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Heavy metals and chemical oxygen demand (COD) are major challenging pollutants for most electroplating wastewater treatment plants. A novel composite material, prepared with a mixture of calcium and sodium compounds and tailings, was simply mixed by ratios and used to treat a comprehensive electroplating wastewater with influent COD, total copper (T-Cu), and total nickel (T-Ni) respectively as 690, 4.01, and 20.60 mg/L on average. Operational parameters, i.e. the contact time, pH, mass ratio of calcium and sodium compounds and tailings, were optimized as 30 min, 10.0, and 4:2:1. Removal rates for COD, T-Cu, and T-Ni could reach 71.8, 90.5, and 98.1%, respectively. No significant effect of initial concentrations on removal of T-Cu and T-Ni was observed for the composite material. The adsorption of Cu(II) and Ni(II) on the material fitted Langmuir and Freundlich isotherms respectively. Weight of waste sludge from the calcium/sodium-tailing system after reaction was 10% less than that from the calcium-tailing system. The tailing-based composite is costeffective in combating comprehensive electroplating pollution, which shows a possibility of applying the tailings in treating electroplating wastewater. [ABSTRACT FROM AUTHOR]

In this work, we presented a novel evanescent wave absorption sensor based on U-bent tapered multimode fiber covered by molybdenum disulfide (MoS2) film (MoS2@TU fiber EWA sensor). The multimode fiber was manufactured by the fused tapered fiber machine, and then heated using a butane candle flame and bent into a U-bent structure. MoS2 was grown on the fiber directly by thermally decomposing the precursor of (NH4)2MoS4. We have demonstrated that the MoS2 can be applied in the filed of EWA sensor, and the EWA sensor based on U-bent tapered multimode fiber (TU fiber) possessed higher sensitivity than that based on U-bent fiber. The sensitivity (ΔA/ΔC) of the developed EWA sensor is 0.34 in detection of ethanol solution. It shows good sensitivity, linearity, repeatability and stability in detection. And the developed EWA sensor also shows good performance in detection of the adenosine solution, this work shows that the developed EWA sensor may have promising applications in biosensing. [ABSTRACT FROM AUTHOR]

In this work, we have presented a novel local surface plasmon resonance (LSPR) sensor based on the U-bent plastic optical fibre (U-POF). Firstly, a layer of discontinuous silver (Ag) thin film was deposited on the U-POF and then the Ag film was covered by a layer of cladding synthesized by polyvinyl alcohol (PVA), graphene and silver nanoparticles forming the PVA/G/AgNPs@Ag film. The normalized transmittance spectrum of the LSPR sensor have been collected in a range of the refractive index (RI) from 1.330 to 1.3657 in ethanol solution, and 700.3 nm/RIU sensitivity of the developed LSPR sensor has been demonstrated. By experiments, we demonstrated that the graphene could improve the sensitivity of the LSPR sensor and delay the oxidation process of the AgNPs effectively to keep the stability of the LSPR sensor. The LSPR sensor also exhibited good sensitivity and linearity in the detection of glucose solutions. This work shows that the developed LSPR sensor may have promising applications in biosensing. [ABSTRACT FROM AUTHOR]