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Wet oxidation (WO) is a well established process for purification of concentrated municipal and industrial wastewaters. Many attempts have been made to modify the WO process or to create a suitable combination of processes. This work was undertaken to investigate wet oxidation integrated with coagulation, i.e. to treat the sludge remaining after coagulation with a WO process. The possibility of regeneration of the used coagulant was also considered. Two waters from paper mills were used: TMP (thermomechanical pulp) circulation water and membrane concentrate. About 50% of the COD in the original water can be removed by coagulation using Fe2(SO4)3. The results from the wet oxidation experiments show the positive effect of iron in the chemical sludge as a catalyst. The efficiency of the WO process was enhanced almost by 100%. The remaining dissolved organic matter can be easily removed biologically.

In this paper, the performance of a photoassisted electrolysis process, for the degradation of organic pollutants, is investigated. Results obtained in this work have shown that the thermally prepared anode of titanium, coated with 70TiO2/30RuO2, exhibits photoactivity and may be used for the treatment of effluents. A synthetic phenol aqueous solution and a real paper mill industry effluent were treated. Kinetic analysis showed a synergetic effect of electrolysis and photocatalysis and degradation rates are an order of magnitude greater than the sum of the results reached by using both processes individually. Using a 125 W mercury bulb and 20 mA cm-2, the phenol concentration decayed 85% in 90 min and 70% reduction of TOC was obtained. In the application of the treatment process for the degradation of the E1 bleach Kraft mill effluent, total phenols were practically eliminated in a short period of processing time, and color, usually resistant to biological treatment, was reduced to 10% from its initial value measured in terms of absorbance. Reductions of AOX, COD, and BOD by 25%, 30%, and 35%, respectively, were also observed.

Characteristics and catalytic properties of a series of carbon-based catalysts (CBCs) produced from paper mill sludge were evaluated. The major processes involved in the production of the catalysts were chemical activation, impregnation, pyrolysis, and post pyrolysis rinsing. The porous structure, catalytic activity and thermostability of the catalysts were tailored during the production stage by introducing hetero-atoms (zinc chloride, and ferric nitrate) in the carbon structure. Characterization of the produced CBCs included determination of the surface area, pore size, and pore size distribution (PSD) from standard N2-adsorption isotherm data. The extent of graphitization and the presence of metal crystals were identified from X-ray diffraction (XRD). The limit of the catalyst gasification was estimated from thermogravimetric analysis (TGA) conducted in an oxidized environment. The NOx reduction capability of the produced catalysts was evaluated in the presence of carbon monoxide using a fixed bed reactor. The reaction temperature ranged from 300 to 500 degrees C. It was shown that paper mill sludge is an excellent precursor for the production of CBCs with NOx removal capability of 66-94%. The catalytic capability of the produced CBCs varied according to the method of production, catalyst surface properties (surface area, pore structure, PSD), metal composition and reaction temperature. The highest NOx removal capacity was observed for the catalytic reactions carried out at 400 degrees C. The mesoporous catalyst produced with a Zn:Fe molar ratio of 1:0.5 exhibited the maximum NOx removal catalytic activity of 94%.

A cellulose bleaching effluent (E1) was degraded in batch conditions by photocatalysis using TiO2 and ZnO supported on glass Raschig rings. The effluent was completely decolourised and the total phenol content was reduced by 85% after 120 min treatment with both catalysts. Partial mineralization of the organic matter was confirmed by total organic carbon (TOC) reduction, approximately 50%. The residual organic matter shows a low acute toxicity as compared to the initial values and AOX values are strongly reduced after the photocatalytic oxidation. Molecular mass distribution showed that high molecular mass compounds were almost completely degraded.

The oxidation of a 186 ppm 6-chlorovanillin solution was performed using impregnated TiO2 glass rings in a 1 l photochemical reactor. Fifty per cent degradation was obtained after 60 min with recirculation of the solution. Then, oxidised samples were submitted under aerobic conditions to bacterial degradation in the Pseudomonas paucimobilis (S37) and Burkholderia cepacia (PZK). Both selected aerobic bacteria degrade more efficiently the photocatalysed samples, being PZK strain better than S37. A first-order kinetic was observed in both systems photocatalytic and bacterial degradation.

A simple and sensitive 3D origami multiple electrochemiluminescence immunodevice based on a novel silver nanoparticles modified porous paper working electrode as a sensor platform and multi-labeled nanoporous gold-carbon spheres as tracers has been demonstrated for the first time.

In this report, hierarchical ZnO nano- and microstructures were directly grown for the first time on a bacterial cellulose substrate and on two additional different papers by hydrothermal synthesis without any surface modification layer. Compactness and smoothness of the substrates are two important parameters that allow the growth of oriented structures.

A simple and sensitive 3D microfluidic origami multiplex electrochemical immunodevice was developed for the first time using a novel nanoporous silver modified paper working electrode as a sensor platform and different metal ion functionalized nanoporous gold-chitosan as a tracer.

Surface sol-gel process was used to replicate the hierarchical morphology of natural cellulosic substances with nanometer precision. The resultant artificial fossils are ceramic nanomaterials composed of metal oxide nanotubes.

A high-throughput, simple, fast, low-cost and sensitive paper-based electrochemical immunodevice has been demonstrated based on a functionalized 3D paper-based device for point-of-care diagnosis.

