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Internal circulation（IC） denitrification reactor was designed on the basis of IC anaerobic reactor，and the engineering application was investigated for the reverse osmosis concentrated water treatment. The results showed that the IC denitrification reactor exhibited a rapid start and stable running. The effluent TN ranged from 1.89 mg/L to 14.0 mg/L with an average of 4.65 mg/L when the influent TN were from 18.7 mg/L to 39.0 mg/L with an average of 26.6 mg/L，which was lower than the required 15 mg/L by Standard B of Table1 in Comprehensive Wastewater Discharge Standards for the Yellow River Basin in Shanxi Province （DB 61/224-2018）. The effluent suspended solids mass concentration was lower with an average mass concentration of 18.6 mg/L，and the effluent COD of the subsequent recirculation biofilter was 35.4 mg/L，stably controlled below 50 mg/L，which showed a perfect comprehensive treatment effect. Moreover，the IC denitrification reactor had a small footprint，simple process，and a direct water treatment cost of 1.36 yuan/m3，which had significant economic benefits.

Epoxy-functionalized ethylene-octene copolymer (POE-g-PGMA) was prepared by 60Co γ-ray radiation, and polyamide 6/polyethylene-octene blend (PA6/POE) containing POE-g-PGMA was prepared by twin-screw melt extrusion. In this study, the mechanical properties, thermal properties, surface morphology, interfacial compatibility, and water absorption properties of PA6/POE blends with added POE-g-PGMA were investigated. The results showed that GMA was successfully grafted on POE by γ-ray radiation. The morphological analysis showed that the addition of POE-g-PGMA enhanced the dispersion of POE particles in the PA6 matrix. In particular, it demonstrated that with the addition of POE-g-PGMA, pure PA6 has good interfacial compatibility with POE. The results of the Molau test confirmed the compatibilization reactions between POE-g-PGMA and PA6. The thermal analysis showed that the addition of POE and POE-g-PGMA in the dispersed phase had negligible effect on the melting behavior of PA6; however, the crystallization temperature of PA6 improved by approximately 18 °C during the cooling crystallization process, and the crystallinity increased by approximately 4.5%. Furthermore, the impact strength of the compatibilized PA6/POE blend was significantly higher than that of the PA6/POE blend, with the highest value of impact strength obtained at a POE-g-PGMA content of 3% being approximately 2.75 times greater than that of pure PA6 under the experimental conditions.

A super absorbent polymer (SAP) was prepared using starch and acrylic acid under exposure to 60Co γ-rays irradiation. The chemical structure of the SAP was characterized by Fourier-transform infrared spectroscopy Scanning electron micrographs showed that the surface of the SAP contained numerous mesoporous structures. Thermogravimetric analysis indicated improved thermal stability of the SAP compared to that of the original starch. The absorbed dose and feed ratio of the acrylic acid and starch significantly affected the water absorption performance of the SAP. The water absorption capacity of the SAP was 532 g/g at the optimal conditions (absorbed dose: 20 kGy, crosslinking agent: 80 mg/L, feed ratio of starch to acrylic acid: 1/2). The SAP efficiently released the loaded KNO3 or Na3PO4; the release rates were 82% for K+ and 80% for PO43-.

A super absorbent polymer (SAP), sodium lignosulfonate (LS)/sodium carboxymethyl cellulose (CMC), was produced from LS and CMC through the irradiation of γ-rays. The effects of the absorbed dose and LS dosage on the water absorption performance of the SAP were investigated. The ultraviolet (UV) resistance of the SAP was also evaluated. The surface morphology, chemical structures, and thermal weightlessness of the SAP were characterized using scanning electron microscopy, Fourier-transform infrared spectroscopy, and thermogravimetric analysis, respectively. The optimal conditions for preparing the SAP were as follows: 20 g of CMC, 1 g of LS, 100 g of water, and 15 kGy of absorbed dose. The water absorption capacities of the prepared SAP were 316.1 g/g and 97.1 g/g for deionized water and 0.9% NaCl solution, respectively. Therefore, the water absorption capacity improved with the addition of LS. Moreover, after irradiation with a 365-nm-wavelength UV lamp (16 W) for 15 d, the water absorption capacity (deionized water) of the LS1/CMC SAP was 276 g/g, while that of the LS0/CMC SAP decreased from 259.3 g/g to 176.7 g/g. Finally, the as-prepared SAP exhibited outstanding UV resistance.

