Research progress and hot spots of hydrothermal liquefaction for bio-oil production based on bibliometric analysis

Environmental Science and Pollution Research - Hydrothermal liquefaction (HTL) of biomass used HTL reaction under high temperature and pressure to produce bio-oil. This technology is considered as...     

TiO2 photocatalytic degradation of PCBs in soil-water systems containing fluoro surfactant

Titanium dioxide-mediated photodegradation of Polychlorinated biphenyls (PCBs) in soil/aqueous systems with added fluorinated surfactant was investigated. PCBs can bind tightly to organic matter in the soil, especially in aged, contaminated soil. Experiments showed an effective PCB photocatalytic degradation in mixed systems of soil/clay with anionic fluorinated surfactant FC-143 and TiO2. The FC-143 surfactant is stable in this photochemical process. PCB degradation rates in samples followed the order: spiked clay > spiked soil > Hudson River bank soil. The results suggest that anionic fluorinated surfactant may form semimicelles and/or admicelles on the surface of positively charged TiO2. The hydrophobic surface of TiO2 can provide a nonpolar phase that acts as a partioning medium for hydrophobic PCBs. Therefore, PCBs in soil can be released to the semimicelle and/or admicelle on the TiO2 surface and are effectively photodegraded in a dispersion containing anionic fluorinated surfactant. The combination of surfactant extraction and photooxidation forms the basis for a novel two-stage process for the removal and destruction of PCBs from soil.     

复合沸石动态膜系统的脱氨效能及其对沸石的同步回收

为同步实现吸附脱氨和微尺寸沸石回收,将沸石与动态膜技术耦合联用,构建了一种复合沸石-动态膜系统,并考察其脱氨和沸石回收效果。在初始氨氮质量浓度为10 mg·L⁻¹条件下,投加10 g·L⁻¹沸石可有效实现氨氮的去除,去除率为67%。吸附动力学和等温模型分析结果表明,该过程符合准二级动力学模型,Langmuir吸附等温模型拟合得到的最大氨氮吸附量为4.12 mg·g ⁻¹。按照1:1的质量比投加沸石与硅藻土,在投加量均为1 g·L⁻¹,流量为40 mL·min⁻¹,支撑膜孔径38 μm下可快速形成动态膜,出水浊度稳定在1 NTU以下,氨氮去除率可达到56%,在脱氨的同时能够实现沸石的有效回收。该研究结果可为复合沸石动态膜系统同步吸附脱氨和吸附材料回收提供参考。     

Risk assessment of particulate matter by considering time-activity-pattern and major microenvironments for preschool children living in Seoul,South Korea

Environmental Science and Pollution Research - Preschool children aged 3–6 years are vulnerable to exposed to particulate matter (“PM10” and “PM2.5”). It is required...     

Polychlorinated dibenzo-p-dioxins and dibenzofurans from food salt samples processed by heat treatment in Korea

Eight samples of processed food salt collected from five plants in Korea were analyzed for 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) using liquid-liquid extraction, clean-up procedures, and high resolution gas chromatography-high resolution mass spectrometry. The study included the analyses of two kinds of salt product sample: bamboo-salt and parched salt. The levels of toxic PCDD/Fs found in the salt product samples were extremely low: the results revealed TEQ levels ranging between the sub pg TEQ/g and sub fg TEQ/g. The differences in the TEQ values of toxic PCDD/F were observed between the salt product samples, which were treated with different frequency of baking using four different fuels (firewood, pine wood, pine resin, and indirect heating by gas) at temperatures from 300 to 2000 degrees C. In bamboo-salt samples, the concentrations and TEQ values of toxic PCDD/Fs ranged between 0.57-66 pg/g and 5.7x10(-5)-0.64 pg TEQ/g, respectively. PCDD/Fs levels in bamboo-salts baked by firewood were found to be higher than those baked by pinewood or pine resin. In parched salt samples, the concentrations and TEQ values of toxic PCDD/Fs ranged between 0.97-3.7 pg/g and 0.0097-0.017 pg TEQ/g, respectively. The data was discussed regarding the concentration and the distribution pattern of congeners.     

Sorption of polar and nonpolar organic contaminants by oil-contaminated soil

Sorption of nonpolar (phenanthrene and butylate) and polar (atrazine and diuron) organic chemicals to oil-contaminated soil was examined to investigate oil effects on sorption of organic chemicals and to derive oil–water distribution coefficients (K_oil). The resulting oil-contaminated soil–water distribution coefficients (K_d) for phenanthrene demonstrated sorption-enhancing effects at both lower and higher oil concentrations (C_oil) but sorption-reducing (competitive) effects at intermediate C_oil (approximately 1 g kg⁻¹). Rationalization of the different dominant effects was attempted in terms of the relative aliphatic carbon content which determines the accessibility of the aromatic cores to phenanthrene. Little or no competitive effect occurred for butylate because its sorption was dominated by partitioning. For atrazine and diuron, the changes in K_d at C_oil above approximately 1 g kg⁻¹ were negligible, indicating that the presently investigated oil has little or no effect on the two tested compounds even though the polarity of the oil is much less than soil organic matter (SOM). Therefore, specific interactions with the active groups (aromatic and polar domains) are dominantly responsible for the sorption of polar sorbates, and thus their sorption is controlled by available sorption sites. This study showed that the oil has the potential to be a dominant sorptive phase for nonpolar pollutants when compared to SOM, but hardly so for polar compounds. The results may aid in a better understanding of the role of the aliphatic and aromatic domains in sorption of nonpolar and polar organic pollutants.     

适用于我国农村地区的低温空气源热泵采暖技术

基于我国农村特点提出采用清洁能源利用技术——低温空气源热泵采暖方式替代农村传统的散煤燃烧取暖方式。低温空气源热泵采用较为成熟可靠的补气增焓技术。研究表明:在蒸发温度为-30 ℃、冷凝温度为45 ℃、补气比为0.6的模拟工况下运行,低温空气源热泵理论制热性能系数(COP)大于2.25,系统能效比(EER)高于1.90。在实际应用过程中,低温空气源热泵机组可解决不同场合下需依靠不同介质(热风或热水)采暖的问题,预计全面推广后,我国农村地区每年可减少二氧化碳、二氧化硫、氮氧化物和粉尘排放分别约3.86亿、0.115亿、0.057亿和1.05亿t,其可作为淘汰农村传统采暖方式的优先选择。     

东江流域水污染控制与水生态系统恢复技术与综合示范

归纳了水专项东江项目2008—2013年的主要研究成果:针对保护优质水源的国家需求,选择典型的东江流域开展前瞻性的水污染控制技术研发并进行工程示范,创建了由常规水质指标实时在线化,痕量污染物控制指标识别筛选全流域优化,生物毒性指标甄别多属性全程化等成套技术构成的水源流域水质风险识别技术体系;由各类工艺废水脱毒减害,同质污水区域集中强化处理,排水持续净化等成套技术构成的水环境风险控制工程技术体系;由水生物链各物种生长状况评级,生境恢复和物种受损关键环节恢复等成套技术构成的生态健康维护技术体系。集成以上3个技术体系形成成套的流域水环境风险控制技术体系集。基于上述技术创新提出了“控制风险、维护生态、保水甘甜、发展持续”的水源流域管理创新总体策略。研发的技术体系与策略在东江流域的示范与应用,实现了东江主干流水质常年优于Ⅱ类的污染控制目标。     

炼油厂恶臭污染物的防治

论述了炼厂恶臭气体的防治方法，主要从密闭的生产装置、酸性水储罐及污水处理系统几个方面进行了分析并提出了目前为解决恶臭污染采取的方法。