scholarly journals Effect of Primary Variables on A Confined Plunging Liquid Jet Reactor

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 764 ◽  
Author(s):  
Bader S. Al-Anzi
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Air Entrainment ◽  
Operating Conditions ◽  
Liquid Jet ◽  
Entrainment Rate ◽  
Activated Sludge Process ◽  
Gas Entrainment ◽  
Air Entrainment Rate ◽  
Aeration Process

The effects of operating conditions including a novel downcomer geometry on the gas/air entrainment rate, Qa, were investigated for a local vertical confined plunging liquid jet reactor (CPLJR) as an alternative aeration process that is of interest to Kuwait and can be used in various applications, such as in wastewater treatment as an aerobic activated sludge process, fermentation, brine dispenser, and gas–liquid reactions. Operating conditions, such as various downcomer diameters (Dc = 45−145 mm), jet lengths (Lj = 200–500 mm), nozzle diameters (dn = 3.5–15 mm), and contraction angles (Ɵ =20–80°), were investigated. A newly designed downcomer with various mesh openings/pores (Dm = 0.25ʺ (6.35 mm)–1ʺ (25.4 mm)) was also investigated in the current study. The air entrainment results showed that these were the primary parameters for the measured air entrainment rate in confined systems. The highest gas entrainment rates were achieved when the ratio of the downcomer diameter (Dc) to the nozzle diameter (dn) was greater than approximately 5, as long as the liquid superficial velocity was sufficient to carry bubbles downward. Furthermore, a downcomer with mesh openings (Dm) less or equal to 0.5ʺ (12.7 mm) provided a higher entrainment rate than that of conventional downcomer (without a mesh).

scholarly journals Treatment of slaughterhouse wastewater using an activated sludge/contact aeration process

2003 ◽  
Vol 47 (12) ◽  
pp. 285-292 ◽  
Author(s):  
C.-K. Chen ◽  
S.-L. Lo
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Biological Treatment ◽  
Treatment Plant ◽  
Aeration Tank ◽  
Activated Sludge Process ◽  
Two Phase ◽  
Slaughterhouse Wastewater ◽  
Aeration Process ◽  
Biological Treatment System

This study combines a two-phase biological treatment system of activated sludge/contact aeration process by adding biological contact filters into the rear sector of the activated sludge aeration tank of the slaughterhouse wastewater treatment plant. This system keeps the advantages of complete mixing of substrates and microorganisms and flexible operation of the activated sludge process, and increased biological phase, less sludge, process stability and good settleability of sludge of the contact aeration process. This system could avoid the defects of sludge bulking, increased sludge production and difficult operation of the activated sludge process, and system clogging and rigid operation of the contact aeration process. Because suspended microorganisms are flowing into the contact aeration system, which then degrade or suspend within the biological contact filters after being adsorbed by the fixed biological film, on which partial bio-solids will act as seeding microorganisms. Suspended microorganisms and the dropped biological film will settled in the secondary settling tank, then reflux into the activated sludge aeration tank. The partial dropped biological film will decompose in the activated sludge aeration tank to achieve the function of decreasing sludge. Large specific gravity and good settling ability of biofilm sludge will provide better effluent quality. It has been proven through a practical experiment at a slaughterhouse wastewater treatment plant in Taiwan, that the activated sludge process effluent COD value of 150-200 mg/L and SS value of 80-100 mg/L were decreased to around 40 mg/L and 22 mg/L, respectively, after changing its system to the two-phase biological treatment system of activated sludge/contact aeration process.

scholarly journals Wastewater Treatment Plant Operation: Simple Control Schemes with a Holistic Perspective

2020 ◽  
Vol 12 (3) ◽  
pp. 768 ◽  
Author(s):  
S. Revollar ◽  
R. Vilanova ◽  
P. Vega ◽  
M. Francisco ◽  
M. Meneses
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Performance Indicator ◽  
Treatment Plant ◽  
Operating Conditions ◽  
Activated Sludge Process ◽  
Proportional Integral ◽  
Whole Plant ◽  
Global Performance

