Issue 4

Water is the most important substance. Drinking water in the industry comes from raw water and is treated through a heating process. The results of laboratory tests on raw water used for drinking water are 41 MPN/100ml, so it is necessary to process raw water into drinking water using Reverse Osmosis (RO) membrane technology. The purpose of this study is to determine the difference in the decrease in the total amount of Coliform in drinking water based on variations in water pressure on the Reverse Osmosis membrane in the canteen of X Industry. This type of research is an experiment with the design used is pre-test post-test without control, the sampling technique used is grab sampling, and the total sample is 36 samples with a volume of 3600 ml. The decrease in the total number of Coliforms was analyzed using univariate and bivariate tests. The results of total Coliform in drinking water after treatment with Reverse Osmosis membranes are the average results for a pressure of 1 bar is 0 MPN/100 ml, a pressure of 1.5 bar is 2.81 MPN/100 ml, and a pressure of 2 bar is 5.3 MPN/100 ml. This study concludes that there is a difference between the pressure of 1 bar, 1.5 bar, and 2 bar on the decrease in the total Coliform content in the canteen of X Industry with a p-value of 0.001, and the most effective pressure to reduce total coliform in drinking water in the canteen of X Industry is a pressure of 1 bar with a 100% percentage. Suggestions for further research to carry out the saturated condition of the Reverse Osmosis membrane.

The Conversion of SO2 by Hydrogen Oxidation Branching Chain Reaction A.A. Arutyunyan Institute of Chemical Physics after A.B. Nalbandyan NAS of The Republic of Armenia, 5/2 Paruyr Sevak St., Yerevan 0014, Republic of Armenia E-mail: harhasmik@mail.ru The process of SО2 conversion in the hydrogen combustion mode at the following conditions T=500 oC and P<200 Torr (H2:O2:SO2:N2=10:1:1:0.5) has been studied. It is shown that at τк<4.5s the process is characterized by pulsating flames along with the consumption of hydrogen, oxygen and SО2. When leaving the reactor, free sulfur is precipitated on the cold part. The structural features of precipitated sulfur were studied with the help of electron microscopy and X- ray diffraction phase analysis. Key words: sulfur, sulfur dioxide, pulsating flames, free radicals, combustion.

Recycling of wastewater is an important issue as it is used for many important applications such as industries, agriculture, household applications and due to water scarcity across the different countries. Wastewater treatment is an important activity as it protects human being and the ecosystem from harmful and toxic elements present in wastewater. Performance evaluation of wastewater treatment technologies being complex Multi-criteria Decision Making (MCDM) problem that has contradictory evaluation factors. This paper is focused on the analysis of factors that affect evaluation of wastewater treatment technologies and their impact by developing a model which combine Analytical Hierarchy Process (AHP) and Grey Relational Analysis (GRA) for the assessment and ranking wastewater treatment technologies (WWTTs) respectively. The best WWTT is chosen based on data acquired through a case study. AHP is applied for computing criteria weights based on comparative significance while Grey Relational Analysis method is applied for ranking and selecting the wastewater treatment technologies. Sensitivity analysis is performed to show the impact of grey relational scores of alternatives in line with variations of distinguished coefficients.

This study emphasis on draining and slowing runoff volumes in arid and semi-arid lands regions using HEC-HMS model linked with various Best Management Practices (BMPs) alternatives. The proposed methods may help significantly in reducing flash flood precipitation and improving instream water quality. It provides facilities to increase flood retention times and infiltration rates. Recently, flash flooding in arid lands is occurring on almost every two-year basis and is threatening human lives and damaging properties. Modern urbanization of the cities has great impacts on flooding schemes, it increases peak streamflows and it reduces the time to peak. Eventually, major cities experienced newly developed areas to accommodate the increase of population, and thus surface runoff volumes would increase substantially. In addition to outflows from surrounding high desert lands which form a significant portion of flash flood volumes. This study proposed a modern and progressive flash flood management scheme that would emphasize on enhancing soil infiltration and runoff attenuation by construction facilities that would absorb runoff water. We formulated five proposals for flood mitigation derived from BMP techniques for the purposes of stormwater management. Rainfall-runoff natural disaster modeling was simulated using HEC-HMS (Hydrological Modeling Systems). The Geographic Information System (GIS) coupled with HEC-HMS was employed in this study to delineate the watershed line and to simulate streams discharges. Results for investigating the construction of dry dams' option showed a significant reduction in both peak volumes and time to peak and consequently, the mitigated flood spreads longer. Furthermore, downstream calculations prove the contributions of other events on increasing flood hazards downstream. Outlet bottom size and storage capacity are the major parameters that control flood hazards. Outcomes of this study would help water resources managers and decision-makers who need immediate action plans and operational responses when floods occur. Discharge outflow rates were assessed using HEC-HMS and CN methods, and modeling the studied area using Geographic Information Systems (GIS). This study reveals runoff volumes ranges of 0.04 to 0.77 cm/hr. Also, results shows that the HEC-HMS model is capable of simulating runoff based event.