鼓风曝气系统氧利用率和动力效率的研究

研究了影响鼓风曝气系统氧利用率Eo 和动力效率Ep 的因素 ,给出了Eo 和Ep 与诸影响因素间的定量关系式。在鼓风曝气系统中 ,恰当地选取曝气器的浸没深度h和所产生气泡直径db 的组合 ,既可使氧气利用率高 ,又可使动力消耗少。这一结果对于指导曝气装置的设计和降低废水处理的能耗具有重要意义     

Environmental change in Bashang region historical periods

ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅＢａｓｈａｎｇｒｅｇｉｏｎｉｓｓｉｔｕａｔｅｄａｔｅａｓｔｌｏｎｇｉｔｕｄｅ113°50′-118°00′ａｎｄｎｏｒｔｈｌａｔｉｔｕｄｅ40°58′-42°42′,ｗｉｔｈａｎａｒｅａｏｆ17371ｋｍ2ｆｒｏｍＺｈａｎｇｊｉａｋｏｕｏｆｎｏｒｔｈｅｒｎＨｅｂｅｉｔｏｔｈｅｎｏｒｔｈｏｆＣｈｅｎｇｄｅ.ＴｈｅｒｅｇｉｏｎｌｉｅｓｉｎｔｈｅｍｉｄｄｌｅｓｅｃｔｉｏｎｏｆａｔｒａｎｓｉｔｉｏｎｚｏｎｅｆｒｏｍａｇｒｉｃｕｌｔｕｒａｌｔｏｐａｓｔｏｒａｌｒｅｇｉｏｎｓｏｆｎｏｒｔｈｅｒｎＣｈｉｎａ…     

有机污染源标志物的探讨及其研究意义

在分析广州市饮用水源水及自来水厂沉淀地底泥、市售洗衣粉、洗洁精等样品中有机污染物的基础上,探讨正构烷烃、藿烷、多环芳烃、苯基长链正构烷烃、长链烷基酚等化合物的污染源指示作用,由此探索判别污染源的特征性污染物（污染物标志物）,从而探讨广州市饮用水源水的污染源,这将对于评价水体污染状况、控制污染源排放等具有重要的现实意义。     

An improved method of direct chromosome preparation from chorionic villus and high resolution banding technique

The trophoblast was dissociated from the underlying mesenchymal layer either with acetic acid after short-term prefixation or with mechanical power after fixation twice. The colcemid treatment time was shorted to 16 min and trypsin solution of low pH (6.2) was used for banding. By these steps, the quality of chromosome banding was greatly improved and complete standard chromosome diagnoses were made in 24 of 24 cases. With the modified technique, high resolution banding chromosomes were consistently obtained after short-term incubation.     

乾务水库表层沉积物氮磷和重金属时空分布特征与生态风险评价

为了解乾务水库表层沉积物中的环境质量状况,于2019年丰、枯两季（8月和10月）对库区6个采样点的氮磷营养元素和8项重金属进行了监测,采用综合污染指数法、地累积指数法及潜在生态风险指数法开展生态风险评估和溯源分析。结果表明：乾务水库表层沉积物中TN和TP浓度在丰、枯水期的平均值分别为2 010和433、1 873和308 mg/kg,且总体呈现库中高、南北两端低的时空分布特征。综合污染指数评价结果表明,乾务水库整体TN为重度污染,TP为轻度污染。乾务水库表层沉积物中Hg、As、Cr、Mn、Ni、Cu、Zn和Pb的平均浓度分别为0.22、10.64、30.97、293.25、17.51、21.01、102.65和55.32 mg/kg。时空分布方面,除Mn和Zn外,其他重金属在丰水期污染相对枯水期较重;受水库地形和季节性调水影响,除Mn和Pb外,其他重金属浓度水平在丰水期均表现出库首至库中区域（Q3和Q4采样点）为高值区,库中至库尾区域（Q2和Q3）在枯水期则为高值区。地累积指数法及潜在生态风险指数法评价结果均表明,Hg为主要的生态风险贡献因子,贡献率达75.8 %,库区综合潜在生态风险等级总体为中风险。

     

安徽省冬季采暖耗能对全球气候变暖的响应

基于1971—2018年安徽省77个气象站均一化日平均温度资料,采用趋势分析等方法,研究气候变暖对冬季采暖耗能的影响。结果表明：近48年安徽省冬季显著增暖,采暖初日推迟、终日提前,采暖期长度缩短,采暖强度显著下降。冬季温度在1989年发生突变,此后进入升温通道,因而将研究序列划分为基准时段（1971—1989年）和变暖期（1990—2018年）。相比于基准时段,变暖期内采暖期长度呈现空间一致性缩短,变化幅度自东北向西南递减,皖北北部及江淮之间东部缩短程度最大,大别山及皖南山区为全省低值区。全省采暖强度均减少,减少幅度自北向南递减。采暖节能贡献率介于3.6%~8.9%之间,高值区主要位于皖北北部、江淮之间北部和沿江东部,低值区则位于大别山及皖南两大山区。     

