Plasticity characterization of certain Nigeria clay minerals for their application in ceramic water filters

Plasticity is an essential property of clay that determines its suitability for water filtration. There are no published works on the plastic behavior of clays from the study locations. The plastic behavior of seven Nigerian clays was examined using plasticity indices and compressive stress parameters in relation to chemical compositions and moisture content. The objective is to determine plastic behavior of some Nigerian clays and their suitability in production of Expanded Clay Aggregates (ECA) for water filters. Compressive stresses and deformation parameters were determined experimentally and compared theoretically. Atterberg limits (D 4318) were used to determine the plasticity indices. Chemical compositions of the samples were examined with XRF and correlated with plasticity and mineral contents of the clays. The clays are aluminosilicates with SiO2/Al2O3 ratio of 1.61 to 3.03 and plastic indices of 8 to 49. Low plastic indices (8–11) and low compressive stresses parameters were observed for kaolinite clays (0.002 MPa) due to their low affinity for water while zeolite rich clays showed high plastic indices (46 and 49) for Obowo and Minna and sharp difference in their compressive stresses parameters (0.15 and 0.03 MPa) at optimum moisture contents of 57% and 53%, respectively. Despite varying moisture content, chemical and mineral compositions, all curves showed similar trends apart from kaolinites at 40% moisture content. Relationships exist among microstructural properties, chemical composition, moisture content, compressive strength, and plasticity indices of the clays. The plastic behaviors show they are suitable for development of ECA for water filters.

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Ceramic Water Filters as a Response Technology to Geo-Hazards

The Global Environmental Engineers ◽

10.15377/2410-3624.2018.05.1 ◽

2018 ◽

Vol 5 (1) ◽

pp. 1-8

Author(s):

E. McBean ◽

◽

G. Huang ◽

Yongping Li ◽

Yanfeng Li ◽

...

Keyword(s):

Ceramic Water Filters ◽

Water Filters

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Combined effect of mineralogical and chemical parameters on swelling behaviour of expansive soils

Scientific Reports ◽

10.1038/s41598-021-95746-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Bendadi Hanumantha Rao ◽

Peddireddy Sreekanth Reddy ◽

Bijayananda Mohanty ◽

Krishna R. Reddy

Keyword(s):

Expansive Soils ◽

Research Work ◽

Swelling Pressure ◽

Combined Effect ◽

Practical Significance ◽

Chemical Compositions ◽

Chemical Parameters ◽

Swelling Behaviour ◽

Mineral Contents ◽

Swelling Properties

AbstractMicrolevel properties such as mineralogical and chemical compositions greatly control the macro behaviour of expansive soils. In this paper, the combined effect of mineral (i.e. montmorillonite, MMC) and chemical contents (i.e. Ca and Na in their total (T), leachable (L) and exchangeable form (CEC)) on swelling behaviour is investigated in a comprehensive way. Several 3-dimensional (3D) graphs correlating MMC and Ca/Na ratio, together, with swelling property (swelling potential, Sa, and swelling pressure, Sp) are developed. 3D plots, in general, portrayed a non-linear relationship of Sa and Sp with MMC and Ca/Na ratio, together. It is hypothesized that swelling initially is triggered by chemical parameters due to their quick and rapid ionization capability, but the overall swelling phenomenon is largely controlled by MMC. It is importantly found that expansive soils are dominant with divalent Ca++ ions up to MMC of 67% and beyond this percentage, monovalent Na+ ions are prevalent. From the interpretation of results, the maximum Sa of 18% and Sp of 93 kPa is measured at MMC of 43%, (Ca/Na)T of 10–14 and (Ca/Na)L of 2–7. It is concluded from study that total CEC + MMC for determining Sa and (Ca/Na)T + MMC for determining Sp are superior parameters to be considered. The findings of the study also excellently endorsed the results of Foster32, who stated that ionization of Na or Ca depends on the constituent mineral contents. The findings presented herein are unique, interesting and bear very practical significance, as no earlier research work reported such findings by accounting for chemical and mineralogical parameters impact, in tandem, on swelling properties.

