A diagnosis expert system for the activated sludge process was developed in conformity to our experience and reported studies. This straightforward guide includes figures, tables, worksheets, photomicrographs, and blackandwhite drawings of many living, microscopic components of the activated sludge process. Describe the rising sludge problems in an activated sludge plant. Variation in dissolved oxygen concentration and its effect on. The process involves the activation of a mass of microorganisms which have the ability to stabilize organic matter in wastewater metcalf and eddy, 2003. Two hundred images for each sample were captured by a systematic examination of the slides. A practical, handson guide to using the microscope to analyze activated sludge in wastewater treatment. The minor organisms are the metazoa or multicellular, microscopic animals and macroscopic invertebrates figure 1. Compare the microscopic results with laboratory process data in an activated sludge plant. The activated sludge process is efficient and economical. The microscope provides the wastewater treatment plant operator with a special tool for process control and troubleshooting of the activated sludge process. Four common variations of the activated sludge process are.
Discuss the interpretation of microscopic study of the mlss. Total solids can be classified as either suspended solids or filterable solids by passing a known volume of liquid through a filter. The activated sludge is then separated from the liquid by clarification. Microscopic examination of the activated sludge during chlorination is recommended to. The purpose of which is to collect the biological sludge which often settles quite rapidly due to their oxidised nature. Activated sludge process plants are good choices too for isolated facilities, such as hospitals or hotels, cluster situations, subdivisions, and small communities. Most modern wastewater treatment plants are subject to increasingly strict effluent discharge limits and must continuously be updated and optimized to meet the requirements. Process control tests for domestic wastewater treatment. A new method for segmentation of microscopic images on. Microscopic investigation of filamentous microorganisms in. Microscopic examination of the activated sludge process wiley.
The paper they published in 1914, first used the term activated sludge. Microscopy, including microscopic measurements and techniques. The operation of wastewater treatment plants that use activated sludge should be based on comprehensive control of the processes involved. However, in activated sludge systems there is the possibility that lighter. Pdf suitability of sludge biotic index sbi, sludge index. The activated sludge process is aerated to degrade organic material and to achieve nitrification. The course curricula for the activated sludge precertification training. Process control of activated sludge plants by microscopic. Lockett, added the concept of recycling sludge and patented the process. Evaluation of the accuracy of two simple methods for.
Microscopic examination effluent grab x computation of svi, fm ratio, sludge age, andor mcrt, as desired effluent as data collected secondary clarifier sludge blanket depth as appropriate in situ x final effluent parameters, sample types, and frequencies as required by permits. Jul 30, 2019 activated sludge and aerobic biofilm reactors. Pa wastewater module 16 the activated sludge process part ii. The deleterious effects of sludge bulking and foaming occur mainly in the clarification tank, and result in degradation of effluent quality. Activated sludge is an enrichment culture of micro and macro organisms that remove or change components considered to be pollutants. The settled sludge is either returned ras or wasted was. Photmicrographs are from a number of sources, courtesy of iowa rural water, tamdat co. Davyhulme sewage works, manchester, uk, first full. Written for plant operators and technicians and avoiding unnecessary technical jargon, microscopic examination of. Activated sludge is commonly used as a wastewater treatment.
However, if methods regarding sludge investigation are to be helpful to plant operators, the method must be quick, simple and cheap and should provide additional information that is complementary to the results of chemical analyses. Mar 02, 2016 activated sludge process most commonly used secondary treatment process microbes, mainly aerobic heterotrophic bacteria, are involved designed to remove soluble biodegradable organic matter removal of nutrients, tss, pathogens and heavy metals is coincidental usually clarified sewage primary effluents is treated primary. The following is an overview of the component steps of the activated sludge process in which these two problems occur. Segmentation of microscopic images is a challenging process due to lack of focus.
