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Fulltext Effectiveness of domestic water filters in removing suspended solids, residual chlorine and coliform bacteria

Chong, Chee Kheong, Vijayakumar, G., Teoh, Leong Hooi, Siti Zubaidah, A.R., Mohamed Sapian, M., Abdul Rahim, A.

Malaysian Journal of Public Health Medicine, 2003;3(2):38-40.
MyJurnal

Water filters are being increasingly promoted and used in the home. There are many types of commercial water jilters available for domestic use but almost all of them employ a physical filter media and an activated substance. The study showed that water filters effectively removed suspended solids and residual chlorine. However, as far as removing colhform bacteria is concerned, in ZZ .5% of the cases, bacteria were in fact introduced into the water. And in 20% ofthe cases, the amount of bacteria introduced was “too numerous to count (TNTC)". Furthermore, water hlters can lose their ability to filter bacteria without losing their ability to filter suspended solids and residual chlorine. This highlights the necessity of some authorized body looking into the claims made by these water filter manufacturers and impose certain standards to ensure that at the very least, the water quality ofthe hltered water is not worse than the unfiltered water.

Matched MeSH terms: Ions
Effects of buffer properties on cyclodextrin glucanotransferase reactions and cyclodextrin production from raw sago (Cycas revoluta) starch

Kamaruddin K, Illias RM, Aziz SA, Said M, Hassan O

Biotechnol Appl Biochem, 2005 Apr;41(Pt 2):117-25.
PMID: 15202937

Results from the present study have shown that the ionic species of buffers, pH values and reaction temperature can affect the enzyme unit activities and product specificity of Toruzyme (Novo Nordisk A/S Bagsvaerd, Denmark) CGTase (cyclodextrin glucanotransferase). Applying a similar reaction environment (acetate buffer, pH 6.0; temperature, 60 degrees C), the CGTase was found to be capable of producing pre dominantly beta-cyclodextrin from either raw or gelatinized sago (Cycas revoluta) starch. Changing the buffer from acetate to phosphate reduced the yield of beta-cyclodextrin from 2.48 to 1.42 mg/ml and also affected the product specificity, where production of both alpha- and beta-cyclodextrins were more pronounced. The decrease in the production of cyclodextrins in phosphate buffer was significant at both pH 6.0 and 7.0. However, changing the buffer to Tris/HCl (pH 7.0) showed a significant increase in beta-cyclodextrin production. Increasing the ionic strength of sodium acetate and Tris/HCl buffers at pH 6.0 and 7.0 to equivalent ionic strength of phosphate buffers showed no significant effects on cyclodextrin production. Higher yield of cyclodextrins at pH 7.0 when Tris/HCl was used might be due to the binding of chloride ions at the calcium-binding sites of the CGTase, resulting in the shift of the optimum pH close to physiological environment, leading to an increase in the activities and specificity.

Matched MeSH terms: Ions; Solutions
Fulltext Effects of ion beam irradiation on Oncidium lanceanum orchids

Zaiton Ahmad, Affrida Abu Hassan, Mohd Nazir Basiran, Nurul Aliaa Idris, Tanaka, A., Shikazono, N., et al.

Journal of Nuclear and Related Technologies, 2006;2006(1):1-7.
MyJurnal

Protocorm-like bodies (PLBs) of an orchid (Oncidium lanceanum) were irradiated using 220 MeV 12 C 5+ ions, accelerated by AVF cyclotron at JAEA, Japan in 2005. Five different doses were applied to the PLBs; 0, 1.0, 2.0, 6.0 and 12.0 Gy. Following irradiation, these PLBs were maintained in cultures for germination and multiplication. Irradiation effects on growth and seedling regeneration patterns as well as molecular characteristics of the in vitro cultures were monitored and recorded. In general, average fresh weights of the irradiated PLBs increased progressively by irradiating the explants at 1.0, 2.0 and reached the maximum at 6.0 Gy. The figure however dropped when the explants were irradiated at 12 Gy. Surprisingly, although the highest average fresh weight was recorded on PLBs irradiated at 6.0 Gy, most of these PLBs were not able to regenerate into complete shoots. On average, after 4 months of irradiation, only 21 seedlings were successfully regenerated from each gram of these PLBs. The highest shoot regeneration was recorded on cultures irradiated at 2.0 Gy in which 102 seedlings were obtained from one gram of the PLBs. Some morphological changes were seen on in vitro plantlets derived from PLBs irradiated at doses of 1.0 and 2.0 Gy. Most of the regenerated seedlings have been transferred to glasshouse for further morphological selection. Molecular analysis showed the presence of DNA polymorphisms among the seedlings from different doses of irradiation.

