全氟辛烷磺酰胺在小麦和蚯蚓中的富集与转化

研究了不同培养介质和培养方式下全氟辛烷磺酰胺（PFOSA）在小麦、蚯蚓体内的生物富集和转化.结果表明：小麦根系可以从培养介质中吸收PFOSA并向上转运至茎叶.土壤中PFOSA生物有效性受总有机碳（TOC）的影响显著,高TOC含量土壤中PFOSA的生物有效性降低,导致其在小麦和蚯蚓中的生物富集因子分别由（61.24±8.42）和（21347.91±208.86）降至（5.61±0.23）和（1404.92±108.21）.PFOSA在小麦的根和茎叶以及蚯蚓中都可以转化为PFOS,但在蚯蚓中的转化率（（3.87±1.71）%）显著低于小麦（（26.39±3.02）%）.小麦根中PFOS的支链异构体（br-PFOS）比例在低、高TOC含量时分别为（14.8±2.0）%、（66.1±26.2）%,低于茎叶（分别为（63.0±21.3）%、（85.2±2.4）%））,可能是由于根部转化生成的br-PFOS更容易向茎叶转运.小麦特别是小麦茎叶中的br-PFOS比例（（85.2±2.4）%）显著高于蚯蚓（（16.5±4.0）%）.小麦的存在可以提高土壤中PFOSA的生物有效性,从而促进蚯蚓对PFOSA的富集,但对其转化影响不大.本文为小麦和蚯蚓中PFOSA的富集和转化提供了证据,有助于探索环境中PFOS的间接来源.     

泵群无线监测系统在石化装置中的应用

介绍了机泵无线监测系统的系统架构、监测方案,并结合具体诊断案例详细说明了其在某千万吨级炼化企业的应用情况。结果表明,该系统能准确评估机泵运行状态,并及时发布报警提示和维护建议,使用该系统事后维修占比由41%降到了15%,预知性维修由不足10%上升到近50%。     

Anaerobic oxidation of arsenite by bioreduced nontronite

The redox state of arsenic controls its toxicity and mobility in the subsurface environment. Understanding the redox reactions of arsenic is particularly important for addressing its environmental behavior. Clay minerals are commonly found in soils and sediments, which are an important host for arsenic. However, limited information is known about the redox reactions between arsenic and structural Fe in clay minerals. In this study, the redox reactions between As(III)/As(V) and structural Fe in nontronite NAu-2 were investigated in anaerobic batch experiments. No oxidation of As(III) was observed by the native Fe(III)-NAu-2. Interestingly, anaerobic oxidation of As(III) to As(V) occurred after Fe(III)-NAu-2 was bioreduced. Furthermore, anaerobic oxidization of As(III) by bioreduced NAu-2 was significantly promoted by increasing Fe(III)-NAu-2 reduction extent and initial As(III) concentrations. Bioreduction of Fe(III)-NAu-2 generated reactive Fe(III)-O-Fe(II) moieties at clay mineral edge sites. Anaerobic oxidation of As(III) was attributed to the strong oxidation activity of the structural Fe(III) within the Fe(III)-O-Fe(II) moieties. Our results provide a potential explanation for the presence of As(V) in the anaerobic subsurface environment. Our findings also highlight that clay minerals can play an important role in controlling the redox state of arsenic in the natural environment.     

Release and sedimentation behaviors of biochar colloids in soil solutions

The release of biochar colloids considerably affects the stability of biochar in environment. Currently, information on the release behavior and suspension stability of biochar colloids in real soil solutions is scarce. In this study, 20 soils were collected from different districts in China and the release behavior of biochar colloids and their suspension stability in soil solutions were systematically examined. The results showed that both pyrolysis temperature and biomass source had important effects on the formation of biochar colloids in soil solutions. The formation amount of biochar colloids from low pyrolysis temperatures (400 °C) (average amount of 9.33–16.41 mg/g) were significantly higher than those from high pyrolysis temperatures (700 °C) (average amount of less than 2 mg/g). The formation amount of wheat straw-derived biochar colloids were higher than those of rice straw-derived biochar colloids probably due to the higher O/C ratio in wheat-straw biochar. Further, biochar colloidal formation amount was negatively correlated with comprehensive effect of dissolved organic carbon, Fe and Al in soil solutions. The sedimentation curve of biochar colloids in soil solutions is well described by an exponential model and demonstrated high suspension stability. Around 40% of the biochar colloids were maintained in the suspension at the final sedimentation equilibrium. The settling efficiency of biochar colloids was positively correlated with comprehensive effect of the ionic strength and K, Ca, Na, and Mg contents in soil solutions. Our findings help promote a deeper understanding of biochar loss and stability in the soil-water environment.     

Core activated sludge communities are influenced little by immigration: Case study of a membrane bioreactor plant

Microbial immigrants arriving with influent wastewater may influence activated sludge (AS) ecosystems. However, the extent to which immigration impacts AS communities is still debated. To explore the intensity of immigration impact, we used sequencing technology to track the raw wastewater and AS communities from a membrane bioreactor plant over a 12-month period. We first distinguished core populations from peripheral ones in both raw wastewater and AS based on their occurrence frequency and abundance. The results showed that core OTUs (≥ 80% occurrence frequency) made up a large fraction (> 90%) of total sequences, while peripheral OTUs composed the majority of all detected OTUs but merely occupied a few sequences. A significant difference in core communities between the influent and AS was found, as well as between the compositions of core and peripheral populations. Additionally, the persistent functional bacteria of AS, although not numerically dominant, accounted for 96.24% of the total sequences related to nutrient turnover, suggesting the presence of a small number of longstanding and core functional bacteria in the AS ecosystem. Importantly, 64% of the 5188 OTUs in AS, which accounted for 91.51% of the sequences, exhibited positive growth rates, which suggested that their apparent abundances were due to growth within the plant, not from immigration. Taken together, these results demonstrated that the impact of influent populations on core AS communities was limited. Overall, this work provides quantitative insights into the impact of immigration, which is expected to advance our understanding of the AS community assembly.     

