Solid-phase System Research Articles

Solid-phase treatment with the fungus Trametes versicolor substantially reduces pharmaceutical concentrations and toxicity from sewage sludge

For safe biosolid-land-applying, sludge should be contaminant-free. However, it may contain important amounts of micropollutants, not removed in the wastewater-treatment-processes. An alternative treatment with the fungus Trametes versicolor was applied in sterile solid-phase systems consisting of sludge and a lignocellulosic substrate. Fungal colonization and activity were demonstrated during the process, according to monitoring of ergosterol, laccase activity and the naproxen-degradation test (ND24). Fourteen out of 43 analyzed pharmaceuticals were found in the raw sludge. After treatment, phenazone, bezafibrate, fenofibrate, cimetidine, clarithromycin, sulfamethazine and atenolol were completely removed, while removals between 42% and 80% were obtained for the remaining pharmaceuticals. Toxicological analyses ( Daphnia magna, Vibrio fischeri and seed germination) showed an important reduction in sludge toxicity after treatment. Results suggest that a solid-phase treatment with T. versicolor may reduce the ecotoxicological impact of micropollutants present in sewage sludge. This is the first report of a fungal-approach for elimination of emerging pollutants from biosolids.

Organophosphorus pesticide residues in raw milk and infant formulas from Spanish northwest

Residue levels of seven organophosphorus pesticides (OPPs), widely used as dairy cattle ectoparasiticides or in crops used for animal feed, were determined in raw milk and infant formulas. A total of 312 samples were collected (70 from infant formulas and 242 from raw milk) biweekly during a 24-month period. Pesticides were extracted by means of a solid phase system into acetone. An extract aliquot of acetone was injected into a gas chromatograph (GC) with a nitrogen-phosphorus detector. Recoveries of pesticides spiked in milk samples were 62.2 – 97.2 %. The frequency of total samples containing detectable levels of OPP residues was 6.73 % in total milk and 8.67 % in raw milk. The highest percentage incidence measured was for dichlorvos (5.78 %), followed by coumaphos (2.06 %), and parathion methyl (0.83 %). The range of positive results was calculated to be between 0.005 and 0.220 mg kg− 1. No residue was detected in the final product (infant formulas), so any risk to consumer health, especially to children's health, would be limited.

Cross-linking<i> Enset</i> Starch Microspheres, Physicochemical Characterization and Study on Their Drug Loading and Release Properties

Enset starch was cross-linked in solid phase systems using sodium hexametaphosphate (SHMP) as crosslinking agent under different microwave powers and reaction times to investigate its drug-release-sustaining ability. Paracetamol was used as a model drug. The swelling and water-binding capacities and the peak viscosity of the cross-linked enset starch varied with cross-linking parameters. The degree of cross-linking (DC) also varied with reaction time. The drug loading ratio (D) and encapsulation efficiency (E) of the crosslinked starch increased significantly compared to the native starch. Loading time markedly affected the two parameters. Increasing loading time from 45 to 150 min boosted the D and E, respectively, from 4.7 to 10.4% and 9.4 to 20.7%. Drug concentration in the loading medium affected both parameters but in the opposite way. Native enset starch matrices loaded with the model drug released 96.4% of their content within 1.5 h while the cross-linked ones released only 39.5%. After 24 h, cross-linked enset starch matrices released 95.6% of the drug implying their ability to sustain drug release, and hence their potential use as drug-release-sustaining pharmaceutical excipient. Keywords: enset starch, degree of cross-linking, loading ratio, encapsulation efficiency, drug-release

ChemInform Abstract: Phase-Transfer Catalysis in the Chemistry of Aliphatic Nitro Compounds. Part 1. Alkylation of Trinitromethane Alkali Salts, e.g. (I), Under Phase-Transfer Catalysis in Solid Liquid Phase Systems.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Activated Carbon Monolith Catalysts (ACMC): A New and Novel Catalyst System

Monolithic catalysts have been widely used in gas–solid phase systems for a variety of environmental applications. More recently they are being investigated for use in three phase systems however there are few catalysts available commercially for these applications. Monoliths offer several advantages over traditional three phase slurry and trickle bed systems, in that they can be easily separated from the system, offer low pressure drop and high rates of adiabatic cooling, and are mostly linear when scaling up. In this chapter, we present a new and novel three phase catalyst, Activated Carbon Monolith Catalyst (ACMC), utilizing a newly developed integrated activated carbon monolith as an alternative to granular catalysts.

