Effects of thiamine on treatment performance of textile wastewater

Textile wastewater is commonly treated with activated sludge process technology. However, its treatment performance has not been demonstrated to be very effective. In this study, the effects of micronutrient thiamine on removal efficiencies of dissolved organic carbon (DOC) and chemical oxygen demand (COD) of textile wastewater in a batch test, together with its effect on the oxygen uptake rate (OUR) of activated sludge, were evaluated. Significant improvements were observed in the removal rates of DOC, COD and OUR with 121%, 156% and 121% of those of the control, respectively, when 0.5-2.0 mg/L thiamine was added to the wastewater treatment system. Thiamine could be probably used to improve the treatment performance of textile wastewater.

Effects of micronutrients on biological treatment efficiency of textile wastewater

Micronutrients play a very important role in biological processes for wastewater treatment. Many industrial wastewaters lack in nutrients (macronutrients and micronutrients) required for microbial growth, and this is one of the main problems at many activated sludge plants treating industrial wastewater. The microbial community structure is one of the important factors controlling the pollutant-degrading capacity of biological wastewater treatment system. In this study, the concentrations of micronutrients of the textile wastewater discharged from a textile plant were determined, and the effects of micronutrients on treatment efficiency and microorganism community structure of the biological treatment system were studied. The results showed that the optimal concentrations of magnesium, molybdenum, zinc, thiamine and niacin in the textile wastewater were 5.0, 2.0, 1.0, 1.0 and 1.0mg/L, respectively. The COD removal rates when magnesium, molybdenum, zinc, thiamine and niacin were added individually to the wastewater in their optimal concentrations were 1.8, 1.4, 1.3, 1.6 and 2.2 times of that of the control, respectively. The improving effects of combinations of zinc and thiamine, zinc and niacin, thiamine and niacin were better than single micronutrient. The diversity of quinones (DQ) changed significantly after the micronutrient was added into the wastewater treatment system. This indicated that there was probably a feasibility of optimizing the biological treatment performances and microorganism community structure of textile wastewater treatment system through micronutrient supplement.

Novel passive launch scheme for ultimate bandwidth improvement of graded-index multimode fibers

We propose a new practical multimode fiber optical launch scheme, providing near single mode group excitation for >5 times transmission bandwidth improvement. Equalization-free transmission of a 10-Gb/s signal over 220-m fiber is achieved in experimental demonstrations. © 2010 Optical Society of America.

Micronutrient niacin addition to enhance biological treatment of textile wastewater

Micronutrients play an important role in biological processes for wastewater treatment. Many industrial wastewaters lack in nutrients required for microbial growth, and this is one of the problems at many activated sludge plants treating them. In this study, the effects of the micronutrient niacin on the COD removal rates of textile wastewater, together with the effect of Mixed Liquor Suspended Solids (MLSS) on niacin, were studied. Certain improvement effects were found on the removal rates of COD, when 0.5 similar to 2.0 mg/L niacin was added to the textile wastewater. The optimal concentration of niacin was 1.0 mg/L, which was continuously added during textile wastewater treatment, and removal rates were 1.31 times compared to those of the control system. The concentration of MLSS was probably one of the factors influencing treatment efficiency, and the biological performance of treatment system could be optimized through micronutrient niacin supplements.

Environmental signals: Synthetic humic substances act as xeno-estrogen and affect the thyroid system of Xenopus laevis

According to outdated paradigms humic substances (HS) are considered to be refractory or inert that do not directly interact with aquatic organisms. However, they are taken up and induce biotransformation activities and may act as hormone-like substances. In the present study, we tested whether HS can interfere with endocrine regulation in the amphibian Xenopus laevis. In order to exclude contamination with phyto-hormones, which may occur in environmental isolates, the artificial HS 1500 was applied. The in vivo results showed that HS 1500 causes significant estrogenic effects on X. laevis during its larval development and results of semi-quantitative RT-PCR revealed a marked increase of the estrogenic biomarker estrogen receptor mRNA (ER-mRNA). Furthermore, preliminary RT-PCR results showed that the thyroid-stimulating hormone (TSH beta-mRNA) is enhanced after exposure to HS1500, indicating a weak adverse effect on T3/T4 availability. Hence, HS may have estrogenic and anti-thyroidal effects on aquatic animals, and therefore may influence the structure of aquatic communities and they may be considered environmental signaling chemicals. (c) 2005 Elsevier Ltd. All rights reserved.

