scholarly journals Desalination of a local oil refinery effluent to meet discharge limits

2021 ◽  
Author(s):  
◽  
Elorm Obotey Ezugbe
Keyword(s):  
Wastewater Treatment ◽  
Flow Rate ◽  
Industrial Sector ◽  
Oil Refinery ◽  
Solution Flow Rate ◽  
Permeation Flux ◽  
Solution Flow ◽  
Membrane Cleaning ◽  
Refinery Effluent ◽  
Draw Solution

The Sustainable Development Goal Six (SDG 6) – “ensure availability and sustainable management of water and sanitation for all” places huge responsibilities on stakeholders (industry, domestic and agricultural) to prioritize water saving, water reuse and proper wastewater treatment to make potable water accessible everywhere in the world. With the industrial sector consuming nearly 20% of the fresh water available, there is a corresponding generation of large volumes of effluents. This has been projected to increase, as population is skyrocketing and more economies are becoming more industrialized to accommodate the needs of the ever-increasing population. Over the years, stringent effluent discharge limits have been imposed on the industrial sector to minimize the pollution of the receiving environments, especially the water bodies. In addition, wastewater treatment for reuse is being encouraged, which will ease the stress on freshwater resources. The oil refinery industry is noted for the generation of large volumes of effluents. These effluents are heavy laden with toxic and refractory materials as well as high concentrations of salts which pose huge environmental risks and detrimental ripple effects on humans and animals if these effluents are not properly treated before discharge. Unfortunately, the use of conventional treatment methods to treat downstream oil refinery effluent (ORE) has been unsuccessful in the removal of these materials, especially the salts. This research therefore, aimed at desalinating the effluent from the effluent treatment plant (ETP) of a local South African waste oil refinery to meet discharge limits. The ETP, even though successful in the removal of organics (COD, turbidity and colour), consistently records high levels of sulphates, chlorides and carbonates as a result of the source of their raw material and other in-house processes that take place during the treatment process. The study assessed and compared the feasibility of applying three membrane processes, viz forward osmosis (FO), reverse osmosis (RO) and hybrid FO-RO systems in desalinating the ORE. The FO and RO were first run as standalone processes, where models were generated and used to optimize the important factors using the Box-Benhken design (BBD) of response surface methodology (RSM). Based on the optimized conditions, the hybrid FORO was investigated. The basis of comparison was their permeation fluxes, salt rejection and flux recoverability after membrane cleaning. A total of 45 experimental runs were conducted which catered for pure water flux tests of virgin membranes, optimization studies and confirmatory runs. The factors of interest for FO were feed solution flow rate (FS-FR) (7.5 – 9.4 L/h), draw solution flow rate (DS-FR) (7.5 – 9.4 L/h) and draw solution concentration (DS-C) (20, 35 and 50 g/L NaCl). With RO, focus was placed on operating pressure (14 – 18 bar), feed concentration and operating time (4-6 h). The results showed an average permeation flux of 3.64 ± 0.13 L/m2 h, Clenrichment (reverse solute diffusion (RSD)) of 35.5 ± 5.15%, SO4 2- rejection of 100%, CO3 2- rejection of 94.59 ± 0.32 and flux recovery of 86.01 ± 2.66% for FO. For RO, the average permeation flux achieved was 2.29 ± 0.24 L/m2 h, Clrejection efficiency was 90.54 ± 0.81%, SO4 2- rejection efficiency was 95.1%, CO3 2- rejection efficiency was 97.3 ± 0.4 and flux recovery after membrane cleaning was 62.52 ± 2.62%. The FO-RO hybrid process proved unsuccessful due to constraints from the filtration unit. As an intervention to make the hybrid process work, NF was used as the recovery process. However, results show a low permeation flux of 0.69 ± 0.10 L/m2h on average. From the results obtained, it was concluded that RO presents the best desalination option for treating the ORE using low pressure of between 14 – 18 bar. This will require no post treatment and there will be no contamination of feed due to RSD

scholarly journals Comparative Study for Organic and Inorganic Draw Solutions in Forward Osmosis

2017 ◽  
Vol 13 (1) ◽  
pp. 94-102
Author(s):  
Ahmed Faiq Al-Alalawy ◽  
Talib Rashid Abbas ◽  
Hadeer Kadhim Mohammed
Keyword(s):  
Flow Rate ◽  
Water Flux ◽  
Forward Osmosis ◽  
Solution Concentration ◽  
Salt Flux ◽  
Effect Of Temperature ◽  
Solution Flow Rate ◽  
Solution Flow ◽  
Draw Solution ◽  
Reverse Salt Flux

