تحليل و واكاوي فرآيند لجن فعال بعنوان متداولترين سيستم هاي رشد معلق در تصفيه فاضلاب

Analysis of activated sludge process as the most common suspended-growth systems in wastewater treatment

ﻫﺪف اﺻﻠﯽ ﺗﺼﻔﯿﻪ ﻓﺎﺿﻼب ﺑﻮﺳﯿﻠﻪ ﻓﺮآﯾﻨﺪ واﺣﺪ ﺑﯿﻮﻟﻮژﯾﮑﯽ، ﺣﺬف ﻣﻮاد آﻟﯽ ﻣﺤﻠﻮل ﯾﺎ ﮐﻠﻮﺋﯿﺪي ﻣﻮﺟﻮد در ﻓﺎﺿﻼب ﺑﻪ ﻣﺤﺼﻮﻻت دﯾﮕﺮ ﺗﻮﺳﻂ ﻣﯿﮑﺮوارﮔﺎﻧﯿﺴﻢ ﻫﺎ و ﯾﺎ ﮐﺎﻫﺶ ﻣﻮاد ﻣﻐﺬي1 ﻧﯿﺘﺮوژن و ﻓﺴﻔﺮ، ﻓﻠﺰات ﺳﻨﮕﯿﻦ و .... ﻣﯽ ﺑﺎﺷﺪ. ﻓﺮآﯾﻨﺪ ﻟﺠﻦ ﻓﻌﺎل ﻣﻬﻤﺘﺮﯾﻦ ﻓﺮآﯾﻨﺪ واﺣﺪ ﺑﯿﻮﻟﻮژﯾﮑﯽ ﻣﯽ ﺑﺎﺷﺪ ﮐﻪ ﻋﻤﻮﻣﺎ ﺑﺮاي ﺗﺼﻔﯿﻪ ﺧﺎﻧﻪ ﻫﺎي ﺑﺰرگ و ﻣﺘﻮﺳﻂ ﺑﮑﺎر ﮔﺮﻓﺘﻪ ﻣﯽ ﺷﻮد. ﺑﺎ ﺗﻮﺟﻪ ﺑﻪ اﻫﻤﯿﺖ ﻣﻮﺿﻮع ﻫﺪف اﯾﻦ ﻣﻘﺎﻟﻪ ﺗﺤﻠﯿﻞ و واﮐﺎوي ﻓﺮآﯾﻨﺪ ﻟﺠﻦ ﻓﻌﺎل ﺑﻪ ﻋﻨﻮان ﻣﺘﺪاول ﺗﺮﯾﻦ ﺳﯿﺴﺘﻢ ﻫﺎي رﺷﺪ ﻣﻌﻠﻖ در ﺗﺼﻔﯿﻪ ﻓﺎﺿﻼب اﺳﺖ. ﺑﻪ ﻣﻨﻈﻮر ﺗﺤﻘﻖ ﻫﺪف ﺗﺤﻘﯿﻖ از روش ﮐﺘﺎﺑﺨﺎﻧﻪ اي و اﺑﺰار ﻓﯿﺶ ﺑﺮداري اﺳﺘﻔﺎده ﺷﺪ. در اﯾﻦ ﻣﻘﺎﻟﻪ ﻓﺮآﯾﻨﺪ ﻟﺠﻦ ﻓﻌﺎل، ﺗﺠﺰﯾﻪ ﺑﯿﻮﻟﻮژﯾﮑﯽ در ﻓﺮآﯾﻨﺪ ﻫﻮازي، اﻧﻮاع ﺳﯿﺴﺘﻢ ﻫﺎي ﻫﻮازي، رژﯾﻢ اﺧﺘﻼط، ﻓﺮآﯾﻨﺪ ﻟﺠﻦ ﻓﻌﺎل ﺑﺎ اﺧﺘﻼط ﮐﺎﻣﻞ، ﻣﺘﻐﯿﺮﻫﺎي ﻓﺮآﯾﻨﺪ ﻟﺠﻦ ﻓﻌﺎل ﺑﺎ اﺧﺘﻼط ﮐﺎﻣﻞ، ﻣﺘﻐﯿﺮﻫﺎي اﺻﻠﯽ ﻓﺮآﯾﻨﺪ ﻟﺠﻦ ﻓﻌﺎل، درﺟﻪ ﺣﺮارت، ﻧﺴﺒﺖ ﻟﺠﻦ ﺑﺮﮔﺸﺘﯽ و ﻧﯿﺘﺮﯾﻔﯿﮑﺎﺳﯿﻮن و دﻧﯿﺘﺮﯾﻔﯿﮑﺎﺳﯿﻮن ﻣﻮرد ﺑﺮرﺳﯽ ﻗﺮار ﮔﺮﻓﺖ. ﺑﺮرﺳﯽ ﻫﺎ ﻧﺸﺎن داد؛ در ﮔﺬﺷﺘﻪ ﻃﺮاﺣﯽ ﻓﺮآﯾﻨﺪ ﻟﺠﻦ ﻓﻌﺎل ﺑﺮ ﭘﺎﯾﻪ ﻣﺘﻐﯿﺮﻫﺎي ﺗﺠﺮﺑﯽ ﮐﻪ از ﻧﻤﻮﻧﻪ ﻫﺎي ﺳﺎﺧﺘﻪ ﺷﺪه واﻗﻌﯽ ﺑﺪﺳﺖ ﻣﯽ آﻣﺪ، اﻧﺠﺎم ﻣﯽ ﮔﺮﻓﺖ و ﻟﯿﮑﻦ در ﺣﺎل ﺣﺎﺿﺮ ﻃﺮاﺣﯽ ﺑﺮ ﭘﺎﯾﻪ رواﺑﻂ ﺳﯿﻨﺘﯿﮏ ﺑﯿﻮﻟﻮژﯾﮑﯽ ﺣﺎﮐﻢ ﺑﺮ ﻓﺮآﯾﻨﺪ ﺗﺼﻔﯿﻪ ﻣﯽ ﺑﺎﺷﺪ. اﯾﻦ رواﺑﻂ ﺳﺮﻋﺖ رﺷﺪ ﺑﯿﻮﻟﻮژﯾﮑﯽ و ﻣﺼﺮف ﻣﻮاد آﻟﯽ را ﺑﻮﺳﯿﻠﻪ ﺿﺮاﯾﺐ ﺳﯿﻨﺘﯿﮏ ﺑﯿﻮﻟﻮژﯾﮑﯽ و ﻧﺴﺒﺖ ﻏﺬا ﺑﻪ ﻣﯿﮑﺮو ارﮔﺎﻧﯿﺴﻢ ، ﻋﻤﺮ ﻟﺠﻦ و ﻏﯿﺮه ﺑﯿﺎن ﻣﯽ ﮐﻨﺪ. ﻓﺮآﯾﻨﺪ USBF ﯾﮏ ﻓﺮآﯾﻨﺪ ﺳﯿﺴﺘﻢ ﻟﺠﻦ ﻓﻌﺎل ﻣﺘﻌﺎرف ﻣﯽ ﺑﺎﺷﺪ ﮐﻪ ﺑﺎ ﯾﮏ ﻣﻨﻄﻘﻪ ﻏﯿﺮ ﻫﻮازي و ﯾﮏ زﻻل ﺳﺎز ﺗﺮﮐﯿﺐ ﺷﺪه و در ﯾﮏ ﺑﯿﻮراﮐﺘﻮر ﻗﺮار داده ﺷﺪه اﻧﺪ. اﯾﻦ ﻓﺮآﯾﻨﺪ ﯾﮏ ﺳﯿﺴﺘﻢ ﮐﺎرآﻣﺪ ﺟﻬﺖ ﺗﺼﻔﯿﻪ اﻧﻮاع ﻓﺎﺿﻼﺑﻬﺎي ﻣﺴﮑﻮﻧﯽ، ﺑﻬﺪاﺷﺘﯽ، ﺻﻨﻌﺘﯽ، ﺻﻨﺎﯾﻊ ﻏﺬاﯾﯽ و ﮐﺸﺎورزي ﻣﯽ ﺑﺎﺷﺪ.

The main objective of wastewater treatment by the process of biological unit is the removal of soluble organic matter in colloidal in wastewater to other products by microorganisms or reduce nutrients (nitrogen and phosphorus), heavy metals etc. Activated sludge process is the most important process of biological unit that is used primarily for large and medium refineries. Considering the importance of the aim of this article, analysis of activated sludge process is as the most common suspended -growth systems in wastewater treatment. In order to achieve the purpose of research, library and note taking tool was used. In this process, the process of activated sludge, biodegradation in aerobic process, different systems of aerobic, mixing diet, the process of activated sludge with complete mixing, variables of activated sludge process with complete mixing, the main variables of the activated sludge process, the temperature, the ratio of returned sludge and nitrification and denitrification was investigated. The survey showed that, in the past, designing the process of activated sludge was done based on experimental variables that were obtained from real samples made, but now the design is based on kinetic biological equations governing the treatment process. The relationship indicates biological growth rate and consumption of organic matter by biological kinetics factors and the ratio of food to micro-organisms, sludge age and so on. USBF process is a conventional activated sludge process that with an anaerobic zone and a clarifier is combined and placed in a bioreactor. This process is an efficient system for the treatment of residential wastewater, health, industry, food industry and agriculture.