No abstract

Hair analysis is a promising tool for routine clinical screening and diagnosis of heavy metal exposure and essential trace element status in the human body. Systemic intoxications have been identified by anomalously high values of toxins in hair samples. The aim of the present study is to evaluate the relationship between smoking habit of the family members and the levels of toxic and nontoxic trace elements in hair samples of children. The randomized cross-sectional controlled study comprised of 95 children (41 girls and 54 boys) between the ages of 1 and 6 years. After written informed consent was obtained, a face-to-face interview was conducted with the families about educational background, total income of the family, and smoking habits of family members. The mineral elements considered in this study were Zn, Se, B, V, Co, Mo, Mn, iron (Fe), Be, aluminum (Al), As, cadmium (Cd), lead (Pb), Hg, chromium (Cr), Ag, Be, nickel (Ni), copper (Cu), Sn, and antimony (Sb). Hair mineral contents were measured by inductively coupled plasma-mass spectrometry. The results showed that the levels of Cd, Pb, Cr, Sb, Fe, and Al in hair samples of children whose parents smoked were significantly higher than those whose parents were nonsmokers. The number of smokers and the frequency of smoking at home were positively correlated with Pb, Cd, Cu, Ni, and Sb levels found. At the same time, it was found that there was no correlation between toxic element concentrations and family income or educational background excluding the levels of Cd. A correlation was observed between the smoking status of family members and levels of toxic trace elements in hair where this correlation was more significant with the levels of Pb and Cd. High socioeconomic status and the level of education of family members did not have any effect on toxic trace levels in hair samples of children.

The production of excess sludge is one of the most serious challenges in biological wastewater treatment. In the present work, disintegration is added as a new additional unit operation in a wastewater treatment plant, and the main objective is to reduce the amount of excess sludge. The use of high power ultrasound can effectively disintegrate the bacterial cells, and thereby, enhance the subsequent biodegradation during digestion. In the study, attempts are made to determine the disintegration capacity of waste activated sludge that has different total solids (TS) concentrations with low ultrasound frequency (20 kHz) and a fixed amplitude value (50%). The results show that in terms of soluble chemical oxygen demand (SCOD) release, sludge disintegration was primarily governed by ultrasonic density (W mL -1 ), whereas specific energy input appears to be more critical for protein release. A SCOD release of about 329 mg SCOD gTS -1 was obtained at a TS content of 2% and specific energy input of 5 kWs gTS -1 . The SCOD release decreased to 248.5 and 124.2 mgSCOD gTS -1 at TS contents of 4 and 6%, respectively. The highest protein release of 80.7 mg gTS -1 was obtained at a TS content of 2% and a specific energy input of 10 kWs g -1 . The sludge disintegration efficiency declined significantly at higher TS content.

Hospital laboratory wastewater has been considered to significantly change the degree of contamination of especially the hospital wastewater. The present study investigated the hospital clinical laboratory wastewater and the pollution loads were assessed for pathogens, heavy metals, and organic materials. Composite samples were collected from clinical laboratory wastewater of a 350-bed hospital for a six-month period. Analyses for pH, TSS (Total Suspended Solid), BOD (Biochemical Oxygen Demand), COD (Chemical Oxygen Demand), PO4-P, and Cl as well as heavy metals (Cd, Pb, Zn, Cu, Cr, Co, Ni, Al, and Mn) were made in order to physiochemical properties of the samples. Bacterial isolation (Pseudomonas aeruginosa, Escherichia coli, Acinetobaumanii, CNS-CoagulaseNegative Staphylococcus) and antigen-antibody analyses were conducted in order to find the microbiological pollution load of the wastewater. As a result of the study it was found that the hospital clinical laboratory wastewater was alkaline and COD/BOD ratio reached to a range of 10 -12 in the wastewater. It was concluded that although the heavy metal concentrations were within the sewage discharge limits the said levels could pose health risk. It was also found that the wastewater entailed health risk due to pathogens.

No abstract

Gökçekaya Dam is one of the dams located on the Sakarya River (Eskişehir) in Turkey and is approximately 38 years old. No study regarding to the water quality of the dam lake has been hitherto made. This study aimed at determining the seasonal variations with physical, chemical, and biological parameters of the water quality of the dam lake. Depth-wise water samples were taken from five selected stations, in seasonal periods during 2005-2008, and anlayzed. The quality of water was classified in accordance with the results and taking into consideration many parameters. At the same time, number and type diversities of dissolved heavy metals and algae population were analyzed. Using principal component analysis (PCA) and classification analysis (CA) methods, differences between these parameters and samples from stations have been determined . The analysis showed that Gökçe-kaya dam lake, formerly an oligotrophic lake, has become a mesotrophic lake. And according to the results thereof the Lake has mezotrophic characteristics due to the sudden changes (including household waste water inflow and opening the Sarıyar dam lake shutters) in certain periods and in some stations. Hierarchical clustering analysis, revealed no significant difference between the measured parameters. And according to the Water Pollution Control Regulations in Turkey (WPCR) Gökçekaya dam lake is in the first class quality in terms of anions, cations, heavy metals, temperature, and pH values. However, the is of first class quality presence of nitrite reduces the water quality in the lake and causes this lake to be classified in the fourth class quality.

Waste activated sludge (WAS) is more difficult to digest than primary sludge due to rate limiting cell hydrolysis. High-power ultrasound can effectively disintegrate the bacterial cells and thus enhance the subsequent digestion. This research examines the effectiveness of ultrasound pretreatment on WAS disintegration at different specific energy inputs, ultrasonic densities and total solids (TS) contents. The results show that the cut diameter (d50) for WAS with 2% TS content declined nearly 6.5-fold at an ultrasonic density of 0.67 W/ml. For higher TS contents of 4 and 6%, higher densities of 1.03 and 0.86 W/ml, respectively, were needed to achieve the same degree of particle size reduction. The efficacy of ultrasonic disintegration measured as soluble chemical oxygen demand (SCOD) release was primarily governed by ultrasonic density (W/ml); whereas ultrasonic density did not show a significant effect on protein release at all TS levels. SCOD release of about 320 mg SCOD/g TS was obtained at a TS content of 2% and specific energy input of 5 kWs/gTS. The SCOD release, however, decreased to 160 and 90 mgSCOD/gTS at 4 and 6% TS contents, respectively. The highest protein release of 73 mg/gTS was obtained at a TS content of 2% and specific energy input of 10 kWs/gTS. The sludge disintegration efficiency declined significantly at higher TS content. Thus, there is a limiting TS concentration that could be effectively disintegrated by ultrasound, and this is governed by the capability of an ultrasonic unit in producing cavitation. The degree of disintegration also depends on types of ultrasonic unit used.

In this research the process performance of enhanced biological phosphorus removal was investigated in a sequencing batch reactor (SBR) having a new operational mode. The SBR system used in this study had simultaneous feeding and decanting conditions. The laboratory scale reactor (10 L) was operated for 392 days. The system was operated under 4 different sets each having 2 cycles per day. In each cycle, fill (4 h), anoxic (0.5 h), aerobic (7 h) and settling phases were present. In the fill phase, wastewater was fed from the bottom and the anoxic/anaerobic conditions were established in the settled sludge. During filling, the water left the system by water displacement. The system provided nitrification, denitrification as well as phosphorus and organic removal. High COD (90-98%), PO4-P (77-100%), and NH4-N (90-95%) removals were achieved by this system.