Removal of odorous compounds emitted from a food-waste composting facility in Korea using a pilot-scale scrubber.

Monitoring and control of odorous compound emissions have been enforced by the Korean government since 2005. One of the point sources for these emissions was from food waste composting facilities. In this study, a pilot-scale scrubber installed in a composting facility was evaluated for its performance in the removal of malodorous compounds. The exhaust stream contained ammonia and methylamine as the major odorants detected by the threshold odor test and various instrumental techniques (GC-FID, FPD, MS and HPLC/UV). For the scrubber operation, the column was randomly packed with polypropylene Hi-Rex 200, while aqueous sulfuric acid was selected as the scrubbing solution. To achieve 95% removal, the scrubber must be operated by using H2SO4 solution with pH at < 6.5, liquid to gas ratio > 4.5, gas loading rate < 1750 m3/m3-hr and contact time < 0.94 s. The scrubber performance was further evaluated by determining the mass transfer coefficients and then monitoring for 355 days of operation. The pilot-scale scrubber maintained > 95% ammonia and methylamine removal efficiencies despite the fluctuations in the inlet (from composting facility exhaust stream) concentration. The optimum operating conditions and scrubber performance indicators determined in this study provides a basis for the design of a plant-scale scrubber for treatment of composting facility gas emissions.

Removal characteristics of sulfuric acid aerosols from coal-fired power plants.

With increasing attention on sulfuric acid emission, investigations on the removal characteristics of sulfuric acid aerosols by the limestone gypsum wet flue gas desulfurization (WFGD) system and the wet electrostatic precipitator (WESP) were carried out in two coal-fired power plants, and the effects of the WFGD scrubber type and the flue gas characteristics were discussed. The results showed that it was necessary to install the WESP device after desulfurization, as the WFGD system was inefficient to remove sulfuric acid aerosols from the flue gas. The removal efficiency of sulfuric acid aerosols in the WFGD system with double scrubbers ranged from 50% to 65%, which was higher than that with a single scrubber, ranging from 30% to 40%. Furthermore, the removal efficiency of WESP on the sulfuric acid aerosols was from 47.9% to 52.4%. With increased concentrations of SO3 and particles in the flue gas, the removal efficiencies of the WFGD and the WESP on the sulfuric acid aerosols were increased. IMPLICATIONS: Investigations on removal of sulfuric acid aerosols by the WFGD and the WESP in the power plants were aimed at the control of sulfuric acid emission. The results showed that the improvement of the WFGD system was beneficial for the reduction of sulfuric acid emission, while the WESP system was essential to control the final sulfuric acid aerosol concentration.

Removal of furan and phenolic compounds from simulated biomass hydrolysates by batch adsorption and continuous fixed-bed column adsorption methods.

It has been proposed to remove all potential inhibitors and sulfuric acid in biomass hydrolysates generated from dilute-acid pretreatment of biomass, based on three steps of sugar purification process. This study focused on its first step in which furan and phenolic compounds were selectively removed from the simulated hydrolysates using activated charcoal. Batch adsorption experiments demonstrated that the affinity of activated charcoal for each component was highest in the order of vanillic acid, 4-hydroxybenzoic acid, furfural, acetic acid, sulfuric acid, and xylose. The affinity of activated charcoal for furan and phenolic compounds proved to be significantly higher than that of the other three components. Four separation strategies were conducted with a combination of batch adsorption and continuous fixed-bed column adsorption methods. It was observed that xylose loss was negligible with near complete removal of furan and phenolic compounds, when at least one fixed-bed column adsorption was implemented in the strategy.

Bio-desulfurization of biogas using acidic biotrickling filter with dissolved oxygen in step feed recirculation.