In this paper, a control approach for improving the overall efficiency of a wastewater treatment plant (WWTP) is presented. It consists of a cascaded control system that uses a global performance indicator as the controlled variable to drive the plant to operating conditions that satisfies trade-offs involved in the WWTP operation, improving the global performance of the plant. The selected global performance indicator is the N/E index that measures the ratio between the amount of nitrogenated compounds eliminated (kgN) and the energy (kWh) required to achieve that goal. This index links the variables of the activated sludge process with the energy consumed in the whole plant, thus the control strategy takes actions based on plantwide considerations. An external Proportional Integral (PI) controller changes the DO set point according to the N/E index and the basic dissolved oxygen (DO) control scheme in the activated sludge process follows this reference changes varying the aeration intensity. An outer loop with an event-based controller is used to compute the index values when the DO concentration is driven to excessively low limits, preventing long operation periods in this undesirable condition. Simple proportional integral controllers (PI) are used to adapt the strategy to the automation systems available in WWTPs. The implementation in the Benchmark Simulation Model 2 (BSM2) demonstrates the potential of the proposed approach. The results show the possibilities of the N/E index to be used as an indicator of global performance of WWTPs. It provides a link between water line objectives and energy consumption in the whole plant that can be exploited to introduce plantwide considerations in alternative control strategies formulated to drive the plant to operating conditions that optimize the overall process efficiency.

Effect of Nozzle Contraction Angle on Air Entrainment Rate of a Vertical Plunging Liquid Jet.

2000 ◽  
Vol 33 (5) ◽  
pp. 805-807 ◽  
Author(s):  
Kazuaki Yamagiwa ◽  
Akira Ito ◽  
Kei Tajima ◽  
Masanori Yoshida ◽  
Akira Ohkawa
Keyword(s):  
Air Entrainment ◽  
Liquid Jet ◽  
Entrainment Rate ◽  
Air Entrainment Rate ◽  
Contraction Angle

DESIGN PLANNING WASTEWATER TREATMENT PLANT OF NATA DE COCO INDUSTRY WITH THE ACTIVATED SLUDGE PROCESS

2016 ◽  
Vol 9 (2) ◽  
Author(s):  
Dinda Rita K. Hartaja ◽  
Imam Setiadi
Keyword(s):  
Waste Water ◽  
Wastewater Treatment ◽  
Activated Sludge ◽  
Waste Water Treatment ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Appropriate Technology ◽  
Waste Water Treatment Plant ◽  
Activated Sludge Process ◽  
High Level

Generally, wastewater of nata de coco industry contains suspended solids and COD were high, ranging from 90,000 mg / l. The high level of of the wastewater pollutants, resulting in nata de coco industry can not be directly disposed of its wastewater into the environment agency. Appropriate technology required in order to process the waste water so that the treated water can meet the environmental quality standards that are allowed. Designing the waste water treatment plant that is suitable and efficient for treating industrial wastewater nata de coco is the activated sludge process. Wastewater treatment using activated sludge process of conventional (standard) generally consists of initial sedimentation, aeration and final sedimentation.Keywords : Activated Sludge, Design, IPAL

Rehabilitation and Upgrading of the Beni Suef City Wastewater Treatment Plant

1990 ◽  
Vol 22 (7-8) ◽  
pp. 131-138
Author(s):  
Ahmed Fadel
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Primary Treatment ◽  
High Rate ◽  
Shock Load ◽  
Economic Evaluations ◽  
Activated Sludge Process ◽  
Trickling Filter

Many of Egypt's cities have existing treatment plants under operation that have been constructed before 1970. Almost all of these treatment plants now need rehabilitation and upgrading to extend their services for a longer period. One of these plants is the Beni Suef City Wastewater Treatment Plant. The Beni Suef WWTP was constructed in 1956. It has primary treatment followed by secondary treatment employing intermediate rate trickling filters. The BOD, COD, and SS concentration levels are relatively high. They are approximately 800, 1100, and 600 mg/litre, respectively. The Beni Suef city required the determination of the level of work needed for the rehabilitation and upgrading of the existing 200 l/s plant and to extend its capacity to 440 l/s at year 2000 A description of the existing units, their deficiencies and operation problems, and the required rehabilitation are presented and discussed in this paper. Major problems facing the upgrading were the lack of space for expansion and the shortage of funds. It was, therefore, necessary to study several alternative solutions and methods of treatment. The choice of alternatives was from one of the following schemes: a) changing the filter medium, its mode of operation and increasing the number of units, b) changing the trickling filter to high rate and combining it with the activated sludge process, for operation by one of several possible combinations such as: trickling filter-solids contact, roughing filter-activated sludge, and trickling filter-activated sludge process, c) dividing the flow into two parts, the first part to be treated using the existing system and the second part to be treated by activated sludge process, and d) expanding the existing system by increasing the numbers of the different process units. The selection of the alternative was based on technical, operational and economic evaluations. The different alternatives were compared on the basis of system costs, shock load handling, treatment plant operation and predicted effluent quality. The flow schemes for the alternatives are presented. The methodology of selecting the best alternative is discussed. From the study it was concluded that the first alternative is the most reliable from the point of view of costs, handling shock load, and operation.