Degradation of naproxen and carbamazepine in spiked sludge by slurry and solid-phase Trametes versicolor systems

Growth and activity of the white-rot fungus Trametes versicolor on sewage sludge were assessed in bioslurry and solid-phase systems. Bioslurry cultures with different loads of sludge (10%, 25% and 38%, w/v) were performed. A lag phase of at least 2 d appeared in the 25 and 38%-cultures, however, the total fungal biomass was higher for the latter and lower for the 10%-culture after 30 d, as revealed by ergosterol determination. Detectable laccase activity levels were found in the 10 and 25%-cultures (up to 1308 and 2588 AU L −1, respectively) while it was negligible in the 38%-culture. Important levels of ergosterol and laccase were obtained over a 60 d period in sludge solid-phase cultures amended with different concentrations of wheat straw pellets as lignocellulosic bulking material. Degradation experiments in 25%-bioslurry cultures spiked with naproxene (NAP, analgesic) and carbamazepine (CBZ, antiepileptic) showed depletion of around 47% and 57% within 24 h, respectively. Complete depletion of NAP and around 48% for CBZ were achieved within 72 h in sludge solid cultures with 38% bulking material. CBZ degradation is especially remarkable due to its high persistence in wastewater treatment plants. Results showed that T. versicolor may be an interesting bioremediation agent for elimination of emerging pollutants in sewage sludge.

Estimation of solid vapor pressures from supercritical CO 2 + biomolecule systems using a PSO algorithm

A method to estimate the solid vapor pressures of biomolecules using a biologically deriver algorithm is presented. The solid vapor pressure is usually small for most solid compounds and in many cases available experimental techniques cannot be used to obtain accurate values. Therefore, estimation methods must be used to obtain these data. Five binary gas–solid phase systems of supercritical CO 2 + biomolecule containing caffeine, artemisinin, capsaicin, cholesterol, and β-carotene are considered in this study. Particle swarm optimization is used for minimize the difference between calculated and experimental solubility. Then, the solid vapor pressures of biomolecules are calculated from solubility data. The Peng–Robinson equation of state with the Wong–Sandler mixing rules are used to evaluate the fugacity coefficient on the systems. The results show that the method presented is reliable enough and can be used with confidence to estimate the solid vapor pressure of any organic biomolecule.

Intermolecular shielding contributions studied by modeling the (13)C chemical-shift tensors of organic single crystals with plane waves.

In order to predict accurately the chemical shift of NMR-active nuclei in solid phase systems, magnetic shielding calculations must be capable of considering the complete lattice structure. Here we assess the accuracy of the density functional theory gauge-including projector augmented wave method, which uses pseudopotentials to approximate the nodal structure of the core electrons, to determine the magnetic properties of crystals by predicting the full chemical-shift tensors of all (13)C nuclides in 14 organic single crystals from which experimental tensors have previously been reported. Plane-wave methods use periodic boundary conditions to incorporate the lattice structure, providing a substantial improvement for modeling the chemical shifts in hydrogen-bonded systems. Principal tensor components can now be predicted to an accuracy that approaches the typical experimental uncertainty. Moreover, methods that include the full solid-phase structure enable geometry optimizations to be performed on the input structures prior to calculation of the shielding. Improvement after optimization is noted here even when neutron diffraction data are used for determining the initial structures. After geometry optimization, the isotropic shift can be predicted to within 1 ppm.

HLA type and risk of alloimmunization in sickle cell disease

Red blood cell (RBC) transfusions are frequently required to treat patients with sickle cell disease (SCD) [1]. One of the most serious complications of repeat transfusion is alloimmunization to RBC antigens [2]. Because human leukocyte antigen (HLA) genes mediate the response to foreign antigens, particular HLA alleles may predispose to the development of alloimmunization in patients with SCD who receive multiple transfusions. We conducted a case-control study to determine if particular HLA alleles are associated with alloimmunization and whether HLA homozygosity influences the risk of developing RBC alloantibodies. High-resolution HLA genotyping was performed on DNA samples from 159 multiply transfused patients with SCD. HLA allele frequencies were compared between alloantibody-positive and alloantibody-negative groups. The HLA-DRB1 * 1503 allele was associated with an increased risk (P = 0.039), while HLA-DRB1 * 0901 conferred protection from alloimmunization (P = 0.008). HLA Class II locus homozygosity was more frequently observed in the alloantibody-negative group (P = 0.01). These preliminary findings suggest that particular HLA-DR81 alleles and overall homozygosity at HLA class II loci are associated with alloimmunization risk in SCD. If confirmed, HLA type may serve as a useful genetic predictor of alloimmunization risk, and permit a targeted approach to the use of phenotypically matched blood.

Solid-phase photosensitizers based on fullerene C_60 for photodynamic inactivation of viruses in biological liquids

A new type of solid-phase photosensitizer has been proposed and created on the basis of aggregated fullerene C60 for the photodynamic inactivation of pathogens in biological liquids. This paper demonstrates the chief advantage of such solid-phase systems, which is that efficient inactivation of pathogens (using influenza viruses as an example) by active forms of oxygen formed when a photosensitizer is irradiated in aqueous and biological media is combined with high photostability of the fullerene coatings and the possibility of completely extracting the photosensitizer from the biological medium after photodynamic activation.