Triple stage and single stage biotrickling filters (T-BTF and S-BTF) were operated with oxygenated liquid recirculation to enhance bio-desulfurization of biogas. Empty bed retention time (EBRT 100-180 s) and liquid recirculation velocity (q 2.4-7.1 m/h) were applied. H2S removal and sulfuric acid recovery increased with higher EBRT and q. But the highest q at 7.1 m/h induced large amount of liquid through the media, causing a reduction in bed porosity in S-BTF and H2S removal. Equivalent performance of S-BTF and T-BTF was obtained under the lowest loading of 165 gH2S/m(3)/h. In the subsequent continuous operation test, it was found that T-BTF could maintain higher H2S elimination capacity and removal efficiency at 175.6±41.6 gH2S/m(3)/h and 89.0±6.8% versus S-BTF at 159.9±42.8 gH2S/m(3)/h and 80.1±10.2%, respectively. Finally, the relationship between outlet concentration and bed height was modeled. Step feeding of oxygenated liquid recirculation in multiple stages clearly demonstrated an advantage for sulfide oxidation.

Purification of xylose in simulated hemicellulosic hydrolysates using a two-step emulsion liquid membrane process.

Purification of xylose in simulated hemicellulosic hydrolysates was attempted using a two-step emulsion liquid membrane (ELM) process. The effects of various experimental variables on extraction of each component in the hydrolysates were investigated in the ELM steps. In the first ELM step, acetic acid could be selectively removed from the hydrolysates and highly enriched in the stripping phase, and loss of xylose was insignificant. In the second ELM step, sulfuric acid could be selectively removed from simulated acetic acid-free hemicellulosic hydrolysates and somewhat enriched in the stripping phase. There was just small loss of xylose, and the final pH of the feed phase approached a pH level suitable for ethanol fermentation. Also, concentration of xylose in the feed phase was attained as an incidental outcome during each ELM run. Conclusively, the two-step ELM process was found to be a promising futuristic technology for purification of sugars in real hemicellulosic hydrolysates.

Evolutionary multi-objective optimization based comparison of multi-column chromatographic separation processes for a ternary separation.

Performance characteristics of two advanced multi-column chromatographic separation processes with discontinuous feed, Multi-Column Recycling Chromatogrphy (MCRC) and Japan Organo (JO), were investigated for a ternary separation using multi-objective optimization with an evolutionary algorithm. Conventional batch process was used as a reference. Fractionation of a concentrated acid hydrolysate of wood biomass into sulfuric acid, monosaccharide, and acetic acid fractions was used as a model system. Comparison of the separation processes was based on selected performance parameters in their optimized states. Flow rates and step durations were taken as decision variables whereas the column configuration and dimensions were fixed. The MCRC process was found to be considerably more efficient than the other processes with respect to eluent consumption. The batch process gave the highest productivity and the JO process the lowest. Both of the multi-column processes gave significantly higher monosaccharide yield than the batch process. When eluent consumption and monosaccharide yield are taken into account together with productivity, the MCRC process was found to be the most efficient in the studied case.

Recovery of H2SO4 from an acid leach solution by diffusion dialysis.

Diffusion dialysis with a series of anion exchange membranes was used to recover H(2)SO(4) from an acid leach solution produced during the vanadium manufacturing process. The effects of sulfuric acid, FeSO(4) and VOSO(4) concentration, flow rate and flow rate ratio on the recovery of H(2)SO(4) were investigated. The results showed that sulfuric acid permeated well through the membranes used, while metal ions were efficiently rejected. The recovery of H(2)SO(4) increased as the sulfate concentration of the feed increased and the flow rate ratio of water to feed increased. More than 80% of the H(2)SO(4) could be recovered from the leach solution which contained 61.7 g/L free H(2)SO(4), 11.2 g/L Fe and 4.60 g/L V at a flow rate of 0.19x10(-3) m(3)/h m(2). V and Fe ion rejection were within 93-95 and 92-94%, respectively. A preliminary economic evaluation revealed that an investment in this process could be recovered within 27 months.

General occurrence of the glucosinolate glucocochlearin within the Cochlearia genus.

A natural compound, glucocochlearin, was isolated from the aerial parts of 10 different Cochlearia species. The purification of this compound was achieved through HPLC. The identity of the product was established mainly on the basis of spectroscopic NMR (1H, 13C, COSY, TOCSY, HMQC, HMBC, J-MOD) and high resolution mass spectroscopy data. This compound can be considered as a chemomarker of the genus Cochlearia.

Recovery of H2SO4 from waste acid solution by a diffusion dialysis method.

