A statistical evaluation of the potential genotoxic activity in the surface waters of the Golden Horn Estuary.

The potential genotoxic activity in the surface waters of the Golden Horn Estuary was statistically evaluated utilizing a combination of appropriate parametric and non-parametric tests. The genotoxic activities that were associated with the water samples were determined by the SOS chromotest microplate assay. This assay utilizes ß-galactosidase activity, alkaline phosphatase activity, and four different solvent controls, to generate reliable results when corrected induction factors (CIF) are used as quantitative measurements of genotoxic activity. The CIF values were obtained from a total of 384 different genotoxic experiments that were grouped into subsets according to the respective seasons and the selected sampling locations. A total of 160 subsets were statistically compared to assess any possible differences between the pairs of groups, with 95% confidence limits. The findings of this study clearly indicate that some seasonal variations exist in the CIF values at several sampling sites. However, no potentially hazardous impact to the aquatic environment was found in the estuarine system.

Decolorization and COD reduction of UASB pretreated poultry manure wastewater by electrocoagulation process: a post-treatment study.

The performance of electrocoagulation (EC) technique for decolorization and chemical oxygen demand (COD) reduction of anaerobically pretreated poultry manure wastewater was investigated in a laboratory batch study. Two identical 15.7-L up-flow anaerobic sludge blanket (UASB) reactors were first run under various organic and hydraulic loading conditions for 216 days. Effects of operating parameters such as type of sacrificial electrode material, time of electrolysis, current density, initial pH, and electrolyte concentration were further studied to optimize conditions for the post-treatment of UASB pretreated poultry manure wastewater. Preliminary tests conducted with two types of sacrificial electrodes (Al and Fe) resulted that Al electrodes were found to be more effective for both COD and color removals than Fe electrodes. The subsequent EC tests performed with Al electrodes showed that optimal operating conditions were determined to be an initial pH of 5.0, a current density of 15mA/cm(2), and an electrolysis time of 20min. The results indicated that under the optimal conditions, about 90% of COD and 92% of residual color could be effectively removed from the UASB effluent with the further contribution of the EC technology used as a post-treatment unit. In this study, the possible acute toxicity of the EC effluent was also evaluated by a static bioassay test procedure using guppy fish (Lebistes reticulatus). Findings of this study clearly indicated that incorporation of a toxicological test into conventional physicochemical analyses provided a better evaluation of final discharge characteristics.

Co-composting kinetics of rose processing waste with OFMSW.

The objective of this study was to evaluate the kinetics of co-composting of rose processing waste (RPW) and organic fraction of municipal solid waste (OFMSW). Experimental data was obtained from 65-L batch reactors. Mixtures settled up with different ratios of RPW, OFMSW, inoculation, and bulking agent. The data was consisting of CO(2) evolution and inner temperature changing with time in the reactors. Decomposition process was evaluated based on rapidly and slowly biodegradable fractions of organic matter. The experimental data has been analyzed by kinetic models including the first-zero-order, first-first-order, Chen and Hashimoto's and Levi-Minzi's kinetic models using non-linear regression techniques. Kinetic parameters and rate constants were evaluated based on the average relative errors and coefficient of determination. The results of study showed that the best fitting kinetic model is the first-first-order.

Treatment of leachate by electrocoagulation using aluminum and iron electrodes.

In this paper, treatment of leachate by electrocoagulation (EC) has been investigated in a batch process. The sample of leachate was supplied from Odayeri Landfill Site in Istanbul. Firstly, EC was compared with classical chemical coagulation (CC) process via COD removal. The first comparison results with 348 A/m2 current density showed that EC process has higher treatment performance than CC process. Secondly, effects of process variables such as electrode material, current density (from 348 to 631 A/m2), pH, treatment cost, and operating time for EC process are investigated on COD and NH4-N removal efficiencies. The appropriate electrode type search for EC provided that aluminum supplies more COD removal (56%) than iron electrode (35%) at the end of the 30 min operating time. Finally, EC experiments were also continued to determine the efficiency of ammonia removal, and the effects of current density, mixing, and aeration. All the findings of the study revealed that treatment of leachate by EC can be used as a step of a joint treatment.

Reduction of COD in wastewater from an organized tannery industrial region by Electro-Fenton process.

