Screening of textile finishing agents available on the Chinese market: An important source of per- and polyfluoroalkyl substances to the environment

Kendrick mass defect was used for PFASs screening in textile finishing agents (TFAs). Total oxidizable precursor assay provides insight into unknown precursors. Perfluorooctane sulfonate was found as impurity in short ECF technology based TFAs. Perfluorooctanoate was also detected in C6 telomerization based TFAs. Long chain precursors were also observed in both types of TFAs. Organofluorinated surfactants are widely employed in textile finishing agents (TFAs) to achieve oil, water, and stain repellency. This has been regarded as an important emission source of per-and polyfluoroalkyl substances (PFASs) to the environment. China is the biggest manufacturer of clothes, and thus TFA production is also a relevant industrial activity. Nevertheless, to date, no survey has been conducted on PFAS contents in commercially available TFAs. In the present study, TFA products were investigated by the Kendrick mass defect method. The quantification results demonstrated a significant presence of perfluorooctane sulfonate (0.37 mg/L) in TFAs manufactured by electrochemical fluorination technology. The products obtained by short-chain PFAS-based telomerization were dominated by perfluorooctanoic acid (mean concentration: 0.29 mg/L), whose values exceeded the limits stated in the European Chemical Agency guidelines (0.025 mg/L). Moreover, the total oxidizable precursor assay indicated high levels of indirectly quantified precursors with long alkyl chains (C7–C9). Together, these results suggest that there is currently a certain of environmental and health risks in China that originates from the utilization of TFAs, and a better manufacturing processes are required to reduce such risks.     

“二段法”干化工艺在中国城市污泥处置中的应用和实践

目前我国城市污水厂产生的湿污泥数量巨大,但大多未能得到安全处置。污泥干化作为解决城市污泥最终减量化、无害化、稳定化和资源化的重要处理方式,近年来得到广泛推广。与其他污泥干化工艺相比,"二段法"干化工艺在能耗、安全性等方面具有明显优势,越来越受到国内外的青睐。但另一方面,某些地区的污泥出现纤维含量高、易混入硬物、黏性高等问题,又阻碍其生产稳定运行。通过苏州工业园区污泥干化项目的实践,因地制宜,对"二段法"干化工艺在运行中出现的问题采取了针对性改进措施,实现了生产连续稳定运行。     

武汉市与西安市颗粒物PM_(10)、PM_(2.5)的污染水平分析

利用武汉、西安两市2013年PM10与PM2.5的监测数据,统计分析了武汉市和西安市PM10与PM2.5的污染水平,并比较了两城市的污染水平。根据GB 3095—2012《中华人民共和国环境空气质量标准》规定的二级浓度限值,可知武汉市和西安市PM2.5的污染都非常严重,PM10的污染相对较轻。从整体上说,西安市的污染水平要比武汉市严重,其中西安市PM10中PM2.5约占79%。武汉市和西安市的相关部门都应重视PM10和PM2.5的污染问题。     

泰达化工区污水处理厂升级改造工程设计

由于实际进水水质高于原设计水质以及排放标准的提高,对原工艺进行改造,改造后主体工艺流程为气浮-水解酸化-生物流化床-MBR-活性炭吸附。经过3个月的稳定运行,出水基本达到1级B标准。总结了化工废水处理升级改造工程的技术特点,为满足1级B排放标准条件下化工废水处理积累了设计经验。     

Changes in speciation and leaching behaviors of heavy metals in dredged sediment solidified/stabilized with various materials

Solidification/stabilization (S/S) of sediments is frequently used to treat contaminants in dredged sediments. In this study, sediment collected from the Pearl River Delta (China) was solidified/stabilized with three different kinds of functional materials: cement, lime and bentonite. Lime primarily acted via induced increases in pH, while cements stabilization occurred through their silicate-based systems and the main function of bentonite was adsorption. The speciation and leaching behaviors of specific heavy metals before and after S/S were analyzed and the results showed that the residual speciation of Cd, Cr, Ni, Pb and Zn increased in all treatments except for Cu, as the exchangeable speciation, carbonate-bound speciation and Fe-Mn-oxide-bound speciation of Cu (all of which could be stabilized) were less than 2 % of the total amount. Pb leaching only decreased when pH increased, while the mobility of Cr and Ni only decreased in response to the silicate-based systems. The leached portion of the Fe-Mn-oxide-bound speciation followed the order Zn?>?Cu?>?Ni/Cd?>?Pb?>?Cr. The leached portion of organic-matter-bound species was less than 4 % for Cd, Cr, Ni and Pb, but 35.1 % and 20.6 % for Cu and Zn, respectively.     

