电-生物耦合技术对偶氮染料的去除研究

酸性大红GR是一种较难生物降解的偶氮染料,采用一种电场和生物耦合的新型技术处理酸性大红GR模拟废水,并与单纯电化学法和好氧生物法进行试验对照。结果表明：反应6 h后,电化学法、好氧生物法、电-生物耦合技术对酸性大红GR的去除率分别达到15.7%、25.8%和71.2%,电-生物耦合技术能明显提高酸性大红GR的去除效果,起到强化生物处理的作用。在15 mA微电流条件下电-生物技术能克服50 mg/L酸性大红GR对好氧生物处理的抑制作用,为高浓度难降解染料废水的生物强化处理提供了可能。     

HAZOP分析在常减压装置的应用及问题探讨

运用"HAZOP+LOPA+风险矩阵"复合式风险分析技术,对金陵分公司常减压装置进行危险辨识和风险分析,识别装置存在的主要问题和隐患,并对HAZOP技术应用中存在的适应性问题进行了探讨,对装置风险控制提出了针对性的建议措施,为装置的"安、稳、长、满、优"运行提供指导。     

Analysis of metabolic changes in Trichoderma asperellum TJ01 at different fermentation time-points by LC-QQQ-MS

Trichoderma spp. are among the most widely recognized biocontrol fungi used to inhibit pathogens and promote plant growth. These functions are related to primary and secondary metabolites. This study investigated the different metabolites in Trichoderma asperellum TJ01 cultured for 24 and 72?h using liquid chromatography with triple-quadrupole mass spectrometry. Compared to the 24?h culture of T. asperellum TJ01, the 72?h culture with amino acid metabolism tended to decrease while sugar and lipid metabolisms tended to increase. Furthermore, the 72?h culture had a higher proportion of upregulated flavonoids, in combination with a higher proportion of downregulated alkaloids, and equal proportions of upregulated and downregulated polyphenols and hormones. This study also identified a few valuable medicinal substances such as trigonelline and 5-hydroxytryptophan in T. asperellum TJ01 fermentation cultures.     

Biofiltration treatment of odors from municipal solid waste treatment plants

An in situ compost biofilter was established for the treatment of odors from biostabilization processing of municipal solid waste. The concentrations of total volatile organic compounds (VOCs) in odors and their components were measured. Biofilter media was characterized in terms of total carbon (TC), total nitrogen (TN), total phosphorus (TP), organic matter (OM), pH value and determination of bacterial colony structure. Gas chromatography–mass spectrometry (GC–MS) analysis showed that the main components of the produced gas were benzene, toluene, ethylbenzene and xylene (BTEX) along with other alkanes, alkenes, terpenes, and sulphur compounds. The compost biofilter had remarkable removal ability for alkylated benzenes (>80%), but poor removal for terpenes (～30%). Total VOC concentrations in odors during the biostabilization process period ranged from 0.7 to 87 ppmv, and the VOC removal efficiency of the biofilter varied from 20% to 95%. After about 140 days operation, TN, TC, TP and OM in compost were kept almost stable, but the dissolved N, NH₄–N and NO₃–N experienced an increase of 44.5%, 56.2% and 76.3%, respectively. Dissolved P decreased by 27.3%. The pH value experienced an increase in the early period and finally varied from 7.38 to 8.08. Results of bacterial colony in packing material indicated that bacteria and mold colony counts increased, but yeasts and actinomyces decreased along with biofilter operation, which were respectively, 3.7, 3.4, 0.04 and 0.07 times of their initial values.     

Modeling lead bioavailability and bioaccumulation by Lumbriculus variegatus using artificial particles. Potential use in chemical remediation processes

Artificial particles, specifically a diverse selection of chromatographical resins, have been recommended and used as a useful experimental model to predict the bioavailability and bioaccumulation of sediment-bound organic chemicals. In this work the same experimental model was adopted to investigate the bioavailability and bioaccumulation of lead by the freshwater oligochaete Lumbriculus variegatus. Particle-water partition coefficients were also determined. Sand particles and the anionic exchange resin promoted a similar uptake and bioaccumulation of lead. Instead, in the presence of the cationic exchanger the metal was not detected in the animals. For neutral particles, the uptake and accumulation depended on the chemistry of the functional groups at the active sites. In addition, a significant negative correlation was found between bioaccumulation and the particle-water partition coefficients. These studies may help to develop alternative methods for chemical remediation of lead-contaminated aquatic systems.     

