基于彗星实验的洛克沙胂对秀丽隐杆线虫胚胎细胞DNA损伤的研究

为评价洛克沙胂的遗传毒性,采用单细胞凝胶电泳(彗星实验),研究了不同浓度的洛克沙胂对秀丽隐杆线虫胚胎细胞脱氧核醣核酸(DNA)的损伤作用。提取秀丽隐杆线虫的胚胎细胞,分别暴露于0(空白对照)、50、250、500μg·L~(-1)含洛克沙胂的溶液染毒1 h。用彗尾DNA百分比含量(TDNA%)、彗星尾长(TL)和Olive尾矩(OTM)作为DNA损伤的指标。实验结果表明,与空白对照组比较,处理组中彗尾DNA百分比含量、彗星尾长以及Olive尾矩显著增加(P0.01)。随着洛克沙胂浓度的增加,彗尾DNA百分比含量、彗星尾长以及Olive尾矩逐渐增加,其相关系数r0.99,说明在实验浓度范围内,存在极显著的浓度-效应关系。洛克沙胂对秀丽隐杆线虫胚胎细胞DNA具有损伤作用,彗星实验操作简便、快速、灵敏度高,能够反映出洛克沙胂的遗传毒性。因此,通过彗星实验建立实验室检测洛克沙胂遗传毒性的方法具有可行性。     

苯系物联合暴露仿刺参管足转录组差异表达基因分析

为了分析苯系物(BTEXs)联合暴露后仿刺参(Apostichopus japonicus)管足转录组差异表达基因,采用Illumina Hi SeqTM2000测序技术,对1.0 mg·L~(-1)苯系物(B)联合暴露12 h后和对照组(C)的仿刺参管足组织分别进行转录组测序。经Trinity软件进行de novo组装,获得了145 675条unigenes。利用公共数据库进行同源比对,共注释了35 330条unigenes。对比分析苯系物联合暴露组和对照组的转录组测序结果,获得了2 418个差异表达基因(DEGs)(|Log2Fold changes|≥1且FDR≤0.001),其中,上调表达和下调表达基因分别为1 049和1 369个。GOseq分析结果显示,158个DEGs显著富集在149个GO terms中,包括103个生物学过程、17个细胞组分和29个分子功能(P0.05);KEGG代谢通路分析结果显示994个差异基因映射到268条代谢通路,这些差异表达基因参与的生理过程与其他生物的同源基因参与的信号传导、癌症、外源性化合物的生物降解代谢等过程相类似。上述结果为在转录组水平筛选苯系物的生物标志物,解析苯系物对仿刺参毒性作用的分子机制提供了科学参考。     

拉萨河放射性核素238U和232Th分布特征及健康风险评估

为了解拉萨河中放射性核素238 U和232 Th的污染水平及其对人类的致癌风险,利用拉萨河中下游和堆龙曲支流16个采样点水样的238 U和232 Th含量,采取美国环境保护局(U.S.Environmental Protection Agency,US EPA)推荐的放射性核素健康风险评价方法,评估不同年龄人群因饮水途径摄入核素的致癌风险.结果表明,拉萨河中238U和232Th平均活度浓度分别为(2.62±3.46)×10-2 Bq·L-1和(2.3±0.478)×10-3 Bq·L-1,比我国地表水平均值分别高31％和低61.7％;238U和232Th含量沿程分别呈波动稳定和波动变化的趋势;不同人群平均总致癌风险分别为(4.81±4.61)×10-8(幼儿组)、(2.29±1.81)×10-8(少年组)和(3.08±2.13)×10-8 a-1(成年组),均低于1×10-6 a-1(US EPA标准)和我国地表水平均致癌风险值,但对幼儿的致癌危害最大;238U和232Th的致癌风险贡献率随年龄的增长分别下降和上升;建议对羊八井镇附近河水进行持续监测,确保地热资源开发不会造成拉萨河放射性核素的污染.本研究不仅可以为拉萨河放射性核素污染的研究提供参考,而且可以为拉萨河未来的环境保护提供科学依据.     

Fabrication of highly efficient Bi2WO6/CuS composite for visible-light photocatalytic removal of organic pollutants and Cr(VI) from wastewater

• A novel Bi₂WO₆/CuS composite was fabricated by a facile solvothermal method. • This composite efficiently removed organic pollutants and Cr(VI) by photocatalysis. • The DOM could promoted synchronous removal of organic pollutants and Cr(VI). • This composite could be applied at a wide pH range in photocatalytic reactions. • Possible photocatalytic mechanisms of organic pollutants and Cr(VI) were proposed. A visible-light-driven Bi₂WO₆/CuS p-n heterojunction was fabricated using an easy solvothermal method. The Bi₂WO₆/CuS exhibited high photocatalytic activity in a mixed system containing rhodamine B (RhB), tetracycline hydrochloride (TCH), and Cr (VI) under natural conditions. Approximately 98.8% of the RhB (10 mg/L), 87.6% of the TCH (10 mg/L) and 95.1% of the Cr(VI) (15 mg/L) were simultaneously removed from a mixed solution within 105 min. The removal efficiencies of TCH and Cr(VI) increased by 12.9% and 20.4%, respectively, in the mixed solution, compared with the single solutions. This is mainly ascribed to the simultaneous consumption electrons and holes, which increases the amount of excited electrons/holes and enhances the separation efficiency of photogenerated electrons and holes. Bi₂WO₆/CuS can be applied over a wide pH range (2–6) with strong photocatalytic activity for RhB, TCH and Cr(VI). Coexisiting dissolved organic matter in the solution significantly promoted the removal of TCH (from 74.7% to 87.2%) and Cr(VI) (from 75.7% to 99.9%) because it accelerated the separation of electrons and holes by consuming holes as an electron acceptor. Removal mechanisms of RhB, TCH, and Cr(VI) were proposed, Bi₂WO₆/CuS was formed into a p-n heterojunction to efficiently separate and transfer photoelectrons and holes so as to drive photocatalytic reactions. Specifically, when reducing pollutants (e.g., TCH) and oxidizing pollutants (e.g., Cr(VI)) coexist in wastewater, the p-n heterojunction in Bi₂WO₆/CuS acts as a “bridge” to shorten the electron transport and thus simultaneously increase the removal efficiencies of both types of pollutants.     

