Nitrogen loss through lateral seepage in near-trench paddy fields

A near-trench paddy field experiment with five urea application rates (0-360 kg N ha(-1) in 90-kg increments) was conducted on a paddy soil in the Taihu Lake Region of China to elucidate N losses through lateral seepage during three rice (Oryza sativa L.) growing seasons. The total N (Nt), NH4(+) -N, and NO3(-) -N concentrations in the lateral seepage water increased with increasing N rates. The seasonal Nt fluxes by lateral seepage varied from 6.8 to 25.6 kg N ha(-1) for urea application rates of 90 to 360 kg N ha(-1). Lateral seepage accounted for 4.7 to 6.6% of the Nt applied, implying that lateral seepage was an important pathway of N loss from near-trench paddy fields. The cumulative N loss via lateral seepage was significantly related to N fertilization rate (P = 0.05). Floodwater level was also identified as a main factor affecting N losses via lateral seepage from paddy fields, as indicated by a positive linear relationship (R2 = 0.43) between floodwater level and daily lateral flow during the flooded period (P = 0.05). Under the conditions of these experiments, a shallow floodwater depth of 50 mm, urea application rates of 90 kg N ha(-1) or less, and no rainfall within 1 wk after N application reduced N losses by lateral seepage from paddy fields.     

自我意识的反射—司汤达的爱情和他的小说

爱情在司汤达的生活和创作中都占有极其重要的地位。本文以司汤达的《红与黑》和《红与白》为例，分析司汤达的“自我意识”在小说世界中的映现，将小说中的爱情描写和作家潜在的心理因素结合起来。《红与黑》印证了司汤达的爱情法则，而《红与白》中的爱情则是司汤达本人爱情经历的投射。     

Decomposition of nitrotoluenes from trinitrotoluene manufacturing process by Electro-Fenton oxidation

Oxidative degradation of dinitrotoluene (DNT) isomers and 2,4,6-trinitrotoluene (TNT) in spent acid was conducted by Electro-Fenton's reagents. The electrolytic experiments were carried out to elucidate the influence of various operating parameters on the performance of mineralization of total organic compounds (TOC) in spent acid, including reaction temperature, dosage of oxygen, sulfuric acid concentration and dosage of ferrous ions. It deserves to note that organic compounds could be completely destructed by Electro-Fenton's reagent with in situ electrogenerated hydrogen peroxide obtained from cathodic reduction of oxygen, which was mainly supplied by anodic oxidation of water. Based on the spectra analyzed by gas chromatograph/mass spectrometer, it is proposed that initial denitration of 2,4,6-TNT gives rise to formation of 2,4-DNT and/or 2,6-DNT, which undergo the cleavage of nitro group into o-mononitrotoluene, followed by denitration to toluene and subsequent oxidation of the methyl group. Owing to the removal of both TOC and partial amounts of water simultaneously, the electrolytic method established is potentially applied to regenerate spent acid from toluene nitration processes in practice.     

气升式内循环蜂窝陶瓷反应器高效快速修复地表水的研究

采用新型蜂窝陶瓷载体气升式内循环反应器(IAL-CHS)对受污染的城市地表水进行生物修复,该反应器能快速有效地修复受污染水体.考查了氨氮的变化历程、HRT与氨氮去除率间的关系,确定了最佳HRT为20 min.在HRT为20 min、接触反应时间仅为14 min条件下,该反应器对氨氮、TP、COD、TOC、浊度、UV254的去除率分别为86.7%～96.2%、4.5%～34.4%、15.5%～63.6%、5.8%～38.1%、9.4%～88.3%、3.8%～48.5%.     

A sensitive monoclonal antibody-based enzyme-linked immunosorbent assay for chlorpyrifos residue determination in Chinese agricultural samples

A monoclonal antibody-based competitive antibody-coated enzyme-linked immunosorbent assay (ELISA) was developed and optimized for determining chlorpyrifos residue in agricultural products. The IC₅₀ and IC₁₀ of this ELISA were 3.3 ng/mL and 0.1 ng/mL respectively. The average recoveries in six agricultural products were between 79.5% and 118.0%, with the intra-assay coefficient of variation being less than 8 %. The limit of detection for all tested products was 30 ng/g. To the best of our knowledge, this assay has the best specificity among all the published research on ELISAs for chlorpyrifos.     

市政污泥深度脱水药剂优化研究简

污泥含水率高影响污泥后续处置。利用化学药剂对污泥进行深度脱水处理可使污泥减量化、稳定化。为提高深度脱水效果，对添加剂进行了种类和添加量的优化研究（石灰、工业石灰、粉煤灰、硅藻土、十二烷基磺酸钠和飞灰；5%、10%、15%、20%、25%和30%），另外，还进行了复合投加实验。研究结果表明，石灰、工业石灰、粉煤灰的深度脱水效果最好；复合添加中，25%石灰+5%粉煤灰，20%石灰+10%粉煤灰，10%石灰+20%粉煤灰的深度脱水效果最好。5%的石灰或者工业石灰的添加剂量使干化污泥pH值达到12.25，粉煤灰、硅藻土、十二烷基磺酸钠和飞灰的添加对干化污泥pH值影响相对要小。     

灭菌预处理污泥及其滤液产氢发酵的比较研究

剩余污泥中的固态物质包含大量的蛋白质和多聚糖等有机质，一直被认为是一种具有潜力的生物制氢原料。灭菌预处理的剩余污泥会释放出大量的有机质，真空抽滤后去除掉污泥中固态物质得到滤液。将预处理污泥与滤液分别作为底物，接种产氢菌Pseudomonas sp. GZ1后产氢发酵。测定2种不同底物发酵反应过程中氢气的产量，以及底物的变化（SCOD、可溶性蛋白质、总糖、pH值）。实验结果表明，利用预处理后的污泥滤液作为底物能够有效提高氢气产量。滤液发酵的产氢量达到了4.44 mg H₂/g COD，比预处理污泥直接发酵提高了近3.3倍。本实验证明污泥中的固态物质在发酵过程中能释放出更多的营养物质，但实际上并不能被产氢菌有效地利用产生更多的氢气，并对其原因进行了探讨。     

根据具体情况优化EPA8310中色谱分离条件

运用Agilent（安捷伦）1200系列高效液相色谱和多环芳烃专用柱ZORBAX Eclipse PAH（4.6×250mm、5μm,P.N.959990-918,S.N.USPAB01066）,对16种多环芳烃化合物混合溶液进行分析,根据具体实验条件优化EPA8310中色谱分离条件并得到了更节省时间、分离效率更好的流动相梯度变化程序。     

河流水环境质量综合评价方法比较研究

提出了对河流水环境质量综合评价方法的基本要求，对水环境质量评价方法的现状进行了研究，并通过对各种方法的 比较，探讨了今后水环境质量综合评价方法的发展方向。