A Hypolimnetic Aeration System to meet the Hypolimnetic Oxygen Demand by Increasing the Natural Assimilation Capacity of a Reservoir

2020 ◽  
Author(s):  
Serdar Göncü
Keyword(s):  
Oxygen Demand ◽  
Aeration System ◽  
Hypolimnetic Oxygen ◽  
Assimilation Capacity

Hypolimnetic oxygenation: predicting performance using a discrete-bubble model

2001 ◽  
Vol 1 (4) ◽  
pp. 185-191 ◽  
Author(s):  
J.C. Little ◽  
D.F. McGinnis
Keyword(s):  
Negative Impact ◽  
Oxygen Demand ◽  
Oxygen Depletion ◽  
Pilot Scale ◽  
Bubble Plume ◽  
Predicting Performance ◽  
Aeration System ◽  
Hypolimnetic Oxygen ◽  
Hypolimnetic Oxygenation ◽  
Increase Oxygen Demand

Stratification of water-supply reservoirs frequently results in substantial hypolimnetic oxygen depletion with a resulting negative impact on raw water quality. Hypolimnetic oxygenators are used to add oxygen to the hypolimnion without significantly disrupting the thermal density structure. The three most common devices are the airlift aerator, the Speece Cone, and the bubble-plume diffuser. A discrete-bubble model based on fundamental principles has previously been shown to hold considerable promise for predicting the performance of airlift aerators and the Speece Cone. In this paper, we have further verified this model by comparing its predictions to a series of pilot-scale experimental measurements and have also demonstrated its ability, under somewhat idealized conditions, to predict the full-scale performance of a bubble-plume diffuser in a stratified reservoir. The potential for the diffused-bubble aeration system to increase oxygen demand, and the rate at which nitrogen builds up during operation and de-gasses following destratification, are also considered.

scholarly journals Membrane integrated process for advanced treatment of high strength Opium Alkaloid wastewaters

2018 ◽  
Vol 77 (7) ◽  
pp. 1899-1908 ◽  
Author(s):  
Güçlü Insel ◽  
Ahmet Karagunduz ◽  
Murat Aksel ◽  
Emine Cokgor ◽  
Gokce Kor-Bicakci ◽  
...  
Keyword(s):  
Inorganic Nitrogen ◽  
Oxygen Demand ◽  
High Strength ◽  
Complete Removal ◽  
Advanced Treatment ◽  
Treated Effluent ◽  
Aeration System ◽  
Total Inorganic Nitrogen ◽  
Conductivity Parameter ◽  
Activated Sludge Systems

Abstract In this study, an integrated aerobic membrane bioreactor (MBR)-nanofiltration (NF) system has been applied for advanced treatment of Opium processing wastewaters to comply with strict discharge limits. Aerobic MBR treatment was successfully applied to high strength industrial wastewater. In aerobic MBR treatment, a non-fouling unique slot aeration system was designed using computational fluid dynamics techniques. The MBR was used to separate treated effluent from dispersed and non-settleable biomass. Respirometric modeling using MBR sludge indicated that the biomass exhibited similar kinetic parameters to that of municipal activated sludge systems. Aerobic MBR/NF treatment reduced chemical oxygen demand (COD) from 32,000 down to 2,500 and 130 mg/L, respectively. The MBR system provided complete removal of total inorganic nitrogen; however, nearly 50 mgN/L organic nitrogen remained in the permeate. Post NF treatment after MBR permeate reduced nitrogen below 20 mgN/L, providing nearly total color removal. In addition, a 90% removal in the conductivity parameter was reached with an integrated MBR/NF system. Finally, post NF application to MBR permeate was found not to be practical at higher pH due to low flux (3–4 L/m2/hour) with low recovery rates (30–40%). As the permeate pH lowered to 5.5, 75% of NF recovery was achieved at a flux of 15 L/m2/hour.

Municipal waste sludge digestion in an autothermal aerobic sequencing batch reactor

2008 ◽  
Vol 58 (6) ◽  
pp. 1237-1243
Author(s):  
Gregor D. Zupanèiè ◽  
Viktor Grilc ◽  
Milenko Roš ◽  
Nataša Uranjek-Ževart
Keyword(s):  
Batch Reactor ◽  
Oxygen Demand ◽  
Batch Process ◽  
Pilot Scale ◽  
Laboratory Scale ◽  
Pure Oxygen ◽  
Sludge Digestion ◽  
Scale Size ◽  
Aeration System ◽  
Maximum Temperatures

An autothermal aerobic sequencing batch process for sludge digestion and “class A” biosolids production was developed. The process was tested in laboratory and pilot scale size up to 150 PE, which can be considered a full scale size in some cases. In this process the maximum temperatures of 61.2°C and 60.2°C were achieved in laboratory scale in pilot scale equipment, respectively. The degradation efficiency of total chemical oxygen demand of sludge was between 50 and 70%. Similar results were achieved using pure oxygen in laboratory scale and oxygen/air mixture 1:1 by volume. The reactor scale greatly affects the achievement of thermophilic temperature. In smaller sizes the convective heat losses are the prevailing heat sink and the process is unable to produce enough heat to reach thermophilic temperature. Larger systems produce excess heat and can be installed with less intense aeration systems. The limit of air aeration system is at the size of about 500 PE.

