Maximum Iodine Research Articles

Synthesis and structural characterization of new group 12 metal ions coordination polymers built on sulfur‐based ligand and probing their high iodine adsorption efficiency in micro and bulk forms

In this work, we have prepared two new sulfur CPs with group 12 transition metals, namely,[Zn (NCS)Cl(μ2‐L)]n(1)and[Hg (SCN)2(μ2‐L)]n(3).[Cd (NCS)Cl(μ2‐L)]n(2), which is isostructural with1, was synthesized for a comparison from our published work. These compounds have been characterized by FT‐IR, UV–Vis, powder X‐ray diffraction (PXRD), elemental analysis (CHNS), scanning electron microscopy (Fe‐SEM), TGA, BET, and single‐crystal X‐ray analysis for1and3. In the structure of all polymers, the bbit ligand [L = bbit = 1,1‐bis(3‐methyl‐4‐imidazoline‐2‐thion)butane] is bridged between metal centers by the anti‐anti‐anti conformation to form an infinite 1D zigzag chain. The considered polymers were used for the removal of a substantial amount of I2from cyclohexane solution. Despite the nonporous and low dimensional frameworks of title polymers, their maximum iodine adsorption capacities were notable and in order of 817.68, 906.48, and 911.08 mg/g for polymers1–3, respectively, with an extraordinary stability toward iodine. The capacity of micro‐sized structures was almost double as compared with their bulk ones.

In-situ growth of zeolitic imidazolate framework-8 on polypyrrole nanotubes for highly efficient and reversible capture of radioiodine

Effective capture of radioiodine derived from nuclear reactor accidents and spent fuel reprocessing is of critical significance for the sustainable development of nuclear energy. Herein, we reported the successful synthesis of core-shell PPyNT@ZIF-8 (PZ) nanocomposites with ZIF-8 nanocrystals decorating polypyrrole nanotubes (PPyNT) through a facile, self-assembly procedure. Taking advantage of abundant electron-rich nitrogen atoms of polypyrrole skeleton as well as the high specific surface areas and porosities, these PZ nanocomposites had potential application in radioiodine capture. The maximum uptake capacity of as-synthesized PZ nanocomposites for vapor iodine reached up to 603.8 wt% within 5 h. Additionally, PZ nanocomposites exhibited excellent recycle abilities, as the uptake capacity of PZ-3 still remained 381.7 wt% (63.2% of the initial capacity) after five capture-release cycles. In iodine/cyclohexane solution, the maximum iodine adsorption capacity was 837.9 mg g-1 and all of the loaded iodine could be effectively released in ethanol solution. The excellent iodine capture performance was primarily attributed to the strong affinity between the Lewis acidic iodine molecules and the Lewis basic nitrogen atoms to form polyiodide ions. Considering their excellent iodine adsorption capacity and superior stability, PZ nanocomposites could be employed to effectively eliminate radioactive iodine.

In Situ Confined Synthesis of a Copper-Encapsulated Silicalite-1 Zeolite for Highly Efficient Iodine Capture.

Effective capture of radioactive iodine is highly desirable for decontamination purposes in spent fuel reprocessing. Cu-based adsorbents with a low cost and high chemical affinity for I2 molecules act as a decent candidate for iodine elimination, but the low utilization and stability remain a significant challenge. Herein, a facile in situ confined synthesis strategy is developed to design and synthesize a copper-encapsulated flaky silicalite-1 (Cu@FSL-1) zeolite with a thickness of ≤300 nm. The maximum iodine uptake capacity of Cu@FSL-1 can reach 625 mg g-1 within 45 min, which is 2 times higher than that of a commercial silver-exchanged zeolite even after nitric acid and NOX treatment. The Cu nanoparticles (NPs) confined within the zeolite exert superior iodine adsorption and immobilization properties as well as high stability and fast adsorption kinetics endowed by the all-silica zeolite matrix. This study provides new insight into the design and controlled synthesis of zeolite-confined metal adsorbents for efficient iodine capture from gaseous radioactive streams.

