Ecotoxicological effects of polycyclic musks and cadmium on seed germination and seedling growth of wheat (Triticum aestivum)

Single and joint toxic e ects of polycyclic musks including 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta[g]-2- benzopyran (HHCB) and 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronapthalene (AHTN) and cadmium (Cd) on seed germination and seedling growth of wheat (Triticum aestivum) were investigated. The results showed that the toxicity sequence of HHCB toxic to wheat seed germination and seedling growth was similar to that of AHTN, that is, germination rate > shoot elongation > root elongation, while the toxicity of Cd was in the sequence of root elongation > shoot elongation > germination rate, according to the LC50 and EC50 values. It is suggested that polycyclic musks and Cd had di erent toxicological mechanisms. Root and shoot elongation of wheat might be good bioindicators for the contamination of polycyclic musks and Cd in soil. The mixture of polycyclic musks and Cd had synergistic e ects on T. aestivum according to the equi-toxic mixture approach when root elongation was selected as the toxicological endpoint. Thus, the joint toxicity of HHCB and Cd was significantly higher than the single toxicity of HHCB or Cd, which was also confirmed by the EC50 mix value of the mixture (EC50 mix = 0.530 TUmix). The EC50 mix value of the mixture of AHTN and Cd was 0.614 TUmix, which indicated that the mixture toxicity was strengthened when AHTN coexisted with Cd.     

Degradation and detoxification of microcystin-LR in drinking water by sequential use of UV and ozone

Microcystins (MCs) produced by cyanobacteria are strong hepatotoxins and classified as possible carcinogens.MCs pose a considerable threat to human health through tainted drinking and surface waters.Herein filtrated water from a waterworks in Harbin,China,was spiked with microcystin-LR (MC-LR) extracted from a toxic scum of microcystis aeruginosa,and the spiked sample waters were treated using UV irradiation with consequent ozonation process (UV/O3),compared with ozonation at a dose range commonly applied in water treatment plants,UV irradiation at 254 nm and UV irradiation combined with ozonation (UV+O3),respectively.The remaining of toxins were analyzed using high-performance liquid chromatography and also determined using a protein phosphatase type 2A inhibition assay,which was utilized to evaluate the reduction in toxicity.Results indicated that in comparison to other three processes (O3,UV,and UV+O3),UV/O 3 process could effectively decrease both the concentration and toxicity of MC-LR at 100 μg/L level after 5 min UV irradiation with consequent 5 min ozonation at 0.2 mg/L (below 1 μg/L),while 0.5 mg/L ozone dose was required for the level below 0.1 μg/L.The addition of an UV treatment step to the existing treatment train may induce significant transformation of micropollutants and breaks down the natural organic matters into moieties unfavorable for ozone decomposition,stabilizing the ozone residual.These findings suggested that sequential use of UV and ozone may be a suitable method for the removal of these potentially hazardous microcystins from drinking water.     

Carbonaceous particles in the atmosphere and precipitation of the Nam Co region, central Tibet

A continuous air and precipitation sampling for carbonaceous particles was conducted in a field observatory beside Nam Co, Central Tibetan Plateau during July of 2006 through January of 2007. Organic carbon (OC) was the dominant composition of the carbonaceous particles both in the atmosphere (1660 ng/m³) and precipitation (476 ng/g) in this area, while the average elemental carbon (BC) concentrations in the atmosphere and precipitation were only 82 ng/m³ and 8 ng/g, respectively. Very high OC/BC ratio suggested local secondary organic carbon could be a dominant contribution to OC over the Nam Co region, while BC could be mainly originated from Southern Asia, as indicated by trajectory analysis and aerosol optical depth. Comparison between the BC concentrations measured in Lhasa, those at “Nepal Climate Observatory at Pyramid (NCO-P)” site on the southern slope of the Himalayas, and Nam Co suggested BC in the Nam Co region reflected a background with weak anthropogenic disturbances and the emissions from Lhasa might have little impact on the atmospheric environment here, while the pollutants from the Indo-Gangetic Basin of Southern Asia could be transported to the Nam Co region by both the summer monsoon and the westerly.     

