Point-of-entry adsorbers for the removal of fumigants

1995 ◽  
Vol 22 (1) ◽  
pp. 106-120
Author(s):  
Roberto M. Narbaitz ◽  
Frances Z. Parsons ◽  
Tsong-Yih Tzeng
Keyword(s):  
Organic Matter ◽  
Activated Carbon ◽  
Low Cost ◽  
Scale Up ◽  
Extensive Literature ◽  
Limited Data ◽  
Ethylene Dibromide ◽  
Point Of Entry ◽  
Naturally Occurring ◽  
Adsorption Data

Point-of-entry systems with granular activated carbon filters have been used extensively to provide safe water to rural homes with wells contaminated with synthetic organic chemicals. Because of the low cost of these systems, their design is generally based on the equilibrium column model, the isotherm data from the literature, and a scale-up factor. This paper analyzes the necessary scale-up factors for point-of-entry adsorbers based on fumigant adsorption data gathered through an extensive literature review. The fumigants evaluated are 1,2-dichloropropane, 1,2-dibromo-3-chloropropane, and ethylene dibromide. It was impossible to thoroughly assess the scale-up factors for 1,2-dichloropropane because of the limited data. Column data for the other two fumigants were sufficient to generate column loading lines, which can be used directly without resorting to scale-up factors. Column data showed that the scale-up factors are greatly affected by competitive adsorption with the naturally occurring background organic matter and by preloading of these organic matter. As these phenomena are not well understood, it is presently impossible to accurately predict the appropriate scale-up factors. A recommended design approach is outlined. Key words: adsorption, activated carbon, fumigants, point-of-entry.

scholarly journals Removal of Ni (II) from Aqueous Solution by Adsorption onto Activated Carbon Prepared from Lapsi (Choerospondias axillaris) Seed Stone

2014 ◽  
Vol 9 (1) ◽  
pp. 166-174 ◽  
Author(s):  
Rajeshwar M. Shrestha ◽  
Margit Varga ◽  
Imre Varga ◽  
Amar P. Yadav ◽  
Bhadra P. Pokharel ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Activated Carbons ◽  
Low Cost ◽  
Chemical Characterization ◽  
Maximum Adsorption Capacity ◽  
Adsorption Data ◽  
Optimum Ph ◽  
Nickel Adsorption

Activated carbons were prepared from Lapsi seed stone by the treatment with H2SO4 and HNO3 for the removal of Ni (II) ions from aqueous solution. Two activated carbon have been prepared from Lapsi seed stones by treating with conc.H2SO4 and a mixture of H2SO4 and HNO3 in the ratio of 1:1 by weight for removal of Ni(II) ions. Chemical characterization of the resultant activated carbons was studied by Fourier Transform Infrared Spectroscopy and Boehm titration which revealed the presence of oxygen containing surface functional groups like carboxyl, lactones and phenols in the carbons. The optimum pH for nickel adsorption is found to be 5. The adsorption data were better fitted with the Langmuir equations than Freundlich adsorption equation to describe the equilibrium isotherms. The maximum adsorption capacity of Ni (II) on the resultant activated carbons was 28.25.8 mg g-1 with H2SO4 and 69.49 mg g-1 with a mixture of H2SO4 and HNO3. The waste material used in the preparation of the activated carbons is inexpensive and readily available. Hence the carbons prepared from Lapsi seed stones can act as potential low cost adsorbents for the removal of Ni (II) from water. DOI: http://dx.doi.org/10.3126/jie.v9i1.10680Journal of the Institute of Engineering, Vol. 9, No. 1, pp. 166–174

Geosmin and 2-methylisoborneol adsorption on super-powdered activated carbon in the presence of natural organic matter

2010 ◽  
Vol 62 (11) ◽  
pp. 2664-2668 ◽  
Author(s):  
Y. Matsui ◽  
Y. Nakano ◽  
H. Hiroshi ◽  
N. Ando ◽  
T. Matsushita ◽  
...  
Keyword(s):  
Organic Matter ◽  
Activated Carbon ◽  
Surface Water ◽  
Natural Organic Matter ◽  
Powdered Activated Carbon ◽  
Severe Problem ◽  
Naturally Occurring ◽  
Adsorption Capacities ◽  
Low Efficiency ◽  
Utilities Services

Geosmin and 2-methylisoborneol (2-MIB) are naturally occurring compounds responsible for musty-earthy-odors in surface water supplies. They are a severe problem confronting utilities worldwide. Adsorption by powdered activated carbon (PAC) is a widely used process to control this problem, but it has low efficiency, which engenders large budget spending for utilities services. Super-powdered activated carbon (S-PAC) is activated carbon with much finer particles than those of PAC. Experiments on geosmin and 2-MIB adsorptions on S-PAC and PAC were conducted. Geosmin and 2-MIB adsorption capacities on S-PAC were not smaller than those on PAC although natural organic matter, which adversely impacted the adsorption capacity of geosmin and 2-MIB, was more adsorbed on S-PAC than on PAC, meaning that the adsorption competition is less severe for S-PAC than for PAC.

