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.

The Effects of Aluminum Sludge From Water Purification on Municipal Primary Sewage Treatment

1973 ◽  
Vol 8 (1) ◽  
pp. 122-147
Author(s):  
J. D. O’Blenis ◽  
T.R. Warriner
Keyword(s):  
Water Purification ◽  
Pilot Plant ◽  
Suspended Solids ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Phosphate Removal ◽  
Plant Performance ◽  
Alum Sludge

Abstract The current widespread practice of disposal of water filtration plant wastes by direct discharge to receiving waters is coming under critical review by regulatory agencies. Among the alternatives for management of these wastes is the possibility of disposal to sanitary sewer systems. Since a recent nation-wide survey had established alum sludge as the most common waste generated by filtration plants, research was initiated to study the effects of water plant alum sludge on primary sewage treatment. A pilot primary sewage treatment plant was constructed and operated with a raw sewage feed of five litres per minute. A laboratory jar test program was conducted to supplement pilot plant operation. Sludges from two different water purification plants were tested along with alum and combinations of alum and water purification plant sludge for their effects on the removal of suspended solids, chemical oxygen demand (COD) and phosphates. The data showed jar testing to be a good indicator of pilot plant performance. Suspended solids, COD and phosphate removal efficiencies were improved by the addition of the sludges. The phosphate removal capacity of water treatment plant alum sludge was approximately the same as that reported for aluminum hydroxide, or about 1/7 to 1/9 of that determined for alum (as Aluminum). Recycling of the sludges improved phosphate removal performance.

Removal efficiency and methanogenic activity profiles in a pilot-scale UASB reactor treating settled sewage at moderate temperatures

2002 ◽  
Vol 45 (10) ◽  
pp. 243-248 ◽  
Author(s):  
L. Seghezzo ◽  
R.G. Guerra ◽  
S.M. González ◽  
A.P. Trupiano ◽  
M.E. Figueroa ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Retention Time ◽  
Sewage Treatment ◽  
Oxygen Demand ◽  
Granular Sludge ◽  
Pilot Scale ◽  
Cod Removal ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Methanogenic Activity

The performance of a sewage treatment system consisting of a settler followed by an Upflow Anaerobic Sludge Bed (UASB) reactor is described. Mean ambient and sewage temperature were 16.5 and 21.6°C, respectively. Total Chemical Oxygen Demand (CODt) concentration averaged 224.2 and 152.6 mg/L, for raw and settled sewage, respectively. The effluent concentration was 68.5 mgCODt/L. Total and suspended COD removal efficiencies of approximately 70 and 80%, respectively, have been observed in the system at a mean Hydraulic Retention Time (HRT) of 2 + 5 h. Maximum COD removal efficiency was achieved in the UASB reactor when upflow velocity (Vup) was 0.43 m/h (HRT = 6 h). Mean Specific Methanogenic Activity (SMA) and Volatile Suspended Solids (VSS) concentration in the granular sludge bed were 0.11 gCOD-CH4/gVSS.d and 30.0 gVSS/Lsludge, respectively. SMA was inversely related to VSS concentration, and both parameters varied along the sludge bed height. The Solids Retention Time (SRT) in the reactor was 450 days. Sludge characteristics have not been affected by changes of up to one month in Vup in the range 0.28–0.85 m/h (HRT 3–9 h). This system or two UASB reactors in series could be an alternative for sewage treatment under moderate temperature conditions.

Fault detection and diagnosis in liquid chillers

2005 ◽  
Vol 219 (2) ◽  
pp. 117-125 ◽  
Author(s):  
E Rueda ◽  
S. A. Tassou ◽  
I. N. Grace
Keyword(s):  
Fault Detection ◽  
Cost Effective ◽  
Fault Detection And Diagnosis ◽  
Plant Performance ◽  
Outlet Temperature ◽  
Refrigeration Equipment ◽  
On Line ◽  
Detection And Diagnosis ◽  
Microprocessor Technology ◽  
Discharge Pressure

Automated fault detection and diagnosis of refrigeration equipment is important in maintaining efficient performance, reducing energy consumption, and increasing the reliability and availability of these systems. The reducing costs of microprocessor technology and the incorporation of more sophisticated monitoring equipment on to even fairly small refrigeration plant, now makes the introduction of on-line fault detection and diagnosis on refrigeration equipment feasible and cost effective. This paper reports on the development of a fault detection and diagnosis (FDD) system for liquid chillers based on artificial intelligence techniques. The system was designed to monitor plant performance and to detect and diagnose faults through comparison with expected behaviour and previous experience of fault characteristics. The system operates on line in real time on a Java 2 platform and was initially used to detect refrigerant charge conditions. The results indicate that the FDD system developed is able to detect and diagnose fault conditions arising from low or high refrigerant charge correctly, using two parameters as detectors: condenser refrigerant outlet temperature and discharge pressure.

