Strength characteristics of geosynthetic reinforced mechanically biologically treated waste by triaxial test

Environmental Science and Pollution Research - The reinforcement strength characteristics of mechanically biologically treated (MBT) waste were studied by conducting consolidated undrained triaxial...     

三峡水库蓄水后荆江三口分流量计算方法

荆江三口河道(藕池河、虎渡河、松滋河)的水沙变化是江湖关系演变的重要内容,其分水分沙变化驱动江湖关系的调整,而且三峡水库蓄水后加剧了三口分流显著减少.通过三口河道的5个水文站2003～2018年水位与流量实测数据分析,考虑口门区水位下降等因素,得到三口河道分流量的经验公式,并量化荆江枯水位下降对三口河道分流量的影响.结果表明:三口分流量是口门区水位的函数,口门区水位下降引起三口河道分流量的同向减少.根据水位与流量关系得到三口五站简化分流量计算公式,进一步考虑口门区水位下降、河道宽度等因素,得到经验分流量与修正分流量的计算公式.采用2017～2018年实测日平均水位值与流量值,验证藕池河管家铺站与康家岗站的分流量经验公式,得到相对误差分别为4.5％与13.7％,验证虎渡河弥陀寺站的相对误差为11.5％,松滋河新江口与沙道观的相对误差值分别为4.5％与7.3％.可知荆江三口分流量的经验公式与实测值符合良好,可作为评估未来受荆江干流水位下降对荆江三口河道分流量的影响.     

Summer time haze characteristics of the urban atmosphere of Gwangju and the rural atmosphere of Anmyon, Korea

An extensive visibility monitoring was carried out simultaneously in the urban area of Gwangju and the rural area of Anmyon, Korea. This study examines patterns of visibility impairment and haze-forming pollutant concentrations on both sites resulting from natural and anthropogenic sources of gases and particles. Optical visibility measurements by a transmissometer, a nephelometer and an aethalometer provide aerosol light extinction, scattering, and absorption coefficients for both sites. In order to investigate the physico-chemical characteristics of atmospheric aerosols, aerosol samples were collected by various aerosol samplers at GJVMS (Gwangju Visibility Monitoring Station) and at KGAWO (Korea Global Atmosphere Watch Observatory), respectively. In addition, haze characteristics causing visibility impairment at those two sites were analyzed to obtain source contributions by regionally transported aerosols using grid analysis and display system (GrADS) from NECP reanalysis data. During the intensive monitoring period, ammonium sulfate was dominantly responsible for the fine particle mass loading at GJVMS, whereas organic carbon was the largest contributor at KGAWO. Light scattering by particles accounted for 52.8 to 81.3% of the range at the urban site, GJVMS and for 72.1 to 94.2% of the range at the rural site, KGAWO. Light absorption by the EC and NO₂ was between 14.5 and 34.8% at GJVMS, which was higher than the observed 1.1 ∼ 6.8% at KGAWO, respectively. Light scattering by aerosol was higher in the rural area than in the urban area. And organic carbon concentration was observed to be significantly higher than the concentration of elemental carbon at KGAWO. These haze-forming carbonaceous particles originate from anthropogenic pollutants at the urban atmosphere but they can be produced by natural environments such as marine and forest at the rural atmosphere.     

Comparisons of polybrominated diphenyl ethers levels in paired South Korean cord blood, maternal blood, and breast milk samples

Polybrominated diphenyl ethers (PBDEs), commonly used flame retardants, have been reported as potential endocrine disruptor and neurodevelopmental toxicants, thus giving rise to the public health concern. The goal of this study was to investigate the relationship between umbilical cord blood, maternal blood, and breast milk concentrations of PBDEs in South Korean. We assessed PBDE levels in paired samples of umbilical cord blood, maternal blood, and breast milk. The levels of seven PBDE congeners were measured in 21 paired samples collected from the Cheil Woman’s Hospital (Seoul, Korea) in 2008. We also measured thyroid hormones levels in maternal and cord blood to assess the association between PBDEs exposure and thyroid hormone levels. However, there was no correlation between serum thyroxin (T4) and total PBDEs concentrations. The total PBDEs concentrations in the umbilical cord blood, maternal blood, and breast milk were 10.7 ± 5.1 ng g⁻¹ lipid, 7.7 ± 4.2 ng g⁻¹ lipid, and 3.0 ± 1.8 ng g⁻¹ lipid, respectively. The ranges of total PBDE concentrations observed were 2.28-30.94 ng g⁻¹ lipid in umbilical cord blood, 1.8-17.66 ng g⁻¹ lipid in maternal blood, and 1.08-8.66 ng g⁻¹ lipid in breast milk. BDE-47 (45-73% of total PBDEs) was observed to be present dominantly in all samples, followed by BDE-153. A strong correlation was found for major BDE-congeners between breast milk and cord blood or maternal blood and cord blood samples. The measurement of PBDEs concentrations in maternal blood or breast milk may help to determine the concentration of PBDEs in infant.     