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Virus removal efficiency of ceramic water filters: effects of bentonite turbidity

Water Science & Technology Water Supply ◽

10.2166/ws.2013.206 ◽

2013 ◽

Vol 14 (2) ◽

pp. 304-311 ◽

Cited By ~ 2

Author(s):

Cameron Farrow ◽

Edward McBean ◽

Hamidreza Salsali

Keyword(s):

Removal Efficiency ◽

Potable Water ◽

Source Water ◽

Virus Removal ◽

Ceramic Water Filters ◽

Point Of Use ◽

Cake Layer ◽

Human Enteric Viruses ◽

Removal Efficiencies ◽

Water Filters

Ceramic water filters (CWFs) are utilized in many developing countries as point-of-use (POU) water treatment devices, to reduce waterborne pathogens in potable water. Virus removal efficiencies of several CWFs are investigated under various influent conditions using MS2 (ATCC: 15597-B1) as a surrogate phage for human enteric viruses. The addition of bentonite turbidity (6–8 NTU) in the influent source water showed increased viral removal efficiency of CWFs by 0.1–0.2 log compared to tests involving clear (<1 NTU) influents. Trials employing an applied clay cake layer, formed using highly turbid influent source water (100 NTU) and no cleaning regime between trials, resulted in viral removal efficiency values of 1.5–2.5 log, compared to 0.2–0.5 log during non-obstructed trials.

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A comprehensive review of algal biochar for soil improvement: bottlenecks and opportunities

10.5194/egusphere-egu21-3558 ◽

2021 ◽

Author(s):

Jiacheng Sun ◽

Ondrej Masek

Keyword(s):

Climate Change ◽

Environmental Sustainability ◽

Carbon Capture And Storage ◽

Soil Improvement ◽

Chemical Oxidation ◽

Chemical Compositions ◽

Mineral Contents ◽

Comprehensive Review ◽

Positive Effects ◽

Algal Biochar

In recent years, the rapid increase of CO2 emission in the atmosphere and the resulting issues such as global warming and climate change have now become significant barriers to environmental sustainability. Although fossil CO2 emissions have decreased in some of the world's largest emitters, including 11% in the EU, 12% in the US and 1.7% in China annually, the estimated global CO2 emission amount still reached 40 G tonnes in 2020. The purpose of studying biochar produced by pyrolysis is essential to develop the knowledge of carbon cycles and nutrient components in soil. Among all types of feedstocks, algae grow incredibly rapidly compared to other biological materials, about 500-1500 times higher, which will boot the carbon sequestration rate. Therefore, the study of algal biochar production through pyrolysis has great significance for migrating climate change and developing carbon capture and storage.This study focuses on a comprehensive review of previous literature on conventional and advanced macroalgae and microalgae pyrolysis for producing biochar and related valuable by-products like bio-oil and bio-syngas, aiming to establish a state-of-the-art of algal biochar for different soil-related applications and demonstrate the bottlenecks and opportunities. Specifically, a thorough comparison of algae species (20 microalgae and 20 macroalgae) is developed to benefit future researchers, involving chemical compositions, proximate analysis, solid-product fraction, physical properties and chemical properties. Redox conditions, surface functional groups and pH conditions are determined in lab-scale. Moreover, different algal biochar applications on soil and plant are analysed to optimise the commercial value of algal biochar, including soil conditioner, compositing additives, carrier for fertilisers, manure treatment and stable blending. Due to the abundant mineral contents (0.23-1.21% Na, 0.03-2.92% K, 0.75-7.17% Al, 0.19-1.24% Mg, 6.5-7% Ca and 0.04-0.69% Fe) of algal biochar, this study not only reviews the positive effects on soil improvement but also negative effects such as phytotoxic effect and heavy-metal pollution. A laboratory-based chemical oxidation approach (Edinburgh Stability Tool) is used to assess relatively long-term biochar stability and the influence of nutrient cycling. The optimal pyrolysis conditions (temperature, retention time and heating rate) and potential future commercial applications are obtained through the comprehensive review of algal biochar for soil improvement.&#160;&#160;&#160;&#160;

