The design of an optimized portable artificial kidney system using recirculation and regeneration of dialysate

1998 ◽  
Vol 212 (5) ◽  
pp. 373-381 ◽  
Author(s):  
R J A Bigsby ◽  
R J Rider ◽  
G N Blount
Keyword(s):  
Activated Carbon ◽  
Small Volume ◽  
Operating Conditions ◽  
Artificial Kidney ◽  
Design Solution ◽  
Peltier Effect ◽  
Prototype System ◽  
Dialysis Session ◽  
Dialysate Volume ◽  
Dialysate Temperature

This paper is intended as an overview of the research carried out at Coventry University in the design of a portable artificial kidney system. It was seen that the key to the problem was the reduction in dialysate volume, and so it was decided to develop a prototype that would utilize the regeneration and recirculation of a small volume of dialysate. A prototype system has been produced and used to simulate a dialysis session. Activated carbon was used as a sorbent for the regeneration of the dialysate, circulating in a closed loop. For the purpose of this work, the adsorption of urea was investigated as this is, volumetrically, the major solute to be removed. Peltier effect cooling was used to vary the dialysate temperature down to 2 °C, as activated carbon will adsorb greater amounts of urea at lower temperatures. A series of tests was then carried out to investigate the effect of dialysate temperature, flowrate and volume on the amount of urea that could be dialysed. From the experimental results, a model of the system was derived, which made it possible to determine the implications of different operating conditions on the overall mass and size of a portable dialysis system. The output of this model was then used to establish a design specification and produce an optimum design solution for the system.

scholarly journals Performance of Iron-Functionalized Activated Carbon Catalysts (Fe/AC-f) on CWPO Wastewater Treatment

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 337
Author(s):  
Sara Mesa Medina ◽  
Ana Rey ◽  
Carlos Durán-Valle ◽  
Ana Bahamonde ◽  
Marisol Faraldos
Keyword(s):  
Wastewater Treatment ◽  
Activated Carbon ◽  
Landfill Leachate ◽  
Surface Composition ◽  
Treatment Plant ◽  
Reaction Medium ◽  
Pollutant Removal ◽  
Operating Conditions ◽  
Water Matrix ◽  
The Stability

Two commercial activated carbon were functionalized with nitric acid, sulfuric acid, and ethylenediamine to induce the modification of their surface functional groups and facilitate the stability of corresponding AC-supported iron catalysts (Fe/AC-f). Synthetized Fe/AC-f catalysts were characterized to determine bulk and surface composition (elemental analysis, emission spectroscopy, XPS), textural (N2 isotherms), and structural characteristics (XRD). All the Fe/AC-f catalysts were evaluated in the degradation of phenol in ultrapure water matrix by catalytic wet peroxide oxidation (CWPO). Complete pollutant removal at short reaction times (30–60 min) and high TOC reduction (XTOC = 80 % at ≤ 120 min) were always achieved at the conditions tested (500 mg·L−1 catalyst loading, 100 mg·L−1 phenol concentration, stoichiometric H2O2 dose, pH 3, 50 °C and 200 rpm), improving the results found with bare activated carbon supports. The lability of the interactions of iron with functionalized carbon support jeopardizes the stability of some catalysts. This fact could be associated to modifications of the induced surface chemistry after functionalization as a consequence of the iron immobilization procedure. The reusability was demonstrated by four consecutive CWPO cycles where the activity decreased from 1st to 3rd, to become recovered in the 4th run. Fe/AC-f catalysts were applied to treat two real water matrices: the effluent of a wastewater treatment plant with a membrane biological reactor (WWTP-MBR) and a landfill leachate, opening the opportunity to extend the use of these Fe/AC-f catalysts for complex wastewater matrices remediation. The degradation of phenol spiked WWTP-MBR effluent by CWPO using Fe/AC-f catalysts revealed pH of the reaction medium as a critical parameter to obtain complete elimination of the pollutant, only reached at pH 3. On the contrary, significant TOC removal, naturally found in complex landfill leachate, was obtained at natural pH 9 and half stoichiometric H2O2 dose. This highlights the importance of the water matrix in the optimization of the CWPO operating conditions.

scholarly journals Simple Design Solution for Harsh Operating Conditions: Redesign of Conveyor Transfer Station with Reverse Engineering and DEM Simulations

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 4008
Author(s):  
Błażej Doroszuk ◽  
Robert Król ◽  
Jarosław Wajs
Keyword(s):  
Reverse Engineering ◽  
Laser Scanning ◽  
Design For Manufacturing ◽  
Operating Conditions ◽  
Design Solution ◽  
Dem Simulations ◽  
Transfer Station ◽  
Transfer Stations ◽  
Dem Model ◽  
Current Operating

