Investigation on Fe, Mn, Zn, Cu, Pb and Cd fractions in the natural surface coating samples and surficial sediments in the Songhua River, China

Natural surface coating samples （NSCSs） from the surface of shingles and surficial sediments （SSs） in the Songhua River, China were employed to investigate the relationship between NSCSs and SSs in fractions of heavy metals （Fe, Mn, Zn, Cu, Pb, and Cd） using the modified sequential extraction procedure （MSEP）. The results show that the differences between NSCSs and SSs in Fe fi＇actions were insignificant and Fe was dominantly present as residual phase （76.22% for NSCSs and 80.88% for SSs） and Fe-oxides phase （20.33% for NSCSs and 16.15% for SSs）. Significant variation of Mn distribution patterns between NSCSs and SSs was observed with Mn in NSCSs mainly present in Mn-oxides phase （48.27%） and that in SSs present as residual phase （45.44%）. Zn, Cu, Pb and Cd were found dominantly in residual fractions （〉48%）, and next in solid oxides/hydroxides for Zn, Pb and Cd and in easily oxidizable solids/compounds form for Cu, respectively. The heavy metal distribution patterns implied that Fe/Mn oxides both in NSCSs and SSs were more important sinks for binding and adsorption of Zn, Pb and Cd than organic matter （OM）, and inversely, higher affinity of Cu to OM than Fe/Mn oxides in NSCSs and SSs was obtained. Meanwhile, it was found that the distributions of heavy metals in NSCSs and SSs were similar to each other and the pseudo-total concentrations of Zn, Cu, Pb and Cd in NSCSs were greater than those in SSs, highlighting the more importance for NSCSs than SSs in controlling behaviours of heavy metals in aquatic environments.     

厌氧酸化-二级PSB流化床工艺处理高浓度有机废水

采用厌氧酸化+二级光合细菌(PSB)流化床的组合工艺对植物压榨发酵废水进行降解实验,一级流化床(PSB1)中填料为轻质多孔炭渣,二级流化床(PSB2)为活性炭,扰动方式分别采用机械流化和机械气动组合流化,稳定运行40d。结果表明,进水酸化12h后CODCr由80000~120000mg/L降至63000~95000mg/L,进而由系统出水回流稀释至8000~12000mg/L,进入二级流化床反应器,PSB1白天厌氧光照、夜间微好氧,PSB2白天微好氧、夜间好氧,停留48h,CODCr降至295.8~384mg/L,稳定实现96.2%以上的CODCr去除率,TN去除率为71.3%。     

西安市夏季大气中生物二次有机气溶胶的分子组成与粒径分布

2011年夏季8月,在西安交通大学主楼顶（距离地面约100 m）运用MOUDI采样器采集了5套不同粒径大气气溶胶样品,经TMS硅烷化后运用GC/MS定量分析了生物二次有机气溶胶（BSOA）异戊二烯氧化产物（2-甲基丁四醇, C₅-烯三醇和2-甲基甘油酸）、单蒎烯类氧化产物（顺蒎酸,蒎酮酸,3-羟基戊二酸和3-甲基-1,2,3-丁三酸）以及倍半萜烯氧化产物（倍半萜烯酸）浓度。结果显示：西安城区大气BSOA中主要以异戊二烯类为主,其次是单萜烯和倍半萜烯类BSOA,其氧化所产生的生物二次有机碳（BSOC）浓度分别为0.39 μgC·m^-3,0.13 μgC·m^-3和0.10 μgC·m^-3。粒径分布研究表明：BSOA主要富集在细颗粒物上。MBTCA/CPA特征比值表明：采样期间西安城区BSOA主要来自本地源,老化程度较低。     

工业废水对洹河有机污染的调查与分析

采用适当的样品前处理技术,利用GC/MS对洹河水及焦化厂、染料厂废水进行有机污染物的分析,确定了工业废水对洹河造成有机污染的主要化合物,从而为企业污水的处理和洹河治理提供依据.     

水性涂料“大军压境”

<正>十年前,水性涂料还只是一个新兴的名词,可是十年之后的今天,水性涂料已经深入我们的生活。面对水性涂料的大军压境,你准备好了么?水性涂料在中国的发展经历了10余年历程。     

