发酵鸡粪和有机磷肥对土壤中Pb、Cd污染的影响

研究了湘西地区常用的发酵鸡粪和有机磷肥施用对不同程度Pb、Cd复合污染土壤中乙三胺五醋酸(DTPA)提取态Pb(DTPA-Pb)、DTPA提取态Cd(DTPA-Cd)和土壤酶的影响,并研究了对于种植黑麦草(Lolium perenne L.)的影响。结果表明:(1)施用发酵鸡粪和有机磷肥均能显著改善土壤酸性,一定程度上提高土壤有机质含量。在加入质量浓度200mg/kg总Pb、2mg/kg总Cd复合污染土壤中施用有机磷肥,能有效钝化土壤DTPA-Pb、DTPA-Cd,但在400mg/kg总Pb、4mg/kg总Cd复合污染土壤中钝化效果有限,其优先钝化DTPA-Pb。施用发酵鸡粪不能有效钝化土壤DTPA-Pb、DTPA-Cd。(2)施用发酵鸡粪和有机磷肥均显著提高黑麦草鲜重。虽然施用有机磷肥能更有效的钝化土壤DTPA-Pb、DTPA-Cd,但对于黑麦草种植而言,施用发酵鸡粪能更有效的降低其对Pb和Cd的积累,并且主要积累到根部。(3)施用发酵鸡粪对土壤碱性磷酸酶活性、脱氢酶活性和脲酶活性有显著的促进作用。综合而言,湘西地区种植牧草黑麦草,施用发酵鸡粪比较合适,能有效改善土壤酸性,提高黑麦草鲜重和土壤酶活性,降低黑麦草对Pb和Cd的积累。     

pH和温度对2,2’,4,4’-四溴联苯醚在土壤中吸附和解吸行为的影响研究

研究了pH和温度对2,2’,4,4’-四溴联苯醚(BDE-47)在土壤中的吸附和解吸行为的影响。结果表明,pH和温度都可以影响BDE-47在受试土壤中的吸附和解吸行为。pH升高或降低均会使土壤对BDE-47的吸附能力提高,且在碱性环境中提高的程度更大;酸性或碱性条件下BDE-47在土壤中的解吸滞后性显著增强。温度降低后,土壤对BDE-47的吸附能力提高,5℃时的单点分配系数(Kd,表征土壤对BDE-47的吸附能力)是25℃时的1.03~1.67倍;温度由25℃降低到5℃后,BDE-47在土壤中的解吸滞后性增强。     

Dynamic model based safety analysis of a three-phase catalytic slurry intensified continuous reactor

Safety analysis like the HAZOP (HAZard OPerability) study can be much more efficient if a dynamic model of the system under consideration is available to evaluate the consequences of hazard deviations and the efficiency of the proposed safety barriers. In this paper, a dynamic model of a three-phase catalytic slurry intensified continuous chemical reactor is used within the context of its HAZOP (HAZard OPerability) study. This reactor, the RAPTOR®, is an intensified continuous mini-reactor designed by the French company AETGROUP SAS that can replace batch or fed-batch processes in the case of highly exothermic reactions involving hazardous substances. The highly hazardous hydrogenation of o-cresol under high pressure and temperature is taken as an example of application. Deviations as a temperature increase of the cooling medium or no cooling medium flow can produce an overheating of the reactor. Thus, three possible safety barriers are evaluated by simulation: shut off the gaseous reactant feed, shut off the liquid reactant feed or stop the agitation. The more efficient actions are the stopping of the agitation and/or of the gas reactant feed. The simulation results can efficiently help the reactor design and optimisation. Safety analysis can also be one of the criteria to compare batch and intensified continuous processes.     

非饱和土壤渗透系数空间不确定性对溶质运移的影响

包气带渗透系数的不确定性是影响非饱和带溶质运移的主要因素。应用贝叶斯方法对非饱和土壤渗透系数进行前处理,使用Monte-Carlo方法模拟其空间不确定性,并通过HYDRUS-1D模型对溶质运移进行数值模拟,研究包气带渗透系数的空间不确定性对溶质运移的影响。结果表明,由于包气带渗透性的不确定性使得溶质浓度分布呈现明显的不确定性,包气带内不同点的浓度值相差很大。与忽略包气带土性参数空间不确定性的模拟结果相对比,考虑包气带渗透系数不确定性的模拟结果与实际情况更加接近,更具合理性和科学性。同时,根据模拟结果,对实际工作中进行地下水数值模拟时溶质初始浓度输入值的确定提出相应建议。     