Herein, a bifunctional nonwoven fabric sorbent containing thioamide and carboxyl groups was synthesized via radiation grafting of acrylonitrile and acrylic acid, followed by modification with sodium sulfide, to selectively recover Au(Ⅲ) from the acidic solution. A polyethylene/polypropylene skin-core-structured nonwoven fabric was used as the substrate. The structure and properties of the sorbent were characterized using infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, energy dispersive spectroscopy, contact angle measurements, X-ray photoelectron spectroscopy, and X-ray diffraction. The adsorption performance of the sorbent was determined through batch adsorption tests. The results indicated that the sorbent exhibited excellent Au‍(Ⅲ) adsorption capacity over a wide pH range (2-7) and demonstrated good selectivity for Au(Ⅲ) in the presence of coexisting metal ions, with selectivity coefficients ranging from 55.00 to 2 429.17 and a gold recovery ratio of 98.5%. The adsorption followed the pseudo-second-order kinetic and Langmuir isotherm models, with an Au(Ⅲ) saturation adsorption capacity of 133.91 mg/g. Au(Ⅲ) could be reduced to crystalline Au(0) during the adsorption process. Moreover, the modified nonwoven fabric could be effectively removed via simple high-temperature treatment, facilitating Au recovery.

Bisphenol A epoxy resin was irradiated in air by a 1.5 MeV electron beam accelerator at dose rates of 18 kGy/h and 2 250 kGy/h to achieve the total absorbed doses of 135 kGy, 270 kGy, 500 kGy, and 1 000 kGy. The effects of the dose rates and the absorbed doses on the surface morphology, chemical structure, and thermal properties of the epoxy resin were systematically investigated. The results showed that high dose rates induced vein-like cracks in the epoxy resin, while the total absorbed dose significantly affected the thermal stability and mechanical properties of the resin. Moreover, the epoxy resin exhibited a radiation cross-linking tendency at low absorbed doses, while radiation degradation dominated at high doses. An electron spin resonance analysis indicated that the free radical signals generated during the irradiation were from alkyl radicals and peroxy radicals. The concentration of free radicals was positively correlated with the absorbed dose. Furthermore, the stability of the free radicals in air was studied. The concentration of the generated free radicals reached a plateau at longer storage times.

Starch-based super absorbent polymers (SAPs) were prepared using the gamma-ray co-irradiation method, where two comonomers were grafted and cross-linked. Incorporation acrylamine (AM) and 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) into the SAP was confirmed using Fourier transform infrared spectroscopy. The thermal decomposition behavior of the SAP was studied using thermogravimetric analysis. The salt tolerance was significantly improved by introducing AM and AMPS monomers into the SAP. The absorption rate of the SAP with AMPS in normal saline increased from 46 g/g (without AMPS) to 81 g/g when the ratio of AA:AMPS was 3:1.

The post-radiation effect of three kinds of disposable medical protective clothing made of polyethylene terephthalate/polyurethane (PET/PU), polypropylene/polyethylene (PP/PE), and polyethylene (PE) after radiation sterilization and the effects of radiation on the properties of protective clothing were investigated. The changes in surface morphology, hydrophilicity, mechanical properties, and free radicals of medical protective clothing materials after radiation sterilization were systematically studied using scanning electron microscopy (SEM) and electron spin resonance (ESR) spectroscopy, and by examining the surface contact angle and tensile properties at break. The results showed that the surface morphology of protective clothing made of PET/PU, PP/PE, and PE undergoes no obvious change after γ-ray irradiation. However, the hydrophobicity of the surfaces—whose contact angles were reduced by 2.8%, 7.9%, and 17.8%, respectively—decreased. γ-ray irradiation has little effect on the tensile properties of PET/PU at the sterilizing dose (≤ 50 kGy). On the other hand, the tensile breaking strength and elongation at break of PP/PE and PE protective clothing decreased with the increasing absorbed doses. The signal intensity of free radicals produced by PP/PE and PE protective clothing increased with the absorbed dose and the concentration of free radicals decreased rapidly with the storage time and tended to stabilize after one month.

