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Background: Data mining [DM] is an approach used in extracting valuable information from environmental processes. This research depicts a DM approach used in extracting some information from influent and effluent wastewater characteristic data of a waste stabilization pond [WSP] in Birjand, a city in Eastern Iran
Methods: Multiple regression [MR] and neural network [NN] models were examined using influent characteristics [pH, Biochemical oxygen demand [BOD[5]], temperature, chemical oxygen demand [COD], total suspended solids [TSS], total dissolved solid [TDS], electrical conductivity [EC] and turbidity] as the regression input vectors. Models were adjusted to input attributes, effluent BOD[5] [BODout] and COD [CODout]. The models performances were estimated by 10-fold external cross-validation. An internal 5-fold cross-validation was also used for the training data set in NN model. The models were compared using regression error characteristic [REC] plot and other statistical measures such as relative absolute error [RAE]. Sensitivity analysis was also applied to extract useful knowledge from NN model
Results: NN models [with RAE = 78.71 +/- 1.16 for BODout and 83.67 +/- 1.35 for CODout] and MR models [with RAE = 84.40% +/- 1.07 for BODout and 88.07 +/- 0.80 for CODout] indicate different performances and the former was better [P < 0.05] for the prediction of both effluent BOD5 and COD parameters. For the prediction of CODout the NN model with hidden layer size [H] = 4 and decay factor = 0.75 +/- 0.03 presented the best predictive results. For BODout the H and decay factor were found to be 4 and 0.73 +/- 0.03, respectively. TDS was found as the most descriptive influent wastewater characteristics for the prediction of the WSP performance. The REC plots confirmed the NN model performance superiority for both BOD and COD effluent prediction
Conclusion: Modeling the performance of WSP systems using NN models along with sensitivity analysis can offer better understanding on exploring the most significant parameters for the prediction of system performance. The findings of this study could build the foundation for prospective work on the characterization of WSP operations and optimization of their performances with a view to conducting statistical approaches
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Background: Chlorophenols are classified as priority toxic pollutants. These acidic organic compounds present a serious potential hazard for human health and aquatic life. Chlorophenols accumulate in water, soil and air due to high stability, and impart an unpleasant taste and odor to drinking water and can exert negative effects on different biological processes. Among the different methods of removal, adsorption process by low price adsorbents, such as fly ash [FA] is common. Therefore, in this study, the effects of oxidation of FA as modified adsorbent were investigated when the adsorption of 2-chlorophenol [2-CP] was increased
Methods: This experimental study was conducted from March to September of 2013. FA obtained from Zarand power plant [located in Kerman province] was oxidized with potassium permanganate. Effective factors on the oxidation of FA, such as temperature, oxidation time and concentrations of oxidizers were optimized. Raw sewage of Zarand coal washing plant was tested under optimal conditions. All tests were carried out according to the standard methods book for the examination of water and wastewater
Results: Optimal condition for the preparation of oxidized FA was obtained at 70 degree C, 1 hour, and 1 mM of potassium permanganate concentration. The absorber obtained was able to remove 96.22% of 2-CP under optimized conditions [pH=3, 2 hours, adsorbent dose 0.8 g and room temperature]. The removal efficiency of the real wastewater under optimal conditions was 82.1%
Conclusion: Oxidized FA can be used for the removal of this pollutant from industry wastewater due to its high efficiency of removal in real wastewater, it is easy and inexpensive to prepare and could modify the sorbent
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The aim of the present study was to evaluate the capability of helminths to absorb heavy metals in comparison with that of the host tissues. We compared the concentration of cadmium [Cd] and chromium [Cr] in urban rats and in their harboring helminthes -Moniliformis moniliformis, Hymenolepis diminuta and larval stage of Taenia taenaeiformis [Cysticercus fasciolaris]. The heavy metal absorption was evaluated in 1g wet weight of parasites and tissues digested in nitric acid, using Inductivity Coupled Plasma [ICP-OES]. A higher concentration of heavy metals was revealed in the helminths than in the host tissues. Bioconcentration factor [BF= C in parasite/C in tissue] for both Cd and Cr absorption was more than 10-fold higher in M. moniliformis than in the three compared host tissues. The BF of Cd in M. moniliformis compared to the liver, kidney and muscle of the host was 9.16, 14.14 and 17.09, respectively. BF in Cr in the same parasite and the same host tissues ranged from 10.67, 7.06 and 4.6. High level of absorption in H. diminuta was significantly likewise; the individual BF of Cd and Cr in H. diminuta compared to the liver, kidney and muscle of the hosts was 4.95, 5.94 and 4.67 vs. 2.67, 11.56 and 5.59. The mean concentration of Cd and Cr in C. fasciolaris was also significantly higher than that in the rat livers [P<0.007 and P<0.004, respectively]. This study claims that parasites of terrestrial animals exposed to heavy metals can be more accurate indicators than the host tissues as new environmental monitoring agents