Luffa cylindrica Slow Pyrolysis and Solar Pyrolysis: Impact of Temperature and Heating Rate on Biochar Properties and Iodine Adsorption Performance

Recently, Luffa cylindrica has been drawing lots of attention in adsorption applications. However, the contaminated biomass needs to be properly disposed. Pyrolysis is a process capable of turning this type of residue into valuable product. Luffa cylindrica pyrolysis produces biochar which has been used as adsorbent for various cationic and organic species. Additionally, the use of solar power to heat the reactor reduces the environmental impact of pyrolysis. In this work, a lab-scale solar pyrolizer was built in a 40-dollar budget. This biomass was previously subjected to slow pyrolysis in an electrical reactor at various temperatures (300, 400, and 500 °C) and heating rates (2, 10, and 20 °C min−1) to assess the influence of these parameters on biochar properties. Further, the Luffa sponge sample was subjected to solar pyrolysis. The characterization methods of TG/DTG, FTIR, SEM, and HHV analysis were employed to assess biochar properties. Biochar adsorption performance was assessed by iodine adsorption experiments. Highest HHV (29.3 MJ kg−1) was obtained for the biochar from the 500 °C, 2 °C min−1 pyrolysis. Maximum iodine adsorption (162.9 mg g−1) was observed on the biochar produced at 400 °C, 2 °C min−1. Solar biochar had a 24.3 MJ kg−1 HHV and a Iodine adsorption of 115.2 mg g−1.Graphical Abstract

The Effect of Chemical Activation Method in the Preparation of Activated Carbon from Local Phoenix Dactylifera Waste Stems

Local date palm (Phoenix dactylifera) waste stems were used to prepare activated carbon (AC) using KOH, NaCl and ZnCl2 as activation agents. Carbonization was conducted at 600 °C for 2hr under nitrogen flow, followed by activation at 750 °C for 2 hr under carbon dioxide flow. AC was characterized using a scanning electron microscope (SEM), Attenuated total reflectance Fourier transform infrared (ATR FT-IR), Thermogravimetric analysis (TGA), Iodine adsorption, BET, micropores, and mesopores surface areas at different carbon-to-activation-agent-ratios (1:1, 1:2, 1:3). FT-IR spectra results showed a reduction in AC-NaCl bands compared to other AC, which indicates less functional surface groups. At 750 °C, the TGA analysis showed the carbon yield as AC-ZnCl2 > AC-NaCl > AC-KOH, however, among all samples, AC-NaCl at 1:2 ratio was the best in terms of iodine removal. This treated AC sample exhibited about 18.3 % maximum iodine removal, which indicates the high surface area and porosity with 550.4380 m2/g, 348.7432 m2/g, and 201.6947 m2/g BET, micropores and mesopores surface areas, respectively. In conclusion, the local Omani date palm waste stems can be used for AC production with a well porous structure using cheap and environmentally friendly salts as activation agents. In addition, the produced AC attained better adsorption characteristics among other alternatives.

Optimization of the Preparation of Activated Carbon from Prickly Pear Seed Cake for the Removal of Lead and Cadmium Ions from Aqueous Solution

In this study, we evaluated the use of prickly pear seed cake, a by-product of prickly pear seed oil extraction, as a new precursor for producing activated carbon by phosphoric acid activation, and the obtained carbon’s capacity for heavy metal removal from aqueous solution. Response surface methodology based on the full factorial design at two levels (24) was developed to reduce the number of experiments and reach optimal preparation conditions for the removal of cadmium and lead ions from aqueous solutions. Design Expert 11.1.2.0 Trial software was used for generating the statistical experimental design and analyzing the observed data. Factors influencing the activation process, such as carbonization temperature, activation temperature, activation time, and impregnation ratio, were studied. Responses were studied in depth with an analysis of variance to estimate their significance. Each response was outlined by a first-order regression equation demonstrating satisfactory correspondence between the predicted and experimental results as the adjusted coefficients of correlation. Based on the statistical data, the best conditions for the removal of heavy metals from aqueous solution by the obtained activated carbon were indicated. The maximum iodine number and methylene blue index were 2527.3 mg g−1 and 396.5 mg g−1, respectively, using activated carbon obtained at the following conditions: Tc = 500 °C, Ta = 500 °C, impregnation ratio = 2:1 (g H3PO4: g carbon), and activation time of two hours. The maximum adsorption reached 170.2 mg g−1 and 158.4 mg g−1 for Cd2+ and Pb2+, respectively, using activated carbon obtained at the following conditions: Tc = 600 °C, Ta = 400 °C, impregnation ratio = 2:1 (g H3PO4: g carbon), and activation time of one hour. The activated carbon obtained was characterized by Boehm titration, pH of point of zero charge (pHPZC), Brunauer–Emmett–Teller surface area (SBET), and scanning electron microscopy. Adsorption was performed according to different parameters: pH solution, adsorbent dosage, temperature, contact time, and initial concentration. Regeneration experiments proved that the obtained activated carbon still had a high removal capacity for Cd2+ and Pb2+ after five regeneration cycles.

