Highly efficient adsorption of cationic dye by biochar produced with Korean cabbage waste

Sewu, Divine D.,Boakye, Patrick,Woo, Seung H. Elsevier 2017 Bioresource technology Vol.224 No.-

<P><B>Abstract</B></P> <P>Biochar was produced from Korean cabbage (KC), rice straw (RS) and wood chip (WC) and the use as alternative adsorbents to activated carbon (AC) in wastewater treatment was investigated. Congo red (CR) and crystal violet (CV) were used as a model anionic and cationic dye, respectively. Initial solution pH had little effect on CR and CV adsorption onto all biochars except for AC on CR. The isotherm models and kinetic data showed that adsorption of CR and CV onto all biochars were dominantly by chemisorption. All biochars had lower adsorption capacity for CR than AC. KC showed higher Langmuir maximum adsorption capacity (1304mg/g) than AC (271.0mg/g), RS (620.3mg/g) and WC (195.6mg/g) for CV. KC may be a good alternative to conventional AC as cheap, superb and industrially viable adsorbent for removal of cationic dyes in wastewater.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Biochars were produced from rice straw, wood chip, and Korean cabbage. </LI> <LI> The adsorptive performance of the biochars was compared with activated carbon. </LI> <LI> Congo red (anionic) and crystal violet (cationic) were used as model dyes. </LI> <LI> Ash content and functional group control crystal violet adsorption onto biochars. </LI> <LI> Korean cabbage biochar adsorbs crystal violet 4.8 times more than activated carbon. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Synergistic dye adsorption by biochar from co-pyrolysis of spent mushroom substrate and <i>Saccharina japonica</i>

Sewu, Divine Damertey,Boakye, Patrick,Jung, Hwansoo,Woo, Seung Han Elsevier 2017 Bioresource technology Vol.244 No.1

<P><B>Abstract</B></P> <P>The potential of activating terrestrial biomass (spent mushroom substrate, SMS) with ash-laden marine biomass [kelp seaweed, KE] via co-pyrolysis in the field of adsorption was first investigated. KE biochar (KBC), SMS biochar (SMSBC), biochar (SK10BC) from 10%-KE added SMS, and biochar (ESBC) from KE-extract added SMS were used for the adsorption of cationic dye crystal violet (CV). ESBC had highest fixed carbon content (70.60%) and biochar yield (31.6%). SK10BC exhibited high ash content, abundant functional groups, coarser surface morphology and Langmuir maximum adsorptive capacity (610.1mg/g), which is 2.2 times higher than that of SMSBC (282.9mg/g). Biochar activated by a small amount of high ash-containing biomass such as seaweed via co-pyrolysis can serve as viable alternative adsorbent for cationic dye removal.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Biochar was produced via co-pyrolysis of spent mushroom substrate and seaweed kelp. </LI> <LI> Crystal violet (CV) was effectively removed by kelp and co-pyrolysed biochars. </LI> <LI> CV adsorption is influenced by the functional groups and ash contents. </LI> <LI> The CV adsorption synergy increased by a factor of 2.2 after co-pyrolysis. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Decolorization of cationic and anionic dye-laden wastewater by steam-activated biochar produced at an industrial-scale from spent mushroom substrate

Sewu, Divine Damertey,Jung, Hwansoo,Kim, Seung Soo,Lee, Dae Sung,Woo, Seung Han Elsevier 2019 Bioresource technology Vol.277 No.-

<P><B>Abstract</B></P> <P>The feasibility of producing biochar and its steam-activated counterpart in a large scale (1000 kg) from spent mushroom substrate (SMS) and their usage as effective environmental remediation tools to augment current SMS management strategies were explored. Steam-activated SMS biochar exhibited enhanced surface area (332 m<SUP>2</SUP>/g), pore volume (0.29 cm<SUP>3</SUP>/g), and porosity (77.1%). The effectiveness of activation was higher on the cationic dye, crystal violet (CV) by 4.1 times increase from 255 mg/g to 1057 mg/g. The biochar and its steam-activated counterpart, respectively exhibited high COD and color removal efficiencies of 49.6% and 40.1%, and 67.7 and 99.6% for CV-spiked real wastewater. Reusability studies confirmed the dominant role of chemisorption in the adsorption process. The lower production cost coupled with the superior physicochemical properties and adsorption performances rendered the biochar with/without steam activation, as a promising alternative adsorbent to serve as a green, viable and effective environmental remediation tool.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Spent mushroom substrate biochar was produced at an industrial-scale at 450 °C. </LI> <LI> Steam activation of the spent mushroom substrate biochar (SA-BC) was undertaken. </LI> <LI> BET surface area, pore volume, and porosity increased after steam activation. </LI> <LI> Biochar hydrophilicity remained unaltered after steam activation. </LI> <LI> SA-BC is among highest reported crystal violet adsorption capacities in literature. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Decolorization of triarylmethane dyes, malachite green, and crystal violet, by sewage sludge biochar: Isotherm, kinetics, and adsorption mechanism comparison

