Upgrading pyrolytic carbon-blacks (CBp) from end-of-life tires: Characteristics and modification methodologies

• Modification methodologies of upgrading CBp from ELTs were reviewed. • Surface microstructures and physiochemical properties of CBp were analyzed. • Future perspectives of ELTs pyrolysis industries were suggested. Over 1 billion end-of-life tires (ELTs) are generating annually, and 4 billion ELTs are currently abandoned in landfills and stockpiles worldwide, according to the statistics, leading to the environmental and health risks. To circumvent these issues, pyrolysis, as an attractive thermochemical process, has been addressed to tackle the ELTs’ problem to reduce the risks as well as increase the material recycling. However, due to the lack of systematic characteristic analysis and modification methods, poor quality of CBp limits the improvement of ELTs pyrolysis in industry applications, which plays a crucial role in the economic feasibility of pyrolysis process. In this review, we have summarized the state-of-the-art characteristics and modification methodologies of the upgrading of CBp, to in-depth understand the surface microstructures and physiochemical properties of CBp for the foundation for modification afterwards. By virtue of the proper selection of modification methods and modifying agents, the new generation of multifunctional carbon materials with desired properties can be instead of the traditional materials of CB, promising broader and various application fields.     

Modeling and simulation study of the stoichiometric niche space and niche overlap based on the copula method

Environmental and Ecological Statistics - To qualify niche space and niche overlap, the current methods are based on a strict assumption of the normal distribution and restrict dependence to the...     

Spatial health risk assessment and hierarchical risk management for mercury in soils from a typical contaminated site,China

Due to rapid urbanization and the implementation of ecological civilization construction in China, many industrial factories have been closed or relocated. Therefore, numbers of contaminated sites were generated with contaminated soils which may pose a risk to receptors living nearby. This study presented a spatial health risk assessment and hierarchical risk management policy making for mercury (Hg) in soils from a typical contaminated site in the Hunan Province, central China. Compared with the second class value (0.3 mg/kg) of the Chinese Environmental Quality Standard for Soils, the mean concentrations of Hg in the three soil depths exceeded the second class value. The non-carcinogenic risk of Hg probably posed adverse health effects in 41, 30 and 36 % of the surface soil, the moderate soil and subsoil, respectively, under a sensitive land scenario. The non-carcinogenic risk temporarily posed no adverse health effects in most areas under an insensitive land scenario except for the area around sampling site S29. Spatially, the central, southwest and northeast parts of the contaminated land under a sensitive land scenario should be regarded as the priority regions. For non-carcinogenic effects, the exposure pathways that resulted in the higher levels of exposure risk were ingestion and inhalation of vapors, followed by dermal contact and inhalation of particles. A risk-based integrated risk management policy including the hierarchical risk control values for different soil depths and the calculated remediation earthwork was proposed with consideration of the cost-benefit effect for the related decision-makers.     

Biodegradation of 3,5-dimethyl-2,4-dichlorophenol in saline wastewater by newly isolated Penicillium sp. yz11-22N2

In this study,the performance of 3,5-dimethyl-2,4-dichlorophenol(DCMX) degradation by a screened strain was investigated.18 S r DNA and the neighbor-joining method were used for identification of the isolated strain.The results of phylogenetic analysis and scanning electron micrographs showed that the most probable identity of the screened strain should be Penicillium sp.Growth characteristics of Penicillium sp.and degradation processes of DCMX were examined.Fourier transform infrared spectroscopy of the inoculated DCMX solution was recorded,which supported the capacity of DCMX degradation by the screened Penicillium sp.Under different salinity conditions,the highest growth rate and removal efficiency for DCMX were obtained at p H 6.0.The removal efficiency decreased from 100%to 66% when the DCMX concentration increased from 5 to 60 mg/L,respectively.Using a Box–Behnken design,the maximum DCMX removal efficiency was determined to be 98.4%.With acclimation to salinity,higher removal efficiency could be achieved.The results demonstrate that the screened Penicillium sp.has the capability for degradation of DCMX.     

Influences of anion concentration and valence on dispersion and aggregation of titanium dioxide nanoparticles in aqueous solutions

Dispersion and aggregation of nanoparticles in aqueous solutions are important factors for safe application of nanoparticles. In this study, dispersion and aggregation of nano-TiO₂ in aqueous solutions containing various anions were investigated. The influences of anion concentration and valence on the aggregation size, zeta potential and aggregation kinetics were individually investigated. Results showed that the zeta potential decreased from 19.8 to − 41.4 mV when PO₄^3 − concentration was increased from 0 to 50 mg/L, while the corresponding average size of nano-TiO₂ particles decreased from 613.2 to 540.3 nm. Both SO₄^2 − and NO₃⁻ enhanced aggregation of nano-TiO₂ in solution. As SO₄^2 − concentration was increased from 0 to 500 mg/L, the zeta potential decreased from 19.8 to 1.4 mV, and aggregate sizes increased from 613.2 to 961.3 nm. The trend for NO₃⁻ fluctuation was similar to that for SO₄^2 − although the range of variation for NO₃⁻ was relatively narrow. SO₄^2 − and NO₃⁻ accelerated the aggregation rapidly, while PO₄^3 − did so slowly. These findings facilitate the understanding of aggregation and dispersion mechanisms of nano-TiO₂ in aqueous solutions in the presence of anions of interest.     

利用矿山采空区处置城市垃圾的研究

提出了利用矿山井下采空区处置城市垃圾的设想,并对所涉及的内容、工艺、研究方案进行了研讨和技术经济分析,为城市垃圾的处理将提供一条新的途径。     

城市污水量短时预测的混沌神经网络模型

通过分析进水水量时间序列的非线性动力学性质,认为该时间序列具有混沌特性.在此基础上,通过相空间重构的方法建立了用于城市污水水量短时预测的混沌神经网络模型;并利用此模型对污水厂的进水水量进行短时预测,取得了较为满意的预测效果.     

旅游度假区环境影响的经济分析

以岳阳南湖旅游度假区为产例，探讨了旅游度假区环境影响的费用效益分析方法，分析时以旅游度假区的环境保护设施建设费及其运行费作为环保费用，以采取环保措施后可避免的旅游业，渔业，房地产业等的污染损失作为环保效益，根据社会折现率折算成现值进行比较。     

电导率温度校正计算方法的改进

通过实验，用分段函数较精确的表示出温度校正系数与温度的关系，对现行电导率温度校正公式进行了改进，可以简化测量过程，提高计算精度。