大气环境质量现状评价模型存在的问题及改进——以沈阳大气指数模型为例

文章分析了几类大气环境质量现状评价模型各自存在的问题,针对这些问题,选择了较典型的沈阳大气指数模型,首先对原模型中参数进行修正,使其成为与当前执行的环境空气质量标准相对应的综合指数模型,其次,基于概率统计思想对模型进行改进,得到不同保证率下的大气环境质量现状评价模型,最后,运用SPSS软件进行实证分析,改进后模型得到的评价结果更能准确反映区域实际大气环境质量现状。     

Removal of humic acid from aqueous solution by cetylpyridinium bromide modified zeolite

Natural zeolite was modified by loading cetylpyridinium bromide (CPB) to create more e cient sites for humic acid (HA) adsorption. The natural and CPB modified zeolites were characterized with X-ray di raction, field emission scanning electron microscopy, Fourier transform infrared spectroscopy and elemental analysis. The e ects of various experimental parameters such as contact time, initial HA concentration, solution pH and coexistent Ca2+, upon HA adsorption onto CPB modified zeolites were evaluated. The results showed that natural zeolite had negligible a nity for HA in aqueous solutions, but CPB modified zeolites exhibited high adsorption e ciency for HA. A higher CPB loading on natural zeolites exhibited a larger HA adsorption capacity. Acidic pH and coexistent Ca2+ were proved to be favorable for HA adsorption onto CPB modified zeolite. The kinetic process was well described by pseudo second-order model. The experimental isotherm data fitted well to Langmuir and Sips models. The maximum monolayer adsorption capacity of CPB modified zeolite with surfactant bilayer coverage was found to be 92.0 mg/g.     

基于信息扩散理论的天然气发电风险预警技术研究

随着我国天然气发电比例的不断增加,天然气发电的安全问题逐渐引起人们的关注。为定量分析天然气发电的风险预警等级,针对风险评估过程中的小样本问题,引入信息扩散理论确定风险事故发生的概率,并结合故障类型及影响、危险度分析方法,建立了天然气发电风险预警的定量计算数学模型。以某天然气电厂燃气轮机系统为研究对象,将该厂燃气轮机2007—2014年所发生事故的统计数据作为观测样本,利用构建的风险预警数学模型并结合Matlab软件,计算得到该天然气电厂燃气轮机事故的发生概率以及不同事故模式下事故后果的严重度,最终确定该电厂燃气轮机系统的风险预警等级为Ⅲ级。与传统的安全预警方法相比,该风险预警技术更加客观有效。     

高密度沉淀池技术概述

高密度沉淀池(Densadeg)以其结构紧凑、处理效率高、出水水质稳定等特点,越来越多地被应用于城市污水一级强化处理和深度处理。本文主要介绍了高密度沉淀池的三种基本类型,重点阐述了RL型高密度沉淀池的工作原理及组成,以及污泥外部循环系统、高效斜板设置的特点;同时介绍了Densadeg的另一种运行方式:超高速沉淀池(ACTIFLO工艺),展望了高密度沉淀池的应用前景。     

浙江省“十二五”大气污染物排放增量不确定因素及对策研究

在"十二五"发展过程中,基于经济社会发展规划目标测算的污染物排放增量存在诸多不确定性,极有可能突破预期值,因此在满足社会经济发展规划基础上提出的减排目标可达性也存在一定风险。为确保浙江省"十二五"大气污染物减排目标顺利完成,从GDP、能源消费、机动车保有量等方面分析了可能影响浙江省"十二五"大气污染物排放增量的不确定因素,并从提高经济发展质量、实施煤炭总量控制、试行机动车总量控制、推进排污权有偿使用和交易等方面提出针对性控制对策。     

Adsorption of humic acid from aqueous solution on bilayer hexadecyltrimethyl ammonium bromide-modified zeolite

Surfactant-modified natural zeolites (SMNZ) with different coverage types were prepared by loading hexadecyltrimethyl ammonium bromide (HTAB) onto the surface of a natural zeolite. The adsorption behavior of humic acid (HA) on SMNZ was investigated. Results indicate that the adsorbent SMNZ exhibited a higher affinity toward HA than the natural zeolite. HA removal efficiency by SMNZ increased with HTAB loading. Coexisting Ca²⁺ in solution favored HA adsorption onto SMNZ. Adsorption capacity decreased with an increasing solution pH. For typical SMNZ with bilayer HTAB coverage, HA adsorption process is well described by a pseudo-second-order kinetic model. The experimental isotherm data fitted well with the Langmuir model. Calculated maximum HA adsorption capacities for SMNZ with bilayer HTAB coverage at pH 5.5 and 7.5 were 63 and 41 mg·g⁻¹, respectively. E2/E3 (absorbance at 250 nm to that at 365 nm) and E4/E6 (absorbance at 465 nm to that at 665 nm) ratios of the residual HA in solution were lower than that of the original HA solution. This indicates that the HA fractions with high polar functional groups, low molecular weight (MW), and aromaticity had a stronger tendency for adsorption onto SMNZ with bilayer HTAB coverage. Results show that HTAB-modified natural zeolite is a promising adsorbent for removal of HA from aqueous solution.     

SBR亚硝化快速启动过程中影响因子研究

在低DO条件下对SBR反应器实现快速亚硝化的途径及影响因素进行研究.控制反应器主要参数为：DO 0.15～0.40mg/L,pH值7.52～8.30,温度22.3～27.1℃,曝气时间为8 h.通过高、低氨氮浓度（245.28 mg/L与58.08 mg/L）交替进水的方式,经过57个周期（36 d）的稳定运行成功实现...     

化学镀镍废液的处理及再生技术研究进展

介绍了化学镀镍废液的产生和危害,综述了近年来国内外采用化学沉淀法、电解法、氧化还原法、萃取法、离子交换法、电渗析法等对化学镀镍废液进行处理及净化再生的技术研究进展,对各种方法的实用性进行了评价,并指出今后的发展方向。     

镉对小鼠免疫毒性研究

采用体内试验和体外试验方法,观察氯化镉对小鼠免疫功能的影响。免疫后不同时间,给小鼠一次灌胃30mg/kgCdCl2,未见对免疫功能产生明显影响。反复多次灌胃染毒14天,在0.3mg/ks/d组可见明显抑制小鼠脾淋巴细胞IgM－pFC,抑制率为42.1％。体外试验表明,12.5μmol/LCdCl2与淋巴细胞作用48h,25μmol/LCdCl2作用72h,对淋巴细胞增殖反应抑制率分别为38.3％和77.8％,以上结果表明氟化钢具有明显的免疫毒性。     

铬渣制取铬黄淋滤液中过量铅离子的去除研究

用累托石做吸附剂来处理铬渣淋滤液制铬黄过程中产生的过量Pb^2-。当pH为5．6～7．3,反应时间90min,吸附剂与水量比为24g／L.pbe^2 浓度由2．5mg／L降到0．05mg／L,Pb^2 的去除率最高可达98％,外排废水符合GB8978—1996一级标准。