This paper addresses the problem of conveyor transfer station design in harsh operating conditions, aiming to identify and eliminate a failure phenomenon which interrupts aggregate supply. The analyzed transfer station is located in a Polish granite quarry. The study employs laser scanning and reverse engineering methods to map the existing transfer station and its geometry. Next, a discrete element method (DEM) model of granite aggregate has been created and used for simulating current operating conditions. The arch formation has been identified as the main reason for breakdowns. Alternative design solutions for transfer stations were tested in DEM simulations. The most uncomplicated design for manufacturing incorporated an impact plate, and a straight chute has been selected as the best solution. The study also involved identifying areas of the new station most exposed to wear phenomena. A new transfer point was implemented in the quarry and resolved the problem of blockages.

scholarly journals Removal of organic pollutants from produced water by batch adsorption treatment

2021 ◽  
Author(s):  
Eman Hashim Khader ◽  
Thamer Jassim Mohammed ◽  
Nourollah Mirghaffari ◽  
Ali Dawood Salman ◽  
Tatjána Juzsakova ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Produced Water ◽  
Oxygen Demand ◽  
Powdered Activated Carbon ◽  
Pollutant Removal ◽  
Operating Conditions ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Zeolite X

AbstractThis paper studied the adsorption of chemical oxygen demand (COD), oil and turbidity of the produced water (PW) which accompanies the production and reconnaissance of oil after treating utilizing powdered activated carbon (PAC), clinoptilolite natural zeolite (CNZ) and synthetic zeolite type X (XSZ). Moreover, the paper deals with the comparison of pollutant removal over different adsorbents. Adsorption was executed in a batch adsorption system. The effects of adsorbent dosage, time, pH, oil concentration and temperature were studied in order to find the best operating conditions. The adsorption isotherm models of Langmuir, Freundlich and Temkin were investigated. Using pseudo-first-order and pseudo-second-order kinetic models, the kinetics of oil sorption and the shift in COD content on PAC and CNZ were investigated. At a PAC adsorbent dose of 0.25 g/100 mL, maximum oil removal efficiencies (99.57, 95.87 and 99.84 percent), COD and total petroleum hydrocarbon (TPH) were identified. Moreover, when zeolite X was used at a concentration of 0.25 g/100 mL, the highest turbidity removal efficiency (99.97%) was achieved. It is not dissimilar to what you would get with PAC (99.65 percent). In comparison with zeolites, the findings showed that adsorption over PAC is the most powerful method for removing organic contaminants from PW. In addition, recycling of the consumed adsorbents was carried out in this study to see whether the adsorbents could be reused. Chemical and thermal treatment will effectively regenerate and reuse powdered activated carbon and zeolites that have been eaten. Graphic abstract

On Pipeline Lateral Buckling: Lessons Learned and Current Design Challenges

2012 ◽  
Author(s):  
Emil A. Maschner ◽  
Basel Abdalla
Keyword(s):  
Cost Effective ◽  
Lessons Learned ◽  
Operating Conditions ◽  
Design Solution ◽  
Lateral Buckling ◽  
Diverse Range ◽  
Applied Loading ◽  
Direct Design ◽  
Safety Margins ◽  
Global Buckling

The subject of lateral buckling design in recent years has by necessity become increasingly more involved as pipeline projects have moved into more difficult environments where there is a need for optimized economic solutions with assured through-life reliability. The authors have had direct design responsibility and specialist involvement with a large number of projects covering a diverse range of environments, single or PIP systems, variable product characteristics and operating conditions, external applied loading type, and geographical installation limitations. These include shallow and deep water, large thin walled and small thick walled diameter pipes, flat to undulating hard to soft seabed, variable cohesive and non-cohesive surficial soil types and various other project considerations which have impacted on the chosen design solution. The purpose of this paper will be to highlight aspects of global buckling design associated with reliable in place systems and conversely those aspects associated with integrity risks to the as-laid operational pipelines. A review of past project challenges along with a commentary as to the state of the art at the time gives an opportunity to evaluate risks and challenges being faced on current projects. Particularly, as it seeks to develop ever more cost effective designs with proven robustness but optimized safety margins for the installation and operation of HT/HP pipelines in marginal fields.

Urban Sludge and the Performance of the System of Wood Activated Carbon Research

2015 ◽  
Vol 730 ◽  
pp. 271-274
Author(s):  
Yan Kun Cheng
Keyword(s):  
Activated Carbon ◽  
Operating Conditions ◽  
Raw Material ◽  
Activated Carbon Adsorption ◽  
Activation Temperature ◽  
Carbon Sample ◽  
Carbon Adsorption ◽  
Treatment Experiment ◽  
Temperature Operating ◽  
Physical And Chemical

In urban sludge and sawdust as raw material,using zinc chloride activation method in the preparation of activated carbon under different operating conditions, through the detection of specific surface area activated carbon sample and methylene blue adsorption value and the iodine adsorption value, studies the impregnation ratio, activation time and activation temperature operating conditions affect the performance of activated carbon sample. Through to the physical and chemical modification of activated carbon,To the preparation of activated carbon adsorption purification treatment experiment was carried out in the discharge of sewage.