A phenomenological microscopic view of chemical reactivity of nanocrystalline materials under shear

A phenomenological approach is presented to analyse the reaction kinetics and compare the efficiency of processes driven by mechanochemical and thermal activation. Solid phase systems as well as gas–solid processes are examined: the synthesis of equiatomic CoFe nanostructured solid solution, the hydrogen absorption by Mg 2Ni alloy and the CO hydrogenation over supported CoFe powder catalyst. In spite of the low efficiency of the mechanical processing technique, related to the discontinuous treatment, however, when elementary impact events are taken into account, mechanically activated processes show remarkably higher conversion rate values than their thermal counterparts. Such result can be related to the occurrence of mechanochemical effects.

Guidelines for microplate techniques in liquid-phase blood grouping and antibody screening

Summary. This document is an introduction to microplate serology prepared at a time of very active research and development. Antibody detection techniques are expected to improve during the lifetime of this document. Approximately 25% of hospital blood banks are ABO and D grouping by microplate techniques. Antibody screening by microplate techniques is only being carried out by a small percentage of hospital blood banks but there is likely to be a change to antiglobulin tests by microplate procedures as soon as the methods have been thoroughly tested and approved. There are one or two weak links in these procedures which could give rise to serious errors:— (1) Antiglobulin reagents standardized for spin-tube tests may be subject to prozones in liquid phase microplate tests. Each new batch of antiglobulin reagent must be standardized by the microplate procedure in use to show that the reagent is at its optimum anti-IgG dilution for use. However dilutions greater than 1:2 may seriously compromise the anti-complement activity of the reagent. (2) Automated cell washers for microplates are currently under development and should be evaluated by replicate tests with weak anti-D sensitized cells. (3) The combination of diluted anti-IgG and poor washing procedures may lead to neutralization of anti-IgG and cause false negative errors. Future development for improved antiglobulin tests in microplates by a solid phase system is now well advanced and workers proposing to change to antibody screening by microplates are advised to bear this in mind. It is hoped that microplate methodology will move towards standardization based on national guidelines using standard antibody reagents for the validation of new microplate procedures.

Epitope mapping of the carcinoembryonic antigen by monoclonal antibodies and establishment of a new improved radioimmunoassay system.

A comprehensive mapping of epitopes on the carcinoembryonic antigen (CEA) molecule has been achieved by analyses of the specificities of 146 monoclonal antibodies (MAbs) from more than 300 hybridomas established recently. The reactivities of MAbs were analyzed by radioimmunoassays (RIA) with highly purified preparations of CEA and related antigens including normal fecal antigen-1 (NFA-1), NFA-2 in normal adult feces, nonspecific cross-reacting antigen (NCA) in lung and NCA-2 in meconium. The MAbs could be divided into five groups: group I, 23 clones directed to the NCA-common part of the CEA molecule; group II, 31 clones directed to the normal fecal cross-reacting antigen (NFCA)-common part; group III, 46 clones directed to the NFA-1-common part; group IV, 33 clones reactive with the heterogeneous carbohydrate part; and group V, 13 clones directed to the CEA-distinctive part which seemed to be highly specific for CEA. Mutual inhibitions of CEA binding between MAbs of the individual groups revealed that at least 25 different subgroups can be defined i.e., 4, 7, 8, 4, and 2 subgroups in groups I to V, respectively. The epitopes recognized by the group IV MAbs were found to be sensitive to oxidation with periodate, while the epitopes defined by MAbs of the other groups were resistant to this treatment. A solid-phase sandwich-type RIA system for CEA was established by using 2 MAbs from groups II and III as the CEA catcher and an MAb of group V as the tracer. This assay was shown to exhibit improved cancer-specificity and accuracy in the estimation of serum CEA levels.

Gel‐Phase 13C NMR Spectroscopy of Selected Solid Phase Systems

AbstractStudies on the applicability of conventional liquid‐state NMR spectroscopy for the analysis of solid‐phase organic reactions directly on the resin will be described. For a systematic investigation small and easily assignable molecules substituted with a chain of varying length were synthesized. In a subsequent step these so‐called sensor molecules were attached to commercially available resins. After swelling experiments, 13C NMR spectra of the solid phase systems in gel form were recorded using Composite Pulse Decoupling (CPD) and Attached Proton Test (APT) techniques. The quality of the resulting spectra was analyzed using the half‐height linewidths of the signals as the most important criterion. Based on these data, the parameters to obtain high quality spectra were determined.