Interactions of extracellular DNA with aromatized biochar and protection against degradation by DNase I

With increasing environmental application, biochar (BC) will inevitably interact with and impact environmental behaviors of widely distributed extracellular DNA (eDNA), which however still remains to be studied. Herein, the adsorption/desorption and the degradation by nucleases of eDNA on three aromatized BCs pyrolyzed at 700 °C were firstly investigated. The results show that the eDNA was irreversibly adsorbed by aromatized BCs and the pseudo-second-order and Freundlich models accurately described the adsorption process. Increasing solution ionic strength or decreasing pH below 5.0 significantly increased the eDNA adsorption on BCs. However, increasing pH from 5.0 to 10.0 faintly decreased eDNA adsorption. Electrostatic interaction, Ca ion bridge interaction, and π-π interaction between eDNA and BC could dominate the eDNA adsorption, while ligand exchange and hydrophobic interactions were minor contributors. The presence of BCs provided a certain protection to eDNA against degradation by DNase I. BC-bound eDNA could be partly degraded by nuclease, while BC-bound nuclease completely lost its degradability. These findings are of fundamental significance for the potential application of biochar in eDNA dissemination management and evaluating the environmental fate of eDNA.     

The occurrence of per- and polyfluoroalkyl substances (PFASs) in fluoropolymer raw materials and products made in China

Perfluorooctanoic acid (PFOA), its salts, and related compounds were listed as new persistent organic pollutants by the Stockholm Convention in 2019. In this study, the occurrence of residues of PFOA and other per- and polyfluoroalkyl substances (PFASs) in raw materials and fluoropolymer products from the Chinese fluoropolymer industries are reported for the first time. The PFOA concentrations in raw materials and fluoropolymer products were in the range of 6.7 to 1.1 × 10⁶ ng/g, and <MDL (method detection limit) to 5.3 × 10³ ng/g, respectively. Generally, the levels of PFOA in raw materials were higher than in products, implying that PFOA in the emulsion/dispersion resin could be partly removed during the polymerization or post-processing steps. By tracking a company's polytetrafluoroethylene (PTFE) production line, it was found that over a 5 year period, the residual levels of PFOA in emulsion samples declined from 1.1 × 10⁶ to 28.4 ng/g, indicating that the contamination of PFOA in fluoropolymer products from production source gradually decreased after its use had been discontinued. High concentrations of HFPO-TrA (2.7 × 10⁵ to 8.2 × 10⁵ ng/g) were detected in some emulsion samples indicating this alternative has been widely applied in fluoropolymer manufacturing in China.     

海军直升机表面涂层体系改进研究

目的解决海军直升机表面涂层体系耐腐蚀性能较差,难以满足日历寿命要求的难题。方法采用新研制的有机涂层和原陆军直升机涂层分别对设计的结构模拟件进行涂装,并进行8个周期、共计200天的加速腐蚀试验,利用光泽度测量、色差测量和电化学阻抗测量的方法对涂层的腐蚀情况进行表征,考核验证涂层体系的防腐蚀性能。结果试验后新、原涂层外观基本完整,新涂层光泽度与色差无明显变化,原涂层光泽度下降较大。新涂层一直处于腐蚀初期的渗水阶段,其阻抗在10~8Ω·cm~2范围内,原涂层已进入腐蚀中期,其阻抗在10~6Ω·cm~2范围内。结论新涂层耐蚀性能更为优良,更加适用于海洋环境下的使用。     

Fe/污泥基生物炭持久活化过硫酸盐降解酸性橙G

利用污泥基生物炭（SDBC）固定铁物质制备了一种污泥基非均相催化剂（Fe-SDBC）,用于活化过硫酸盐（PS）以降解酸性橙G（OG）.Fe-SDBC/PS体系显示出对OG优异的降解性能.评价了影响降解的因素（Fe-SDBC金属负载量、Fe-SDBC投加量、初始pH值和PS浓度）.并通过X射线荧光光谱仪（XRF）、傅立叶变换红外分析仪（FT-IR）和拉曼光谱仪（Raman）对Fe-SDBC进行了表征.自由基清除剂实验表明,SO₄^·-和OH·自由基均在降解过程中生成,且活化PS历程主要发生在非均质催化剂表面.分析Fe-SDBC活化PS的潜在机理,表明不同形式的铁物质是PS分解的主要贡献者,Fe²⁺/Fe³⁺的转化循环提高了Fe-SDBC持久活化PS的效果.Fe-SDBC循环实验表明其对活化PS具有较好的可重用性,连续3次24h降解高浓度污染物仍能发挥作用.综上所述,Fe-SDBC作为一种污泥基非均相催化剂可以持久活化PS,从而实现OG的降解.     

山东省自然保护区管理状况调查与分析

基于自然保护区管理机构、人员配置、固定资产、事业经费、基建与生态工程投入、旅游收入等17项调查指标,系统调查了山东省自然保护区管理机构、人员配置和资金投入状况,定量分析了山东省自然保护区管理状况,论述了自然保护区管理存在的主要问题与对策。结果表明:山东省56%的自然保护区建立了专门的管理机构,63%的自然保护区现有人员数量低于25人,33%的自然保护区事业经费低于45万元。自然保护区管理存在的主要问题是管理机构不健全、人员配置不合理和资金投入不足。因此,山东省自然保护区管理应进一步完善管理机构,合理配置人员,增加资金投入。