Detecting points as developmental delay based on the life-history development and urosome deformity of the harpacticoid copepod, Tigriopus japonicus sensu lato, following exposure to benzo(a)pyrene

To identify ecotoxicological responses to an endocrine disrupter, benzo(a)pyrene, we examined the life-history of the harpacticoid copepod, Tigriopus japonicus sensu lato. Based on the life-history of copepods, survival rate of nauplii (NSR) and copepodites (CSR), copepodite emergence day (CED) and adult male emergence day (AMED), sex ratio (MER), brooding success rate (BSR), and first brooding day of adult females (FBD) were measured. Significant differences were observed in the survival and development of nauplii (NSR and CED) and sex ratio (MER) of exposed and non-exposed copepods. Moreover, high concentration of BaP can be lethal to copepodite and exhibited a delay of growth. In this study, the CED and AMED among ecotoxicological response based on life-history developments were delayed and the body characteristics decreased in response to exposure to benzo(a)pyrene. The dwarfism and urosome deformity of the T. japonicus s.l. was exhibited in response to chemical exposure. Specifically, the body characteristics and biomass of dwarf copepods that had been exposed to benzo(a)pyrene were 30% and 50% lower than the control group, respectively. The incidence of abnormal urosomes was divided into two types. The first deformity type was signs of shrinkage in the middle of the urosome or the entire urosome was narrower than those of the control organisms. In the second type, the anal somite and the distal side of the urosome had abnormally swelled. Taken together, the nauplii and copepodid development of T. japonicus s.l. can be used as a useful biomaker for detecting developmental delay based on their entire life-history. In addition, the urosome deformity was used a good potential monitoring tool invading various chemicals and environmental contamination into water system.     

膜生物反应器工艺污水处理厂设计进水水质的确定

城市污水处理厂进水水质是工程设计的基本参数,进水水质的测定分析对污水处理厂的设计具有重要意义。对无锡市城北污水处理厂的现状进水水质进行了调查和分析,提出按照水质指标浓度出现的频率确定污水处理厂设计进水水质的方法,并针对采用的膜生物反应器(MBR)工艺的特点,提出:(1)根据实测数据按照一定的保证概率可以用来确定城市污水处理厂设计进水水质;(2)为了使水质的确定更加符合设计工程的实际情况,根据实测数据分析确定设计进水水质指标时,一般还需要进行趋势性调整和季节性调整;(3)确定合理的指标浓度与流量,以此为依据进行反应池的工艺设计,同时要校核夏季温度高、浓度低、流量大和冬季温度低、浓度高、流量小的工况是否满足处理要求,然后取冬、夏季校核值以及未作季节性调整设计值中最不利情况作为设计值,才能充分保证出水达到处理要求。     

华北与闽粤沿海及银川地震区(带)地震周期的划分与研究

按地震在空间上的相似活动过程排列的华北与闽粤沿海及银川地震区 (带 )地震活动周期表 ,以华北地震活动为主线 ,将公元前 2 80年咸阳 5 级地震至 1 988年 2月 2 5日彰武 4 8级地震间 2 2 6 7年的华北地震活动划分为 4个时间层次。其组合关系是 ,一个超长地震周期由初、前、主、余震期 4个地震期组成 ;除前震期只有一个地震周期外 ,初、主、余震期都包含前弱后强两个地震周期 ;每个地震周期多分为初、前、主、余震段 4个地震段。闽粤沿海地震区和银川地震带的主震段分别与华北初、余震段同期活动。地震周期是介于前人划分的地震幕与地震活动期之间一个新的更为重要的时间层次。华北 7个地震周期的起止时间是 :-2 80 .5 0～ 8.2 2～ 880 .1 2～ 1 337.6 9～ 1 5 6 8.37～ 1 730 .75～ 1 85 5 .95～ 1 988.1 5年。并从时空强 3方面阐述了华北地震周期性活动规律 ,分析了 3个地震区、带地震周期的相互关系。华北地震周期可作为标准地震周期与不同地区地震周期相对比 ,具有重要的预报意义