Sol-gel method for the preparation of solid-phase microextraction fibers

A novel sol-gel method is applied for the preparation of solid-phase microextraction (SPME) fibers. Scanning electron microscopy experiments suggested a porous structure for the poly(dimethylsiloxane) (PDMS) coating. SPME-GC analysis provided evidence that the sol-gel fibers have some advantages, such as high thermal stability, efficient extraction rates, high velocities of mass transfer, and spacious range of application.

Dispersion-compensating photonic crystal fibers with special characteristics

Based on the modified dual core structure, three kinds of special photonic crystal fibers are presented, which are extremely large negative dispersion, super-broad bond, and large area made field dispersion-compensating photonic crystal fibers (DCPCF). For extremely large negative dispersion DCPCF, the peak of negative dispersion reaches -5.9 x 10(4) ps/(mn km). Super-broad bond DCPCF has broadband large negative dispersion and the dispersion value varies linearly from -380 ps/(nm km) to -420 ps/(nm km) in the C band. The designed large area made field DCPCF has a peak dispersion of -1203 ps/(nm km) with the inner core mode area of 47 mu m(2) and outer core mode area of 835 mu m(2). Furthermore, for the large area mode field DCPCF, the experimental result is also obtained. (C) 2008 Wiley Periodicals, Inc.

A method for analyzing the coupling of 3-D tapered rib waveguides with fibers

The fields in 3-dimensional tapered waveguides are unstable compared with the fields in the straight waveguides. In the case of waveguide-to-fiber coupling and fiber-to-waveguide coupling, a sequence of short straight waveguides has been modeled to approximate the 3-dimensional tapered waveguide; and the unstable incident and reflected fields, as well as their derivatives, were determined by the beam propagation method(BPM). Then free space radiation mode(FSRM) was employed to calculate the reflected and transmitted powers. Analysis results of the coupling of fiber with silicon-on-insulator(SOI) tapered rib waveguides showed the feasibility of the method.

Conversion of Soybean oil to Biodiesel Fuel with Immobilized Candida Lipase on Textile Cloth

The characteristic of biodiesel fuel production from transesterification of soybean oil is studied. The reactant solution is the mixture of soybean oil, methanol, and solvent. A new lipase immobilization method, textile cloth immobilization, was developed in this study. Immobilized Candida lipase sp. 99-125 was applied as the enzyme catalyst. The effect of flow rate of reaction liquid, solvents, reaction time, and water content on the biodiesel yield is investigated. Products analysis shows that the main components in biodiesel are methyl sterate, methyl hexadecanoate, methyl oleate, methyl linoleate, and methyl linolenate. The test results indicate that the maximum yield of biodiesel of 92% was obtained at the conditions of hexane being the solvent, water content being 20 wt%, and reaction time being 24 h.

Micro Fabry-Perot interferometers in silica fibers machined by femtosecond laser

Micro Fabry-Perot (F-P) interferometers (MFPIs) are machined in a single-mode fiber (SMF) and a photonic crystal fiber (PCF) by using a near-infrared femtosecond laser, respectively. The strain and temperature characteristics of the two MFPIs with an identical cavity length are investigated and the experimental results show that the strain sensitivity of the PCF-based MFPI is smaller than that of the SMF-based MFPI due to their different waveguide structures, while the two MFPIs have close temperature sensitivities which are much smaller than that of an in-line SMF etalon sensor reported previously. These MFPIs in silica fibers are compact, stable, inexpensive, capable for mass-production and easy fabrication, offering great potentials for wide sensing applications. (c) 2007 Optical Society of America.

SBS-based slow light in optical fibers: optimum design considerations for undistorted slow-light signal propagation in steady-state and transient regimes

SPIE

Liquid-filled microstructured polymer fibers as monolithic liquid-core array fibers

Liquid-filled microstructured polymer optical fibers (MPOFs) as monolithic liquid-core array fiber are proposed and prepared by injecting high-refractive-index liquid into the holes array of the MPOFs. One example for potential applications is demonstrated as a new kind of coherent imaging fiber. It provides great potential for applications in chemical sensing, biosensors, and endoscopy, particularly in bifunctional detection. (C) 2009 Optical Society of America