一般污泥和含油污泥的处理方法（中英文）

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一般污泥和含油污泥的处理方法
一般来讲，为了不造成环境的二次污染，需要在污水处理的二级处理之后添加一道污泥处理工艺。污水处理的目标通过把水中杂质浓缩成固体形态再从流体中分离而实现。这种浓缩质变称为污泥，因包含了大量的有害物质，需要妥善处置。污泥处理设备大约占污水处理厂的40%-60%基建投资，污泥处理则占50%左右的处理费用，同时也造成了和其经济费用不成比例的处理难度。
首先，原污泥通过污泥泵由二沉池打到另一个池子中从而和上清液分离。因为原污泥的含水率通常能达到99.5%，所以污泥必须浓缩，有多种可行的方法用于减少污泥的体积。例如真空过滤和离心等机械处理的方法通常用于将污泥以半固体形式处置之前。通常这些方法是污泥焚烧处理的准备工作。如果计划采用生物处理，则多数才用重力沉降或者是气浮的方法进行浓缩。这两种情况所对应的污泥仍然是流态的。
重力浓缩池的设计和运行类似于污水处理中的二沉池。浓缩功能是主要的设计参数，为了满足更大的浓缩能力，浓缩池基本上比二沉池要深。一个设计正确，运行良好的重力浓缩池至少能提高两倍的污泥含泥量。也就是说，污泥的含水率可以有99.5%减少到98%，或者更少。这里值得一提的是，重力浓缩池的的设计要尽量基于中式结果的分析，因为合适的污泥负荷率与污泥的属性的有很大关系的。
如果采用溶气气浮浓缩，需要有一小部分的水，通常是二沉池出水，在400kPa的压力下充气。这种过饱和的液体通入罐底，而污泥在大气压下通过。气体以小气泡的形式和污泥中的固体颗粒黏附，或则是被包围，从而带动固体颗粒上浮到表面。浓缩了的污泥的上部被除去，而液体由底部流回溶气罐充气。
体积减少后，污泥中含有大量的有害成分，在处置之前需要将之转化为惰性成分。最常用的方法是生物降解稳定。因为这个过程目的在于将物质转化为最终无菌产物，所以常应用消化的方法。污泥消化既能进一步的减少污泥体积也能使所含固体转化为惰性物质并且大体的上没有病菌。通过厌氧消化或好养消化都能达到污泥消化目的。
污泥含有多种有机物，因此需要多种微生物来分解。有关资料将厌氧消化中的微生物分为两类：产酸菌和甲烷菌。所以，我们也能把厌氧消化分为两步。第一步，由兼性厌氧菌和厌氧菌组成的产酸菌通过水解作用溶解有机固体。接着溶解质由发酵作用转化为酒精和低分子量分子。第二步，有严格厌氧菌组成的甲烷菌将乙酸、酒精、水和二氧化碳转化为甲烷。因为两种菌群只能在无氧的环境下存活，所以厌氧消化的反应器必须是密闭的。设计容器的时候同时也要考虑另外的一些因素，例如：温度、pH值和混合物搅拌。
污泥也可以通过好氧消化稳定。这种消化基本上只能用于可生化污泥而不能用于初沉池污泥，伴随着二沉池和污泥浓缩池中污泥体积的减少，这个工艺需要不断的鼓气。好氧消化多应用于深度曝气系统。再者，好氧消化对环境条件不敏感，也不局限有流行变化。
污泥消化以后，污泥中的有机物能被去除并且能进一步的减少污泥体积。接下来，污泥需要处置。多种方法可以用来有效的处置污泥。其中包括焚烧、卫生填埋和用作化肥以及土壤改良剂。原污泥可以用来焚烧，可以有效地减少含水率。添加燃料可以用来引起和维持燃烧，城市垃圾也可能用来达到这个目标。原污泥和消化污泥也可以用卫生填埋来处置。污泥的土地应用实践了好几年，而现在只限于处理消化污泥。污泥的营养成分有利于植物成长，而其颗粒特性可用于土地改良。这些应用局限有饲料作物和非人类消费，而运用于支持可食用植物的可能性正在研究中。污泥土地应用的主要限制因素为植物富集金属毒性和水体富营养污染。污泥的应用可通过在流态时由喷淋器喷淋、沟渠导流或直接注入土壤。去水污泥可以由传统农用机械铺设在土地之上在和培养土壤。
上述文字指的是一般污泥的处理。因为污泥能造成环境的污染，所以我们需要尽最大的努力使之无害化。现在，很多导致类型污染的具有不同特性污泥正在研究中。在本文中，我将叙述一种来自于人类产油和石油工业的污泥，这个代表性污泥称之为含油污泥。
大量的污泥产生，而这种污泥中含有相当大量的油，必须在最终处置之前将之去除。炼油厂产生的污泥不能被安全的处置，除非将其含油量去除到一定程度。此外，在炼油厂的油水分离系统和储油罐中因为含油原料的累积而产生的污泥的处理费用很高，并且对环境造成很严重的污染。石油是一种疏水混合物例如：烷烃，芳香烃，树脂和沥青。许多化合物是有毒性的，致突变的和致癌的。它们的排放的受到严格控制的，因为它们对人体健康和环境的负面影响，它们被美国环保部门分类并列为环境污染物优先。
有很多种方法可以用来处理含油污泥。化学和物理的方法例如：焚烧、氯氧化、臭氧氧化和燃烧，生物的处理方法例如：生物修复、传统堆肥法等等。现在，随着技术的发展，含油污泥的低温冷处理和生物修复成为了两条有效的处理途径。
低温冷处理技术作为一种物理的处理方法能有效地增加污泥的脱水性质，改变絮凝剂的结构形式并减少污泥周围的水含量。比较那种“初沉降”，冷处理能够除掉溶液中的杂质，因此达到更好浓缩目的，最