Matched MeSH terms: Ions
Fulltext Effects on the Properties after Addition of Lithium Salt in Poly(ethylene oxide)/Poly(methyl acrylate) Blends

Abdul Halim SI, Chan CH, Kressler J

Polymers (Basel), 2020 Dec 11;12(12).
PMID: 33322501 DOI: 10.3390/polym12122963

The studies of phase behavior, dielectric relaxation, and other properties of poly(ethylene oxide) (PEO)/poly(methyl acrylate) (PMA) blends with the addition of lithium perchlorate (LiClO4) were done for different blend compositions. Samples were prepared by a solution casting technique. The binary PEO/PMA blends exhibit a single and compositional-dependent glass transition temperature (Tg), which is also true for ternary mixtures of PEO/PMA/LiClO4 when PEO was in excess with low content of salt. These may indicate miscibility of the constituents for the molten systems and amorphous domains of the systems at room temperature from the macroscopic point of view. Subsequently, the morphology of PEO/PMA blends with or without salt are correlated to the phase behavior of the systems. Phase morphology and molecular interaction of polymer chains by salt ions of the systems may rule the dielectric or electric relaxation at room temperature, which was estimated using electrochemical impedance spectroscopy (EIS). The frequency-dependent impedance spectra are of interest for the elucidation of polarization and relaxation of the charged entities for the systems. Relaxation can be noted only when a sufficient amount of salt is added into the systems.

Matched MeSH terms: Ions
Fulltext Electrochemically synthesized si nanowire arrays and thermoelectric nanostructures

Ng, Inn Khuan, Kok, Kuan Ying, Nur Ubaidah Saidin, Choo, Thye Foo

Journal of Nuclear and Related Technologies, 2012;2012(2):34-40.
MyJurnal

Thermoelectric nanostructures hold great promise for capturing and directly converting into electricity some vast amount of low-grade waste heats now being lost to the environment (e.g. from nuclear power plant, fossil fuel burning, automotives and household appliances). In this study, large-area vertically-aligned silicon nanowire (SiNW) arrays were synthesized in an aqueous solution containing AgN•i and HF on p-type Si (100) substrate by self-selective electroless etching process. The etching conditions were systematically varied in order to achieve different stages of nanowire formation. Diameters of the SiNWs obtained varied from approximately 50 to 200 nm and their lengths ranged from several to a few tens of um. Te/Bi2Tex.Si thermoelectric core-shell nanostructures were subsequently obtained via galvanic displacement of SiNWs in acidic HF electrolytes containing HTe02+ and 139' /HTe02+ ions. The reactions were basically a nano-electrochemical process due to the difference in redox potentials between the materials. The surface-modified SiNWs of core-shell structures had roughened surface morphologies and, therefore, higher surface-to-bulk ratios compared to unmodified SiNWs. They have potential applications in sensors, photovoltaic and thermoelectric nanodevices. Growth study on the SiNWs and core-shell nanostructures produced is presented using various microscopy, diffraction and probe-based techniques for microstructural, morphological and chemical characterizations.

Matched MeSH terms: Ions
Enhanced Catalytic Activity, Facile Synthesis and Characterization Studies of Spinel Mn-Co Aluminate Nano-Catalysts

Bhavani P, Manikandan A, Jaganathan SK, Shankar S, Antony SA

J Nanosci Nanotechnol, 2018 Feb 01;18(2):1388-1395.
PMID: 29448597 DOI: 10.1166/jnn.2018.14112