Assessment of iodine concentrations of cooking salt commercialized in some municipalities in eastern Algeria.

Introduction. Iodine is a vital element for the thyroid hormones synthesis. Iodine deficiency disorders (IDD) are a major public health problem. In Algeria, iodine prophylaxis has been endowed by an executive decree imposing iodization of food salt. The assessment of the iodine content of cooking salt will contribute to updating the nutritional situation in the region. Objective. The iodine content was evaluated in packed cooking salt, commercialized in twelve municipalities located in East of Algeria. Material and methods. The samples number of 191 divided into 18 salt brands marked "iodized salt" were analyzed by iodometric titration. Results. Iodine content ≥ 15 ppm was noted in 80.7% of the collected salt samples, among which 57.6 % involved excess iodine (> 40 ppm). Iodine content ˂ 15 ppm was observed in 16.7% of the samples displayed insufficient. The non appearance of iodine was perceived in 2.6% of cases, such as in AinFakroun and Meskiana samples which exposed the lowest average concentrations (p<0,001). The minimum and maximum iodine content ranged between 0 ppm and 93 ppm with a median of 46.4 ppm. Conclusion. An increase in the rate of iodized salt samples (≥ 15 ppm) is noted, but in an irregular way between regions. Five municipalities display low iodine contents in salt, thus exposing their populations to increased risk of iodine deficiency, in particular in Meskiana and AïnFakroun. Conversely, another risk that should not be overlooked concerns the overiodized salt. The urgency is to control the quality of salt iodization at all levels, and at the determination of the iodized balance of the populations.

Quantitative Assessment of Iodine Intensity of Different Types of Lesions in the Low-Energy (LE) Images of Contrast-Enhanced Spectral Mammography (CESM)

Purpose: To assess the iodine enhancement intensity of breast lesions in low energy (LE) images obtained in contrast-enhanced spectral mammography (CESM) with different tissue compositions. Materials and Methods: A 50 mm dedicated phantom with different lesion insert and iodine insert were used to assess the enhancement intensity quantitatively. The target slab of the phantom consists of three lesions + iodine inserts together and 100% adipose equivalent,100% glandular equivalent inserts alone to mimic the adipose and glandular lesion without contrast-enhancement. Each iodine inserts having a concentration of 0.5 mgI/cm3, 1.0 mgI/cm3, 2.0 mgI/cm3. The phantom was exposed under semiautomated function at 28 kV, 30 kV, and 32 kV with Mo/Rh target/filter combination. Iodine intensity was estimated for three types of lesions at three breast equivalent compositions. Results: Lesions with fatty tissue had high intensity while lesions with glandular tissues had the minimum intensity. Among fatty lesions, highest mean intensity value (0.972±0.003) observed with minimum iodine concentration (F + 0.5 mgI/cm3). The highest mean intensity value (0.882±0.001) was found related to the glandular lesion with maximum iodine concentration (G + 2.0 mgI/cm3). The one-way ANOVA statistical test confirmed that mean intensity values were significantly varied among different lesions (P < 0.05). Conclusion: LE images obtained in CESM can be used to identify the different types of lesions without performing the full field digital mammography (FFDM) as an additional examination prior to the CESM procedure.

Synthesis and characterization of Ag-containing hydrophobic aluminosilicate aerogels for I2 capture

Ag-containing1 hydrophobic aluminosilicate aerogels capable of capturing I2 were prepared by sol-gelation from Na, Al, and Si alkoxides using co-solvent exchange, Ag/Na ion exchange, solvent exchange, silylation-induced surface hydrophobization, and ambient-pressure drying. The Ag contents, Brunauer-Emmett-Teller (BET) surface areas, and pore size distributions of aerogels depended on the solvent of the co-solvent exchange step, with isopropanol affording higher Ag contents and lower BET surface areas than water. This behavior was ascribed to the reaction of isopropanol-insoluble NaOH in gel pores during Ag/Na exchange with aqueous AgNO3 to form water-insoluble Ag2O. The Ag-containing hydrophobic aluminosilicate aerogel modified with hexamethyldisilazane contained meso- and macropores and exhibited a maximum iodine capture capacity of 0.555 g-I/g-sorbent, a BET surface area of 172 m2/g, a specific pore volume of 1.29 cm3/g, and an average pore size of 23.4 nm.

