scholarly journals Low-Cost Goethite Nanorods for As (III) and Se (VI) Removal from Water

2020 ◽  
Vol 10 (20) ◽  
pp. 7237 ◽  
Author(s):  
Mokhtar Ali Amrani ◽  
Atef M. Ghaleb ◽  
Adham E. Ragab ◽  
Mohamed Z. Ramadan ◽  
Tamer M. Khalaf

Arsenite (As(III)) and Selenate (Se(VI)) are universally touted as extremely toxic oxyanions in natural and industrial water systems. Thus, the production of low-cost adsorbents that are scalable and toxic-free is of great importance today. In this work, a large-scale goethite nanorods (α-FeOOH NRs) is synthesized using a modified rapid hydrolysis method. The obtained powder is characterized using different multidisciplinary techniques. Accordingly, the results showed uniform and straight nanorods (length ~400 nm and diameter ~40 nm) resembling cigar-like morphology while the structure is confirmed to be of orthorhombic α-FeOOH phase. The potential application of this material to adsorb As (III) and Se (VI) ions in water is explored. In particular, for initial adsorbate concentrations (~500 µg/L), the removal efficiencies are found exceptional with α-FeOOH doses of 0.33 g/L and ~0.5 g/L for As (III) and Se (VI), respectively. Attractively, the adsorption capacities were estimated using trusted isotherms and then experimentally verified at ultimately high concentrations. Besides, a pH-controlled adsorption study showed that a pH of 5–8 is a favored range for higher ionic uptake, which meets the World Health Organization (WHO) benchmarks of drinking water. To conclude, the α-FeOOH NRs are potential adsorbent for the sustainable removal of toxin ions in water systems.

2020 ◽  
Vol 10 (10) ◽  
Author(s):  
Sandeep Police ◽  
Sukanta Maity ◽  
Dilip Kumar Chaudhary ◽  
Sanjay Kumar Sahu ◽  
A. Vinod Kumar

Abstract The groundwater samples were found to be contaminated with high concentrations of uranium (U) in Punjab state as well as in few other locations of India. U being chemically toxic can deteriorate health when ingested. Hence, there is a need to remove U from contaminated water using an efficient, cheap and user friendly method. A study was initiated to investigate the efficiency of low-cost adsorbents in removing U from water. Seven adsorbents were screened for U removal efficiency, among which fly ash (FA) and tea waste (TW) were found to have better removal efficiency. Solid–liquid contact time and solution pH were optimized to establish conditions for better U removal efficiency. The U adsorption on FA and TW followed pseudo-second-order kinetics with rate constant values 4.63 g/mg/min and 15.63 g/mg/min, respectively. FA and TW had the highest U removal capability at pH 6 and pH 4, respectively. The U sorption data were fitted with Freundlich and Dubinin–Radushkevich isotherm models. The U adsorption on FA and TW is found to be a physical process with mean free energy (E) values less than 8 kJ/mol. Theoretically calculated maximum adsorption capacity values indicate that FA is a better adsorbent as compared to TW, which has been further confirmed experimentally. The U adsorption on both the adsorbents has interference from Ca2+ and no interference from Fe3+ at tested U concentrations. It is also found that FA and TW are effective in decontaminating U from spiked real groundwater samples to below the WHO (Guidelines for drinking water quality, 4th ed, vol 1, World Health Organization, Geneva, 2011) limit.


2018 ◽  
Vol 90 (1) ◽  
pp. 63-77 ◽  
Author(s):  
Roxanne Brion-Roby ◽  
Jonathan Gagnon ◽  
Jean-Sébastien Deschênes ◽  
Bruno Chabot

AbstractArsenic is classified as one of the most toxic elements for humans by the World Health Organization (WHO). With the tightening drinking water regulation to 10 μg L−1 by the WHO, it is necessary to find efficient sorbent materials for arsenic. In this work, the removal of arsenic(V) from water is achieved with an insoluble chitosan sorbent in the protonated form obtained by a simple heating process. Kinetic studies show a very fast sorption (less than 10 min). The Langmuir isotherm model is best describing experimental data with a capacity of 42 mg g−1 at pH 8. The sorption process is based on anion exchange (chemisorption) determined from the Dubinin-Radushkevich model. The sorption efficiency of the chitosan sorbent is 97% at low concentrations (e.g. 100 μg L−1). Thermodynamic analysis reveals that the sorption process is exothermic and is controlled by enthalpic factors. Breakthrough curves (BTC) were acquired in real-time by instrumental chromatography and was better described by the Thomas model. BTC from column sorption and desorption with a salt solution suggest that this sorbent is relevant for large scale applications. With this new renewable product, it will be possible to treat arsenic contaminated water at low cost and with little waste (concentration factor of 1500).


2021 ◽  
Vol 11 (8) ◽  
pp. 3495
Author(s):  
Shabir Hussain ◽  
Yang Yu ◽  
Muhammad Ayoub ◽  
Akmal Khan ◽  
Rukhshanda Rehman ◽  
...  

