Enhanced removal of dimethyl phthalate using heterogeneous UVC/VUV-Fenton amendment with Fe3O4@CM-ß-CD/rGO catalyst: Efficiency, degradation mechanism and toxicity.

Dimethyl phthalate (DMP) is widely used as plasticizer, and this kind of plastic industry wastewater is refractory due to the complex chemical structure and endocrine disrupting property. In order to effectively degrade and mineralize DMP contaminated wastewater, a heterogeneous UVC/VUV-Fenton catalyst system was designed with the amendment of targeted design catalyst Fe3O4@CM-ß-CD/rGO with core-shell like structure covered with loose convex folded lamellar. The optimum removal and mineralization efficiency of DMP were 98.6 % and 62.8 % in 30 min with 150 mg L-1 Fe3O4@CM-ß-CD/rGO and 8 mmol L-1 H2O2. This efficient and fast removal were attributed to a variety of photocatalytic oxidative active species •OH, •O2- and h+ with 59.6%, 29.1% and 9.9% contribution ratio, which mainly took effect on benzene ring open and side-chain fracture by oxidative, hydrolysis and hydrogen substitution determined by the rupture energy requirement from chemical bond in DMP. The target function of CM-ß-CD in catalyst controlled the photo-electron generation rate and shorten mass transfer distance by the cladding lamellar, moreover, rGO accelerated the redox between Fe (II) and Fe (III) and electron transfer. The catalytic recovery and removal to DMP kept above 90 % after five recycles. This study provided an excellent performance catalyst and an effective photo-Fenton approach and for the treatment of endocrine disrupting wastewater.

Design and preparation of carbon material catalyst modified with metal framework and sulfonate for biochar generation from low-temperature directional pyrolysis of kitchen waste: Mechanism and performance.

In order to reduce the pyrolysis temperature during the process of directional conversion from kitchen waste (KW) into aromatic biochar, a kind of catalyst was prepared with carbon material coated with tri-metallic oxide (Fe2O3, MgO and Al2O3) combining with sulfonic acid groups (CMO@SA) according to KW compositions. The aromaticity of KW pyrolysis biochar (KWB) increased when the temperature ranged from 170 to 210 °C. The catalytic pyrolysis temperature of KW reduced from 500 to 190 °C for biochar generation with similar aromaticity due to amendment of CMO@SA. The maximum adsorption capacity of catalytic pyrolysis KWB was 160.23 mg/g for dyeing wastewater, which was equivalent to biochar generated at 500 °C. The decrease of pyrolysis temperature was attributed to the reduction of bonds fracture activation-energy among CH, CC and CO under the catalytic function. The catalytic activity and recovery of CMO@SA kept at 92 % and 90 % after five recycle.