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Simplified FEA Models in the Analysis of the Redistribution of Beneficial Compressive Stresses in Welds During Cyclic Loading

Volume 11B: Honoring Symposium for Professor Carlos Guedes Soares on Marine Technology and Ocean Engineering ◽

10.1115/omae2018-77401 ◽

2018 ◽

Author(s):

B. L. Josefson ◽

J. Alm ◽

J. M. J. McDill

Keyword(s):

Cyclic Loading ◽

Residual Stresses ◽

Compressive Stress ◽

Welding Process ◽

Plastic Behavior ◽

Element Analysis ◽

Compressive Stresses ◽

Static Contact ◽

Weld Toe ◽

Compressive Residual Stresses

The fatigue life of welded joints can be improved by modifying the weld toe geometry or by inducing beneficial compressive residual stresses in the weld. However, in the second case, the induced compressive residual stresses may relax when the welded joint is subjected to cyclic loading containing high tensile or compressive stress peaks. The stability of induced compressive stresses is investigated for a longitudinal gusset made of a S355 steel. Two methods are considered; either carrying out a high frequency mechanical impact (HFMI) treatment after welding or alternatively using low transformation temperature (LTT) electrodes during welding. The specimen is then subjected to a cyclic loading case with one cycle with a tensile peak (with magnitude reaching the local yield stress level) followed by cycles with constant amplitude. A sequential finite element analysis (FEA) is performed thereby preserving the history of the elasto-plastic behavior. Both the welding process and the HFMI treatment are simulated using simplified approaches, i.e., the welding process is simulated by applying a simplified thermal cycle while the HFMI treatment is simulated by a quasi-static contact analysis. It is shown that using the simplified approaches to modelling both the welding process and HFMI treatment gives results that correlate qualitatively well with the experimental and FEA data available in the literature. Thus, for comparison purposes, simplified models may be sufficient. Both the use of the HFMI treatment and LTT electrodes give approximately the same compressive stress at the weld toe but the extent of the compressive stress zone is deeper for HFMI case. During cyclic loading it is shown that the beneficial effect of both methods will be substantially reduced if the test specimen is subjected to unexpected peak loads. For the chosen load sequence, with the same maximum local stress at the weld toe, the differences in stress curves of the HFMI-treated specimen and that with LTT electrodes remain. While the LTT electrode gives the lowest (compressive) stress right at the well toe, it is shown that the overall effect of the HFMI treatment is more beneficial.

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Performance of black ceramic water filters and their implementation in rural Ecuador

Journal of Water Sanitation and Hygiene for Development ◽

10.2166/washdev.2019.185 ◽

2019 ◽

Vol 9 (4) ◽

pp. 694-702 ◽

Cited By ~ 1

Author(s):

Laura Guerrero-Latorre ◽

Priscila Balseca-Enriquez ◽

Carlos Moyota-Tello ◽

Ronald Bravo-Camino ◽

Stephanie Davila-Chavez ◽

...

Keyword(s):

Water Quality ◽

Water Treatment ◽

New Technology ◽

Classical Model ◽

International Standards ◽

Household Water Treatment ◽

Household Level ◽

Ceramic Water Filters ◽

Field Level ◽

Water Filters

Abstract In rural Ecuador, microbial water contamination is associated with child morbidity mainly due to gastroenteritis. Black ceramic water filters (BCWF) are a new household water treatment recently developed to improve microbial removal from the classical model implemented worldwide. This study has assessed BCWF microbial performance at laboratory level by continuous filtering of spiked water with microbial surrogates (Escherichia coli and MS2 bacteriophage) and highly contaminated surface water to evaluate physicochemical pollutants' removal. At field level, baseline studies in Nanegal and Gualea districts have been performed to evaluate water quality and hygiene practices among communities and a six-month BCWF field implementation study in the Santa Marianita community. Results revealed poor drinking water quality in communities studied. Water treatment practices at household level were reported in low percentages. Conversely, results in BCWF filter assays at laboratory level for 600 litres of usage have shown 5.36 logarithms of bacterial removal and 3.83 logarithms for viral removal and significant reductions of physicochemical pollutants considering international standards. BCWF implementation in the Santa Marianita community reveals promising results on microbial water quality in households using this new technology. However, it is important to reinforce correct BCWF maintenance for better performance at field level.

