Aeration Tank Volume Research Articles

Microbial Formation on Different Biomedia Surface for Wastewater Treatment

Even though commercial plastic media such as Cosmoball successfully treated municipal wastewater without clogging, its inadequate surface area prevents its use for high biofilm growth rates. This study compares microbial formation on the activated carbon (AC)-coated and non-coated Cosmoball media by submerging four activated carbon AC-coated Cosmo balls and non-coated Cosmo balls in five-liter beakers containing municipal wastewater. The researchers then analyzed the surface morphology of the biofilms on the coated and non-coated surfaces and applied the next-generation sequencing (NGS) technology to the ecology of microbial-mediated processes. By Day 11, the AC-coated media showed a biofilm coverage of 95%, whereas the non-coated media had a biofilm coverage of about 70%. The research has demonstrated that the coated media has a four times higher surface area, thus saving as much as 50% of the aeration tank volume.

PERENCANAAN INSTALASI PENGOLAHAN AIR LIMBAH DOMESTIK SYSTEM LUMPUR AKTIF DI GEDUNG TRANS MART

This study aims to design a waste water treatment plant (WWTP) design; reference in making WWTP in another place; and do waste water treatment so it is not harmful to the surrounding environment. The location of the research in the Jakarta Transmart building, when this research was conducted in March to June 2018. The method used in the implementation of this study planning was the preparation of reports that included analysis of waste characteristics; review of literature studies that are used to study supporting theories during conducting problem analysis and discussion so that they can be considered into the planning of wastewater treatment institu- tions that will be carried out; collection of primary data and secondary data as material for study of wastewater treatment plant planning; and design, calculation of the dimensions of the wastewater treatment plant, technical specifications. Planning criteria, among others: processing efficiency and achieving target results in accordance with desired quality standards; land area needed; and care must be easy and simple. The results showed that the estimated discharge of water requirements found in the Transmart building was around 59.97 m³ / day, obtained from the calculation of the area of the building building to meet the needs of clean water needed per square meter. Aeration tank volume and Aeration 1 dimensions: 3.35 m long, 4.450 m wide, 2.550 m depth, 0.625 m free space height, 38.01 m³ volume. Aeration 2: 3.375 m long, 4.450 m wide, 2.550 m depth, 0.625 m free space height, 38.3 m³ volume. Total aeration body area = 76,315 m. Tub sedimentation: 3.35 m long, 2.850 m wide, 2.350 m depth, 0.90 m free space height, 38.3 m³ volume. Volume: 13.7. Tub Equalization: 2.625 m long, 5.975 m wide, 2.60 m depth, free space height 0.575 m, volume 40 m³. In the design of planning the installation of wastewater treatment systems for activated sludge should be added or further processing so that the water from processing can be reused and not wasted, such as filtration so that it can be used such as for washing vehicles, watering plants etc.

PEMANFAATAN LIMBAH KULIT SINGKONG (Manihot Utilissima) DALAM MEMPENGARUHI KADAR FE DALAM AIR

This study aims to design a waste water treatment plant (WWTP) design; reference in making WWTP in another place; and do waste water treatment so it is not harmful to the surrounding environment. The location of the research in the Jakarta Transmart building, when this research was conducted in March to June 2018. The method used in the implementation of this study planning was the preparation of reports that included analysis of waste characteristics; review of literature studies that are used to study supporting theories during conducting problem analysis and discussion so that they can be considered into the planning of wastewater treatment institu- tions that will be carried out; collection of primary data and secondary data as material for study of wastewater treatment plant planning; and design, calculation of the dimensions of the wastewater treatment plant, technical specifications. Planning criteria, among others: processing efficiency and achieving target results in accordance with desired quality standards; land area needed; and care must be easy and simple. The results showed that the estimated discharge of water requirements found in the Transmart building was around 59.97 m³ / day, obtained from the calculation of the area of the building building to meet the needs of clean water needed per square meter. Aeration tank volume and Aeration 1 dimensions: 3.35 m long, 4.450 m wide, 2.550 m depth, 0.625 m free space height, 38.01 m³ volume. Aeration 2: 3.375 m long, 4.450 m wide, 2.550 m depth, 0.625 m free space height, 38.3 m³ volume. Total aeration body area = 76,315 m. Tub sedimentation: 3.35 m long, 2.850 m wide, 2.350 m depth, 0.90 m free space height, 38.3 m³ volume. Volume: 13.7. Tub Equalization: 2.625 m long, 5.975 m wide, 2.60 m depth, free space height 0.575 m, volume 40 m³. In the design of planning the installation of wastewater treatment systems for activated sludge should be added or further processing so that the water from processing can be reused and not wasted, such as filtration so that it can be used such as for washing vehicles, watering plants etc.