Bioremediation of Diesel Fuel Contaminated Soil: Effect of Non Ionic Surfactants and Selected Bacteria Addition

Aim of this work was to evaluate influence of two commercial surfactants and inoculum of selected bacteria on biodegradation of diesel fuel in different systems. Among alkyl polyethossilates (Brij family) and sorbitan derivates (Tween family) a first selection of surfactants was performed by estimation of Koc and Dafnia magna EC50 with molecular descriptor and QSAR model. Further experiments were conducted to evaluate soil sorption, biodegradability and toxicity. In the second part of the research, the effect of Brij 56, Tween 80 and selected bacteria addition on biodegradation of diesel fuel was studied in liquid cultures and in slurry and solid phase systems. The latter experiments were performed with diesel contaminated soil in bench scale slurry phase bioreactor and solid phase columns. Tween 80 addition increased the biodegradation rate of hydrocarbons both in liquid and in slurry phase systems. Regarding the effect of inoculum, no enhancement of biodegradation rate was observed neither in surfactant added nor in experiments without addition. On the contrary, in solid phase experiments, inoculum addition resulted in enhanced biodegradation compared to surfactant addition.

Participation of new active species in epoxidation with cetylpyridinium dodecatungstate/FAp/urea–H 2O 2 system

We have developed an efficient catalytic solid-phase system for epoxidations that uses cetylpyridinium dodecatungstate ((CetylPy) 10[H 2W 12O 42]) catalyst/fluorapatite (FAp) disperse phase with a solid urea–hydrogen peroxide complex (urea–H 2O 2). The solid system was reusable and retained its high catalytic activity, although the catalyst was not fixed on the solid-phase. The reaction rate was first-order with respect to substrate concentration and amount of the catalyst. The solid-phase activation of polyoxometalates with urea–H 2O 2 was studied using FT-IR and solid-state NMR spectroscopy, and no known degraded peroxo-species was observed to form. Based on these kinetic and spectroscopic studies, we propose that the active species is a new, stable peroxo-species with the framework of the parent dodecatungstate, of which the terminal W( O) 2 site is specifically transformed to peroxo-type of W O(O 2), in the system. Much higher efficiency of the dodecatungstate compared with the phsphotungstate or the decatungstate is considered to be due to the non-degraded, site-specific peroxo-species.

Vanadomolybdophosphoric acid/fluorapatite solid-phase system for aerobic oxidative dehydrogenation

We developed a solid-phase-oxidation-system using FAp disperse phase and vanadomolybdophosphoric acid (H 3+ n PV n Mo 12− n O 40: PV n) catalysts with molecular oxygen as a new green reaction system. The PV4/FAp system was an efficient and recyclable solid–catalyst system for solvent-free oxidative dehydrogenation of α-terpinene to p-cymene under 1 atm of molecular oxygen at 50 °C. The catalytic activity in the solid-phase system was comparable to that in the homogeneous liquid-phase system with acetonitrile. Even if under air conditions, PV4/FAp system was able to promote the catalytic dehydrogenation at room temperature sufficiently.

The effect of porphyrin supramolecular structure on singlet oxygen photogeneration

This work is to show that activity of porphyrins in singlet oxygen generation (SOG) is determined not only by their molecular structure but also by supramolecular structure of porphyrin containing systems. This is demonstrated by results of studies of SOG in the gas phase by vacuum deposited tetraphenylporphyrin (TPP) layers under photoexcitation conditions. The structure of the layers was studied by atomic force microscopy (AFM), TEM in diffraction regime (TED) and by the flicker-noise spectroscopy (FNS) method. It was shown that substrates affect the deposited layers structure only at earlier stages of the layer formation. AFM and TED data, together with FNS quantitative parameters of TPP layers, show directly that the chemical activity of solid-phase systems can be determined not only by their chemical nature but also by their supramolecular structure.

Tetrabutylammonium Phosphomolybdate on Fluorapatite: An Efficient Solid Catalyst for Solvent‐Free Selective Oxidation of Sulfides.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Bioremediation of Diethylhexyl Phthalate Contaminated Soil: A Feasibility Study in Slurry- and Solid-Phase Reactors

The aim of the research was to verify the possibility of applying bioremediation as a treatment strategy on a poly(vinyl chloride) (PVC) manufacturing site in the north of Italy contaminated by diethylhexyl phthalate (DEHP) at a concentration of 5.51 mg/g of dry soil. Biodegradation kinetic experiments with DEHP contaminated soil samples were performed in both slurry- and solid-phase systems. The slurry-phase results showed that the cultural conditions, such as N and P concentrations and the addition of a selected DEHP degrading strain, increased the natural DEHP degradation rate. On the basis of these data, experiments to simulate bioventing on contaminated soil columns were performed. The DEHP concentration reached 0.63 mg/g of dry soil in 76 days (89% of degradation). A kinetic equation was developed to fit the experimental data and to predict the concentration of contaminant after treatment. The data obtained are encouraging for a future in situ application of the bioventing technology.