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Biotechnological Management, Extraction and Recycling of Metals from E-Waste
Published in Abhijit Das, Biswajit Debnath, Potluri Anil Chowdary, Siddhartha Bhattacharyya, Paradigm Shift in E-waste Management, 2022
Satarupa Dey, Biswaranjan Acharya*
Nanoremediation can also be considered as an ideal candidate for remediation of heavy metals from different types of industrial waste. The particles mainly have a size ranging from 10-100nm, and are characterized with high surface area, reactivity, adsorptivity, photocatalytic properties which assist in analytical detection and subsequent remediation. Zero valent iron particles of nanoscale range are extensively used in nanoremediation and can act as an ideal candidate to remediate heavy metals (Liu et al. 2011; Tratnyek and Johnson 2006; Karn et al. 2009). These zero valent iron particles have a metallic iron core which has electron donating power, whereas the surface iron hydroxide attract and absorb charged heavy metals and can function in removal and immobilization of oxyanions such as As(V), Cr(VI), Zn(II), Pb (II), Pd(II) and Ni(II) (Ponder et al. 2000). Aluminium nanoparticles can result in 97% removal of Ni(II) from metal laden solution and can be used as an alternative strategy for the treatment of e-waste (Sharma et al. 2008). Similarly, zeolite aided iron nanoparticles can also be used for adsorption of heavy metals from aqueous samples (Li et al. 2018). Nagarajah et al. (2017) reported, nanomagnetite coated by silica and MgO (MTM) was capable of removing Pb, Cd, Cu mainly by substitution, followed by precipitation mechanism. Despite several advantages the basic technology is still not much evolved for large scale application and also the main drawback is that they tend to self-aggregate and associate with suspended particles and bioaccumulate in the food chain (Karn et al. 2009; Kotnala 2009).
Nanoparticles, Biosurfactants and Microbes in Bioremediation
Published in Vivek Kumar, Rhizomicrobiome Dynamics in Bioremediation, 2021
Charles O. Nwuche, Victor C. Igbokwe, Daniel D. Ajagbe, Chukwudi O. Onwosi
Nanotechnology is presently at the forefront of restoration efforts covering a wide spectrum of environmental contamination. Specifically, several sites previously polluted with hydrocarbons, chlorinated compounds and even heavy metals have been treated successfully using carbon nanomaterials. The application of nanotechnology in the removal or cleanup of environmental pollutants is termed nanoremediation. It is a new development that engages the use of nanomaterials in the recovery and restoration of impacted environments. Nanoremediation is a rapid, cost effective and efficient replacement to the old, tedious and expensive bioremediation approaches. It equally offers clear strategies for preventing, detecting and monitoring the progress of remediation (Rajan 2011). Nanoremediation involves the use of nanomaterials and nanoscale particles such as carbon nanotubes, zeolites and fibres in the transformation and detoxification of pollutants. Nanomaterials have been used to overcome countless limitations often associated with ‘in situ’ remediation when conventional treatment methods such as chemical oxidation and thermal treatment were applied. Presently, nanoscale zero-valent iron (nZVI’s) is the most widely used nanoparticle (Garner and Keller 2014). Their large surface area and excellent reactivity make them best suited for the cleanup or removal of contaminated materials. They have low reduction potential and other beneficial attributes that promote mobility across the soil matrix (Tosco et al. 2014).
Ashless Antiwear and Antiscuffing (Extreme Pressure) Additives
Published in Leslie R. Rudnick, Lubricant Additives, 2017
Liehpao Oscar Farng, Tze-Chi Jao
Nanoremediation is the use of nanoparticles for environmental remediation. During nanoremediation, a nanoparticle agent must be brought into contact with the target contaminant under conditions that allow a detoxifying or immobilizing reaction. Nanofiltration is a membrane filtration based on method that uses nanometer-sized cylindrical through-pores that pass through the membrane at a perpendicular angle. Nanofiltration membranes have pore size from 1 to 10 Å, smaller than that used in microfiltration and ultrafiltration, but just larger than that in reverse osmosis. Some water treatment filtration devices incorporating nanotechnology are already on the market, with more in development.
