scholarly journals Characterization Techniques as Supporting Tools for the Interpretation of Biochar Adsorption Efficiency in Water Treatment: A Critical Review

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 5063
Author(s):  
Michele Castiglioni ◽  
Luca Rivoira ◽  
Irene Ingrando ◽  
Massimo Del Bubba ◽  
Maria Concetta Bruzzoniti
Keyword(s):  
Water Treatment ◽  
Water Purification ◽  
Low Cost ◽  
Efficiency Index ◽  
Adsorption Efficiency ◽  
The Past ◽  
Physicochemical Features ◽  
And Performance ◽  
The Individual ◽  
Significant Attention

Over the past decade, biochar (BC) has received significant attention in many environmental applications, including water purification, since it is available as a low-cost by-product of the energetic valorisation of biomass. Biochar has many intrinsic characteristics, including its porous structure, which is similar to that of activated carbon (AC), which is the most widely used sorbent in water treatment. The physicochemical and performance characteristics of BCs are usually non-homogenously investigated, with several studies only evaluating limited parameters, depending on the individual perspective of the author. Within this review, we have taken an innovative approach to critically survey the methodologies that are generally used to characterize BCs and ACs to propose a comprehensive and ready-to-use database of protocols. Discussion about the parameters of chars that are usually correlated with adsorption performance in water purification is proposed, and we will also consider the physicochemical properties of pollutants (i.e., Kow). Uniquely, an adsorption efficiency index BC/AC is presented and discussed, which is accompanied by an economic perspective. According to our survey, non-homogeneous characterization approaches limit the understanding of the correlations between the pollutants to be removed and the physicochemical features of BCs. Moreover, the investigations of BC as an adsorption medium necessitate dedicated parallel studies to compare BC characteristics and performances with those of ACs.

scholarly journals Chitosan-Based Nanocomposite Polymeric Membranes for Water Purification—A Review

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2091
Author(s):  
Angela Spoială ◽  
Cornelia-Ioana Ilie ◽  
Denisa Ficai ◽  
Anton Ficai ◽  
Ecaterina Andronescu
Keyword(s):  
Water Purification ◽  
Antioxidant Activities ◽  
Low Cost ◽  
Synthetic Polymers ◽  
Water Systems ◽  
Polymeric Membranes ◽  
Wastewater Purification ◽  
Toxic Compounds ◽  
The Past ◽  
Materials Used

During the past few years, researchers have focused their attention on developing innovative nanocomposite polymeric membranes with applications in water purification. Natural and synthetic polymers were considered, and it was proven that chitosan-based materials presented important features. This review presents an overview regarding diverse materials used in developing innovative chitosan-based nanocomposite polymeric membranes for water purification. The first part of the review presents a detailed introduction about chitosan, highlighting the fact that is a biocompatible, biodegradable, low-cost, nontoxic biopolymer, having unique structure and interesting properties, and also antibacterial and antioxidant activities, reasons for using it in water treatment applications. To use chitosan-based materials for developing nanocomposite polymeric membranes for wastewater purification applications must enhance their performance by using different materials. In the second part of the review, the performance’s features will be presented as a consequence of adding different nanoparticles, also showing the effect that those nanoparticles could bring on other polymeric membranes. Among these features, pollutant’s retention and enhancing thermo-mechanical properties will be mentioned. The focus of the third section of the review will illustrate chitosan-based nanocomposite as polymeric membranes for water purification. Over the last few years, researchers have demonstrated that adsorbent nanocomposite polymeric membranes are powerful, important, and potential instruments in separation or removal of pollutants, such as heavy metals, dyes, and other toxic compounds presented in water systems. Lastly, we conclude this review with a summary of the most important applications of chitosan-based nanocomposite polymeric membranes and their perspectives in water purification.

