scholarly journals Development and applications of novel nanostructured materials in water treatment : adsorption, filtration, and reaction

2021 ◽  
Author(s):  
◽  
Mohammed M. Numaan

Nanomaterial-based adsorbents and photocatalysts have gained increasing attention in the applications of water and wastewaters treatment due to their attractive properties and strong adsorption capabilities for a wide range of contaminants. The objective of this study is to fabricate, characterize, and apply a group of nanomaterials to adsorb, remove, and degrade contaminants in water. An iron oxide/graphene oxide (IOGOx) composite was evaluated for the effective As(V) removal from the aqueous solutions. Adsorption on hematite and IOGO(25 [percent]) at 25 [degrees]C, pH 7, and 1 mM NaNO3 showed 76 [percent] of As(V) removal within the first 5 minutes and 95 [percent] at 40 minutes. As(V) adsorption efficiency increased with increase GO loading; while, this efficiency decreased at high IO loading. Kinetic data was a well fitted to pseudo-second-order, so those results suggested that the surface complexation is the main mechanism for As(V) adsorption on the surface of adsorbents. All composites were able to reduce the As(V) concentration below 10 [micro]gL[superscript -1] that is the recommended maximum permissible concentration of As(V) in drinking water by World Health Organization (WHO). A novel technique for coating a group of tubular ceramic membranes by multi-layers of TiO2 was used to reduce the pore size of the support membranes and to improve their performances. Polyethylene glycol was used as a model molecule to compare and examine the coated membranes in the evolution of fouling and rejection over time. The SEM images showed that TiO2 covered the surface and the active layer; therefore, the permeable path sizes decreased gradually. The results of flux and permeability of membranes confirmed the success of the coating. The transmembrane pressure (TMP) increased with each coating layer, while the rejection of the membrane was improved. After cleaning the membranes with ultrapure water, TMP of all the membranes decreased until reaching to the clean material values. In this study, 4-layers coated membrane showed its ability to be used many times after cleaning with ultrapure water. The coated membranes were tested for a novel technique that combines filtration and advanced oxidation processes for sulfamethazine (SMZ) removal and degradation using a continues flow reactor and under different conditions. The system included a a membrane module with UV-light. In the absence of UV-light, the results showed no significant removal of 5 ppm and 10 ppm of SMZ during the experiment. Under UV-light, the system was able to significantly degrade 5 ppm and 10 ppm of SMZ from the solution, particularly, at pH 2. In the presence of humic acid (HA), there was a significant increase in the SMZ degradation with all pH values by decreasing the required time to degrade SMZ in clean water. When NO3[superscript -] or Cl[superscript -] ions were added, an increase in the degradation rate of SMZ was observed in the presence of NO3[superscript -] in comparison with clean water, but Cl[superscript -] led to a decrease in the SMZ degradation under UV light. The process could be applied for SMZ removal from the water in water treatment plants.

2018 ◽  
Vol 6 (3) ◽  
Author(s):  
Arie Herlambang

Clean water to poor communities who live in crowded municipal area is stillexpensive and a luxury. This condition is evidenced by the number of people whouse ground water for their daily water, because water taps still seems expensivefor them. Diarrheal disease is still relatively high for Indonesia, where nearly 16thousand people suffer from diarrhea due to poor sanitation. To help the poor inthe city, there are several alternative technologies that can be applied to publicaccess to clean water and adequate low-cost, including ground water treatmenttechnology with a filter system equipped with an ultraviolet sterilizer, or ozonegenerators, or using ultrafiltration, if possible can also use the reverse osmosismembrane that for fresh water. Arsinum is the best alternative should be chosenfor fulfilled potable water in slump area.Keywords : Sanitation, water treatment technology, portable water, low-cost, slump area


2019 ◽  
Vol 70 (7) ◽  
pp. 2330-2334
Author(s):  
Mihaela Ciopec ◽  
Adina Negrea ◽  
Narcis Duteanu ◽  
Corneliu Mircea Davidescu ◽  
Iosif Hulka ◽  
...  

Arsenic content in groundwater�s present a wide range of concentration, ranging from hundreds of micrograms to thousands of micrograms of arsenic per litter, while the maximum permitted arsenic concentration established by World Health Organization (WHO) is 10 mg L-1. According to the WHO all people, regardless of their stage of development and their social economic condition, have the right to have access to adequate drinking water. The most efficient and economic technique used for arsenic removal is represented by adsorption. In order to make this remediation technique more affordable and environmentally friendly is important to new materials with advance adsorbent properties. Novelty of present paper is represented by the usage of a new adsorbent material obtained by physical - chemical modification of Amberlite XAD polymers using crown ethers followed by iron doping, due to well-known affinity of arsenic for iron ions. Present paper aims to test the obtained modified Amberlite polymer for arsenic removal from real groundwater by using adsorption in a fixed bed column, establishing in this way a mechanism for the adsorption process. During experimental work was studied the influence of competing ions from real water into the arsenic adsorption process.


