Triton X-100 induced cuboid-like BiVO4 microsphere with high photocatalytic performance

A highly active visible light-induced BiVO₄ photocatalyst was prepared by a simple co-precipitation method using ammonia solution as a pH adjustor and Triton X-100 (TX100) as a structure directing agent. The physical properties of the prepared BiVO₄ photocatalyst were investigated by several techniques such as X-ray diffractometer (XRD), Brunauer–Emmett–Teller (BET) surface area measurement, scanning electron microscopy (SEM), energy dispersive analysis (EDS), Fourier-transformed infrared spectroscopy (FT-IR), photoluminescence (PL), and UV–Vis diffused reflectance spectroscopy (DRS). XRD results revealed the existence of a monoclinic scheelite structure in both the unmodified and the modified samples. The TX100 played a crucial role to control the cuboid-like shape morphology of BiVO₄. The DRS results showed that the as-prepared cuboid BiVO₄ possessed enhanced visible light absorption range compared with that of the unmodified BiVO₄. The photocatalytic activity was evaluated via indigo carmine (IC) degradation under visible light irradiation. The modified BiVO₄ showed higher photocatalytic efficiency than the unmodified BiVO₄ and the commercial P25-TiO₂ which could be ascribed to the better charge separation efficiency.     

Tl(Ⅰ)与Tl(Ⅲ)在UV - H2O2体系中的价态转化

建立了chelex-100螯合树脂分离技术与石墨炉原子吸收联用测定水体中Tl(Ⅰ)与Tl(Ⅲ)的方法,分别考察了光化学氧化中pH值、H2O2投加量、光照强度对Tl(Ⅰ)的氧化效果。方法的Tl(Ⅰ)与Tl(Ⅲ)检出量均为0.5μg/L。两者共存时各自加标回收率大于95%。结果表明,在偏酸性环境(pH=3.0),投加适量30%H2O2,光照强度大有利于Tl(Ⅰ)的氧化。当pH=2.91,投加30%H2O2为5 mL,UV照射10min后,Tl(Ⅰ)的转化率达90%。研究表明,光化学氧化可有效转化水体中不易被物理化学法去除的Tl(Ⅰ)和容易被物理吸附、化学沉淀方法去除的Tl(Ⅲ)。     

LCA of local strategies for energy recovery from waste in England, applied to a large municipal flow

An intense waste management (WM) planning activity is currently undergoing in England to build the infrastructure necessary to treat residual wastes, increase recycling levels and the recovery of energy from waste. From the analyses of local WM strategic and planning documents we have identified the emerging of three different energy recovery strategies: established combustion of residual waste; pre-treatment of residual waste and energy recovery from Solid Recovered Fuel in a dedicated plant, usually assumed to be a gasifier; pre-treatment of residual waste and reliance on the market to accept the ‘fuel from waste’ so produced. Each energy recovery strategy will result in a different solution in terms of the technology selected; moreover, on the basis of the favoured solution, the total number, scale and location of thermal treatment plants built in England will dramatically change. To support the evaluation and comparison of these three WM strategy in terms of global environmental impacts, energy recovery possibilities and performance with respect to changing ‘fuel from waste’ market conditions, the LCA comparison of eight alternative WM scenarios for a real case study dealing with a large flow of municipal wastes was performed with the modelling tool WRATE. The large flow of waste modelled allowed to formulate and assess realistic alternative WM scenarios and to design infrastructural systems which are likely to correspond to those submitted for approval to the local authorities. The results show that all alternative scenarios contribute to saving abiotic resources and reducing global warming potential. Particularly relevant to the current English debate, the performance of a scenario was shown to depend not from the thermal treatment technology but from a combination of parameters, among which most relevant are the efficiency of energy recovery processes (both electricity and heat) and the calorific value of residual waste and pre-treated material. The contribution and relative importance of recycling and treatment/recovery processes change with the impact category. The lack of reprocessing plants in the area of the case study has shown the relevance of transport distances for recyclate material in reducing the efficiency of a WM system. Highly relevant to the current English WM infrastructural debate, these results for the first time highlight the risk of a significant reduction in the energy that could be recovered by local WM strategies relying only on the market to dispose of the ‘fuel from waste’ in a non dedicated plant in the case that the SRF had to be sent to landfill for lack of treatment capacity.     

DDT uptake by arbuscular mycorrhizal alfalfa and depletion in soil as influenced by soil application of a non-ionic surfactant

A greenhouse pot experiment was conducted to investigate the colonization of alfalfa roots by the arbuscular mycorrhizal (AM) fungus Glomus etunicatum and application of the non-ionic surfactant Triton X-100 on DDT uptake by alfalfa and depletion in soil. Mycorrhizal colonization led to an increase in the accumulation of DDT in roots but a decrease in shoots. The combination of AM inoculation and Triton X-100 application enhanced DDT uptake by both the roots and shoots. Application of Triton X-100 gave much lower residual concentrations of DDT in the bulk soil than in the rhizosphere soil or in the bulk soil without Triton X-100. AM colonization significantly increased bacterial and fungal counts and dehydrogenase activity in the rhizosphere soil. The combined AM inoculation of plants and soil application of surfactant may have potential as a biotechnological approach for the decontamination of soil polluted with DDT.     