Undoped and Mn2+ doped CoAl2O4 (MnxCo1-xAl2O4; x = 0.0 to 1.0) spinel nanoparticles were successfully synthesized by a microwave heating method using glycine as the fuel. X-ray powder diffraction (XRD) was confirmed the cubic spinel structure. The average crystallite size of the samples was found to be in the range of 16.46 nm to 20.25 nm calculated by Scherrer's formula. The nano-sized particle-like morphology of the samples was confirmed by high resolution scanning electron microscopy (HR-SEM) and transmission electron microscopy (HR-TEM) analysis. Energy dispersive X-ray (EDX) results showed the pure form of spinel aluminate structure. The band gap energy (Eg) of pure CoAl2O4 was estimated to be 3.68 eV from UV-Visible diffuse reflectance spectroscopy (DRS), and the Eg values increased with increase of Mn2+ ions, due to the smaller grain size. The magnetic hysteresis (M-H) loop showed the superparamagnetic nature, and the magnetization and coercivity values increased with increasing Mn2+ ions, which was confirmed by vibrating sample magnetometer (VSM). All compositions of the nano-catalysts were tested as catalyst successfully for the conversion of benzyl alcohol into benzaldehyde and observed good catalytic activity.

Matched MeSH terms: Ions
Enhancement of fluoride release from glass ionomer cement following a coating of silver fluoride

Ariffin Z, Ngo H, McIntyre J

Aust Dent J, 2006 Dec;51(4):328-32.
PMID: 17256308

BACKGROUND: This study investigated the extent to which a coating of 10% silver fluoride (AgF) on discs of glass jonomer cements (GIGs) would enhance the release of fluoride ion into eluting solutions at varying pH.
MATERIALS AND METHODS: Forty discs each of Fuji LX, Fuji VII and of Vitrebond were prepared in a plastic mould. Twenty discs of each material were coated for 30 seconds with a 10% solution of AgF. Five discs each of coated and uncoated material were placed individually in 4m1 of differing eluant solutions. The eluant solutions comprised deionized distilled water (DDW) and three separate acetate buffered solutions at pH 7, pH 5 and pH 3. After 30 minutes the discs were removed and placed in five vials containing 4m1 of the various solutions for a further 30 minutes. This was repeated for further intervals of time up to 216 hours, and all eluant solutions were stored. Fluoride concentrations in the eluant solutions were estimated using a fluoride specific electrode, with TISAB IV as a metal ion complexing and ionic concentration adjustment agent. Cumulative fluoride release patterns were determined from the incremental data.
RESULTS: The coating of AgF greatly enhanced the level of fluoride ion release from all materials tested. Of the uncoated samples, Vitrehond released the greater concentrations of fluoride ion, followed by Fuji VII. However, cumulative levels of fluoride released from coated samples of the GICs almost matched those from coated Vitrebond.
CONCLUSIONS: It was concluded that a coating of 10% AgF on GICs and a resin modified GIC greatly enhanced the concentration of fluoride released from these materials. This finding might be applied to improving protection against recurrent caries, particularly in high caries risk patients, and in the atraumatic restorative technique (ART) of restoration placement.

Matched MeSH terms: Ions
Enhancing the Efficiency of a Dye-Sensitized Solar Cell Based on a Metal Oxide Nanocomposite Gel Polymer Electrolyte

Saidi NM, Omar FS, Numan A, Apperley DC, Algaradah MM, Kasi R, et al.

ACS Appl Mater Interfaces, 2019 Aug 21;11(33):30185-30196.
PMID: 31347822 DOI: 10.1021/acsami.9b07062

To overcome the critical limitations of liquid-electrolyte-based dye-sensitized solar cells, quasi-solid-state electrolytes have been explored as a means of addressing long-term device stability, albeit with comparatively low ionic conductivities and device performances. Although metal oxide additives have been shown to augment ionic conductivity, their propensity to aggregate into large crystalline particles upon high-heat annealing hinders their full potential in quasi-solid-state electrolytes. In this work, sonochemical processing has been successfully applied to generate fine Co3O4 nanoparticles that are highly dispersible in a PAN:P(VP-co-VAc) polymer-blended gel electrolyte, even after calcination. An optimized nanocomposite gel polymer electrolyte containing 3 wt % sonicated Co3O4 nanoparticles (PVVA-3) delivers the highest ionic conductivity (4.62 × 10-3 S cm-1) of the series. This property is accompanied by a 51% enhancement in the apparent diffusion coefficient of triiodide versus both unmodified and unsonicated electrolyte samples. The dye-sensitized solar cell based on PVVA-3 displays a power conversion efficiency of 6.46% under AM1.5 G, 100 mW cm-2. By identifying the optimal loading of sonochemically processed nanoparticles, we are able to generate a homogenous extended particle network that effectively mobilizes redox-active species through a highly amorphous host matrix. This effect is manifested in a selective 51% enhancement in photocurrent density (JSC = 16.2 mA cm-2) and a lowered barrier to N719 dye regeneration (RCT = 193 Ω) versus an unmodified solar cell. To the best of our knowledge, this work represents the highest known efficiency to date for dye-sensitized solar cells based on a sonicated Co3O4-modified gel polymer electrolyte. Sonochemical processing, when applied in this manner, has the potential to make meaningful contributions toward the ongoing mission to achieve the widespread exploitation of stable and low-cost dye-sensitized solar cells.