Divine Damertey Sewu,이대성,우승한,Dimitrios Kalderis 한국화학공학회 2021 Korean Journal of Chemical Engineering Vol.38 No.3

Sewage sludge biochar (SBC) was used as adsorbent to study the adsorption behavior of triarylmethane dyes, malachite green (MG; diaminotriphenylmethane), and crystal violet (CV; triaminotriphenylmethane). SBC exhibited high content (g/kg) of Al (65.8), P (64.6), Ca (57.3), and Fe (44.6). The Langmuir model showed that the affinity of MG for the surface of SBC was 22.6-times that of CV’s (KL=0.0053 l/mg); maximum Langmuir monolayer adsorption capacity of 69.5 mg/g for MG and 49.0 mg/g for CV. Similar functional groups and adsorption mechanisms like hydrogen bonding, π-π interaction, electrostatic interactions, and ion exchanges governed both MG and CV adsorption onto SBC. Both physisorption and chemisorption were involved in both dyes’ adsorption (Redlich-Peterson model: R2 > 0.900) Leachability tests showed a dependency of leached metallic ions on the type of dye employed, where ion exchange was dominated by P, Al, Ca, K for MG, and Na, K, Ca for CV. Interestingly, although minimal, the standalone contribution of biochar-free ions on MG and CV decolorization was, respectively, 13% and 7.7% (Fe), 6.7% and 2.3% (K), 2.9% and 0% (Ca), and 0% and 0.8% (Mg), which showed that some adsorption-unrelated mechanism may have also contributed to decolorization of CV and MG.

Effect of the Co-Pyrolysis of Kelp Seaweed and Spent Mushroom Substrate on the Sorption Properties of Resulting Biochars

Divine Damertey Sewu,Patrick Boakye,Seung Han Woo 대한환경공학회 2017 대한환경공학회 학술발표논문집 Vol.2017 No.11

Effect of thermal pretreatment on the extraction of potassium salt from alga <i>Saccharina japonica</i>

Boakye, Patrick,Sewu, Divine D.,Woo, Seung H. Elsevier 2018 JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS Vol.133 No.-

<P><B>Abstract</B></P> <P>Interests in conversion of macroalgae to bioenergy via thermal treatment, namely pyrolysis or combustion has increased due to their distinctive composition and high photosynthetic rates. The resulting char byproducts could serve as a trove of precious mineral resources. Thermal pretreatment was compared with direct extraction of potassium salts from alga <I>Saccharina japonica</I> using deionized water for use as food additive, agricultural or pharmaceutical applications. Biomass was pyrolysed with fixed bed reactor or combusted with muffle furnace at 300, 450, 600 °C, and extracted using deionized water in shaker at 150 rpm and 30 °C for 2 h. Overall potassium salts recovery efficiency from raw biomass (52.55 ± 2.79%) was relatively lower than from 450 °C chars from pyrolysis (75.30 ± 0.81%) and combustion (62.07 ± 0.56%). Extracts from pyrolysed char at 600 °C had highest purity of KCl which is most abundant mineral in all products. SEM-EDX and ICP-OES elemental analysis confirmed absence of heavy metals such as As, Cu, Cd and Pb in extracts. Ratios of organic to inorganic fractions in extracts from thermally pretreated samples were much lower (∼0.1) than that of raw biomass (8.42).</P> <P><B>Highlights</B></P> <P> <UL> <LI> There is increased interest in pyrolysis of macroalgae for bioenergy. </LI> <LI> <I>Saccharina japonica</I> biochar after pyrolysis contains much potassium minerals. </LI> <LI> Such minerals has wide usage in pharmaceuticals, food additive or crop fertilizer. </LI> <LI> Thermal pretreatment enhances recovery of potassium minerals such as potash (KCl). </LI> <LI> Concise and inexpensive water extraction technology with no secondary pollution. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Extraction of inorganic materials from fresh and dried alga <i>Saccharina japonica</i>

