Identification of an Appropriate Formulation for Domestic Water Ceramic Filters from Soukamna Clay (Cameroon)

This paper deals with the formulation of ceramic filters having the porosity adapted to domestic potable water treatment. The filters were made from clays and rice husk obtained from the Far North region of Cameroon (Logone Valley). Nine formulations were investigated to choose those that might have the porosity standing between 35 and 50% (the ideal porosity adapted for water treatment) [1]. The nine formulations investigated were as follow: clay:rice husk mixture weight ratio 0.7:0.3; 0.8:0.2 and 0.9:0.1 with the particle size of 100:100 microns. The sintering temperatures of 900°C, 950°C and 1000°C were applied for each of the mixtures. The results showed that only filters with weight ratio 0.7:0.3 sintered at 900°C, 950°C and 1000°C had porosity between 35 and 50% with values of 39.41±0.96; 40.15±1.59; 40.14±1.31 respectively. Mechanical strength, permeability and iron leaching behavior were investigated for these three formulations. The formulation 0.7:0.3 with sintering temperature of 1000°C had the higher permeability and was the more stable for iron leaching so it is the more adapted for water treatment in terms of flow rate and iron leaching behavior, pore size distribution showed that these filters were macroporous and designed for microfiltration with average pore diameter of 0.46µm.

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Hydrochloric Acid and/or Sodium Hydroxide-modified Zeolite Y for Catalytic Hydrotreating of α-Cellulose Bio-Oil

Indonesian Journal of Chemistry ◽

10.22146/ijc.55645 ◽

2020 ◽

Author(s):

Jason Mandela ◽

Wega Trisunaryanti ◽

Triyono Triyono ◽

Mamoru Koketsu ◽

Dyah Ayu Fatmawati

Keyword(s):

Pore Diameter ◽

Zeolite Y ◽

Weight Ratio ◽

Textural Properties ◽

Catalytic Performance ◽

Average Pore Diameter ◽

Average Pore ◽

Bio Oil ◽

Liquid Products ◽

Naoh Treatment

The zeolite Y had been successfully modified by HCl and/or NaOH treatment. The modification of zeolite Y was performed by leaching the protonated zeolite Y (HY) in HCl solution (0.1 and 0.5 M) at 70 °C for 3 h resulting in DY0.1 and DY0.5. Subsequently, HY, DY0.1, and DY0.5 zeolites were immersed in 0.1 M NaOH for 15 min at room temperature resulting in AHY, ADY0.1, and ADY0.5. All samples were analyzed for acidity, crystallinity, Si/Al ratio, morphology, and textural properties. The catalytic performance of all samples was investigated in hydrotreating of α-cellulose bio-oil with a catalyst/feed weight ratio of 1/30. The HCl and NaOH treatment led to the decrease of the zeolite Y crystallinity and the increase of the zeolite Y average pore diameter (i.e., the mesopore distribution). The ADY0.5 gave the highest mesopore distribution, which was 43.7%, with an average pore diameter of 4.59 nm. Moreover, both of the treatments were found to increase the Si/Al ratio that caused the decrease of zeolites Y acidity. All the zeolite Y samples gave better catalytic activity to produce liquid products after being treated by NaOH. The sample ADY0.5 managed to produce 6.12% of 1-isopropyl-2,4-dimethylbenzene that has good potential to be processed into fuel.

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Modification of Mordenite Characters by H2C2O4 and/or NaOH Treatments and Its Catalytic Activity Test in Hydrotreating of Pyrolyzed α-Cellulose

BULLETIN OF CHEMICAL REACTION ENGINEERING AND CATALYSIS ◽

10.9767/bcrec.16.1.9476.9-21 ◽

2021 ◽

Vol 16 (1) ◽

pp. 9-21

Author(s):

Triyono Triyono ◽

Wega Trisunaryanti ◽

Yessi Wydia Putri ◽

Dyah Ayu Fatmawati ◽

Uswatul Chasanah

Keyword(s):