Matched MeSH terms: Ions
Equilibrium, kinetic and mechanism studies of Cu(II) and Cd(II) ions adsorption by modified chitosan beads

Sutirman ZA, Sanagi MM, Abd Karim KJ, Wan Ibrahim WA, Jume BH

Int J Biol Macromol, 2018 Sep;116:255-263.
PMID: 29746971 DOI: 10.1016/j.ijbiomac.2018.05.031

In this study, the Cu(II) and Cd(II) ions removal behavior of crosslinked chitosan beads grafted poly(methacrylamide) (abbreviated as crosslinked chitosan-g-PMAm) from single metal ion solutions was investigated. The modified chitosan beads presented a remarkable improvement in acid resistance. The batch experiments demonstrated that pH of solution played a significant role in adsorption. It was found that the adsorption of Cu(II) and Cd(II) were optimum at pH 4 and pH 5, respectively. The maximum adsorption capacities for Cu(II) and Cd(II) based on Langmuir equation were 140.9 mg g-1 and 178.6 mg g-1, respectively. Pseudo-second order gave a better fit for adsorption data with respect to linearity coefficients than pseudo-first order suggesting that chemisorption or electron transfer is the dominant mechanism of the metal ions onto crosslinked chitosan-g-PMAm. In addition, X-ray photoelectron spectroscopy (XPS) investigations revealed that adsorption of both metal ions took place on the surfaces of crosslinked chitosan-g-PMAm by chelation through CNH2, CO and CO groups. Overall, the modified chitosan has proved a promising adsorbent for removal of metal ions.

Matched MeSH terms: Ions/chemistry*
Evaluation of groundwater quality and its suitability for drinking and agricultural use in Thanjavur city, Tamil Nadu, India

Nagarajan R, Rajmohan N, Mahendran U, Senthamilkumar S

Environ Monit Assess, 2010 Dec;171(1-4):289-308.
PMID: 20072811 DOI: 10.1007/s10661-009-1279-9

As groundwater is a vital source of water for domestic and agricultural activities in Thanjavur city due to lack of surface water resources, groundwater quality and its suitability for drinking and agricultural usage were evaluated. In this study, 102 groundwater samples were collected from dug wells and bore wells during March 2008 and analyzed for pH, electrical conductivity, temperature, major ions, and nitrate. Results suggest that, in 90% of groundwater samples, sodium and chloride are predominant cation and anion, respectively, and NaCl and CaMgCl are major water types in the study area. The groundwater quality in the study site is impaired by surface contamination sources, mineral dissolution, ion exchange, and evaporation. Nitrate, chloride, and sulfate concentrations strongly express the impact of surface contamination sources such as agricultural and domestic activities, on groundwater quality, and 13% of samples have elevated nitrate content (>45 mg/l as NO(3)). PHREEQC code and Gibbs plots were employed to evaluate the contribution of mineral dissolution and suggest that mineral dissolution, especially carbonate minerals, regulates water chemistry. Groundwater suitability for drinking usage was evaluated by the World Health Organization and Indian standards and suggests that 34% of samples are not suitable for drinking. Integrated groundwater suitability map for drinking purposes was created using drinking water standards based on a concept that if the groundwater sample exceeds any one of the standards, it is not suitable for drinking. This map illustrates that wells in zones 1, 2, 3, and 4 are not fit for drinking purpose. Likewise, irrigational suitability of groundwater in the study region was evaluated, and results suggest that 20% samples are not fit for irrigation. Groundwater suitability map for irrigation was also produced based on salinity and sodium hazards and denotes that wells mostly situated in zones 2 and 3 are not suitable for irrigation. Both integrated suitability maps for drinking and irrigation usage provide overall scenario about the groundwater quality in the study area. Finally, the study concluded that groundwater quality is impaired by man-made activities, and proper management plan is necessary to protect valuable groundwater resources in Thanjavur city.

