scholarly journals Assessing pollution removal efficiencies of some selected parameters by applying different remediation techniques for petroleum oily sludge

2021 ◽  
pp. 100268
Author(s):  
Anindita Bhattacharya ◽  
Dixita Phukan ◽  
Sunandan Baruah ◽  
Arnab Sarkar ◽  
Prabal Sarkar
Keyword(s):  
Oily Sludge ◽  
Removal Efficiencies ◽  
Pollution Removal

scholarly journals A comparative examination of MBR and SBR performance for municipal wastewater treatment

2021 ◽  
Author(s):  
S. Kitanou ◽  
H. Ayyoub ◽  
J. Touir ◽  
A. Zdeg ◽  
S. Benabdallah ◽  
...  
Keyword(s):  
Membrane Bioreactor ◽  
Municipal Wastewater ◽  
Membrane Separation ◽  
Batch Reactor ◽  
Oxygen Demand ◽  
Superior Performance ◽  
Municipal Wastewater Treatment ◽  
Removal Efficiencies ◽  
Pollution Removal ◽  
Comparative Examination

Abstract In this study, the performance of the membrane bioreactor (MBR) and anoxic–aerobic sequencing batch reactor (SBR) are compared in treating municipal wastewater. The aim of the work was to determine the feasibility of thus systems for the removal of organics matter and nutriments from the municipal wastewater. The MBR displayed a superior performance with removal efficiencies exceeding 99% for TSS, 94% for chemical oxygen demand (COD) and an improvement on SBR efficiencies was found. In the same way, the MBR produced an effluent with much better quality than SBR in terms of total nitrogen (TN) and total phosphorus (TP) removal efficiencies. Combining membrane separation and biodegradation processes or the membrane bioreactor (MBR) technology improved pollution removal efficiencies significantly.

Uncertainty in air stripping tower design: implications of the air-to-water ratio

2001 ◽  
Vol 1 (4) ◽  
pp. 177-184
Author(s):  
B.I. Dvorak ◽  
J.W. Schauble
Keyword(s):  
Mass Transfer ◽  
Removal Efficiency ◽  
Cost Effective ◽  
Air Stripping ◽  
Henry's Constant ◽  
True Value ◽  
Risk Of Failure ◽  
Process Failure ◽  
Removal Efficiencies ◽  
Water Ratio

Environmental engineers are frequently faced with uncertainty in making design decisions because the true value of many process parameters is unknown. In this study, the design of countercurrent air stripping towers was modeled using fuzzy numbers, taking into account uncertainties in mass transfer and Henry's constant. It was found that, in addition to cost, the risk of failure is an important design consideration for stripping tower design. A significant over-design is both cost-effective and results in less risk of design failure. The air-to-water ratio that yielded the least risk of failure switched from low to high as the removal efficiency of the tower increased. An important result is that at lower removal efficiencies, tower design and operation is most sensitive to uncertainties in mass transfer and at higher removal efficiencies, tower design and operation is most sensitive to uncertainties in Henry's constant . The implication is that low air-to-water ratios are best when the regulatory target removal efficiency is low and/or when the uncertainty in the value of the contaminant's Henry's constant is larger than the uncertainty in the mass transfer coefficient value. Otherwise a high air-to-water ratio results in the least risk of process failure.

Pilot Scale Testing of a New Radium-226 Removal Process

1985 ◽  
Vol 20 (2) ◽  
pp. 55-67
Author(s):  
W.B. Anderson ◽  
P.M. Huck ◽  
T.M.R. Meadley ◽  
T.P. Hynes
Keyword(s):  
Treatment Process ◽  
No Reduction ◽  
High Surface ◽  
High Surface Area ◽  
Barium Chloride ◽  
Pilot Scale ◽  
Activity Levels ◽  
New Process ◽  
Removal Efficiencies ◽  
New Treatment