Preparation of La-modified magnetic composite for enhanced adsorptive removal of tetracycline

Environmental Science and Pollution Research - Composite adsorbents usually outperform single component adsorbents as they could combine the properties and advantages of each component. In this...     

Quantitative evaluation of environmental risks of flotation tailings from hydrothermal sulfidation–flotation process

Floatation tailings (FT) are the main by-products of the hydrothermal sulfidation–flotation process. FT (FT₁ and FT₂) were obtained by treating two different neutralization sludges (NS) (NS₁ and NS₂). This paper quantitatively evaluated the environmental risks of heavy metals (Zn, Cd, Cu, Pb, and As) in FT versus NS. The total concentration and leaching rates (R ₂) of heavy metals in FT were much lower than those in NS, demonstrating that the hydrothermal sulfidation–flotation process was able to effectively suppress the mobility and leachability of heavy metals. The BCR-three sequence leaching procedure of FT confirmed that all metals were transformed into more stable forms (residue and oxidizable forms) than were found that in NS. The potential ecological risk index indicated that the overall risks caused by heavy metals decreased significantly from 6627.59 and 7229.67 (very serious risk) in NS₁ and NS₂, respectively, to 80.26 and 76.27 (low risk) in FT₁ and FT₂, respectively. According to the risk assessment code, none of the heavy metals in FT posed significant risk to the natural environment except Zn (with low risk). In general, the risk of heavy metals in FT had been well controlled.     

Distribution and source of microplastics in China's second largest reservoir - Danjiangkou Reservoir

Fresh water microplastic pollution is of pressing concern globally, but its distribution and sources in reservoirs are poorly documented. Danjiangkou Reservoir is the second largest reservoir in China and is divided into the Han Reservoir and Dan Reservoir. In this work, microplastic abundances and morphological characteristics of the reservoir were investigated. The microplastic abundance of 15 main tributaries of the reservoir was also measured. The vertical distribution (in water column and sediment), horizontal distribution (in Han Reservoir and Dan Reservoir) and source of microplastics were analyzed. Microplastics accumulated in the middle layer of the reservoir, and the size and color of the microplastic particles changed from the surface to the bottom, which implies that surveys of surface water are not enough to determine the microplastic contamination for deep water reservoirs. In the surface water, the microplastic abundance in the Han Reservoir was lower than that in the Dan Reservoir (p < 0.05), but microplastic abundance did not differ significantly in the intermediate and bottom water. Tributaries were one of the main sources of microplastics for Han Reservoir but not for Dan Reservoir. Agricultural cultivation in the hydro-fluctuation belt might be an important source of microplastics in the Dan Reservoir, which should be given additional attention. The results of this study can provide valuable information for developing microplastic sampling strategies in deep water reservoirs. Further studies are recommended to investigate the process through which microplastics in the hydro-fluctuation belt enter the reservoir and the sinking behavior of microplastics in the reservoir.     

废旧锌锰电池锌锰元素的分析表征

为了解废旧锌锰电池的锌锰元素特征,以废旧碱性(A-A)和酸性(Zn-C)电池为研究对象,采用化学分析、BCR连续萃取技术、SEM-EDS和XRD等手段对拆分的电池正、负电极材料中的锌锰元素进行了分析表征.实验表明:废旧碱性(A-A)电池中Mn、Zn分别占到正极材料质量的49.2%、10.3%,以Zn Mn2O4四方体锌锰矿结构晶体存在;Zn占负极材料的52.5%,以Zn O晶体存在;废旧酸性(Zn-C)电池混合电解质中,Mn、Zn各占41.8%和25.2%,分别以Zn Mn2O4、Mn O2、Zn5(OH)8Cl2·H2O和Zn(NH3)2Cl2等晶体存在.BCR处理结果显示,A-A电池正极和Zn-C电池混合电解质中,Mn主要为残渣态较难酸释,而A-A电池负极中的Zn易于回收.     

Iodine enrichment and the underlying mechanism in deep groundwater in the Cangzhou Region,North China

Environmental Science and Pollution Research - The lack of information on the origin and behavior of iodine in deep groundwater restricts the development and use of groundwater resources. To...