[Removal of Oxytetracycline from Water Using Blast Furnace Slag Loaded Sulfide Nanoscale Zero-valent Iron].

Blast furnace slag loaded with sulfide nano zero valent iron (S-nZVI@BFS) was applied to remove oxytetracycline (OTC) from water. S-nZVI@BFS was synthesized via liquid reduction and characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Brunauer, Emmett and Teller (BET) theory. The effect of reaction time, initial concentration of OTC, initial pH, and coexisting hexavalent chromium[Cr(Ⅵ)] were investigated. The results show that Fe and S were successfully immobilized on the surface of S-nZVI@BFS, the specific surface area and pore volume of which increased to 141.986 m2·g-1 and 0.388 cm3·g-1, respectively, following the loading of nZVI and sulfurization. The utilization rate of the surface active sites of S-nZVI@BFS was improved with an increase of the initial concentration of OTC; the removal rate increased from 20.12 mg·g-1 to 202.74 mg·g-1 when the initial concentration of OTC was increased from 10 mg·L-1 to 100 mg·L-1. The removal rate decreased with pH, declining from 99.78 mg·g-1 to 41.12 mg·g-1 when pH was increased from 3 to 11 due to the switch from Fendon oxidation to electrostatic adsorption. There was notable competition between OTC and Cr(Ⅵ) meaning that Cr(Ⅵ) can inhibit the removal of OTC, which is dose dependent.

[Water treatment efficiency of constructed wetland plant-bed/ditch systems].

Shijiuyang constructed wetland (SJY-CW) in Jiaxing City adopted plant-bed/ditch systems originated from the natural landscape as its major functioning unit. The constructed root channel technology (CRCT) is the core technique applied within the plant-bed/ditch systems. Monitoring results demonstrated that the wetland had the capability of improving water quality indexes by one rank grade according to the national environmental quality standards for surface water (GB 3838-2002). In order to optimize the water quality improvement function of plant-bed/ditch systems and CRCT, a pilot project in SJY-CW was constructed from May to October, 2010. The project contained 16 independent experimental cells. Orthogonal test design was applied to probe into the effects of constructed root channel layers, plant species combination, and reinforced physical substrates on promoting the water quality amelioration efficiency of the plant-bed/ditch systems. Comprehensively considering water treatment effects, construction difficulty, and construction and maintenance cost, the recommended optimal ways are as follows. Plant straws were preferably paved under subsurface zones by two layers with a gap of 20-30 cm. The preferable plant combination was reed (Phragmites australis) plus wild rice (Zizania caduciflora). Calcite might be applied as alternative reinforced media in some suitable sites of plant-bed/ditch systems. Water treatment effects were compared between pilot project and the whole wetland area of SJY-CW. The results showed that the reinforced pilot project exhibited higher treatment efficiency for nutrients than SJY-CW itself. The removal rates of total nitrogen, total phosphorus, and ammonia nitrogen were increased by about 20% - 40% in the pilot project. This suggested that SJY-CW could release its vast water treatment potential by means of increasing water flux through the subsurface root channel zones of plant beds. Therefore, some adjustment and control measures could be proposed to maintain the tradeoff balance between the potential release and maximization of wetland treatment efficiency and the treated water amount, such as constructing or modifying the hydraulic structures to regulate flow amount through large ditch, redistributing water flow and increasing the water head difference between the two sides of alternate small ditches.

A simple and rapid fluorimetric method for simultaneous determination of protoporphyrin IX and zinc protoporphyrin IX in whole blood.

Derivative variable-angle synchronous fluorescence (DVASF) spectrometry improves the spectral resolution and selectivity of the fluorescence method. The feasibility of DVASF spectrometry for the simultaneous determination of protoporphyrin IX (PP) and zinc protoporphyrin IX (ZnPP) was investigated. PP and ZnPP were distinguished from each other simultaneously and rapidly by the DVASF method. The spectra were resolved well, and the two components were determined in a single scan, avoiding the spectral compensation factor for PP and chromatographic separation. The linear range of the calibration curve for PP was from 0.190 to 152 nmol/L and for ZnPP was from 0.383 to 230 nmol/L. The detection limits of PP and ZnPP were 0.098 nmol/L and 0.088 nmol/L, respectively. The within-run imprecision (RSD, n = 5) for PP was 4.1%, and for ZnPP was 4.2%. Mean recoveries (SD) of PP and ZnPP added to a blood sample were 86.4 (7.3)% and 72.9 (6.6)%, respectively. This method should be a potential tool in the rapid routine screening of large quantities of samples.