Sharif Digital Repository

In this study, the biological nitrogen removal process from a wastewater with high COD and TKN concentration was investigated in a hybrid reactor. In order to remove nitrogen completely with pre-denitrification process, both moving bed biofilm system and fixed bed biofilm system with pumice stone, were used in a single reactor (volume is 16 l). Moving bed biofilm and fixed bed biofilm systems were considered in sequence, as aerobic and anoxic parts of the reactor. 35% of the aerobic volume was occupied with plastic carriers and 70% of the anoxic volume was occupied with pumice stone with an average diameter of 30mm. Experiments were done in 7 runs, for total hydraulic retention times of 30,... 

Removing nitrogen, as one the most surface and ground water contaminant is very important and in order to achieve this aim,nitrification and denitrification are effective and economical methods. In this work, moving bed biofilm reactor (MBBR) with initial denitrification structure, adapted from modified LUDZACK-ETTINGER (MLE) method used in order to industrial wastewater treatment with COD value in range of 900-2100 mg/lit and ammonium in range of 150-430 mg/lit in 3 hydrolic retention time of 18 , 12 and 8 hours.Aerobic reactor volume is 14.4 liter and anoxic reactor volume is 7.2 liter and reflux flow amount from aerobic reactor to anoxic reactor has considered being 3 times of anoxic... 

Removing nitrogen, as one of the most important contaminants of surface and ground water, needs to be considered. Since this material minimizes water quality and makes it useless. On the other hand, many industries as refineries have saline wastewater which their salinity removal is not economical by physical and chemical methods and is often impossible. Although biological treatment of saline wastewater has its problems, biological nitrification and denitrification are efficient and economical methods for nitrogen removal from industries saline wastewater. In this research, moving bed biofilm reactor (MBBR) adopted from Modified LUDZACK – ETTINGER (MLE) method has been used in order to... 

Nitrogen compounds are becoming increasingly important in wastewater management, because of the many effects that nitrogenous material can have on the environment that need nitrogen removal. In this study, the performance of a submerged fixed bed reactor in nitrogen removal, constructed two anoxic and aerobic sections under Modified Ludzack-Ettinger process was investigated. Laboratory experiments were conducted at a constant COD concentration of 350 mg/lit, hydraulic retention times of 8, 12 and 18 hours and influent ammonia loading rate between 0.128 and 0.955 g NH3/m2.day. Nitrogen removal efficiency was obtained between 80.4 and 97.3%, and COD removal efficiency was achieved between 88.9... 

Nitrogen compounds are becoming increasingly important in wastewater management. Due to several adverse effects which nitrogenous materials can have on the environment, there is a significant need for nitrogen removal. In this study, the biological nitrogen removal process from a wastewater with low COD was investigated in a submerged fixed bed reactor, constructed two anoxic and aerobic sections under Modified Ludzack-Ettinger process. Volume of each section was 10 liters. About 60% of each section was occupied with pumice stone.Experiments were conducted in 9 runs, for hydraulic retention times of 8, 6 and 4 hours, influent ammonia concentrations of 180, 90 and 30 mg/lit and recyle ratios... 

Discharging wastewater effluents to water bodies has many detrimental impacts on water quality. Thus, to prevent issues such as eutrophication and oxygen depletion, nitrogen removal is often required in wastewater treatment plants. Biological nitrification and denitrification, in comparison to physical and chemical methods, is more cost-effective and environmentally friendly, and this makes it one of the most commonly used approaches for nitrogen removal. In this work, nitrification and denitrification process and the effect of sulphate on this process is studied in a moving bed biofilm reactor (MBBR). The method used is modified LUDZACK-ETTINGER (MLE) which has an initial denitrification... 

Modeling of water quality in shallow lake is the goal of this roject.Matters cycling in environment will be explained. The dissolved Oxygen will be assigned the most important factor in water quality. The phytoplankton Growth rate and fatality rate will be modeled By LOTKAVOLTERRA equations. The nitrification by nitrifying bacteria and Michael Menton equations will be explained. Modeling will be executed By System Dynamic which feedbacks are the most com ponents of it.The model will be built with equations and coefficients in literatures and this model run by VENSIM®software. We will assure by some extreme condition tests about the structure of the model and finally we will make a... 

nowadays, due to population growth, unconventional use of water resources and on the other hand, climate change, limited renewable water resources, reduction of groundwater cavities, the need for water for agricultural use and energy production are increasing. Due to the fact that each cubic meter of dirty water pollutes 40 to 60 cubic meters of clean water and the entry of polluted effluent into the receiving sources of environmental degradation leads to a lot of wastewater treatment, water consumption management and The development of wastewater treatment processes is also becoming increasingly important. At present, wastewater treatment plants face the challenges of high energy...