Diethylenetriaminepentaacetic Acid (DPTA)-modified Magnetic Cellulose Nanocrystals can Efficiently Remove Pb(II) from Aqueous Solution

Journal of Polymers and the Environment - Surface modification of cellulose nanocrystals (CNC) is essential for improving their reactivity and adsorption capacity. Oxidation, as a conventional...     

Reinforcing and Toughening Modification of PPC/PBS Blends Compatibilized with Epoxy Terminated Hyperbranched Polymers

Journal of Polymers and the Environment - Polypropylene carbonate (PPC)/polybutylene succinate (PBS) blends were prepared by melt-blending with terminal epoxy-based hyperbranched polymers (EHBP) as...     

次区域城市群协同发展时空演变及动态模拟研究——以宜荆荆恩城市群为例

建立"经济水平—交流服务—产业发展—生态文明—公共服务—科技创新"框架,以宜荆荆恩城市群为例,并与相似区域城市群对比,综合运用耦合协调度、BP神经网络模型、ArcGIS空间分析工具研究次区域城市群协同发展时空演变规律及发展趋势。结果表明:(1)宜荆荆恩城市群综合发展能力指标总体协调发展不均衡。(2)与苏锡常都市圈相比,宜荆荆恩城市群的综合协同发展水平较低,且处于波动状态。(3)在动态模拟方面,宜荆荆恩城市群2020—2025年协同水平差距将持续增大,其协同发展水平在南北方向呈倒"U"型,东西方向呈"两边低,中间高"的趋势。     

Evidence for the involvement of Fe(IV) in water treatment by Fe(III)-activated sulfite

Water contamination by emerging organic pollutants is calling for advanced methods of remediation such as iron-activated sulfite-based advanced oxidation. Sulfate radical, SO₄^??, and hydroxyl radical, ^?OH, are the primary reactive intermediates formed in the Fe(III)/sulfite system, yet the possible involvement of Fe(IV) produced from Fe(II) and persulfates is unclear. Here we explored the role of Fe(IV) in the Fe(III)/sulfite system by methyl phenyl sulfoxide (PMSO) probe assay, electron paramagnetic resonance spectra analysis, alcohol scavenging experiment, and kinetic simulation. Results show that PMSO is partially transformed into methyl phenyl sulfone (PMSO₂), thus evidencing Fe(IV) formation. The remaining degradation of PMSO is due to SO₄^?? and ^?OH. The contribution of Fe(IV) versus free radicals is progressively promoted when the Fe(III)-sulfite reaction proceeds, with an upper limit of 80–90%. The contribution of Fe(IV) versus free radicals increases with Fe(III) and sulfite dosages, and decreases with increasing pH. Overall, our findings demonstrate the involvement of Fe(IV) in the Fe-catalyzed sulfite auto-oxidation process.

     

Biopolymer-based membranes from polysaccharides for CO2 separation: a review

Environmental Chemistry Letters - The application of natural biopolymers such as polysaccharides for the fabrication of bio-based membranes has recently attracted attention for CO2...     

Spatiotemporal variations of dissolved organic matter in a typical multi-source watershed in northern China: a fluorescent evidence

Environmental Science and Pollution Research - The amount of dissolved organic matter (DOM) in a multi-source watershed is important for complete management and assessing the river basin’s...     

Preparation and performance characterization of a new dust suppressant with a cross-linked network structure for use in open-pit coal mines

Environmental Science and Pollution Research - In an effort to control dust pollution in open-air environments such as pit coal mines and coal transportation systems, a new dust suppressant with a...     

Influence of different inoculation densities of black soldier fly larvae (Hermetia illucens) on heavy metal immobilization in swine manure

The disposal of organic waste by the biocomposting of black soldier fly larvae (BSFL) has drawn broad attention. However, the discrepancies in heavy metal immobilization between BSFL biocomposting with different inoculation densities and aerobic composting need to be further researched. In this study, BSFL with inoculation densities of 0.08%, 0.24% and 0.40% was added to swine manure to investigate its influence on heavy metal bioaccumulation and bioavailability. The physicochemical properties, BSFL growth performance and amino acid contents were measured. The results showed that the germination index, total prepupal yield and bioavailable fraction removal rate (%) of Cr and Pb at an inoculation density of 0.40% of BSFL were the highest among all of the BSFL biocomposting groups. Although the bioaccumulation factor and heavy metal (Cd, Cr, Cu and Zn) concentrations of the BSFL body from swine manure with inoculation densities of 0.24% and 0.40% of BSFL were similar, the BSFL inoculation density of 0.40% had the best absorption effect on these heavy metals in terms of total prepupal yield. Therefore, this study provides a basis for exploring the optimal inoculation density of BSFL biocomposting to reduce the harmful effects of heavy metals in swine manure.

     

漳河上游流域沉积物中磷的空间分布特征及其影响因素

漳河上游地区众多的水利工程改变了流域水循环,同时也影响了河流泥沙和生源物质的循环过程。为揭示人类活动干扰下的沉积物中磷的赋存特征,采用改进后的连续化学萃取法分析了漳河上游沉积物中总磷(TP)和磷形态的空间分布特征及其影响因素。研究结果表明,漳河上游沉积物中的TP含量为405.94~899.98 mg/kg,低于我国其他主要河流,接近我国东部平原湖泊含量水平。漳河上游的TP富集指数(PEI)均值为1.15,表明漳河上游富营养化风险较高。可交换态磷(Ex-P)、铁锰螯合态磷(BD-P)、铁铝氧化态磷(NaOH-P)、钙结合态磷(HCl-P)分别占沉积物中TP含量的1.13%、33.96%、12.99%、35.05%。BD-P和HCl-P是沉积物中主要的磷形态,Ex-P的含量最低,NaOH-P的含量波动最大。漳河上游沉积物中,生物可利用磷(BAP)的含量约占TP含量的38.36%~52.04%,其中,清漳干流的BAP含量明显低于其他河段。清漳源头的水土流失及浊漳河的磷输入对漳河上游BAP含量的贡献较大。统计分析显示,漳河上游表层沉积物中,TP和磷形态的空间分布无显著差异,表明以水利工程建设为代表的强烈人类活动对漳河上游沉积物中磷的空间分布的影响不显著。相关性分析和冗余分析表明,沉积物中的NaOH-P含量与沉积物中黏土和粉土的占比有较高的相关性,BD-P和NaOH-P是控制沉积物中BAP构成的重要因素,Fe含量是沉积物中TP含量的主控因子。     

预浓缩-GC/MS测定空气中的27种ODS和HFCs

优化预浓缩仪二级冷阱温度和柱温箱初始温度,建立了预浓缩-气相色谱 /质谱联用(GC/MS)技术测定空气中27种消耗臭氧层物(ODS)和氢氟烃(HFCs)的分析方法。结果表明,27种ODS和HFCs峰形良好,分离度较好,校准曲线相对响应因子标准偏差为1.7%~15.9%,方法检出限为0.016~0.172 μg/m³。空白加标样品连续测定6次的相对标准偏差为0.9%~13.4%,回收率为70.4%~116%。基体加标样品连续测定6次的相对标准偏差为1.0%~7.8%,回收率为94.3%~108%。实验楼周边的环境空气以及实验室内部工作环境空气均检出不同浓度的ODS和HFCs,该方法适用于空气中ODS和HFCs的测定。