A diffusion dialysis method using anion exchange membrane was used to recover H2SO4 from waste sulfuric acid solution produced at the diamond manufacturing process. Effects of flow rate, operation temperature, and metal ion concentration on the recovery of H2SO4 were investigated. The recovery of H2SO4 increased with the concentration of H2SO4 and operation temperature. It also increased with the flow rate ratio of water/H2SO4 solution up to 1, above which no further increase was observed. The flow rate did not affect the rejection of Fe and Ni ions. About 80% of H2SO4 could be recovered from waste sulfuric acid which contained 4.5M free-H2SO4 at the flow rate of 0.26x10(-3) m3/hm3. The concentration of recovered H2SO4 was 4.3M and the total impurity was 2000 ppm. Preliminary economic evaluation has revealed that the dialysis system is highly attractive one that has payback period of only few months.

Field evaluation of nanofilm detectors for measuring acidic particles in indoor and outdoor air.

This field evaluation study was conducted to assess new technology designed to measure number concentrations of strongly acidic ultrafine particles. Interest in these particles derives from their potential to cause adverse health effects. Current methods for counting and sizing airborne ultrafine particles cannot isolate those particles that are acidic. We hypothesized that the size-resolved number concentration of such particles to which people are exposed could be measured by newly developed iron nanofilm detectors on which sulfuric acid (H2SO4*) droplets produce distinctive ringed reaction sites visible by atomic force microscopy (AFM). We carried out field measurements using an array of samplers, with and without the iron nanofilm detectors, that allowed indirect comparison of particle number concentrations and size-resolved measures of acidity. The iron nanofilm detectors are silicon chips (5 mm x 5 mm x 0.6 mm) that are coated with iron by vapor deposition. The iron layer was 21.5 or 26 nm thick for the two batches used in these experiments. After exposure the detector surface was scanned topographically by AFM to view and enumerate the ringed acid reaction sites and deposited nonacidic particles. The number of reaction sites and particles per scan can be counted directly on the image displayed by AFM. Sizes can also be measured, but for this research we did not size particles collected in the field. The integrity of the surface of iron nanofilm detectors was monitored by laboratory analysis and by deploying blank detectors and detectors that had previously been exposed to H2SO4 calibration aerosols. The work established that the detectors could be used with confidence in temperate climates. Under extreme high humidity and high temperature, the surface film was liable to detach from the support, but remaining portions of the film still produced reliable data. Exposure to ambient gases in a filtered air canister during the field tests did not affect the film quality. Sampling sessions to obtain particle measurements were scheduled for two 1-week periods in each of the four seasons at a rural site in Tuxedo, New York. This schedule was selected to test outdoor performance of the iron nanofilm detectors under a variety of weather conditions. To seek possible artifacts caused by local source differences, we also sampled outdoors for two 1-week sessions during the winter in New York City. Indoor tests were conducted in the cafeteria at the Nelson Institute of Environmental Medicine (NIEM) in Tuxedo and in a residence in Newburgh, New York. For the outdoor tests we simultaneously deployed several particle samplers to obtain several measures: --the number concentration of acidic and total particles that penetrated the 100-nm cut size of a microorifice impactor (MOI) and were electrically precipitated in an electrostatic aerosol sampler (EAS) onto the iron nanofilm detectors; --the number concentrations of acidic and total particles estimated from detectors placed in a simple ultrafine diffusion monitor (UDM); --the size-fractionated mass concentration of strong acids in samples from the submicrometer collection stages of the MOI and from a polycarbonate filter, parallel to the EAS, that also collected particles penetrating the MOI's 100-nm cut size; and --the number concentration of all ambient particles with diameters of 300 nm or smaller, determined using a scanning mobility particle sizer (SMPS). In the results from these samplers, the mean number concentration of acidic particles ranged from about 100 to 1800/cm3, representing 10% to 88% of all ambient ultrafine particles for the different seasons and sites. The number concentration did not correlate with the acidic mass (hydrogen ion, or H+, content) for particles smaller than 100 nm in diameter. This was not surprising because a single 100-nm particle may contain the same acid volume as many smaller particles if they are pure acid droplets. The ambient concentrations of H+, sulfate (SO4(2-)), and ammonium (NH4+), collected on polycarbonate filters and measured as a function of particle size, were highest for particles with diameters between 280 and 530 nm, but the size distributions also suggested that a small peak of these ions existed in the particle size range below 88 nm. The H+ / SO4(2-) ratio was somewhat higher for particles below 88 nm, suggesting greater excess acidity for these small particles. Our continuous monitoring showed that airborne concentrations of ultrafine particles varied substantially with time. The iron nanofilm detectors provided a time-integrated number concentration over several days or weeks. The counts on the detectors were relatively low for some of the sampling sessions, resulting in high statistical errors in calculations. Nonetheless, agreement of the mean values was remarkably good for some of the measurements. In future tests, longer collection times and new technologies, such as improved particle-charging methods for electrical precipitation samplers, could provide more efficient collection of particles onto the detectors, higher counts, and lower count-associated uncertainties. In general, concentrations of ultrafine particles determined by AFM analysis of the detectors in the MOI-EAS and UDM appeared to underestimate the total number concentration as determined by comparison samplers. The ability to monitor airborne acidic particles provided by these iron nanofilm detectors enlarges the array of air quality variables that can be measured. This may help to resolve some of the outstanding questions related to causal relations between demonstrated health effects of ambient particles and particulate matter (PM) components.