Simultaneous Removal of SO2 and NO with Activated Carbon from Sewage Sludge Modified by Chitosan

2012 ◽  
Vol 253-255 ◽  
pp. 960-964 ◽  
Author(s):  
Xiao Dan Fan ◽  
Xiang Kai Zhang
Keyword(s):  
Activated Carbon ◽  
Sewage Sludge ◽  
Active Sites ◽  
Operating Conditions ◽  
Competitive Sorption ◽  
Simultaneous Removal ◽  
No Removal ◽  
Adsorption Capacities ◽  
So2 Adsorption ◽  
Removal Of So2

The simultaneous removal of SO2 and NO was investigated with the activated carbon from sewage sludge (referred as ACS) modified by chitosan (referred as CS).The effects of CS loading and operating conditions on the simultaneous removal of SO2 and NO were analyzed. The results indicate that compared with the ACS, impregnating CS results in significant increase in SO2 or NO removal. Relative humidity enhances SO2 adsorption capacities, but not for NO. The SO2 adsorption capacities of the CS / ACS show no obvious decrease at small amount of NO in the feed. However, higher amounts of NO reduce the SO2 adsorption capacities. The opposite phenomenon appears for NO when a small amount of SO2. So a competitive sorption consists between NO and SO2. Simultaneous adsorptions for NO and SO2 is due to more active sites from CS.

Coupling ultrafiltration and adsorption onto activated carbon cloth: application to the treatment of highly coloured wastewaters

2000 ◽  
Vol 42 (5-6) ◽  
pp. 355-362 ◽  
Author(s):  
H. Pignon ◽  
C. Brasquet ◽  
P. Le Cloirec
Keyword(s):  
Molecular Weight ◽  
Activated Carbon ◽  
Adsorption Capacity ◽  
Membrane Filtration ◽  
Flow Reactor ◽  
Great Influence ◽  
Dye Adsorption ◽  
Operating Conditions ◽  
Carbon Cloth ◽  
Kinetics And Isotherms

The aim of this work is to evaluate the efficiency of Activated Carbon Cloths (ACCs) as a refining treatment of membrane filtration in the case of effluent streams containing both dyes and suspended solids (SS) or colloids responsible for turbidity. It is divided into two parts. First, dye adsorption experiments are carried out. Kinetics and isotherms enable us to show the feasibility of the adsorption and to study the influence of different operating conditions. The results demonstrate that adsorption is enhanced under acidic conditions, the adsorption capacity being increased by 40% in some cases. Moreover, microscopic characteristics of ACCs have a great influence on the adsorption process: there is a relationship between the adsorbent porosity and the adsorbate molecular weight, the mesoporous adsorbent being more efficious to remove the larger molecular weight dyes. In the case of low molecular weight compounds, the adsorbent with the higher specific surface area provides the greater adsorption capacity. Molecular connectivity indexes were used to confirm the correlation of the molecular structure of the adsorbates with their adsorbability. The second part consists of an estimation of the efficiency of the coupling of ultrafiltration and adsorption onto ACC. Tests performed on a laboratory-scale coupling show that a molecular weight cut-off of 3,000 D gives rise to a 98% removal of turbidity whereas dyes are not much retained. Furthermore, ultrafiltration is useful in improving the adsorption capacities of ACC in a continuous flow reactor (up to 50%).

Adsorption performance of powdered activated carbon-ultrafiltration systems

2001 ◽  
Vol 1 (5-6) ◽  
pp. 13-19 ◽  
Author(s):  
C. Campos ◽  
I. Baudin ◽  
J.M. Lainé
Keyword(s):  
Activated Carbon ◽  
Adsorption Process ◽  
Carbon Particle ◽  
Drinking Water Treatment ◽  
Powdered Activated Carbon ◽  
Operating Conditions ◽  
Adsorption Model ◽  
Filtration Time ◽  
Adsorption Removal ◽  
Carbon Performance

The use of powdered activated carbon in combination with ultrafiltration membranes is attracting increasing interest for the removal of organic compounds in drinking water treatment. The overall adsorption efficiency of this hybrid membrane process strongly depends on the reactor configuration and its operating conditions. Identification of the operating conditions yielding optimum carbon performance can be facilitated by the use of mathematical models describing the adsorption process. In this study, the effect of various designs and operating parameters on the efficiency of the adsorption process is discussed using an adsorption model previously developed and verified by the authors. This discussion includes the effect of filtration time, membrane reactor volume, carbon dosing procedure, carbon dose and carbon particle size on the adsorption removal of two selected micropollutants and dissolved organic matter.

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