Recent advances in electrochemical decontamination of perfluorinated compounds from water: a review

● Recent advances in the electrochemical decontamination of PFAS are reviewed. ● Underlying mechanisms and impacting factors of these processes are discussed. ● Several novel couped systems and electrode materials are emphasized. ● Major knowledge gaps and research prospects on PFAS removal are identified. Per- and polyfluoroalkyl substances (PFAS) pose serious human health and environmental risks due to their persistence and toxicity. Among the available PFAS remediation options, the electrochemical approach is promising with better control. In this review, recent advances in the decontamination of PFAS from water using several state-of-the-art electrochemical strategies, including electro-oxidation, electro-adsorption, and electro-coagulation, were systematically reviewed. We aimed to elucidate their design principles, underlying working mechanisms, and the effects of operation factors (e.g., solution pH, applied voltage, and reactor configuration). The recent developments of innovative electrochemical systems and novel electrode materials were highlighted. In addition, the development of coupled processes that could overcome the shortcomings of low efficiency and high energy consumption of conventional electrochemical systems was also emphasized. This review identified several major knowledge gaps and challenges in the scalability and adaptability of efficient electrochemical systems for PFAS remediation. Materials science and system design developments are forging a path toward sustainable treatment of PFAS-contaminated water through electrochemical technologies.     

A new comprehensive ecological risk index for risk assessment on Luanhe River,China

With the enhancement of human activities which influence the physical and chemical integrity of ecosystem, it was bound to increase ecological risk to the ecosystem, and the risk assessment of small scale, single pollutant, or only on water quality have been not satisfied the demand of sustainable development of basin water environment. Based on the response relationship between environmental flow requirements guarantee ratio (GEF) and river ecological risk index (ERI), the Sediment Quality Guideline Quotient index (SQG-Q), and the Biotic Index (BI), we construct a new comprehensive ecological risk index (CERI) to evaluate the ecological risk of Luanhe River, China. According to the response relationship between GEF and ERI, upper and lower reaches of Luanhe River (Goutaizi to Hanjiaying) were at moderate risk level (0.41 < ERI < 0.56) in dry season, and all sites were at low risk level (ERI < 0.40) in wet season; considering the contribution of heavy metals contamination in the SQG-Q, the Luanhe River was the most influenced by higher levels of heavy metals in dry season and wet season; when this index was applied to the PAHs levels, only 30 and 20% of the sampling sites appeared to be moderately impacted (0.1 < SQG-Q PAHs < 0.5) by the PAHs in dry season and wet season, respectively. The results of BI showed that half of the sites appeared to be at moderately polluted level (50% of the sites, 0.25 < BI < 0.32) and heavily polluted level (Zhangbaiwan, BI = 0.36) in dry season, and 40% of the sites appeared to be at moderately polluted level (0.26 < BI < 0.29) in wet season. The CERI showed that 70 and 30% of the sites were at moderate risk level in dry season (0.25 < CERI < 0.36) and wet season (0.26 < CERI < 0.29), respectively. The results could give insight into risk assessment of water environment and decision-making for water source security.

     

Hydrogel use in burn therapy,thermal management,wastewater treatment and fire fighting: a review

Environmental Chemistry Letters - Hydrogels are 3-dimensional polymeric networks with unique properties of high flexibility and high water content, and are thus advanced materials for applications...     

特种膜分离在废乳化液处理上的应用

目前国内乳化液处理普遍采用化学加药破乳,再后续生化处理的工艺,该方法投加大量化学药剂,产生二次固体危废,综合处置成本高。采用荷兰B&C特种超滤膜技术对乳化液浓缩破乳回收基础油,超滤产水后续生化处理的新工艺路线具有很好的工艺先进性。通过工艺运行数据显示,含油率1%~3%的乳化液,经过特种超滤浓缩破乳后浓缩液含油率可达15%~20%,超滤产水含油率小于50mg/L,COD为15000~20000mg/L,后续经厌氧和A/O生化+Fenton氧化后出水小于500mg/L,达到处理标准。     

A triangular fuzzy TOPSIS-based approach for the application of water technologies in different emergency water supply scenarios

Environmental Science and Pollution Research - Because of the increasing frequency and intensity of unexpected natural disasters, providing safe drinking water for the affected population following...     