Nanomaterials for sustainable remediation of chemical contaminants in water and soil
Published in Critical Reviews in Environmental Science and Technology, 2022
Raj Mukhopadhyay, Binoy Sarkar, Eakalak Khan, Daniel S. Alessi, Jayanta Kumar Biswas, K. M. Manjaiah, Miharu Eguchi, Kevin C. W. Wu, Yusuke Yamauchi, Yong Sik Ok
There is a need to develop cost-effective and ecologically benign materials for cleaning up contaminated soil and water. Nanotechnology offers rapid, inexpensive and environmentally safe solutions, and has great potential to reduce contaminant levels to ‘nearly zero’ (Bardos et al., 2018). Nanoremediation of the environment can be defined as the process whereby suitable nanomaterials (NMs) are used for cleaning up environmental contaminants in the soil, water, and air. Nanoremediation technologies can eliminate the need for excavating and transporting contaminated soils because the cleanup process often takes place in-situ (Cai et al., 2019; Fajardo et al., 2020). Furthermore, several approaches can be applied to regenerate and reuse nanomaterials in contaminant treatment applications (e.g., magnetic separation of iron nanoparticles, recovery of metals from spent nanosorbents) (Mehta et al., 2015).
Nanomaterials and nanotechnology for water treatment: recent advances
Published in Inorganic and Nano-Metal Chemistry, 2021
Nanotechnology offers the potential of novel nanomaterials for the treatment of surface water, groundwater, wastewater, and other environmental materials contaminated by toxic metal ions, metal oxides, organic and inorganic solutes, and bio-organisms which includes processes such as reverse osmosis, nanofiltration, ultrafiltration membranes, nanofiber filters and carbon nanotubes. Some nanoremediation methods, particularly the use of nano zero valent iron for groundwater cleanup, have been deployed at full-scale cleanup sites. During nanoremediation, a nanoparticle agent is brought in contact with the target contaminant under conditions that allow a detoxifying or immobilizing reaction; this process typically involves a pump-and-treat process or in situ application.[44]
Amendment additions and their potential effect on soil geotechnical properties: A perspective review
Published in Critical Reviews in Environmental Science and Technology, 2021
Fuming Liu, Shuping Yi, Wan-Huan Zhou, Yong-Zhan Chen, Ming Hung Wong
Nanomaterials or nanoparticles are nano-scale particles used for transforming and detoxifying diverse environmental contaminants in contaminated sites. In the field of nanoremediation, engineered nanomaterials can be classified as carbonaceous nanomaterials (e.g., carbon nanotubes, graphene and derivatives, carbon nanofibers, fullerene, and amorphous carbonaceous composites), metal and metal oxides/sulfides (e.g., Fe0, Al0, FeS, TiO2, ZnO, Ag), magnetic-core composite (e.g., iron, nickel, and cobalt or their oxides and alloys), and naturally occurring materials (e.g., clay). Among the different tested nanoparticles, nanoscale zero-valent iron (nZVI) based nanoparticles are the most extensively used nanoremediation materials in field applications (Adeleye et al., 2016). Nanoremediation is generally applied by injecting large quantities of nanoparticle slurry into treated soil for in situ remediation. Nanoparticles are highly reactive; oxidation, reduction, precipitation, adsorption, and desorption are commonly involved. Generally, these particles can persist in the environmental system in solid state for a long time. Nanoparticle exposure may pose a nano-threat to susceptible living organisms and ecosystems as well. That is why the study of their toxicity (i.e., nanotoxicity in the environment) is a hot research point, as researchers seek to identify the hazards associated with nanoremediation. Nathanail, Gillett, McCaffrey, Nathanail, and Ogden (2016) indicated that the potential for subtle and considerable nanotoxicity raised by chronic nanoparticle exposure at low concentration levels should be considered carefully (Nathanail et al., 2016). On the other hand, nanoparticles are prone to interact with aquifer matrices. In groundwater, these matrices can easily restrain the mobility of nanoparticles by forming an aggregation around the injection well, which may increase the nanoparticle exposure and lead to significant toxicity (Gomes, Dias-Ferreira, Ribeiro, & Pamukcu, 2013). In view of the nanoremediation-induced ecological and ecotoxicological risks, some European Union (EU) states have taken a strong precautionary stance (i.e., Nanoremediation Bill) to control the risks associated with nanoremediation (Bardos et al., 2015). Additionally, as these nanomaterials have high reactivity, the physicochemical properties of soils may significantly change. Such changes may occur in soil buffering capacity, pH value, soil particle size, porosity, conductivity, ion strength, and total carbon (Gomes, Dias-Ferreira, Ribeiro, & Pamukcu, 2014; Chen, Ji, Wang, & Zang, 2017; Jiang et al., 2018).