Pollution characteristics of organic and elemental carbon in PM2:5 in Xiamen, China

Xiamen,located on the southeastern coastal line of China,is undergoing rapid urbanization and industrialization,so its air quality has a trend of degradation.However,studies on level,temporal and spatial changes of fine particles (PM2.5) and their carbonaceous fractions are scarce.In this article,abundance,sources,seasonal and spatial variations,distribution of organic carbon (OC) and elemental carbon (EC) in PM2.5,were studied at suburban,urban and industrial sites in Xiamen during four season-representative months in 2009-2010.PM2.5 samples were collected with middle volume sampler and were analyzed for OC and EC with thermal optical transmittance (TOT) method.Results showed that the annual average PM2.5 concentrations were 63.88-74.80 μg/m3 at three sites.While OC and EC concentrations were in the range of 15.81-19.73 μg/m3 and 2.74-3.49 μg/m3,respectively,and clearly presented the summer minima and winter maxima in this study.The carbonaceous aerosol accounted for 42.8％-47.3％ of the mass of PM2.5.The annual average of secondary organic carbon (SOC) concentrations in Xiamen were 9.23-11.36 μg/m3,accounting for approximately 56％ of OC.Strong correlations between OC and EC was found in spring (R2 = 0.50) and autumn (R2 = 0.73),suggesting that there were similar emission and transport processes for carbonaceous aerosols in these two seasons,while weak correlations were found in summer (R2 = 0.33) and winter (R2 = 0.41).The OC/EC ratios in PM2.5 varied from 2.1 to 8.7 with an annual average of 5.7,indicating that vehicle exhaust,coal smoke and biomass burning were main source apportionments of carbonaceous fractions in Xiamen.     

新型反硝化固体碳源释碳性能研究

碳源在生物硝酸盐去除过程中起着重要的提供电子供体的作用,因此是生物反硝化的核心物质之一.选出玉米芯、稻壳、稻草、木屑4种农业废弃物做为反硝化碳源和生物膜载体,研究了4种碳源物质的释碳规律及外界因子对其释碳能力的影响.结果表明,4种碳源材料的释碳过程均满足二级动力学方程;比较而言,稻草的有机物释放量最大,释放速率也最快,...     

重金属离子对不同非水溶性有机物含量土壤胶体上十溴联苯醚迁移行为的影响

为了研究复杂土壤环境中非水溶性有机物和重金属离子对BDE-209（十溴联苯醚）的时空迁移过程和变换规律,在旋转混匀仪[转速为（30±1.0）r/min、温度为（25.0±0.5）℃]内避光试验条件下,分析V_水:m_土为5、pH为6.8±0.1条件下,森林土壤和农田土壤中非水溶性有机物含量（分别为2.2%和4.7%）和重金属离子（Fe3+、Cu2+、Zn2+）含量对土壤中BDE-209环境迁移行为的影响.结果表明:重金属离子在森林土和农田土土壤胶体上的平衡时间和平衡含量分别为40、32 h和（49.4±1.2）（81.7±1.9）mg/g.重金属离子对森林土（重金属负荷为0~60 mg/g）和农田土（重金属负荷为0~80 mg/g）土壤胶体混凝沉降强弱作用均依次为Fe3+最强,其次为Cu2+、Zn2+;而当森林土重金属负荷为60~100 mg/g、农田土重金属负荷为80~100 mg/g时,森林土和农田土土壤胶体质量浓度分别稳定在（49.3±1.3）和（50.4±1.1）mg/L,致使上清液中ρ（BDE-209）由（388.5±13.2）ng/L分别降至（24.7±21.7）和（25.4±18.8）ng/L.此外,重金属离子未实现BDE-209由土壤胶体向重金属胶体的再分配过程[上清液中ρ（BDE-209）与土壤胶体质量浓度比值保持在（493.1±6.8）ng/g],仅通过改变土壤胶体环境行为来影响BDE-209迁移过程,进而导致土壤环境中BDE-209时空迁移过程与土壤胶体迁移行为一致.      

三峡水库蓄水后不同水位期干流氮、磷时空分异特征

研究三峡水库蓄水前后营养盐的变化,对于探讨水库运行对其的影响并提出合理的管理建议具有重要意义.依据2008年3月～2009年2月对长江干流三峡区段朱沱、寸滩、扇沱、清溪场、晒网坝、培石,共6个断面和其中1个垂直断面逐月水文、水质监测,按照三峡水库运行的水位特点,将数据样本分成高水位(10～2月)和低水位(3～9月)2个...