Catalytic Activity ◽

Gas Flow ◽

Pore Diameter ◽

Liquid Product ◽

Weight Ratio ◽

Average Pore ◽

Activity Test ◽

Liquid Products ◽

Stainless Steel Reactor ◽

Open Access Article

The research about modification of mordenite characteristics has been performed by H2C2O4 and/or NaOH treatments and catalytic activity tests in hydrotreating of pyrolyzed a-cellulose. Commercial mordenite (HSZ-604OA) as mordenite control (HM) immersed in 0.05, 0.5, and 1.0 M H2C2O4 at 70 °C for three hours resulting in HM-0.05, HM-0.5, and HM-1. The four mordenites were immersed in 0.1 M NaOH for 15 minutes resulting in BHM, BHM-0.05, BHM-0.5, and BHM-1. The catalysts obtained were analyzed by XRD, SAA, ICP, and acidity test. The catalytic activity of the mordenites was evaluated in hydrotreating of pyrolyzed a-cellulose using stainless steel reactor with an H2 gas flow rate of 20 mL.min−1 at 450 °C for two hours with a catalyst: feed weight ratio of 1:60. The liquid products obtained from the hydrotreating were analyzed using GC-MS. The research results showed that the H2C2O4 and/or NaOH treatment towards the mordenites increased Si/Al ratio and decreased crystallinity. The acidity of mordenites decreased along with the increase of the Si/Al ratio. The average pore diameter of BHM, BHM-0.05, BHM-0.5, and BHM-1 mordenites were 2.898; 3.005; 3.792; 7.429 nm, respectively. The BHM-0.5 mordenite showed the highest catalytic activity in generating liquid product (88.88 wt%) and selectivity toward propanol (4.87 wt%). The BHM-1 mordenite showed catalytic activity in generating liquid product (41.16 wt%) and selectivity toward ethanol (1.21 wt%) and 2-heptyne (4.36 wt%). Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

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Determination of natural radionuclides in waste generated in the potable water treatment plants of the Zona da Mata of the state of Pernambuco- Brazil

Brazilian Journal of Radiation Sciences ◽

10.15392/bjrs.v7i2a.763 ◽

2019 ◽

Vol 7 (2A) ◽

Author(s):

Adriana Muniz De Almeida Albuquerque

Keyword(s):

Water Treatment ◽

Potable Water ◽

Natural Radionuclides ◽

The United States ◽

Radioactive Material ◽

Human Consumption ◽

Radiological Protection ◽

Natural Occurrence ◽

Water Treatment Plants ◽

Potable Water Treatment

The water purification procedure aims to obtain a product appropriate for human consumption, minimizing the presence of contaminants and toxic substances present in the water. Among these contaminants, some radionuclides of natural origin, such as uranium, thorium and their descendants, have been identified. Studies have shown that the stages of purification are quite effective in removing the radionuclides contained in water. The removal is due to co-precipitation of the radionuclides with the suspended materials and the precipitated material is accumulated and characterized as a Technologically Concentrated Natural Occurrence Radioactive Material (TENORM) by the United States Environmental Protection Agency (USEPA). This residue can present significant levels of radioactivity and, when discarded in the environment without any treatment, can generate a problem of environmental impact and a risk to the health of the population. In this way, some gamma emitters of the series of U, Th and the K-40 were determined in the residues generated at the Potable Water Treatment Plants – PWTPs in six municipalities of Pernambuco. The results obtain corroborate the classification of the residues generated in the PWTPs as concentrators of the radioactive components contained in the water supplied to the system and reinforce the need for the release to the environment, which is the usual way of disposal of this waste, to be carried out only after considering the radiological protection standards established.

