Volume 2 Issue 4

Authors: Ayad S. Mustufa; Sadeq O. Sulaiman; Marwa Y. Khudair

Abstract: Field experimental work was carried out at the College of Agriculture, University of Anbar, Iraq, for the period from 15/1/2012 to 15/5/2012 using phosphate and gypsum rocks bio-filters to determine the impact on the purification of the sewage by analyzing parameters EC, TDS, Cations (Mg+2, Na+, K+) and anions (HCO3¯ and Cl¯). Two trenches were designed with dimension of (20 m long and 6 m wide) nearby a wastewater tank. Then samples were taken from the inlet and outlet, the water was withdrawn from the bio-filteration system and then repeated the filling and emptying process again. Results showed a significant decrease in the value of EC, TDS Cations (Mg+2, Na+, K+) and anions (HCO3¯ and Cl¯) concentrations for phosphate bio-filters compared to gypsum bio-filters.

Keywords: Wastewater; Biofilteration; Phosphate; Gypsum; Adsorption; TDS; EC


Authors: Jerzy W. Mietelski; Krzysztof Kleszcz; Edyta ?okas; Stanis?aw Walas; Halina Mrowiec; Anna Tobiasz

Abstract: 99Tc is a long lived radionuclide, a fission product and decay product of its short lived isomer 99mTc widely used in nuclear medicine. Although past releases to environment are much higher than present input from nuclear medicine, the latest comes at certain input places. Presented are results of 99Tc measurements in Vistula River bottom sediments upstream and downstream to Warsaw, similar downstream to Kraków and two samples of solid wastes from Krakow sewage purification station. Results showed large spread of activity concentration. The maximum 99Tc activity concentration was detected in sample taken near Kraków (13.4±4.0 Bq/kg). The second highest 99Tc value was found in one sample downstream Warsaw, which was 6.8±2.3 Bq/kg. The sewage dry waste has 99Tc at about 30 times lower activity concentration, close to 0.4 Bq/kg. However, the latest results prove that 99Tc from medical application can be detected at least in some kind of environmental samples.

Keywords: Nuclear Medicine; Environmental Radioactivity; Technetium; Liquid Scintillation Spectrometry; Mass Spectrometry


Authors: Thewodros G. Mamo; Ilan Juran; Isam Shahrour

Abstract: Municipal water network systems are composed of a wide range of complex buried infrastructure. Many of these essential infrastructures have reached or exceeded their design life cycle and need a sound rehabilitation and replacement (R&R) Maintenance Strategies. However, maintaining and repairing such an aging and complex water pipeline network systems in big urban cities presents a unique decision and management challenges for water utility companies with respect to how to carry out the ranking and evaluation process and decide which of these complex wide ranges of buried infrastructure from the networks required replacement or rehabilitation in a cost-effective manner. These decision and management challenges of maintaining water distribution pipeline network infrastructures at nearly the intended design condition by investing the minimum amount of money, and allocating limited resources utility companies have among different projects kept the water utility companies actively searching for innovative approaches for decision support methodologies based on analysis of options, that involves evaluation of many criteria and parameters in order to determine the optimal maintenance strategies. This paper presents how risk based Fuzzy Analytic Hierarchy Process (FAHP) decision approach can be used to rank existing or recently detected multiple leakages form WD pipeline networks. It also demonstrate how this method can benefit the decision making process for the selection of which pipeline required urgent action, and prioritize the optimal alternative rehabilitation and replacement (R&R) Maintenance Strategies by integrating value professional judgments and stakeholder preferences with limited annual budget the water utility companies may have. In conclusion, this FAHP approach would benefit the decision-makers of water utility companies where there are currently no structured approach or methods for making a responsible and defendable decision with clearly demonstrated trade-offs between stakeholder investment and water utility agencies service levels standards and objectives.

Keywords: Multi-Criteria Decision support (MCDS); FAHP Model; Urban Infrastructure; Rehabilitation and Replacement (R&R); Leakage; Asset Management


Authors: Do Hoai Nam; Nguyen Quoc Dung; Keiko Udo; Akira Mano

Abstract: The combined effect of low river flow in dry seasons and sea level rise tends to enhance saline concentration in estuaries. This study presents the assessment of inland salinity intrusion in the future climate (2075-2099) based on super-high resolution climate model output and sea level rise estimates under the emission scenario A1B. A simple correction method (scaling factor) is applied to correct the climate model output for the estimates of future rainfall in dry seasons which are then used as input for a coupled hydrological-hydraulic model to perform hydrodynamic and saline concentration analyses in the estuaries of the Vu Gia - Thu Bon River basin in Central Vietnam. Results show that sea level rise is found the dominant cause of increases in saline concentration in the estuaries; while the effect of streamflow declination is not really significant due to the nature of the estuaries where river beds are quite steep in upstream portions which diminish the propagation of backwater effect. The future saline concentration is likely to increase in a range from 20% to 60% relative to the present-day (1979-2003) climate in response to sea level rise scenarios (low to high) derived from a multi-model simulation.

Keywords: Super-High Resolution Climate Model; Low Streamflow; Sea Level Rise; Salinity Intrusion


Authors: Diogo Robl; Patricia R. Dalzoto; Marcos A. C. Berton; Vania A. Vicente; Ida C. Pimentel; Paulo R. D. Marangoni

Abstract: The Balbina Hydroelectric Power Station is located in the central Brazilian Amazon Forest and is vulnerable to biofouling and biofilm formation on immersed metal surfaces because of the high ambient temperature near equatorial line. Microbiologically influenced corrosion (MIC) comprises organic and inorganic processes that occur simultaneously or separately and enhance the harmful effects of the dissolution of metal surfaces. Several types of microorganisms are involved in this process, and microbial colonisation of surfaces through biofilm maturation leads to biocorrosion. Each stage of MIC has characteristic microorganisms, and the present study aimed to characterise the different microorganisms found in samples collected from carbon steel, stainless steel, and copper alloy coupons exposed to the water reservoir of the Balbina Hydroelectric Power Station. Microorganisms described in the literature as important for MIC were detected using microbiological tests and molecular tools. In Brazil, 72% of the energy-based power generation is derived from hydropower plants; hence, it is important to study the origin of corrosion on metallic surfaces exposed to the water of the reservoir.

Keywords: Biofilm; Amazon Biodiversity; Biocorrosion; Biofouling