Parmila Devi | University of British Columbia Okanagan (original) (raw)

Papers by Parmila Devi

Environmental Chemistry for a Sustainable World, 2021

Magnetic adsorbents are increasingly gaining attention as a focus of research for contaminant rem... more Magnetic adsorbents are increasingly gaining attention as a focus of research for contaminant removal from water and wastewater due to their low cost, easy synthesis and separation from aqueous medium. However, the commercial applications of zero-valent iron (ZVI) and iron oxides are limited due to particle agglomeration and low oxidation stability. The agglomeration behavior of ZVI and particle oxidative stability can be enhanced by modification of magnetic adsorbents using an appropriate stabilization procedure such as surface coating or functionalization. This chapter systematically describes the recent advances in modification methods of magnetic adsorbents for contaminant removal from water and wastewater. Various modification methods including carbon stabilization, polymer coating, inorganic oxide impregnation, functionalization, and miscellaneous stabilization procedures are summarized. These stabilization procedures can enhance the adsorption capacities of magnetic adsorbents by expanding the surface area and pore volume of the adsorbents and generating new active sites and/or functional groups on the adsorbent surface. The key process parameters and relevant published data along with the results of these studies have been discussed.

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Critical Reviews in Environmental Science and Technology, 2016

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Environmental science and pollution research international, 2016

Risk assessment and technical feasibility of brick formation from exhausted paper mill sludge der... more Risk assessment and technical feasibility of brick formation from exhausted paper mill sludge derived biochar obtained after its use as an adsorbent for the treatment of effluent containing pentachlorophenol was studied. The bricks were prepared by geopolymerization mechanism in presence of sodium hydroxide, and the extent of geopolymerization was determined on the basis of crystal structure, surface functionalities, and surface morphology of the bricks. The preparation parameters (sodium hydroxide dosage, initial water and calcium carbonate content and curing temperature) were optimized and the results were analyzed in terms of compressive strength, water absorption, and abrasion index. Risk assessment of heavy metals was performed to determine the contamination level and overall hazard index of the biochar-based geopolymer bricks. Hazard quotient and hazard index were calculated to assess the overall non-carcinogenic risk posed by selected heavy metals via ingestion and dermal con...

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The Science of the total environment, 2017

Sludge based adsorbents are widely used for the removal of various pollutants from water and wast... more Sludge based adsorbents are widely used for the removal of various pollutants from water and wastewater systems and the available data is much diversified. The purpose of this review is to organize and critically review the scattered available information on the potential of use of sludge based adsorbents for the removal of various pollutants. It was observed that performance of the sludge based adsorbents varies depending on the type of pollutants, type of precursor sludge, carbonization time-temperature profile and the type of activation conditions used. The variation in pyrolysis and activation conditions found to directly affect the adsorbent properties, adsorption capacity and the mechanism of pollutant removal by sludge based adsorbents. The interaction mechanisms of pollutants with adsorbent surface found to have a detrimental effect on desorption and regeneration of the adsorbents and its recycling potential. Therefore, desorption and regeneration technique used for recycle ...

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Bioresource Technology, 2015

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Bioresource Technology, 2014

The zero-valent iron magnetic biochar composites (ZVI-MBC) were synthesized from the paper mill s... more The zero-valent iron magnetic biochar composites (ZVI-MBC) were synthesized from the paper mill sludge biochar and used for the treatment of the synthetic and real effluent containing pentachlorophenol (PCP). During the synthesis of ZVI-MBC, NaBH4 was used as the reducing agent to reduce Fe(II) to Fe(0) and cetyltrimethylammonium bromide was added as surfactant. The effect of the molar ratio of FeSO4 to NaBH4, dose of the surfactant and the ZVI to biochar ratio on the PCP removal efficiency was investigated. It was found that the ZVI-MBC combines the advantages of biochar and ZVI particles for the simultaneous adsorption and dechlorination of PCP in the effluent and the complete removal of PCP was obtained. The ageing tests showed that biochar prevents the formation of oxide film on the ZVI particles and leaching tests confirmed the stability of ZVI on biochar matrix as very low iron leaching was noticed.