Sewage Treatment by Waste Stabilization Pond Systems

2018 ◽  
Vol 3 (1) ◽  
pp. 7-14
Author(s):  
J. Kenneth, R. S. Suglo
Keyword(s):  
Management Practices ◽  
Sewage Treatment ◽  
Oxygen Demand ◽  
Wastewater Management ◽  
Stabilization Pond ◽  
Waste Stabilization Pond ◽  
Quality Guidelines ◽  
Waste Stabilization ◽  
High Reduction ◽  
Wastewater Samples

Sewage generated in Ghana is commonly discharged into the environment without any form of treatment to reduce the degree ofcontamination and mitigate potential public health and environmental issues. Although some attempts have been made in someparts of Ghana to utilize the waste stabilization pond (WSP) system to treat domestic sewage, the ponds often fail to achievetheir purpose due to lack of basic maintenance and supervision. To assess the utility of the WSP system for treating sewage,wastewater samples were collected from the raw sewage, anaerobic, facultative and maturation ponds of WSPs at Obuasi inGhana, and analyzed for physicochemical and microbiological contaminants. The results show that the final pond effluent meetsrecommended microbiological and chemical quality guidelines. The waste stabilization pond system demonstrates high removalefficiencies of wastewater contaminants. The biochemical oxygen demand, total suspended solids, nitrate and faecal coliformsreduction efficiencies of 97.3%, 97.6%, 83.3% and 99.94% respectively are highly significant, and compare well with reportedremoval efficiencies in the literature. Additionally, the ponds have high reduction efficiencies for heavy metals and pathogenicmicroorganisms. The wastewater treatment system complies with standard wastewater management practices, and provides auseful method for treating and disposing wastewater in Ghana.

Deep Shaft High Rate Aerobic Digestion: Laboratory and Pilot Plant Performance

1981 ◽  
Vol 16 (1) ◽  
pp. 71-90 ◽  
Author(s):  
F. Tran ◽  
D. Gannon
Keyword(s):  
Retention Time ◽  
Oxygen Transfer ◽  
Pilot Plant ◽  
High Rate ◽  
Plant Performance ◽  
High Solids ◽  
Aerobic Digestion ◽  
Volatile Solids ◽  
Solids Content ◽  
High Solids Content

Abstract The Deep Shaft process, originating from ICI Ltd. in the U.K., has been further developed by C-I-L Inc., Eco-Technology Division into an extremely energy efficient, high rate biological treatment process for industrial and municipal wastewaters. The Deep Shaft is essentially an air-lift reactor, sunk deep in the ground (100 - 160 m): the resulting high hydrostatic pressure together with very efficient mixing in the shaft provide extremely high oxygen transfer efficiencies (O.T.E.) of up to 90% vs 4 to 20% in other aerators. This high O.T.E. suggests real potential for Deep Shaft technology in the aerobic digestion of sludges and animal wastes: with conventional aerobic digesters an O.T.E. over 8% is extremely difficult to achieve. This paper describes laboratory and pilot plant Deep Shaft aerobic digester (DSAD) studies carried out at Eco-Research's Pointe Claire, Quebec laboratories, and at the Paris, Ontario pilot Deep Shaft digester. An economic pre-evaluation indicated that DSAD had the greatest potential for treating high solids content primary or secondary sludge (3-7% total solids) in the high mesophilic and thermophilic temperature range (25-60°C) i.e. in cases where conventional digesters would experience severe limitations of oxygen transfer. Laboratory and pilot plant studies have accordingly concentrated on high solids content sludge digestion as a function of temperature. Laboratory scale daily draw and fill DSAD runs with a 5% solids sludge at 33°C with a 3 day retention time have achieved 34% volatile solids reduction and a stabilized sludge exhibiting a specific oxygen uptake rate (S.O.U.R.) of less than 1 mgO2/gVSS/hour, measured at 20°C. This digestion rate is about four times faster than the best conventional digesters. Using Eco-Research's Paris, Ontario pilot scale DSAD (a 160 m deep 8 cm diameter u-tube), a 40% reduction in total volatile solids, (or 73% reduction of biodegradable VS) and a final SOUR of 1.2 mg02/gVSS/hour have been achieved for a 4.6% solids sludge in 4 days at 33°C, with loading rates of up to 7.9 kg VSS/m3-day. Laboratory runs at thermophilic temperatures (up to 60°C) have demonstrated that a stabilized sludge (24-41% VSS reduction) can be produced in retention time of 2 days or less, with a resulting loading rate exceeding 10 kg VSS/m3-day.