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Outbreaks of legionellosis may be a side effect of institution-water treatment. However, the long-term outcomes and the predictive factors of Legionella prevalence in such systems have still not been fully studied. This study was therefore conducted to investigate the prevalence of Legionella spp. and to evaluate the role of bacteriological water quality parameters on its prevalence and removal in hospital water systems. A total of 45 samples were collected from distinct sites at seven hospitals in Tehran, Iran. The prevalence of this bacterium was assayed through a sensitive and specific technique for DNA detection using PCR. Multivariable stepwise regression analysis was used to explore the independent effects of the baseline factors on the incidence of Legionella. Two positive samples were also identified for species by DNA sequencing. Legionella were detected in 31.1% of samples. Showerheads and cold-water taps were the most and the least contaminated sources with 55.3 and 9 percent positive samples, respectively. Total mean of residual chlorine was 0.38 mg/L, with the peak value of 1.7 mg/L. Legionella detection was proportional to the residual chlorine content of water and the results indicated that residual chlorine content is a critical factor in the incidence and proliferation of Legionella [r=-0.33]. The prevalence of Legionella also coincided with the prevalence of HPC and amoeba cysts. The high positive rate of Legionella colonization shows that hospital-acquired legionellosis might be under diagnosed in studied hospitals. Further, Legionella colonization is independent of the type of water, system characteristics and of preventive maintenance measures
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Anaerobic treatment methods are more suitable for the treatment of concentrated wastewater streams, offer lower operating costs, the production of usable biogas product. The aim of this study was to investigate the performance of an Anaerobic Fluidized Bed Reactor [AFBR] - Aerobic Moving Bed Bio Reactor [MBBR] in series arrangement to treat Currant wastewater. The bed materials of AFBR were cylindrical particles made of PVC with a diameter of 2-2.3 mm, particle density of 1250 kg/m[3]. The volume of all bed materials was 1.7 liter which expanded to 2.46 liters in fluidized situation. In MBBR, support media was composed of 1.5 liters Bee-Cell 2000 having porosity of 87% and specific surface area of 650m[2]/ m[3]. When system operated at 35 [degree sign] C, chemical oxygen demand [COD] removal efficiencies were achieved to 98% and 81.6% for organic loading rates [OLR] of 9.4 and 24.2 g COD/ l.d, and hydraulic retention times [HRT] of 48 and 18 h, in average COD concentration feeding of 18.4 g/l, respectively. The contribution of AFBR in total COD removal efficiency at an organic loading rate [OLR] of 9.4 g COD/ l.d was 95%, and gradually decreased to 76.5% in OLR of 24.2 g COD/ l.d. Also with increasing in organic loading rate the contribution of aerobic reactor in removing COD gradually decreased. In this system, the anaerobic reactor played the most important role in the removal of COD, and the aerobic MBBR was actually needed to polish the anaerobic treated wastewater
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Reactores Biológicos , Análisis de la Demanda Biológica de OxígenoRESUMEN
Iran's health system is expanding the disaster and emergency higher education programs over the country to enhance the capacity of human resources for effective and efficient disaster mitigation, preparedness, response and recovery. In this article we present an overview about the initiatives and progress of disaster and emergency health higher education in Iran. Following the Bam earthquake, in collaboration with the Ministry of Health and Medical Education and National Institute of Health Research, School of Public Health at the Tehran University of Medical Sciences, Iran took the initiative to develop a Master of Public Health [MPH] with disaster concentration in 2006, a PhD in disaster and emergency health in 2011, and a well constructed certificate course in 2008 entitled Disaster Health Management and Risk Reduction [DHMR]. Iran, Kerman and Shahid Beheshti Universities of Medical Sciences and University of Social Welfare and Rehabilitation are other academia that joined this initiative. Regarding the importance of programs evaluation, we have planned for a comprehensive evaluation of MPH and DHMR programs in 2013-4 and the Accreditation and Evaluation Board of Disaster and Emergency Health, based in MOH and ME, is responsible for evaluation of the PhD program in 3-5 years from initiation