微波辅助改性壳聚糖的制备及其絮凝性能

以壳聚糖、阳离子醚化剂二甲基二烯丙基氯化铵为原材料,采用微波辐射的方法,制备了壳聚糖接枝共聚物（壳聚糖-二甲基二烯丙基氯化铵）,并通过红外光谱分析对改性壳聚糖进行了表征。以接枝率为标准,确定改性壳聚糖的最佳反应条件,并以高岭土悬浊液和实际生活污水作为处理对象,测定了改性壳聚糖的絮凝性能。结果表明,壳聚糖接枝共聚物的最佳制备条件是微波反应温度55℃,反应时间20 min,壳聚糖0.5 g,微波功率270 W,阳离子醚化剂的浓度20%,在此条件下,合成的改性壳聚糖的接枝率为80%。红外光谱分析结果显示,已成功地合成了壳聚糖-二甲基二烯丙基氯化铵接枝共聚物。在絮凝实验中,壳聚糖接枝共聚物的去浊率最高达到91%,COD去除率最高达到77%。其结果表明,壳聚糖接枝共聚物的絮凝性能明显高于原料壳聚糖。     

重庆城区PM2.5化学组分特征及季节变化

2014年7月-2015年5月典型季节期间在重庆城区选择典型站点开展PM2.5样品采集,并测量质量浓度,分析样品中水溶性离子、无机元素、OC和EC等组分,在此基础上对组分化学组成进行了质量重构。结果表明：观测期间PM2.5年均值为76.4 μg·m-3,浓度季节变化为冬季 > 秋季 > 春季 > 夏季;组分方面,以二次转化为主的SO42-、NH4+、NO3-和OC是PM2.5组分中最主要成分,OC/EC比值4个季度均大于2,表明城区二次有机碳生成显著;硫氧化率（SOR）分析,气态污染物SO2的二次转化效率较高,大气存在明显的二次转化过程。PM2.5质量重构后主要组成为有机气溶胶（OM）、二次无机离子（SNA）和矿物尘,重庆城区应协同控制一次排放的颗粒物和气态污染物SO2和NOx,从而控制二次组分浓度。     

Modeling methyl isothiocyanate soil flux and emission ratio from a field following a chemigation of metam-sodium

Metam-sodium had become the most heavily used soil fumigant in recent years as the deadline approached for methyl bromide to phase out in January 2005. After application, metam-sodium decomposes rapidly to methyl isothiocyanate (MITC), a highly toxic compound capable of killing a wide spectrum of soil-borne pests. Inhalation risk of MITC ranked high among airborne agricultural pesticides in California. Information about off-gassing intensity and percentage of emission is essential for exposure risk assessment and mitigation measures, but is limited, especially for new application methods such as drip chemigation. Air concentrations of MITC were monitored around a field treated with metam-sodium through surface drip irrigation system. The field was tarped with plastic films before the chemigation. The air concentrations at receptor locations were simulated for the period of air monitoring with the Industrial Source Complex (ISC3) Dispersion Model, and soil flux density of MITC at various periods after chemigation was estimated through a back-calculation procedure. The estimated soil flux density of MITC showed a diurnal pattern, with the daytime flux stronger than nighttime. However, the average air concentration at nighttime was higher than that at daytime. Soil flux density peaked at 4.30 microg m-2 s-1 in the first 12-h period after chemigation, then declined with time. The MITC emission percentage in the first 60-h was 2.65% of applied mass, of which 57% occurred in the first 24-h after chemigation. The study indicated that the tarped bed drip application method of metam-sodium had a relatively good control of MITC emission from soil.     

我院电子阅览室利用情况分析

分别按专业、系部、年级、性别等方面统计了学生的开户情况，在不同的时间段调查了学生上机的目的，然后对学生在电子阅览室的开户情况和上机行为进行了深入分析，在此基础上，对我院电子阅览室的管理提出了几点建议。     

A multi-emission analysis of organic and inorganic pollutants during the combustion of sludge with high and low calorific value coals

Environmental Science and Pollution Research - To achieve allowable gas emission limits and eliminate the high cost and challenges associated with pre-treatment of sludge before incineration, a new...     

江苏省洪涝灾害评估系统设计

为了迅速、合理地预测和评估洪涝灾害造成的经济损失,为防汛决策提供科学依据,从江苏省洪涝灾害防治的实际需求出发,进行了江苏省洪涝灾情评估系统的总体设计,并阐明了系统的特点,结构和功能。