The present work aims to study forward osmosis process using different kinds of draw solutions and membranes. Three types of draw solutions (sodium chloride, sodium formate, and sodium acetate) were used in forward osmosis process to evaluate their effectiveness with respect to water flux and reverse salt flux. Experiments conducted in a laboratory-scale forward osmosis (FO) unit in cross flow flat sheet membrane cell.  Three types of membranes (Thin film composite (TFC), Cellulose acetate (CA), and Cellulose triacetate (CTA)) were used to determine the water flux under osmotic pressure as a driving force. The effect of temperature, draw solution concentration, feed and draw solution flow rate, and membrane types, were studied with respect to water flux. The results showed an increase in water flux with increasing feed temperature and draw solution concentrations In addition, the flux increased with increasing feed flow rate while the flux was inversely proportional with the draw solution flow rate. The results showed that reverse osmosis membranes (TFC and CA) are not suitable for using in FO process due to the relatively obtained low water flux when compared with the flux obtained by forward osmosis membrane (CTA). NaCl draw solution gave higher water flux than other draw solutions and at the same time, revealed higher reverse salt flux.

scholarly journals Process water recovery via forward osmosis: membrane and integrated process development

2020 ◽  
Author(s):  
J. Martin ◽  
G. Kolliopoulos ◽  
V. G. Papangelakis
Keyword(s):  
Energy Consumption ◽  
Flow Rate ◽  
Process Development ◽  
Water Flux ◽  
Forward Osmosis ◽  
Solution Flow Rate ◽  
Structural Parameter ◽  
Water Recovery ◽  
Solution Flow ◽  
Draw Solution

Abstract This work reports on efforts to develop an integrated continuous forward osmosis system for the recovery of water from wastewater streams, highlighting critical process parameters to minimize energy consumption. Forward osmosis experiments were performed using NaCl draw solutions of various concentrations and the intrinsic membrane parameters (water permeability, draw solution permeability, and structural parameter) were then determined via nonlinear regression using MATLAB. The experimental data was then used to validate a theoretical water flux model, which was subsequently applied to simulate the forward osmosis performance under different hydrodynamic conditions using both NaCl and TMA-CO2-H2O (TMA: trimethylamine) draw solutions. Analysis of the energy efficiency of the TMA-CO2 draw solution regeneration stage revealed that the draw solution flow rate has a significant impact on energy consumption. Also, increasing the feed flow rate was found to slightly enhance the water flux up to 2.5%, while having a negligible impact on the downstream regeneration process energy consumption.

Performance Analysis for Pressure Retarded Osmosis: Experimentation With High Pressure Difference and Varying Flow Rate, Considering Exposed Membrane Area

2016 ◽  
Author(s):  
Thomas T. D. Tran ◽  
Keunhan Park ◽  
Amanda D. Smith
Keyword(s):  
Flow Rate ◽  
Pressure Difference ◽  
Water Flux ◽  
Feed Solution ◽  
Solution Flow Rate ◽  
Hydraulic Pressure ◽  
Solution Flow ◽  
Bench Scale ◽  
Pressure Retarded Osmosis ◽  
Draw Solution

Pressure retarded osmosis (PRO) is a process for renewable energy conversion that makes use of a salinity gradient between two bodies of water. A semipermeable membrane separates two solutions: the draw solution, with higher salinity, and the feed solution, with lower salinity. In this study, three system design choices for bench-scale PRO systems were investigated: mesh spacer opening area, hydraulic pressure difference, and relative flow rates. Mesh spacers provide mechanical support to the membrane, but can reduce the water flux. Moreover, the water flux behavior at high hydraulic pressure difference is shown to be nonlinear, departing from the theoretically predicted water flux, which is based on a linear model. The ratio of feed solution flow rate to draw solution flow rate also determines PRO performance. Experimental data from a bench-scale system is used to present design-relevant information for optimizing PRO systems toward higher power densities.

