Laccase immobilized onto poly(GMA-MAA) microspheres for p-benzenediol removal from wastewater.

Enzymes have already been extensively applied to degrade various organic pollutants in industrial wastewater, and how to improve the stability and reusability of the enzymes is critical to their practical application. In this study, poly(glycidyl methacrylate-methacrylic acid), poly(GMA-MAA), microspheres were prepared by suspension polymerization, and were used as a new support to immobilize Trametes versicolor laccase. The maximum loading capacity to immobilize enzyme reached as high as 44.78 mg protein/g support. The stability and reusability of laccase were greatly improved after immobilization on the microspheres. While the immobilized laccase was used as catalyst to remove p-benzenediol from wastewater, the removal efficiency reached 88.5%.

Hierarchical MnO2 nanostructures: synthesis and their application in water treatment.

Hierarchical MnO2 nanostructures were prepared through the reaction between KMnO4 and oleic acid at room temperature in the surfactant-free microemulsion system. The obtained samples were characterized by powder X-ray diffraction, N2 adsorption, scanning electron microscopy, and transmission electron microscopy. The results indicated that the flowerlike nanospheres were three-dimensional (3D) porous microstructures consisting of nanoplates. The surface area of the sample was 171.5 m(2)/g and the distribution of pore diameter lay within the range of 5-15 nm. The prepared hierarchically structured MnO2 showed excellent adsorption capacity and rapid adsorption rate for methylene blue ions in water. The maximum adsorption capacity of methylene blue was as high as 273.9 mg/g and 97.5% of the dye was removed within initial 5 min of contact time. Compared with other adsorbents, the synthesized hierarchical MnO2 nanostructures displayed a faster adsorption rate and higher adsorption capacity, which implied potential application for removing dye pollutants from waste water.