SISO P-ILC Algorithm for Output Data Dropouts and Its Application in Wastewater Biological Treatment Plant

In order to improve the efficiency of sewage treatment, We construct P-ILC algorithm for output data dropouts.The P-ILC algorithm is used in the aeration tank of oxygen input link, and according to the actual situation, considering the data generating omissions, adjusting the algorithm can completely control the aeration tank of oxygen. After 15 iterations, we can completely control the oxygen in the aeration tank volume. We know more important is this algorithm may at any time according to need of aeration tank of oxygen supplement, when the lack of oxygen, can open the oxygen filling pump, when sufficient oxygen, close the oxygen filling pump, to achieve energy saving goals, ultimately makes the economic benefits to achieve the highest.

An experimental study on manganese(II) removal with manganese dioxide recycling

Manganese dioxide (MnO2) particles have a catalytic effect on removing Mn(II) from contaminated water. On the basis of this effect, a manganese removal process was proposed in this paper. For this purpose, the oxidation of Mn(II) was studied first in batch reactor and then in continuous reactor. The experimental conditionals for batch reactor were Mn(II): 3 mg/l, Mn(IV): 0–800 mg/l, pH: 9.6, temperature: 25°C and for continuous system, the conditionals were kept the same except Mn(II) concentration. A quadratic equation was obtained as a function of Mn(IV) concentration to determine the catalytic reaction rate constant. It was experimentally demonstrated that there was no significant effect of Mn(IV) on the Mn(II) oxidation at Mn(IV) concentrations beyond 800 mg/l. Furthermore, reaction kinetics was derived from the data of batch experiments. Based upon the reaction kinetics, it has been theoretically demonstrated that the volume of aeration tank can be significantly reduced by keeping a high concentration of Mn(IV) in the reactor. Lastly, manganese oxidation was studied in a continuous flow lab scale system with and without MnO2 sludge recirculation. In this system, until Mn(IV) concentration had reached 300 mg/l, Mn(II) removal rate had increased linearly, but beyond this level increase had continued decreasingly. This study shows that, instead of using stronger oxidants in the drinking water treatment systems, recycling of MnO2 flocks provides important advantages like low investment cost, minimization of treatment area and, because of the lack of using oxidants, low operation cost.

Bioaugmentation to Improve Nitrification in Activated Sludge Treatment

Bioaugmentation is a proposed technique to improve nutrient removal in municipal wastewater treatment. Compared with commonly used nitrification/denitrification (NDN) processes, bioaugmentation may be able to reduce tankage or land requirements. Many approaches for bioaugmentation have been developed, but few studies have compared the benefits among different approaches. This paper quantifies the effectiveness of bioaugmentation processes and investigates three major "onsite" bioaugmentation alternatives: 1) the parallel-plants approach, which uses acclimated biomass grown in a nitrifying "long-SRT" (sludge retention time) plant to augment a low-SRT treatment plant; 2) the enricher-reactor approach, which uses an offline reactor to produce the augmentation cultures; and 3) the enricher-reactor/return activated sludge (ER-RAS) approach, which grows enrichment culture in a reaeration reactor that receives a portion of the recycle activated sludge. Kinetic models were developed to simulate each approach, and the benefits of various approaches are presented on the same basis with controllable parameters, such as bioaugmentation levels, aeration tank volume, and temperatures. Examples were given to illustrate the potential benefits of bioaugmentation by upgrading a "carbon-only" wastewater treatment plant to nitrification. Simulation results suggested that all bioaugmentation approaches can decrease the minimum SRT for nitrification. The parallel-plants approach creates the highest concentration of biomass but may fail at too low temperature. The ER-RAS approach likely would be more useful at lower temperature and required less reactor volume; enricher-reactor approach would likely be more advantageous in the presence of inhibitory compound(s).

