农药毒死蜱的生态风险及其微生物修复技术研究进展

毒死蜱是替代甲胺磷和对硫磷等高毒农药的高效有机磷杀虫剂,在世界范围得到广泛使用.但是,环境毒理学研究发现,毒死蜱对生态环境具有潜在的危险性,甚至被认为具有干扰内分泌的功能,许多国家对毒死蜱在农产品中的残留量有严格的规定.因此,深入研究毒死蜱的生态风险问题是当务之急.对国内外关于毒死蜱的残留活性、生态毒理、降解机制以及生物修复等方面的研究进行了综述,以期对毒死蜱的合理管理和使用提供科学依据.     

盘式曝气器的结构优化设计

盘式曝气器是目前城市污水处理厂主要采用的曝气设备之一.但目前盘式曝气器存在充氧能力低、阻力损失大、使用寿命短等技术问题,增加了城市污水处理厂运行成本,降低了运行效能.针对这些问题,对盘式曝气器进行了结构优化设计.通过结构优化,既改善了曝气器的抗撕裂性和自闭性,同时又提高了充氧能力,降低了曝气阻力损失.     

膨润土对Pb2+、Cu2+、Cr3+的吸附动力学及等温线研究

研究所用膨润土的主要成分为SiO2和Al2O3,属于Ca基膨润土,BET表面积为50.83 m2/g.在恒温及恒定pH条件下,用静态吸附法研究了膨润土对Pb2 、Cu2 、Cr3 的吸附特性,结果表明其较好地符合Lagergten二级吸附速率方程,对这3种离子的吸附速率为Pb2 ＞Cu2 ＞Cr3 .利用3种等温线方程对吸附过程进行拟合,发现利用Langmuir吸附等温方程计算的值与膨润土吸附Pb2 、Cu2 、Cr3 试验数据最为吻合.膨润土对3种金属离子的平衡吸附量为Cr3 ＞Cu2 ＞Pb2 .     

可张孔曝气器曝气能耗试验研究

通过试验研究,总结出可张孔曝气阻力损失的影响因素,以优化产品的结构设计参数,降低产品在工程应用中的能耗,获取更好的经济效益。     

Recolonization and succession of marine macrobenthos in organic-enriched sediment deposited from fish farms

High organic loading deposited on the sea bottom by marine fish farming activities often eliminates benthic organisms in the vicinity. In this study, organic-enriched sediment collected underneath a fish farm was defaunated, placed in settling trays and exposed to the subtidal area of a clean site of similar hydrography. Trays were sampled monthly for a consecutive period of 5 months, and recolonization and successional patterns of macrobenthos were studied using univariate and multivariate statistics. Recolonization occurred rapidly, and averages of 144 animals/tray and 26 species/tray were recorded within the first month. Molluscs accounted for 49% of species and polychaetes for 77% of abundance during the first month of recolonization. Temporal changes in abundance, diversity and species composition found in subsequent months resembled spatial changes of benthic community along a decreasing pollution gradient generalised by Pearson and Rosenberg (1978, Oceanography & Marine Biology Annual Review 16, 229-311). Abundance reached a peak after 3 months (434 animals/tray) and then declined. Species number also increased, peaked after 4 months (47 species/tray), and was followed by a decrease. The polychaete Prionospio malmgreni succeeded Pseudopolydora paucibranchiata as the dominant species after the first month, reached a peak (194 animals/tray) after 3 months, then declined sharply. The rapid recolonization and succession of the macrobenthic community on organic-enriched sediment suggested that present fish farming methods are unlikely to have a long-term impact on benthic communities once farming activities are reduced/ceased.     

Biodegradation of 2,4,6-trichlorophenol in the presence of primary substrate by immobilized pure culture bacteria

In this study, pure strains that are capable of utilizing 2,4,6-trichlorophenol have been isolated from the mixed culture grown on substrates containing chlorophenolic compounds. Studies have been carried out on the capability of these isolated pure strains in suspended and immobilized forms to decompose 2,4,6-trichlorophenol. Additionally, the influence of primary substrates (e.g., phenol, 2-chlorophenol, 3-chlorophenol, 4-chlorophenol, 2,4-dichlorophenol) on the decomposition of 2,4,6-trichlorophenol by the isolated pure strains grown in immobilized form is also investigated. The results are: Through bacterial isolation and identification, three pure strains have been obtained: Pseudomonas spp. strain 01, Pseudomonas spp. strain 02 and Agrobacterium spp. Whether in suspended or immobilized forms, all strains have poor removal efficiencies of 2,4,6-trichlorophenol. However, addition of 200 mg/l phenol will enable the immobilized Pseudomonas spp. strain 01, and Pseudomonas spp. strain 02 to achieve 65% and 48% removal of 2,4,6-trichlorophenol, respectively. Addition of phenol will assist the immobilized Pseudomonas spp. strain 02 in achieving removal of 2,4,6-trichlorophenol but the removal efficiency is not good if the phenol concentration is too low. The optimum phenol concentration should be between 200 and 400 mg/l.     