Utilization of Waste of Enzymes Biomass as Biosorbent for the Removal of Dyes from Aqueous Solution in Batch and Fluidized Bed Column

2020 ◽  
Vol 71 (1) ◽  
pp. 1-12
Author(s):  
Salman H. Abbas ◽  
Younis M. Younis ◽  
Mohammed K. Hussain ◽  
Firas Hashim Kamar ◽  
Gheorghe Nechifor ◽  
...  
Keyword(s):  
Experimental Data ◽  
Aqueous Solution ◽  
Particle Size ◽  
Adsorption Capacity ◽  
Fluidized Bed ◽  
Flow Rate ◽  
Fungal Biomass ◽  
Solution Flow Rate ◽  
Maximum Adsorption Capacity ◽  
Solution Flow

The biosorption performance of both batch and liquid-solid fluidized bed operations of dead fungal biomass type (Agaricusbisporus ) for removal of methylene blue from aqueous solution was investigated. In batch system, the adsorption capacity and removal efficiency of dead fungal biomass were evaluated. In fluidized bed system, the experiments were conducted to study the effects of important parameters such as particle size (701-1400�m), initial dye concentration(10-100 mg/L), bed depth (5-15 cm) and solution flow rate (5-20 ml/min) on breakthrough curves. In batch method, the experimental data was modeled using several models (Langmuir,Freundlich, Temkin and Dubinin-Radushkviechmodels) to study equilibrium isotherms, the experimental data followed Langmuir model and the results showed that the maximum adsorption capacity obtained was (28.90, 24.15, 21.23 mg/g) at mean particle size (0.786, 0.935, 1.280 mm) respectively. In Fluidized-bed method, the results show that the total ion uptake and the overall capacity will be decreased with increasing flow rate and increased with increasing initial concentrations, bed depth and decreasing particle size.

scholarly journals Pellet Softening Process for the Removal of the Groundwater Hardness; Modelling and Experimentation

2019 ◽  
Vol 12 (3) ◽  
pp. 135-143 ◽  
Author(s):  
Fatin Abdul_kareem Ashoor ◽  
Amer D. Zmat ◽  
Muthanna H. AlDahhan
Keyword(s):  
Calcium Carbonate ◽  
Removal Efficiency ◽  
Flow Rate ◽  
Solution Flow Rate ◽  
Pellet Size ◽  
Solution Flow ◽  
Bed Height ◽  
Naoh Solution ◽  
Softening Process ◽  
Calcium And Magnesium Ions

A lab scale pellet reactor (PR) was designed and fabricated to carry out extensive investigations on the removal efficiency of the hardness of groundwater.  The groundwater of 2200 – 2600 mg/L hardness was collected from Abdulla Ibnalhassan wells area located at the west desert of Al-Shinafiyah district (70 km to the southwest of Al-Dewaniyah city, Iraq). Both hydrodynamic parameters of the pellet reactor (porosity and fluidized bed height) and the parameters of calcium carbonate crystallization process (calcium carbonate equilibrium, pellet size, and density) were modeled and compared with the experimental results of the lab scale pellet reactor. The comparison showed that fair agreement between modeled and measured results was observed. The removal efficiency of both calcium and magnesium ions were 62.5-99% and 83-99% respectively. The removal efficiency was found to be strongly dependent on pH and the ratio of NaOH solution flow rate to the groundwater flow rate in the pellet reactor.

scholarly journals Encapsulation of Menthol in Beeswax by a Supercritical Fluid Technique

2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
Linjing Zhu ◽  
Hongqiao Lan ◽  
Bingjing He ◽  
Wei Hong ◽  
Jun Li
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Flow Rate ◽  
Saturated Solution ◽  
Narrow Particle Size Distribution ◽  
Solution Flow Rate ◽  
Process Conditions ◽  
Solution Flow ◽  
Expansion Temperature

Encapsulation of menthol in beeswax was prepared by a modified particles from gas-saturated solutions (PGSS) process with controlling the gas-saturated solution flow rate. Menthol/beeswax particles with size in the range of 2–50 μm were produced. The effects of the process conditions, namely, the pre-expansion pressure, pre-expansion temperature, gas-saturated solution flow rate, and menthol composition, on the particle size, particle size distribution, and menthol encapsulation rate were investigated. Results indicated that in the range of studied conditions, increase of the pressure, decrease of the gas-saturated solution flow rate, and decrease of the menthol mass fraction can decrease the particle size and narrow particle size distribution of the produced menthol/beeswax microparticles. An N2-blowing method was proposed to measure the menthol release from the menthol/beeswax microparticles. Results showed that the microparticles have obvious protection of menthol from its volatilization loss.

scholarly journals Neutralization Dialysis for Phenylalanine and Mineral Salt Separation. Simple Theory and Experiment

