant. However, this level of pH was thought to be appropriate for bacterial growth. Turbidity of water did not vary significantly in the distribution system. Mean turbidity levels were determined to be 2.49, 2.13, 2.36, 1.93 and 2.17 NTU for the sampling points of 1., 2., 3., 4. and 5., respectively. Mean turbidity level determined in the present study appears to comply with the drinking water standards. In general, turbidity is expected to increase with the increasing number of bacteria in water. However, turbidity doesn?t increase unless bacterial growth occurs at significant levels. Therefore, in the present study, turbidity of water remained at reasonable levels as a result of minor increases of HPC in water. Residual chlorine was found to be below 0.2 mgl-1 at all sampling points, indicating that residual chlorine in the distribution system was not maintained at a level to control bacterial growth. Accordingly, HPC in water increased with distance, which provided convincing evidence for inadequate regrowth control in the distribution system. Microbiological parameters measured in this study showed that microbial quality of water was at a level which would not show any adverse effects on human health. However, bacteriological quality and AOC level of the water must be monitored continuously since the bacterial regrowth potential exists. Keywords: Drinking water, HPC, Coliform, Bacterial regrowth

Sağlık Turizmi ve Uluslararası Hastalar İçin Türkiye Pazarı

Günden güne hem kamu, hem de özel hastanelerin sayısı artmaktadır. Ulusal hastalara ait sabit bir pazar olması, sağlık sektöründe büyük bir rekabeti de beraberinde getirmektedir. Türkiye coğrafik konumu, iklimi, termal kaynakları, doğal güzellikleri, kaliteli tıp personeli ve yüksek teknoloji kullanan aletlere sahip hastaneleri ile sağlık turizmi için büyük bir potansiyele sahiptir. Sağlık turizminin 2011 yılı verilerine göre dünyadaki pazar payı yaklaşık olarak 400 milyar dolardır. Bu çalışma ile Türkiye’nin bu pazardaki mevcut durumunu ortaya koyarken; gelecekte bu pazardaki payını daha da artırabilmek için gereken öneri ve düzenlemelerin geliştirilmesi amaçlanmıştır. Hastalara ait veriler Sağlık Bakanlığı ile Kültür ve Turizm Bakanlığı’nın resmi sitelerinden alınmıştır. 2010 yılında, sağlık turizmi için 109-678 hasta Türkiye’ye gelmiştir (Özel hastane: 77.003; kamu hastanesi: 32.675 kişi). Hastaların geldikleri ülke ve aldıkları sağlık hizmetine göre farklı dağılımlar sergilediği görülmektedir. Kamu hastanelerinin yanı sıra özel hastanelerin sayısı da günden güne artmakta ve bu sektörde önemli bir yer almaktadırlar. Sağlık sektöründe pazarı arttırmak için Sağlık Bakanlığı ile Kültür ve Turizm Bakanlığı sağlık turizmine gereken önemi vermelidir. Bu yolla oluşan döviz girdisi sağlık sektöründe pazar payını arttırırken; ortaya çıkan yeni iş olanakları işsizliği azaltacaktır. Sağlık sektörünün ayakta kalması için sağlık turizmi gün geçtikçe daha önemli hale gelmektedir

İdarubisin yüklü manyetik nanoparçacıkların sentezlenmesi ve MCF-7 meme kanseri hücre hattına uygulanması

TÜBİTAK TBAG Proje01.07.2012Conventional cancer chemotherapies cannot differentiate between healthy and cancer cells, and lead to severe side effects and systemic toxicity. In the last decades, different kinds of controlled drug delivery systems have been developed to overcome these shortcomings of chemotherapeutics. These studies aim targeted drug delivery to tumor side at the right time. Magnetic nanoparticles (MNP) are potentially important in cancer treatment since they can be targeted to tumor site by an externally applied magnetic field. In this study, firstly MNP were synthesized. Obtained particles were covered with biocompatible polyethylene glycol (PEG); and then conjugated with folic acid. Anticancer drug idarubicin was loaded to nanoparticles and drug release studies were performed. Shape and size, crystal and chemical structures, and magnetic properties of synthesized nanoparticles were characterized. Agglomeration tendency of naked nanoparticles was prevented to a reasonable degree by oleic acid addition during the synthesis. All synthesized MNP have been found to exhibit superparamagnetic behavior at 23˚C and 37˚C. Cytotoxic effects of MNP were investigated on MCF-7 breast cancer cell line. Before drug loading, MNP did not have any toxicity in the concentration ranges of 0 – 500 µg/ml while drug loaded nanoparticles led to significant toxicity in a concentration dependent manner. Idarubicin loaded to MNP exhibited more toxicity compared to free idarubicin on MCF-7 cells. Endocytosis of MNP was illustrated by light and confocal microscopy images. The synthesized nanoparticles have been found to be suitable in terms of size, shape, magnetic and cytotoxic properties for drug targeting or other biomedical applications. The obtained results are expected to contribute to in vitro and in vivo cancer chemotherapy studies

