英文 菌胶团

The role of zoogloea in sewage treatment research present situationand the developmentKuang Jiawei1,Miu Qinsong1,Jiang Chongyang1(1.Xuzhou Institute of Environmental Engineering)Abstract：Nowadays, and its derivatives modified by activated sludge process is the most widely used method of dealing with urban sewage It can remove soluble and colloidal state from sewage to biochemical organic matter and suspended solids which can be activated sludge adsorption activated sludge process and some other substances in activated sludge as the main body of the main method of wastewater biological treatment zoogloea is an important part of activated sludge This paper analyzes the zoogloea role in wastewater treatment, and the future research direction Key Words:Activated sludge process;sewage treatment;zoogloeaWater shortage and pollution is one of the world is facing environmental problems, how to protect the water resources, how to deal with the polluted water, sewage harmless sewage treatment method with physical method, chemical method and biological method Is the most widely used biological method, its advantage is simple rate high cost low activated sludge process is the use of aerobic activated sludge microorganism, under the condition of ventilation, the sewage purification method of biology This method is one of the main current organic wastewater treatment method It is the use of certain microorganisms grow in zoogloea to the larger surface area in the process of a large number of flocculation and adsorption of organic matter, sewage and under the action of oxygen, the assimilation the matter to the composition of bacteria, or break it down into CO2 materials such as water, so as to achieve the aim of reducing organic pollutants in wastewater, and zooglea is live.1.The concept of zoogloeaBecause of their genetic characteristics determine , some bacteria among certain bacteria stick to each other arrangement set together, are surrounded by a common bacterial capsular form a certain shape group ,which are called floc . It is the activated sludge floc and drops main component of the mucous membrane filter . The bacterial zoogloea which embedded in the gum , and it is not easy to be swallowed by protozoa , which is in favour of settlement . There zoogloea typical genus , which has two kinds : dendritic zoogloea genus and vertical ( suspended ) filamentous zoogloea genus . The reason is that some bacteria under certain environmental conditions mucinous material layer may be formed to surround the outside of the cell wall . This layer of substance is called mucus layer . Mucus layer thickness is not necessarily. Its composition is mainly polysaccharides and pectin substances . Formation of mucus is a normal result of bacterial metabolism , but mucous layer has nothing to do with the growth of bacterial slime . When bacteria movement , mucus from the cell surface may peel off . When bacteria move , mucus will separate from the cell surface .Whenthe mucus layer of uniform thickness is called capsular . Capsular thickness is 0.5 ~ 2.0nm, and micro- capsular thickness is 5 ~ 10nm. In normal circumstances, the capsule will not be split after the bacteria is to make them stick together . However, some bacteria’s mucus layer can be bonded together to make a lumpy growth of many bacteria . These bacteria clumps is zoogloea.2.the function of zoogloeaZoogloea that has the strong ability of adsorption and oxidation of organic matter is an important part of activated sludge and biological membrane,which plays an important role in The biological treatment .Zoogloea that has adsorption and decomposition of organic matter provide protozoa and tiny metazoan with a good living environment .Zoogloea bacteria is hidden in the colloidal substance.On the one hand, it not only protects from animal , but also enhances its ability to resist the bad environment .On the other hand,it also can have instructed effect.the performance of activated sludge is good or bad, mainly according to the content of zoogloea color , size and structure of the close degree to determine [2].Zoogloea is located at the center of the structure and function of activated sludge and is a basic component of activated sludge.Once the zoogloea is damaged, activated sludge removal rate of organic matter will significantly decreased or lost.3.The current research status of zoogloea3.1The specific form of zoogloeaDifferent zoogloea bacteria can form different shapes, and has dichotomous,vertical,filamentous,spherical,oval, mushroom-shaped ,flake and all kinds of irregular shape. Not all can form zoogloea bacteria. The main species is zoogloea and shows a rod .Young fungus bacteria have the the raw flagella and lively movement, under certain conditions,and can form a layer of mucus