Conversion of waste plastics into value-added carbon materials

Plastic pollution is a major environmental issue worldwide, calling for advanced methods to recycle waste plastics in the context of the circular economy. Here we review methods and strategies to convert waste plastics into value-added carbon materials, with focus on sources, properties, pretreatment of waste plastics, and on preparation of carbon materials. Pretreatment techniques include mechanical crushing, plastic stabilization and electrospinning. Carbon materials such as carbon nanotubes, graphene, carbon nanosheets, carbon spheres and porous carbon are prepared by oxygen-limited carbonization, catalytic carbonization, the template-based method, and pressure carbonization. We emphasize the conversion of polyethene terephthalate, polyethylene, polypropylene, polystyrene, halogenated plastics, polyurethane and mixed plastics.

     

Influence of H2S and NH3 on biogas dry reforming using Ni catalyst: a study on single and synergetic effect

● NH₃ in biogas had a slight inhibitory effect on dry reforming. ● Coexistence of H₂S and NH₃ led to faster decline of biogas conversion. ● Regeneration was effective for catalysts deactivated under synergetic effect. Biogas is a renewable biomass energy source mainly composed of CH₄ and CO₂. Dry reforming is a promising technology for the high-value utilization of biogas. Some impurity gases in biogas can not be completely removed after pretreatment, which may affect the performance of dry reforming. In this study, the influence of typical impurities H₂S and NH₃ on dry reforming was studied using Ni/MgO catalyst. The results showed that low concentration of H₂S in biogas could cause serious deactivation of catalyst. Characterization results including EDS, XPS and TOF-SIMS confirmed the adsorption of sulfur on the catalyst surface, which was the cause of catalyst poisoning. We used air calcination method to regenerate the sulfur-poisoned catalysts and found that the regeneration temperature higher than 500 °C could help catalyst recover the original activity. NH₃ in the concentration range of 50–10000 ppm showed a slight inhibitory effect on biogas dry reforming. The decline rate of biogas conversion efficiency increased with the increase of NH₃ concentration. This was related to the reduction of oxygen activity on catalyst surface caused by NH₃. The synergetic effect of H₂S and NH₃ in biogas was investigated. The results showed that biogas conversion decreased faster under the coexistence of H₂S and NH₃ than under the effect of H₂S alone, so as the surface oxygen activity of catalyst. Air calcination regeneration could also recover the activity of the deactivated catalyst under the synergetic effect of H₂S and NH₃.     

Discovery of emerging organic pollutants in the atmosphere through an omics approach

● We review the framework of discovering emerging pollutants through an omics approach. ● High-resolution MS can digitalize atmospheric samples to full-component data. ● Chemical features and databases can help to translate untargeted data to compounds. ● Biological effect-directed untargeted analyses consider both existence and toxicity. Ambient air pollution, containing numerous known and hitherto unknown compounds, is a major risk factor for public health. The discovery of harmful components is the prerequisite for pollution control; however, this raises a great challenge on recognizing previously unknown species. Here we systematically review the analytical techniques on air pollution in the framework of an omics approach, with a brief introduction on sample preparation and analysis, and in more detail, compounds prioritization and identification. Through high-resolution mass spectrometry (HRMS, typically coupled with chromatography), the complicated environmental matrix can be digitalized into “full-component” data. A key step to discover emerging compounds is the prioritization of compounds from massive data. Chemical fingerprints, suspect lists and biological effects are the most vital untargeted strategies for comprehensively screening critical and hazardous substances. Afterward, compressed data of compounds can be identified at various confidence levels according to exact mass and the derived molecular formula, MS libraries, and authentic standards. Such an omics approach on full-component data provides a paradigm for discovering emerging air pollutants; nonetheless, new technological advancements of instruments and databases are warranted for further tracking the environmental behaviors, hence to evaluate the health risk of key pollutants.     

