无机矿质颗粒悬浮物对富营养化水体氨氮的吸附特性

利用蒙脱土、高岭土和太湖沉积物矿质组分3种材料,模拟研究了水体悬浮矿质颗粒物对富营养化水体中氨氮的吸附特性.实验表明,30min内3种材料对氨氮的吸附基本可达到平衡;等温平衡吸附均符合Henry吸附模式,在无机矿质颗粒悬浮物浓度1000mg/L,初始氨氮浓度1.0mg/L,pH=7.00实验条件下,吸附分配系数分别依次为548.30,287.36,191.27L/kg.相同实验条件下,随着pH、盐度和温度的增大或升高,矿质颗粒对氨氮的平衡吸附量均有不同程度的减小趋势,pH的影响较显著.随着悬浮颗粒物浓度在1000mg/L以下范围增大,固相氨氮平衡吸附量显著减小.     

自制ZSM-5分子筛对甲苯气体的吸附-脱附性能

考察了自制ZSM-5分子筛对甲苯气体的吸附-脱附性能,并与市售MCM-22分子筛进行了对比实验。实验结果表明:在吸附温度为25℃、进口甲苯质量浓度为840mg/m3、吸附气体流速为0.016m/s、床层高度为15cm的条件下,出口甲苯质量浓度达到0.8mg/m3时的穿透时间为82min,吸附效率为4.26mg/g;在脱附温度为80℃、脱附气体流速为0.016m/s的条件下,脱附35min时出口甲苯质量浓度达到最大,为1220mg/m3。自制ZSM-5分子筛的吸附-脱附性能优于市售MCM-22分子筛。     

Migration of manganese and iron during the adsorption-regeneration cycles for arsenic removal

Fe-Mn binary oxide incorporated into porous diatomite (FMBO-diatomite) was prepared in situ and regenerated in a fixed-bed column for arsenite [As(III)] and arsenate [As(V)] removal. Four consecutive adsorption cycles were operated under the following conditions: Initial arsenic concentration of 0.1 mg·L^-1, empty bed contact time of 5 min, and pH 7.0. About 3000, 3300, 3800, and 4500 bed volumes of eligible effluent (arsenic concentration≤0.01 mg·L^-1) were obtained in four As(III) adsorption cycles; while about 2000, 2300, 2500, and 3100 bed volumes of eligible effluent were obtained in four As(V) adsorption cycles. The dissection results of FMBO-diatomite fixed-bed exhibited that small amounts of manganese and iron were transferred from the top of the fixed-bed to the bottom of the fixed-bed during As(III) removal process. Compared to the extremely low concentration of iron (<0.01 mg·L^-1), the fluctuation concentration of Mn²⁺ in effluent of the As(III) removal column was in a range of 0.01–0.08 mg·L^-1. The release of manganese suggested that manganese oxides played an important role in As(III) oxidation. Determined with the US EPA toxicity characteristic leaching procedure (TCLP), the leaching risk of As(III) on exhausted FMBO-diatomite was lower than that of As(V).     

P204-煤油萃取剂的生物降解性

采用测定溶剂饱和溶液 BOD₅和 COD的方法对混合溶剂 P204(二-(2-乙基己基 )磷酸 )-煤油的生物降解性进行了研究 .结果表明 ,不同浓度的 P204(煤油)均可降解 .当溶剂中 P204的浓度小于 70%时 ,平衡水相的 COD及 BOD₅ 与初始溶剂中P204对煤油的体积比成正比 ;当 P204的浓度大于 70%时 ,平衡水相的 COD及 BOD₅基本保持不变 .同时 ,建立了 P204(煤油)平衡水相中 P204的浓度的表达式 ,对研究混合溶剂的生物降解性具有一定的指导意义 .     

硝化细菌富集技术分析及方法研究

在分析硝化细菌特性的基础上,研究探讨了利用提高基质浓度来富集硝化细菌的可行性,并比较了不同培养方式及富集前后活性污泥中硝化细菌的浓度。试验结果表明,当温度为30℃、pH=6.5～8.0、DO>2mg/L时,经过12～13周的富集培养,污泥中硝化菌浓度可达2.0×18~8(MPN)/g(MLSS),是未经富集污泥中硝化菌浓度的12.5～20倍。     

类脂/醋酸纤维素复合吸附材料的制备与性能

采用相转化法将类脂包埋到醋酸纤维素(CA)中,制备出了具有对水中低剂量亲脂性有机污染物高效吸附去除的平板膜.以扫描电子显微镜观察了复合材料的结构形貌和表面特征.利用机械搅拌方式和超声方式对类脂进行分散的实验表明,超声对类脂的均匀分散具有强化作用.同时考察了铸膜温度(室温、0℃)对类脂分散的效果,表明低温有助于形成小的脂滴.另外,通过复合膜的红外谱图证实,类脂和CA属于物理混合,不会改变类脂的分子结构,从而不会影响类脂对亲脂性有机污染物的吸附性能.通过荧光分析法分析复合膜在正己烷溶剂中的稳定情况,表明类脂已被完好地包埋到膜中,因而在去除有机污染物的过程中不会从复合膜中渗出.     