基于TOPSIS的城市自然灾害社会脆弱性评价研究——以上海市为例

城市是人口稠密、经济发达、社会财富高度集中的地区,同时也是自然灾害社会脆弱性较高的地区,评估城市自然灾害社会脆弱性对于提高城市自然灾害的抵抗能力、减少自然灾害造成的人员伤亡和经济损失具有重要意义。以上海市18个区县的人口和社会经济数据为基础构建了45个自然灾害社会脆弱性指标,并用主成分分析法选择了16个独立性强的重要指标作为自然灾害社会脆弱性的评价指标;采用TOPSIS方法对上海市18个区县的自然灾害社会脆弱性进行了评价,揭示了上海市自然灾害社会脆弱性的区域特征,为城市自然灾害风险管理和区域综合防灾减灾提供科学依据。     

长江流域湿地现状与变化遥感研究

湿地与湿地环境问题早已引起国际与国家层面的高度关注。基于多时相卫星遥感数据（MSS、TM/ETM、CBERS 02等），以ERDAS、ARCGIS、MAPGIS等软件为平台，在长江流域系统开展了1975、2000、2007年等不同时相湿地遥感信息提取、编图及以次级流域为单元的统计分析，全面掌握长江流域主要湿地类型、面积、结构、分布现状以及30余a的湿地变化规律，分析其自然及人类地质营力作用机制，研究其变化态势，为流域内国土资源的合理开发利用提供大区域基础资料。结果表明：长江流域湿地现状总面积为7931 9×104 km2，其中河流、湖泊、沼泽、人工湿地各占4233%、2093%、1853%、1821%；湿地类型发育齐全，空间分布广，但次级流域或局域湿地分布严重不匀且[JP2]类型结构不全；从1975~2007年的30余a，湖泊湿地总量消减889×102 km2，沼泽湿地消减591[JP]×102 km2，河流湿地增加350×102 km2，人工湿地增加了6302×103 km2，湿地总量累计增加了5172×103 km2；湿地变化方式主要是面积的增减和类型的转换，变化受制于自然与人类活动地质营力共同作用；湿地变化阶段性特征明显，2000年前为湿地不良变化期，2000年后为良性缓变期，长江流域湿地环境表现为总体趋好、局域问题较多态势     

分光光度法测定氯化氢的实验条件改进

硫氰酸汞分光光度法测定大气中的氯化氢,所使用的硫氰酸汞-乙醇溶液配置时间长,浓度低,曲线线性不好,不适用于环境现场监测。通过对氯化氢测定过程中遇到的问题进行分析,对硫氰酸汞-乙醇溶液的配置方法进行改进,提高该溶液的浓度。实验证明,使用定性滤纸过滤后的0.40%硫氰酸汞-乙醇溶液,曲线线性关系好,标样准确度高,适用于现场监测分析。     

In situ preparation of visible-light-driven carbon quantum dots/NaBiO3 hybrid materials for the photoreduction of Cr(VI)

In this study, different carbon quantum dots (CQDs)/NaBiO₃ hybrid materials were synthesized as photocatalysts to effectively utilize visible light for the photocatalytic degradation of contaminants effectively. These hybrid materials exhibit an enhanced photocatalytic reduction of hexavalent chromium (Cr(VI)) in the aqueous medium. Zero-dimensional nanoparticles of CQDs were embedded within the two-dimensional NaBiO₃ nanosheets by the hydrothermal process. Compared with that of the pure NaBiO₃ nanosheets, the photocatalytic performance of the hybrid catalysts was significantly high and 6 wt.% CQDs/NaBiO₃ catalyst exhibited better photocatalytic performance. We performed the first-principles density functional theory calculations to study the interfacial properties of pure NaBiO₃ nanosheets and hybrid photocatalysts, and confirmed the CQDs played an important role in the CQDs/NaBiO₃ composites. The experimental results indicated that the enhanced reduction of Cr(VI) was probably due to the high loading of CQDs (electron acceptor) on NaBiO_3, which made NaBiO₃ nanomaterials to respond in visible light and significantly improved their electron-hole separation efficiency.     

基于压差的二氧化碳垂直采样分析技术

本研究开发了一套基于直接采样技术的二氧化碳（CO₂）垂直廓线采样分析系统,分析近地面至25km高空CO₂浓度的垂直分布.系统通过压差实现垂直方向连续采样,利用CRDS高精度分析技术对不同高度样品进行定量分析,计算得到采样区域CO₂浓度廓线.于2018年6月13~14日,在内蒙古锡林浩特国家气候观象台利用平流层探空气球平台进行了观测实验.实验室测试显示,CO₂分析准确度优于0.06×10^-6,精度优于0.08×10^-6.外场实验获得区域近地面至25km高空CO₂浓度的高分辨率垂直廓线,显示CO₂在不同高度的分层结构.考虑不同高度样品扩散作用,系统垂直分辨率在10km高度以下优于580m,在10~20km高度优于3.3km.研究表明：分析系统可搭载在合适探空平台上进行CO₂垂直观测,获取浓度廓线,可为传输模式提供数据,并为碳卫星遥感数据提供实测数据校验.