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Fuels Desulphurisation by Adsorbtion on Fe / Bentonite

Revista de Chimie ◽

10.37358/rc.17.3.5483 ◽

2017 ◽

Vol 68 (3) ◽

pp. 483-486

Author(s):

Constantin Sorin Ion ◽

Mihaela Bombos ◽

Gabriel Vasilievici ◽

Dorin Bombos

Keyword(s):

Specific Surface ◽

Surface Area ◽

Specific Surface Area ◽

Pore Volume ◽

Pore Diameter ◽

Adsorption Process ◽

Continuous System ◽

Gas Oil ◽

Average Pore ◽

Atmospheric Distillation

Desulfurisation of atmospheric distillation gasoline and gas oil was performed by adsorption process on Fe/ bentonite. The adsorbent was characterized by determining the adsorption isotherms, specific surface area, pore volume and average pore diameter. Adsorption experiments of atmospheric distillation gasoline and gas oil were performed in continuous system at 280�320oC, 5 atm and volume hourly space velocities of 1�2 h-1. The efficiency of adsorption on Fe / bentonite was better at desulphurisation of gasoline versus gas oil.

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Preloading of GAC by natural organic matter in potable water treatment systems: Mechanisms, effects and design considerations

Journal of Water Supply Research and Technology—AQUA ◽

10.2166/aqua.2004.0037 ◽

2004 ◽

Vol 53 (7) ◽

pp. 469-482 ◽

Cited By ~ 5

Author(s):

Walter J. Weber

Keyword(s):

Organic Matter ◽

Water Treatment ◽

Natural Organic Matter ◽

Potable Water ◽

Design Considerations ◽

Potable Water Treatment

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Antibacterial silver-diatomite nanocomposite ceramic with low silver release

Water Science & Technology Water Supply ◽

10.2166/ws.2019.195 ◽

2019 ◽

Vol 20 (2) ◽

pp. 633-643

Author(s):

Xiaopeng Qi ◽

Junwei Chen ◽

Qian Li ◽

Hui Yang ◽

Honghui Jiang ◽

...

Keyword(s):

Electron Microscopy ◽

Water Treatment ◽

Photoelectron Spectroscopy ◽

Bactericidal Effect ◽

Ceramic Filter ◽

Ceramic Filters ◽

X Ray ◽

E Coli ◽

Point Of Use ◽

Silver Release

Abstract There is an urgent need for an effective and long-lasting ceramic filter for point-of-use water treatment. In this study, silver-diatomite nanocomposite ceramic filters were developed by an easy and effective method. The ceramic filters have a three-dimensional interconnected pore structure and porosity of 50.85%. Characterizations of the silver-diatomite nanocomposite ceramic filters were performed using scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. Silver nanoparticles were confirmed to be formed in situ in the ceramic filter. The highest silver concentration in water was 0.24 μg/L and 2.1 μg/L in short- and long-term experiments, indicating very low silver-release properties of silver-diatomite nanocomposite ceramic filter. The nanocomposite ceramics show strong bactericidal activity. When contact time with Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) of 105 colony forming units (CFU)/mL exceeded 3 h, the bactericidal rates of the four different silver content ceramics against E. coli and S. aureus were all 100%. Strong bactericidal effect against E. coli with initial concentration of 109 CFU/mL were also observed in ceramic newly obtained and ceramic immersed in water for 270 days, demonstrating its high stability. The silver-diatomite nanocomposite ceramic filters could be a promising candidate for point-of-use water treatment.

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Photocatalytic activity of Pr-modified TiO2 for the degradation of bisphenol A

SN Applied Sciences ◽

10.1007/s42452-021-04284-2 ◽

2021 ◽

Vol 3 (2) ◽

Author(s):

Denise S. Cordeiro ◽

Fernando L. Cassio ◽

Larissa Ciccotti ◽

Thiago L. R. Hewer ◽

Paola Corio ◽

...

Keyword(s):

Photocatalytic Activity ◽

Bisphenol A ◽

Pore Diameter ◽

Sol Gel ◽

Bandgap Energy ◽

Photocatalytic Efficiency ◽

Average Pore ◽

X Ray ◽

Vis Spectroscopy ◽

Adsorption Desorption

AbstractPraseodymium doped TiO2 nanoparticles were successfully prepared by the sol–gel method and characterized by X-ray powder diffraction, N2 adsorption–desorption isotherm, and UV–vis spectroscopy. The effects of the dopant on the crystallite size, specific surface area, average pore diameter, pore volume, and bandgap energy were investigated. The photocatalytic activity of the catalysts was evaluated by bisphenol A degradation and mineralization, which is a representative endocrine disruptor. Furthermore, under visible light irradiation the Pr-modified TiO2 photocatalysts exhibited higher photocatalytic efficiency than unmodified TiO2. When praseodymium was loaded (1.0–5.0%) onto the surface of TiO2, the rates of degradation and mineralization were increased 3–5 times.