surrounded on the outside of the cell wall, which can be gathered into hairy zoogloea that is gram negative and do not produce spores and belong to requiring oxidation heterotrophic bacteria [3-4].When zoogloea that has rules in the shape of branches extends outward and grows,it is not only to attract free bacteria making a large number of reducing, but also to make the original scattered with status of sludge flocs connect and grow into larger flocs that play a role in connecting bridging.Choosing zoogloea dendritic body top to observe, on continuous observation for 15 minutes, we can observe that near the vertex continuously gathered many rapid vibration of free zoogloea .since it has a thick capsule, making a single lever zoogloea present ovoid under the microscope .Dynamic adhesive bacteria’s dendritic the adhesion behavior shows vertical link at the top, namely to ovoid tip towards growing point glue,which makes the most of the dynamic adhesive bacteria of dendritic body are arranged end to end .Therefore, only the top is exposed connection point. This is the reason zoogloea showed growth of filamentous extensions.From the point of view of energyconsumption analysis, Zoogloea with oval top phase, small adhesion surface, the connection speed, small energy consumption, easily growing fast, play groups a competitive advantage.3.2The growth of zoogloea influencing factorsThe growth of zoogloea is influenced by many factors, forming micelles bacteria is the key to improve the effect of wastewater treatment and its running stability [5]. Therefore, to explore zoogloea growth conditions is particularly important. A bacterial strain under suitable environmental conditions forms a floc structure, but when encountered undesirable environment, zoogloea loose floc occurs, even showing a single bacteria, which affects the treatment effect. Therefore, in order to achieve better treatment effect, requiring zoogloea compact structure, adsorption, good settling properties. It must meet the nutritional zoogloea bacteria and environmental requirements. Zoogloea’s forming dendritic zoogloea, the first condition is dirty residence time, which is the sludge age. In biological wastewater treatment, compared with other forms of microorganisms, micelle-forming bacteria grow slower, longer sludge age. Secondly, Zoogloea is suitable for aerobic environment [6],and is linked to the dissolved oxygen in the water .4.Future study direction of zoogloeaBecause our country’s most of the rivers are polluted by organic,activated sludge process with application of biased efficiency, flexibility, run continuously, automation,technology function diversity can remove nitrogen and phosphorus. Activated sludge is from sewage domestication.nematodes and rotifers show that the sludge has been mature .In the activated sludge, microbial community is mainly including bacteria, protozoa and algae .The bacteria and protozoa are the main two kinds .In the biological wastewater treatment systems, the degradation of pollutants is mainly bacteria.In the activated sludge of wastewater biological treatment, activated sludge bacteria in the degradation of organic matter in water purification plays a most important ually,bacteria is divided into two categories, one is filamentous bacteria, another it is zoogloea .So it is particularly important to study zoogloea.Filamentous bacteria in activated sludge flocculation body form a space truss structure, zoogloea bacteria attached on the formation of a symbiotic relationship between microbial ecological system, when the zoogloea bacteria and filamentous bacteria are on a balance of an appropriate proportion to grow, the sludge flocs formed by large and dense is easy to precipitate. as the growth of filamentous bacteria is faster than zoogloea bacteria, there will be a sewage sludge expansion. Activated sludge expansion is since the advent of activated sludge process has been accompanied by a worldwide difficult problem.Although researchers through a lot of research guided by the biodynamics and comprehensive research results put forward the cause of sludge bulking and classification of the unity of theory and effectivecontrol method, as a result of filamentous bacteria related to the activated sludge expansion type is various, combined with a series of complicated environment and operating factors influence each other,having been the expansion of the proposed control method can't satisfy all control in activated sludge expansion.In the activated sludge expansion, sludge bulking caused by filamentous bacteria multiply is more common. Controlling sludge bulking and strengthening the competitiveness of zooglea and filamentous fungi has become a zoogloea research direction in the future. 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