磁絮凝法处理DZA有机废水的研究

本文介绍了磁絮新颖产分离技术,应用该技术能有效处理水中ＤＺＡ有机物,实现数秒内的快速分离污泥,污泥含水率低。     

雷州半岛红树林表层沉积物正构烷烃组成分布特征研究

本文研究了雷州半岛高桥镇、特呈岛、湖光镇和金沙湾4个区域红树林表层沉积物中正构烷烃的含量、组成分布及来源特征。结果表明,研究区域红树林表层沉积物中总有机碳(TOC)含量为0.10%～5.62%,正构烷烃总含量(∑n-Alk)为0.69～16.60μg/g(dw)。红树林表层沉积物中正构烷烃组成以中长链(n-C₂₃～n-C₃₁)为主,呈单峰型分布。除金沙湾以外,其他区域红树林表层沉积物中正构烷烃组成奇偶优势明显。正构烷烃组成分布及平均链长(ACL)、碳优势指数(CPI)、短链/长链比值(∑n-C₂₀^-/∑n-C₂₁⁺)、陆海来源比值(TAR)、水生植物贡献比值(P_aq)等指标的主成分分析(PCA)结果显示,研究区域红树林表层沉积物中正构烷烃主要来源于高等植物,其中,高桥镇红树林表层沉积物中正构烷烃主要来源于陆源高等植物,而部分湖光镇、特呈岛红树林表层沉积物中正构烷烃的水生植物来源贡献较大,金沙湾红树林表层沉积物中正构烷烃可能受人类活动的...     

2018~2021年成都市碳质气溶胶变化特征分析

碳质气溶胶是细颗粒物（PM_2.5）的重要组成部分,可影响全球气候变化、大气能见度、区域空气质量和人类健康. 为了探究减排背景下碳质气溶胶的长期变化特征,通过实时在线监测获取了2018～2021年成都市PM_2.5样品中的有机碳（OC）、元素碳（EC）、挥发性有机物（VOCs）浓度以及相应的气象数据. 结果表明,监测期间ρ（OC）和ρ（EC）均值分别为（10.9 ±5.7）μg·m^-3和（2.6 ±1.9）μg·m^-3,在PM_2.5中占比分别为25.2%和6.0%,ρ（SOC）均值为（5.7 ±3.3）μg·m^-3,在OC中的占比为52.9%. OC和EC浓度随PM_2.5年际变化趋势一致,2018~2020年呈下降趋势[PM_2.5：年均下降浓度为-7.1 μg·（m³·a）^-1,年均降幅为-14.6 %·a^-1;OC：年均下降浓度为-1.7 μg·（m³·a）^-1,年均降幅为-14.2 %·a^-1;EC：年均下降浓度为-0.1 μg·（m³·a）^-1,年均降幅为-4.4 %·a^-1],2021年各污染物浓度较2020年均有不同幅度反弹. PM_2.5和OC浓度大小为：冬>春>秋>夏,EC浓度大小为：冬>秋>春>夏,OC和EC占比分别呈夏季和秋季高于其他季节,对应季节OC和EC占比分别为26.8%和6.9%. 随着污染程度的加重,OC、EC和SOC浓度逐步上升,但在PM_2.5中的占比却呈下降趋势,说明成都市PM_2.5污染的控制因子并不是碳组分. 源解析结果表明,成都市碳质气溶胶主要受机动车、工业源、生物质燃烧源、VOCs二次转化影响. 2019~2021年,EC受VOCs中机动车特征组分影响逐年下降,春季和秋季OC和EC受VOCs影响大于其他季节,春秋季节应加大VOCs排放治理,减少二次转化影响.     

Organic matter and concentrated nitrogen removal by shortcut nitrification and denitrification from mature municipal landfill leachate

An UASB＋Anoxic/Oxic （A/O） system was introduced to treat a mature landfill leachate with low carbon-to-nitrogen ratio and high ammonia concentration. To make the best use of the biodegradable COD in the leaehate, the denitrifieation of NOx^--N in the reeireulation effluent from the elarifier was carried out in the UASB. The results showed that most biodegradable organic matters were removed by the denitrifieation in the UASB. The NH4^＋-N loading rate （ALR） of A/O reactor and operational temperature was 0.28- 0.60 kg NH4^＋-N/（m^3-d） and 17-29℃ during experimental period, respectively. The short-cut nitrification with nitrite accumulation efficiency of 90%-99% was stabilized during the whole experiment. The NH4^＋-N removal efficiency varied between 90% and 100%. When ALR was less than 0.45 kg NH4^＋-N/（m^3.d）, the NH4^＋-N removal efficiency was more than 98%. With the influent NH4^＋-N of 1200-1800 mg/L, the effluent NH4^＋-N was less than 15 mg/L. The shortcut nitrification and denitrifieation can save 40% carbon source, with a highly efficient denitrifieation taking place in the UASB. When the ratio of the feed COD to feed NH4^＋-N was only 2-3, the total inorganic nitrogen （TIN） removal efficiency attained 67%-80%. Besides, the sludge samples from A/O reactor were analyzed using FISH. The FISH analysis revealed that ammonia oxidation bacteria （AOB） accounted for 4% of the total eubaeterial population, whereas nitrite oxidation bacteria （NOB） accounted only for 0.2% of the total eubaeterial population.