The spread of COVID-19 has been taken on pandemic magnitudes and has already spread over 200 countries in a few months. In this time of emergency of COVID-19, especially when there is still a need to follow the precautions and developed vaccines are not available to all the developing countries in the first phase of vaccine distribution, the virus is spreading rapidly through direct and indirect contacts. The World Health Organization (WHO) provides the standard recommendations on preventing the spread of COVID-19 and the importance of face masks for protection from the virus. The excessive use of manual disinfection systems has also become a source of infection. That is why this research aims to design and develop a low-cost, rapid, scalable, and effective virus spread control and screening system to minimize the chances and risk of spread of COVID-19. We proposed an IoT-based Smart Screening and Disinfection Walkthrough Gate (SSDWG) for all public places entrance. The SSDWG is designed to do rapid screening, including temperature measuring using a contact-free sensor and storing the record of the suspected individual for further control and monitoring. Our proposed IoT-based screening system also implemented real-time deep learning models for face mask detection and classification. This module classified individuals who wear the face mask properly, improperly, and without a face mask using VGG-16, MobileNetV2, Inception v3, ResNet-50, and CNN using a transfer learning approach. We achieved the highest accuracy of 99.81% while using VGG-16 and the second highest accuracy of 99.6% using MobileNetV2 in the mask detection and classification module. We also implemented classification to classify the types of face masks worn by the individuals, either N-95 or surgical masks. We also compared the results of our proposed system with state-of-the-art methods, and we highly suggested that our system could be used to prevent the spread of local transmission and reduce the chances of human carriers of COVID-19.


2016 ◽  
Vol 36 (3) ◽  
pp. 239-243
Author(s):  
Grisel Marrero ◽  
Lilian P. Delgado ◽  
Humberto Caroll ◽  
Neise Ortiz ◽  
Alexis Musacchio ◽  
...  

Abstract A rapid, specific and sensible polystyrene latex-based reagent has been developed to detect rheumatoid factor (RF) in human sera. Detection of RF is one of the criteria for rheumatoid arthritis (RA) diagnosis. RF includes immunoglobulins IgG, IgM or IgA targeting human-IgG Fc region, found in sera of 70–90% of patients with RA. Spherical, clean polystyrene particles of 480±80 nm with a Z-potential of -28 mV were synthesized. Purified gamma-globulin human blood fraction, used as IgG source, was adsorbed on particles in glycine-buffered saline with a fivefold excess of the immunoglobulins needed to saturate the calculated total surface area of the particles. The reagent was calibrated against the World Health Organization international serum reference preparation and tested with commercial positive and negative RF controls. Reactivity of the developed diagnostic reagent with human sera, either positive or negative for RF, was evaluated. The sera were tested both intact and following complement inactivation. When complement-inactivated sera were used, our reagent showed 100% coincidence of results with a commercial diagnostic kit of specificity of 80% and sensibility of 93%. The in-house reagent developed in the present work is easy to prepare and at relatively low cost, making it ideal for RF detection in low-income settings.


Author(s):  
Vikas Sharma ◽  
Chandana Majee ◽  
Rahul Kaushik ◽  
Shivani Saxena ◽  
Salahuddin Salahuddin ◽  
...  

Herbal digestive tablets are meant for treating indigestion problems. The indigestion problem is one of the major problems of all (the) ages of human beings. As trends for eating fast foods is increasing, simultaneously the improper digestion also tends to increase. There are a number of digestive tablets in the market but in attempt to improve their taste the actual motto behind their use is masked. To combat the indigestion problems, in the present study an attempt has been made to formulate, develop and evaluate herbal digestive tablets. The formula of the digestive tablet has been decided after deep review of Ayurvedic formulary of India. The ingredients of this formulation have been procured from authentic sources. The wet granulation method was used to prepare the granules for punching the tablets. After preparation, the herbal digestive tablets were subjected to various pharmaceutical evaluations and quality control evaluations as per the guidelines from World Health Organization (WHO). The formulation was also subjected to antioxidant screening using Phosphomolybdenum method. The digestive tablets are obtained as light brown-colored round tablets with pleasant odour and spicy taste with an average size of 8mm and smooth edges. Maximum extractive value was observed as 34% in methanol with a total ash value of 10.16%. Other parameters reported as bitterness value- 0.69 units, volatile oil content-8%, loss on drying- 12.3%, swelling and foaming index of 0.27 and less than 100 respectively. The tablets showed a total antioxidant potential of 0.51mg/mg as Ascorbic acid equivalent. Tablets also pass various pharmaceutical evaluation parameters like hardness, friability, weight variation, and disintegration test. Herbal digestive tablets have very excellent taste due to less bitter drugs. The tablet formula can be applied to prepare large scale production of digestive tablets.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ole Lagatie ◽  
Ann Verheyen ◽  
Stijn Van Asten ◽  
Maurice R. Odiere ◽  
Yenny Djuardi ◽  
...  