Matched MeSH terms: Ions/chemistry
Evaluation of membrane fouling at elevated temperature impacted by algal organic matter

Ng YS, Ragupathy S, Shau Hwai AT, Khoo KS, Chieh Chan DJ

Chemosphere, 2023 Jan;310:136790.
PMID: 36220430 DOI: 10.1016/j.chemosphere.2022.136790

Membrane distillation (MD) is a thermally driven technology applied in desalination and water reuse with utilisation of sustainable energy. However, algal organic matter (AOM) could foul membrane critically and plague MD's long-term operational stability. In this study, the soluble extracellular polymeric substance (sEPS) and intracellular organic matter with bound extracellular polymeric substance (IOM + bEPS) of two algal species (Amphora coffeaeformis and Navicula incerta) were exposed to 60 °C, 70 °C and 80 °C for 8 h with polypropylene hydrophobic membrane, simulating heated AOMs contacted with membrane inside MD unit, to study the temperature effect on membrane fouling. The dissolved carbohydrate and protein in the sEPS and IOM + bEPS samples generally increased after being heated. Heating caused cell lysis and the release and dissolution of carbohydrate and protein from sEPS, IOM and bEPS into water. As heating temperature increased, the carbohydrate release from the AOM usually increased. The contact angle of membrane contacted with sEPS and IOM + bEPS reduced significantly after heat treatment. The reduction in IOM + bEPS was larger than sEPS, in line with SEM analysis, indicating membrane surfaces and pores with IOM + bEPS fouled more severely than sEPS. It is due to higher hydrophobicity in IOM + bEPS causing adherence to membrane and presence of amphiphiles. High protein, lipid, and saturated fats proportions also cause severe fouling. SEM-EDX analysis indicated presence of O, Na, Cl and Mg elements, pointing to carbohydrate and lipids, and salt trapped in foulants. AOM heating and composition had direct effect to the membrane integrity, dictating severity of fouling in MD operations.

Matched MeSH terms: Ions
Fulltext Evaluation of yield and groundwater quality for selected wells in Malaysia

Mohammed, Thamer Ahmed, Abdul Halim Ghazali

Pertanika Journal of Science & Technology, 2009;17(1):-.
MyJurnal

In Malaysia, the use of groundwater can help to meet the increasing water demand. The utilization of the aquifers is currently contributing in water supplies, particularly for the northern states. In this study, quantitative and qualitative assessments were carried out for the groundwater exploitation in the states of Kelantan, Melaka, Terengganu and Perak. The relevant data was acquired from the Department of Mineral and Geoscience, Malaysia. The quantitative assessment mainly included the determination of the use to yield ratio (UTY). The formula was proposed to determine the UTY ratio for aquifers in Malaysia. The proposed formula was applied to determine the maximum UTY ratios for the aquifers located in the states of Kelantan, Melaka, and Terengganu, and were found to be 4.2, 5.2 and 0.6, respectively. This indicated that exploitation of groundwater was beyond the safe limit in the states of Kelantan and Melaka. The qualitative assessment showed that the groundwater is slightly acidic. In addition, the concentrations of iron and manganese were found to be higher than the allowable limits, but the chloride concentration was found within the allowable limit.

Matched MeSH terms: Ions
Evidence for Top Quark Production in Nucleus-Nucleus Collisions

Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Bergauer T, Dragicevic M, et al.

