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>

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>

Effect of water washing pretreatment on property and adsorption capacity of macroalgae-derived biochar

Boakye, Patrick,Tran, Hai Nguyen,Lee, Dae Sung,Woo, Seung Han Elsevier 2019 Journal of environmental management Vol.233 No.-

<P><B>Abstract</B></P> <P>The effects of water washing pretreatment process on the property and adsorption capacity of biochar were investigated at different biochar/water ratios from 1:5 to 1:100 (w/v). <I>Saccharina japonica</I> macroalgae-derived biochars (B300, B450, and B600) were prepared at 300 °C, 450 °C, and 600 °C, respectively. The optimal biochar/water ratio was obtained at 1:10. The results indicated that the washing pretreatment can contribute to dramatically increasing the specific surface area of biochars, but slightly increasing their porosity. The washed biochars were carbonaceous microporous materials (67–80% micropore volume), with their specific surface area and porosity being B600 (543 m<SUP>2</SUP>/g and 86%), B450 (521 m<SUP>2</SUP>/g and 75%), and B300 (188 m<SUP>2</SUP>/g and 80%), respectively. The unwashed biochars exhibited a significantly higher ash content (59%–65%) than washed biochars (26%–35%). Equilibrium adsorption study demonstrated that the Langmuir maximum adsorption capacity (<I>Q</I> <SUP>o</SUP> <SUB>max</SUB>) of crystal violet cationic dye decreased in the following order: unwashed-B450 (1719 mg/g) > washed-B450 (1277 mg/g) > commercial activated carbon (492 mg/g). The washing pretreatment can remove solute-inorganic minerals to prevent their release from biochar during the dye adsorption. The washed biochar with its excellent adsorption capacity can serve as a highly sustainable and industrially viable adsorbent for the removal of cationic dyes from waste bodies.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Biochar from <I>Saccharina japonica</I>-derived sulfated macroalgae at 300, 450, and 600 °C. </LI> <LI> Washing pretreatment on biochar's property and cationic dye adsorption capacity. </LI> <LI> <I>S</I> <SUB>BET</SUB>-biosorbent (0.03–0.21); chars: unwashed (1.36–266), washed (188–543); CAC (688). </LI> <LI> Langmuir <I>Q</I> <SUP>o</SUP> <SUB>max</SUB>: CAC < biosorbent < washed biochars < unwashed biochars. </LI> <LI> Washing pretreatment prevents minerals release from chars during dye adsorption. </LI> </UL> </P>

Superhydrophobic and Superoleophilic Cu Meshes possessing Filter and Catalysis Functions for Oil/Water Separation and Pollutant Purification

Stephen Boakye Ansah,이하진,최원산 한국고분자학회 2015 한국고분자학회 학술대회 연구논문 초록집 Vol.2015 No.4

The Cell Viability on Kelp and Fir Biochar and the Effect on the Field Cultivation of Corn

Patrick Boakye,Chul Woo Lee,Won Mook Lee,Seung Han Woo 한국청정기술학회 2016 청정기술 Vol.22 No.1

Field cultivation of corn and microbial cell viability tests using Pseudomonas putida K-5 were performed to assess the toxic effect of kelp seaweed biochar (KBC) and fir wood biochar (FBC) produced by pyrolysis. After 63 days growth, FBC increased corn growth by 4.9% without fertilizer and by 7.6% with fertilizer, while KBC decreased it by 20.2% without fertilizer and by 27.9% with fertilizer. Physico-chemical characterization of the biochars such as ICP, CHON, and proximate analyses showed that KBC contained large amount of metals and ashes which could be responsible for its inhibition to corn growth. Upon exposure of K-5 cells for 1 h to biochar extracts, the cell viability in KBC extracts was 48.2% and quite lower than that (78.6%) in FBC. Washed KBC biochar with water at 1:10 w/v % increased the cell viability to 54.0%. The results indicated that seaweed biochar may be careful to be used for plant growing additives due to its high concentrations of metals and ashes. This toxic effect could be reduced by proper washing method with water.

