Practical Application of the ADUF Process to the Full-Scale Treatment of a Maize-Processing Effluent

1992 ◽  
Vol 25 (10) ◽  
pp. 27-39 ◽  
Author(s):  
W. R. Ross ◽  
J. P. Barnard ◽  
N. K. H. Strohwald ◽  
C. J. Grobler ◽  
J. Sanetra
Keyword(s):  
Membrane Separation ◽  
Wide Spectrum ◽  
Industrial Effluents ◽  
Full Scale ◽  
Permeate Flux ◽  
Practical Application ◽  
Chemical Cleaning ◽  
Treated Effluent ◽  
Solids Concentration ◽  
Load Rate

ADUFR (anaerobic digestion ultrafiltration) is a membrane-assisted process for positive separation of biomass from the treated effluent. Pilot and full-scale ADUFR studies were carried out on a maize-processing effluent (15 kgCOD/m3) at the Meyerton mill of Messrs. African Products, South Africa. The results after 15 months of full-scale operation have illustrated the merits of the process for the production of a colloid-free effluent at a mean COD removal efficiency of 97%. The permeate flux varied in the range 37 to 8 l.m−2.h−1 at 35°C, inlet pressure of 450 kPa, linear tube velocity of 1.6 m/s and digester suspended solids concentration of 21 kg/m3. Periodic chemical cleaning of the unsupported tubular polyethersulphone membranes with EDTA was only commenced after 13 months operation. A mean plant space load rate of 3 kgCOD.m−3.d−1 guaranteed reliability to withstand high COD shock loadings due to variations in the feed load. Bio-membrane separation technology of this nature holds important economic advantages for the treatment of a wide spectrum of organic industrial effluents.

Application of the ADUFR Process to Brewery Effluent on a Laboratory Scale

1992 ◽  
Vol 25 (10) ◽  
pp. 95-105 ◽  
Author(s):  
N. K. H. Strohwald ◽  
W. R. Ross
Keyword(s):  
Membrane Fouling ◽  
Membrane Surface ◽  
Rest Period ◽  
Substantial Effect ◽  
Test Period ◽  
High Rate ◽  
Chemical Cleaning ◽  
Solids Concentration ◽  
Load Rate ◽  
Brewery Effluent

The application of the high rate ADUFR (Anaerobic Digestion - Ultrafiltration) process to brewery effluent was investigated over an 80 day test period. Performance data on both the anaerobic digester and ultrafiltration unit is presented. At stabilised conditions, space load rates of 15 kgCOD.m−3.d−1 could be achieved at hydraulic residence times of 0.5-0.8 days, with COD removal efficiencies between 96 and 99%. Linear flow velocity across the membrane surface and suspended solids concentration of the biomass were found to have a substantial effect on ultrafiltration membrane flux. No membrane fouling was experienced throughout the test period and flux values of 10-18 l.m−2.h−1 (LMH) could be maintained without resorting to chemical cleaning. Dormant sludge was reactivated rapidly, after a two month rest period. A space load rate of 8 kgCOD.m−3.d−1 at a retention time of 0.5 days could be reached within seven days from restart.

Ragging phenomenon characterisation and impact in a full-scale MBR

2013 ◽  
Vol 67 (4) ◽  
pp. 810-816 ◽  
Author(s):  
S. Gabarrón ◽  
M. Gómez ◽  
H. Monclús ◽  
I. Rodríguez-Roda ◽  
J. Comas
Keyword(s):  
Membrane Surface ◽  
Full Scale ◽  
Permeate Flux ◽  
Chemical Cleaning ◽  
Capillary Suction ◽  
Acid Recovery ◽  
Pre Treatment ◽  
Pass Through ◽  
Cleaning Methods ◽  
Treatment Improvement