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Bioresource Technology, 2014

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Journal of Clean Energy Technologies, 2014

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Children are vulnerable to heavy metal contamination through consumption of candies and chocolate... more Children are vulnerable to heavy metal contamination
through consumption of candies and chocolates.
Considering this representative samples (69) of candies
and chocolates based on cocoa, milk and sugar were
analyzed for selected heavy metals by means of flame
atomic absorption spectrometry. The average concentration
of Zn, Pb, Ni, and Cd was found to be 2.52 ± 2.49, 2.0
± 1.20, 0.84 ± 1.35, and 0.17 ± 0.22 μg/g respectively.
Results indicate that cocoa-based candies have higher
metal content than milk- or sugar-based candies. The daily
dietary intake of metals for children eating candies and
chocolates was also calculated, and results indicated
highest intake of Pb and Zn followed by Ni, Cd, and Cu.
Comparison of the current study results with other studies
around the globe shows that the heavy metal content in
candies and chocolates is lower in India than reported
elsewhere. However, to reduce the further dietary exposure

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The zero-valent iron magnetic biochar composites (ZVI-MBC) were synthesized from the paper mill s... more The zero-valent iron magnetic biochar composites (ZVI-MBC) were synthesized from the paper mill
sludge biochar and used for the treatment of the synthetic and real effluent containing pentachlorophenol
(PCP). During the synthesis of ZVI-MBC, NaBH4 was used as the reducing agent to reduce Fe(II) to
Fe(0) and cetyltrimethylammonium bromide was added as surfactant. The effect of the molar ratio of
FeSO4 to NaBH4, dose of the surfactant and the ZVI to biochar ratio on the PCP removal efficiency was
investigated. It was found that the ZVI-MBC combines the advantages of biochar and ZVI particles for
the simultaneous adsorption and dechlorination of PCP in the effluent and the complete removal of
PCP was obtained. The ageing tests showed that biochar prevents the formation of oxide film on the
ZVI particles and leaching tests confirmed the stability of ZVI on biochar matrix as very low iron leaching
was noticed.

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The polycyclic aromatic hydrocarbons (PAHs) toxicity and sorption behaviour of biochars prepared ... more The polycyclic aromatic hydrocarbons (PAHs) toxicity and sorption behaviour of biochars prepared from
pyrolysis of paper mill effluent treatment plant (ETP) sludge in temperature range 200–700 C was studied.
The sorption behaviour was found to depend on the degree of carbonization where the fractions of
carbonized and uncarbonized organic content in the biochar act as an adsorption media and partition
media, respectively. The sorption and partition fractions were quantified by isotherm separation method
and isotherm parameters were correlated with biochar properties (aromaticity, polarity, surface area,
pore volume and ash content). The risk assessment for the 16 priority EPA PAHs present in the biochar
matrix was performed and it was found that the concentrations of the PAHs in the biochar were within
the permissible limits prescribed by US EPA (except BC400 and BC500 for high molecular weight PAHs).

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The Ni–zero-valent iron magnetic biochar composites (Ni–ZVI-MBC) were synthesized from paper mill... more The Ni–zero-valent iron magnetic biochar composites (Ni–ZVI-MBC) were synthesized from paper mill
sludge and used as an adsorbent for the removal of pentachlorophenol (PCP) from the synthetic and real
paper mill effluent. The synthesized Ni–ZVI-MBC was characterized and analyzed for the stability of Ni
and ZVI particles in the biochar matrix. The Ni–ZVI-MBC involves simultaneous adsorption and
dechlorination mechanism resulting in higher PCP removal efficiency. The presence of Ni as a catalyst
in Ni–ZVI-MBC enhances the dechlorination rate and the adsorption of PCP by preventing the accumulation
of PCP in the biochar matrix. The effect of operating parameters (solution pH, Ni loading, initial PCP
concentration in the solution and temperature) on adsorption and dechlorination efficiency was studied.
The exhausted Ni–ZVI-MBCs were used for the brick formation and the bricks showed good compressive
strength and negligible heavy metal and PCP leaching.

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The risk analysis was performed to study the bioavailability and eco-toxicity of heavy metals in ... more The risk analysis was performed to study the bioavailability and eco-toxicity of heavy metals in biochar
obtained from pyrolysis of sludge of pulp and paper mill effluent treatment plant. The sludge was pyrolyzed
at different temperatures (200–700 C) and the resultant biochar were analyzed for fractionation of
heavy metals by sequential extraction procedure. It was observed that all the heavy metals get enriched
in biochar matrix after pyrolysis, but the bioavailability and eco-toxicity of the heavy metals in biochar
were significantly reduced as the mobile and bioavailable heavy metal fractions were transformed into
the relatively stable fractions. Moreover, it was observed that the leaching potential of heavy metals
decreased after pyrolysis and the best results were obtained for biochar pyrolyzed at 700 C.