Influence of tree species on selenium and iodine partitioning in an experimental forest ecosystem

Storage of selenium and iodine can greatly vary between forest ecosystems, but the influence of tree species on partitioning and recycling of those elements remains elusive. In this study, contents of Se and I were measured in tree compartments, litterfall, humus, and soil horizons in monospecific stands of Douglas fir, pine, spruce, beech, and oak under identical climatic and edaphic conditions. The cycle of each element was characterized in terms of stocks and fluxes. Lowest concentrations were in wood (Se: 8–13 μg kg−1; I: <16.5 μg kg−1). Senescing organs had higher Se and I content, than the living parts of trees due to direct exposure to atmospheric deposition, with some variation between coniferous and deciduous trees. For all stands, low amounts of Se and I were involved in biological cycle as reflected by low root uptake. In humus, the enrichment of elements greatly increased with the stage of organic matter (OM) degradation with average factors of 10 and 20 for Se and I. OM degradation and element persistence in humus was influenced by tree species. Deciduous trees, with low biomass, and fast degradation of OM stored less Se and I in humus compared to fir and spruce with high humus biomass. Interestingly, tree species did not affect soil reserves of Se and I. Concentration ranges were 331–690 μg Se kg−1 and 4.3–14.5 mg I kg−1. However, the divergent vertical profiles of the elements in the soil column indicated greater mobility of I. Selenium concentrations regularly decreased with depth in correlation with OM and Fe oxides content. For iodine, the maximum iodine concentration at a soil depth of 15 to 35 cm was caused by a parallel precipitation/sorption behavior of aluminium and organic iodine dissolved in the topsoil.

Superior removal of iodine via cyclophosphazene-based conjugation-enriched cross-linking hybrid polymers

Lately, a series of adsorbents with conjugated structures were developed and found to be efficient for the removal of seriously hazardous radionuclide iodine. Herein, we present designed two novel cyclophosphazene-based electron-enriched π-conjugation hybrid polymers on the basis of the Friedel-Craft alkylation cross-linking strategy between hexachlorocyclotriphosphazene and thiophene or pyrrole, which was correspondingly abbreviated as CPP-Tp and CPP-Pyr. CPP-Tp and CPP-Pyr displayed excellent volatile iodine capture capacity up to 346 wt% and 297 wt%, respectively. Remarkably, in spite of the poor porosity, CPP-Tp presented outstanding iodine capture capacity per unit BET surface area up to 68 wt% comparing to the known iodine adsorbents to date, due to the strong chemical affinity between iodine molecules and the electron-enriched groups (heteroatoms and π-conjugated heterocyclic rings) in the frameworks. Besides, both CPP-Tp and CPP-Pyr showed rapid adsorption rate and high removal efficiency towards iodine in hexane solutions, and the maximum iodine adsorption capacities were also correspondingly calculated to be 588 mg/g and 625 mg/g for CPP-Tp and CPP-Pyr according to the Langmuir model. In addition, both CPP-Tp and CPP-Pyr exhibited favorable regeneration and recycle ability, indicating the cyclophosphazene-based conjugated CPP-Tp and CPP-Pyr might become one of potential candidates for the removal of iodine in the future.

Pyrolysis of furfural residue pellets: Physicochemical characteristics of pyrolytic pellets and pyrolysis kinetics

Biomass pelletization technology has recently gained significant interest, where pyrolyzed pellets have a very wide range of applications (e.g., as pellet fuels and adsorbents). In this study, furfural residue pellets (FRPs) were pyrolyzed at temperatures of 200–850 °C in a tube furnace. The physical and chemical properties of the pyrolyzed FRPs (PFRPs) obtained at various temperatures were compared, and the kinetic parameters of the pyrolysis process were calculated using the distributed activation energy model (DAEM). The PFRPs prepared at 450, 650, and 850 °C had higher volumetric energy densities than coal, whereas other properties (e.g., H/C and O/C ratios) were found to be similar to those of coal. The maximum iodine adsorption value (i.e. 317.8 mg/g) and methylene blue adsorption value (i.e. 96.4 mg/g) were achieved by pyrolysis at 650 °C and 450 °C, respectively, indicating that pyrolysis promoted the formation of micropore structures at 650 °C. Two-dimensional correlation spectroscopy (2D-COS) was employed to explore the temperature-sensitivity of the surface functional groups of the PFRPs. Based on comparison of the volumetric energy density, hydrophobicity, particle density, and strength, the PFRPs prepared at 250–300 °C afforded the best overall performance, where the sample prepared at 300 °C exhibited the maximum hydrophobicity.