INVESTIGATION OF DESORPTION KINETICS AND EQUILIBRIUM OF AN ANIONIC DYE FROM MAGNETIC POLYMER ADSORBENTS

Dyes, which are used in different industries such as paper, plastics, leather, pharmaceutical, food, cosmetics, textiles, etc., constitute a major class of environmental pollutants. In recent studies, magnetic adsorbents combining magnetic separation technology with the adsorption process has been used to remove dyes from industrial wastewaters. The main advantages of the adsorbents are possible to be easily and simply separated from process media in a short time using the external magnetic field and will be reused. In present work, desorption behavior of the dye adsorbed particles was investigated. For this purpose, magnetic polymeric particles were used as adsorbents and Bromothymol Blue (BB) selected as an anionic dye. In order to determine the desorption pattern of the anionic dye from the magnetic polymeric particles, the particles were suspended in phosphate-buffered saline solution and maintained at 150 rpm. At predetermined time intervals, the samples were removed and the amount of desorbed BB was analyzed with a UV-vis spectrophotometer. The desorption kinetics and equilibrium of BB from the particles with time in pH 7.4 and 5 phosphate buffer solutions have clearly shown that the desorption of BB is affected by the characteristics (nano/micro) of the particles and there are significant differences in the desorption profiles between pH values

Tailoring magnetic PLGA nanoparticles suitable for doxorubicin delivery

One of the main problems of current cancer chemotherapy is the lack of selectivity of anti-cancer drugs to tumor cells, which leads to systemic toxicity and adverse side effects. In order to overcome these limitations, researches on controlled drug delivery systems have gained much attention. Nanoscale-based drug delivery systems provide tumor targeting. Among many types of nanocarriers, superparamagnetic nanoparticles with their biocompatible polymer coatings can be targeted to an intented site by an external magnetic field. Thus, the drug can be carried to the targeted site safely. The aim of this study is to prepare poly(dl-lactic-co-glycolic acid) (PLGA)-coated magnetic nanoparticles and load anti-cancer drug, doxorubicin to them. For this purpose, magnetite (Fe3O4) iron oxide nanoparticles were synthesized as a magnetic core material (MNP) and then coated with oleic acid. Oleic acid-coated MNP (OA-MNP) was encapsulated into PLGA. Effects of different OA-MNP/PLGA ratios on magnetite entrapment efficiency were investigated. Doxorubicin-loaded magnetic polymeric nanoparticles (DOX-PLGA-MNP) were prepared. After the characterization of prepared nanoparticles, their cytotoxic effects on MCF-7 cell line were studied. PLGA-coated magnetic nanoparticles (PLGA-MNP) had a proper size and superparamagnetic character. The highest magnetite entrapment efficiency of PLGA-MNP was estimated as 63 % at 1:8 ratio. Cytotoxicity studies of PLGA-MNP did not indicate any notable cell death between the concentration ranges of 2 and 125 mu g/ml. Drug loading efficiency was estimated as 32 %, and it was observed that DOX-PLGA-MNP showed significant cytotoxicity on MCF-7 cells compared to PLGA-MNP. The results showed that prepared nanoparticles have desired size and superparamagnetic characteristics without serious toxic effects on cells. These nanoparticles may be suitable for targeted drug delivery applications

The effect of ultrasonication on the size and morphology of iron oxide - chitosan nano and microparticles

The aim of this study is to synthesize magnetic Fe3O4-chitosan nano and microparticles (Fe3O4-CPs) by suspension cross-linking and ionic gelation methods and investigate the effect of ultrasonication on the size, morphology and magnetic properties. The synthesized particles were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS) and vibrating sample magnetometry (VSM). The results showed that the ultrasonication decreased the mean particle diameter and enhanced magnetic properties of Fe3O4-CPs due to the Fe3O4 content

Magnetic Fe3O4-chitosan micro- and nanoparticles for wastewater treatment

In this study, first, magnetic nanoparticles (MNP) were synthesized using a coprecipitation method and the synthesized particles were characterized using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), dynamic light scattering (DLS), and vibrating sample magnetometry (VSM). According to DLS and VSM analyses results, it was seen that the size of the MNP was smaller than 10 nm and they exhibited superparamagnetic properties, respectively. Then, magnetic Fe3O4-chitosan micro/nanoparticles were synthesized using a suspension cross-linking method in the presence of the MNP. Fe3O4-chitosan microparticles (Fe3O4-CMs) and Fe3O4-chitosan nanoparticles (Fe3O4-CNs), which have different structural, morphological, and magnetic properties, were obtained. All of the particles were characterized using transmission electron microscopy (TEM), FTIR, TGA, DLS, and VSM. In the second part of the study, the dye adsorption properties of the two different adsorbents from aqueous solution were investigated. For these purposes, Bromothymol Blue (BB) was used as a dye and the parameters affecting adsorption of BB (contact time, initial dye concentration, temperature and pH) were investigated. When the optimum adsorption conditions were provided for each adsorbent, the adsorption capacities of Fe3O4-CNs and Fe3O4-CMs were 82.2 and 193.3 mg/g, respectively