Actinomycetes predominate microscopic examination, dissolved iron content. The activated sludge process is widely used by large cities and communities where large volumes of wastewater must be highly treated economically. A practical, handson guide to using the microscope to analyze activated sludge in wastewater treatment the microscope provides the wastewater treatment plant operator with a special tool for process control and troubleshooting of the activated sludge process. In the first instance the material refers to wastewater treatment. A fundamental aspect of this control ought to be microscopic tests of activated sludge. Microscopic examination of activated sludge educational objectives upon completion of this course, the operator should be able to use the microscope to view microorganisms present in activated sludge, understand their differences, metabolism and correct distribution to achieve optimum wastewater treatment. The activated sludge process is widely used for treating wastewater.
Activated sludge aggregates filaments morphology chemometric techniques abstract in wastewater treatment processes, and particularly in activated sludge systems, ef. The sbr has the advantage of reducing space, material and chemical use compared to the traditional activated sludge treatment process. This activated sludge training manual was prepared by the michigan department of environmental quality, operator training staff. Evaluate the process based on sludge quality microscopic, svi, observations. Activated sludge process most commonly used secondary treatment process microbes, mainly aerobic heterotrophic bacteria, are involved designed to remove soluble biodegradable organic matter removal of nutrients, tss, pathogens and heavy metals is coincidental usually clarified sewage primary effluents is treated primary. Microscopic examination of activated sludge educational objectives upon completion of this course, the operator should be able to use the microscope to view microorganisms present in activated sludge, understand their differences, metabolism and correct distribution to. Thus, microscopic sludge investigation is an important part of controlling the activated sludge process. The principle role microorganisms have in the activated sludge process is to convert dissolved and particulate organic matter, measured as biochemical oxygen demand bod, into cell mass. Evaluate the need to increase or decrease the waste activated sludge rate. The operator can read the organisms and use them as bioindicators to determine if operational conditions are acceptable or not. Activated sludge process control, part 3 this two 2 day workshop provides the knowledge and skills required to evaluate and control the operation of an activated sludge treatment plant using microscopic examination. This is very generous on the part of iwa to make these excellent references available to everyone at no charge. Operational problems such as bulking and scum formation occur when the wrong microorganisms are dominating the sludge population. Typically microscopic examination is used to identify problems with floc.
The activated sludge process in1914, british researchers edward ardern and w. The activated sludge microbiology problems and their control pdf. A practical, handson guide to using the microscope to analyze activated sludge in wastewater treatment the microscope provides the wastewater treatment. The major organisms by numbers and roles performed in the activated sludge process are the bacteria and protozoa figure 1. Microscopic examination of the activated sludge process by. Notes on activated sludge process control page ii total solids are defined as all the matter that remains as residue upon evaporation at 103 to 105 oc.
Filamentous growth microscopic examination, do, ph, nitrogen concentration. The objective of this talk is to make you aware of some of the typical microbial. Process stability and final effluent quality largely depend upon the composition of the biomass in an activated sludge plant. These methods are easy, fast and inexpensive compared to other approaches, and are generally understandable and accepted. The program will focus on the basic and more advanced microscope techniques, including observation of protozoa and. Activated sludge monitoring through microscopic examination the basis of as systems is the growth of flocforming bacteria upon a filamentous bacteria backbone which settle under gravity in the final clarifier, leaving a clarified supernatant and a thickened return sludge. It equips plant operators and technicians to monitor, regulate, and troubleshoot the treatment processes and also serves as a valuable resource for research. The activated sludge excess biomass or cell mass removed from the secondary treatment process. Microscopic examination of the activated sludge process. Describe the various modes of the activated sludge process. Therefore, adjustment of the focus is required for every movement of the mobile stage. Describe troubleshooting methods for the activated sludge process. Protozoa remove and digest freeswimming bacteria protozoa remove other suspended particles present in the activated sludge this process improves the clarity of the effluent.