Prediction of Intracerebral Hemorrhage After Endovascular Treatment of Acute Ischemic Stroke: Combining Quantitative Parameters on Dual-Energy CT with Clinical Related Factors

ObjectivesTo evaluate the predictive value of dual-energy CT (DECT) quantitative parameters and clinical influence factors for intracerebral hemorrhage (ICH) complications after endovascular treatment in patients with acute ischemic stroke (AIS). MethodsSeventy-two consecutive patients who underwent brain DECT immediately after endovascular treatment for AIS from November 2017 to October 2019 were included. Retrospectively, the volume of brain parenchymal hyperdensity area (HDA), the maximum iodine concentration, and maximum CT value on DECT images was evaluated and measured by two radiologists blinded to any clinical information independently. Follow-up CT imaging (24–72 h) were used to assess the development of ICH complications. DECT parameters and clinical influence factors were analyzed by Chi-square test or Fisher's exact test and Mann-Whitney U test. Receiver operating characteristic curves were generated for continuous variables. ResultsFollow-up CT images confirmed that forty of 72 patients (55.6%) developed ICH. The volume of HDA, median maximum iodine concentration and maximum CT value between ICH group and non-ICH group were significantly different (P < 0.001). Combining the DECT quantitative parameters with clinical predictors, receiver operating characteristic analysis revealed an area under the curve of 0.985, for identifying patients developing ICH with sensitivity, specificity, positive predictive value and negative predictive value were 90%, 100%, 100% and 88.9%, respectively. ConclusionsThree quantitative parameters of DECT and clinical predictors showed great predictive performance in identifing ICH complications in patients with brain parenchyma HDA after endovascular therapy, which may contribute to better clinical decision-making.

Separation of iodine using neem oil-cashew nut shell liquid based-phenol formaldehyde resin modified lignocellulosic biomatrices: Batch and column study

BackgroundManagement and separation of radioactive iodine from wastewater of nuclear power plants is time-dependent and needs lot of efforts. Changes of surface chemistry due to radioactive irradiations are the major issue for developing an efficient adsorbent for separation of radionuclei from wastewater. MethodsThis article presented a promising case of separation of non-radioactive iodine from aqueous solution using neem oil phenolic resin treated lignocellulosic biomass. The resin was prepared with some ingredients with known properties of radiation absorption. FindingsThe data pointed that the treated biomass has the efficacy of iodine separation from aqueous solution within wide range of pH. The iodine sorption followed the Langmuir isotherm indicating a monolayer surface adsorption reaction. The maximum iodine removal efficacy of the resin treated biomass was 3.64 mg/g. The iodine adsorption was found to follow the pseudo second order reaction. The kinetic analysis also indicated that both surface adsorption and intraparticle diffusion were likely to control the rate of iodine-adsorbent. The treated adsorbent also showed iodine removal efficacy in column mode. The resin used for the treatment of lignocellulosic biomass was prepared using cashew nut shell liquid and phenol-formaldehyde that are known for their radiation adsorption and antioxidant properties. Thus, neem oil cashew nut shell liquid containing phenol formaldehyde resin treated biomass is expected to be stable under radioactive radiation. As radioactive iodine generation is a common phenomenon for nuclear power plant the bio-based chemical modified lignocellulosic adsorbent could be a promising alternative. However, more detail investigations with radioactive iodine containing real wastewater from nuclear power plant is needed for validation of our statement.

