Biowäscher und Biofilter. Prinzipien der biologischen Abluftreinigung (German Edition)
Book file PDF easily for everyone and every device.
You can download and read online Biowäscher und Biofilter. Prinzipien der biologischen Abluftreinigung (German Edition) file PDF Book only if you are registered here.
And also you can download or read online all Book PDF file that related with Biowäscher und Biofilter. Prinzipien der biologischen Abluftreinigung (German Edition) book.
Happy reading Biowäscher und Biofilter. Prinzipien der biologischen Abluftreinigung (German Edition) Bookeveryone.
Download file Free Book PDF Biowäscher und Biofilter. Prinzipien der biologischen Abluftreinigung (German Edition) at Complete PDF Library.
This Book have some digital formats such us :paperbook, ebook, kindle, epub, fb2 and another formats.
Here is The CompletePDF Book Library.
It's free to register here to get Book file PDF Biowäscher und Biofilter. Prinzipien der biologischen Abluftreinigung (German Edition) Pocket Guide.
Although, the basic pollutant removal mechanisms of all the reactors are more or less similar, differences exist in the use of microorganisms may be either in suspended in liquid or immobilized biofilm form , packing media, pollutant concentration etc. Although all biological gas treatment technologies involve biodegradation of contaminants by a microbial population, several different process configurations may be employed. These include. Bioscrubbers are reactors in which the gaseous pollutants are first absorbed in a free liquid phase prior to biodegradation by either suspended or immobilized microorganisms.
The microbial process occurs either in the absorber or in a separate bioreactor after absorption of the pollutants. A bioscrubber unit shown in Fig. In the absorption unit, input gaseous contaminants are transferred to the liquid phase.
Gas and liquid phases flow counter currently within the column, which may contain the packing material. Nevertheless, the addition of inert packing provides increased transfer surface between the VOC and the aqueous phase The washed gaseous phase is released at the top of the column whereas the separated contaminated liquid phase is pumped to an agitated, aerated bioreactor. This reactor unit contains the appropriate microbial strains suspended in the aqueous phase in nutrient solution media essential for their growth and maintenance. Most of the bioscrubbers being operated presently use activated sludge derived from wastewater treatment plants as inoculums In some cases, bioreactors are directly inoculated with specific degrading strains.
The residence time for such bioreactors range between 20 and 40 days and these are operated practically as activated sludge processes including recycle of sludge. Part of the treated solution is recycled for absorption of VOCs to the absorption unit. Substantial modifications in bioscrubber design have been done in the recent past to enhance their performance for VOC and odour treatment.
- Customer Reviews!
- Drake [The Texas Senators Sons 3] (Siren Publishing Classic).
- musik anlage | eBay.
Some modified bioscrubber units are Sorptive-slurry bioscrubber, Anoxic bioscrubber, Two-liquid phase bioscrubber, Airlift bioscrubber, Spray column bioscrubber. Biological trickling filters combine pollutant absorption and biodegradation in the same reactor. Pollutant degrading bacteria are naturally immobilized on a packing material which is either a random packing e. The schematic description of a typical biotrickling filter BTF is provided in Fig. In such a filter, the gas is carried through a packed bed, which is continuously irrigated with an aqueous solution containing essential nutrients required by the biological system.
Several studies have shown that the choice of a co- or counter-current configuration for liquid and gaseous phases does not influence the biodegradation performance Microorganisms grow on the packing material of the biofilter as biofilm. The pollutant to be treated is initially absorbed by the aqueous film that surrounds the biofilm, and then the biodegradation takes place within the biofilm.
The filtering material used in a BTF has to facilitate the gas and liquid flows through the bed, favor the development of the microflora, and should resist crushing and compaction. BTF packing that best meet these specifications are made from inert materials such as resins, ceramics, celite, polyurethane, foam 11 etc.
As they are made from inert or synthetic material, BTFs need to be inoculated with suitable microbial culture. The use of activated sludge as initial microbial inoculum has been extensively reported 33 Biofilter BF processes differ from scrubbing techniques in that no free liquid phase is involved. As far as waste air treatment is concerned, biofilters have proven cost effective operation mainly in two fields: odour abatement and organic solvent vapours removal from waste air steams.
Biowascher Und Biofilter. Prinzipien Der Biologischen Abluftreinigung
In this process, contaminated gas is passed through a reactor containing an active microbial biofilm attached to a solid packing medium. Contaminants are transferred from the gas phase to the biofilm where they are oxidized to carbon dioxide, water, and biomass. Contaminant transfer from the gas phase directly into the biofilm minimizes the mass transfer from the gas phase to a large moving aqueous phase and then to the biofilm The basic components of a biofilter include a packed bed reactor, a system for maintaining moisture content, and a blower to push or pull contaminated air through the porous medium.
Several process configurations may be used. For example, air flow may be either up-flow or down-flow and water may be added to maintain moisture content by humidifying influent air or to the filter bed via a sprinkler or soaker hose.
Packing media may consist of natural materials e. BFs now find wide application in treatment of several VOCs and odours.
