Preparation and Photocatalytic Properties of LnBaCo<SUB>2</SUB>O<SUB>5+δ</SUB>(Ln = Eu, Gd, and Sm)

A new type of photocatalytic material, double-perovskite oxides, LnBaCo2O5+δ (Ln = Eu, Gd, and Sm) was synthesized via a conventional solid-state reaction process using Ln2O3, BaCO3 and Co2O3 as raw materials. X-ray diffraction results show that the crystalline structures are a pure orthorhombic lattice and are consistent with LnBaCo2O5+δ microparticles. The photocatalytic activity of the LnBaCo2O5+δ (Ln = Eu, Gd, and Sm) powders was further demonstrated in the degradation of Congo red (CR) under ultraviolet light irradiation with the dye solution concentration of 25 or 50 mg·L-1. The double-perovskite oxides LnBaCo2O5+δ show a certain photocatalytic activity during the degradation of CR under ultraviolet light, which means that they are one kind of the promising photocatalytic materials for the degradation of the azo dyes.

Stream Monitoring and Preliminary Co-Treatment of Acid Mine Drainage and Municipal Wastewater along Dunkard Creek Area

This study investigated coal-mine drainage(AMD)and municipal wastewater(MWW)contaminant concentrations and conducted the combined treatment in phases I and II:phase I,evaluating the effects of mixing the two based on the extent of acid neutralization and metals removal;phase II:conducting anaerobic batch reactor treatment of AMD and MWW under varying COD/sulfate ratios(0.04-5.0).In phase I,acid mine drainage water quality conditions are as follows:pH 4.5,acidity 467.5 mg/L as CaCO3,alkalinity 96.0 mg/L as CaCO3,Cl-11.8 mg/L,SO42-1722 mg/L,TDS 2757.5 mg/L,TSS 9.8 mg/L,BOD 14.7 mg/L,Fe 138.1 mg/L,Mg 110.8 mg/L.Mn 7.5 mg/L,Al 8.1 mg/L,Na 114.2 mg/L,and Ca 233.5 mg/L.Results of the mixing experiments indicated significant removal of selected metals(Fe 85~98%,Mg 0~65%,Mn 63~89%,Al 98~99%,Na 0~30%),acidity(77~95%)from the mine water and pH was raised to above 6.3.The Phase II results suggested under the wide range of COD/sulfate ratios,COD and sulfate removal varied from 37.4%-100%and 0%-93.5%respectively.During biological treatment,alkalinity was generated which leads to pH increase to around 7.6-8.5.The results suggested feasibility of the proposed technology for co-treatment of AMD and MWW.A conceptual design of co-treatment system which is expected to remove a matrix of pollutants has been provided to utilize all the locally available water resources to achieve the optimum treatment efficiency.The technology also offers an opportunity to significantly reduce capital and operating costs compared to the existing treatment methodologies used.Featured Application:In this study,we have measured the concentrations of contaminants in acid mine drainage(AMD)and municipal wastewater(MWW)and conducted the combined treatment in phases I and II.This is significant because in previous years there was a massive fish kill that is linked to the high total dissolved solids(TDS)and salinity content in the water.With the current proposed combined treatment technology,it shows high potential in reducing TDS and salinity content in the combined wastewater which will prevent similar accident(Dunkard creek fish kill in 2019)happening again.

A color-based FHGC approach facilities DNA-based clinical molecular diagnostics

The flow-through hybridization and gene chip(FHGC)was developed to used in clinical molecular diagnostics for thalassemia,human papillomavirus(HPV),and other dis-eases.FHGC could improve hybridization efficiency and reduce hands-on time,thus improving precision,repro-ducibility,and traceability.Multiple genotypes can be detected simultaneously without incurring high costs.^(1)During the experiment,the polymerase chain reaction(PCR)product or buffer forced through the membrane matrix,PCR products are apprehended by a probe attached to the membrane.