Barbituric and thiobarbituric acid-based UiO-66-NH2 adsorbents for iodine gas capture: Characterization, efficiency and mechanisms

Efficient iodine gas capture is necessitated in many industries like spent nuclear fuel off-gas treatment in view of environmental protection and resource recycling. However, the adsorption efficiency and stability of the current adsorbents are limited. In the present work, efficient and stable barbituric and thiobarbituric acid-based UiO-66-NH2 adsorbents (i.e., UiO-66-NH-B.D and UiO-66-NH-T.D, respectively) have been synthesized by post-synthetic covalent modification. Characterization approaches, including SEM-EDS, TEM, XRD, FTIR, XPS, 1H NMR, TGA and BET, are used to obtain information on the properties and adsorption mechanisms of these metal-organic framework (MOF) adsorbents. The kinetics and mechanisms involved are studied in detail. The treatment efficiency and recyclability of the adsorbents are checked and compared with the adsorbents reported in previous works. The results show that the current adsorbents are potentially suitable for efficient iodine gas capture. High maximum iodine adsorption amount by UiO-66-NH-B.D and UiO-66-NH-T.D (1.17 and 1.33 g/g) was achieved under 75 °C. These new adsorbents are thermally stable for iodine adsorption and regenerated and reused with good performance. The adsorption mechanisms were revealed based on experimental results, indicating that iodine is adsorbed by both physisorption and chemisorption.

Flexible Oxygen‐Bridged Porous Organic Polymers for Adsorping and Fluorescence Sensing Iodine and the Formation of Liquid Complexes of POPs‐(Poly)Iodide Anions

AbstractThree flexible oxygen‐bridged porous organic polymers (TPG, HCCPA, and HPG) have been synthesized by nucleophilic substitution polymerization reactions. The three POPs display efficient and reversible adsorption of radioactive I2 in vapor and solution. In iodine vapor at 350 K, the maximum iodine adsorption capacities of TPG, HCCPA, and HPG are 5.29, 4.08, and 1.63 g g−1, respectively. The strong affinities for I2 are mainly due to the charge transfer of the POPs to iodine. Interestingly, with the decrease of iodine adsorption, charge transfer complexes of TPG, HCCPA, and HPG exhibit liquid, semi‐solid, and solid states, respectively. Furthermore, the three POPs have been found to fluorescently detect molecular iodine. The S–V quenching constants of TPG, HCCPA, and HPG are 2.01 × 104, 1.14 × 104, and 1.44 × 103 L mol−1, respectively. Their sensitivities decrease with the decrease of iodine adsorption. Pleasingly, HCCPA can sense molecular iodine by fluorescence in aqueous solution. Most probably, this is the first example of POPs used for fluorescent sensing molecular iodine in aqueous solution. Both TPG and HCCPA act as efficient adsorbents and chemical sensors of iodine.

Production of activated carbon from cocoa pods: Investigating benefits and environmental impacts through analytical chemistry techniques and life cycle assessment

Abstract Activated carbons currently represent a feasible adsorbent substrate for the removal of organic and inorganic compounds from solutions, due to their large specific surface area and high porosity. The chemical characterization of activated carbon and the environmental burden related to its production are a crucial point that challenges researchers all over the world for the generation of feasible absorbents at low cost, with low environmental impacts. This work aims at evaluating the preparation of activated carbons from cocoa pods using the Response Surface Methodology (RSM), and Life Cycle Assessment (LCA) to evaluate the environmental impacts of the process. Analysis of variance (ANOVA) and t-test are used to determine the major contributing factors to the production process. Results show that at a calcination time and temperature of 3 h and 600 °C respectively, coupled with an amount of 0.6 mol/L of potassium hydroxide (KOH) as activating agent are needed for the most suitable activated carbon production, in terms of maximum iodine number (995 mg/g) and yield (74.4%). The raw biomass and the produced activated carbon are characterized by thermogravimetric analysis (TGA), scanning electron microscopy (SEM), X-ray diffraction (XRD) and infrared spectroscopy (FTIR). The quantification of the major environmental impacts generated during the production process of activated carbon are analyzed through Life Cycle Assessment. Results show that the major contributor to environmental impact is the electricity used in the laboratory steps, with an average contribution throughout all the impact categories of almost 70%, a minimum to land use potential (≈9%), and a maximum to freshwater eco-toxicity (≈99%). Toxicity is related almost exclusively to the electric energy used (average ≈ 93% of contribution). Electricity is also the major contributor to Freshwater eutrophication potential (≈70%) together with distilled water (≈20%).

New Promises from an Old Friend: Iodine-Rich Compounds as Prospective Energetic Biocidal Agents.