A simulation-based optimisation approach to control nitrogen discharge by activated sludge under winter seasonal peak load

Wastewater treatment systems located in cold areas are under increasing pressure to remove nitrogen from their wastewater. As constraining operating conditions like dramatic influent load increases exacerbated by cold temperatures can occur (e.g. winter tourist resorts, ski resorts), specific technical treatment solutions have to be adapted. The objective of this research is to determine the maximal magnitude of load variation which can be applied in winter to an activated sludge treatment system. It aims at analyzing the effects of high influent load variations on the nitrogen removal capacity. Two operating strategies are investigated by dynamic simulations performed with ASM1: • A fixed aeration tank volume with a fixed MLTSS concentration • A variable aeration volume tank with a variable MLTSS concentration It is demonstrated that the variable aeration tank volume strategy is more efficient than the fixed volume strategy to face long-term peak load. To meet an effluent ammonia nitrate concentration of below 10 mgN·l-1, a maximum input load increase by a factor 2 should be applied with the first strategy; whereas with the second strategy a load increase by a factor 4 should be applied (with constant oxygen presence time). If the oxygen presence time can be increased by 50% the maximum input load increase could reach a factor 6. Water SA Vol.32 (4) 2006: pp.561-566

Upgrading of Existing Municipal Wastewater Treatment Plants with the “Non-Conventional Low MLSS MBR Technology”

In the future, upgrading of existing wastewater treatment plants (wwtps) will be more important than the erection of entirely new plants, as most of the plants necessary in Germany already exist. Thus far, membrane bioreactor (MBR) technology is not used as an alternative for plant upgrading in Germany. However, at several locations the preconditions indicate that the application of the MBR technology for upgrading of plants may be favorable. These preconditions include the need for a substantial enlargement of the aeration tank volume and/or the need to improve the efficiency of the final sedimentation tanks, and also require that the existing tanks be in a good state, so that the tanks can be used in the future. The relevant preconditions and the basic upgrading concept using the MBR technology were presented earlier. Depending on the local preconditions regarding the existing tank volume, a specific aspect of this application can be an operation mode using non-conventional low MLSS (mixed liquor suspended solids) concentrations (5 kg MLSS/m 3 through 7 kg MLSS/m 3 ) due to the amount of the existing tank volume. Two research projects were carried out covering the operation of five pilot plants on a cubic meter scale to demonstrate the feasibility of this kind of MBR process. This paper presents the core results of this research work.

A new side stream process for easily degradable industrial waste waters to avoid sludge bulking

A new treatment scheme for the treatment of easily biodegradable industrial waste waters has been developed. The side stream treatment of dairy waste water with the excess sludge from the domestic treatment line of the regional treatment plant Bad Vöslau has been operated successfully for a period of three years during which the industrial load stemming from the dairy increased from 800 kg COD/d to 2,500 kg COD/d with peak loads up to 5,000 kg/d. Despite of the increased load to the treatment plant the total aeration tank volume had not been increased. This treatment is performed in an existing aeration tank of the WWTP (V = 1,800 m3) which is now used as contact tank for the combined aeration of dairy waste water and excess sludge from the domestic treatment line (volume aeration tank = 15,000 m3). In this tank the easily degradable substrate from the industrial waste is mainly adsorbed to the biological sludge and after a mechanical dewatering transferred to the anaerobic digester where it yields in an increased gas production. The filtrate of the dewatering process is completely free from biodegradable material and can without danger of bulking be fed to the aeration tank of the domestic treatment line. The new process has proven to be extremely flexible since already now daily peak loads exceeding the design load by more then 60% could be treated in the plant without any problems. Compared to other alternatives for the dairy waste water treatment that were investigated during this study, the new side stream process is very advantageous. No other pre-treatment process for industrial waste water could have been operated under comparable loading conditions without severe operating problems.

An innovative approach to maximize primary treatment performance

This paper describes the development of a cost-effective modified primary treatment method which can significantly increase the removal of both soluble and colloidal COD without resorting to the use of any chemical coagulant. It involves recycling a small portion of the primary sludge and then activating it to enhance its biosorptive and flocculent properties through 30-min aeration. The aerated sludge is then brought into contact with raw sewage to induce rapid biosorption of soluble COD and flocculation of colloidal organic before the mixture is settled in a regular primary clarifier. In this treatment approach, the raw sewage is not subjected to aeration; thus the sludge aeration tank volume and the aeration energy requirements can be minimized. In fact, with 30-min sludge aeration, theyamount to only 1.25% and 8.5%, respectively, of those required in the conventional activated sludge system. Through this modified approach with a 15% sludge recycle rate and 30-min sludge aeration, the COD removal efficiency is 43.9% higher than that of the regular primary treatment. This would result in a significant improvement of the primary effluent quality, or achieve a substantial reduction of organic loading to the secondary biological system.