From “Observer to Activist”: Documentary Memory, Oral History, and Studs Terkel's “Essence” Narratives

2010 ◽  
Vol 46 (1) ◽  
pp. 103-119 ◽  
Author(s):  
ANDREA GUSTAVSON
Keyword(s):  
Oral History ◽  
Social Action ◽  
Political Movements ◽  
Subjective Memory ◽  
The Past ◽  
Hard Times ◽  
History Of ◽  
Three Stages ◽  
And Performance ◽  
The Individual

Over several decades of interviewing people and crafting their words into published works, Studs Terkel defined, expanded, and challenged the field of oral history. Terkel often described his methods as similar to those of a “prospector for gold” sifting through the statements of his subjects to create essays that reveal each person's “essence.” Drawing on his planning documents, interview transcripts, manuscripts and published texts, I trace Terkel's approach to oral history through two of his best-known works – Hard Times and “The Good War” – and through three stages: his planning and performance of interviews, his editing of the individual transcripts, and his construction of the completed text. I conclude by considering the implications of Terkel's unconventional approach to oral history and the ways in which his methodology may reflect his long history of involvement with progressive political movements. Terkel crafted his subject's narratives into texts I term “documentary memory”; he insisted that his works are subjective “memory books” but also employed a documentary rhetoric of objectivity. Terkel believed telling stories of the past to be a form of social action and he used his texts about the past to comment politically on his present – his “memory books” document earlier periods in American history relevant to the cultural moment in which he published.

scholarly journals IMPROVEMENT AND PERFORMANCE EVALUATION OF A SYSTEM FOR MONITORING ROTATIONS AND DISPLACEMENTS OF BRIDGES BASED ON LASER POINTER AND DIGITAL PHOTOGRAMMETRY

2019 ◽  
Vol XLII-2/W18 ◽  
pp. 1-5
Author(s):  
G. Artese
Keyword(s):  
Low Cost ◽  
Previous Method ◽  
Digital Photogrammetry ◽  
Laser Pointer ◽  
Generic Point ◽  
Elastic Line ◽  
High Brightness ◽  
Transverse Rotation ◽  
And Performance ◽  
The Individual

Abstract. A system for monitoring rotations and displacements of bridges based on laser pointer and digital photogrammetry is described. The system uses three common laser pointers and image processing. The inclination of the elastic line is measured by analysing the individual frames of an HD video of the laser beam footprint projected onto a flat target. The methodology, able to conjugate a high precision, low cost, and easiness of use, is an evolution of a method developed at University of Calabria, Italy. The use of three laser pointers allows to improve the performance of the previous method, obtaining both displacements and rotations at a generic point of the bridge deck, and deriving the transverse rotation of the deck cross section. The investigated method exploits the laser pointers’ property to provide a steady pointing direction, a long-range and a high-brightness visible imprint. The method and the results of an experimental test are described and discussed.

scholarly journals Facilitated crystal handling using a simple device for evaporation reduction in microtiter plates

2021 ◽  
Vol 54 (1) ◽  
pp. 376-382
Author(s):  
Tatjana Barthel ◽  
Franziska U. Huschmann ◽  
Dirk Wallacher ◽  
Christian G. Feiler ◽  
Gerhard Klebe ◽  
...  
Keyword(s):  
Low Cost ◽  
Simple Device ◽  
Diffraction Experiment ◽  
Macromolecular Crystallography ◽  
The Past ◽  
Microtiter Plates ◽  
The Individual ◽  
Evaporation Reduction

In the past two decades, most of the steps in a macromolecular crystallography experiment have undergone tremendous development with respect to speed, feasibility and increase of throughput. The part of the experimental workflow that is still a bottleneck, despite significant efforts, involves the manipulation and harvesting of the crystals for the diffraction experiment. Here, a novel low-cost device is presented that functions as a cover for 96-well crystallization plates. This device enables access to the individual experiments one at a time by its movable parts, while minimizing evaporation of all other experiments of the plate. In initial tests, drops of many typically used crystallization cocktails could be successfully protected for up to 6 h. Therefore, the manipulation and harvesting of crystals is straightforward for the experimenter, enabling significantly higher throughput. This is useful for many macromolecular crystallography experiments, especially multi-crystal screening campaigns.

scholarly journals Interdigitated Electrophotocatalytic Cell for Water Purification

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Guy Shemer ◽  
Yaron Paz
Keyword(s):  
Water Purification ◽  
Short Distance ◽  
Rhodamine 6G ◽  
Low Cost ◽  
Oxygen Species ◽  
Positive Bias ◽  
Self Assembled Monolayer ◽  
Interdigitated Electrodes ◽  
Activated Oxygen ◽  
And Performance