Separation of H(2)SO(4) + CuSO(4) mixture by diffusion dialysis.

Diffusion dialysis of aqueous solution of H(2)SO(4) + CuSO(4) has been investigated in a two-compartment cell with an anion-exchange membrane Neosepta-AFN. The experiments have proved that sulfuric acid permeates well through the membrane used, while cupric sulfate is efficiently rejected. This operation is very effective at high acid concentrations and low concentrations of cupric sulfate. Furthermore, it has been found that even at the highest concentration of CuSO(4), the rejection coefficient is higher than 0.965. The flux of CuSO(4) calculated from the time dependences of the CuSO(4) concentration is negatively influenced by increasing acid concentration.

Tuning the diffusion dialysis performance by surface cross-linking of PPO anion exchange membranes--simultaneous recovery of sulfuric acid and nickel from electrolysis spent liquor of relatively low acid concentration.

The results of the development of the industrial diffusion dialysis technology and the unit based on it for sulfate acid recovery from nickel electrolysis waste have been considered. Unlike most acid recovery systems, this system has a relatively low acid concentration and the main aim is to recover both nickel and acid sulfate by recycling the waste and the recovered acid to the respective steps of electrolysis process. So the waste volume control seems to be the most important thing. To satisfy with this new request, the membrane is surface-cross-linked with aqueous ammonium to decrease waste volume expansion caused by the water osmosis. The results showed that the best membrane for such operation is the one that cross-linked at least 8 h with a volumetric expansion factor (volumetric ratio of waste to feed) less than 1.1. Pilot diffusional runs were conducted with this membrane at various feed flow rate and flow ratio of stripping water and feed. After comprehensively considering all factors, the range of feed flow and the flow ratio has been recommended to be 1.2-1.8 l/h and 1.05-1.1, respectively. Under these conditions, nickel leakage can be controlled within 4% and the acid recover ratio can attain as high as 66-72%. The recovered acid can be recycled to the back-extraction step by mixing it with high concentration acid and the waste recycled to the initial leaching stage by adjusting the acid concentration to recover valuable metal nickel and the residual acid. Therefore, the new technology discards nothing and shows many advantages whether in environmental aspect or economical aspect and thus should be deserved attention.

Antithrombin-mediated anticoagulant activity of sulfated polysaccharides: different mechanisms for heparin and sulfated galactans.

