Occurrence, formation, environmental fate and risks of environmentally persistent free radicals in biochars

Odinga, Emmanuel Stephen; Waigi, Michael Gatheru; Gudda, Fredrick Owino; Wang, Jian; Yang, Bing; Hu, Xiaojie; Li, Shunyao; Gao, Yanzheng

doi:10.1016/j.envint.2019.105172

Cited by 150 publications

(75 citation statements)

References 218 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, we see that biochar as an adsorbent may require additional processes of desorption and that this could cause potentially economic drawbacks. Most commonly used biochars contain a significant amount of heavy metals, thereby increasing the risk of pollution due to excess desorption of these heavy metals [140][141][142]. Moreover, ref.…”

Section: Potential Drawbacks Of Using Biochar As An Adsorbentmentioning

confidence: 99%

“…Moreover, ref. [140] extensively studied the effects of environmentally persistent free radicals on wastewater and soil. The free radicals (produced under certain carbonization and pyrolysis conditions), which may mobilize, may pose a significant threat to the environment if they are not monitored and managed.…”

Section: Potential Drawbacks Of Using Biochar As An Adsorbentmentioning

confidence: 99%

“…The free radicals (produced under certain carbonization and pyrolysis conditions), which may mobilize, may pose a significant threat to the environment if they are not monitored and managed. Furthermore, [140] research led to the conclusion that even though biochar finds a plethora of applications in various fields, it still possesses a significant threat as a pollutant to the environment if not used properly. A similar study was conducted by [141], in which the effect of temperature and raw material on biochar toxicity was studied.…”

Section: Potential Drawbacks Of Using Biochar As An Adsorbentmentioning

confidence: 99%

See 2 more Smart Citations

Biochar as an Eco-Friendly and Economical Adsorbent for the Removal of Colorants (Dyes) from Aqueous Environment: A Review

Srivatsav¹,

Bhargav²,

Shanmugasundaram³

et al. 2020

Water

160

View full text Add to dashboard Cite

Dyes (colorants) are used in many industrial applications, and effluents of several industries contain toxic dyes. Dyes exhibit toxicity to humans, aquatic organisms, and the environment. Therefore, dyes containing wastewater must be properly treated before discharging to the surrounding water bodies. Among several water treatment technologies, adsorption is the most preferred technique to sequester dyes from water bodies. Many studies have reported the removal of dyes from wastewater using biochar produced from different biomass, e.g., algae and plant biomass, forest, and domestic residues, animal waste, sewage sludge, etc. The aim of this review is to provide an overview of the application of biochar as an eco-friendly and economical adsorbent to remove toxic colorants (dyes) from the aqueous environment. This review highlights the routes of biochar production, such as hydrothermal carbonization, pyrolysis, and hydrothermal liquefaction. Biochar as an adsorbent possesses numerous advantages, such as being eco-friendly, low-cost, and easy to use; various precursors are available in abundance to be converted into biochar, it also has recyclability potential and higher adsorption capacity than other conventional adsorbents. From the literature review, it is clear that biochar is a vital candidate for removal of dyes from wastewater with adsorption capacity of above 80%.

show abstract

Section: Potential Drawbacks Of Using Biochar As An Adsorbentmentioning

confidence: 99%

Section: Potential Drawbacks Of Using Biochar As An Adsorbentmentioning

confidence: 99%

Section: Potential Drawbacks Of Using Biochar As An Adsorbentmentioning

confidence: 99%

See 1 more Smart Citation

Biochar as an Eco-Friendly and Economical Adsorbent for the Removal of Colorants (Dyes) from Aqueous Environment: A Review

Srivatsav¹,

Bhargav²,

Shanmugasundaram³

et al. 2020

Water

160

View full text Add to dashboard Cite

show abstract

“…[ 149 ] OFGs on the surface of biochar as a nonmetallic carbon‐based catalysts have been suggested as the catalytic functional groups, such as OH, [ 150 ] COOH, [ 151 ] CO, [ 152 ] etc. Researcher found that the homolytic cleavage of the CO in lignin results in the formation of large quantities of PFRs, [ 153 ] which were benefit to catalytic reaction process. Besides, OFGs can be modified by physical and chemical methods, such as CO 2 ‐activated, acid/base treatment, chemical oxidation, to increase the active sites on the surface of biochar and improve the catalytic performance of activating PS/H 2 O 2 to degrade pollutants.…”

Section: Conversion Of Biomasses Into Biochar Catalystsmentioning

confidence: 99%

Hydrothermal and Pyrolytic Conversion of Biomasses into Catalysts for Advanced Oxidation Treatments

Zheng

et al. 2020

Adv Funct Materials

View full text Add to dashboard Cite

Biomasses are very important natural products. Transferring biomass into catalysts for the advanced oxidation process (AOP) via heat treatment has attracted extensive attention. This review systematically introduces and summarizes two kinds of innovative biomass‐based catalysts according to the treating temperature. At low temperature (<300 °C), biomasses are converted into hydrothermal carbonation carbon (HTCC) with semiconductive properties for photocatalysis application. At high temperature (>300 °C), by contrast, the products lose their semiconductive nature and become a conductive carbon‐based conductor (biochar). They usually work as AOP catalysts by activating oxidant of O2, H2O2, and peroxysulfate for environmental treatment. This review summarizes and compares HTCC and biochar according to their formation process, structure, catalytic mechanism, and key points for the activity enhancement. The active units in HTCC are the sp2‐hybridized polyfuran unit while those in biochar are the persistent free radicals, nitrogen‐containing unit, or defects. HTCC converts water into OH radicals by using the photoexcited electron/hole pairs induced by solar illumination, while biochar activates oxidants via the active unit on its surface. More importantly, this review summarizes and demonstrates the key points to obtain high‐efficiency HTCC and biochar catalysts. Finally, conclusions are drawn and the future aspects for biomass‐based catalysis are given.

show abstract

“…In the past, the term 'radical' was used to designate a substituent group bound to a molecular entity, as opposed to 'free radical', which nowadays is simply called radical. The bound entities may be called groups or substituents, but should no longer be called radicals" [6].…”

Section: Modern Understandingmentioning

confidence: 99%

Before Radicals Were Free – the Radical Particulier of de Morveau

Constable

Housecroft

2020

Chemistry

View full text Add to dashboard Cite

show abstract

Occurrence, formation, environmental fate and risks of environmentally persistent free radicals in biochars

Cited by 150 publications

References 218 publications

Biochar as an Eco-Friendly and Economical Adsorbent for the Removal of Colorants (Dyes) from Aqueous Environment: A Review

Biochar as an Eco-Friendly and Economical Adsorbent for the Removal of Colorants (Dyes) from Aqueous Environment: A Review

Hydrothermal and Pyrolytic Conversion of Biomasses into Catalysts for Advanced Oxidation Treatments

Before Radicals Were Free – the Radical Particulier of de Morveau

Contact Info

Product

Resources

About