2018—2021年安徽省PM2.5和O3时空分布特征及其健康风险分析

利用2018—2021年安徽省空气质量监测数据分析了PM_2.5和O₃时空分布特征及其引发的健康风险。结果表明:从时间分布来看,2018—2021年安徽省PM_2.5年均值下降25.5%,而O₃-8 h年均值则保持持平;PM_2.5和O₃-8 h月均值具有明显的季节变化特征,PM_2.5月均质量浓度和超标天数均在冬季达到最大值,O₃-8 h月均值和超标天数则在夏季达到最大值。从空间分布来看,PM_2.5、O₃-8 h年均值和超标天数均为皖北最高,其次为皖中,最后为皖南。夏季O₃是主要的健康风险因子,冬季PM_2.5是主要的健康风险因子。当PM_2.5超标时,除2021年皖北地区外(PM₁₀是主要的健康风险因子),PM_2.5均是主要的健康风险因子;当O₃-8 h超标时,O₃是主要的健康风险因子。     

Polymer Mineralization in Soils: Effects of Cold Storage on Microbial Populations and Biodegradation Potential

Soil retrieval, processing and storage procedures can have a profound effect on soil microorganisms. In particular, changes in soil microbial populations may adversely affect the biological activity of a soil and drastically alter the soil's potential to mineralize added substrates. The effects of cold storage on the biodegradation of a series of test polymers was investigated using two soils—a synthetic soil mix (SM-L8) and a field soil (Bridgehampton silt loam) from Rhode Island (RI-1). Biodegradation tests were conducted using freshly prepared/collected soil and again following storage at 4°C for 3 to 8 months. Prior to each biodegradation test, the soils were incubated at 60% water-holding capacity (WHC) and 25°C to rejuvenate the microbial populations; the soils were incubated for periods of 48 h (freshly collected soil) or 25 days (soils stored at 4°C). Soil microbial populations were assessed by enumerating different segments of the population on agar plates containing different selective media. Mineralization of the test polymers (cellulose, poly-3-hydroxybutyrate, and starch acetate, d.s. 1.5) was monitored using standard respirometric techniques. Our results demonstrated that cold storage had a generally negative effect on the soil microbial populations themselves but that its effect on the capacity of the soil microorganisms to degrade the test polymers varied between soils and polymer type. Whereas cold storage resulted in dramatic shifts in the community structure of the soil microbial populations, substantial restoration of these populations was possible by first conditioning the soils at 60% WHC and ambient temperatures for 25 days. Likewise, although the effects of cold storage on polymer mineralization varied with the test polymer and soil, these effects could be largely offset by including an initial 25-day stabilization period in the test.     

厌氧流化床反应器处理含硫废水毒性的实验

采用多孔聚合物载体固定化微生物在厌氧流化床（AFB）反应器中处理含硫废水,研究反应器抗硫化物（S^2－）毒性抑制和抗硫酸盐毒性抑制的能力;探索解除 S^2－毒性的方法．研究表明,当进料基质 COD浓度为 5000mg/L,HRT为5.2－5.4h,S^2－＜200mg/L时,反应器去除 COD效果不受影响,S^2－350mg/L时,厌氧消化受到明显抑制,反应器可容忍530mg/L S^2－浓度而未造成消化系统的破坏;SO₄^2－浓度高达3521mg/L,COD去除率仍可达77％－80％,但SO₄^2－去除率明显下降;当COD/SO₄^2－的比值大于1.45时,硫酸盐还原菌和产甲烷菌的生长未受到明显抑制,此时容积负荷为22－24kgCOD/（m³>·d）,COD去除率为80％,SO₄^2－去除率为58.8％;向反应器投加适量FeCl₂可很好地解除S^2－的抑制．     

复合式膜生物反应器处理高浓度氨氮废水可行性试验

试验结果表明,以甲壳素为载体的复合式膜生物反应器,在进水氨氮浓度为2100mg/L,氨氮容积负荷为2.19kg/(m3.d)时,氨氮去除率接近100%,系统运行稳定。载体投加量为2.778g/L时,膜通量可维持在87%左右。     

Importance of Habitat Quality and Landscape Connectivity for the Persistence of Endangered Natterjack Toads

Abstract: The natterjack toad (Bufo calamita) is endangered in several parts of its distribution, including Belgium, where it occurs mainly in artificial habitats. We parameterized a general model for natterjack population viability analysis (PVA) and tested its sensitivity to changes in the values of basic parameters. Then we assessed the relative efficiency of various conservation measures in 2 situations: a small isolated population and a system of 4 populations connected by rare dispersal movements. We based the population viability analysis on a stage‐structured model of natterjack population dynamics. We parameterized the model in the RAMAS GIS platform with vital rates obtained from our own field experience and from published studies. Simulated natterjack populations were highly sensitive to habitat quality (particularly pond drying), to dispersal from surrounding local populations, and to a lesser extent to values of fecundity and survival of terrestrial stages. Population trajectories were nearly insensitive to initial abundances, carrying capacities, and the frequency of extreme climatic conditions. The simulations showed that in habitats with highly ephemeral ponds, where premetamorphosis mortality was high, natterjack populations nearly always had a very high extinction risk. We also illustrated how low dispersal rates (<1 dispersing individual/generation) efficiently rescued declining local populations. Such source‐sink dynamics demonstrate that the identification and management of source populations should be a high priority.     