I have been in the wastewater profession since 1962 and trained activated sludge process control since 1974, this is the best course in which i have trained. Influent to activated sludge aeration tank from primary settling tank and return activated. Assessment of the oxygen uptake rate and microscopic examination of the activated sludge will help determine what is causing bulking and foaming. The activated sludge process contains a large number and a large diversity of organisms. Sometimes, a visual check of the mixed liquor can reveal operational problems. Activated sludge characterization through microscopy. Microscopic examination of the activated sludge process by michael h. The basic asp, according to riftat 20 consists of three components. The microscopic analysis of sludge samples proved that after pax addition, flocs appeared more compact and dense mamais et al. Microscopic examination of the activated sludge process is a great tool for process control and troubleshooting. Davyhulme sewage works, manchester, uk, first fullscale activated sludge plant. A new method for segmentation of microscopic images on activated sludge article pdf available in turkish journal of electrical engineering and computer sciences 23. Pdf a new method for segmentation of microscopic images. The operator can read the organisms and use them as bioindicators to determine if operational conditions are acceptable or not acceptable.
The books listed above from iwa publishing are free to download as pdf files below. For activated sludge, we recommend a daily examination. Activatedsludge process the activatedsludge process is an aerobic, continuousflow system containing a mass of activated microorganisms that are capable of stabilizing organic matter. The process used for this work consist of a sequential batch reactor sbr, where municipal sewage is treated biologically with an active sludge process.
Requirements good binocular phase contrast microscope with 10x and 100x. Filamentous foaming and bulking in activated sludge. For an aerated stabilization basin, the key is to develop a good baseline of examinations over time by analyzing a few times per week. The operator can read the organisms and use them as bioindicators to determine if. You can examine a sludge sample to determine the organisms it contains, and use the organisms as bioindicators that let you know if your operating conditions are optimal. Activated sludge treatment process concept and system.
In the activated sludge treatment process, the removal of suspended solids from wastewater is usually through gravity separation in a clarifier. Comparison of the results from microscopic tests concerning. Activated sludge microbiology problems and their control. The process consists of delivering clarified wastewater, after primary settling, into an aeration basin. Bpgcs002 wastewater treatment activated sludge process the following is intended to provide a first check for those involved in the operation, management and monitoring of the activated sludge process to confirm that good practices are in place. Activated sludge is a process in sewage treatment in which air or oxygen is forced into sewage liquor to develop a biological floc which reduces the organic content of the sewage. It is intended to be used as an aid in the presentation of the mdeq activated sludge process control training course, along with numerous handouts, class discussion, and an abundance of slides. Then you can perform additional examinations during upset conditions. Activated sludge samples were taken from the konya wastewater treatment plant. In a conventional activated sludge process, microorganisms use oxygen to break down waste so it can be used as food for their growth and survival. Floc morphology was judged by light microscopy olympus n547 examination according to a classification scheme. Conventional activated sludge extended aeration completely mixed activated sludge the contact stabilization process. For most treatment plants, this will be a portion of the return activated sludge ras flow stream.
Not make you an expert in activated sludge microscopy. This training manual presents material on the use of a compound microscope to analyze microscope communities, present in wastewater treatment processes, for operational control. Wastewater treatment plant operator toolbox nys dept. Its value lies in the students extensive testing and the interpretation. Using the biota observed by microscopic and data measurement easily obtained, i. Typically microscopic examination is used to identify problems with floc formation, settling, bulking and solids separation problems. Microscopic examination activated sludge process brittany. Its value lies in the students extensive testing and the interpretation involved.
The activated sludge microbiology problems and their control pdf document has detailed guidance on problems and control. Standardize your microscopic examination procedures as much as possible. Microscopic investigation of activated sludge 23 3. Variation in dissolved oxygen concentration and its effect. This lecture will not make you an expert in activated sludge microscopy. Pdf comparison of the results from microscopic tests. Microscopic examination of activated sludge david jenkins university of california, berkeley operations and control of activated sludge processes using microbiological analysis ljubljana, slovenia june 57, 2019. Fundamentals of wastewater treatment and engineering. Activated sludge is a biological process that utilizes microorganisms to convert organic and certain inorganic matter from wastewater into cell mass. Sludge return rate too high return sludge concentration, solids level around final clarifier and settleability test. Chlorination must be used only when the target value of svi is regularly exceeded. Diagnosis expert system for the activated sludge process.
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