Application of Nanoparticles for Environmental Remediation

2022 ◽  
pp. 199-222
Author(s):  
Gamze Ersan ◽  
Mahmut Selim Ersan
Keyword(s):  
Organic Matter ◽  
Ionic Strength ◽  
Surface Charge ◽  
Pore Size ◽  
Functional Groups ◽  
Environmental Remediation ◽  
Molecular Size ◽  
Future Research ◽  
Research Needs ◽  
Treatment Mechanisms

In the last decades, numerous research studies have been focused on the mitigation of different classes of contaminants by varying types of NPs. Treatment mechanisms were controlled by properties of contaminants (e.g., organic vs inorganic, molecular size, and hydrophobicity, etc.), NPs (e.g., surface charge, area, pore size, and surface functional groups, etc.), and aqueous water (e.g., organic matter types, pH, ionic strength, surfactants, and temperature). Therefore, this chapter includes (1) a literature summary for the removal of contaminants by carbon- and metal-based NPs, (2) a discussion on the controlling mechanisms for the mitigation of contaminants by carbon- and metal-based NPs, and (3) an evaluation on the application and implication of carbon- and metal-based NPs in environmental studies. This chapter also identifies future research needs and challenges on the application of carbon- and metal-based NPs for environmental remediation.

scholarly journals The effect of agroecosystem management on the distribution of C functional groups in soil organic matter: A review

2021 ◽  
Author(s):  
Yuki Audette ◽  
Katelyn A. Congreves ◽  
Kimberley Schneider ◽  
Geovanna C. Zaro ◽  
Amanda L. P. Nunes ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Functional Groups ◽  
Crop Rotation ◽  
Management Practices ◽  
Soil Health ◽  
The Body ◽  
Future Research ◽  
Microbial Decomposition ◽  
Tillage Practices

AbstractTo improve soil health and to aid in climate change mitigation, the quantity of soil organic matter (SOM) should be maintained or increased over the long run. In doing so, not only the total quantity of SOC but also the stability of SOC must be considered. Stability of SOC increases as a function of resistance to microbial decomposition or microbial substrate use efficiency through chemical, biological, and physical mechanisms including humification, hydrophobic moieties, molecular diversity, and formation of macroaggregates. One of the mechanisms that enhance stability confers changes in the distribution of C functional groups of SOM. To better understand and quantify how these changes are influenced by agricultural management practices, we collected 670 pairwise data from the body of literature that has evaluated changes in the distribution of C functional groups of SOM measured by solid-state 13C NMR spectroscopy. The types of agricultural managements discussed herein include (1) fertilization, (2) tillage, (3) crop rotation, (4) grazing, and (5) liming practices. Our meta-analyses show that these practices modify the distribution of C functional groups of SOM. Fertilization practices were associated with increased O-alkyl groups. Tillage resulted in increases in the SOC consisted of aromatic and carbonyl groups. Crop rotations, especially legume-based rotations, were found to increase the proportion of aromatic groups. Although there are fewer publications on tillage and crop rotation than on fertilization practices, the distribution of C functional groups may be more influenced by crop rotation and tillage practices than fertilization management—and should be a focus of future research.

Application of advanced adsorption processes for dissolved organic matter and heavy metal removal from water sources

2015 ◽  
Author(s):  
◽  
A.K.M. Nazmul Hussain
Keyword(s):  
Organic Matter ◽  
Water Treatment ◽  
Ionic Strength ◽  
Ion Exchange ◽  
Molecular Size ◽  
Hematite Nanoparticles ◽  
Cobalt Ions ◽  
Initial Concentration ◽  
Adsorptive Removal ◽  
Trace Compounds