Occurrence of 25 pharmaceuticals in Taihu Lake and their removal from two urban drinking water treatment plants and a constructed wetland

Environmental Science and Pollution Research - Pharmaceuticals in drinking water sources have raised significant concerns due to their persistent input and potential human health risks. The...     

外源Mo降低As(Ⅲ)和As(Ⅴ)对水稻的毒性及As的积累

通过溶液培养试验,研究外源添加Mo对2种价态砷(As(Ⅲ)和As(Ⅴ))胁迫下水稻吸收积累Mo和As的影响。结果表明,这2种价态的As对水稻生长均有抑制作用,As(Ⅲ)比As(Ⅴ)对水稻毒害更明显,添加Mo可缓解As对水稻的毒害。As添加可影响水稻根系和茎叶对Mo的吸收积累,但是不同价态As对Mo积累量的影响不一致。同时,Mo的添加也可以显著地降低水稻根系和茎叶对2个价态As的吸收积累。在100μmol·L~(-1)As(Ⅲ)处理下,添加0.1和0.5 mg·L~(-1)的Mo可导致水稻根系As积累量分别比对照处理降低38.8%和52.8%,茎叶As积累量分别降低5.1%和10.6%;当As(V)浓度为100μmol·L~(-1)时,添加0.1和0.5 mg·L~(-1)的Mo可导致水稻根系As积累量分别比对照处理降低15.4%和62.4%,茎叶As积累量分别降低11.9%和23.7%。Mo的添加还能显著地降低2种价态As在水稻根系和茎叶中的富集系数。因此,通过施用适量的Mo肥可以用来防治农田As污染,降低As对人体健康的危害。     

外源Mo降低As(III)和As(V)对水稻的毒性及As的积累

通过溶液培养试验,研究外源添加Mo对2种价态砷(As(III)和As(V))胁迫下水稻吸收积累Mo和As的影响。结果表明,这2种价态的As对水稻生长均有抑制作用,As(III)比As(V)对水稻毒害更明显,添加Mo可缓解As对水稻的毒害。As添加可影响水稻根系和茎叶对Mo的吸收积累,但是不同价态As对Mo积累量的影响不一致。同时,Mo的添加也可以显著地降低水稻根系和茎叶对2个价态As的吸收积累。在100 μmol?L^-1 As(III)处理下,添加0.1和0.5 mg?L^-1的Mo可导致水稻根系As积累量分别比对照处理降低38.8%和52.8%,茎叶As积累量分别降低5.1%和10.6%;当As(V)浓度为100 μmol?L^-1时,添加0.1和0.5 mg?L^-1的Mo可导致水稻根系As积累量分别比对照处理降低15.4%和62.4%,茎叶As积累量分别降低11.9%和23.7%。Mo的添加还能显著地降低2种价态As在水稻根系和茎叶中的富集系数。因此,通过施用适量的Mo肥可以用来防治农田As污染,降低As对人体健康的危害。     

评价城市基础设施自然灾害连锁效应的结构方法

介绍一种新的结构方法来评价城市基础设施自然灾害及连锁效应,通过对城市基础设施任务有效性变化的结果分析(第一步)和脆弱性分析(第二步)实现了城市基础设施自然灾害从定性到定量的精确评价,为城市基础设施防灾减灾研究提供一种方法指导和解决措施.     

渤南低渗透油田污水生化处理室内模拟研究

渤南油田属典型的低渗透油田,注水水质要求达到A1级,而污水中的分散油和乳化油是污水处理的难点和重点。为给污水站的建设提供合适的污水处理工艺单元和最佳参数,通过室内模拟研究,采用生物接触氧化技术处理油田污水。结果表明,当污水停留时间为8 h时,生化系统可将污水含油量由10～25 mg/L降低到1 mg/L以下,去除率高达96.18%,COD稳定在100 mg/L以内,通过生物之间的竞争作用和高浓度的氧,有效地抑制了硫酸盐还原菌的生长,使腐蚀率控制在0.076 mm/a以下。同时,该试验表明,8 h为生物接触氧化处理工艺的最佳停留时间。