除草剂拉索对地下水影响研究

研究了除草剂拉索在滨海冲积沙壤中的残留及其对浅层地下水的影响，并用ＰＲＺＭ模型进行计算机模拟．两年连续试验结果表明，拉索在施药区内的浅层地下水中均有检出．在施药区外１０ｍ处，施药６０ｄ后亦有检出．降雨对其移动影响显著．拉索在土壤中残留动态的田间测定结果与计算机模拟基本一致．根据现有结果认为，拉索可在我国使用，但使用地区应作适当限制．     

Sorption of tylosin and sulfamethazine on solid humic acid

Tylosin(TYL) and sulfamethazine(SMT) are ionizable and polar antimicrobial compounds,which have seeped into the environment in substantial amounts via fertilizing land with manure or sewage. Sorption of TYL and SMT onto humic acid(HA) may affect their environmental fate. In this study, the sorption of TYL and SMT on HA at different conditions(pH, ionic strength) was investigated. All sorption isotherms fitted well to the Henry and Freundlich models and they were highly nonlinear with values of n between 0.5 and 0.8, which suggested that the HA had high heterogeneity. The sorption of TYL and SMT on HA decreased with increasing p H(2.0–7.5), implying that the primary sorption mechanism could be due to cation exchange interactions between TYL~+/SMT~+ species and the functional groups of HA.Increasing ionic strength resulted in a considerable reduction in the K_d values of TYL and SMT,hinting that interactions between H bonds and π–π EDA might be an important factor in the sorption of TYL and SMT on HA. Results of Fourier transform infrared(FT-IR) and ~13C-nuclear magnetic resonance(NMR) analysis further demonstrated that carboxyl groups and O-alkyl structures in the HA could interact with TYL and SMT via ionic interactions and H bonds,respectively. Overall, this work gives new insights into the mechanisms of sorption of TYL and SMT on HA and hence aids us in assessing the environmental risk of TYL and SMT under diverse conditions.     

Anaerobic digestion in mesophilic and room temperature conditions: Digestion performance and soil-borne pathogen survival

Tomato plant waste(TPW) was used as the feedstock of a batch anaerobic reactor to evaluate the effect of anaerobic digestion on Ralstonia solanacearum and Phytophthora capsici survival. Batch experiments were carried out for TS(total solid) concentrations of 2%, 4% and 6% respectively, at mesophilic(37 ± 1°C) and room(20–25°C) temperatures. Results showed that higher digestion performance was achieved under mesophilic digestion temperature and lower TS concentration conditions. The biogas production ranged from 71 to 416 L/kg VS(volatile solids). The inactivation of anaerobic digestion tended to increase as digestion performance improved. The maximum log copies reduction of R. solanacearum and P. capsici detected by quantitative PCR(polymerase chain reaction) were 3.80 and 4.08 respectively in reactors with 4% TS concentration at mesophilic temperatures. However, both in mesophilic and room temperature conditions, the lowest reduction of R. solanacearum was found in the reactors with 6% TS concentration, which possessed the highest VFA(volatile fatty acid) concentration. These findings indicated that simple accumulation of VFAs failed to restrain R. solanacearum effectively, although the VFAs were considered poisonous. P. capsici was nearly completely dead under all conditions. Based on the digestion performance and the pathogen survival rate, a model was established to evaluate the digestate biosafety.     

工业腐殖酸提纯前后对泰乐菌素的吸附特性

本文采用稀碱法对购买的工业腐殖酸进行了提纯,研究了腐殖酸提纯前后对泰乐菌素的吸附特性,并对其吸附机制进行了初步的探讨.研究结果表明:在对腐殖酸提纯之后,其C、H、O、N、S的含量明显增加,灰分含量显著减小.腐殖酸经提纯后对泰乐菌素的吸附明显增强,在24h可以完全达到吸附平衡,其吸附动力学曲线可以用拉格朗日二级动力学方程和颗粒扩散模型较好的拟合;吸附等温线可以用线性吸附模型和Freundlich吸附模型较好的拟合;且提纯后的腐殖酸对泰乐菌素的吸附随着溶液的p H值和离子强度增加而逐渐减小.综上,推测腐殖酸对泰乐菌素的吸附机制可能以疏水性分配、氢键作用和离子交换作用为主.     