The source and transport of bioaerosols in the air: A review

• Emission of microbe from local environments is a main source of bioaerosols. • Regional transport is another important source of the bioaerosols. • There are many factors affecting the diffusion and transport of bioaerosols. • Source identification method uncovers the contribution of sources of bioaerosols. Recent pandemic outbreak of the corona-virus disease 2019 (COVID-19) has raised widespread concerns about the importance of the bioaerosols. They are atmospheric aerosol particles of biological origins, mainly including bacteria, fungi, viruses, pollen, and cell debris. Bioaerosols can exert a substantial impact on ecosystems, climate change, air quality, and public health. Here, we review several relevant topics on bioaerosols, including sampling and detection techniques, characterization, effects on health and air quality, and control methods. However, very few studies have focused on the source apportionment and transport of bioaerosols. The knowledge of the sources and transport pathways of bioaerosols is essential for a comprehensive understanding of the role microorganisms play in the atmosphere and control the spread of epidemic diseases associated with them. Therefore, this review comprehensively summarizes the up to date progress on the source characteristics, source identification, and diffusion and transport process of bioaerosols. We intercompare three types of diffusion and transport models, with a special emphasis on a widely used mathematical model. This review also highlights the main factors affecting the source emission and transport process, such as biogeographic regions, land-use types, and environmental factors. Finally, this review outlines future perspectives on bioaerosols.     

粉料无尘装车技术的应用及发展

传统除尘器卸灰、输灰系统存在工艺繁杂、能耗大、输送速度慢、设备故障率高、系统难以维护及二次扬尘等问题,采用新型粉料无尘装车技术可有效简化工艺,提高生产速度和系统运行、维护可靠性,很大程度上减少能耗并彻底根除二次扬尘。     

GPRS在污水处理中的应用

介绍了将GPRS应用于污水处理行业中的好处,采用GPRS无线猫以无线的方式传输数据的优势：资费便宜,计费合理,设备投资低,新增和改变网点非常方便,线路稳定,接入速度快,而且永远不会掉线.最好地支持了频繁的或少量突发型的数据业务.     

臭氧-生物活性炭系统处理印染废水低温启动研究

为探讨低温条件下臭氧-生物活性炭系统处理印染废水的挂膜启动方法,采用臭氧氧化、活性炭吸附、生物氧化、活性炭生物再生共同作用,对印染废水二级处理出水进行深度处理。实验结果表明:低温条件虽然延长了系统的挂膜启动时间,但不影响挂膜质量,22 d后挂膜启动完毕,浊度、色度、COD去除率分别为68.76%、73.2%、60%,出水水质良好且稳定。     

松嫩平原玉米带农田表层土壤有机碳储量和固碳潜力研究

农田土壤有机碳储量和固碳潜力是陆地碳循环和全球气候变化研究中的一个重要问题。论文基于第二次土壤普查数据和实地取样数据,利用土壤类型法估算松嫩平原玉米带农田表层土壤有机碳储量,分析4个县市(德惠市、九台市、农安县、公主岭市)农田表层土壤碳库的饱和水平和固碳潜力,比较旱田与水田土壤固碳潜力的差异。结果表明,1980-2005年间,松嫩平原玉米带农田土壤有机碳储量增加了7.20 TgC。各县市农田土壤碳库的饱和水平以德惠市最大,为4.11 kgC·m^-2,九台市次之,公主岭市最低,为3.14 kgC·m^-2。假设在1980年土地利用方式、耕作措施、施肥水平和气候条件不变的情况下,估算得到松嫩平原玉米带农田土壤的固碳潜力为8.17 TgC。从单位面积固碳潜力看,九台市最高,为0.77 kgC·m^-2,农安县次之,德惠市和公主岭市均低于松嫩平原玉米带。松嫩平原玉米带旱田和水田土壤碳库的饱和水平基本持平。     

姬松茸中Cu,Zn,Ag,Cd和Hg累积特性的初步研究

对三种不同产地的姬松茸子实体,经过微波消解后,采用电感耦合等离子体发射光谱法(ICP- OES)、原子吸收光谱法(AAS)和原子荧光光谱法(AFS)测定了其中Ag,Al,As,Au,B,Ba,Bi,Ca,Cd,Cr,Co,Cu,Fe,Hg,K,La,Mg,Mn,Mo,Na,M,P,Pb,Rb,S,Sb,Se,Sn,Sr,Ti,V和Zn等32种元素的含量,并用高效液相色谱和电感耦合等离子质谱联用技术(HPLC-ICP-MS)分析了其中Hg元素的形态.另外,还探讨了Cu,Zn,Ag,Cd,Hg及一些相关元素在姬松茸子实体不同部位的分布特征.研究表明:与一些常见种类的大型真菌相比,姬松茸对Cu,Zn,Ag,Cd,Hg具有较强的累积能力,累积的Hg主要以Hg~(2 )形态存在,CH_3Hg~ 占总Hg比例在15%以下.Cu,Zn,Ag,Cd和Hg在姬松茸子实体不同部位的分布特征为:从菌柄下部到上部、从菌盖中心到边缘元素含量逐渐增加;P有助于提高姬松茸对Cu,Zn,Ag,Cd,Hg的累积能力,而Ca似乎起拮抗作用.