Paper strips containing DNA-conjugated microgels (MG) are used to achieve sensitive DNA detection in three steps: target DNA promoted ligation of a DNA primer to the MG-bound DNA, rolling circle amplification (RCA) between the primer and a circle DNA, and hybridization of the RCA products and a fluorescent DNA probe.

Cellulose esters of both alkyl and aryl carboxylic acids have been prepared and tested as noncovalent adsorbents for enzymes. Phenoxyacetyl cellulose strongly bound all 10 of the enzymes tested. The bound enzymes, which were not desorbed by 1 m (NH4)2SO4 or moderate (25–50%) concentrations of nonaqueous solvents but which were at least partially desorbed by solutions containing nonionic detergents, usually exhibited nearly complete retention of catalytic activity. Other materials, paper, string, cotton, and glass beads, have been analogously derivatized with similar results. This simple and effective technique warrants consideration for applications in enzyme immobilization.

Organic artefacts degrade by a number of mechanisms. Autoxidation is one of the most important and involves free radicals. The importance of free radical reactions in the degradation of paper and other cellulosic materials, rubber and other organics is described. In the case of paper, treatment with calcium and magnesium compounds can inhibit oxidation, while transition metals increase the rate. Antioxidants have not been used a great deal due to unwanted side effects. The Russell effect, a technique for detecting oxidation using photographic materials, is described.

FDP aldolase has been purified and crystallized from the muscle of codfish. The specific activity of the codfish enzyme was found to be two-thirds that of rabbit muscle aldolase. Other catalytic properties, the molecular weight, and the carboxyl-terminal structure were similar to those of rabbit muscle aldolase. A tryptic peptide containing the Schiff base-forming lysine (1) has been isolated and its primary structure determined as: Ala-Leu-Ser-Asp-His-His-Val-Tyr-Leu-Gln-Gly-Thr-Leu-Leu-βGlys-Pro-Asn-Met-Val-Thr-Ala-Gly-His-Ser-CMCys-Ser-His-Lys. Extensive homology observed in this region of the aldolase molecules isolated from biologically divergent sources indicates the importance of this structure for catalysis of the aldolase reaction.

Four different 1-aminocyclohexanes bearing a tethered thioxanthone group in the 2-position were prepared. The synthesis commenced with the respective N-protected β-amino acids, the carboxyl group of which was employed for the introduction of the thioxanthone moiety. After construction of the thioxanthone and protecting group removal, the conversion of the amino group into the respective thiourea was accomplished by treatment with N-3,5-bis(trifluoromethyl)phenyl isothiocyanate and yielded the title compounds in which the thioxanthone resides in different spatial positions relative to the thiourea motif. Overall yields varied between 20–35%.

This paper describes the organosolv delignification of depithed bagasse using glycerol–water mixtures without a catalyst. The experiments were performed using two separate experimental designs. In the first experiment, two temperatures (150 and 190 °C), two time periods (60 and 240 min) and two glycerol contents (20% and 80%, v/v) were used. In the second experiment, which was a central composite design, the glycerol content was maintained at 80%, and a range of temperatures (141.7–198.3 °C) and time (23–277 min) was used. The best result, obtained with a glycerol content of 80%, a reaction time of 150 min and a temperature of 198.3 °C, produced pulps with 54.4% pulp yield, 7.75% residual lignin, 81.4% delignification and 13.7% polyose content. The results showed that high contents of glycerol tend to produce pulps with higher delignification and higher polyoses content in relation to the pulps obtained from low glycerol content reactions. In addition, the proposed method shows potential as a pretreatment for cellulose saccharification.

SummaryIn this paper we report a method via which enzymatically active products formed during prothrombin activation can be detected by simple photographic means after SDS-gel electrophoresis, blotting onto a nitrocellulose membrane and visualization with the chromogenic substrate, S2238. After amidolytic detection the same nitrocellulose membrane can also be used for immunologic detection of prothrombin activation products, thus allowing a complete description of product formation during prothrombin activation.The detection limit of the so-called “amidoblot” is approximately 3 ng thrombin per gel sample which is comparable to the sensitivity of immunoblotting.It is further shown that the amidoblot technique can also be applied to other coagulation factors for which a suitable chromogenic substrate is available (factor XIIa, kallikrein, factor XIa, factor Xa, plasmin and activated protein C).

The reaction of phosphorothioate with bovine pancreatic ribonuclease at pH 9.0 in the absence of urea led to a derivative, denoted 4PS-ribonuclease, in which two of the four disulphide bonds in the molecule were opened. 4PS-ribonuclease is a unique molecular species, and not a mixture of native and open-chain ribonuclease; this is apparent from electrophoretic studies. By the use of the “diagonal map” technique it has been established unequivocally that the disulphide bonds opened were between half-cystines 3–8 and 4–5, counting from the amino terminus along the ribonuclease chain. 4PS-ribonuclease is fully active enzymically toward RNA, and more active than the native enzyme toward cytidine 2′,3′-cyclic phosphate. It is indistinguishable from native ribonuclease in its immunological reaction with antiserum to ribonuclease, and in its spectrophotometric titration, which shows that three of the six tyrosine phenolic groups in 4PS-ribonuclease titrate abnormally. Unlike native ribonuclease, 4PS-ribonuclease is digested by trypsin, even though at a lower rate than open-chain ribonuclease.