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] The main objective of this research was to develop an improved understanding of natural organic matter (NOM) and heavy metals removal from two water sources: the City of Columbia McBaine Water Treatment Plant and synthetic water samples prepared in the laboratory. Batch experiments were conducted to evaluate the feasibility of utilizing the adsorption process with magnetite, magnetic ion exchange resin (MIEX), and powdered activated carbon (PAC) as adsorbents to reduce the NOM found in natural groundwater. Control and treated samples were studied to determine the removal degree of dissolved organic matter (DOC) and to verify the impact to the formation potential of disinfection by-products (DBPs). There was no clear correlation found between DOC and disinfection byproducts formation potential (THMFP) over the range of DOC values examined in this study. For MIEX applications, this lack of correlation between DOC removal and DBP could be due to partial dissolution of organic components from MIEX itself. The research provides a framework for using adsorption for the removal of NOM and control of DBP. The presence of common groundwater constituents, such as iron, was found to adversely impact the adsorption capacity of NOM onto MIEX. Possible reasons may include- blocking of the ion-exchange sites on MIEX, and the formation of NOM-Fe complexes that may possess different sorption characteristics from pure NOM. The effects of iron in both Fe2+ and Fe3+ states on the adsorption of NOM onto MIEX were evaluated. The removals of TOCs were found to be higher in oxic conditions whereas the removals of UV254s were found to be higher in anoxic conditions. In oxic conditions, MIEX was capable of removing both NOM and iron effectively when coexisting in raw water. Iron could compete with NOM for exchange sites on MIEX at high dosages (>4 ml/L), which in turn could decrease the NOM removal rate. In anoxic conditions, similar removal patterns were observed as those in oxic conditions, except that MIEX adsorbed less iron with increasing iron content in the water samples. The extent of competitive adsorption was dependent on the initial concentration of trace compounds, the initial concentration of NOM, the molecular size of trace compounds, the molecular size distribution of NOM molecules, and the type and dosage of adsorbents. Experiments were also conducted to study the effects of pH, ionic strength and hematite nanoparticles dosage on the adsorptive removal of Co2+ from aqueous solution. It was observed that adsorption was enhanced in neutral pH conditions, comparing to acidic condition and irrespective of ionic strength. Freundlich models were capable of representing the data more satisfactorily than the Langmuir models. The co-ions removed Co in the order Pb2+> Cu2+ >HA. Hematite nanoparticles derived from ferroxane-AA were deposited on porous alumina tubes to develop tubular ceramic membrane for the removal of Co2+. Ferroane-AA loading on ceramic tube was found to be very low; 0.5 g of ferroxane-AA loaded only 1% and 2.0 g of ferroxane-AA loaded 0.7%. The regeneration process was tested for 4 washing cycles without membrane damage. The results of this study indicate that, with the adsorptive removal of cobalt ions from natural groundwater and the ability to adsorb multiple metal ions simultaneously, hematite nanoparticles may offer a potential and suitable remediation method for the removal of cobalt ions. The ferroxane-AA fabrication process takes place in an aqueous environment, does not involve the use of hazardous substances, and has low energy consumption due to the low firing temperature of the ceramic tube. Furthermore, the generation of liquid wastes on site can be avoided during operation. The membranes can be re-used after washing with a basic solution. The materials can be processed for regeneration in a centralized treatment facility for improved liquid waste management. Its compact and user-friendly design allows it to be deployed at the point of use, while it is also flexible to adapt to a larger scale, suitable for water treatment plants.

Current knowledge on transport and reactivity of technology-critical elements (TCEs) in soil and aquifer environments

2020 ◽  
Vol 17 (2) ◽  
pp. 118 ◽  
Author(s):  
Yasmine Kouhail ◽  
Ishai Dror ◽  
Brian Berkowitz
Keyword(s):  
Porous Media ◽  
Organic Matter ◽  
Ionic Strength ◽  
Natural Organic Matter ◽  
Field Experiments ◽  
Current Knowledge ◽  
Anthropogenic Activities ◽  
Future Research ◽  
Chemical Compositions ◽  
Critical Elements

Environmental contextTechnology-critical elements, widely used in modern industry, are found in the environment as a result of both anthropogenic usage and natural sources. This review describes current knowledge on the transport of technology-critical elements in sand, soils and aquifer environments. The chemical compositions of the soils and groundwaters influence the transport of technology-critical elements, and natural colloids increase their mobility. AbstractTechnology-critical elements (TCEs) are now present in soil and aquifer environments, as a result not only of the geogenic origin but also of the recent anthropogenic activities and release. TCEs can interact with all components of the soil and water, which include inorganic and organic ligands (natural organic matter), clays, mineral surfaces and microorganisms. The literature regarding the transport and fate of TCEs in subsurface porous media (e.g. soil and aquifers) is limited and highly diverse. This review offers a detailed analysis of the existing literature on the transport and fate of TCEs in porous media, and emphasises what is still needed to fully understand their behaviour in the environment. Different modes of TCE transport are presented. First, the mobility of TCEs following interaction with colloids (e.g. natural organic matter, clays) is described. For these cases, an increase in the ionic strength and pH of aqueous solutions shows stronger retention or sorption of TCEs on porous matrices. The transport of nanoparticles (NPs) that contain TCEs is presented as a second mode of mobility. The ionic strength of the solution is the key parameter that controls the transport of cerium nanoparticles in porous media; natural organic matter also increases the mobility of nanoparticles. The third part of this review describes sorption and dissolution processes during transport. Finally, results from the field experiments are reported, which show that rare earth elements and indium are transported in the presence of natural organic matter. We conclude this review with suggested directions for future research.