Minimizing costs of activated‐sludge systems

The concentration of mixed liquor suspended solids (MLSS) in aeration tanks affects the required aeration tank volume and the surface area required for secondary settling. As the MLSS increases, the required aeration volume decreases, resulting in decreased construction costs; however, because of solids‐flux limitations, the required clarifier surface area increases with an increase in MLSS, and the cost for clarifiers increases. The total cost of an activated‐sludge system is a minimum at an intermediate MLSS concentration. Previous investigators have shown that the MLSS at which total system cost is minimum depends on sludge settling properties. The optimum MLSS is higher for sludge that settles well than for sludge that settles poorly. This paper demonstrates for the first time that the mass of biological solids that needs to be maintained in the aeration tanks affects the optimum MLSS. Plants with a high mass of biological solids—such as with nitrification or biological nutrient removal—should be designed for higher MLSS than plants with low biological solids. Similarly, plants without primary settling should be designed for higher MLSS than plants with primary settling. The MLSS value at the minimum system cost can be determined using curves for costs of aeration tanks and secondary settling. For plants with multiple units (for example, the Deer Island Treatment Plant in Boston, Mass.), where the cost of each additional aeration tank or secondary clarifier is relatively constant, the impact of additional secondary clarifiers can be assessed in combination with the need for fewer aeration tanks. The ideal MLSS is specific to a particular combination of flows, waste strengths, and cost setting, but the optimum MLSS can be readily determined for particular cases.

Adaption of the main waste water treatment plant in Vienna to meet Austrian emission regulations

The modification of the main waste water treatment plant in Vienna will take place in accordance with the minimum efficiences laid down in the emission regulations as issued in 1991 by the Austrian Federal Office for Agriculture and Forestry. To meet these figures it is necessary to adapt the plant by 2001. The studies on several variants and the evaluation process showed a 2-step technology with partial by-passing of the 1st step to be the optimal solution. For this flexible system a new aeration tank volume of only 210,000 m3 is sufficient. Test-runs with a semi-commercial plant confirmed the correctness of all calculations. Possibilities for further modifications have been considered, e.g. dimensioning of all relevant hydraulic installations up to 24 m3/sec, final purification by sand or flocculant filtration and spare areas for measures after 2015.

Biological treatment of high strength wastewater by fed-batch operation

Biological treatment systems for high strength wastewaters are usually operated in continuous mode such as activated sludge systems. When operated at steady-state, continuous systems result in constant effluent standards. However, in the presence of shock loadings and/or toxic compounds in feed wastewater, system performance drops quite significantly as a result of partial loss of microbial activity. In fed-batch operation, wastewater is fed to the aeration tank with a flow rate determined by effluent standards. In this type of operation, wastewater can be fed to biological oxidation unit intermittently or continuously with a low flow rate without any effluent removal. Feed flow rate is adjusted by measuring COD concentration in the effluent. As a result of intermittent addition of wastewater high COD concentrations and toxic compounds are diluted in large volume of aeration tank and inhibition effects of those compounds are reduced. As a result, biological oxidation of these compounds take place at a much higher rate.

Adaption of the main waste water treatment plant in Vienna to meet Austrian emission regulations

The modification of the main waste water treatment plant in Vienna will take place in accordance with the minimum efficiences laid down in the emission regulations as issued in 1991 by the Austrian Federal Office for Agriculture and Forestry. To meet these figures it is necessary to adapt the plant by 2001. The studies on several variants and the evaluation process showed a 2-step technology with partial by-passing of the 1st step to be the optimal solution. For this flexible system a new aeration tank volume of only 210,000 m3 is sufficient. Test-runs with a semi-commercial plant confirmed the correctness of all calculations. Possibilities for further modifications have been considered, e.g. dimensioning of all relevant hydraulic installations up to 24 m3/sec, final purification by sand or flocculant filtration and spare areas for measures after 2015.

Treatment of Citric Acid Wastewater for High Quality Effluent on the Anaerobic-Aerobic Route