Although there are few studies about clogging phenomenon in the peer-reviewed literature, it is considered one of the main operational challenges by membrane bioreactor (MBR) practitioners. This study presents data from the performance of a full-scale MBR affected by clogging, and ragging in particular. An evaluation of the efficiencies of different applied cleaning methods revealed the acid recovery cleaning to be more efficient than the basic recovery cleanings, although all maintenance cleanings were largely ineffective in recovering membrane permeability. Only declogging cleaning through the manual removal of the accumulated solids was found to be efficient, indicating that such solids were substantially unremoved by chemical cleaning. Moreover, reclogging following manual cleaning demonstrated a propensity for rapid clogging – within a period of 10 days over which the permeability returned to 68 and 88% of the pre-cleaned state. The analysis of the feedwater indicated suspended textile fibres (>70% cotton) to be present at a concentration of more than 40 mg·L−1, ∼90% being smaller than 1 mm (0.06–0.4 mm). These small lengths of filaments evidently pass through pre-treatment and are retained on the membrane surface, forming ‘rags’ within the membrane module, notwithstanding the routine high quality of sludge reflected in the capillary suction time and filterability measurements. Pre-treatment improvement, manual cleaning and permeate flux reduction are the only options to minimise ragging impact over MBR performance.

Optimisation of coagulation and chlorination in drinking water treatment: laboratory and full-scale studies

2002 ◽  
Vol 2 (2) ◽  
pp. 131-137
Author(s):  
N.D. Basson ◽  
C.F. Schutte
Keyword(s):  
Water Quality ◽  
Large Fraction ◽  
Drinking Water Treatment ◽  
Agricultural Runoff ◽  
Treatment Costs ◽  
Full Scale ◽  
Raw Water ◽  
Activated Carbon Adsorption ◽  
Treated Effluent ◽  
Quality Optimisation

The paper deals with laboratory and full-scale studies aimed at optimising treatment processes at the Balkfontein plant of Sedibeng Water in South Africa. The raw water is highly eutrophic and contains a large fraction of treated effluent from domestic and industrial sources as well as agricultural runoff. The eutrophic nature and changing raw water quality give rise to many operational difficulties and high treatment costs as well as problems with the final water quality. Optimisation of the coagulation and chlorination processes was seen as a cheaper solution to these problems than to install advanced processes such as ozonation and activated carbon adsorption that would add greatly to treatment costs. The laboratory studies indicated that through optimisation of coagulation-flocculation and by replacement of pre-chlorination by intermediate chlorination (after primary sedimentation) most of the treatment problems could be solved and final water of the required quality produced without a large increase in treatment costs.

Membrane thickening of water works sludge

2001 ◽  
Vol 1 (5-6) ◽  
pp. 215-220
Author(s):  
A. Gillighan ◽  
S.J. Judd ◽  
R. Eyres
Keyword(s):  
Hydraulic Resistance ◽  
Reasonable Agreement ◽  
Chemical Cleaning ◽  
Solids Concentration ◽  
Significant Difference ◽  
Layer Resistance ◽  
Tubular Membranes ◽  
Resistance Data ◽  
Mechanical Cleaning ◽  
Dynamic Layer

The efficacy of ultrafiltration (UF) and microfiltration (MF) membranes was assessed for the concentration of actual waterworks sludges using crossflow tubular membranes operated at constant trans-membrane pressure. The MF membrane gave higher initial fluxes than the UF membrane but after 10 min of filtration the flux value and its decline tended to be very similar for both membranes operating under the same conditions. All membranes gave permeate product water of <0.2 NTU and <100ppb coagulant at all times. For both membranes mechanical cleaning, with sponge balls, was at least as effective as acid chemical cleaning, indicating that no significant permanent internal fouling occurred for these membrane materials. Hydraulic resistance data indicated a significant difference in the dynamic layer resistance between the two membranes. Whilst the UF membrane had a hydraulic resistance 3.7 times that of the MF membrane, the dynamic layer formed on the UF membrane during operation displayed a maximum hydraulic resistance almost nine times lower than that of the MF membrane operating under the same conditions. Correlation of cake resistance R versus feed solids concentration C for all the data generated for t>0 demonstrated reasonable agreement with the expression R∝ca where a=0.37 in the current study. This trend has been recorded in previous reported studies, a varying between 0.33 and 0.62 depending on sludge dewaterability.

scholarly journals Experimental Investigation on Floating Solar-Driven Membrane Distillation Desalination Modules