Phys Rev Lett, 2020 Nov 27;125(22):222001.
PMID: 33315428 DOI: 10.1103/PhysRevLett.125.222001

Ultrarelativistic heavy ion collisions recreate in the laboratory the thermodynamical conditions prevailing in the early universe up to 10^{-6} sec, thereby allowing the study of the quark-gluon plasma (QGP), a state of quantum chromodynamics (QCD) matter with deconfined partons. The top quark, the heaviest elementary particle known, is accessible in nucleus-nucleus collisions at the CERN LHC, and constitutes a novel probe of the QGP. Here, we report the first evidence for the production of top quarks in nucleus-nucleus collisions, using lead-lead collision data at a nucleon-nucleon center-of-mass energy of 5.02 TeV recorded by the CMS experiment. Two methods are used to measure the cross section for top quark pair production (σ_{tt[over ¯]}) via the selection of charged leptons (electrons or muons) and bottom quarks. One method relies on the leptonic information alone, and the second one exploits, in addition, the presence of bottom quarks. The measured cross sections, σ_{tt[over ¯]}=2.54_{-0.74}^{+0.84} and 2.03_{-0.64}^{+0.71} μb, respectively, are compatible with expectations from scaled proton-proton data and QCD predictions.

Matched MeSH terms: Heavy Ions
Experimental and first-principles DFT studies on the band gap behaviours of microsized and nanosized Zn(1-x)MnxO materials

Kasim MF, Darman AKAB, Yaakob MK, Badar N, Kamarulzaman N

Phys Chem Chem Phys, 2019 Sep 11;21(35):19126-19146.
PMID: 31432825 DOI: 10.1039/c9cp01664c

In this study, nano- and microsized zinc oxide (ZnO) materials were doped with different manganese (Mn) contents (1-5 mol%) via a simple sol-gel method. The structural, morphological, optical and chemical environments of the materials were investigated using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), UV-visible spectroscopy (UV-vis) and X-ray photoelectron spectroscopy (XPS). XRD results revealed that all synthesised materials were pure and single phased with a hexagonal wurtzite structure of ZnO. However, at a low annealing temperature, a nanorod-like shape can be obtained for all Zn(1-x)MnxO materials. In addition, EDX spectra confirmed the presence of Mn in the ZnO lattice and the atomic percentage was nearly equal to the calculated stoichiometry. UV-vis spectroscopy further revealed that materials in nano size exhibited band gap widening with an increase of the Mn content in the ZnO lattice. In contrast, micron state materials exhibited band gap narrowing with increasing Mn content up to 3% and then begin to widen when Mn > 3%. This is because the band gaps of these materials are affected by the dimensions of the crystals and the Mn content in the materials. Furthermore, XPS results revealed the existence of multiple states of Mn in all synthesised materials. By combining the information obtained from UV-vis and the XPS valence band, shifting in the valence band maximum (VBM) and conduction band minimum (CBM) was observed. Based on XPS results, the calculation of density functional theory studies revealed that the presence of Mn2+, Mn3+, and Mn4+ ions in the materials influences the band gap changes. It was also revealed that the nanosized Zn0.99Mn0.01O exhibited a higher photocatalytic activity than the other samples for degrading methylene blue (MB) dyes, owing to its smallest crystallite size.

Matched MeSH terms: Ions
Fulltext Expression and characterization of thermotolerant lipase with broad pH profiles isolated from an Antarctic Pseudomonas sp strain AMS3

Latip W, Raja Abd Rahman RNZ, Chor Leow AT, Mohd Shariff F, Mohamad Ali MS

PeerJ, 2016;4:e2420.
PMID: 27781152 DOI: 10.7717/peerj.2420

A gene encoding a thermotolerant lipase with broad pH was isolated from an Antarctic Pseudomonas strain AMS3. The recombinant lipase AMS3 was purified by single-step purification using affinity chromatography, yielding a purification fold of approximately 1.52 and a recovery of 50%. The molecular weight was approximately ∼60 kDa including the strep and affinity tags. Interestingly, the purified Antarctic AMS3 lipase exhibited broad temperature profile from 10-70 °C and stable over a broad pH range from 5.0 to pH 10.0. Various mono and divalent metal ions increased the activity of the AMS3 lipase, but Ni(2+) decreased its activity. The purified lipase exhibited the highest activity in the presence of sunflower oil. In addition, the enzyme activity in 25% v/v solvents at 50 °C particularly to n-hexane, DMSO and methanol could be useful for catalysis reaction in organic solvent and at broad temperature.