1994 ◽  
Vol 29 (12) ◽  
pp. 149-156 ◽  
Author(s):  
Marcus Höfken ◽  
Katharina Zähringer ◽  
Franz Bischof

A novel agitating system has been developed which allows for individual or combined operation of stirring and aeration processes. Basic fluid mechanical considerations led to the innovative hyperboloid design of the stirrer body, which ensures high efficiencies in the stirring and the aeration mode, gentle circulation with low shear forces, excellent controllability, and a wide range of applications. This paper presents the basic considerations which led to the operating principle, the technical realization of the system and experimental results in a large-scale plant. The characteristics of the system and the differences to other stirring and aeration systems are illustrated. Details of the technical realization are shown, which conform to the specific demands of applications in the biological treatment of waste water. Special regard is given to applications in the upgrading of small compact waste water treatment plants.


2020 ◽  
Vol 1 (1) ◽  
pp. 30-36
Author(s):  
Shubha Jayachamarajapura Pranesh ◽  
Diwya Lanka

Background: Textile industries discharge harmful synthetic dyes to nearby water sources. These colour effluents should be treated before discharge to reduce the toxicity caused by synthetic colours. Objective: To synthesize visible light active superstructures to reduce water pollution caused by textile industries. Methods: We have successfully synthesized ZnO/Dy/NiO hybrid nanocomposites using waste curd as fuel by a simple combustion method. The obtained material was able to reduce recombination and enhanced the photocatalytic degradation of organic pollutants. The as-synthesized material was characterized by XRD, absorption spectroscopy, FESEM, EDAX, etc. The obtained hybrid nanostructure was used as a photocatalyst for the degradation of methylene blue under sunlight, UV light as well as in dark. Comparative experiments were carried out with a variation of catalytic load, pH, dye concentrations, etc. for a better understanding of the performance of the catalyst at various conditions. Results and Conclusion: The ternary compound shows wide range of absorption by expanding absorption band both in UV and visible regions. ZnO/Dy/NiO hybrid nanocomposites performed well and showed uniqueness in the activity uder visible light.


2020 ◽  
Author(s):  
André De Faria Pereira Neto ◽  
Leticia Barbosa ◽  
Rodolfo Paolucci

UNSTRUCTURED Billions of people in the world own a smartphone. It is a low-cost, portable computing device with countless features, among which applications stand out, which are programs or software developed to meet a specific goal. A wide range of applications available ranging from entertainment and personal organization to work and education is available currently. It is a vast and profitable market. Health applications have been a means of intervention for different areas, including chronic diseases, epidemics, and health emergencies. A recently published paper in the journal with the highest impact factor in Digital Health (“Journal of Medical Internet Research”) proposes a classification of health applications. This study performs a critical analysis of this organization and presents other sort criteria. This paper also presents and analyzes the “Meu Info Saúde” (“My Health Info”) app – a pioneering government initiative focused on primary care launched by the Oswaldo Cruz Foundation. The application classification proposal that will be presented builds on the intervention strategies in the health-disease process, namely: “Health Promotion”, “Disease Prevention” and “Care, Treatment and Rehabilitation”, as defined by official documents such as the World Health Organization and the Centers for Disease Control and Prevention. Most applications present in the sample are of private and foreign origin, free to download, but with a display of ads or the sale of products and services. The sampled applications were classified as “Health Promotion”, and some applications have also been categorized as “Disease Prevention” or “Care, Treatment or Rehabilitation” because they have multiple functionalities. The applications identified as “Health Promotion” focused only on individuals’ lifestyle and their increased autonomy and self-care management capacity. From this perspective, the apps analyzed in this paper differ from the “Meu Info-Saúde” application developed at Fiocruz.


2020 ◽  
Author(s):  
Salime Goharinezhad

BACKGROUND World Health Organization declared the vaccine hesitancy as a global public health threat in 2019. Since even a slight reduction in vaccine coverage rates can lead to a decrease in herd immunity, it is imperative to explore the underlying factors affecting vaccine hesitancy. in specific contexts, considering socioeconomic and cultural variation, to ensure interventions targeting hesitancy are well formulated and intervened. OBJECTIVE The main objective of this study is to identify underlying factors affecting vaccine hesitancy in Iran. METHODS A framework qualitative study will be conducted in the west of Tehran province in 2020. Participants in the study will be recruited hesitance-parents who extracted from the SIB system (an electronic health record in Iran) to maximize diversity. Interviews will be analyzed based on ''Determinants of Vaccine Hesitancy Matrix'' which developed by the WHO-SAGE Working Group. RESULTS deep understanding from the context-specific reasons for vaccine hesitancy cause to formulate better strategies to address them. The ultimate goal of this study is to inform future policies to increase the uptake of the vaccine in Iran. CONCLUSIONS This result of study will show variety opinions about vaccination among different types of socioeconomic and demographic households. The wide range of reasons related to vaccine hesitancy imply to more comprehensive, context-specific interventions. Today, the most important intervention issues focus on improving information about effectiveness and safety of vaccines, while other interventions for promoting vaccination is need to addressed.