Purification function of the natural wetland in the Liaohe Delta

１ＩｎｔｒｏｄｕｃｔｉｏｎＳｔｒｕｃｔｕｒｅ，ｆｕｎｃｔｉｏｎａｎｄｃｈａｎｇｅａｒｅｔｈｒｅｅｉｍｐｏｒｔａｎｔａｓｐｅｃｔｓｏｆｌａｎｄｓｃａｐｅｅｃｏｌｏｇｙ（Ｆｏｒｍａｎ，１９８６）．Ｌａｎｄｓｃａｐｅｆｕｎｃｔｉｏｎｍｅａｎｓｔｈｅｉｎｔｅ...     

Characteristics and formation mechanism of regional haze episodes in the Pearl River Delta of China

To investigate the characteristics and the specific mechanism of continuous haze,comprehensive measurements were conducted from 15 October to 19 November in the Atmospheric Environment Monitoring Super-Station in Heshan of Guangdong province.Five haze episodes occurred in October and November 2014 in the Pearl River Delta(PRD)region. The meteorological parameters, gas data, chemical compositions, and optical parameters of the aerosols were obtained. Among these events, the second haze episode,with the highest concentration of PM2.5 of 187.51 μg/m~3, was the most severe. NO~3-was always higher than SO_4~(2-), which indicated that motor vehicles played an important role in the haze, even though the oxidation rate from SO_2 to SO_4~(2-)was faster than that of NOXto NO_3~-. The difference between the hourly averages of Na+and K+during the haze episode and clean days was small, implying that straw combustion and sea salt had no significant effect on the occurrence of haze, and the backward trajectories of the air masses also conformed with this result. The air pollutants were difficult to disperse because of the significant decrease in the planetary boundary layer(PBL) height. Relative humidity played a crucial role in the formation of haze by leading to hygroscopic growth of the diameter of aerosols.     

Treatment of coking wastewater by a novel electric assisted micro-electrolysis filter

A newly designed electric assisted micro-electrolysis filter(E-ME) was developed to investigate its degradation efficiency for coking wastewater and correlated characteristics. The performance of the E-ME system was compared with separate electrolysis(SE) and micro-electrolysis(ME) systems. The results showed a prominent synergistic effect on COD removal in E-ME systems. Gas chromatography/mass spectrometry(GC–MS) analysis confirmed that the applied electric field enhanced the degradation of phenolic compounds.Meanwhile, more biodegradable oxygen-bearing compounds were detected. SEM images of granular activated carbon(GAC) showed that inactivation and blocking were inhibited during the E-ME process. The effects of applied voltage and initial p H in E-ME systems were also studied. The best voltage value was 1 V, but synergistic effects existed even with lower applied voltage. E-ME systems exhibited some p H buffering capacity and attained the best efficiency in neutral media, which means that there is no need to adjust p H prior to or during the treatment process. Therefore, E-ME systems were confirmed as a promising technology for treatment of coking wastewater and other refractory wastewater.     

The effects of hydrogen peroxide pre-oxidation on ultrafiltration membrane biofouling alleviation in drinking water treatment

Pre-oxidation is widely used to reduce ultrafiltration membrane fouling.However,the variation in the composition of microbial communities and extracellular polymeric substances(EPSs) accompanying pre-oxidation in drinking water treatment has received little attention.In this study,hydrogen peroxide(H_2O_2) was used in a coagulationultrafiltration process with Al_2(SO_4)_3·18H_2O.A long-term reactor experiment(60 d) showed that pre-oxidation alleviated membrane fouling,mainly due to its inhibition of microbial growth,as observed by flow cytometry measurements of the membrane tank water.Further analysis of the formed cake layer demonstrated that the corresponding levels of EPS released from the microbes were lower with than without H_2O_2 treatment.In comparison to polysaccharides,proteins dominated the EPS.2 D-electrophoresis showed little difference(p 0.05,Student's t-test) in the composition of proteins in the cake layer between the treatments with and without H_2O_2.The molecular weights of proteins ranged from approximately 30–50 kDa and the majority of isoelectric points ranged from 6 to 8.Highthroughput sequencing showed that the predominant bacteria were Proteobacteria,Bacteroidetes,and Verrucomicrobia in both cake layers.However,the relative abundance of Planctomycetes was higher in the cake layer with H_2O_2 pre-oxidation,which was likely probably due to the strong oxidative resistance of its cell wall.Overall,our findings clarify the fundamental molecular mechanism in H_2O_2 pre-oxidation for ultrafiltration membrane bio-fouling alleviation in drinking water treatment.