Understanding Limited Use of Amplification in Infants and Children Who Are Hard of Hearing

2015 ◽  
Vol 25 (1) ◽  
pp. 15-23 ◽  
Author(s):  
Ryan W. McCreery ◽  
Elizabeth A. Walker ◽  
Meredith Spratford
Keyword(s):  
Hard Of Hearing ◽  
Hearing Aid ◽  
Management Strategies ◽  
Infants And Children ◽  
Future Research ◽  
Research Needs ◽  
Case Examples ◽  
Hearing Aid Use ◽  
Wide Range ◽  
In Infants And Children

The effectiveness of amplification for infants and children can be mediated by how much the child uses the device. Existing research suggests that establishing hearing aid use can be challenging. A wide range of factors can influence hearing aid use in children, including the child's age, degree of hearing loss, and socioeconomic status. Audiological interventions, including using validated prescriptive approaches and verification, performing on-going training and orientation, and communicating with caregivers about hearing aid use can also increase hearing aid use by infants and children. Case examples are used to highlight the factors that influence hearing aid use. Potential management strategies and future research needs are also discussed.

Locus of Control, Safety Attitudes and Involvement in Hazardous Events in Indian Army Aviators

2013 ◽  
Vol 3 (1) ◽  
pp. 9-18 ◽  
Author(s):  
Catherine Joseph ◽  
Suhasini Reddy ◽  
Kanwal Kashore Sharma
Keyword(s):  
Locus Of Control ◽  
Future Research ◽  
Research Needs ◽  
Negative Attitudes ◽  
Human Errors ◽  
Safety Attitudes ◽  
Positive Correlation ◽  
Self Confidence

Locus of control (LOC), safety attitudes, and involvement in hazardous events were studied in 205 Indian Army aviators using a questionnaire-based method. A positive correlation was found between external LOC and involvement in hazardous events. Higher impulsivity and anxiety, and decreased self-confidence, safety orientation, and denial were associated with a greater number of hazardous events. Higher external LOC was associated with higher impulsivity, anxiety, and weather anxiety and with lower self-confidence, safety orientation, and denial. Internal LOC was associated with increased self-confidence, safety orientation, and denial. Hazardous events and self-confidence were higher in those involved in accidents than those not involved in accidents. Future research needs to address whether training can effectively modify LOC and negative attitudes, and whether this would cause a reduction in, and better management of, human errors.

Decolorisation of natural organic matter by Phanerochaete chrysosporium: the effect of environmental conditions

2004 ◽  
Vol 4 (4) ◽  
pp. 175-182 ◽  
Author(s):  
K. Rojek ◽  
F.A. Roddick ◽  
A. Parkinson
Keyword(s):  
Organic Matter ◽  
Ionic Strength ◽  
Natural Organic Matter ◽  
Phanerochaete Chrysosporium ◽  
Fungal Growth ◽  
Low Ph ◽  
Colour Removal ◽  
Humic Material ◽  
Carbon And Nitrogen ◽  
Carbon And Nitrogen Content

Phanerochaete chrysosporium was shown to rapidly decolorise a solution of natural organic matter (NOM). The effect of various parameters such as carbon and nitrogen content, pH, ionic strength, NOM concentration and addition of Mn2+ on the colour removal process was investigated. The rapid decolorisation was related to fungal growth and biosorption rather than biodegradation as neither carbon nor nitrogen limitation, nor Mn2+ addition, triggered the decolorisation process. Low pH (pH 3) and increased ionic strength (up to 50 g L‒1 added NaCl) led to greater specific removal (NOM/unit biomass), probably due to increased electrostatic bonding between the humic material and the biomass. Adsorption of NOM with viable and inactivated (autoclaved or by sodium azide) fungal pellets occurred within 24 hours and the colour removal depended on the viability, method of inactivation and pH. Colour removal by viable pellets was higher under the same conditions, and this, combined with desorption data, confirmed that fungal metabolic activity was important in the decolorisation process. Overall, removals of up to 40–50% NOM from solution were obtained. Of this, removal by adsorption was estimated as 60–70%, half of which was physicochemical, the other half metabolically-dependent biosorption and bioaccumulation. The remainder was considered to be removed by biodegradation, although some of this may be ascribed to bioaccumulation and metabolically-dependent biosorption.

