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361.
电化学处理黄姜生化尾水研究 总被引:1,自引:0,他引:1
黄姜提取皂素过程中会产生大量废水,传统的生化方法难以去除这些废水中的难降解有机污染物.因此,本文以黄姜皂素生化尾水为研究对象,分别采用DSA+铁电极组合、不锈钢+铁电极组合、单独钛钌网电极(DSA)对其进行深度处理.结果表明,在原水CODCr为150mg.L-1,色度为200度,Cl-浓度为3338mg.L-1的情况下,不锈钢+铁电极组合、单独DSA电极处理后CODCr去除率分别为35%和43%,色度去除率分别为78.7%和84.6%.相较而言,DSA+铁电极组合在电流密度为95A.m-2、初始pH=7.28时处理30min后,CODCr和色度的去除率分别达到62%和99.5%.采用紫外光谱、三维荧光光谱和凝胶色谱对水质变化进行了详细分析.结果表明,水中难降解有机组分被降解矿化,生成分子量较小的脂肪酸. 相似文献
362.
香港大气气溶胶组成与特征 总被引:4,自引:0,他引:4
选用香港空气质量监测网中11个监测站1990~1994年间TSP(总悬浮粒子)和RSP(可吸入悬浮粒子)的监测数据,分析香港大气气溶胶的化学组成与时空变化。香港大气气溶胶的浓度较低,其浓度的季节变化主要受气候变化的影响。C是大气气溶胶中最重要的化学成分,它支配着气溶胶的季节和空间变化。SO2-4、NH+4和NO-3的浓度很低,空间分布很均匀,其季节变化主要受东亚季风控制。海洋气溶胶主要以较大的颗粒形式存在,它的来源稳定且空间分布较均匀。扬尘浓度主要受降雨和湿度的影响。V和Ni浓度的季节变化与燃料油消耗量的季节变化相同,其空间的变化反映了当地工业窑炉排放对香港气溶胶的影响 相似文献
363.
364.
基于连续监测的城市内河返黑返臭机制初探:以南宁市二坑溪为例 总被引:1,自引:0,他引:1
黑臭水体严重危害城市生态功能,"水十条"的颁布为实现城市黑臭水体的污染整治目标制定了时间表.城市黑臭水体治理过程中,大量治理后的水体出现返黑返臭现象.为研究这一现象的原因,采用多参数水质检测仪和化学分析方法,对治理后返黑返臭的南宁市二坑溪水体进行了24 h连续监测和月度动态监测.结果表明,降雨过程与水体氨氮浓度相关性显著(P0.01),气温与水体氨氮浓度变化趋势正相关(r=0.23,P0.05),与水体透明度变化趋势负相关(r=-0.33,P0.01),显示治理后水体返黑返臭与内源污染物的微生物降解和外源污染物的输入有关.综上,为了防止治理后的城市黑臭水体返黑返臭,应当关注河道底泥等内源污染物及其控制技术,综合采取生态治理手段减少外源污染物输入,才能最终实现城市黑臭水体长效治理. 相似文献
365.
366.
Kang Sun Xingang Liu Jianwei Gu Yunpeng Li Yu Qu Junling An Jingli Wang Yuanhang Zhang Min Hu Fang Zhang 《环境科学学报(英文版)》2015
Size-resolved aerosol samples were collected by MOUDI in four seasons in 2007 in Beijing. The PM10 and PM1.8 mass concentrations were 166.0 ± 120.5 and 91.6 ± 69.7 μg/m3, respectively, throughout the measurement, with seasonal variation: nearly two times higher in autumn than in summer and spring. Serious fine particle pollution occurred in winter with the PM1.8/PM10 ratio of 0.63, which was higher than other seasons. The size distribution of PM showed obvious seasonal and diurnal variation, with a smaller fine mode peak in spring and in the daytime. OM (organic matter = 1.6 × OC (organic carbon)) and SIA (secondary inorganic aerosol) were major components of fine particles, while OM, SIA and Ca2 + were major components in coarse particles. Moreover, secondary components, mainly SOA (secondary organic aerosol) and SIA, accounted for 46%–96% of each size bin in fine particles, which meant that secondary pollution existed all year. Sulfates and nitrates, primarily in the form of (NH4)2SO4, NH4NO3, CaSO4, Na2SO4 and K2SO4, calculated by the model ISORROPIA II, were major components of the solid phase in fine particles. The PM concentration and size distribution were similar in the four seasons on non-haze days, while large differences occurred on haze days, which indicated seasonal variation of PM concentration and size distribution were dominated by haze days. The SIA concentrations and fractions of nearly all size bins were higher on haze days than on non-haze days, which was attributed to heterogeneous aqueous reactions on haze days in the four seasons. 相似文献
367.