Matched MeSH terms: Antarctic Regions; Ions
Extraction and characterization of lignin from oil palm biomass via ionic liquid dissolution and non-toxic aluminium potassium sulfate dodecahydrate precipitation processes

Mohtar SS, Tengku Malim Busu TN, Md Noor AM, Shaari N, Yusoff NA, Bustam Khalil MA, et al.

Bioresour Technol, 2015 Sep;192:212-8.
PMID: 26038325 DOI: 10.1016/j.biortech.2015.05.029

The objective of this study is to extract and characterize lignin from oil palm biomass (OPB) by dissolution in 1-butyl-3-methylimidazolium chloride ([bmim][Cl]), followed by the lignin extraction through the CO2 gas purging prior to addition of aluminum potassium sulfate dodecahydrate (AlK(SO4)2 · 12H2O). The lignin yield, Y(L) (%wt.) was found to be dependent of the types of OPB observed for all precipitation methods used. The lignin recovery, RL (%wt.) obtained from CO2-AlK(SO4)2 · 12H2O precipitation was, however dependent on the types of OPB, which contradicted to that of the acidified H2SO4 and HCl solutions of pH 0.7 and 2 precipitations. Only about 54% of lignin was recovered from the OPB. The FTIR results indicate that the monodispersed lignin was successfully extracted from the OPT, OPF and OPEFB having a molecular weight (MW) of 1331, 1263 and 1473 g/mol, and degradation temperature of 215, 207.5 and 272 °C, respectively.

Matched MeSH terms: Ions/chemistry; Solutions/chemistry
FT-IR studies on interactions among components in hexanoyl chitosan-based polymer electrolytes

Winie T, Arof AK

Spectrochim Acta A Mol Biomol Spectrosc, 2006 Mar 1;63(3):677-84.
PMID: 16157506

Fourier transform infrared (FT-IR) spectroscopic studies have been undertaken to investigate the interactions among components in a system of hexanoyl chitosan-lithium trifluoromethanesulfonate (LiCF(3)SO(3))-diethyl carbonate (DEC)/ethylene carbonate (EC). LiCF(3)SO(3) interacts with the hexanoyl chitosan to form a hexanoyl chitosan-salt complex that results in the shifting of the N(COR)(2), CONHR and OCOR bands to lower wavenumbers. Interactions between EC and DEC with LiCF(3)SO(3) has been noted and discussed. Evidence of interaction between EC and DEC has been obtained experimentally. Studies on polymer-plasticizer spectra suggested that there is no interaction between the polymer host and plasticizers. Competition between plasticizer and polymer on associating with Li(+) ions was observed from the spectral data for gel polymer electrolytes. The obtained spectroscopic data has been correlated with the conductivity performance of hexanoyl chitosan-based polymer electrolytes.

Matched MeSH terms: Ions
Fabrication of chitosan@activated carbon composites in EmimAc for Cd(II) adsorption from aqueous solution: Experimental, optimization and DFT study

Saheed IO, Yusof ENM, Oh WD, Hanafiah MAKM, Suah FBM

Int J Biol Macromol, 2023 Jul 01;242(Pt 2):124798.
PMID: 37178882 DOI: 10.1016/j.ijbiomac.2023.124798

Adsorption efficiency of a duo-material blend featuring the fabrication of modified chitosan adsorbents (powder (C-emimAc), bead (CB-emimAc) and sponge (CS-emimAc)) for the removal of Cd(II) from aqueous solution was investigated. The chitosan@activated carbon (Ch/AC) blend was developed in a green ionic solvent, 1-ethyl-3-methyl imidazolium acetate (EmimAc) and its characteristics was examined using FTIR, SEM, EDX, BET and TGA. The possible mechanism of interaction between the composites and Cd(II) was also predicted using the density functional theory (DFT) analysis. The interactions of various blend forms (C-emimAc, CB-emimAc and CS-emimAc) with Cd(II) gave better adsorption at pH 6. The composites also present excellent chemical stability in both acidic and basic conditions. The monolayer adsorption capacities obtained (under the condition 20 mg/L [Cd], adsorbent dosage 5 mg, contact time 1 h) for the CB-emimAc (84.75 mg/g) > C-emimAc (72.99 mg/g) > CS-emimAc (55.25 mg/g), as this was supported by their order of increasing BET surface area (CB-emimAc (120.1 m2/g) > C-emimAc (67.4 m2/g) > CS-emimAc (35.3 m2/g)). The feasible adsorption interactions between Cd(II) and Ch/AC occurs through the O-H and N-H groups of the composites, as supported by DFT analysis in which an electrostatic interactions was predicted as the dominant force. The interaction energy (-1309.35 eV) calculated via DFT shows that the Ch/AC with amino (-NH) and hydroxyl (-OH) groups are more effective with four significant electrostatic interactions with the Cd(II) ion. The various form of Ch/AC composites developed in EmimAc possess good adsorption capacity and stability for the adsorption Cd(II).