“Post-Decompressive Neuropathy”: New-Onset Post-Laminectomy Lower Extremity Neuropathic Pain Different from the Preoperative Complaint

Lorraine A. T. Boakye,Mitchell S. Fourman,Nicholas T. Spina,Dann Laudermilch,Joon Y. Lee 대한척추외과학회 2018 Asian Spine Journal Vol.12 No.6

Study Design: Level III retrospective cross-sectional study. Purpose: To define and characterize the presentation, symptom duration, and patient/surgical risk factors associated with ‘postdecompressive neuropathy (PDN).’ Overview of Literature: PDN is characterized by lower extremity radicular pain that is ‘different’ from pre-surgical radiculopathy or claudication pain. Although it is a common constellation of postoperative symptoms, PDN is incompletely characterized and poorly understood. We hypothesize that PDN is caused by an intraoperative neuropraxic event and may develop early (within 30 days following the procedure) or late (after 30 days following the procedure) within the postoperative period. Methods: Patients who consented to undergo lumbar laminectomy with or without an instrumented fusion for degenerative lumbar spine disease were followed up prospectively from July 2013 to December 2014. Relevant data were extracted from the charts of the eligible patients. Patient demographics and surgical factors were identified. Patients completed postoperative questionnaires 3 weeks, 3 months, 6 months, and 1 year postoperatively. Questions were designed to characterize the postoperative pain that differed from preoperative pain. A diagnosis of PDN was established if the patient exhibited the following characteristics: pain different from preoperative pain, leg pain worse than back pain, a non-dermatomal pain pattern, and nocturnal pain that often disrupted sleep. A Visual Analog Scale was used to monitor the pain, and patients documented the effectiveness of the prescribed pain management modalities. Patients for whom more than one follow-up survey was missed were excluded from analysis. Results: Of the 164 eligible patients, 118 (72.0%) completed at least one follow-up survey at each time interval. Of these eligible patients, 91 (77.1%) described symptoms consistent with PDN. Additionally, 75 patients (82.4%) described early- onset symptoms, whereas 16 reported symptoms consistent with late-onset PDN. Significantly more female patients reported PDN symptoms (87% vs. 69%, p =0.03). Patients with both early and late development of PDN described their leg pain as an intermittent, constant, burning, sharp/stabbing, or dull ache. Early PDN was categorized more commonly as a dull ache than late-onset PDN (60% vs. 31%, p =0.052); however, the difference did not reach statistical significance. Opioids were significantly more effective for patients with early-onset PDN than for those with late-onset PDN (85% vs. 44%, p =0.001). Gabapentin was most commonly prescribed to patients who cited no resolution of symptoms (70% vs. 31%, p =0.003). Time to symptom resolution ranged from within 1 month to 1 year. Patients’ symptoms were considered unresolved if symptoms persisted for more than 1 year postoperatively. In total, 81% of the patients with earlyonset PDN reported complete symptom resolution 1 year postoperatively compared with 63% of patients with late-onset PDN (p =0.11). Conclusions: PDN is a discrete postoperative pain phenomenon that occurred in 77% of the patients who underwent lumbar laminectomy with or without instrumented fusion. Attention must be paid to the constellation and natural history of symptoms unique to PDN to effectively manage a self-limiting postoperative issue.

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>

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

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>

3D Heat Transfer Model Simulation with Anomaly Characteristics

Nguyen, Quynh Nhu(응웬퀸뉴),Boakye, Kingsley Asare(보아체 킹슬리 아사레),Lim, Tae-Hoon(임태훈),Park, Gyung-Tae(박경태),Ko, Beom-Jun(고범준),Lee, Changho(이창호) 한국지반신소재학회 2023 한국지반신소재학회 학술발표회 Vol.2023 No.11