为研究天津市春季道路扬尘PM_(2.5)和PM_(10)中碳组分特征及来源,于2015年4月用样方法采集天津市道路扬尘样品,利用再悬浮采样器将样品悬浮到滤膜上,经热光碳分析仪测定有机碳(OC)和元素碳(EC),利用非参数检验、OC/EC比值分析、相关分析及聚类分析对其污染特征和来源进行探讨.结果表明,PM_(2.5)中ω(TC)为4. 89%(次干道)~18. 83%(快速路),ω(OC)为3. 57%(次干道)~15. 39%(快速路),ω(EC)为1. 32%(次干道)~3. 44%(快速路); PM_(10)中ω(TC)为8. 14%(次干道)~19. 71%(快速路),ω(OC)为5. 91%(次干道)~16. 28%(快速路),ω(EC)为1. 96%(主干道)~3. 43%(快速路);快速路中各碳组分质量分数均较高,次干道中各碳组分质量分数均较低,可能是由于快速路中车流量较大,机动车尾气排放量较大,而次干道车流量较小;各类型道路中ω(OC)明显大于ω(EC),ω(EC)在不同道路类型中差异不大;两相关样本非参数检验表明,各碳组分质量分数在PM_(2.5)和PM_(10)间均无显著性差异;相关性分析表明道路扬尘中OC、EC来源大致相同.通过OC/EC比值分析及聚类分析可知,天津市春季道路扬尘中碳组分主要来源于燃煤、机动车尾气以及生物质燃烧. 相似文献
368.
Identification of causative compounds and microorganisms for musty odor occurrence in the Huangpu River, China 总被引:1,自引:0,他引:1
There are regular problems of musty odor in the Huangpu River,a major source of drinking water for Shanghai,China.In this study,the musty odor and its main causative compounds in the Huangpu River source water were confirmed through a yearly investigation using flavor profile analysis combined with HSPME-GC-MS analysis.The investigation showed that 2-methylisoborneol (2-MIB) with a concentration level between 28.6 and 71.0 ng/L was responsible for the musty odor in summer from July to September.Microscopic observation confirmed with the cloning results showed that Phormidium spp.,which accounted for 80%-95% of the algal cell density,was the microorganisms responsible for the production of 2-MIB and the estimated 2-MIB yield was 0.022 pg/cell.Results from a wide-area sampling campaign in the Huangpu River watershed showed that,other than the large tributaries receiving water from Tai Lake,several small creeks close to the intake may have contributed most of the 2-MIB and the Phormidium spp.to the Huangpu River source water.This study provides methodology for the investigation of odor causing compounds and microorganisms in river-type source water,and the result will be useful for water quality control in both source water and drinking water. 相似文献
369.
HUANG Hong LEE Shun-cheng CAO Jun-ji ZOU Chang-wei CHEN Xin-geng FAN Shao-jia 《环境科学学报(英文版)》2007,19(1):35-43
Quantitative information on mass concentrations and other characteristics, such as spatial distribution, seasonal variation, indoor/outdoor (I/O) ratio, correlations and sources, of indoor and outdoor PM2.5 and elemental components in Guangzhou City were provided. Mass concentration of PM2.5 and elemental components were determined by standard weight method and proton-induced X-ray emission (PIXE) method. 18 elements were detected, the results showed positive results. Average indoor and outdoor PM2.5 concentrations in nine sites were in the range of 67.7-74.5μg/m^3 for summer period, and 109.9-123.7 μg/m^3 for winter period, respectively. The sum of 18 elements average concentrations were 5362.6-5533.4 ng/m^3 for summer period, and 8416.8-8900.6 ng/m^3 for winter period, respectively. Average concentrations of PM2.5 and element components showed obvious spatial characteristic, that the concentrations in roadside area and in industrial plant area were higher than those in generic urban area. An obvious seasonal variation characteristic was found for PM2.5 and elemental components, that the concentrations in winter were higher than that in summer. The I/O ratio of PM2.5 and some elemental components presented larger than 1 sometimes. According to indoor/outdoor correlation of PM2.5 and element concentrations, it was found that there were often good relationships between indoor and outdoor concentrations. Enrichment factors were calculated to evaluate anthropogenic versus natural elements sources. 相似文献
370.
为研究伊犁河谷核心区春季大气细颗粒物(PM2.5)中无机元素、水溶性离子和碳组分特征和来源,于2021年4月20~29日在伊犁河谷核心区布设6个环境采样点,对PM2.5中水溶性离子、无机元素和碳组分等51种化学组分进行分析,并使用化学质量平衡(CMB)模型对其来源进行解析.结果表明,采样期间ρ(PM2.5)变化范围介于9~35μg·m-3.Si、 Ca、 Al、 Na、 Mg、 Fe和K等地壳元素占比较高,占PM2.5的12%,表明春季PM2.5受到明显的扬尘源的影响.富集因子结果表明,Zn、 Ni、 Cr、 Pb、 Cu和As元素主要来源于化石燃料燃烧和机动车排放.元素组分的空间分布特征受采样点周边环境的影响,新政府片区受燃煤源的影响较大,故As浓度较高,伊宁市局和第二水厂受机动车影响较大,Sb和Sn浓度较高.PM2.5中9种水溶性离子(WSIIs)的浓度占PM2.5的33.2%,其中ρ(SO2- 相似文献