Ultrahigh ciprofloxacin accumulation and visible-light photocatalytic degradation: Contribution of metal organic frameworks carrier in magnetic surface molecularly imprinted polymers.

Pharmaceuticals pollutions causes inevitable threat for both water environment and human health. However, both the selective and efficient accumulation together with degradation in real wastewater is still one of the major challenges which need further exploration. Here, we designed and synthesized MIL-100 based mesoporous carries supported surface molecularly imprinted polymers. The functional monomer was successfully grafted on the metal organic frameworks (MOFs) carries with magnetic core (Fe3O4). The simultaneous hydrolysis of functional precursor and condensation of the hydrolyzed precursors form a three-dimensional polymer network. Thanks to the high surface area and abundant mesoporous channels formed by the fast microwave irradiation method, it can facilitate mass transfer process and achieve high uptake capacity. This MIL-100 based imprinted polymer showed both ultrahigh selectivity (α(QMIP/QNIP) = 3.54) and highest uptake capacity calculated by the Langmuir equation (273.65 mg/g) for Ciprofloxacin so far. In order to prove the role of MIL-100 insides, pore size distribution, surface area, high angle annular dark field-scanning transmission electron microscopy (HAADF-STEM) images were studied detailly. Adsorption mechanism have been proposed based on X-ray Photoelectron Spectroscopy (XPS) and Infrared Spectroscopy (IR) spectra before and after the treatment. Importantly, the influence of environmental competitors including the inorganic ions and natural organic matters have been evaluated separately. Furthermore, the material can effectively remove targeted compound which was spiked in real secondary effluents from Beijing, substantiating that this novel MOFs-based material is among the rank of excellent CIP adsorbent. Furthermore, the iron-based active sites can be accessible for CIP, resulting the completely degradation under visible - light irradiation with small amount of hydrogen peroxide added. Our study presents a facile approach by introducing MILs to improve the performance of imprinted polymers.

Aryne cycloaddition with 3-oxidopyridinium species.

The [3 + 2] cycloaddition of arynes with 3-oxidopyridinium species is examined using the Kobayashi benzyne precursor. The reaction affords a bicyclo[3.2.1] skeleton under mild conditions. A [7 + 2] cycloaddition mode with a subsequent pyridine ring-opening event has also been observed.

Biological treatment of H(2)S using pellet activated carbon as a carrier of microorganisms in a biofilter.

Biological treatment is an emerging technology for treating off-gases from wastewater treatment plants. The most commonly reported odourous compound in off-gases is hydrogen sulfide (H(2)S), which has a very low odor threshold. This study aims to evaluate the feasibility of using a biological activated carbon as a novel packing material, to achieve a performance-enhanced biofiltration processes in treating H(2)S through an optimum balance and combination of the adsorption capacity with the biodegradation of H(2)S by the bacteria immobilized on the material. The biofilm was mostly developed through culturing the bacteria in the presence of carbon pellets in mineral media. Scanning electron microscopy (SEM) was used to identify the biofilm development on carbon surface. Two identical laboratory scale biofilters, one was operated with biological activated carbon (BAC) and another with virgin carbon without bacteria immobilization. Various concentrations of H(2)S (up to 125 ppmv) were used to determine the optimum column performance. A rapid startup (a few days) was observed for H(2)S removal in the biofilter. At a volumetric loading of 1600 m(3)m(-3)h(-1) (at 87 ppmv H(2)S inlet concentration), elimination capacity of the BAC (181 gH(2)Sm(-3)h(-1)) at removal efficiency (RE) of 94% was achieved. If the inlet concentration was kept at below 30 ppmv, high H(2)S removal (over 99%) was achieved at a gas retention time (GRT) as low as 2s, a value, which is shorter than most previously reported for biofilter operations. The bacteria population in the acidic biofilter demonstrated capacity for removal of H(2)S in a broad pH range (pH 1-7). There are experimental evidences showing that the spent BAC could be re-used as packing material in a biofilter based on BAC. Overall, the results indicated that an unprecedented performance could be achieved by using BAC as the supporting media for H(2)S biofiltration.

Thermoactive extracellular proteases of Geobacillus caldoproteolyticus, sp. nov., from sewage sludge.

A proteolytic thermophilic bacterial strain, designated as strain SF03, was isolated from sewage sludge in Singapore. Strain SF03 is a strictly aerobic, Gram stain-positive, catalase-positive, oxidase-positive, and endospore-forming rod. It grows at temperatures ranging from 35 to 65 degrees C, pH ranging from 6.0 to 9.0, and salinities ranging from 0 to 2.5%. Phylogenetic analyses revealed that strain SF03 was most similar to Saccharococcus thermophilus, Geobacillus caldoxylosilyticus, and G. thermoglucosidasius, with 16S rRNA gene sequence identities of 97.6, 97.5 and 97.2%, respectively. Based on taxonomic and 16S rRNA analyses, strain SF03 was named G. caldoproteolyticus sp. nov. Production of extracellular protease from strain SF03 was observed on a basal peptone medium supplemented with different carbon and nitrogen sources. Protease production was repressed by glucose, lactose, and casamino acids but was enhanced by sucrose and NH4Cl. The cell growth and protease production were significantly improved when strain SF03 was cultivated on a 10% skim-milk culture medium, suggesting that the presence of protein induced the synthesis of protease. The protease produced by strain SF03 remained active over a pH range of 6.0-11.0 and a temperature range of 40-90 degrees C, with an optimal pH of 8.0-9.0 and an optimal temperature of 70-80 degrees C, respectively. The protease was stable over the temperature range of 40-70 degrees C and retained 57 and 38% of its activity at 80 and 90 degrees C, respectively, after 1 h.

Physical and chemical properties study of the activated carbon made from sewage sludge.

Preparation of activated carbon from sewage sludge is a promising way to produce a useful adsorbent for pollutants removal as well as to dispose of sewage sludge. The objective of this study was to investigate the physical and chemical properties of the activated carbon made from sewage sludge so as to give a basic understanding of its structure. The activated carbon was prepared by activating anaerobically digested sewage sludge with 5 M ZnCl2 and thereafter pyrolyzing it at 500 degrees C for 2 h under nitrogen atmosphere. The properties investigated in the present study included its surface area and pore size distribution, its elemental composition and ash content, its surface chemistry structure and its surface physical morphology. Furthermore, its adsorption capacities for aqueous phenol and carbontetrachloride were examined. The results indicated that the activated carbon made from sewage sludge had remarkable micropore and mesopore surface areas and notable adsorption capacities for phenol and carbon-tetrachloride. In comparison with commercial activated carbons, it displayed distinctive physical and chemical properties.