关于国家环境保护“十三五”规划的战略思考

在对我国当前环境形势以及未来重大环境保护问题识别的基础上,结合国家生态文明建设新要求,提出了"十三五"环境保护规划体系以及规划目标的设想,并从国民经济绿色化、国土空间功能化、保护环境法治化、环境供给市场化、决策监管科学化、治理主体多元化、环境信息公开化等7个方面给出了基本策略建议,可为制定国家"十三五"环境保护规划提供参考。     

十溴二苯乙烷对蚯蚓亚急性毒性及微生物群落结构影响

新型溴系阻燃剂十溴二苯乙烷(DBDPE)生产和使用量日益增大,在环境中的检出率越来越高,其生态风险正受到广泛关注.然而,有关DBDPE对陆地无脊椎生物毒性效应以及微生物群落结构的影响知之甚少.探究了不同剂量(5、10、20、50和100mg·kg-1)DBDPE暴露对赤子爱胜蚓(Eisenia fetida)生长、行为...     

六种表面活性剂对斑马鱼胚胎发育的毒性效应

为评价六种常见农药表面活性剂对水生生物的风险,采用斑马鱼胚胎发育技术,研究其对斑马鱼胚胎的致死效应和致畸效应.结果表明,NP-10、OP-10、农乳700、农乳602、农乳1602、宁乳33对斑马鱼胚胎的致死中浓度分别为16.44、21.13、55.86、8446、109.90、120.08 mg·L-1,其中NP-10对斑马鱼胚胎急性毒性最大,宁乳33毒性最低;随着染毒剂量的增加,斑马鱼胚胎孵化率逐渐降低,致畸率逐渐提高,六种表面活性剂显示出相似的趋势,处理浓度与胚胎孵化率(致畸率)之间存在剂量-效应关系;NP-10、OP-10、农乳700处理组均诱导斑马鱼胚胎出现躯干侧翻、游囊关闭、躯干弯曲症状;农乳602、农乳1602、宁乳33处理组出现躯干侧翻、游囊关闭症状.     

雌激素受体作为壬基酚的主要作用靶点导致机体免疫毒性

雌激素作为一类重要的性腺类固醇化学信使,已经被证实能够直接调节机体免疫反应,因此,一些具有拟雌激素特性的环境内分泌干扰物(endocrine disruptors,EDs),会通过影响雌激素相关信号通路对免疫系统产生干扰作用。壬基酚(nonylphenol,NP)作为典型的环境内分泌干扰物,已有大量的文献报道其通过拟雌激素特性或干扰雌激素的合成、分泌、转运以及与靶点的结合,破坏机体生殖功能以及神经-免疫-内分泌系统,影响整体生理平衡与稳定。近年来,NP对免疫系统的干扰作用逐渐引起重视,研究发现,NP暴露会引起小鼠免疫器官及免疫细胞的发育异常,并且会导致新生小鼠肝毒性,肝脏细胞内炎性因子TNF-α、IL-1β分泌增加。除NP作为配体干扰雌激素信号通路外,尚未发现其他明确的分子机制解释NP造成的免疫毒性。本综述主要结合近年来相关的实验结果,总结了NP对免疫系统的潜在影响及其可能的分子机制。     

催化臭氧氧化过程中溴酸盐的生成机制研究

以黄河下游某水厂滤后水为目标物,选择了9种催化剂,在间歇反应装置中研究了单独臭氧和催化臭氧氧化过程中溴酸盐（BrO 3-）的生成情况,结果表明,在催化臭氧氧化过程中,NiO、CuO、Fe3O4、Al2O3加入使BrO 3-质量分数分别降低34.0%、32.8%、29.2%、20.8%.选取Fe3 O4作为催化剂研究催化...     

Study on the control of high ore pass dust pollution by pre-injection foam dedusting technology in the ore bin

Environmental Science and Pollution Research - The impact airflow generated by ore unloading in the chute raises the dust carried by the ore itself and the floating dust, and then, the dust raised...     

Association between short-term exposure to ambient air pollution and number of outpatient Helicobacter pylori infection visits

Environmental Science and Pollution Research - Helicobacter pylori infection (HPI) is an important risk factor of gastrointestinal diseases, but factors leading to it are still not fully...