The Future of Scattered Trees in Agricultural Landscapes

Abstract: Mature trees scattered throughout agricultural landscapes are critical habitat for some biota and provide a range of ecosystem services. These trees are declining in intensively managed agricultural landscapes globally. We developed a simulation model to predict the rates at which these trees are declining, identified the key variables that can be manipulated to mitigate this decline, and compared alternative management proposals. We used the initial numbers of trees in the stand, the predicted ages of these trees, their rate of growth, the number of recruits established, the frequency of recruitment, and the rate of tree mortality to simulate the dynamics of scattered trees in agricultural landscapes. We applied this simulation model to case studies from Spain, United States, Australia, and Costa Rica. We predicted that mature trees would be lost from these landscapes in 90–180 years under current management. Existing management recommendations for these landscapes—which focus on increasing recruitment—would not reverse this trend. The loss of scattered mature trees was most sensitive to tree mortality, stand age, number of recruits, and frequency of recruitment. We predicted that perpetuating mature trees in agricultural landscapes at or above existing densities requires a strategy that keeps mortality among established trees below around 0.5% per year, recruits new trees at a rate that is higher than the number of existing trees, and recruits new trees at a frequency in years equivalent to around 15% of the maximum life expectancy of trees. Numbers of mature trees in landscapes represented by the case studies will decline before they increase, even if strategies of this type are implemented immediately. This decline will be greater if a management response is delayed.     

A Global Baseline for Spawning Aggregations of Reef Fishes

Abstract: Species that periodically and predictably congregate on land or in the sea can be extremely vulnerable to overexploitation. Many coral reef fishes form spawning aggregations that are increasingly the target of fishing. Although serious declines are well known for a few species, the extent of this behavior among fishes and the impacts of aggregation fishing are not appreciated widely. To profile aggregating species globally, establish a baseline for future work, and strengthen the case for protection, we (as members of the Society for the Conservation of Reef Fish Aggregations) developed a global database on the occurrence, history, and management of spawning aggregations. We complemented the database with information from interviews with over 300 fishers in Asia and the western Pacific. Sixty‐seven species, mainly commercial, in 9 families aggregate to spawn in the 29 countries or territories considered in the database. Ninety percent of aggregation records were from reef pass channels, promontories, and outer reef‐slope drop‐offs. Multispecies aggregation sites were common, and spawning seasons of most species typically lasted <3 months. The best‐documented species in the database, the Nassau grouper (Epinephelus striatus), has undergone substantial declines in aggregations throughout its range and is now considered threatened. Our findings have important conservation and management implications for aggregating species given that exploitation pressures on them are increasing, there is little effective management, and 79% of those aggregations sufficiently well documented were reported to be in decline. Nonetheless, a few success stories demonstrate the benefits of aggregation management. A major shift in perspective on spawning aggregations of reef fish, from being seen as opportunities for exploitation to acknowledging them as important life‐history phenomena in need of management, is urgently needed.     

甾体雌激素废水中优势降解菌的分离及特性

从某避孕药生产厂污水处理站好氧池活性污泥中通过富集驯化,分离到一株降解甾体雌激素(3-甲氧基-17a羟基-1,3,5(10),8(9)-雌甾-4-烯,简称MHE)的细菌ZY3菌株.经形态及16SrDNA序列分析初步鉴定,该菌株属于Raoultella属(Raoultellasp.).经过对ZY3菌株以MHE为唯一碳源生长和降解特性的分析表明,ZY3菌株利用MHE生长的最适温度和pH值分别为35℃和10.0,72h内的最适降解浓度为10mg/L.加入营养物质麦芽糖和蛋白胨能促进菌株对底物的降解,在72h内降解率达到了87%和85%.     

Al3+离子掺杂对负载TiO2薄膜光催化活性的影响

以钛酸丁酯和Al2(SO4)3·18H2O为原料,采用溶胶凝胶法在钛片、玻璃、釉面瓷砖、陶瓷、不锈钢和铝片六种载体上制备了Al3+掺杂TiO2薄膜,讨论了不同Al3+掺杂浓度下,不同载体表面上制备的TiO2薄膜对甲基橙脱色率的影响。试验结果表明Al3+对TiO2薄膜的掺杂效果与载体的类型密切相关,并且不同载体其Al3+掺杂的最佳浓度也不同。Al3+掺杂后,TiO2薄膜光催化活性提高最大的是玻璃,其次是釉面瓷砖、铝片、钛片、陶瓷,最差的是负载不锈钢。     

改性氧化铝微波诱导氧化处理雅格素蓝BF-BR染料废水的研究

采用微波诱导氧化工艺(MIOP)技术,以改性氧化铝为催化剂,对雅格素蓝BF-BR染料模拟废水进行氧化处理．优化了处理工艺条件,实验在固液质量比为1：10(50mL雅格素蓝BF-BR水溶液中投加5．0g改性氧化铝)、微波功率为400W的条件下微波辐照处理5min．在此工艺条件下,对水中雅格素蓝BF-BR的脱色率可达到98％,COD去除率为87．4％．改性氧化铝在重复使用9次后仍能保持很高的脱色率．进一步研究表明在微波辐射场中废水中的有机污染物在改性氧化铝表面通过吸附．氧化协同作用而被迅速降解．反应动力学研究表明,该氧化过程符合一级反应动力学规律,反应速率常数k=0995min^-1,反应半衰期t1/2=0．697min．实验结果显示,在本实验中改性氧化铝比颗粒活性炭具有更高的催化活性．