Abstract Infections with intestinal worms, such as Ascaris lumbricoides, affect hundreds of millions of people in all tropical and subtropical regions of the world. Through large-scale deworming programs, World Health Organization aims to reduce moderate-to-heavy intensity infections below 1%. Current diagnosis and monitoring of these control programs are solely based on the detection of worm eggs in stool. Here we describe how metabolome analysis was used to identify the A. lumbricoides-specific urine biomarker 2-methyl pentanoyl carnitine (2-MPC). This biomarker was found to be 85.7% accurate in determining infection and 90.5% accurate in determining a moderate-to-heavy infection. Our results also demonstrate that there is a correlation between 2-MPC levels in urine and A. lumbricoides DNA detected in stool. Furthermore, the levels of 2-MPC in urine were shown to rapidly and strongly decrease upon administration of a standard treatment (single oral dose of 400 mg albendazole). In an Ascaris suum infection model in pigs, it was found that, although 2-MPC levels were much lower compared to humans, there was a significant association between urinary 2-MPC levels and both worm counts (p = 0.023) and the number of eggs per gram (epg) counts (p < 0.001). This report demonstrates that urinary 2-MPC can be considered an A. lumbricoides-specific biomarker that can be used to monitor infection intensity.


2018 ◽  
Vol 49 (3) ◽  
pp. 201-212
Author(s):  
Ana Carolina Amaya Arias ◽  
Óscar Zuluaga ◽  
Douglas Idárraga ◽  
Javier Hernando Eslava Schmalbach

Introduction: Most maternal deaths that occur in developing countries are considered unfair and can be avoided. In 2008, The World Health Organization (WHO) proposed a checklist for childbirth care, in order to assess whether a simple, low-cost intervention had an impact on maternal and neonatal mortality in low-income countries. Objective: To translate, adapt and validate the content of the WHO Safe Childbirth Checklist (SCC) for its use in Colombia Methods: The checklist was translated and adapted to the Colombian context. It was subsequently validated by a panel of experts composed of 17 health workers with experience in maternal and neonatal care and safety. Reliability among judges was estimated (Rwg) and items were modified or added to each section of the list according to the results. Results: Modifications were made to 28 items, while 19 new items were added, and none was removed. The most important modifications were made to the management guidelines included in each item, and the items added refer to risks inherent to our environment. Conclusion: The Colombian version of the SCC will be a useful tool to improve maternal and neonatal care and thereby contribute to reducing maternal and neonatal morbidity and mortality in our country.


2014 ◽  
Vol 5 (1) ◽  
pp. 28-38 ◽  
Author(s):  
L. Guerrero-Latorre ◽  
M. Rusiñol ◽  
A. Hundesa ◽  
M. Garcia-Valles ◽  
S. Martinez ◽  
...  

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.


2020 ◽  
Vol 12 (11) ◽  
pp. 206
Author(s):  
José Paulo Lousado ◽  
Sandra Antunes

The pandemic declared by the World Health Organization due to the SARS-CoV-2 virus (COVID-19) awakened us to a reality that most of us were previously unaware of—isolation, confinement and the massive use of information and communication technologies, as well as increased knowledge of the difficulties and limitations of their use. This article focuses on the rapid implementation of low-cost technologies, which allow us to answer a fundamental question: how can near real-time monitoring and follow-up of the elderly and their health conditions, as well as their homes, especially for those living in isolated and remote areas, be provided within their care and protect them from risky events? The system proposed here as a proof of concept uses low-cost devices for communication and data processing, supported by Long-Range (LoRa) technology and connection to The Things Network, incorporating various sensors, both personal and in the residence, allowing family members, neighbors and authorized entities, including security forces, to have access to the health condition of system users and the habitability of their homes, as well as their urgent needs, thus evidencing that it is possible, using low-cost systems, to implement sensor networks for monitoring the elderly using the LoRa gateway and other support infrastructures.


2020 ◽  
Vol 8 ◽  
Author(s):  
Lee Smith ◽  
Nicola Veronese ◽  
Vincenzo Racalbuto ◽  
Damiano Pizzol

The COVID-19 outbreak was declared by the World Health Organization (WHO) as global pandemic in March 2020. Considering the necessity to implement rapid response to control the pandemic and the fragility and the state of need of low income countries, it will be mandatory to develop a global approach in order to reduce the spread of infection and the creation of community viral reservoirs. So far, we could hypothesize a worst case scenario in which when the COVID-19 outbreak hits a peak in Africa and in low-income countries, the majority of such countries will be unprepared, with low resources allocated for affording the viral emergency and the consequences will be catastrophic with no lesson learnt. In the best case scenario, the COVID-19 will not affect Africa or South America on a large scale and, if the prevention measures will be implemented, we could register a lower incidence of hygiene linked diseases that still represent leading causes of death.


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