For a very long time, frequent occurrences of biocrises have wreaked havoc on human beings, animals, and the environment. As a result, it is necessary to develop biocidal agents to destroy or neutralize active agents by releasing large amounts of strong biocides which are obtained upon detonation. Iodine is an efficient biocidal agent for bacteria, fungi, yeasts, viruses, spores, and protozoan parasites, and it is the sole element in the periodic table that can destroy microbes without contaminating the environment. Based on chemical biology, the mechanism of iodine as a bactericide may arise from oxidation and iodination reactions of cellular proteins and nucleic acids. However, because of the high vapor pressure causing elemental iodine to sublime readily at room temperature, it is inconvenient to use this material in its normal solid state directly as a biocidal agent under ambient conditions. Iodine-rich compounds where iodine is firmly bonded in molecules as a C-I or I-O moiety have been observed to be among the most promising energetic biocidal compounds. Gaseous products comprised of large amounts of iodine or iodine-containing components as strong biocides are released in the decomposition or explosion of iodine-rich compounds. Because of the detonation pressure, the iodine species are distributed over a large area greatly improving the efficacy of the system and requiring considerably less effort compared to traditional biocidal methods. The commercially available tetraiodomethane and tetraiodoethene, which possess superb iodine content also have the disadvantages of volatility, light sensitivity, and chemically reactivity, and therefore, are not suitable for use directly as biocidal agents. It is absolutely critical to synthesize new iodine-rich compounds with good thermal and chemical stabilities.In this Account, we describe our strategies for the syntheses of energetic iodine-rich compounds while maintaining the maximum iodine content with concomitant stability and routes for the synthesis of oxygen-containing iodine-rich compounds to improve the oxygen balance and achieve both high-energy and high-iodine content. In the other work, which involves cocrystals, iodine-containing polymers were also summarized. It is hoped that this Account will provide guidelines for the design and syntheses of new iodine-rich compounds and a route for the development of inexpensive, more efficient, and safer iodine-rich antibiological warfare agents of the future.

DELIGNIFICATION AND PHYSICOCHEMICAL CHARACTERISTICS OF NON-WOOD BIOMASS

The paper presents the of influence peroxide ammonium, alkali, nitric acid, organosolvent and "aqueous ammonia soaking" (AAS) delignification methods on the degree of removal of lignin from non-wood lignocellulosic waste walnut shell Juglans Regia L. and apricot seed Prunus Armeniaca L. It is shown that the maximum degree of delignification (94%) is achieved when processing raw materials with 42 wt% HNO3 and 20 wt% NaOH; the minimum is at peroxide-ammonia treatment (80%). We found that the greatest specific surface area (202 m2∙g-1) provided by the application 42 wt% HNO3, and a maximum iodine number (32 mg∙g-1) when using 25 wt% NH4OH. Delignification significantly increases the specific surface area (5 m2∙g-1 to 120–200 m2∙g-1) iodine number (6.35 mg∙g-1 to 25 to 32 mg∙g-1) of biomass, however, at 45–55% reduced exchange capacity of the material. The obtained cellulose intermediates having acceptable physical and chemical characteristics can be used for further preparation of available sorbents or ion exchange materials. In accordance with the principles of "green chemistry", it is proposed to dispose the spent delignification solutions from AAS and nitric acid methods in liquid nitrogen fertilizers producing.

Pyrolysis of furfural residue in a bubbling fluidized bed reactor: Biochar characterization and analysis

The pyrolysis characteristic of furfural residue (FR) was investigated in a fluidized bed reactor. The yield of biochar (BC) decreased whereas non-condensable gas yield increased with increasing temperature from 450 °C to 850 °C. The minimum BC yield (41.67 wt%) was found with addition of kaolin at 650 °C, while the maximum non-condensable gas yield (48.00 wt%) was obtained at 850 °C without additives. Furthermore, the maximum condensate yield (20.63 wt%) was observed at 650 °C with Ca-bentonite addition. Both Ca-bentonite and kaolin decreased the BC yield, while CaO promoted the BC yield. The contents of carbon, nitrogen and sulfur in BC were enriched at different temperatures. Ca-bentonite, kaolin and CaO resulted in more amount of protrusions on the BC surface and improved BC pore structures. Iodine and methylene blue adsorption values of BC were higher than that of FR and the maximum iodine adsorption value (279.6 mg/g) was obtained at 650 °C without additives. CaO remarkably increased methylene blue adsorption value, reaching the maximum value of 168.7 mg/g at 450 °C. A possible formation pathway of BC during FR pyrolysis was also proposed.