scholarly journals Adsorptive removal of methyl orange and methylene blue from aqueous solutions with Acacia crassicarpa activated carbon

2021 ◽  
Vol 63 (4) ◽  
pp. 23-27
Author(s):  
Tue Ngoc Nguyen ◽  
◽  
Khanh Quoc Dang ◽  
Duc Trung Nguyen ◽  
◽  
...  
Keyword(s):  
Methylene Blue ◽  
Activated Carbon ◽  
Methyl Orange ◽  
Aqueous Solutions ◽  
Langmuir Isotherm ◽  
Low Cost ◽  
Scale Up ◽  
Anionic Dyes ◽  
Experimental Conditions ◽  
Acacia Crassicarpa

In this study, activated carbon prepared from Acacia crassicarpa barkwas prepared and studied for the potential development of low-cost, carbon-based adsorbents that remove industrial dyes from aqueous solutions. Various spectroscopy techniques and surface analyses were used to characterize the adsorbents. The adsorption of methyl orange (MO) and methylene blue (MB) onto the material was investigated under optimal experimental conditions including temperature, adsorbent dosage, and initial concentration of chemicals. The Langmuir isotherm model was observed to fit the adsorption data well. The maximum adsorption capacities predicted by the Langmuir isotherm were found to be 10.36 mg.g-1 for MO and 15.34 mg.g-1 for MB. The adsorbents were better able to remove the cationic dye than the anionic dye. The results of this study will be useful for future scale-up production of low-cost adsorbents using Acacia crassicarpa for the removal of cationic and anionic dyes.

scholarly journals Efficiency of Sawdust as Low-Cost Adsorbent for Dyes Removal

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
R. Chikri ◽  
N. Elhadiri ◽  
M. Benchanaa ◽  
Y. El maguana
Keyword(s):  
Activated Carbon ◽  
Activated Carbons ◽  
Low Cost ◽  
Base Material ◽  
Isotherm Models ◽  
Extensive Literature ◽  
Effective Technique ◽  
Adsorption Isotherm Models ◽  
Harmful Effects ◽  
Dyes Removal

In recent years, the removal of dyes from wastewater has attracted considerable attention due to their harmful effects to ecosystem and human health. Adsorption as a facile and effective technique has been widely used to eliminate a large variety of dyes from aqueous solutions. Activated carbon is the most preferred adsorbent to treat wastewater but its use is limited because of high cost. Therefore, several low-cost and natural materials and wastes have been used as precursors for the preparation of alternative adsorbents. Among them, sawdust as an abundant and low-cost by-product has been explored as adsorbent for the removal of dyes from wastewater. This review focuses on the various sawdust used as a precursor for the preparation of activated carbons. Extensive literature information about sawdust, its compositions, activation methods, its efficiency for dyes removal, and environmental conditions effects has been reviewed. The applicability of various adsorption kinetic models and adsorption isotherm models for dye removal by sawdust-derived activated carbons has been also reported. Finally, this paper highlights the use of sawdust as base material for various composites and mixture which can be used as granular activated carbon.

scholarly journals A water-activated battery based on activated carbon

2019 ◽  
Vol 9 (5) ◽  
pp. 4053
Author(s):  
Dang Trang Nguyen ◽  
Kozo Taguchi
Keyword(s):  
Activated Carbon ◽  
Proton Exchange Membrane ◽  
Low Cost ◽  
Scale Up ◽  
Proton Exchange ◽  
Carbon Paper ◽  
Carbon Powder ◽  
Multiwalled Carbon ◽  
Powder Concentration ◽  
Micropower Generation

In this research, a novel property of activated carbon powder (AC powder) has been utilized to realize a disposable paper-based battery. AC powder was loaded on a 3D carbon paper substrate to make the anode. The cathode was integrated directly on the paper-based battery case by coating multiwalled carbon nanotube mixed with potassium ferricyanide on a side of a sheet of filter paper, the other side worked as a paper-based proton exchange membrane. This design provides a simple but practical disposable water-activated battery. The developed battery generated the maximum power density of 10.4 µW/cm2 at the AC powder concentration of 17 mg/cm2. Although, the output power of the battery is low, it is made of low-cost and abundant materials, and therefore being able to scale up. The battery is a disposable and on-demand micropower generation activated anytime, anywhere by water.