Membranes ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 304
Author(s):  
Qingxiu Miao ◽  
Yaoling Zhang ◽  
Shuo Cong ◽  
Fei Guo
Keyword(s):  
Power Source ◽  
Membrane Distillation ◽  
Small Scale ◽  
Sea Waves ◽  
Permeate Flux ◽  
Practical Application ◽  
Rejection Ratio ◽  
Cold Source ◽  
Mild Temperature ◽  
Feed Temperature

Membrane distillation (MD) processes need a relatively mild temperature gradient as the driving force for desalination. In the field, it is reasonable to utilize solar energy as the heat source for the feed, and seawater as the infinite cold source for condensation. Solar-driven MD provides a route for the practical application of seawater desalination at a small scale. In this work, we focus on floating MD modules with a solar heating bag as the power source, and perform proof-of-principle experiments on the MD performance under various conditioning parameters, including feed flow rate, feed temperature, salinity, air gap, and sea waves. The results indicate that floating solar-driven MD modules are feasible in terms of permeate flux and salt rejection ratio, and the upward evaporation MD configuration leads to a better performance in terms of permeate flux. The simulation and experiments also show that the natural sea waves disturb the heating bag and the MD module floating on the surface of seawater, and effectively enhance the feed circulation and transport in the system.

Application of neural networks in membrane separation

2020 ◽  
Vol 36 (2) ◽  
pp. 265-310 ◽  
Author(s):  
Morteza Asghari ◽  
Amir Dashti ◽  
Mashallah Rezakazemi ◽  
Ebrahim Jokar ◽  
Hadi Halakoei
Keyword(s):  
Neural Networks ◽  
Chemical Engineering ◽  
Membrane Separation ◽  
Mechanistic Model ◽  
Computing Time ◽  
Permeate Flux ◽  
Practical Applications ◽  
Advantages And Disadvantages ◽  
Wide Range ◽  
Physical And Chemical

AbstractArtificial neural networks (ANNs) as a powerful technique for solving complicated problems in membrane separation processes have been employed in a wide range of chemical engineering applications. ANNs can be used in the modeling of different processes more easily than other modeling methods. Besides that, the computing time in the design of a membrane separation plant is shorter compared to many mass transfer models. The membrane separation field requires an alternative model that can work alone or in parallel with theoretical or numerical types, which can be quicker and, many a time, much more reliable. They are helpful in cases when scientists do not thoroughly know the physical and chemical rules that govern systems. In ANN modeling, there is no requirement for a deep knowledge of the processes and mathematical equations that govern them. Neural networks are commonly used for the estimation of membrane performance characteristics such as the permeate flux and rejection over the entire range of the process variables, such as pressure, solute concentration, temperature, superficial flow velocity, etc. This review investigates the important aspects of ANNs such as methods of development and training, and modeling strategies in correlation with different types of applications [microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), reverse osmosis (RO), electrodialysis (ED), etc.]. It also deals with particular types of ANNs that have been confirmed to be effective in practical applications and points out the advantages and disadvantages of using them. The combination of ANN with accurate model predictions and a mechanistic model with less accurate predictions that render physical and chemical laws can provide a thorough understanding of a process.

Research on in situ continuous off-line chemical cleaning in full-scale membrane bioreactors

2018 ◽  
Vol 4 ◽  
pp. 186-192 ◽  
Author(s):  
Liwei Liu ◽  
Jin Tian ◽  
Chunhui Luo ◽  
Chunsheng Chen ◽  
Jicheng Liu ◽  
...  
Keyword(s):  
Membrane Bioreactors ◽  
Full Scale ◽  
Chemical Cleaning

A Wall Film Model for Membrane Fouling

2018 ◽  
Author(s):  
Sina Jahangiri Mamouri ◽  
Volodymyr V. Tarabara ◽  
André Bénard
Keyword(s):  
Multiphase Flow ◽  
Membrane Fouling ◽  
Oil And Gas ◽  
Membrane Separation ◽  
Film Formation ◽  
Membrane Surface ◽  
Permeate Flux ◽  
Water Separation ◽  
Wall Film ◽  
Oil Water