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The ways of regular sludge and oily sludge treating
Generally speaking， there is a procedure for treating sludge after secondary treatment of wastewater if we want to prevent our living environment from second polluting. Wastewater treatment objectives are accomplished by concentrating impurities into solid form and then separating these solids from the bulk liquid. This concentration of solids， referred to as sludge， contains many objectionable materials and must be disposed of properly. Sludge disposal facilities usually represent 40 to 60 percent of disposed of the construction cost wastewater-treatment plants， account for as much as 50 percent of the operating cost， and are the cause of a disproportionate share of operating difficulties.
First of all， the initial sludge is separated from the clean water lying upon it in the secondary clarifier by pumping it to a tank. Because the initial sludge have a high water content that usually can up to 99.5 percent in volume， sludge thickening is a necessary procedure， and there are several techniques are available foe volume reduction. Mechanical methods such as vacuum filtration and centrifugation may be used where the sludge is subsequently to be handled in a semisolid state. There methods are commonly used preceding sludge incineration. Where further biological treatment is intend，volume reduction by gravity thickening or flotation is common practice. In both cases， the sludge remains in a liquid state.
Gravity thickeners are very similar in design and operation to the secondary clarifiers used in wastewater treating systems. The thickening function is the major design parameter， and tanks are generally deeper than secondary clarifiers to provide greater thickening capacity. A well-designed， well-operated gravity thickener should be able to， at least double the solids content of the sludge. In another word， the water content ratio of sludge can be reduced from 99.5 percent in volume to 98 percent or ever much more reduction. It should be noted that the design of gravity thickeners should be based on the results of pilot plant analysis wherever possible， since successful loading rates are highly dependent on the nature of the sludge.
In dissolved air flotation， a small quantity of water， usually secondary effluent is subjected to aeration under a pressure of about 400kPa. This supersaturated liquid is then release near the bottom of a tank through which the sludge is passed at atmospheric pressure. The air is release in the form of very small bubbles that attach them selves to， or become entrapped in， the sludge solids， floating the solids to the surface. The thickened sludge is skimmed off at the top of the tank while the liquid is removed near the bottom and is returned to the aerator.
After volume reducing， sludge represents a considerable hazard to the environment and must be rendered inert prior to disposal. The most common means of stabilizing is by biological degradation. Because this process is intended to convert solids to unicellular end products， the term digestion is commonly applied to this process. Sludge digestion serves both to reduce the volume of the thickened sludge still further and to render the remaining solids inert and relatively pathogen-free. These goals can be accomplished by either anaerobic or aerobic digestion.
Sludge contains a wide variety of organisms， and thus requires a wide variety of organisms for its decomposition. The literature relating to anaerobic sludge digestion often divides the organisms into two kinds， the acid formers and the methane formers. So we can divide the anaerobic sludge digestion into two steps too. On the first step， the acid formers consist of facultative and anaerobic bacteria that solubilize the organic solids through hydrolysis. The soluble products are then fermented to acids and alcohols of low molecular weight. The second step， the methane formers consist of strict anaerobic bacteria that convert the acids and alcohols， along with hydrogen and carbon dioxides to methane. Becau

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楼主的资料是中英文对照的，不错，可以提高一下英文水平。值得好好读一下。

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