We investigated the mechanisms of anticoagulant activity mediated by sulfated galactans. The anticoagulant activity of sulfated polysaccharides is achieved mainly through potentiation of plasma cofactors, which are the natural inhibitors of coagulation proteases. Our results indicated the following. 1) Structural requirements for the interaction of sulfated galactans with coagulation inhibitors and their target proteases are not merely a consequence of their charge density. 2) The structural basis of this interaction is complex because it involves naturally heterogeneous polysaccharides but depends on the distribution of sulfate groups and on monosaccharide composition. 3) Sulfated galactans require significantly longer chains than heparin to achieve anticoagulant activity. 4) Possibly, it is the bulk structure of the sulfated galactan, and not a specific minor component as in heparin, that determines its interaction with antithrombin. 5) Sulfated galactans of approximately 15 to approximately 45 kDa bind to antithrombin but are unable to link the plasma inhibitor and thrombin. This last effect requires a molecular size above 45 kDa. 6) Sulfated galactan and heparin bind to different sites on antithrombin. 7) Sulfated galactans are less effective than heparin at promoting antithrombin conformational activation. Overall, these observations indicate that a different mechanism predominates over the conformational activation of antithrombin in ensuring the antithrombin-mediated anticoagulant activity of the sulfated galactans. Possibly, sulfated galactan connects antithrombin and thrombin, holding the protease in an inactive form. The conformational activation of antithrombin and the consequent formation of a covalent complex with thrombin appear to be less important for the anticoagulant activity of sulfated galactan than for heparin. Our results demonstrate that the paradigm of heparin-antithrombin interaction cannot be extended to other sulfated polysaccharides. Each type of polysaccharide may form a particular complex with the plasma inhibitor and the target protease.

Vacancy ion-exclusion chromatography of aromatic carboxylic acids on a weakly acidic cation-exchange resin.

Determination of aromatic carboxylic acids by conventional ion-exclusion chromatography is relatively difficult and methods generally rely on hydrophobic interaction between the solute and the resin. To overcome the difficulties in determining aromatic carboxylic acids a new approach is presented, termed vacancy ion-exclusion chromatography, which is based on use of the sample as mobile phase and an injection of aqueous 10% methanol onto a weakly acidic cation-exchange column (TSKgel OApak-A). Highly sensitive conductivity detection occurred with sharp and well-shaped peaks, leading to very efficient separations. The effects of sulfuric acid concentration added to the mobile phase, flow-rate, and column temperature on the retention volume of tested aromatic carboxylic acids was investigated. Retention times were found to be affected by the concentration of the analytes in the mobile phase and to some extent also by the addition of an organic modifier such as methanol to the injected water sample. Separation of sulfuric acid (SA), naphthalenetetracarboxylic acid (NTCA), phthalic acid (PA) and benzoic acid (BA) was satisfactory using this new approach. Detection limits were 0.66, 0.67, 0.42 and 0.86 microM and detector responses were linear in the range 1-100, 1-80, 2.5-100 and 10-40 microM, for SA, NTCA, PA and BA, respectively. Precision for retention times was 0.36% and for peak areas was 1.5%.

Inhibitors of protein tyrosine kinase pp60v-src: sterol sulfates from the brittle star Ophiarachna incrassata.

Bioactivity-guided fractionation of the extracts of the green brittle star Ophiarachna incrassata using a protein tyrosine kinase pp60v-src inhibition assay led to the isolation of a new sterol sulfate [2] together with four known ones (1,3-5). All five compounds were found to inhibit protein tyrosine kinase pp 60v-src.

Antibacterial and antifungal sulfated alkane and alkenes from the hepatopancreas of the ascidian Halocynthia roretzi.

Four new antibacterial and antifungal sulfates, 2,6-dimethylheptyl sulfate [1], (4Z,7Z)-4,7-decadienyl sulfate [2], (4Z,7E)-4,7-decadienyl sulfate [3], and (3Z,6Z)-3,6,9-decatrienyl sulfate [4], have been isolated from the hepatopancreas of the ascidian Halocynthia roretzi. The structures were determined by spectral analysis.

Liquid chromatographic separation of alkanesulfonate and alkyl sulfate surfactants: effect of ionic strength.

The retention of alkanesulfonate and alkyl sulfate surfactants, which was determined on a reversed stationary phase as a function of mobile-phase ionic strength, is consistent with a double-layer type interaction at the stationary-phase surface. Increasing the mobile-phase ionic strength not only increases retention but also improves resolution because peak widths are significantly reduced. The type of cation provided by the ionic strength salt also enhances retention, reduces peak width, and improves resolution. Lithium hydroxide is an ideal electrolyte for the separation of multicomponent mixtures of alkanesulfonate and alkyl sulfate surfactants. When the column effluent is passed through a postcolumn anion micromembrane suppressor, the conductivity due to the electrolyte is minimized and conductivity detection is sensitive, yielding a detection limit of about 0.3 nmol of injected analyte for a 3:1 signal:noise ratio. Multicomponent alkanesulfonate and alkyl sulfate mixtures from C2 to C18 are baseline resolved by using a mobile-phase gradient whereby CH3CN concentration increases and LiOH concentration decreases.