Membranes ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 171 ◽  
Author(s):  
Anton Kozmai ◽  
Elena Goleva ◽  
Vera Vasil’eva ◽  
Victor Nikonenko ◽  
Natalia Pismenskaya
Keyword(s):  
Amino Acid ◽  
Flow Rate ◽  
Solution Concentration ◽  
Exchange Capacity ◽  
Ion Concentration ◽  
Solution Flow Rate ◽  
Strong Electrolyte ◽  
Mineral Salts ◽  
Solution Flow ◽  
Hydrodynamic Mode

A simple non-steady state mathematical model is proposed for the process of purification of an amino acid solution from mineral salts by the method of neutralization dialysis (ND), carried out in a circulating hydrodynamic mode. The model takes into account the characteristics of membranes (thickness, exchange capacity and electric conductivity) and solution (concentration and components nature) as well as the solution flow rate in dialyzer compartments. In contrast to the known models, the new model considers a local change in the ion concentration in membranes and the adjacent diffusion layers. In addition, the model takes into consideration the ability of the amino acid to enter the protonation/deprotonation reactions. A comparison of the results of simulations with experimental data allows us to conclude that the model adequately describes the ND of a strong electrolyte (NaCl) and amino acid (phenylalanine) mixture solutions in the case where the diffusion ability of amino acids in membranes is much less, than mineral salts. An example shows the application of the model to predict the fluxes of salt ions through ion exchange membranes as well as pH of the desalination solution at a higher than in experiments flow rate of solutions in ND dialyzer compartments.

scholarly journals Surface and Morphological Investigation of Synthesized Nanostructured Ridges from Electrospun Polyvinyl Alcohol-Albumin Blend—A Taguchi Design of Experiment Approach

Fibers ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 29
Author(s):  
Jopeth Ramis ◽  
Bryan Pajarito ◽  
Crisneil Natividad ◽  
Mark Jared Van Ocampo ◽  
Crizaldy Tugade ◽  
...  
Keyword(s):  
Polyvinyl Alcohol ◽  
Flow Rate ◽  
Design Of Experiment ◽  
Surface Characterization ◽  
Taguchi Design ◽  
Root Mean Square Roughness ◽  
Solution Flow Rate ◽  
Radius Of Curvature ◽  
Solution Flow ◽  
Taguchi Design Of Experiment

We report the synthesis of presumably a “nanoridge” from the electrospinning of a hydrophilic polymer–protein blend. The material exhibits vertical elevation from the substrate, distinct from the morphologies seen in electrospinning. It is hypothesized that the formation of the nanostructured ridges is due to the migration of the charged protein to the apex through a highly polarized electric field in electrospinning conditions. In this study, we assessed the polyvinyl alcohol–egg albumin (PVA–EA) system in a solvent comprising of water, formic and acetic acid, together with the tip-to-collector distance (TCD) and solution flowrate. To quantify the factor effects in the surface properties of the material, a Taguchi design of experiment was used. The ridge heights observed ranged from 84.8–639.9 nm, and the material height is predominantly affected by the PVA–EA ratio and solution flow rate. The root mean square roughness was influenced by the TCD and flow rate, which has values ranging from 11.37–57.56 nm. In evaluating the sharpness of the ridge, we used the radius of curvature, where the TCD highly affects the apex sharpness. The work offers not just a likely new class of morphology, but a new perspective on the surface characterization of an electrospun material which could affect the performance of such a use in biological and physical systems.

scholarly journals Investigation on the Regeneration Performance of a New Mixed Liquid Desiccant Solution in Falling Film Regenerator

Proceedings ◽  
2018 ◽  
Vol 2 (22) ◽  
pp. 1374
Author(s):  
Tao Wen ◽  
Dan Zhong ◽  
Yuanhao Wang ◽  
Yimo Luo
Keyword(s):  
Flow Rate ◽  
Solution Temperature ◽  
Solution Flow Rate ◽  
Mixed Solution ◽  
Falling Film ◽  
Liquid Desiccant ◽  
Solution Flow ◽  
Regeneration Rate ◽  
Air Inlet ◽  
Selection Of

The present study firstly developed a new kind of mixed liquid desiccant for the purpose of causticity reduction on metal based regenerator. The formula of the mixed liquid desiccant is 25% LiCl + 39% hydroxyethyl urea + 36% water. Experimental results show that the causticity of the mixed solution is much less severe than that of conventional LiCl solution. The regeneration rate increases with the increase of air flow rate and solution temperature and decreases with the increase of air inlet humidity. The air temperature and solution flow rate has negligible influence on the regeneration performance. The present study provides a practical alternative for the selection of liquid desiccant and also give useful guidance for the design of regenerator.

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