钻井废弃物治理技术的研究

阐述了东辛采油厂钻井废弃物来源及其处理现状,介绍了几种现有钻井废弃物处理工艺,在钻井废弃物治理技术上进行了探索与实践。     

改性兰炭末对硝基苯生产废水的吸附处理

采用H_2O_2溶液对兰炭末进行改性,并将改性后的兰炭末用于硝基苯生产废水(COD为560 mg/L)的吸附处理。对改性前后的兰炭末进行了表征,考察了吸附效果的影响因素,并对吸附前后改性兰炭末的燃烧热进行了测定。表征结果显示,兰炭末经改性后比表面积和孔径均增大。实验结果表明:在改性兰炭末投加量为0.2 g/m L、吸附时间为180 min、吸附温度为30℃的条件下,废水的COD去除率为93.4%,处理出水达到GB 8978—1996《污水综合排放标准》中规定的排放标准;改性兰炭末对废水中COD的吸附过程符合准二级动力学方程和Freundlich等温吸附模型;吸附后的改性兰炭末燃烧热值增大。     

环境规划中声环境管控分级研究——以长春市龙嘉机场为例

文章以长春市龙嘉机场为研究对象,结合机场参数指标,绘制机场噪声等值线图,并与城市规划相结合,评价机场周边噪声影响程度以及机场噪声对城市发展的限制作用.文章首先对机场周边56个噪声监测点位进行机场噪声数据采集,通过专业软件进行飞行事件分析,在飞行程序及飞行数据分析基础上,利用INM模拟软件进行机场模型构建,绘制机场噪声等值线图.结果表明,龙嘉机场Lwecpn 70以上区域总面积11.28平方公里,机场周边各类建设用地布局符合声环境标准当中土地用地的布局要求.     

铅冶炼企业废水治理新模式探讨

铅冶炼企业属于有色金属冶炼中的高污染行业,排放的废水属于重金属污染废水,有效的将冶炼废水进行规划处理是行业目前发展的趋势,本文通过对冶炼企业废水的来源和特性进行分类,找出适合铅冶炼企业废水循环利用的新途径,真正达到清洁生产的目的。     

呼和浩特市室内装修污染现状调查

对呼和浩特市60套新装修家居的室内空气污染现状的调查,发现该市新装修家居的室内空气污染情况比较严重,污染物以甲醛和TVOC为主。主卧甲醛的超标率为86.6%、TVOC的超标率为31.7%;客厅甲醛的超标率为43.3%、TVOC的超标率为5%;书房甲醛的超标率为66.6%、TVOC的超标率为25%;儿童房甲醛的超标率为70%、TVOC的超标率为18.3%。     

航空发动机涡轮叶片热障涂层冲蚀试验装置的研制

目的通过研制热障涂层冲蚀服役环境的模拟装置,来研究冲蚀失效机制。方法通过研制模拟热障涂层高温热冲击的燃气喷枪,在喷枪中设计速度、流量可控的颗粒送料系统,同时在装置中集成裂纹演化实时检测的声发射系统。结果该系统实现了热障涂层冲蚀服役环境的模拟,温度场、裂纹演化损伤参量的同步采集、输出与显示,从而完成了冲蚀服役环境模拟与关键损伤参量实时检测的一体化设计。结论装置能完成热障涂层常温、高温等各种服役温度、各种冲蚀角度、各种冲蚀速度等条件下的模拟试验,并提供较为系统的损伤参量检测数据,为理解热障涂层的冲蚀机理、优化其设计制备提供有效的试验数据。     

芳香烃含量对直喷汽油机颗粒物排放影响的试验研究

在一台增压中冷缸内直喷(GDI)汽油机上,开展了不同芳香烃含量的汽油对发动机颗粒物粒径分布和数量浓度影响的研究.结果表明,在正常热机工况下,随着负荷增加,核态颗粒物增加明显,颗粒物排放逐渐由三峰分布演变为双峰分布,并且芳烃含量高时,颗粒物排放明显增多.冷机工况及冷怠速时,芳烃含量对颗粒物的排放影响较小.和冷怠速相比,热怠速时颗粒物向小粒径方向移动,且颗粒物数量减少.热怠速时高芳烃含量的汽油排气中颗粒物相对较多.不同芳烃含量下,发动机参数对颗粒物排放会有一定影响,重芳烃含量高的汽油其颗粒物排放也高.