Advanced oxidation processes (AOPs) have led the way in the treatment of aqueous waste and are rapidly becoming the chosen technology for many applications. In this paper, COD reduction potential of leather tanning industry wastewaters by Electro-Fenton (EF) oxidation, as one of the AOPs, was experimentally evaluated. The wastewater sample was taken from an outlet of an equalization basin in a common treatment plant of an organized tannery industrial region in Istanbul, Turkey. Treatment of the wastewater was carried out by an electrochemical batch reactor equipped with two iron electrodes, which were connected parallel to each other. The oxidation process was studied for optimization of H(2)O(2) and the electricity consumptions were observed at different contact times under different pH conditions (3.0, 5.0 and 7.2). In each case, electricity consumption for decreased COD mass was estimated. In this process, COD was reduced by 60-70% within 10 min. By taking into consideration the local sewerage discharge limit, applicability of EF process for the tannery wastewaters was evaluated.

Recent years status of sediment bed of Golden Horn (Istanbul) after year 1999.

Golden Horn is an estuary in Istanbul. It has connection with Marmara Sea directly and with Black Sea via Bosphorus, and was polluted by different kinds of industrial plants up to 1999. In addition to this, municipal wastewater of around one million people has been discharged to here. Greater part of the estuary was almost blocked off by sediment islands. Extensive effort was spent to dredge sediment in 1999. This created quite a convenient condition for aquatic medium in the estuary. In this research, the variations of chemical compositions of sediment bed were investigated to get clue about ecological conditions of the estuary. For that purpose, sediment samples were taken from 6 stations along the estuary in 2001, 2003 and 2004. The sediment samples were analyzed for inorganic and organic constituents. Meanwhile, water samples (from the surface and just above benthic mass) were also taken from the same 6 places and they were analyzed to verify the data from sediment samples. By this way, correlations between sediment mass and water body were determined.

Treatability of water-based paint wastewater with Fenton process in different reactor types.

Water-based paint wastewater which is formed during the coating step of metal surfaces performed with various spray processes include binders, pigments and additives. Binders and other additives may also affect the toxicity of the paint depending on the specific characteristics of the paint. This study deals with Water-based paint wastewater, which is hard to treat. Fenton oxidation process was principally used to treat the wastewater. Treatability runs were carried out by using rust (oxidized iron) particles obtained as a waste of the metal rolling process, as the Fenton's catalyst. In order to change the variables such as dimensions of the column, packing material size, reactive dosage, pH value and reaction time, the experiments on the basis of packed columns and mixed reactors were carried out to increase the COD removal. COD eliminations with pH adjustment were about 20%. With the contribution of Fenton process in both column and mixed-reactor studies, the COD removal was improved by about 80%.

Primary productivity in the Golden Horn.

The shores of the Golden Horn--once most important seaport of the region--represented throughout history a romantic and recreational venue. This tributary to the Bosphorus, however, became seriously polluted with the extensive industrialization and rapid population growth in Istanbul over the past century. Two main tributaries, the Alibeykoy and the Kagithane, dumped both liquid and solid waste from residential areas and industry (small and large-scale) into the Golden Horn. As a result of this pollution, the landward three to four kilometers of the estuary became swamped with sediment. The dominance of anaerobic activity resulted in a highly unpleasant smell, and the shallow depth as one progressed up the bay restricted navigation. In early 1997 The Istanbul Metropolitan Municipality began a dredging operation and gradually diverted all domestic and industrial wastewater discharge from the Golden Horn. Since then there have been remarkable improvements in water quality. This paper presents the state of eutrophication through the water body of the Golden Horn; parameters such as DO, TKN, NH(3)-N, NO(3)-N, the total phosphorus (TP) and dissolved phosphorus (PO(4)-P), phytoplankton and chlorophyll-a have been were analyzed in samples of water taken from various points in the Golden Horn. The presence of DO and the phytoplankton, both indicators of primary productivity in an aquatic body, has been evaluated in relation to former conditions.

Anaerobic digestion and methane generation potential of rose residue in batch reactors.