Evaluation of upgrading a full-scale activated sludge process integrated with floating biofilm carriers

2014 ◽  
Vol 70 (10) ◽  
pp. 1594-1601 ◽  
Author(s):  
Shijian Ge ◽  
Yunpeng Zhu ◽  
Shuang Qiu ◽  
Xiong Yang ◽  
Bin Ma ◽  
...  
Keyword(s):  
Feeding Rate ◽  
Control Strategies ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Full Scale ◽  
Real Time Control ◽  
Aeration Time ◽  
Time Control ◽  
Aeration System ◽  
And Control

This study evaluated the performance of a full-scale upgrade of an existing wastewater treatment plant (WWTP) with the intermittent cyclic extended aeration system (ICEAS), located in Qingdao, China. The ICEAS system was not able to meet effluent standards; therefore, a series of modifications and control strategies were applied as follows: (1) floating plastic carriers were added to the tank to aid biofilm formation; (2) operation parameters such as mixing and aeration time, feeding rate, and settling time were adjusted and controlled with a real-time control system; (3) a sludge return system and submersible water impellers were added; (4) the aeration system was also improved to circulate carriers and prevent clogging. The modified ICEAS system exhibited efficient organic and nutrient removal, with high removal efficiencies of chemical oxygen demand (89.57 ± 4.10%), NH4+-N (95.46 ± 3.80%), and total phosphorus (91.90 ± 4.36%). Moreover, an annual power reduction of 1.04 × 107 kW·h was realized as a result of these modifications.

Evaluation of Hypolimnetic Oxygen Demand in a Large Eutrophic Raw Water Reservoir, San Vicente Reservoir, Calif.

2007 ◽  
Vol 133 (2) ◽  
pp. 130-138 ◽  
Author(s):  
Marc Beutel ◽  
Imad Hannoun ◽  
Jeff Pasek ◽  
Kristen Bowman Kavanagh
Keyword(s):  
Water Reservoir ◽  
Oxygen Demand ◽  
Raw Water ◽  
Hypolimnetic Oxygen

Process audit and asset assessment using on-line instrumentation

1998 ◽  
Vol 37 (12) ◽  
pp. 55-61
Author(s):  
John B. Watts ◽  
Andrew R. Cavenor-Shaw
Keyword(s):  
Retention Time ◽  
Traditional Approach ◽  
Sewage Treatment ◽  
Oxygen Demand ◽  
Cost Effective ◽  
Plant Performance ◽  
Aeration System ◽  
Accurate Picture ◽  
On Line ◽  
Plant Sampling

The traditional approach to assessing the performance of an Activated Sludge Plant (ASP) is to conduct an expensive and often labour intensive through-plant sampling survey. The results from this kind of survey do not give an accurate picture of the plant performance in real time, and often can be ruined by inaccurate or spoilt analytical results. A new approach to Process Audits has been developed based on on-line instrumentation and remote monitoring. The key equipment required to dynamically monitor the ASP performance is the MSL Respirometer which is used to measure organic loading, required retention time and aeration system requirements. Auto-cleaning, auto-calibrating Dissolved Oxygen sensors are used in conjunction with a Respirometer to assess the aeration system efficiency (actual Kla value) and the maximum oxygen demand (OUR) which can be sustained by the plant. Ultrasonic flow meters are used to determine flow splits and actual plant retention time which is compared to the required retention time measured by the Respirometer. Mixed Liquor Suspended Solids (MLSS) profiles are monitored continuously using a self-cleaning optical sensor, which is used along with Respirometric readings to measure the effect of poor wastage regimes and ingress of inert solids. On-line ammonia, phosphate and nitrate monitors can be used to give information on the diurnal variation of nutrients, related to the loading on the plant. As well as the normal plant operation, the effect of shock loads, storm conditions and sludge liquor returns can all be assessed. All instruments are linked via a serial communications loop to a modern and telephone line. The plant is monitored remotely, making it an unobtrusive survey allowing operations to continue as normal and giving a true picture of the plant performance. This approach has been used on several UK sewage treatment works and has proven to be a cost-effective method. In one case a proposed capital spend on final settlement tanks was shown to be unnecessary; in another case the plant was shown to be unable to support a nitrifying biomass.

scholarly journals Pollution Load Capacity Study on Barito River, South Kalimantan, Indonesia

