螺形龟甲轮虫形态结构对环境变化的响应

以螺形龟甲轮虫为研究对象,于2015年7月至2018年12月,选取广东南澳岛及湖南常德中营养至中度富营养水体共14个样点进行采样,对螺形龟甲轮虫进行了形态特征测量分析.结果表明,水温是螺形龟甲轮虫形态变化最主要影响因子,且与背甲长、背甲宽、棘刺长度均呈显著负相关（P<0.01）.不同纬度条件下螺形龟甲轮虫形态参数差异显著,常德地区螺形龟甲轮虫个体显著大于南澳地区（P<0.05）.螺形龟甲轮虫形态存在显著季节性变化,各形态参数随季节波动呈现夏秋、冬春分化模式.螺形龟甲轮虫后棘刺长随水体营养程度增加而减小（F=159.4,P<0.01）,富营养条件下后棘刺长度占全长的比例减小（F=167.5,P<0.01）.研究结果表明,螺形龟甲轮虫棘刺长度可作为水质生物监测指标,并为研究全球气候变暖提供重要参考.     

中国钢铁行业CO2减排技术及成本研究

钢铁行业是我国主要的能源消费及CO₂排放行业,推动钢铁行业低碳绿色发展已成为实现我国碳达峰、碳中和的重要环节。为此,研究围绕能源结构调整、工艺结构优化、节能减排技术推广和CCUS技术应用4方面,通过设置基础情景、稳定发展情景和强化减排情景3类情景,利用边际减排成本曲线对我国钢铁行业34项减排技术的减排成本和减排潜力进行分析。结果表明:在稳定发展情景下,我国钢铁行业平均减排成本为433元/tCO₂,所有技术的总减排成本为2100亿元,总减排潜力为4.9亿t。在各项减排技术中,废铁-电弧炉炼钢具有较高的减排经济效益,其以较低的单位减排成本贡献了钢铁行业近50%的碳减排量。未来,我国应加快推进长流程炼钢向短流程炼钢的发展,推动钢铁行业生产工艺的结构性调整。     

An unusual high ozone event over the North and Northeast China during the record-breaking summer in 2018

Under the background of global warming, the summer temperature of the North and Northeast China (NNEC) has significantly increased since 2017, which was accompanied by the aggravated ozone (O₃) pollution. In 2018, the NNEC experienced a record-breaking summer of the past 40 years. Influenced by the abnormal high temperatures, a regional ozone event occurred on 2-3 August, over 63% of 79 selected cities in the NNEC were exposed to O₃ pollution, and the maximum value of MDA8 O₃ reached 268 μg/m³. Observations indicated that ozone concentrations agree well with the maximum temperature at 2 meters (MT2M) over NNEC with a correlation coefficient of 0.69. During the pollution episode, strong downdraft in the local high (35°N-42.5°N, 112.5°E-132.5°E; LH) over the NNEC created the favourable meteorological conditions for O₃ formation. By analyzing the horizontal wind and wave activity fluxes (WAFs) at 200 hPa, we found that the LH formation was resulted from the Rossby wave propagation from upstream along the mid-latitude Asian jet. The split polar vortex intrusion further strengthened the amplitude of the Rossby wave and reinforced the LH. Moreover, a secondary circulation between Typhoon Jongdari and the LH contributed to the enhanced LH with strong subsidence. On the other hand, the stratospheric intrusions under the deep subsidence also contributed to the enhanced surface O₃. In this study, the deep-seated meteorological dynamical mechanisms contributing to the abnormal high temperatures were investigated, which can lead to a better understanding of the regional O₃ pollution over NNEC under the global-warming background.     

Removal of antibiotic-resistant genes during drinking water treatment: A review

Once contaminate the drinking water source, antibiotic resistance genes (ARGs) will propagate in drinking water systems and pose a serious risk to human health. Therefore, the drinking water treatment processes (DWTPs) are critical to manage the risks posed by ARGs. This study summarizes the prevalence of ARGs in raw water sources and treated drinking water worldwide. In addition, the removal efficiency of ARGs and related mechanisms by different DWTPs are reviewed. Abiotic and biotic factors that affect ARGs elimination are also discussed. The data on presence of ARGs in drinking water help come to the conclusion that ARGs pollution is prevalent and deserves a high priority. Generally, DWTPs indeed achieve ARGs removal, but some biological treatment processes such as biological activated carbon filtration may promote antibiotic resistance due to the enrichment of ARGs in the biofilm. The finding that disinfection and membrane filtration are superior to other DWTPs adds weight to the advice that DWTPs should adopt multiple disinfection barriers, as well as keep sufficient chlorine residuals to inhibit re-growth of ARGs during subsequent distribution. Mechanistically, DWTPs obtain direct and inderect ARGs reduction through DNA damage and interception of host bacterias of ARGs. Thus, escaping of intracellular ARGs to extracellular environment, induced by DWTPs, should be advoided. This review provides the theoretical support for developping efficient reduction technologies of ARGs. Future study should focus on ARGs controlling in terms of transmissibility or persistence through DWTPs due to their biological related nature and ubiquitous presence of biofilm in the treatment unit.     