Constructive Optimisation of the Propeller Type Mixing Devices Using the Virtual and Rapid Prototyping

2017 ◽  
Vol 68 (3) ◽  
pp. 453-458 ◽  
Author(s):  
Daniel Besnea ◽  
Alina Spanu ◽  
Iuliana Marlena Prodea ◽  
Gheorghita Tomescu ◽  
Iolanda Constanta Panait
Keyword(s):  
Rapid Prototyping ◽  
Low Cost ◽  
Scale Up ◽  
Three Dimensional ◽  
Rapid Identification ◽  
Multidisciplinary Optimization ◽  
External Diameter ◽  
Process Industries ◽  
Parametric Cad ◽  
Shaft Torque

The paper points out the advantages of rapid prototyping for improving the performances/constructive optimization of mixing devices used in process industries, here exemplified to propeller types ones. The multidisciplinary optimization of the propeller profile affords its design using parametric CAD methods. Starting from the mathematical curve equations proposed for the blade profile, it was determined its three-dimensional virtual model. The challenge has been focused on the variation of propeller pitch and external diameter. Three dimensional ranges were manufactured using the additive manufacturing process with Marker Boot 3D printer. The mixing performances were tested on the mixing equipment measuring the minimum rotational speed and the correspondent shaft torque for complete suspension achieved for each of the three models. The virtual and rapid prototyping method is newly proposed by the authors to obtain the basic data for scale up of the mixing systems, in the case of flexible production (of low quantities), in which both the nature and concentration of the constituents in the final product varies often. It is an efficient and low cost method for the rapid identification of the optimal mixing device configuration, which contributes to the costs reduction and to the growing of the output.

scholarly journals Na0.76V6O15/Activated Carbon Hybrid Cathode for High-Performance Lithium-Ion Capacitors

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 122
Author(s):  
Renwei Lu ◽  
Xiaolong Ren ◽  
Chong Wang ◽  
Changzhen Zhan ◽  
Ding Nan ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Energy Density ◽  
Power Density ◽  
Cathode Materials ◽  
Low Cost ◽  
Lithium Ion ◽  
High Energy ◽  
Cycling Stability ◽  
High Energy Density ◽  
Artificial Graphite

Lithium-ion hybrid capacitors (LICs) are regarded as one of the most promising next generation energy storage devices. Commercial activated carbon materials with low cost and excellent cycling stability are widely used as cathode materials for LICs, however, their low energy density remains a significant challenge for the practical applications of LICs. Herein, Na0.76V6O15 nanobelts (NaVO) were prepared and combined with commercial activated carbon YP50D to form hybrid cathode materials. Credit to the synergism of its capacitive effect and diffusion-controlled faradaic effect, NaVO/C hybrid cathode displays both superior cyclability and enhanced capacity. LICs were assembled with the as-prepared NaVO/C hybrid cathode and artificial graphite anode which was pre-lithiated. Furthermore, 10-NaVO/C//AG LIC delivers a high energy density of 118.9 Wh kg−1 at a power density of 220.6 W kg−1 and retains 43.7 Wh kg−1 even at a high power density of 21,793.0 W kg−1. The LIC can also maintain long-term cycling stability with capacitance retention of approximately 70% after 5000 cycles at 1 A g−1. Accordingly, hybrid cathodes composed of commercial activated carbon and a small amount of high energy battery-type materials are expected to be a candidate for low-cost advanced LICs with both high energy density and power density.

scholarly journals Mendelian randomisation for psychiatry: how does it work, and what can it tell us?

2021 ◽  
Author(s):  
Robyn E. Wootton ◽  
Hannah J. Jones ◽  
Hannah M. Sallis
Keyword(s):  
Risk Factors ◽  
Mental Illness ◽  
Risk Factor ◽  
Low Cost ◽  
Sensitivity Analyses ◽  
Mendelian Randomisation ◽  
Naturally Occurring ◽  
Complementary Approach ◽  
Randomised Control Trials ◽  
Successful Prevention

AbstractThe successful prevention of mental illness relies upon the identification of causal, modifiable risk factors. However, observational evidence exploring such risk factors often produces contradictory results and randomised control trials are often expensive, time-consuming or unethical to conduct. Mendelian randomisation (MR) is a complementary approach that uses naturally occurring genetic variation to identify possible causal effects between a risk factor and an outcome in a time-efficient and low-cost manner. MR utilises genetic variants as instrumental variables for the risk factor of interest. MR studies are becoming more frequent in the field of psychiatry, warranting a reflection upon both the possibilities and the pitfalls. In this Perspective, we consider several limitations of the MR method that are of particular relevance to psychiatry. We also present new MR methods that have exciting applications to questions of mental illness. While we believe that MR can make an important contribution to the field of psychiatry, we also wish to emphasise the importance of clear causal questions, thorough sensitivity analyses, and triangulation with other forms of evidence.

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