2018 ◽  
Author(s):  
Tien Zubaidah ◽  
Nieke Karnaningroem ◽  
Agus Slamet ◽  
Muhamad Ratodi
Keyword(s):  
Water Contamination ◽  
Load Capacity ◽  
Oxygen Demand ◽  
Pollution Load ◽  
Organic Contamination ◽  
Domestic Waste ◽  
River Quality ◽  
Assimilation Capacity ◽  
Stream Model ◽  
Pollution Loads

Due to the domestic waste, mining, plantation, agriculture and industrial disposal, Barito river has experienced a very serious water contamination. Therefore the researchers intended to investigate Barito river's ability in accommodating the pollution load in order to improve the river quality. In this article, the Biological Oxygen Demand (BOD) parameter has been selected as an index that reflected the organic contamination, while the QUAL2Kw stream model was used in conjunction with a potential pollutants identification and inventory activities as an effort to calculate the Barito river's ability to contain pollution loads. The results have shown that the Barito river has no longer have assimilation capacity for BOD. We have determined that the distribution of pollutant loads and total quantity controls has been able to help the Barito river water utilization to be more efficient.

A theoretical study on operational condition of hypolimnetic aerators

1996 ◽  
Vol 34 (7-8) ◽  
pp. 211-218 ◽  
Author(s):  
Y. Nakamura ◽  
T. Inoue
Keyword(s):  
Theoretical Basis ◽  
Present Model ◽  
Theoretical Study ◽  
Oxygen Demand ◽  
Sediment Oxygen Demand ◽  
Quantitative Prediction ◽  
Necessary Condition ◽  
Phosphate Release ◽  
Hypolimnetic Oxygen ◽  
Simple Mass

A theoretical basis for the operational condition of hypolimnetic aerators is described. The widely observed increase in hypolimnetic oxygen demand during aeration is ascribed to enhanced sediment oxygen demand due to induced circulation currents. The present model enables quantitative prediction of dissolved oxygen and phosphate concentrations during hypolimnetic aeration. Simple mass balance in the hypolimnoin shows a necessary condition to halt phosphate release. A time scale of changes in oxygen concentration is also discussed. These results will assist in designing an aerator and selecting an optimum operational condition.

scholarly journals Comparison of Methods for Assessing the Assimilation Capacity of the Kazakhstani Sector of the Ili River

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
A. T. Nurseitova ◽  
J. K. Jamalov ◽  
A. A. Azimov ◽  
D. B. Nurseitov ◽  
E. A. Tursunov
Keyword(s):  
Experimental Data ◽  
Inverse Problem ◽  
Optimization Problem ◽  
Oxygen Demand ◽  
River System ◽  
First Order ◽  
Ili River Basin ◽  
Assimilation Capacity ◽  
Biochemical Oxygen Consumption ◽  
Real Experimental Data

A mixed inverse problem for determining the biochemical oxygen demand of water ( L 0 ) and the rate of biochemical oxygen consumption ( k 0 ), which are important indicators of water quality, has been formulated and numerically solved based on real experimental data. The inverse problem is reduced to the optimization problem consisting in minimization of the deviation of the calculated values from the experimental data, which is solved numerically using the Nelder–Mead method (zero order) and the gradient method (first order). A number of examples of processing both model experimental data and field experimental data provided by hydrological stations monitoring pollutants in the Kazakhstani part of the Ili River basin are presented. A mathematical model that adequately describes the processes in the river system has been constructed.

Potential Effect of Methane Oxidation and Nitrification-Denitrification on the Oxygen Budget of Hamilton Harbour

1976 ◽  
Vol 11 (1) ◽  
pp. 101-107 ◽  
Author(s):  
W.J. Snodgrass
Keyword(s):  
Oxygen Demand ◽  
Potential Effect ◽  
Gas Production ◽  
Complete Oxidation ◽  
Gas Bubble ◽  
Nitrogen Gas ◽  
Hamilton Harbour ◽  
Oxygen Budget ◽  
Hypolimnetic Oxygen ◽  
Early Fall

Abstract Samples of gas generated by Hamilton Harbour have been collected at a deep water station (20 m) for four months during the summer and early fall of 1975. Methane and nitrogen are the only significant gases collected at the sediments or at the top of the water column. Methane is lost from the rising gas bubble but nitrogen is not lost. Sources of methane and nitrogen gas production are reviewed. Complete oxidation of the methane lost from the gas bubble represents an oxygen sink of 0.3 gm O2/m2/day. Nitrogen production represents an oxygen sink of 0.1 gm O2/m2/day; this assumes that all nitrogen collected is due to nitrification-denitrification of ammonia produced in the sediments. These sinks are respectively estimated to account for 16–32% and 7–14% of the hypolimnetic oxygen demand. These data provide initial order estimates for two components of the hypolimnetic oxygen demand and a partial basis for construction and calibration of an oxygen model for Hamilton Harbour.

Sign in / Sign up

Export Citation Format

Share Document