The preparation, characterization, and performance of an electrophotocatalytic cell, made of low-cost, planar interdigitated electrodes is reported hereby. The operation of the cell under small positive bias was demonstrated by photocatalytically degrading the dye rhodamine 6G in solution as well as by monitoring the degradation of self-assembled monolayer chemisorbed on the TiO2electrode. Results point out to the importance of activated oxygen species formed in the process and suggest that the short distance between the two electrodes provides a way to utilize the activated oxygen species formed at the negatively biased electrode.

scholarly journals Precision and Limits of Detection for Selected Commercially Available, Low-Cost Carbon Dioxide and Methane Gas Sensors

Sensors ◽  
2019 ◽  
Vol 19 (14) ◽  
pp. 3157 ◽  
Author(s):  
Wesley T. Honeycutt ◽  
M. Tyler Ley ◽  
Nicholas F. Materer
Keyword(s):  
Carbon Dioxide ◽  
Low Cost ◽  
Detection Limits ◽  
Detection Range ◽  
Methane Gas ◽  
Accuracy And Precision ◽  
Sensor Platform ◽  
Industrial Monitoring ◽  
And Performance ◽  
The Individual

The performance of a sensor platform for environmental or industrial monitoring is sensitive to the cost and performance of the individual sensor elements. Thus, the detection limits, accuracy, and precision of commercially available, low-cost carbon dioxide and methane gas concentration sensors were evaluated by precise measurements at known gas concentrations. Sensors were selected based on market availability, cost, power consumption, detection range, and accuracy. A specially constructed gas mixing chamber, coupled to a precision bench-top analyzer, was used to characterize each sensor during a controlled exposure to known gas concentrations. For environmental monitoring, the selected carbon dioxide sensors were characterized around 400 ppm. For methane, the sensor response was first monitored at 0 ppm, close to the typical environmental background. The selected sensors were then evaluated at gas concentrations of several thousand ppm. The determined detection limits accuracy, and precision provides a set of matrices that can be used to evaluate and select sensors for integration into a sensor platform for specific applications.

scholarly journals Evaluation of use, acceptability, and effectiveness of household water filter systems in Honduras, 2016–2017

2018 ◽  
Vol 8 (4) ◽  
pp. 809-816
Author(s):  
Kirsten Fagerli ◽  
Jacqueline Hurd ◽  
Emma Wells ◽  
Jarred McAteer ◽  
Sunkyung Kim ◽  
...  
Keyword(s):  
Water Quality ◽  
Water Treatment ◽  
Program Implementation ◽  
Water Filter ◽  
E Coli ◽  
The Past ◽  
Quality Guidelines ◽  
Household Water ◽  
And Performance

Abstract We evaluated a household hollow fiber water filter program in 11 Honduran villages by assessing filter uptake and water quality. Filters were purchased by 90% of households; of these, 94% reported use within the past week. When comparing water treatment methods between baseline and follow-up, there were increases in the proportion of households reporting water treatment (74% vs. 93%, p < 0.001) and treatment by filtration (19% vs. 85%, p < 0.001), and decreased purchase of bottled water (44% vs 6%, p < 0.001), indicating acceptability of the water filtration systems. There was a significant decrease in the presence of Escherichia coli in water samples taken from 35 households at baseline and follow-up in water filter systems (p < 0.001). As a result, 68% of samples met WHO water quality guidelines (no detectable E. coli) 6–12 months after program implementation. Observations of filter stands revealed a 6-inch gap between the top (reservoir) bucket and bottom (filtrate recipient) bucket that could have permitted animals, insects, hands, or other objects to touch filtered water. We recommend a redesign of filter stands to eliminate the gap between buckets, and a longer-term follow-up to assess filter durability and performance.