Abstract This paper describes the on-going pilot scale development of a new treatment process designed to remove radium-226 from uranium milling effluents. Presently, decants from Canadian uranium mining and milling tailings areas are treated with barium chloride to remove radium-226 prior to discharge into the environment. This is usually accomplished in large natural or man-made ponds which provide an opportunity for a (Ba,Ra)SO4 precipitate to form and subsequently settle. Sand filtration is sometimes used as a polishing step. This new process differs from conventional and other experimental processes in that it involves the use of a fluidized bed to facilitate the deposition of a (Ba,Ra)SO4 precipitate on a granular medium of high surface area. As a stand-alone treatment process, the new process is consistently able to reduce incoming radium-226 activity levels by 90-99%. Effluent levels of 10 pCi/L (0.370 Bq/L) or less have been achieved, depending on the influent activity levels. Recent testing of the process as a polishing step has demonstrated radium removal efficiencies up to 60% when the process influent was already less than 5 pCi/L (0.185 Bq/L). The process has been operated at temperatures ranging from 26°C down to 0.3°C with no reduction in efficiency. In contrast to treatment times in the order of days for conventional settling pond systems and hours for mechanical stirred tank/filtration systems, the new process is able to achieve these radium removal efficiencies in times on the order of one minute.

Radon removal by aeration: observations on testing, installation and maintenance of domestic treatment units

2009 ◽  
Vol 9 (4) ◽  
pp. 469-475
Author(s):  
T. Turtiainen
Keyword(s):  
Water Quality ◽  
Water Flow ◽  
Removal Efficiency ◽  
Flow Rate ◽  
Test Protocol ◽  
Household Water ◽  
Medium Flow ◽  
Removal Efficiencies ◽  
Frequent Sampling

Radon is one of the contaminants that sometimes impair the water quality of wells, especially those drilled in bedrock. Domestic radon removal units based on aeration have been commercially available for more than ten years. In order to determine how effectively these units remove radon a new test protocol applying frequent sampling while letting 100 litres of water flow, was developed. This way, removal efficiencies can be more accurately calculated and possible malfunctions detected. Seven models of domestic aerators designed for removing radon from household water were tested. The aerators were based on diffused bubble aeration, spray aeration or jet aeration. The average removal efficiencies for 100 litres with a medium flow rate were 86–100% except for a unit that circulated the aerated water back to the well that had removal efficiency of 80% at the maximum. By conducting a questionnaire study usual problems related to the aeration units were localized and recommendations on maintenance and installation are given accordingly.

Experience from 10 Years Advanced Wastewater Treatment – Technology and Results

1982 ◽  
Vol 14 (1-2) ◽  
pp. 121-133
Author(s):  
C Forsberg ◽  
B Hawerman ◽  
B Hultman
Keyword(s):  
Wastewater Treatment ◽  
Urban Population ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Municipal Wastewater Treatment ◽  
Treatment Technology ◽  
Removal Efficiencies ◽  
Municipal Wastewater Treatment Plants ◽  
Operational Modes ◽  
Polluted Waters

Experience from advanced municipal wastewater treatment plants and recovery of polluted waters are described for the last ten years in Sweden. Except in municipalities with large recipients, the urban population is served by treatment plants with combined biological and chemical treatment. Most of these plants are post-precipitation plants. Several modified operational modes have been developed in order to improve the removal efficiencies of pollutants and to reduce the costs. Results are presented on the recovery of specially investigated lakes with a lowered supply of total phosphorus and organic matter.

Behaviour of Alkylphenol Polyethoxylate Surfactants and of Nitrilotriacetate in Sewage Treatment

1987 ◽  
Vol 19 (3-4) ◽  
pp. 449-460 ◽  
Author(s):  
W. Giger ◽  
M. Ahel ◽  
M. Koch ◽  
H. U. Laubscher ◽  
C. Schaffner ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Sewage Treatment ◽  
Operating Conditions ◽  
Municipal Sewage ◽  
Sludge Treatment ◽  
Loading Rates ◽  
Treatment Conditions ◽  
Physico Chemical ◽  
Treated Sewage ◽  
Removal Efficiencies

Effluents and sludges from several municipal sewage treatment plants in Switzerland were analyzed for nonylphenol polyethoxylates (NPnEO, n=3-20), nonylphenol mono- and diethoxylate (NPlEO, NP2EO), corresponding nonylphenoxy carboxylic acids (NP1EC, NP2EC) and nonylphenol (NP). These chemicals derive from nonionic surfactants of the NPnEO-type, and specific analitical techniques were used to study their behaviour during mechanical-biological sewage and subsequent sludge treatment. The parent NPnEO-surfactants, with concentrations in raw and mechanically treated sewage from 400-2200 mg/m3, were relatively efficiently removed by the activated sludge treatment. The abundances of the different metabolites varied depending on treatment conditions. The refractory nature of NPl/2EO, NP and NPl/2EC was recognized. Both biotransformations and physico-chemical processes determine the behaviour and fate of nonylphenolic substances in sewage treatment. Nitrilotriacetate (NTA) was found in primary effluents at concentrations between 430 and 1390 mg/m3. The various treatment plants showed different removal efficiencies for NTA depending on the operating conditions. Activated sludge treatment with low sludge loading rates and nitrifying conditions removed NTA with efficiencies between 95 and 99%. High sludge loading caused a decrease in NTA removal efficiencies from 70% to 39%.

