钝顶螺旋藻固定模拟烟道气中的CO2

研究了钝顶螺旋藻对模拟烟道气中CO2的固定性能,及其对NOx和SOx水溶形态亚硝态氮、亚硫酸氢根的耐受性。结果显示:随CO2浓度的增加,藻细胞达到最大比生长速率的时间缩短,CO2浓度为15%时藻细胞比生长速率达到最大的时间最短,生物量最终达到最大值4.1 g/L;CO2浓度为15%时藻细胞的固碳率为12.34 mg/(L·h)。研究发现,钝顶螺旋藻能够耐受浓度小于10 mmol/L的亚硝态氮,可将其作为钝顶螺旋藻生长的唯一氮源,但藻生长的延迟期增长。钝顶螺旋藻能够耐受8 mmol/L的亚硫酸氢盐,可将其作为生长的唯一硫源,藻细胞6 d后开始快速增长。     

好氧污泥对活性艳兰KN-G的吸附特性研究

实验研究了活性艳兰KN-G在好氧污泥上的吸附等温线和吸附动力学,考察了pH对好氧污泥吸附活性艳兰KN-G的影响。结果表明,好氧污泥对活性艳兰KN-G的吸附Freund lich和Langmu ir方程准确性较高,但是从模型的准确性和稳定性两方面考虑,Freund lich方程更适合描述好氧污泥吸附活性艳兰KN-G。应用伪一级、伪二级反应动力学和颗粒内扩散方程模型对实验数据进行验证,表明好氧污泥吸附活性艳兰KN-G更符合伪二级反应动力学模型。pH值对活性艳兰KN-G的吸附影响很大,pH值与吸附量呈负相关。     

蚕豆根尖微核技术监测环境污染物的诱变活性

应用蚕豆根尖微核技术对10份矿尘样品、黄曲霉毒素B_1(AFB_1)和15份真菌提取物进行诱变性研究,结果有10份矿尘、AFB_1和5种真菌提取物能明显诱发蚕豆根尖细胞微核率的增高;对其中5~#矿尘、AFB_1和杂色曲霉提取物进行剂量效应测定,显示了良好的剂量效应关系,提示具有诱变活性,这对当地的肿瘤发病率可能起重要作用。说明蚕豆根尖微核技术对研究环境诱变剂不失为一种有效的手段。     

原噬菌体诱导法在环境诱变剂研究中的应用

应用原噬菌体诱导法检测35种不同化学物质的潜在遗传毒性,S_9作代谢激活系统。试验结果有13个样品具有诱变性(占37.1％),其中有10个样品在S_9激活下和3个样品无论有与无S_9活化均能诱导溶源性大肠杆菌释放λ噬菌体。检出的阳性样品中有些为已知的诱变剂和致癌剂(黄曲霉毒素B_1)或抗癌药(丝裂霉素C)。提示诱导检测法作为环境遗传毒物的预警系统初筛潜在致癌危险物质是一种极为有用的手段。     

A novel use of anaerobically digested liquid swine manure to potentially control soybean cyst nematode

Experiments were carried out in two steps to determine the effect of anaerobically digested swine manure on soybean cyst nematode (SCN) egg control. In the first step, liquid swine manure underwent anaerobic digestion to search for the best digestion time for both volatile fatty acids (VFA) and ammonium nitrogen (NH(4)(+)) enrichment. The results showed that about 17 and 28 days of incubation were needed, respectively, to reach the maximal levels of VFA and NH(4)(+) in the manure. In the second step, raw, VFA-enriched, and NH(4)(+)-enriched manure were applied separately, at four different rates (25, 50, 100, and 200 mL/pot), to soil pots inoculated with nematode eggs in a greenhouse environment. Soil samples were collected 35 and 61 days after inoculation to determine the effect of such treated manure on SCN egg productivity. The data indicated that the SCN egg counts were inversely related to the manure application rates in a linear manner with correlation coefficients of 0.998, 0.967, and 0.900 for raw, NH(4)(+)-enriched, and VFA-enriched manure for the 35-day samples. While no such relationships were found for the 61-day samples, implying that none of the treatments were still effective 61 days after application. At the four application rates, the VFA-enriched manure performed best in reducing SCN egg counts (by 18.1, 19.5, 34.3, and 18.6%) as compared to the raw manure treatment. In contrast, the NH(4)(+)-enriched manure achieved mostly negative reductions. To achieve the best control of SCN egg growth, the VFA-enriched manure should be used and applied to soybean fields every 35 days.     

Biohydrogen production through fermentation using liquid swine manure as substrate

In this paper, continuous production of hydrogen through fermentation with liquid swine manure as substrate was researched using a semi-continuously fed fermenter (8 L in total volume and 4 L in working volume). The pH and temperature for the fermenter were controlled at 5.3 ± 0.1 and 35 ± 1°C, respectively, throughout the experiment. Three hydraulic retention times (16, 20, and 24 h) were investigated for their impact on the efficiency and performance of the fermenter in terms of hydrogen yields. The results indicate that hydraulic retention time (HRT) has a strong influence on the fermenter performance. An increasing HRT would increase the variation in hydrogen concentration in the offgas. To produce hydrogen with a fairly consistent concentration, the HRT of the fermenter should not exceed 16 h, which, however, did not appear to be short enough to control methanogenesis because the offgas still contained about 5% methane. When methane content in the offgas exceeded 2%, an inverse linear relationship between hydrogen and methane was observed with a correlation coefficient of 0.9699. To increase hydrogen content in the offgas, methane production has to be limited to below 2%. Also, keeping oxygen content in the fermenter below 1.5% would increase the hydrogen concentration to over 15%. The product to substrate ratio was found to be around 50% for the fermenter system studied, evidenced by the observation that for every 6 liters of manure fermented, 3 liters of pure hydrogen were produced, which was significant and encouraging.     

苏门答腊海域海啸地震及地壳深部结构

近10年来苏门答腊俯冲带大震频发,并引发灾难性海啸,使之成为全球关注的焦点。特别是2004年和2012年的两次大震所带来的科学问题在许多方面超出现有认识。国际上对苏门答腊地区已开展了大量的地质学、地球物理学等多方面的调查研究,应用了许多新方法并取得了许多新认识。解读苏门答腊的构造背景和地质演化史对于认识俯冲型大地震的产生机理是必要的,对此类地震的发生过程和规律的研究,对于理解海啸产生的条件和防灾减灾有十分重要的现实意义。本文对苏门答腊地区的地震活动和深部构造进行了详细分析,对近年关于该地区的世界性研究成果进行了总结,梳理出若干亟待研究的科学问题,进而提出开展苏门答腊俯冲带地震3D层析成像的具体实施路线。     

水质自动监测站运行管理常见问题和解决方法探讨

结合近几年常州市武进区省级水质自动监测站运行管理中的一些经验,对水质自动监测容易产生的问题进行介绍,同时对这些问题的解决方法和对策进行总结。