Application of Geopolymer Composites in Wastewater Treatment

2019 ◽  
pp. 131-149
Author(s):  
Victor Odhiambo Shikuku ◽  
Tome Sylvain
Keyword(s):  
Heavy Metals ◽  
Wastewater Treatment ◽  
Water Treatment ◽  
Low Cost ◽  
Environmentally Benign ◽  
Adsorption Efficiency ◽  
Adsorption Mechanisms ◽  
Synthesis Properties ◽  
Removal Of Heavy Metals ◽  
Geopolymer Composites

Geopolymers are amorphous aluminosilicates with some varied applications. However, the use of geopolymers in water treatment is a relatively new subject. This chapter discusses developments in synthesis, properties and applications of geopolymers and their composites for removal of heavy metals and dyes from water including reduction of hardness in water. The adsorption mechanisms and effects of various environmental conditions on adsorption efficiency are also highlighted. The chapter demonstrates that geopolymers are low cost and environmentally benign materials for wastewater treatment and offers opportunities as alternative adsorbents for sequestration of various pollutants from water subject to further investigations.

Synthesis of Zeolite from Water Treatment Sludge and its Application to the Removal of Brilliant Green

2018 ◽  
Vol 766 ◽  
pp. 111-116
Author(s):  
Khemmakorn Gomonsirisuk ◽  
Kotchakorn Yotyiamkrae ◽  
Malee Prajuabsuk ◽  
Saisamorn Lumlong ◽  
Pharit Kamsri ◽  
...  
Keyword(s):  
Water Treatment ◽  
Brilliant Green ◽  
Low Cost ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Adsorption Efficiency ◽  
Water Treatment Sludge ◽  
Aged Material ◽  
Adsorption Kinetics And Isotherm ◽  
Sem Analyses

In this work, water treatment sludge from the water treatment plant was used to synthesize zeolite material. In the synthesis, the washed sludge was mixed with sodium hydroxide and then heated at 600ºC for 6 h. After agitation, the aged material was heated in a water bath at 80ºC for different period of aging times. Based on XRD and SEM analyses, Faujasite zeolite was obtained. Then, the feasibility of employing the obtained zeolite as adsorbent for Brilliant Green (BG) removal was investigated. The effect of adsorbent dosage and contact time were examined. Adsorption kinetics and isotherm were also evaluated. The results showed that the obtained zeolite has potential for applying as low-cost adsorbent for the removal of BG from wastewater with higher than 97% adsorption efficiency.

Graphene Nanoplatelets-Based Self-Sensing Cementitious Composites

2016 ◽  
Author(s):  
Zhangfan Jiang ◽  
Osman E. Ozbulut ◽  
Devin K. Harris
Keyword(s):  
Carbon Nanofiber ◽  
Low Cost ◽  
Graphene Nanoplatelets ◽  
Cementitious Composites ◽  
Cement Composites ◽  
The Past ◽  
Compressive Loads ◽  
Reinforced Cement ◽  
Functional Fillers ◽  
Significant Attention

Over the past two decades, numerous research studies have been conducted to explore behavior of self-sensing cementitious composites with different functional fillers. Most of these studies investigated the use of fillers such as carbon nanofiber (CNF), carbon black, and carbon nanotubes (CNTs) in cement composites to develop a multifunctional material. Since its discovery in 2004, graphene has also raised significant attention as 2D nanoscale reinforcement for composite materials. The planar structure of graphene sheets provides more contact area with the host material. However, high cost and dispersion difficulties are among the drawbacks of graphene. More recently, graphene nanoplatelets (GNPs), which have very thin but wide aspect ratio, are drawing the graphene market due to their advantages such as ease of processing and excellent material properties at a very low cost. The application of two-dimensional graphene nanoplatelets in cementitious composites has yet to gain widespread attention. This paper investigates the self-sensing capabilities of GNP-reinforced hydraulic Portland cement composites. In particular, the effects of GNP content on the electrical properties and piezoresistive characteristics of mortar specimens are explored. In addition, a simple fabrication method that does not require special treating procedures such as ultrasonication and chemical (covalent) treatments for the dispersion of GNPs is pursued. The GNPs used in this study have an average thickness of 8 nanometers and a diameter of 25 microns. Standard prismatic mortar specimens containing different GNP concentrations are prepared using three different mixing procedures. The resistivity of the specimens is measured using a four-point probe method. The piezoresistive response of GNP-reinforced cement composites is evaluated under cyclic compressive loads.

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