in the present study, photocatalytic removal of p-nitrophenol has been carried out in the presence of zno by using a batch reactor with a uv-c lamp (15 w). the effects of applied zno concentration and uv light intensity have been studied. the increase of initial pollutant concentration decreases the removal rate, and the results indicate that the apparent reaction rate constant in the uv/zno pr...

in this study two identical anaerobic completely mixed fluidized bed reactors with gac and sand media were employed for cod & phenol removal. at loading rate of 1.6 g phenol l-1d-1, the efficiency of phenol removal in gac & sand reactors were 97.7% & 74%, respectively. at high loading rate of phenol (6.09 g phenol i: 1d1) the efficiency of phenol removal in gac reactor was better than 95%. in g...

In this research, an experimental study to evaluate nutrient removal from synthetic wastewater by a lab-scale moving bed biofilm process was investigated. Also, kinetic analysis of the process with regard to phosphorus and nitrogen removal was studied with different mathematical models. For nutrient removal, the moving bed biofilm process was applied in series with anaerobic, anoxic and aerobic...

background: contamination of water with arsenic has attracted the researchers’ attention as a global problem in recent years and has been observed in some parts of iran. the purpose of this study is to assess the efficiency of welding iron waste in removing arsenic from aqueous solutions.   methods: in this study, the effects of different parameters, such as ph (3-9), initial concentration of a...

One of the key issues in the design of personal communication service (PCS) systems is the efficient management of location information. The current IS-41 and GSM schemes use a two-tier system of home location register (HLR) and visitor location register (VLR) databases. In a two-tier system, the success of a call requires the HLR and the callee’s current VLR to be failure-free. A VLR failure a...

this study investigates removing ash and pyrite sulphur from bitumen by column flotation process. central composite design (ccd) of response surface methodology (rsm) was applied for modeling and optimization of the percentage of ash and pyrite sulphur removal from bitumen. the effects of five parameters namely the amounts of collector and frother agents, particle size, wash water rate and feed...