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Nutritional qualities assessment of locally processed spaghetti

International Journal of Scientific World ◽

10.14419/ijsw.v5i1.6900 ◽

2016 ◽

Vol 5 (1) ◽

pp. 5

Author(s):

Bitrus Tukura ◽

Joseph Daniel Gbubele ◽

Swaiba Mamman

Keyword(s):

Moisture Content ◽

Crude Protein ◽

Zinc Content ◽

Mineral Elements ◽

Crude Fiber ◽

Nutritional Properties ◽

Mineral Contents ◽

Standard Methods ◽

Nutritional Qualities ◽

Low Levels

The quest for cheap and quality food is on the increase, especially during economy crises. Some nutritional properties of the raw and cooked local and industrial spaghetti were determined using standard methods. Concentrations of mineral elements were determined using atomic absorption spectrophotometer. Total ash (0.98±007 %), crude protein (14.28±0.15 %) and carbohydrate (77.95±0.11 %) levels in the raw industrial spaghetti were higher compared to the locally processed raw spaghetti. Carbohydrate and moisture levels for both processed spaghetti increased on cooking, while total ash and protein contents decreased. Crude fiber (0.009±0.00 %), carbohydrate (77.52±0.21 %) and moisture levels in the cooked local spaghetti were higher than in the cooked industrial spaghetti. Proximate contents of the local and industrial raw spaghetti were significantly (P ≤ 0.05) different. Concentrations of mineral elements in the raw locally processed spaghetti were lower than in the industrial spaghetti. Low levels of functional properties were recorded in the local spaghetti. Cooking decreased zinc content in the spaghetti, but significantly (P ≤ 0.05) increased the moisture content, crude fiber, carbohydrate and mineral contents. The spaghetti processed locally may serve as an alternative to the industrial spaghetti.

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Development of improved low-cost ceramic water filters for viral removal in the Haitian context

Journal of Water Sanitation and Hygiene for Development ◽

10.2166/washdev.2014.121 ◽

2014 ◽

Vol 5 (1) ◽

pp. 28-38 ◽

Cited By ~ 4

Author(s):

L. Guerrero-Latorre ◽

M. Rusiñol ◽

A. Hundesa ◽

M. Garcia-Valles ◽

S. Martinez ◽

...

Keyword(s):

Low Income ◽

Low Cost ◽

World Health ◽

Low Income Countries ◽

Virus Removal ◽

Ceramic Water Filters ◽

Removal Efficiencies ◽

Reductive Atmosphere ◽

Health Organization ◽

Water Filters

Household-based water treatment (HWT) is increasingly being promoted to improve water quality and, therefore, health status in low-income countries. Ceramic water filters (CWFs) are used in many regions as sustainable HWT and have been proven to meet World Health Organization (WHO) microbiological performance targets for bacterial removal (2–4 log); however, the described viral removal efficiencies are insufficient to significantly reduce the associated risk of viral infection. With the objective of improving the viral removal efficiencies of ceramic water filters, new prototypes with different oxide compositions and firing atmospheres have been developed and evaluated. For removal efficiencies human adenoviruses, MS2 bacteriophage and Escherichia coli were quantified in all prototypes. A new model of CWF that was fired in a reductive atmosphere presented virus and bacteria removal efficiencies greater than 3.0 log and 2.5 log, respectively, which would fulfill the viral targets that are recommended by the WHO. Ceramic characterization of the selected filters, which were fired in a reductive atmosphere, showed that a larger specific surface area than those of control filters and higher fraction of a positive Z-potential fraction are the most likely explanations for this increase in virus removal.

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