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Environmental Chemistry for a Sustainable World, 2021

Magnetic adsorbents are increasingly gaining attention as a focus of research for contaminant rem... more Magnetic adsorbents are increasingly gaining attention as a focus of research for contaminant removal from water and wastewater due to their low cost, easy synthesis and separation from aqueous medium. However, the commercial applications of zero-valent iron (ZVI) and iron oxides are limited due to particle agglomeration and low oxidation stability. The agglomeration behavior of ZVI and particle oxidative stability can be enhanced by modification of magnetic adsorbents using an appropriate stabilization procedure such as surface coating or functionalization. This chapter systematically describes the recent advances in modification methods of magnetic adsorbents for contaminant removal from water and wastewater. Various modification methods including carbon stabilization, polymer coating, inorganic oxide impregnation, functionalization, and miscellaneous stabilization procedures are summarized. These stabilization procedures can enhance the adsorption capacities of magnetic adsorbents by expanding the surface area and pore volume of the adsorbents and generating new active sites and/or functional groups on the adsorbent surface. The key process parameters and relevant published data along with the results of these studies have been discussed.

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Critical Reviews in Environmental Science and Technology, 2016

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Environmental science and pollution research international, 2016

Risk assessment and technical feasibility of brick formation from exhausted paper mill sludge der... more Risk assessment and technical feasibility of brick formation from exhausted paper mill sludge derived biochar obtained after its use as an adsorbent for the treatment of effluent containing pentachlorophenol was studied. The bricks were prepared by geopolymerization mechanism in presence of sodium hydroxide, and the extent of geopolymerization was determined on the basis of crystal structure, surface functionalities, and surface morphology of the bricks. The preparation parameters (sodium hydroxide dosage, initial water and calcium carbonate content and curing temperature) were optimized and the results were analyzed in terms of compressive strength, water absorption, and abrasion index. Risk assessment of heavy metals was performed to determine the contamination level and overall hazard index of the biochar-based geopolymer bricks. Hazard quotient and hazard index were calculated to assess the overall non-carcinogenic risk posed by selected heavy metals via ingestion and dermal con...

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The Science of the total environment, 2017

Sludge based adsorbents are widely used for the removal of various pollutants from water and wast... more Sludge based adsorbents are widely used for the removal of various pollutants from water and wastewater systems and the available data is much diversified. The purpose of this review is to organize and critically review the scattered available information on the potential of use of sludge based adsorbents for the removal of various pollutants. It was observed that performance of the sludge based adsorbents varies depending on the type of pollutants, type of precursor sludge, carbonization time-temperature profile and the type of activation conditions used. The variation in pyrolysis and activation conditions found to directly affect the adsorbent properties, adsorption capacity and the mechanism of pollutant removal by sludge based adsorbents. The interaction mechanisms of pollutants with adsorbent surface found to have a detrimental effect on desorption and regeneration of the adsorbents and its recycling potential. Therefore, desorption and regeneration technique used for recycle ...

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Bioresource Technology, 2015

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Bioresource Technology, 2014

The zero-valent iron magnetic biochar composites (ZVI-MBC) were synthesized from the paper mill s... more The zero-valent iron magnetic biochar composites (ZVI-MBC) were synthesized from the paper mill sludge biochar and used for the treatment of the synthetic and real effluent containing pentachlorophenol (PCP). During the synthesis of ZVI-MBC, NaBH4 was used as the reducing agent to reduce Fe(II) to Fe(0) and cetyltrimethylammonium bromide was added as surfactant. The effect of the molar ratio of FeSO4 to NaBH4, dose of the surfactant and the ZVI to biochar ratio on the PCP removal efficiency was investigated. It was found that the ZVI-MBC combines the advantages of biochar and ZVI particles for the simultaneous adsorption and dechlorination of PCP in the effluent and the complete removal of PCP was obtained. The ageing tests showed that biochar prevents the formation of oxide film on the ZVI particles and leaching tests confirmed the stability of ZVI on biochar matrix as very low iron leaching was noticed.