Collaborative Remembering in Dementia: A Focus on Joint Activities

2018 ◽  
Author(s):  
Lars-Christer Hydén ◽  
Mattias Forsblad
Keyword(s):  
Everyday Life ◽  
Past Research ◽  
Research Field ◽  
Future Research ◽  
Research Needs ◽  
Joint Activities ◽  
Do So ◽  
Dementia Diseases

In this chapter we consider collaborative remembering and joint activates in everyday life in the case of people living with dementia. First, we review past research of practices that scaffolds the participation of persons with dementia in everyday chores under different stages of dementia diseases. We do so by suggesting three analytical types of scaffolding: when the scaffolding practices (i) frame the activity, (ii) guide actions, or (iii) are part of repair activities. Second, we review two aspects of collaborative remembering that are especially important in the case of dementia: training of scaffolding practices, and the sustaining and presentation of identities through collaborative storytelling. Finally, theoretical and methodological tendencies of the research field are summarized and future research needs are formulated.

A Scoping Review of Resilience in Survivors of Human Trafficking

2021 ◽  
pp. 152483802098556
Author(s):  
Logan Knight ◽  
Yitong Xin ◽  
Cecilia Mengo
Keyword(s):  
Interpersonal Relationships ◽  
Scoping Review ◽  
National Origin ◽  
Future Research ◽  
Research Needs ◽  
Standardized Measures ◽  
Factors Associated ◽  
Current State ◽  
Case Files ◽  
Sexual Trafficking

Resilience is critical among survivors of trafficking as they are mostly vulnerable populations who face multiple adversities before, during, and after trafficking. However, resilience in survivors of trafficking is understudied. This scoping review aims to clarify the current state of knowledge, focusing on definitions of resilience, how resilience has been studied, and factors associated with resilience among survivors. Five databases were searched using key words related to trafficking and resilience. Studies were included if they were published in English between 2000 and 2019 and focused on resilience with the study design including at least one of these four features: (a) use of standardized measures of resilience, (b) qualitative descriptions of resilience, (c) participants were survivors or professionals serving survivors, and (d) data sources such as case files or program manuals directly pertained to survivors. Eighteen studies were identified. Findings indicated that resilience was primarily described as emergent from interactions between the survivor and the environment. Resilience in trafficking appeared largely similar to resilience in other kinds of victimization. Nonetheless, trafficking survivors also may display resilience in alternative ways such as refusing treatment. Positive interpersonal relationships were the most commonly mentioned resilience factor. In addition, current research lacks studies featuring longitudinal designs, interventions, participatory methods, types of trafficking other than sexual trafficking, and demographic characteristics such as age, gender, and national origin. Future research needs to establish definitions and measures of resilience that are culturally and contextually relevant to survivors and build knowledge necessary for designing and evaluating resilience-enhancing interventions.

scholarly journals Simulation of methane adsorption in diverse organic pores in shale reservoirs with multi-period geological evolution

2021 ◽  
Author(s):  
Shangbin Chen ◽  
Chu Zhang ◽  
Xueyuan Li ◽  
Yingkun Zhang ◽  
Xiaoqi Wang
Keyword(s):  
Organic Matter ◽  
Pore Size ◽  
Adsorption Capacity ◽  
Thermal Evolution ◽  
Methane Adsorption ◽  
Storage Site ◽  
Pressure Sensitivity ◽  
Adsorption Characteristics ◽  
Shale Reservoirs ◽  
Organic Pores

AbstractIn shale reservoirs, the organic pores with various structures formed during the thermal evolution of organic matter are the main storage site for adsorbed methane. However, in the process of thermal evolution, the adsorption characteristics of methane in multi type and multi-scale organic matter pores have not been sufficiently studied. In this study, the molecular simulation method was used to study the adsorption characteristics of methane based on the geological conditions of Longmaxi Formation shale reservoir in Sichuan Basin, China. The results show that the characteristics of pore structure will affect the methane adsorption characteristics. The adsorption capacity of slit-pores for methane is much higher than that of cylindrical pores. The groove space inside the pore will change the density distribution of methane molecules in the pore, greatly improve the adsorption capacity of the pore, and increase the pressure sensitivity of the adsorption process. Although the variation of methane adsorption characteristics of different shapes is not consistent with pore size, all pores have the strongest methane adsorption capacity when the pore size is about 2 nm. In addition, the changes of temperature and pressure during the thermal evolution are also important factors to control the methane adsorption characteristics. The pore adsorption capacity first increases and then decreases with the increase of pressure, and increases with the increase of temperature. In the early stage of thermal evolution, pore adsorption capacity is strong and pressure sensitivity is weak; while in the late stage, it is on the contrary.

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