水环境有机污染物预测的径向基函数网络模型

水环境中有机污染物的扩散迁移是一个由多种因素影响的复杂的非线性过程，根据河流有机污染物的浓度与其影响因素之间存在的映射关系，以实际监测数据为基础，建立了一个水环境有机污染物浓度预测的径向基函数网络模型，实例验证表明，该方法预测精度较高，具有一定的应用与推广价值。     

Determining reference conditions for TN, TP, SD and Chl-a in eastern plain ecoregion lakes, China

Establishing the nutrient reference condition(baseline environmental condition) of lakes in an ecoregion is a critical consideration in the development of scientifically defensible aquatic nutrient criteria.Three methods were applied to determine reference conditions in the Eastern plain ecoregion lakes with respect to total phosphorus(TP),total nitrogen(TN),planktonic chlorophyll a(Chl-a) and Secchi depth(SD).The reference condition value for the lakes in the Eastern plain ecoregion by the trisection method is TP of 0.029 mg/L,TN of 0.67 mg/L,Chl-a of 3.92 mg/m 3,SD of 0.85 m,and the reference condition range by the lake population distribution approach is TP of 0.014-0.043 mg/L,TN of 0.360-0.785 mg/L,Chl-a of 1.78-4.73 mg/m 3,SD of 0.68-1.21 m.Additionally,empirical models were developed for estimating the reference Chl-a concentration and SD successfully for lakes in the Eastern plain ecoregion.Overall,the data suggest that multiple methods can be used to determine reference conditions and that in Eastern plain ecoregion lakes the reference condition corresponds to a mesotrophic status.     

土壤可蚀性及其在侵蚀预报中的应用

土壤可蚀性是土壤侵蚀预报和土地利用规划的重要参数,国外已有物理意义明确、可操作性强、应用方便的土壤可蚀性定义和指标。国外的指标在我国不适用,而我国又没有这样的指标。在系统全面查阅和分析６０多年来已有研究成果的基础上,根据我国具体情况,提出我国土壤可蚀性指标的定义和测定方法,即在１５°坡度、２０ｍ坡长、清耕休闲地上,单位降雨侵蚀力所引起的土壤流失量。这一标准的确定对规范土壤可蚀性实验研究,促进我国土壤侵蚀预报模型的建立有重要意义     

Fenton试剂深度处理阿维菌素废水

采用Fenton试剂对阿维菌素废水好氧处理出水进行深度处理,通过正交和单因素试验,考察了初始反应pH值、H2O2投加量、FeSO4投加量和反应时间对废水COD去除率的影响。试验结果表明,最佳反应条件为初始反应pH值3.0、30%H2O2投加量5‰、0.5 mol/L FeSO4投加量1%和反应时间40 min,COD去除率达75%以上,出水ρ(COD)<120 mg/L,可满足GB 21903-2008《发酵类制药工业水污染物排放标准》表2的排放标准要求。     

低碳源条件下供氧模式对活性污泥系统脱氮性能的影响

通过对比采用连续曝气和间歇曝气两种供氧模式的活性污泥系统对低碳源污水的脱氮性能,探究低碳源条件下供氧模式对活性污泥系统脱氮性能的影响.结果表明,反应器进水C/N为3时,连续曝气系统的总氮去除率较间歇曝气系统高17.92%,碳源脱氮利用率较间歇曝气系统高44.29%,同时,连续曝气系统中反硝化菌相对丰度(5.86%)也高于间歇曝气系统(2.06%),说明连续曝气系统对低碳源污水的脱氮性能明显优于间歇曝气系统.另外,基于16S rRNA测序功能预测,连续曝气系统中微生物的膜输送功能、碳水化合物代谢功能以及细胞组成功能均强于间歇曝气系统,因此连续曝气系统中微生物可以更好地利用碳源生长代谢,进而更好地处理低碳源污水.本研究为应对城市污水处理厂进水碳源不足提供思路.     

国外几种道路交通噪声预测模式的对比分析

对美国的FHWA模式、英国的CoRTN模式和德国的RIS90模式进行了介绍，分析了现存模式的缺陷，指出了提高预测模式精度的途径。     

Effects of advanced oxidation pretreatment on residual aluminum control in high humic acid water purification

Due to the formation of disinfection by-products and high concentrations of Al residue in drinking water purification, humic substances are a major component of organic matter in natural waters and have therefore received a great deal of attention in recent years. We investigated the effects of advanced oxidation pretreatment methods usually applied for removing dissolved organic matters on residual Al control. Results showed that the presence of humic acid increased residual Al concentration notably. With 15 mg/L of humic acid in raw water, the concentrations of soluble aluminum and total aluminum in the treated water were close to the quantity of Al addition. After increasing coagulant dosage from 12 to 120 mg/L, the total-Al in the treated water was controlled to below 0.2 mg/L. Purification systems with ozonation, chlorination, or potassium permanganate oxidation pretreatment units had little effects on residual Al control; while UV radiation decreased Al concentration notably. Combined with ozonation, the effects of UV radiation were enhanced. Optimal dosages were 0.5 mg O3/mg C and 3 hr for raw water with 15 mg/L of humic acid. Under UV light radiation, the combined forces or bonds that existed among humic acid molecules were destroyed; adsorption sites increased positively with radiation time, which promoted adsorption of humic acid onto polymeric aluminum and Al(OH)3(s). This work provides a new solution for humic acid coagulation and residual Al control for raw water with humic acid purification.     

臭氧流化床深度处理焦化废水尾水过程中有机组分变化分析

焦化废水处理工程中,经过生物和混凝处理后,排放到环境中的尾水COD处于(85±20)mg·L-1范围内,这部分COD主要由一些难生物降解的物质构成,对水体环境造成污染,也给水回用带来了技术上的难度.为实现尾水中残留有机物的进一步削减,降低其在环境当中的危害,采用臭氧流化床反应器对焦化废水尾水进行深度处理并通过三维荧光光谱仪以及气相色谱/质谱(GC/MS)分析其水质组成的变化.结果表明:尾水在反应过程中,投加的臭氧量与降解的COD之间的比值(O3(kg)/COD(kg))随反应时间的延长不断增大;当pH=10时,COD、UV254和色度的去除率分别为51.5%,87.3%和85.0%,去除效果优于pH=7和pH=5条件下的反应;臭氧氧化能够有效分解尾水中类色氨酸、类溶解性微生物副产物、类腐植酸和类酪氨酸物质;经臭氧氧化后,焦化废水尾水中一些难生物降解的有机物得到了部分或完全去除,转化为一些新的有机物,如烷烃、苯甲醇、己酸等物质.研究结果证明,影响尾水的臭氧氧化效率涉及反应器结构、废水溶液性质和反应条件.     

斜坡滑动失稳演化的非线性机制与过程研究进展

文章对非线性动力学系统(NDS)理论在斜坡稳定性(岩石平面滑动斜坡和圆弧滑动土坡)和滑坡预报方面的研究进展作了评述,内容包括:滑面介质本构方程、失稳判据、水的作用机制、蠕变三阶段的理论解释、滑坡物理预报模型、预报指标与混沌模型的建立等,最后指出了进一步研究的方向与课题。     

情景分析法预测西安市大气污染物排放总量

情景分析法是通过对经济、技术的重大演变提出各种关键假设,对可能的未来情景加以描述,并分析情景对目标产生影响的预测方法。文章以西安市为例,运用情景分析法分析了2020年3种不同情景下的大气污染物排放量。结果显示:3种情景下SO2、NOx的排放量依次减小,情景二和情景三模式下的SO2排放量均低于基准年,但3种情景下的NOx排放量均高于基准年。