废旧手机电池中钴和锂的回收及再利用研究

废旧手机电池进行人工拆解后,将正极浸入N-甲基吡咯烷酮(NMP)中,使正极活性物质与铝箔分离.再利用酸浸-碱出方法回收正极活性物质中的钴和锂.确定最佳工艺参数为:0.8 molg·L-1的硫酸溶液,反应温度50℃,固液比1∶20g· L-1,水浴加热60 min.用饱和Na2CO3溶液沉淀锂得到Li2CO3,NaOH溶液将钴沉淀,400℃煅烧3h得到Co3 O4.按化学计量比将Co3O4与Li2CO3混合,预处理后700℃煅烧7h得到LiCoO2粉末.对再生的LiCoO2进行了结构和形貌测试,表明再生后生成了颗粒均匀、结晶度较好的LiCoO2.     

Inactivation, reactivation and regrowth of indigenous bacteria in reclaimed water after chlorine disinfection of a municipal wastewater treatment plant

Disinfection of reclaimed water prior to reuse is important to prevent the transmission of pathogens. Chlorine is a widely utilized disinfectant and as such is a leading contender for disinfection of reclaimed water. To understand the risks of chlorination resulting from the potential selection of pathogenic bacteria, the inactivation, reactivation and regrowth rates of indigenous bacteria were investigated in reclaimed water after chlorine disinfection. Inactivation of total coliforms, Enterococcus and Salmonella showed linear correlations, with constants of 0.1384, 0.1624 and 0.057 L/(mg·min) and R² of 0.7617, 0.8316 and 0.845, respectively. However, inactivation of total viable cells by measurement of metabolic activity typically showed a linear correlation at lower chlorine dose (0-22 (mg·min)/L), and a trailing region with chlorine dose increasing from 22 to 69 (mg·min)/L. Reactivation and regrowth of bacteria were most likely to occur after exposure to lower chlorine doses, and extents of reactivation decreased gradually with increasing chlorine dose. In contrast to total coliforms and Enterococcus, Salmonella had a high level of regrowth and reactivation, and still had 2% regrowth even after chlorination of 69 (mg·min)/L and 24 hr storage. The bacterial compositions were also significantly altered by chlorination and storage of reclaimed water, and the ratio of Salmonella was significantly increased from 0.001% to 0.045% after chlorination of 69 (mg·min)/L and 24 hr storage. These trends indicated that chlorination contributes to the selection of chlorine-resistant pathogenic bacteria, and regrowth of pathogenic bacteria after chlorination in reclaimed water with a long retention time could threaten public health security during wastewater reuse.     

如何确保实验室质量监督的有效实施研究

环境监测实验室涉及的监测项目广,监测的过程比较复杂,而且有些过程是难以追溯的,充分有效的质量监督能够加强对监测全过程进行控制,文章简要分析了环境监测活动中质量监督存在的问题、难以有效开展的原因,并从加强管理层的重视、质量监督员的素质及培养、质量监督计划的编制、质量监督的关键环节控制等方面详细论述了如何确保质量监督的有效开展,及时采取纠正或预防措施从而促进环境监测技术水平提高与质量管理体系的持续改进。     

合肥台短水准异常与周边地震活动分析

以合肥台跨郯庐断裂短水准数据为基础,结合华东地区中强震及安徽地区小震释放能量分析了历史测量资料在地震期间的变化,研究了辅助资料对测量资料的影响,得出:(1)降水虽可能造成敏感地块的断层形变异常,但在区域应力作用断层到一定强度时断层形变异常仍具有一定的前兆意义.(2)华东地区中强地震、安徽地区小震(群)与合肥台断层形变存...     

6种含氮杂环化合物对发光细菌的毒性研究

研究了吲哚，吡啶，喹啉，异喹啉、2-甲基喹啉和8-羟基喹啉6种含氮杂环化合物对发光细菌的急性毒性作用及上述物质两两混合对发光细菌的联合毒性作用。结果表明，上述物质对发光细菌的EC50分别为11．75、591．50、24．30、8．24、52．26和0．88mg／L，毒性由强至弱依次为8-羟基喹啉、异喹啉、吲哚、喹啉、2-甲基喹、吡啶。所有物质两两混合的联合毒性作用均表现为相加作用。     

Anthropogenic land use substantially increases riverine CO2 emissions

Carbon dioxide (CO₂) emissions from inland waters to the atmosphere are a pivotal component of the global carbon budget. Anthropogenic land use can influence riverine CO₂ emissions, but empirical data exploring cause-effect relationships remain limited. Here, we investigated CO₂ partial pressures (pCO₂) and degassing in a monsoonal river (Yue River) within the Han River draining to the Yangtze in China. Almost 90% of river samples were supersaturated in CO₂ with a mean ± standard deviation of 1474 ± 1614 µatm, leading to emissions of 557 - 971 mmol/m²/day from river water to the atmosphere. Annual CO₂ emissions were 1.6 - 2.8 times greater than the longitudinal exports of riverine dissolved inorganic and organic carbon. pCO₂ was positively correlated to anthropogenic land use (urban and farmland), and negatively correlated to forest cover. pCO₂ also had significant and positive relationships with total dissolved nitrogen and total dissolved phosphorus. Stepwise multiple regression models were developed to predict pCO₂. Farmland and urban land released nutrients and organic matter to the river system, driving riverine pCO₂ enrichment due to enhanced respiration in these heterotrophic rivers. Overall, we show the crucial role of land use driving riverine pCO₂, which should be considered in future large-scale estimates of CO₂ emissions from streams. Land use change can thus modify the carbon balance of urban-river systems by enhancing river emissions, and reforestation helps carbon neutral in rivers.     