Boakye, Patrick,Sewu, Divine D.,Woo, Hee Chul,Choi, Jae Hyung,Lee, Chul Woo,Woo, Seung Han Elsevier 2017 Journal of environmental chemical engineering Vol.5 No.5

<P><B>Abstract</B></P> <P>Extraction of minerals from fresh and dried macroalgae kelp (<I>Saccharina japonica</I>) was investigated to get better biomass resource for biorefinery. At a solid to liquid ratio of 1:6 (w/v), 2h extraction, and 30°C, inorganic extraction efficiency (<I>E<SUB>inorg</SUB> </I>) and total efficiency (<I>E<SUB>tot</SUB> </I>) using water were respectively 76.88 and 50.82% for fresh biomass while those of dried biomass were 72.99 and 65.79%. For fresh biomass extraction using ethanol, <I>E<SUB>inorg</SUB> </I> (74.19%) and <I>E<SUB>tot</SUB> </I> (42.21%) were much higher than for dried biomass with 7.29% <I>E<SUB>inorg</SUB> </I> and 1.21% <I>E<SUB>tot</SUB> </I>. With 10% ethanol, <I>E<SUB>inorg</SUB> </I> were similar for both materials, however, higher ratio of inorganic to organic extraction efficiency (<I>r<SUB>E</SUB> </I>) (5.48) were obtained for fresh biomass compared to lower <I>r<SUB>E</SUB> </I> (2.02) for dried biomass. The <I>r<SUB>E</SUB> </I> for fresh biomass was higher (13.80) than that for dried biomass (1.32) using water at 1:4 solid to liquid ratio, suggesting that fresh kelp is better feedstock for bioenergy production.</P>

Rice straw-based biochar beads for the removal of radioactive strontium from aqueous solution

Jang, Jiseon,Miran, Waheed,Divine, Sewu D.,Nawaz, Mohsin,Shahzad, Asif,Woo, Seung Han,Lee, Dae Sung Elsevier 2018 Science of the Total Environment Vol.615 No.-

<P><B>Abstract</B></P> <P>Biochars from agricultural residues have recently attracted significant attention as adsorbents for purifying contaminated water and wastewater. In this study, the removal of strontium from aqueous solutions was investigated using rice straw-based biochar (RSBC) beads in both batch and continuous fixed-bed column systems. The RSBC beads had negatively charged surfaces and exhibited a large surface area (71.53m<SUP>2</SUP>/g) with high micro-porosity. The synthesized beads showed a maximum adsorption capacity of 175.95mg/g at an initial strontium concentration of 10g/L at 35°C and pH7. Furthermore, they showed a good selectivity toward strontium ions in the presence of competing ions such as Al<SUP>3+</SUP>, Mg<SUP>2+</SUP>, and K<SUP>+</SUP>. The effects of different operating conditions like flow rate and initial strontium concentration were investigated in the fixed–bed column reactor. The Thomas, Adams–Bohart, and Yoon–Nelson models were applied to the experimental data to predict the breakthrough curves using non-linear regression. Both the Thomas and the Yoon–Nelson models were appropriate for describing entire breakthrough curves under different operating conditions. Overall, RSBC beads demonstrate great potential as efficient adsorbents for the treatment of wastewater polluted with strontium in a continuous operation mode.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Rice straw-based biochar (RSBC) powder and beads were synthesized and characterized. </LI> <LI> Negatively charged RSBC beads showed a large surface area with high micro-porosity. </LI> <LI> The strontium adsorption capacity was high even in the presence of competing ions. </LI> <LI> A fixed-bed column reactor packed with RSBC beads was used for strontium removal. </LI> <LI> Both the Thomas and Yoon–Nelson models gave the best fit to the experimental data. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>