Co-metabolic and biochar-promoted biodegradation of mixed PAHs by highly efficient microbial consortium QY1

Polycyclic aromatic hydrocarbons (PAHs), typical representatives of the persistent organic pollutants (POPs), have become ubiquitous in the environment. In this study, a novel microbial consortium QY1 that performed outstanding PAHs-degrading capacity has been enriched. The degradation characteristics of single and mixed PAHs treated with QY1 were studied, and the effect of biochar on biodegradation of mixed PAHs and the potential of biochar in PAHs-heavy metal combined pollution bioremediation were also investigated. Results showed that, in single substrate system, QY1 degraded 94.5% of 500 mg/L phenanthrene (PHE) and 17.8% of 10 mg/L pyrene (PYR) after 7 days, while in PHE-PYR mixture system, the biodegradation efficiencies of PHE (500 mg/L) and PYR (10 mg/L) reached 94.0% and 96.2%, respectively, since PHE served as co-metabolic substrate to have significantly improved PYR biodegradation. Notably, with the cooperation of biochar, the biodegradations of PHE and PYR were greatly accelerated. Further, biochar could reduce the adverse impact of heavy metals (Cd²⁺, Cu²⁺, Cr₂O₇^2?) on PYR biodegradation remarkably. The sequencing analysis revealed that Methylobacterium, Burkholderia and Stenotrophomonas were the dominant genera of QY1 in almost all treatments, indicating that these genera might play key roles in PAHs biodegradation. Overall, this study provided new insights into the efficient bioremediation of PAHs-contaminated site.     

Application of FeIII-TAML/H2O2 system for treatment of fluoroquinolone antibiotics

Over the recent past, fluoroquinolone antibiotics (FQs) have raised extensive attention due to their potential to induce the formation of resistance genes and “superbugs”, thus various advanced oxidation techniques have been developed to eliminate their release into the environment. In the present study, the prototype tetraamido macrocyclic ligand (Fe^III-TAML)/hydrogen peroxide (H₂O₂) system is employed to degrade FQs (i.e., norfloxacin and ciprofloxacin) over a wide pH range (i.e., pH 6-10), and the reaction rate increases with the increase in pH level. The effect of dosage of Fe^III-TAML and H₂O₂ on the degradation of FQs is evaluated, and the reaction rate is linearly correlated with the added amount of chemicals. Moreover, the impact of natural organic matters (NOM) on the removal of FQs is investigated, and the degradation kinetics show that both NOM type and experimental concentration exhibit negligible influence on the oxidative degradation of selected antibiotics. Based on the results of liquid chromatography-high resolution mass spectrometry and theoretical calculations, the reaction sites and pathways of FQs by Fe^III-TAML/H₂O₂ system are further predicted and elucidated.     

Potential applications of porous organic polymers as adsorbent for the adsorption of volatile organic compounds

Volatile organic compounds (VOCs) with high toxicity and carcinogenicity are emitted from kinds of industries, which endanger human health and the environment. Adsorption is a promising method for the treatment of VOCs due to its low cost and high efficiency. In recent years, activated carbons, zeolites, and mesoporous materials are widely used to remove VOCs because of their high specific surface area and abundant porosity. However, the hydrophilic nature and low desorption rate of those materials limit their commercial application. Furthermore, the adsorption capacities of VOCs still need to be improved. Porous organic polymers (POPs) with extremely high porosity, structural diversity, and hydrophobic have been considered as one of the most promising candidates for VOCs adsorption. This review generalized the superiority of POPs for VOCs adsorption compared to other porous materials and summarized the studies of VOCs adsorption on different types of POPs. Moreover, the mechanism of competitive adsorption between water and VOCs on the POPs was discussed. Finally, a concise outlook for utilizing POPs for VOCs adsorption was discussed, noting areas in which further work is needed to develop the next-generation POPs for practical applications.     

Thermal defluorination behaviors of PFOS,PFOA and PFBS during regeneration of activated carbon by molten salt

• New method of mineralizing PFCs was proposed. • Activated carbon was regenerated while mineralizing PFCs. • Molten NaOH has good mineralization effect on PFOS and PFBS. Current study proposes a green regeneration method of activated carbon (AC) laden with Perfluorochemicals (PFCs) from the perspective of environmental safety and resource regeneration. The defluorination efficiencies of AC adsorbed perfluorooctanesulfonate (PFOS), perfluorooctanoic acid (PFOA) and perfluorobutanesulfonate (PFBS) using three molten sodium salts and one molten alkali were compared. Results showed that defluorination efficiencies of molten NaOH for the three PFCs were higher than the other three molten sodium salts at lower temperature. At 700°C, the defluorination efficiencies of PFOS and PFBS using molten NaOH reached to 84.2% and 79.2%, respectively, while the defluorination efficiency of PFOA was 35.3%. In addition, the temperature of molten salt, the holding time and the ratio of salt to carbon were directly proportional to the defluorination efficiency. The low defluorination efficiency of PFOA was due to the low thermal stability of PFOA, which made it difficult to be captured by molten salt.The weight loss range of PFOA was 75°C–125°C, which was much lower than PFOS and PFBS (400°C–500°C). From the perspective of gas production, fluorine-containing gases produced from molten NaOH-treated AC were significantly reduced, which means that environmental risks were significantly reduced. After molten NaOH treatment, the regenerated AC had higher adsorption capacity than that of pre-treated AC.     

活性炭常温吸附实验研究

活性炭因有较大的比表面积和经济易得性,常作为气体吸附法净化气体的吸附剂。SO2是大气环境质量指示的一个重要大气环境因子,其排放被严格控制。SO2的吸附受多种因素影响,本研究选取商品粒状活性炭作为样品,在常温、常压、相对湿度RH=0%、用SO2标气和N2模拟配制气体的条件下,进行了活性炭物理吸附SO2的穿透曲线和吸附容量的研究,结果显示该商品活性炭实验吸附穿透曲线和吸附容量随其颗粒直径的减小而增加,吸附曲线也由陡峭变平坦。所得实验结果为商品活性炭的使用提供实验数据支撑。     

Fabrication and characterization of lightweight aggregate prepared from steel mill sludge in one step

Journal of Material Cycles and Waste Management - The qualified green lightweight aggregate (LWA) was successfully prepared from steel mill sludge (SMS) and fly ash (FAS) in one step using the...