三峡库区农村填埋垃圾渗滤液污染物含量评价

为了研究农村填埋垃圾渗滤液污染物含量和组成,选取了三峡库区10个垃圾填埋场渗滤液作为研究对象,对其无机阴离子、重金属含量及组成成分和pH值进行了分析.结果发现,垃圾填埋场渗滤液p H值均呈碱性,同时,SO_4~(2-)浓度均普遍高于Cl~-浓度.此外,受氧化还原电位和p H值的影响,呈现出NO_3~--N浓度NO_2~--N浓度的分布趋势.通过指数和单因子评价法对填埋垃圾的重金属含量进行了分析和评价.结果表明,Cr无污染现象,但Cd污染现象普遍十分严重,Pb、Zn和Cu污染则在不同的地点呈现出空间差异性.研究表明,三峡库区农村填埋垃圾特异性高,污染物来源构成差异性大.     

膜生物反应器中污染物去除途径及膜过滤性能

采用一体式悬浮生长型和附着生长型膜生物反应器(MBR)处理微污染水源水,主要考察了两种MBR对污染物的去除途径和膜过滤性能。结果表明,两种MBR对主要污染物高锰酸盐指数和NH4+-N均有良好的去处效果,去除率分别达到66%和94%以上。悬浮生长型MBR的去除效果稍强于附着MBR,因为前者的生物量要高于后者。两种MBR的生物去除和膜去除对去除效果都有重要贡献,而膜去除是获得良好的出水水质的保证。曝气量对两种MBR的污染物去除效果没有明显影响,一定范围内增大曝气量会提高生物去除的比例。悬浮生长型MBR的膜污染速率要比附着生长型快得多,但运行稳定后,两者的膜比通量大致相当。     

Natural and anthropogenic factors affecting the shallow groundwater quality in a typical irrigation area with reclaimed water,North China Plain

In this study, the hydrochemical characteristics of shallow groundwater were analyzed to get insight into the factors affecting groundwater quality in a typical agricultural dominated area of the North China Plain. Forty-four shallow groundwater samples were collected for chemical analysis. The water type changes from Ca·Na-HCO₃ type in grass land to Ca·Na-Cl (+NO₃) type and Na (Ca)-Cl (+NO₃+SO₄) type in construction and facility agricultural land, indicating the influence of human activities. The factor analysis and geostatistical analysis revealed that the two major factors contributing to the groundwater hydrochemical compositions were the water-rock interaction and contamination from sewage discharge and agricultural fertilizers. The major ions (F, HCO₃) and trace element (As) in the shallow groundwater represented the natural origin, while the nitrate and sulfate concentrations were related to the application of fertilizer and sewage discharge in the facility agricultural area, which was mainly affected by the human activities. The values of pH, total dissolved solids, electric conductivity, and conventional component (K, Ca, Na, Mg, Cl) in shallow groundwater increased from grass land and cultivated land, to construction land and to facility agriculture which were originated from the combination sources of natural processes (e.g., water-rock interaction) and human activities (e.g., domestic effluents). The study indicated that both natural processes and human activities had influences on the groundwater hydrochemical compositions in shallow groundwater, while anthropogenic processes had more contribution, especially in the reclaimed water irrigation area.     

Sorption and desorption of pymetrozine on six Chinese soils

Pymetrozine is a selective insecticide with a unique chemical structure and mode to control hemipteran and homopteran. While pymetrozine has brought great benefits to crop production by killing insects, its residues in soil may have a detrimental effect on environment. Therefore, it is of great importance to investigate its behaviors in soil. In this study, the sorption and desorption of pymetrozine on six Chinese soils were investigated using a batch equilibrium approach to understand its mobile behavior in the soils. Both sorption and desorption isotherms of pymetrozine were in good agreement with the Freundlich model. The sorption coefficient K_F varied between 3.37 and 58.32 mL∙g⁻¹ and the sorption isotherms were nonlinear, with 1/n ranging from 0.57 to 0.91. A regression equation was proposed to predict the sorption of pymetrozine on six different soil samples: log K_F = 4.3708 − 4.5709 × log (pH in 0.01mol·L⁻¹ CaCl₂) + 0.4700 × log OC% + 0.0057 × sand (%) + 0.0022 × CEC(clay), with R² = 0.9982. The organic carbon content of soil positively affected the sorption of pymetrozine, but soil pH had a negative effect on the sorption. Additionally, effects of CaCl₂ concentration, soil to solution ratio and pesticide form were investigated. The sorption was promoted with an increase in soil to solution ratio and a decrease in CaCl₂ concentration. The possible variation of the five formulated products of pymetrozine was also investigated.