Operational Results of the Wolfsburg Wastewater Treatment Plant

1992 ◽  
Vol 25 (4-5) ◽  
pp. 203-209 ◽  
Author(s):  
R. Kayser ◽  
G. Stobbe ◽  
M. Werner
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Nitrogen Content ◽  
Total Nitrogen ◽  
Nitrogen Removal ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Phosphate Removal ◽  
Total Nitrogen Content ◽  
Activated Sludge Process

At Wolfsburg for a load of 100,000 p.e., the step-feed activated sludge process for nitrogen removal is successfully in operation. Due to the high denitrification potential (BOD:TKN = 5:1) the effluent total nitrogen content can be kept below 10 mg l−1 N; furthermore by some enhanced biological phosphate removal about 80% phosphorus may be removed without any chemicals.

scholarly journals The capacity of wastewater treatment plants drives bacterial community structure and its assembly

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Young Kyung Kim ◽  
Keunje Yoo ◽  
Min Sung Kim ◽  
Il Han ◽  
Minjoo Lee ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Community Structure ◽  
Bacterial Community ◽  
Activated Sludge ◽  
Community Assembly ◽  
Bacterial Communities ◽  
Wastewater Treatment Plants ◽  
High Capacity ◽  
Operating Conditions ◽  
Rrna Gene

Abstract Bacterial communities in wastewater treatment plants (WWTPs) affect plant functionality through their role in the removal of pollutants from wastewater. Bacterial communities vary extensively based on plant operating conditions and influent characteristics. The capacity of WWTPs can also affect the bacterial community via variations in the organic or nutrient composition of the influent. Despite the importance considering capacity, the characteristics that control bacterial community assembly are largely unknown. In this study, we discovered that bacterial communities in WWTPs in Korea and Vietnam, which differ remarkably in capacity, exhibit unique structures and interactions that are governed mainly by the capacity of WWTPs. Bacterial communities were analysed using 16S rRNA gene sequencing and exhibited clear differences between the two regions, with these differences being most pronounced in activated sludge. We found that capacity contributed the most to bacterial interactions and community structure, whereas other factors had less impact. Co-occurrence network analysis showed that microorganisms from high-capacity WWTPs are more interrelated than those from low-capacity WWTPs, which corresponds to the tighter clustering of bacterial communities in Korea. These results will contribute to the understanding of bacterial community assembly in activated sludge processing.

scholarly journals The diversity of active microbial groups in an activated sludge process treating painting process wastewater

2020 ◽  
Vol 148 ◽  
pp. 01002
Author(s):  
Herto Dwi Ariesyady ◽  
Mentari Rizki Mayanda ◽  
Tsukasa Ito
Keyword(s):  
Wastewater Treatment ◽  
Microbial Community ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Activated Sludge ◽  
Biological Treatment ◽  
Rrna Gene ◽  
Activated Sludge Process ◽  
Painting Process ◽  
Process Wastewater

Activated sludge process is one of the wastewater treatment method that is applied for many wastewater types including painting process wastewater of automotive industry. This wastewater is well-known to have high heavy metals concentration which could deteriorate water environment if appropriate performance of the wastewater treatment could not be achieved. In this study, we monitored microbial community diversity in a Painting Biological Treatment (PBT) system. We applied a combination of cultivation and genotypic biological methods based on 16S rRNA gene sequence analysis to identify the diversity of active microbial community. The results showed that active microbes that could grow in this activated sludge system were dominated by Gram-negative bacteria. Based on 16S rRNA gene sequencing analysis, it was revealed that their microbial diversity has close association with Bacterium strain E286, Isosphaera pallida, Lycinibacillus fusiformis, Microbacterium sp., Orchobactrum sp., Pseudomonas guariconensis, Pseudomonas sp. strain MR84, Pseudomonas sp. MC 54, Serpens sp., Stenotrophomonas acidaminiphila, and Xylella fastidiosa with similarity of 86 – 99%. This findings reflects that microbial community in a Painting Biological Treatment (PBT) system using activated sludge process could adapt with xenobiotics in the wastewater and has a wide range of diversity indicating a complex metabolism mechanism in the treatment process.

Sign in / Sign up

Export Citation Format

Share Document