To avoid the disadvantages caused by using silica fume, by using superfine cement (SC) to substitute silica fume, a new kind of ultra high performance concrete (SC-UHPC) was prepared and introduced. The influence of component types and dosages on the mechanical properties of SC-UHPC was investigated. The results show that 40% ground granulated blast furnace slag (GGBFS) or 10% fly ash (FA) & 30% GGBFS replacing SC are the most appropriate proportions to get high strength with satisfied workability and low cost. A suitable amount of defoaming agent (DA) in superplasticizer (SP) effectively reduced the void ratio in the UHPC. To optimize the strength and fluidity, the rational natural sand distribution with lowest clay particles amount can be used. The small sized steel fibers added into the mixture effectively improved the flexural behavior of SC-UHPC. Multiple nonlinear analysis show that, with sufficient calcium silicate hydrate (C-S-H gel) and enough mixture fluidity, the compressive strength of UHPC is closely related to the water to binder ratio and void ratio, and increases linearly with the incremental fiber amount. Microstructure analysis proved that the microstructure of SC-UHPC has ultra high density and homogeneity.

Hexavalent chromium Cr(VI) causes serious damage to human health. In this study, food waste (FW) was used as raw material to prepare the food waste-derived biochar (FWB), which was further modified using Ce and Fe 2+ /Fe 3+ co-precipitation to obtain Ce dopped magnetic waste-derived biochar (Ce/Fe3O4/FWB ) material for the efficient Cr(VI) adsorption. The morphology, structure, and characteristics of Ce/Fe3O4/FWB composite were thoroughly investigated, and its Cr(VI) uptake behavior was explored. Ce/Fe3O4/FWB showed the best Cr(VI) adsorption of 20.4 mg/g at pH 2.Additionally, the adsorption suited the pseudo-second-order kinetic equation and the Langmuir equation, and the intra-particle diffusion the main step limited the Cr(VI) adsorption by Ce/Fe3O4/FWB. The thermodynamic investigation discovered that the adsorption owned a spontaneous and endothermic nature. With increasing concentrations of Cl -, SO4 2and PO4 3-, the Cr(VI) uptake was weakened in the sequence of Cl -＜SO4 2-＜PO4 3-.Adsorbent preparation for Cr(VI) removal utilizing FW as a raw material is a sustainable and environmentally beneficial technology for FW reclamation and Cr(VI)-bearing wastewater treatment.

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The main objective of this study was to investigate the efficacy of using the constructed wetland for purification of secondary effluent from a wastewater treatment plant (WWTP) in the eastern district of Anyang, Henan province, China. A Subsurface Flow Constructed Wetland (SSFCW) system was designed and constructed, consisting of 302 SSFCW units (L×W×H = 30×20×1.4 m for each unit) with a treatment capacity of 10 5 m 3 /d. Each unit of the system was planted with equal number of Phragmites australis, Typha orientalis Presl, and Zizania latifolia at the density of 16 plants/m 2 . The average values of the Chemical Oxygen Demand (COD Cr ), Biochemical Oxygen Demand (BOD 5 ), Ammonia Nitrogen (NH 3 -N), and Total Phosphorus (TP) of the effluent sampled from 4 outlets of the system chosen at random for 17 months consistently met the Class III of Environmental quality standard for surface water in China, even during the cold season. According to the economic analysis, the system may generate an annual profit of around ¥ 1.4 million yuan. The SSFCW system is an cost-effective and profitable technique for the further polish of the secondary effluent from the wastewater treatment plant.

Hexavalent chromium Cr(VI) causes serious damage to human health. In this study, food waste (FW) was used as raw material to prepare the food waste-derived biochar (FWB), which was further modified using Ce and Fe2+/Fe3+ co-precipitation to obtain Ce dopped magnetic waste-derived biochar (Ce/Fe3O4/FWB ) material for the efficient Cr(VI) adsorption. The morphology, structure, and characteristics of Ce/Fe3O4/FWB composite were thoroughly investigated, and its Cr(VI) uptake behavior was explored. Ce/Fe3O4/FWB showed the best Cr(VI) adsorption of 20.4 mg/g at pH 2.Additionally, the adsorption suited the pseudo-second-order kinetic equation and the Langmuir equation, and the intra-particle diffusion the main step limited the Cr(VI) adsorption by Ce/Fe3O4/FWB. The thermodynamic investigation discovered that the adsorption owned a spontaneous and endothermic nature. With increasing concentrations of Cl-, SO42- and PO43-, the Cr(VI) uptake was weakened in the sequence of Cl- ＜SO42- ＜PO43-. Adsorbent preparation for Cr(VI) removal utilizing FW as a raw material is a sustainable and environmentally beneficial technology for FW reclamation and Cr(VI)-bearing wastewater treatment.