Validation of On-line Respiration Meter and its Applications by Computer Simulation

1992 ◽  
Vol 26 (5-6) ◽  
pp. 1355-1363 ◽  
Author(s):  
C-W. Kim ◽  
H. Spanjers ◽  
A. Klapwijk
Keyword(s):  
Steady State ◽  
Activated Sludge ◽  
Respiration Rate ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Mass Balances ◽  
Short Term ◽  
Respiration Rates ◽  
On Line ◽  
Made In

An on-line respiration meter is presented to monitor three types of respiration rates of activated sludge and to calculate effluent and influent short term biochemical oxygen demand (BODst) in the continuous activated sludge process. This work is to verify if the calculated BODst is reliable and the assumptions made in the course of developing the proposed procedure were acceptable. A mathematical model and a dynamic simulation program are written for an activated sludge model plant along with the respiration meter based on mass balances of BODst and DO. The simulation results show that the three types of respiration rate reach steady state within 15 minutes under reasonable operating conditions. As long as the respiration rate reaches steady state the proposed procedure calculates the respiration rate that is equal to the simulated. Under constant and dynamic BODst loading, the proposed procedure is capable of calculating the effluent and influent BODst with reasonable accuracy.

Bioavailability of phosphorus as a tool for efficient P reduction schemes

1998 ◽  
Vol 37 (3) ◽  
pp. 241-247 ◽  
Author(s):  
Peter Gerdes ◽  
Sabine Kunst
Keyword(s):  
Sewage Treatment ◽  
Cost Effective ◽  
Effective Management ◽  
Lower Saxony ◽  
Effective Strategies ◽  
P Balance ◽  
Different Sources ◽  
Total P ◽  
P Sources ◽  
P Bioavailability

The bioavailability of phosphorus from different sources has been evaluated in the catchment area of the River Ilmenau (Lower-Saxony, Germany) by using algal assays. The P bioavailability describes the different potential of P from various sources of supporting eutrophication. Effluents from sewage treatment plants were highly bioavailable (72% of TP) whereas rainwater (26%) and erosion effluents (30%) showed a low bioavailability. In order to develop effective strategies to minimize P inputs into the river, source specific P bioavailability indices were determined and combined with a P balance to calculate inputs of vioavailable P (BAP) instead of total P (TP). It could be shown that the relative importance of the different P sources changes when applying BAP. Measures to reduce P inputs into the River Ilmenau will take P bioavailability into consideration and therefore lead to a more cost-effective management.

Two-step demineralization of shrimp (Pandalus Borealis) shells using citric acid: An environmentally friendly, safe and cost-effective alternative to the traditional approach

2021 ◽  
Author(s):  
Julia Pohling ◽  
Deepika Dave ◽  
Yi Liu ◽  
Wade Murphy ◽  
Sheila Trenholm
Keyword(s):  
Citric Acid ◽  
Hydrochloric Acid ◽  
Environmental Health ◽  
Traditional Approach ◽  
Health And Safety ◽  
Cost Effective ◽  
Environmental Health And Safety ◽  
Pandalus Borealis ◽  
Chitin Extraction ◽  
Cost Effective Alternative

Removal of minerals from crustacean shells during chitin extraction is traditionally achieved using hydrochloric acid. However, the environmental, health and safety concerns of hydrochloric acid have led to investigation of...

A Case Study of Optimizing Combined Cycle Performance at Kalaeloa

2009 ◽  
Author(s):  
Helmer Andersen
Keyword(s):  
Power Plants ◽  
Performance Monitoring ◽  
Combined Cycle ◽  
Plant Performance ◽  
Operational Performance ◽  
Cycle Performance ◽  
Monitoring Tools ◽  
Online Performance Monitoring ◽  
On Line

Fuel is by far the largest expenditure for energy production for most power plants. New tools for on-line performance monitoring have been developed for reducing fuel consumption while at the same time optimizing operational performance. This paper highlights a case study where an online performance-monitoring tool was employed to continually evaluate plant performance at the Kalaeloa Combined Cycle Power Plant. Justification for investment in performance monitoring tools is presented. Additionally the influence of various loss parameters on the cycle performance is analyzed with examples. Thus, demonstrating the potential savings achieved by identifying and correcting the losses typically occurring from deficiencies in high impact component performance.

Comparison of Luffa Cylindrical Sponge and Plastic Sponge as Carriers in Sequencing Batch Biofilm Reactor for Sewage Treatment

2012 ◽  
Vol 518-523 ◽  
pp. 2431-2438
Author(s):  
Ying Zhang Wang ◽  
Shang Hua Zhang ◽  
Chang Qing Pang ◽  
Jie Li
Keyword(s):  
Chemical Oxygen Demand ◽  
Sewage Treatment ◽  
Oxygen Demand ◽  
Suspended Solid ◽  
Biofilm Reactor ◽  
Environment Friendly ◽  
Sequencing Batch Biofilm Reactor ◽  
Removal Efficiencies

Luffa cylindrical sponge and plastic sponge were used as carriers in sequencing batch biofilm reactor (SBBR) for sewage treatment in this paper. The removals of suspended solid (SS), chemical oxygen demand (COD) and NH3-N in sewage were studied. The average removal efficiencies of SS, COD and NH3-N with luffa cylindrical sponge were 96%, 89% and 90%, respectively, while these with plastic sponge were 94%, 83% and 80%, respectively. As a natural, cheap and environment friendly biocarrier, luffa cylindrical sponge was easy to get a biofilm with enriched microbes during the first few days of sewage treatment. It was much more suitable as a carrier than the plastic sponge for SBBR.

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