Treatment of Different Wastewaters from Pulp and Paper Industry in Methane Reactors

1985 ◽  
Vol 17 (1) ◽  
pp. 223-230 ◽  
Author(s):  
P K Latola
Keyword(s):  
Power Plant ◽  
Paper Industry ◽  
Granular Sludge ◽  
Paper Mill ◽  
Pulp And Paper Industry ◽  
Pulp And Paper ◽  
Plastic Foam ◽  
Loading Rates ◽  
Multi Stage ◽  
Removal Efficiencies

A wastewater from an integrated paper mill with a COD of 1200 mg/dm3 was anaerobically treated in a multi-stage reactor. The BOD7 removal efficiencies of 60-75 % were achieved at maximal loading rates of 5-6 kg COD/m3d and HRT of 4-6 hours due to the granular sludge. Industrial sulphite evaporator condensates from Ca- and Na-processes were treated in anaerobic filters containing light gravel, plastic foam and power plant slag as filter media. The BOD7 removals of 78 % on average were achieved at loading rates of 1.8-3.3 kg COD/m3d with Ca-process evaporator condensates and 80 % BOD7 removals were achieved with Na-process condensates at loading rates of 3.5-4.1 kg COD/m3d.

Modelling the performance of anaerobic wastewater stabilization ponds

1995 ◽  
Vol 31 (12) ◽  
pp. 171-183 ◽  
Author(s):  
M. M. Saqqar ◽  
M. B. Pescod
Keyword(s):  
Wastewater Treatment ◽  
Water Temperature ◽  
Removal Efficiency ◽  
Wastewater Treatment Plant ◽  
Suspended Solids ◽  
Treatment Plant ◽  
Pond Water ◽  
Removal Efficiencies ◽  
Wastewater Stabilization Ponds ◽  
Raw Wastewater

The performance of the primary anaerobic pond at the Alsamra Wastewater Treatment Plant in Jordan was monitored over 48 months. Overall averages for the removal efficiencies of BOD5, COD and suspended solids were 53%, 53% and 74%, respectively. An improvement in removal efficiency with increase in pond water temperature was demonstrated. A model, which takes into account the variability of raw wastewater at different locations, has been developed to describe the performance of a primary anaerobic pond in terms of a settleability ratio for the raw wastewater. The model has been verified by illustrating the high correlation between actual and predicted pond performance.

Comparison of lime and alum as oily sludge conditioners

1997 ◽  
Vol 36 (12) ◽  
pp. 117-124 ◽  
Author(s):  
Tay Joo Hwa ◽  
S. Jeyaseelan
Keyword(s):  
Specific Resistance ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Oily Sludge ◽  
Sludge Dewatering ◽  
Capillary Suction ◽  
Sludge Cake ◽  
Solids Content ◽  
Optimum Chemical

Chemical conditioning improves sludge dewatering. Choice of chemical conditioners is very much dependent on the characteristics of the sludges and the type of dewatering devices. Lime, alum, ferric chloride and polyelectrolytes are commonly used chemical conditioners. Anaerobic digested sludge samples collected from a sewage treatment plant with different oil contents varying from 1.8% to 8.0% by weight have been examined in the laboratory to find out their specific resistance, capillary suction time and filter yield. Lime and alum were used separately as conditioners. Different dosages of conditioner varying from 2% to 12% by weight were used to determine the optimum chemical dosage for varying oil contents. Lime dosages of about 6% were found to yield favourable characteristics. Addition of alum decreases the specific resistances and capillary suction times of oily sludges rapidly up to 4% dosages. Alum dosages beyond 4% only increase the solids content in the sludge cake and increase the sludge volume to be handled. A correlation between CST and specific resistance to filtration was established. CST can be measured easily and quickly in the laboratories. Using the CST and the correlation a quick prediction on dewaterability can be established.

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