Matched MeSH terms: Ions
Fulltext Filler-Modified Castor Oil-Based Polyurethane Foam for the Removal of Aqueous Heavy Metals Detected Using Laser-Induced Breakdown Spectroscopy (LIBS) Technique

Iqhrammullah M, Marlina, Hedwig R, Karnadi I, Kurniawan KH, Olaiya NG, et al.

Polymers (Basel), 2020 Apr 13;12(4).
PMID: 32294999 DOI: 10.3390/polym12040903

The use of polymeric material in heavy metal removal from wastewater is trending. Heavy metal removal from wastewater of the industrial process is of utmost importance in green/sustainable manufacturing. Production of absorbent materials from a natural source for industrial wastewater has been on the increase. In this research, polyurethane foam (PUF), an adsorbent used by industries to adsorb heavy metal from wastewater, was prepared from a renewable source. Castor oil-based polyurethane foam (COPUF) was produced and modified for improved adsorption performance using fillers, analyzed with laser-induced breakdown spectroscopy (LIBS). The fillers (zeolite, bentonite, and activated carbon) were added to the COPUF matrix allowing the modification on its surface morphology and charge. The materials were characterized using Fourier-transform infrared (FTIR), scanning electron microscopy (SEM), and thermal gravimetry analysis (TGA), while their adsorption performance was studied by comparing the LIBS spectra. The bentonite-modified COPUF (B/COPUF) gave the highest value of the normalized Pb I (405.7 nm) line intensity (2.3), followed by zeolite-modified COPUF (Z/COPUF) (1.9), and activated carbon-modified COPUF (AC/COPUF) (0.2), which indicates the adsorption performance of Pb2+ on the respective materials. The heavy metal ions' adsorption on the B/COPUF dominantly resulted from the electrostatic attraction. This study demonstrated the potential use of B/COPUF in adsorption and LIBS quantitative analysis of aqueous heavy metal ions.

Matched MeSH terms: Ions
Flocculation of Chlorella vulgaris by shell waste-derived bioflocculants for biodiesel production: Process optimization, characterization and kinetic studies

Suparmaniam U, Lam MK, Uemura Y, Shuit SH, Lim JW, Show PL, et al.

Sci Total Environ, 2020 Feb 01;702:134995.
PMID: 31710849 DOI: 10.1016/j.scitotenv.2019.134995

Flocculants are foreign particles that aggregate suspended microalgae cells and due to cost factor and toxicity, harvesting of microalgae biomass has shifted towards the use of bioflocculants. In this study, mild acid-extracted bioflocculants from waste chicken's eggshell and clam shell were used to harvest Chlorella vulgaris that was cultivated using chicken compost as nutrient source. It was found that a maximum of 99% flocculation efficiency can be attained at pH medium of 9.8 using 60 mg/L of hydrochloric acid-extracted chicken's eggshell bioflocculant at 50 °C of reaction temperature. On the other hand, 80 mg/L of hydrochloric acid-extracted clam shell bioflocculant was sufficient to recover C. vulgaris biomass at pH 9.8 and optimum temperature of 40 °C. The bioflocculants and bioflocs were characterized using microscopic, zeta potential, XRD, AAS and FT-IR analysis. The result revealed that calcium ions in the bioflocculants are the main contributor towards the flocculation of C. vulgaris, employing charge neutralization and sweeping as possible flocculation mechanisms. The kinetic parameters were best fitted pseudo-second order which resulted in R2 of 0.99 under optimal flocculation temperature. The results herein, disclosed the applicability of shell waste-derived bioflocculants for up-scaled microalgae harvesting for biodiesel production.

Matched MeSH terms: Ions

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