便携式ＧＣ-ＭＳ测定空气中有毒物质的应用

文章介绍了便携式气相色谱-质谱联用仪(Gas Chromatograph-Mass Spectrometer,GC-MS)的结构原理,结合应急监测的需要,说明了仪器性能参数与分析操作模式,探讨了标准曲线的建立与验证。通过仪器的实际应用,指出该仪器能够解决应急监测中目前存在的对有机污染物难以快速定性、定量的问题。利用捕集浓缩器富集待测定空气中挥发性有机化合物(VOCs),可迅速判断出气体样品中的挥发性有机化合物组分,给出定量测定结果。并根据日常使用情况,总结了便携式GC-MS性能特点。     

单壁碳纳米管致昆明小鼠脑组织的氧化损伤

单壁碳纳米管(single walled carbon nanotubes,SWCNTs)是纳米材料研究关注的焦点之一.尽管如此,关于其神经毒性的研究相对较少.本研究将SWCNTs以不同的浓度(0 mg·kg-1·d-1,3.125 mg·kg-1·d-1,6.25 mg·kg-1·d-1,12.5 mg·kg-1·d-1),通过腹腔注射于Kunming小鼠体内.神经行为学实验(旷场实验)结果表明,在一定浓度的SWCNTs作用下,小鼠的情绪受到一定的影响,具有抑郁症的特征,出现移动能力下降,紧张等现象.同时小鼠脑部组织的活性氧族(reactive oxygen species,ROS)和丙二醛(malondialdehyde,MDA)水平升高(p0.05),还原型谷胱甘肽(glutathione,GSH)水平降低(p0.05),炎症因子白介素-1β(interleukin-1 beta,IL-1β)的水平升高(p0.05).组织学观察显示,随着染毒浓度的升高,脑海马锥体细胞的空泡化程度愈加明显,着色不均,锥体细胞顶状树突逐渐消失,细胞排列松散,尼氏小体消失.结论:一定浓度的SWCNTs可以导致小鼠脑组织发生病变,产生一定的神经毒性.     

滇池表层沉积物对磷的吸附特征

在室内模拟条件下,从滇池表层沉积物对磷的吸附动力学与热力学两个角度出发,研究了滇池沉积物对磷的吸附特征,同时探讨了不同磷形态对磷吸附特性的影响,结果表明:1滇池不同形态磷含量顺序为:有机磷钙(O-P)钙结合态磷(Ca-P)金属氧化物结合态磷(Al-P)残渣态磷(Res-P)可还原态磷(Fe-P)弱吸附态磷(NH4Cl-P);2沉积物对磷的吸附动力学过程分为2个阶段,即快吸附和慢吸附阶段.快吸附阶段主要发生在0~0.5 h内,而慢吸附阶段主要发生在0.5~4 h.滇池沉积物对磷的吸附过程主要在4 h内完成.3外海北部上覆水磷酸盐(SRP)浓度低于沉积物中磷的吸附/解吸平衡浓度(EPC0),可初步判断该区域沉积物有向上覆水体释放磷的风险.4不同区域沉积物磷的最大吸附量(Qmax)和总最大吸附量(TQmax)均以外海南部最大.5沉积物本底吸附态磷含量(NAP)与钙结合态磷(Ca-P)呈显著正相关关系(R2=0.5139,p0.05),而其他吸附特征参数与磷形态之间相关性均不显著.6与洱海、太湖等湖泊相比,滇池沉积物磷的本底吸附态磷(NAP)和最大吸附量(Qmax)均处于较高水平,磷污染较为严重.     

地质灾害管理信息系统

在地质灾害普查、勘查、防治、社会经济状况、统计信息等资料的基础上,设计出为决策提供服务的地质灾害管理信息系统,以便对地质灾害进行科学管理     

长江经济带经济增长进程中的水资源阻尼效应研究

为量化2000-2016年长江经济带水资源消耗量对经济增长的约束程度，本文在科布道格拉斯生产函数中加入水资源要素，构建改进的Romer增长阻尼模型进行实证分析。结果显示：①研究期内长江经济带水资源增长阻尼系数总体稳定，水资源对经济增长的约束作用程度经历了明显的强弱变化；②研究期内水资源增长阻尼显著降低并趋向平稳，说明水资源对长江经济带经济增长的约束作用减弱并逐渐稳定；③浙江、上海、江西等7个省份存在明显的水资源增长阻尼，区域差异显著。由此，本文建议：长江经济带各省市应提升水资源利用效率，同时加大资本投入、优化劳动力结构，在区域协调发展方面可构建水权交易机制，以期使长江经济带在水资源"大保护"约束下实现经济的持续发展。