Deoiling of produced or impaired waters associated with oil and gas production represents a significant challenge for many companies. Centrifugation, air flotation, and hydrocyclone separation are the current methods of oil removal from produced water [1], however the efficiency of these methods decreases dramatically for droplets smaller than approximately 15–20 μm. More effective separation of oil-water mixtures into water and oil phases has the potential to both decrease the environmental footprint of the oil and gas industry and improve human well-being in regions such as the Gulf of Mexico. New membrane separation processes and design of systems with advanced flow management offer tremendous potential for improving oil-water separation efficacy. However, fouling is a major challenge in membrane separation [2]. In this study, the behavior of oil droplets and their interaction with crossflow filtration (CFF) membranes (including membrane fouling) is studied using computational fluid dynamics (CFD) simulations. A model for film formation on a membrane surface is proposed for the first time to simulate film formation on membrane surfaces. The bulk multiphase flow is modeled using an Eulerian-Eulerian multiphase flow model. A wall film is developed from mass and momentum balances [3] and implemented to model droplet deposition and membrane surface blockage. The model is used to predict film formation and subsequent membrane fouling, and allow to estimate the actual permeate flux. The results are validated using available experimental data.

scholarly journals Investigating the effects of different cationic charge flocculation polymers on municipal wastewater sludge dewatering

2021 ◽  
Author(s):  
Megan Abrahams ◽  
Mujahid Aziz ◽  
Godwill Kasongo
Keyword(s):  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Operating Cost ◽  
Wastewater Sludge ◽  
Municipal Wastewater Treatment ◽  
Bench Scale ◽  
Treated Effluent ◽  
Solids Concentration ◽  
Municipal Wastewater Treatment Plants ◽  
Polymer Flocculant

Abstract The minimization of sludge produced by municipal wastewater treatment plants (MWWTPs) is critical as its handling accounts for approximately 50% of the total operating cost. The challenges in predicting dewatering performance can be overcome by optimizing the sludge treatment process, especially conditioning and dewatering. This study aimed to investigate sludge dewaterability at four different MWWTPs, using a gravity drainage test unit and a bench-scale press. The effect of differently treated effluent used as a solvent to mix the flocculation polymers was observed during dewatering. The membrane bioreactor (MBR) treated effluent yielded the highest filtrate volume in the lowest amount of time, with the least polymer flocculant dosage. The Box Behnken Design model fitted the data and proved a relationship between polymer dosage, cake solids concentration, and cake height during the bench-scale press tests.

scholarly journals Low- and High-Pressure Membrane Separation in the Production of Process Water for Coke Quenching

Membranes ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 937
Author(s):  
Anna Trusek ◽  
Maciej Wajsprych ◽  
Andrzej Noworyta
Keyword(s):  
High Pressure ◽  
Membrane Filtration ◽  
Membrane Separation ◽  
Coke Oven ◽  
Industrial Plant ◽  
Operating Pressure ◽  
Permeate Flux ◽  
Final Treatment ◽  
Stage System ◽  
Pressure Plant

Although the time for operating mines and coking plants in many countries is coming to an end due to climate change, we must still ensure that the pollution generated by this source of the economy is minimized. Despite the several stages of treatment of the coke-oven effluent, completed with nitrification and denitrification processes preceding final sedimentation, the stream obtained does not meet the requirements of water for coke quenching. That is why the stream after biodegradation and sedimentation was treated on membrane units to ensure water reusing in the coking plant. As the subjected stream contained both solid and dissolved pollutants, a two-stage system was proposed: low- and high-pressure membrane filtration. Industrial modules were tested on pilot units operating under industrial plant conditions. In the case of the ultrafiltration process, all the tested ultrafiltration modules fulfilled the primary task. All of them separated almost completely the turbidities present in the stream, which would have disturbed the operation of the high-pressure plant. Considering the decrease in permeate flux and the possibility of cleaning, a PCI membrane made of PVDF tubes with a diameter of 12.5 mm and pore size of 20 μm was selected. Regarding the high-pressure membrane filtration, the reverse osmosis membrane was significantly better in the removal efficiency of both organic and inorganic dissolved substances. An operating pressure of 3 MPa was chosen for the system. Hence, membrane processes, which are not used as stand-alone treatment units for coke-oven effluents, function well as a final treatment stage.

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