A(sⅢ)和A(sⅤ)对小球藻(Chlorella sp).的生长影响研究

砷是广泛存在于自然界中最常见的毒性污染物,包括土壤,沉积物,水体,大气层,甚至生物体,毒性极强。环境中砷的污染严重威胁人类的健康,已被视为一个全球性的公共卫生问题。为了研究砷对小球藻的生长影响,文章通过实验室培养方式,选取了6个不同浓度的As(Ⅲ()0.5、1.0、2.0、5.0、10.0、20.0 mg/L)和As(Ⅴ()1.0、5.0、10.0、20.0、50.0、100.0 mg/L)的培养处理,以在680 nm下小球藻的吸光度(OD680)作为衡量因子,对小球藻Chlorella sp(.100 ai)在不同浓度砷离子的培养液中的细胞密度进行了试验,整个实验共进行了7 d。结果表明,As(Ⅲ)和As(Ⅴ)浓度分别在10.0 mg/L和20.0 mg/L以上时抑制100 ai细胞生长,导致其密度下降。用概率统计方法计算得到A(sⅢ)对100 ai的96 h半数有效抑制浓度EC50值为25.79 mg/L。参照藻类生长抑制评价标准,A(sⅢ)对100 ai的毒性比A(sⅤ)大。     

Lix54-100从印刷电路板蚀刻废液中回收铜

本文对Lix5 4 10 0萃取剂萃取铜氨料液中铜的性能做了研究 ,发现其具有动力学速率快、饱和容量高、分离效果好、反萃容易及不萃氨等特点。并把其应用于印刷电路板蚀刻废液中铜的回收 ,在铜初始浓度为 15 6.96g/L ,相比为 2∶1条件下 ,用 80 %Lix5 4 10 0 -煤油经过三级错流萃取 ,铜的浓度可下降到 2 6.88g/L。三级总萃取率达 82 .87%。由此设计推荐了无废排放工艺流程 ,实现了经济效益和环境效益的统一     

UNIT HYDROGRAPHS FOR DEVELOPING DESIGN FLOOD HYDROGRAPHS1

ABSTRACT: In Illinois, a procedure has been developed to derive unit hydrographs for generating 100-year and probable maximum flood hydrographs, on the basis of 11 parameters that define the hydrograph shape very well. Regional regressions of these parameters with basin factors show very high correlation. Thus satisfactory values of parameters can be determined for ungaged areas or those with a few years' record. The nonlinearity in unit hydrographs derived from usual floods is largely attributed to mixing within-channel and overbank-flow flood events. To minimize the effects of nonlinearity and to derive unit hydrographa suitable for calculating spillway design floods, use of the proposed method of developing such hydrographs is recommended.     

Sorption of Triton X-100 on soil organic matter fractions：Kinetics and isotherms

Kinetics and isotherms of Triton X-100 sorption on soil,base-extracted soil(BE),humic acid (HA) and humin (HM) were investigated respectively to get better understanding on characteristics of the surfactant sorptiun onto different soil organic matters(SOMs).It was demonstrated that the kinetics results could be satisfactorily described by the pseudo-second order model.The half of the time to reach equilibrium(t1/2) for different sorbents followed the sequence of soil>HA>BE>HM.Furthermore,the calculated equilibrium sorption capacity(Ceq) was found in the sequence of HA>BE>HM>soil,which agreed well with the experimental results.The isotherms of Triton X-100 sorption on soil and HA could be well described by the S-type isotherm,but BE and HM by the L-type.The isotherms of all the four sorbents were found reasonably fitted to the Langmuir equation.The Kd value,defined as the ratio of Triton X-100 in sorbent and in the equilibrium solution for given concentrations,generally followed the order of HM>HA>soil>BE.Separated HM and HA showed high affinity for Triton X-100,but the HA and HM in soil and BE were tightly bounded by the minerals.Thus,the HA on the soil surface might dominate the sorption,whereas the bounded HM would play a key role upon the surfactants being penetrated inside the soil.     

Equilibrium,kinetics and thermodynamics studies on adsorptive removal of cobalt ions from wastewater using MIL-100(Fe)

This study describes experiments in which MIL-100(Fe) was used to remove Co²⁺ ions from the waste water. The synthesised adsorbent was characterised by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction, Brunauer–Emmett–Teller (BET) and scanning electron microscope. Statistical analysis was used to investigate the effects of different parameters. From the obtained results, the removal efficiency was enhanced with increasing contact time and pH but decreased with increasing cobalt initial concentration. The maximum removal efficiency of Co⁺² was 93.4% under optimum conditions. The equilibrium adsorption data were best fitted to linearly transformed Freundlich isotherm. Adsorption kinetic data followed the pseudo second-order kinetic model. The maximum adsorption capacity of Co⁺² on to the MIL-100(Fe) was found to be 119 mg g^?1. The results showed that ?G of adsorption was negative, while ?H was positive which showed that the adsorption process was spontaneous and endothermic. The positive value of ?S showed that disordering and randomness increased at the solid–solution interface of cobalt ions with MIL-100(Fe) particles.