In the study, anaerobic digestion of residues from rose oil industry was investigated by using a laboratory scale completely mixed batch reactor in volume of 10 L and 4 small reactors in volume of 400 mL. Ten liters reactor isolated with a water jacket and 0.4 L reactors settled into a water bath were operated at 35 +/- 1 degrees C. The study supplies biochemical methane potential of hydrolyzed and original residues. Experimental results showed that hydrolyzed rose residue produced a bit more methane than original residue. Methane production results were analyzed with first-order and Chen&Hashimoto's models, and Chen&-Hashimoto's model was found to be more suitable than first-order kinetic model.

Comparison of halothane/thiopental and propofol anesthesia for strabismus surgery.

Day case surgery has become a widely accepted practice for many ophthalmological procedures including strabismus surgery. Prompt recovery from anesthesia and minimal postoperative morbidity are especially requested to the anesthesiologists to deal with the high day case surgery burden. The purpose of this study was to compare two anesthesia techniques, halothane/thiopental anesthesia and propofol anesthesia, for patients undergoing monocular strabismus surgery. We studied the level of postoperative consciousness, nausea and vomiting, ocular pain, starting oral intake and activity in 43 patients, ranging from 7 to 41 years of age. A scoring system was used to assess these parameters in the first postoperative 48 h. Although there was not a significant difference in the level of ocular pain, the propofol group had less morbidity in terms of having a better level of consciousness and appetite, less nausea and vomiting and enhanced activity than the halothane/thiopental group. We conclude that propofol anesthesia has significant advantages over halothane/thiopental anesthesia on an outpatient basis for strabismus surgery.

Somatostatin: possible cause of bacterial translocation in obstructive jaundiced rats.

The purpose of this study was to examine the effect of endogenous somatostatin hormone on bacterial translocation in obstructive jaundiced rats. Five groups of rats were studied: group I (n = 10), non-operated group (control); group II (n = 10), sham-operated group which underwent laparotomy and dissection of portal elements, while the common bile duct was not ligated and somatostatin was not injected; group III (n = 10), same as group II, plus injection of somatostatin; group IV (n = 10), common bile duct was ligated with laparotomy but somatostatin was not injected; group V (n = 10), same as group IV, plus somatostatin injection. The blood was analyzed for somatostatin, alkaline phosphatase, and bilirubin levels on the third and tenth days in all animals. At study termination (tenth day), peritoneal swab and blood cultures were taken, and liver, spleen, lung, and mesenteric lymph nodes were harvested for microbiological studies. Bacterial translocation levels were higher in groups III, IV, and V when compared with levels in groups I and II. Similar translocation levels were obtained when blood somatostatin levels were comparable. However, the highest translocation rate was found in groups IV and V in which the blood somatostatin level was also higher when compared with that in other groups. This finding shows that blood somatostatin level is increased in obstructive jaundice. This may explain the bacterial translocation and related sepsis found in obstructive jaundice.

Postoperative retention of urine in general surgical patients.

OBJECTIVE: To find out the incidence of retention of urine after various general surgical operations, and to assess the effects of applying a bag filled with warm water (40-45 degrees C), and encouraging early mobilisation onreducing the necessity for catheterisation. DESIGN: Open study. SETTING: Cumhuriyet University Hospital, Sivas, Turkey. SUBJECTS: 577 consecutive patients who had no history of urinary problems and had not already been catheterised, and who underwent general surgical operations between April 1989 and December 1991. MAIN OUTCOME MEASURE: Ability to pass urine spontaneously. RESULTS: 64 of 272 men (24%) and 47 of 305 women (15%) developed retention of urine (p = 0.02), and 15 and 11, respectively, required catheterisation. Patients were most likely to develop retention after repair of incisional hernia (13/32, 38%), midline laparotomy (19/82, 23%), and subcostal incisions (30/142, 21%), but there were no significant differences among these. Significantly more patients whose operations had lasted 60 minutes or more, and who had opiate analgesia, required catheterisation (5/232 compared with 21/345, p = 0.04, and 11/120 compared with 15 out of 457, p = 0.01, respectively). 85 of the 111 patients who went into retention (77%) were able to pass urine spontaneously after application of a bag containing warm water to the suprapubic region, and walking about. The mean period of catheterisation was 12 hours (range 4-76), and all patients but one passed urine spontaneously when the catheter was removed. Only two of the 26 patients who were catheterised developed microbiologically confirmed urinary tract infections. CONCLUSION: Retention of urine is a common complication after general surgical operations, but the necessity for catheterisation can be kept to a minimum by simple and inexpensive measures.