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Bioresource Technology, 2014

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Journal of Clean Energy Technologies, 2014

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Children are vulnerable to heavy metal contamination through consumption of candies and chocolate... more Children are vulnerable to heavy metal contamination
through consumption of candies and chocolates.
Considering this representative samples (69) of candies
and chocolates based on cocoa, milk and sugar were
analyzed for selected heavy metals by means of flame
atomic absorption spectrometry. The average concentration
of Zn, Pb, Ni, and Cd was found to be 2.52 ± 2.49, 2.0
± 1.20, 0.84 ± 1.35, and 0.17 ± 0.22 μg/g respectively.
Results indicate that cocoa-based candies have higher
metal content than milk- or sugar-based candies. The daily
dietary intake of metals for children eating candies and
chocolates was also calculated, and results indicated
highest intake of Pb and Zn followed by Ni, Cd, and Cu.
Comparison of the current study results with other studies
around the globe shows that the heavy metal content in
candies and chocolates is lower in India than reported
elsewhere. However, to reduce the further dietary exposure

Bookmarks Related papers MentionsView impact

The zero-valent iron magnetic biochar composites (ZVI-MBC) were synthesized from the paper mill s... more The zero-valent iron magnetic biochar composites (ZVI-MBC) were synthesized from the paper mill
sludge biochar and used for the treatment of the synthetic and real effluent containing pentachlorophenol
(PCP). During the synthesis of ZVI-MBC, NaBH4 was used as the reducing agent to reduce Fe(II) to
Fe(0) and cetyltrimethylammonium bromide was added as surfactant. The effect of the molar ratio of
FeSO4 to NaBH4, dose of the surfactant and the ZVI to biochar ratio on the PCP removal efficiency was
investigated. It was found that the ZVI-MBC combines the advantages of biochar and ZVI particles for
the simultaneous adsorption and dechlorination of PCP in the effluent and the complete removal of
PCP was obtained. The ageing tests showed that biochar prevents the formation of oxide film on the
ZVI particles and leaching tests confirmed the stability of ZVI on biochar matrix as very low iron leaching
was noticed.

Bookmarks Related papers MentionsView impact

The polycyclic aromatic hydrocarbons (PAHs) toxicity and sorption behaviour of biochars prepared ... more The polycyclic aromatic hydrocarbons (PAHs) toxicity and sorption behaviour of biochars prepared from
pyrolysis of paper mill effluent treatment plant (ETP) sludge in temperature range 200–700 C was studied.
The sorption behaviour was found to depend on the degree of carbonization where the fractions of
carbonized and uncarbonized organic content in the biochar act as an adsorption media and partition
media, respectively. The sorption and partition fractions were quantified by isotherm separation method
and isotherm parameters were correlated with biochar properties (aromaticity, polarity, surface area,
pore volume and ash content). The risk assessment for the 16 priority EPA PAHs present in the biochar
matrix was performed and it was found that the concentrations of the PAHs in the biochar were within
the permissible limits prescribed by US EPA (except BC400 and BC500 for high molecular weight PAHs).

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The Ni–zero-valent iron magnetic biochar composites (Ni–ZVI-MBC) were synthesized from paper mill... more The Ni–zero-valent iron magnetic biochar composites (Ni–ZVI-MBC) were synthesized from paper mill
sludge and used as an adsorbent for the removal of pentachlorophenol (PCP) from the synthetic and real
paper mill effluent. The synthesized Ni–ZVI-MBC was characterized and analyzed for the stability of Ni
and ZVI particles in the biochar matrix. The Ni–ZVI-MBC involves simultaneous adsorption and
dechlorination mechanism resulting in higher PCP removal efficiency. The presence of Ni as a catalyst
in Ni–ZVI-MBC enhances the dechlorination rate and the adsorption of PCP by preventing the accumulation
of PCP in the biochar matrix. The effect of operating parameters (solution pH, Ni loading, initial PCP
concentration in the solution and temperature) on adsorption and dechlorination efficiency was studied.
The exhausted Ni–ZVI-MBCs were used for the brick formation and the bricks showed good compressive
strength and negligible heavy metal and PCP leaching.

Bookmarks Related papers MentionsView impact

The risk analysis was performed to study the bioavailability and eco-toxicity of heavy metals in ... more The risk analysis was performed to study the bioavailability and eco-toxicity of heavy metals in biochar
obtained from pyrolysis of sludge of pulp and paper mill effluent treatment plant. The sludge was pyrolyzed
at different temperatures (200–700 C) and the resultant biochar were analyzed for fractionation of
heavy metals by sequential extraction procedure. It was observed that all the heavy metals get enriched
in biochar matrix after pyrolysis, but the bioavailability and eco-toxicity of the heavy metals in biochar
were significantly reduced as the mobile and bioavailable heavy metal fractions were transformed into
the relatively stable fractions. Moreover, it was observed that the leaching potential of heavy metals
decreased after pyrolysis and the best results were obtained for biochar pyrolyzed at 700 C.

Bookmarks Related papers MentionsView impact