Book Judaism An Introduction Ibtauris Introductions To Religion 2010
Among these are odourants such as ammonia, hydrogen sulphide, mercaptan,disulphides, etc. Bench and pilot scale studies have shown that 60 out of hazardous air pollutants HAPs can be successfully treated with biofiltration 20 BFs are typically used for the treatment of large volumes of air streams containing low concentration of VOCs or odorants. The advantages and disadvantages of BFs are discussed below. These reactors require large areas, and are also exposed to climate changes.
These reactors require less space than the open configuration. Passage of stringent air pollution laws and regulations has increased the need for cost an emerging technology for control of VOCs emissions from a variety of contaminated air streams 35 Biofiltration is well suited for treatment of waste gas streams characterized by high flow rates with low concentrations of biodegradable pollutants. In recent years, biological treatment has expanded to applications in control of volatile organic compounds VOC in gas streams originating from a variety of industrial facilities and environmental remediation activities.
Various non- biological methods exist for treatment of air contaminated by low concentrations of VOCs, and these are usually described as secondary treatment technologies. Economic and regulatory constraints usually dictate the choice of technology used, and process selection is normally based on the nature, flow, and mode of emission. While several methods of contaminant removal are technically feasible for dilute VOC concentrations, most of the currently used methods have disadvantages.
For example, thermal incineration is one of the most widely used secondary treatment technologies While the process is capable of high removal efficiencies, supplemental fuel is required, thus adding to the process cost, and secondary pollutants are generated e. Adsorption using activated carbon allows for high VOC removal efficiencies particularly when low pollutant concentrations are involved. However, pollutants are transferred to the adsorbent rather than being destroyed, and the adsorbent must be regenerated or disposed of.
Adsorbent regeneration or disposal can lead to high investment costs, while at the same time producing secondary pollutants. Biological treatment of VOC contaminated gases may meet treatment goals for many waste gas streams while at the same time minimize the disadvantages encountered with other treatment technologies.
Science & Mathematics | Strand Books
The most important physical, chemical and biological parameters influencing the biofiltration process are described below. The first step in the biofiltration process is the transfer of contaminants from the air to the water phase. This is generally not a rate-limiting step, and so one frequently assumes that the gas and liquid are at equilibrium. The biofilm is a key element of the BF, which brings about the biodegradation of the pollutants viz. VOC and odorous compounds. The thickness of the biofilm is influenced by several factors. These include the type of pollutant, its rate of flow through the BF, the bedding material used, and the design and configuration of the treatment system being used.
Biofilm thickness usually varies from tens of micrometers to more than 1 cm, although an average of 1 mm or less is usually observed Above this level, the diffusion of nutrients becomes a limiting factor Various steady state and dynamic mathematical models have been reported in literature to predict the substrate, oxygen and nutrient penetration profile in the biofilm and facilitate evaluation of overall biofilm effectiveness factor 38 43 The BF bed constitutes the heart of the biofiltration process because it provides the support for microbial growth.
Bohn established a list of characteristics that an ideal BF bed should possess. The most important desirable characteristics of the BF bed include a high specific surface area for development of a microbial biofilm and gas-biofilm mass transfer, b high porosity to facilitate homogeneous distribution of gases, c a good water retention capacity to avoid bed drying, d presence and availability of intrinsic nutrients, and e presence of a dense and diverse indigenous microflora.
Peat, soil, compost, and wood chips, are the most frequently employed basic materials in BF beds. These materials satisfy most of the required desirable criteria, and are widely available at low cost. Each of these materials has their own merits and demerits. The main advantage of soil is that, it offers a rich and varied microflora. It however, contains only a few intrinsic nutrients, presents low specific surface area and generates high-pressure drops Peat has high amounts of organic matter, high specific surface area, and good water holding capacity and good permeability.
However, peat contains neither high levels of mineral nutrients nor a dense indigenous microflora as in the case of soil or compost.
- Hard Hearted Hannah (The Vamp of Savannah).
- Narrow Results By.
- Items in search results.
- Protein Aggregation and Fibrillogenesis in Cerebral and Systemic Amyloid Disease: 65 (Subcellular Biochemistry).
- About This Item.
- Tips for Tourists in Mexico.
Composts are materials that are most frequently employed in biofiltration for a variety of reasons. Compost offers a dense and varied microbial system, good water holding capacity, good air permeability, and contains large amounts of intrinsic nutrients. Moreover, the utilization of compost in BFs constitutes an effective way of recycling and utilizing waste residual organic matter, such as activated sludge from wastewater treatment plants, forest products branches, leaves, barks , domestic residues, etc 6.
However, composts are often less stable than soil or peat and have the tendency to break down and become compact, leading to increase in pressure drop in BF beds. This among other reasons is attributed to their high water holding capacity. TEA causes environmental pollution problems and adverse effects on ecology. In addition, it can endanger human health. Animal experiments have revealed that TEA could cause irritation to the dermal, ocular and respiratory systems, such as asthma and visual disturbances and long-term exposure to TEA could result in abnormal embryos.
TEA has been considered to be a possible carcinogen. Therefore, it is necessary to remove TEA from water and gas in the environment. Biological waste air treatment techniques utilize the capacity of microorganisms, mainly bacteria, to aerobically oxidize chemicals. Gaseous pollutants or vapours are sorbed into an aqueous phase prior to biodegradation. The end products of the biodegradation of C, H, O containing pollutants is in most cases, carbon dioxide, water and biomass.