A large citric acid factory is situated close to a rather small river, so the discharge of its wastewater caused severe water quality problems. A highly concentrated stream holds more than 90% of the total COD-load, the lowly concentrated stream about 80% of the flow. Anaerobic pretreatment of the highly polluted stream and additional aerobic treatment of all wastewater reduces the total costs to less than one third in comparison to the aerobic treatment alone. The anaerobic treatment is linked with several problems like high sulphate, high ammonia and high calcium concentration leading to H2S and NH3 toxicity as well as calcium carbonate precipitation, about 3 times more than biomass growth. A special anaerobic reactor (EKJ-reactor) was designed to realize an equal distribution of the wastewater in the sludge bed and to prevent sludge and lime deposition. In 1986 the first stage of the full scale treatment plant for the high concentrated wastewater consisting of an equalization tank, an anaerobic reactor (10 000 m3) and a highly loaded activated sludge plant (2 000 m3) went into operation. In 1987 a second anaerobic reactor was built. In 1988 an additional activated sludge plant with simultaneous nitrification-denitrification (aeration tank volume 15 000 m3) for treatment of all the wastewater was designed in order to keep the effluent concentrations within the strict effluent limits. This plant went in operation in 1990. The anaerobic reactors have shown very good results throughout all the five years of operation. At a COD loading rate of 3 to 7kg/m3·d) a COD removal of almost 90% could be achieved. Because of the high COD removal rate of the anaerobic stage, nitrification occurred in the first post-treatment plant but only to nitrite due to high ammonia concentration and high pH. In the second activated sludge plant stable nitrification was obtained. The content of NH4-N as well as NO2-N in the effluent is generally less than 2 mg/l. Some highly concentrated wastewater is fed directly into the second stage in order to obtain rather complete denitrification. So the NO3-N-concentration in the effluent can be kept below 20 mg/l (85% nitrogen removal) mostly.

The Staging of Large Wastewater Treatment Plants - A “Modular” Approach

The primary driving force for re-investments in wastewater treatment plants in Austria - and also other countries in Central Europe - is at present not an increase in load to treatment but a marked increase in effluent requirements to be fulfilled. (The re-investments necessary for sludge handling and treatment remain outside this paper.) Within a period of 20 years, the load specific requirements on aeration tank volume rose five- to tenfold, when Lv = 2.0 kg BOD5/(m3d) was the starting value, and roughly doubled for final clarifiers. In addition, the importance of the application and expansion of primary sedimentation decreased as well. This development over time in Central European countries as well as the need to utilize previous investments as long as possible - 35 to 60 years for civil works are common as periods of depreciation - indicate that investments in new plant at any location in the world have to consider the possible whole life cycle of a plant and that plant hydraulics becomes the “key hook” for expandability.

Optimal design of single and multiple stage activated sludge processes

The present paper describes a rational approach to minimum cost design of an integrated activated sludge process which includes activated sludge reactor, secondary clarifier and sludge recycle. The cost of anaerobic digestion of excess sludge produced is also considered. Procedures for optimal design of both single and multiple stage activated sludge processes, considering construction and operational costs are developed. Biomass concentration in aeration tank and return sludge are utilized as the primary independent design variables to which system performance is related for single stage process. In the multiple stage process, additional design variables (flow and volume fractions for each stage) are included in design vector. Liquid-biomass separation is based on the batch solids flux theory. The optimization problem is framed as minimization of capital and operating cost subject to the constraints determined by effluent quality criteria and process variables affecting the performance. The interior penalty function method is used. Results definitely favor the application of multiple stage process over single stage. The major factor which appears to be contributing to reduction in cost is the biological solids retention time and hence the aeration tank volume.

Kinetic Aspects of Planning and Operating Activated Sludge Systems

A “black-box” substrate removal model for predicting effluent pollution level in activated sludge treatment plants is presented. Reliability of the data acquired from batch and continuously operated systems has been studied. The dependence of the rate of substrate consumption on the quality and concentration of the substrates as well as on the adaptation and concentration of the microflora is shown by using a model sewage containing anion-active detergent as the sole carbon source. Prediction of the continuous operation on the basis of batch experiments is less tedious. The data acquired by the continuous method presented proved to be, however, more reliable and, therefore, preferable in predicting the operation of treatment plants. The method of planning on the basis of the model is illustrated by using an industrial type model sewage: diluted milk containing n-dodecylbenzene sulphonic acid (LAS) as a selectively detectable substrate. The dependence of the aeration tank volume on the biodegradabi1ity and planned effluent level of the different substrates is demonstrated. In the case of poorly biodegradable sewage applied, recycle ratio proved to be a potential control parameter of activated sludge wastewater treatment, extremely useful in overcoming shock loadings .

Operation and Performance of a New Activated Sludge Process: The Contact Stabilization Extended Aeration Hybrid

In this study the operation and performance of a contact stabilization process operating under the extended aeration mode is examined. Data was obtained during a detailed plant study carried out at a full scale municipal wastewater treatment plant. This new hybrid activated sludge process has good process stability like the conventional extended aeration process, but achieves this with a significantly smaller aeration tank volume and therefore lower cost.