接种厌氧消化污泥EGSB反应器的快速启动

对接种市政消化污泥的EGSB反应器的启动进行实验研究以寻求快速启动EGSB反应器的有效方法。接种厌氧消化污泥EGSB反应器的成功启动仅需要46d。在整个启动期保持适当的液体上升流速是非常重要的。启动初期，高液体上升流速能够将悬浮污泥冲出反应器，使适合聚集的微生物留在反应器内。接下来需要降低进水流量和液体上升流速以利于构建稳定的微生态系统，使高活性颗粒污泥尽快形成。然后适当提高液体上升流速能保持污水与微生物的良好接触，促进颗粒污泥内外高效传质，形成更加稳定高效的微生物群落结构。为尽快形成高活性颗粒污泥，保证产甲烷菌的最佳营养需求是关键，可通过考虑进水基质、微量营养元素和硫化物来提高其活性。     

Did the Romans introduce the Egyptian mongoose (<Emphasis Type="Italic">Herpestes ichneumon</Emphasis>) into the Iberian Peninsula?

New finds of bones of the Egyptian Mongoose (Herpestes ichneumon), one from Portugal and one from Spain, were directly ¹⁴C dated to the first century AD. While the Portuguese specimen was found without connection to the Chalcolithic occupation of the Pedra Furada cave where it was recovered, the Spanish find, collected in the city of Mérida, comes from a ritual pit that also contained three human and 40 dog burials. The finds reported here show that the Egyptian mongoose, contrary to the traditional and predominant view, did not first arrive in the Iberian Peninsula during the Muslim occupation of Iberia. Instead, our findings are consistent with the hypothesis that the species was first introduced by the Romans, or at least sometime during the Roman occupation of Hispania. Therefore, radiocarbon dating of new archaeological finds of bones of the Egyptian Mongoose (Herpestes ichneumon) in the Iberian Peninsula push back the confirmed presence of the species in the region by approximately eight centuries, as the previously oldest dated record is from the ninth century. With these new dates, there are now a total of four ¹⁴C dated specimens of Egyptian mongooses from the Iberian Peninsula, and all of these dates fall within the last 2000 years. This offers support for the hypothesis that the presence of the species in Iberia is due to historical introductions and is at odds with a scenario of natural sweepstake dispersal across the Straits of Gibraltar in the Late Pleistocene (126,000–11,700 years ago), recently proposed based on genetic data.     

制革废水处理过程中磺胺类抗生素和抗性细菌的分布特征

针对两家制革厂废水处理过程中3种磺胺类抗生素和磺胺类抗性细菌的丰度和分布特性以及两个不同工艺污水处理厂对抗生素的去除规律做了相关研究.结果表明,3种抗生素在两家制革污水处理过程中均有检出,水样中3种抗生素的总质量浓度在59.1~706.7 ng·L~(-1)之间;两家制革厂废水处理剩余污泥中3种抗生素的总含量分别为4 388 ng·kg~(-1)和2 979.4ng·kg~(-1),与市政污水处理厂中的抗生素含量相差不大.不同的污水处理工段对3种抗生素去除效果不同,但去除效率均大于70%.生物处理单元对抗生素的去除率相对较高,而厌氧池是去除抗生素的主要阶段(去除率50%).两个制革厂的进出水和剩余污泥中共筛选出8株抗性细菌,这8个分离菌株可分为5个菌属.进出水中的抗性细菌含量介于9.37×10~3~5.08×10~5CFU·mL~(-1)之间,剩余污泥中的磺胺类抗性细菌含量较高分别为1.17×10`7CFU·g~(-1)和7.2×10~6CFU·g~(-1).两个制革污水处理厂对磺胺甲唑抗性细菌的去除率分别达到了1.34 log和2.15 log.