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Diffusion of Heavy Oil in SiO2 Model Catalyst and FCC Catalyst

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.550-553.158 ◽

2012 ◽

Vol 550-553 ◽

pp. 158-163 ◽

Cited By ~ 2

Author(s):

Zi Yuan Liu ◽

Sheng Li Chen ◽

Peng Dong ◽

Xiu Jun Ge

Keyword(s):

Diffusion Coefficient ◽

Pore Size ◽

Effective Diffusion Coefficient ◽

Pore Diameter ◽

Effective Diffusion ◽

Model Catalyst ◽

Average Pore ◽

Diffusion Factor ◽

Fcc Catalyst ◽

Fcc Catalysts

Through the measured effective diffusion coefficients of Dagang vacuum residue supercritical fluid extraction and fractionation (SFEF) fractions in FCC catalysts and SiO2model catalysts, the relation between pore size of catalyst and effective diffusion coefficient was researched and the restricted diffusion factor was calculated. The restricted diffusion factor in FCC catalysts is less than 1 and it is 1~2 times larger in catalyst with polystyrene (PS) template than in conventional FCC catalyst without template, indicating that the diffusion of SFEF fractions in the two FCC catalysts is restricted by the pore. When the average molecular diameter is less than 1.8 nm, the diffusion of SFEF fractions in SiO2model catalyst which average pore diameter larger than 5.6 nm is unrestricted. The diffusion is restricted in the catalyst pores of less than 8 nm for SFEF fractions which diameter more than 1.8 nm. The tortuosity factor of SiO2model catalyst is obtained to be 2.87, within the range of empirical value. The effective diffusion coefficient of the SFEF fractions in SiO2model catalyst is two orders of magnitude larger than that in FCC catalyst with the same average pore diameter. This indicate that besides the ratio of molecular diameter to the pore diameter λ, the effective diffusion coefficient is also closely related to the pore structure of catalyst. Because SiO2model catalyst has uniform pore size, the diffusion coefficient can be precisely correlated with pore size of catalyst, so it is a good model material for catalyst internal diffusion investigation.

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Pore Structure and Mechanical Properties of ZrC/SiC Multi-Components Modified C/C Composites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.833.159 ◽

2013 ◽

Vol 833 ◽

pp. 159-164 ◽

Cited By ~ 1

Author(s):

Xiu Qian Li ◽

Hai Peng Qiu ◽

Jian Jiao

Keyword(s):

Mechanical Properties ◽

Pore Diameter ◽

Testing Machine ◽

Average Pore Diameter ◽

Flexural Properties ◽

Matrix Interface ◽

Polymeric Precursor ◽

Average Pore ◽

Fiber Matrix Interface ◽

Injection Apparatus

The ZrC/SiC multi-components modified C/C composites were prepared by using a hybrid precursor containning polycarbosilane and organic zirconium-contained polymeric precursor as impregnant and C/C composites of low density as preform. The porosity, microstructure and mechanical properties of samples were characterized with mercury injection apparatus, scanning electron microscopy and universal electron testing machine respectively. The results show that the porosity and average pore diameter decrease firstly and increase subsequently with the increase of organic zirconium content of the precursor. When the content of organic zirconium is 50%, the porosity and average pore diameter reach minimum which were7.27% and 0.0795um respectively. The most probabilistic pore diameter shifted from 10-100um to 1-10um at the same time; Meanwhile, the flexural properties also increases and drops immediately as the content of organic zirconium in the precursor adds. When the content of organic zirconium is 25%, the flexural strength reaches maximum of 245.20MPa.The improved flexural properties is attributed to the proper bonding of fiber-matrix interface and the low porosity of samples.

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