Processes ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 79
Author(s):  
Minghan Luo ◽  
Wenjie Xu ◽  
Xiaorong Kang ◽  
Keqiang Ding ◽  
Taeseop Jeong

The ultraviolet photochemical degradation process is widely recognized as a low-cost, environmentally friendly, and sustainable technology for water treatment. This study integrated computational fluid dynamics (CFD) and a photoreactive kinetic model to investigate the effects of flow characteristics on the contaminant degradation performance of a rotating annular photoreactor with a vacuum-UV (VUV)/UV process performed in continuous flow mode. The results demonstrated that the introduced fluid remained in intensive rotational movement inside the reactor for a wide range of inflow rates, and the rotational movement was enhanced with increasing influent speed within the studied velocity range. The CFD modeling results were consistent with the experimental abatement of methylene blue (MB), although the model slightly overestimated MB degradation because it did not fully account for the consumption of OH radicals from byproducts generated in the MB decomposition processes. The OH radical generation and contaminant degradation efficiency of the VUV/UV process showed strong correlation with the mixing level in a photoreactor, which confirmed the promising potential of the developed rotating annular VUV reactor in water treatment.


Author(s):  
Hernâni Marques ◽  
Pedro Cruz-Vicente ◽  
Tiago Rosado ◽  
Mário Barroso ◽  
Luís A. Passarinha ◽  
...  

Environmental tobacco smoke exposure (ETS) and smoking have been described as the most prevalent factors in the development of certain diseases worldwide. According to the World Health Organization, more than 8 million people die every year due to exposure to tobacco, around 7 million due to direct ETS and the remaining due to exposure to second-hand smoke. Both active and second-hand exposure can be measured and controlled using specific biomarkers of tobacco and its derivatives, allowing the development of more efficient public health policies. Exposure to these compounds can be measured using different methods (involving for instance liquid- or gas-chromatographic procedures) in a wide range of biological specimens to estimate the type and degree of tobacco exposure. In recent years, a lot of research has been carried out using different extraction methods and different analytical equipment; this way, liquid–liquid extraction, solid-phase extraction or even miniaturized procedures have been used, followed by chromatographic analysis coupled mainly to mass spectrometric detection. Through this type of methodologies, second-hand smokers can be distinguished from active smokers, and this is also valid for e-cigarettes and vapers, among others, using their specific biomarkers. This review will focus on recent developments in the determination of tobacco smoke biomarkers, including nicotine and other tobacco alkaloids, specific nitrosamines, polycyclic aromatic hydrocarbons, etc. The methods for their detection will be discussed in detail, as well as the potential use of threshold values to distinguish between types of exposure.


Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1651
Author(s):  
Cristina Arqueros ◽  
Félix Zamora ◽  
Carmen Montoro

Global population growth and water resource scarcity are significant social problems currently being studied by many researchers focusing on finding new materials for water treatment. The aim is to obtain quality water suitable for drinking and industrial consumption. In this sense, an emergent class of crystalline porous materials known as Covalent-Organic Frameworks (COFs) offers a wide range of possibilities since their structures can be designed on demand for specific applications. Indeed, in the last decade, many efforts have been made for their use in water treatment. This perspective article aims to overview the state-of-the-art COFs collecting the most recent results in the field for water detection of pollutants and water treatment. After the introduction, where we overview the classical design strategies on COF design and synthesis for obtaining chemically stable COFs, we summarize the different experimental methodologies used for COFs processing in the form of supported and free-standing membranes and colloids. Finally, we describe the use of COFs in processes involving the detection of pollutants in water and wastewater treatment, such as the capture of organic compounds, heavy metals, and dyes, the degradation of organic pollutants, as well as in desalination processes. Finally, we provide a perspective on the field and the potential technological use of these novel materials.


Toxins ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 451
Author(s):  
José María Gutiérrez ◽  
Laura-Oana Albulescu ◽  
Rachel H. Clare ◽  
Nicholas R. Casewell ◽  
Tarek Mohamed Abd Abd El-Aziz ◽  
...  

A global strategy, under the coordination of the World Health Organization, is being unfolded to reduce the impact of snakebite envenoming. One of the pillars of this strategy is to ensure safe and effective treatments. The mainstay in the therapy of snakebite envenoming is the administration of animal-derived antivenoms. In addition, new therapeutic options are being explored, including recombinant antibodies and natural and synthetic toxin inhibitors. In this review, snake venom toxins are classified in terms of their abundance and toxicity, and priority actions are being proposed in the search for snake venom metalloproteinase (SVMP), phospholipase A2 (PLA2), three-finger toxin (3FTx), and serine proteinase (SVSP) inhibitors. Natural inhibitors include compounds isolated from plants, animal sera, and mast cells, whereas synthetic inhibitors comprise a wide range of molecules of a variable chemical nature. Some of the most promising inhibitors, especially SVMP and PLA2 inhibitors, have been developed for other diseases and are being repurposed for snakebite envenoming. In addition, the search for drugs aimed at controlling endogenous processes generated in the course of envenoming is being pursued. The present review summarizes some of the most promising developments in this field and discusses issues that need to be considered for the effective translation of this knowledge to improve therapies for tackling snakebite envenoming.


Sign in / Sign up

Export Citation Format

Share Document