A novel amidoximated polyethylene nonwoven fabric (PE-g-AO) was successfully prepared by electron beam pre-irradiation grafting with glycidyl methacrylate, followed by reaction induced of ethylenediamine and maleic anhydride, AIBN-initiated polymerization of acrylonitrile, and finally, amidoximation. The chemical structure and morphology of the PE nonwoven fabric before and after modification were characterized by total reflection infrared spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy. Adsorption experiment results showed that the adsorption capacity of PE-g-AO for uranium is 71.92 mg/g (U(VI): 20 mg/L; NaF: 2.0 g/L; sorbent dosage: 0.2 g/L; adsorption time: 216 h). When the dosage of adsorbent is 1.0 g/L, the uranyl ions in the solution are basically adsorbed, and the residual uranium concentration is 0.04 mg/L, which meets the national emission standard. Furthermore, the material has a good adsorption selectivity for uranium in a solution containing UO22+, Ca2+, Mg2+, K+, and Na+ ions.

BackgroundCyclic olefin copolymer (COC), synthesized by catalytic copolymerization of ethylene and norbornene, can be applied in medical devices and drug packaging, owing to its many outstanding properties such as good light transmittance, water vapor barrier and biocompatibility. When this type of medical devices or drug package is sterilized by high energy irradiation, COC will inevitably undergo changes such as radiation scission, oxidation, discoloration and so on. It is of great significance to explain the performance change of COC from the free radical reaction initiated by ionization radiation for the radiation sterilization application of COC medical supplies.PurposeThis study aims to investigate radiation effect of COC in the dose range of radiation sterilization.MethodsEffects of γ-rays on chemical structure, free radical, glass transition temperature, thermal stability, molecular weight distribution, surface properties and melt index of the irradiated COC with the sterilization dose were investigated by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), ultraviolet-visible absorption spectroscopy (UV-vas), electron spin resonance spectroscopy (ESRS), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), gel permeation chromatography (GPC), water contact angle (WCA) and melt mass-flow rate measurement.ResultsThe concentration of free radicals produced by COC irradiation in air increases linearly with the increase of absorbed dose. With the increase of absorbed dose, radiation degradation is dominant, hence the average molecular weight of the radiation oxidation products include carbonyl and hydroxyl compounds decreases, and the surface hydrophilicity is enhanced whilst the melt index is increased.ConclusionsThe molecular chain breakage caused by radiation and the reaction between free radicals and oxygen are the main causes of COC degradation.

Abstract Background Improved understanding of the interactions between bone cells and endothelial cells involved in osteogenesis should aid the development of new strategies for bone tissue engineering. The aim of the present study was to determine whether direct communication between bone marrow stromal cells (MSC) and human umbilical vein endothelial cells (EC) could influence the osteogenic potential of MSC in osteogenic factor-free medium. Methods After adding EC to MSC in a direct-contact system, cell viability and morphology were investigated with the WST assay and immnostaining. The effects on osteogenic differentiation of adding EC to MSC was systematically tested by the using Superarray assay and results were confirmed with real-time PCR. Results Five days after the addition of EC to MSC in a ratio of 1:5 (EC/MSC) significant increases in cell proliferation and cellular bridges between the two cell types were detected, as well as increased mRNA expression of alkaline phosphatase (ALP). This effect was greater than that seen with addition of osteogenic factors such as dexamethasone, ascorbic acid and β-glycerophosphate to the culture medium. The expression of transcription factor Runx2 was enhanced in MSC incubated with osteogenic stimulatory medium, but was not influenced by induction with EC. The expression of Collagen type I was not influenced by EC but the cells grown in the osteogenic factor-free medium exhibited higher expression than those cultured with osteogenic stimulatory medium. Conclusion These results show that co-culturing of EC and MSC for 5 days influences osteogenic differentiation of MSC, an effect that might be independent of Runx2, and enhances the production of ALP by MSC.