Changes in the structure and biological property of N----O sulfate-transferred, N-resulfated heparin.

The N----O sulfate transfer of heparin has been investigated as an approach to chemical 3-O-sulfation of the D-glucosamine residues in heparin. The pyridinium salt of porcine heparin was heated at 90 degrees C in solid state for 90 min (in vacuo over P2O5) to effect the transfer of the N-sulfate groups to the HO groups in the polysaccharide, followed by N-resulfation. The product (N----O sulfate-transferred, N-resulfated heparin (ST heparin] was depolymerized with HONO to generate a mixture of di- and higher oligosaccharides. The borohydride-reduced oligosaccharides were separated on Bio-Gel P-4 and DEAE-Sephacel. The disaccharide trisulfate fraction (10.4% yield) was found to be a mixture of nearly equal amounts of IdoA(2-SO4)-AManR(3,6-diSO4) and IdoA(2,3-diSO4)-AManR(6-SO4), where IdoA represents L-iduronic acid and AManR represents the alditol formed by reduction of 2,5-anhydro-D-mannose with NaBH4. Chemical and NMR spectroscopic analyses revealed that the N----O sulfate transfer proceeded preferentially at HO-3 positions in both 6-O-sulfo-D-glucosamine and 2-O-sulfo-L-iduronic acid residues. Chromatography on antithrombin III-Sepharose gel indicated that the structural change involved in ST heparin resulted in an obvious increase in the ability to bind antithrombin III. Biological examination also indicated that this structural change resulted in moderate increases in all the activities (blood anti-clotting, anti-Factor IIa, and anti-Factor Xa) and in the strength of intrinsic fluorescence of antithrombin III.

Analysis of alkyl sulfates in protein solutions by isocratic and gradient ion chromatography.

An ion-chromatographic analysis for separation and quantitation of long-chain alkyl sulfates in both commercial samples of sodium dodecyl sulfate (SDS) (lauryl sodium sulfate) and protein solutions was developed. The separation was performed on a hydrophobic resin-based column utilizing tetrabutylammonium hydroxide as an ion-pair reagent and acetonitrile as an organic modifier. Sensitive and selective detection of alkyl sulfates was achieved with an anion suppressor and a conductivity detector. Gradient elution with acetonitrile was developed for the detection of a broad range of alkyl chain lengths (C-10--C-20) at high sensitivity. Because of the wide linear range of this method (0.2-700 micrograms/ml), trace levels of C-10, C-14, C-16, C-18, and C-20 alkyl sulfates can be accurately measured in the presence of high concentrations of C-12 alkyl sulfate (SDS). Thus the alkyl sulfate purity of commercial SDS solutions can be accurately and precisely determined without any sample treatment. For analysis of alkyl sulfates from protein solutions, sample treatment consisted of a one-step ion-pair extraction prior to chromatographic resolution and quantitation. Alkyl sulfates from 2-150 micrograms/ml were recovered in high yield from wide variety of protein solutions.

Preparation of [35S]sulfobromophthalein of high specific activity.

Study of the hepatocyte transport mechanism of organic anions such as bilirubin and sulfobromophthalein has been limited by the relatively low specific activities of these ligands. [3H]Bilirubin and [35S]sulfobromophthalein have been available with specific activities of only approximately 100 mCi/mmol. We now report a relatively simple procedure to prepare [35S]sulfobromophthalein at a specific activity of approximately 3000 mCi/mmol. This compound is radiochemically pure and serves as a tracer for authentic sulfobromophthalein as judged by chromatography, hepatocyte uptake, metabolism, and biliary excretion. Use of this material as a photoaffinity probe and as a transported ligand may permit dissection and understanding of its transport mechanism.