制药废水有机污染物特性分析与处理

分析了某制药企业废水生物处理站进出水中有机污染物的相对分子质量分布和气相色谱—质谱图谱,提出了根据废水水质特性有针对性地确定制药废水处理工艺的新思路.实验结果表明:进出水中的有机污染物主要是相对分子质量小于1 000的物质,且主要来源于车间5排放的COD比重大、水量小的工段废水;采用旋转蒸馏预处理法处理车间5废水,可使...     

Enhanced arsenate removal from aqueous solution by Mn-doped MgAl-layered double hydroxides

Environmental Science and Pollution Research - In this study, Mn-doped MgAl-layered double hydroxides (LDHs) were successfully synthesized for efficient removal arsenate from aqueous solution. The...     

Preparation and Properties of a Chitosan–Hyaluronic Acid-Polypyrrole Conductive Hydrogel Catalyzed by Laccase

Electro conductive hydrogels, consisting of chitosan (CS), hyaluronic acid (HA), and polypyrrole (PPy), were prepared via an in situ enzymic polymerization of pyrrole in the CS–HA hydrogel, using laccase as the catalyst. This CS–HA–PPy composite hydrogel showed good conductivity. The chemical structure and morphology of this conductive hydrogel were studied by Fourier transform infrared spectroscopy, scanning electron microscopy, and X-ray diffraction technique. For CS–HA–PPy and CH–HA hydrogel, the temperature at which fastest decomposition occurred was 260 and 244 °C, respectively. That means the thermal stability of CS–HA–PPy is better than CS–HA hydrogel. The conductive hydrogel also showed excellent swelling and deswelling behaviors.     

Continuous measurement of peroxyacetyl nitrate (PAN) in suburban and remote areas of western China

Knowledge on atmospheric abundance of peroxyacetyl nitrate (PAN) is important in assessing the severity of photochemical pollution, and for understanding chemical transformation of reactive odd nitrogen and its impact on the budget of tropospheric ozone (O₃). In summer 2006, continuous measurements of PAN were made using an automatic GC–ECD analyzer with an on-line calibrator at a suburban site of Lanzhou (LZ) and a remote site of Mt. Waliguan (WLG) in western China, with concurrent measurements of O₃, total reactive nitrogen (NO_y) and carbon monoxide (CO). At LZ, several photochemical episodes were observed during the study, and the average mixing ratio of PAN (plus or minus standard deviation) was 0.76 (±0.89) ppbv with the maximum value of 9.13 ppbv, compared to an average value of 0.44 (±0.16) ppbv at remote WLG. The PAN mixing ratios in LZ exhibited strong diurnal variations with a maximum at noon, while enhanced concentrations of PAN were observed in the evening and a minimum in the afternoon at WLG. The daily O₃ and PAN concentration maxima showed a strong correlation (r² = 0.91) in LZ, with a regression slope (PAN/O₃) of 0.091 ppbv ppbv^?1. At WLG, six well-identified pollution plumes (lasting 2–8 h) were observed with elevated concentrations of PAN (and other trace gases), and analysis of backward particle release simulation shows that the high-PAN events at WLG were mostly associated with the transport of air masses that had passed over LZ.     

Single particle mass spectrometry of oxalic acid in ambient aerosols in Shanghai: Mixing state and formation mechanism

Oxalic acid in individual aerosol particles was measured using single particle aerosol time-of-flight mass spectrometry (ATOFMS) in the summer of 2007 in Shanghai, China. Oxalate was found in 3.4% of total particles with diameters in the range of 0.2 – 2.0 μm. Size, chemical composition and hourly temporal counts of single particles that contained oxalic acid were measured. The predominant types of oxalate-containing particles were characterized to distinguish the primary and secondary sources of oxalic acid. Biomass burning was revealed as a major primary source of oxalic acid which contributed more than 20% of the oxalate-containing particles. Evidences for two different formation pathways of oxalic acid were observed in our experiment. The number fraction of oxalate-containing particles correlated with that of sulfate particles and the changes of air parcel backward trajectories, suggesting that in-cloud processing played important roles in oxalic acid formation. The diurnal patterns of dust and sea salt particle counts fitted well with the ambient relative humidity variation, suggesting that heterogeneous reactions occurring in hydrated/deliquesced aerosols also contributed to the production of oxalic acid.     

基于生态安全的DAT-IAT城市污水处理工艺改进研究

通过正交试验,得到了DAT-IAT工艺和A/DAT-IAT工艺处理城市污水的常规指标去除和生态毒理指标削减的最优运行条件。结果表明,在正交试验的同一工艺中,COD去除最优运行条件的出水COD值优于生态毒性削减最优运行条件的出水COD值,但前者出水的生态毒性较大。由于厌氧池的水解酸化作用,A/DAT-IAT工艺对COD和生态毒性的处理效果均优于DAT-IAT工艺,并且回流总能耗低于DAT-IAT工艺,但是出水COD仍不达标。为了降低进入工艺的COD的总量,以絮凝沉淀做为预处理工艺,并采用Al残留量最小的絮凝剂投药量以降低出水中残留Al带来的生态风险。结果表明,在COD去除最优运行条件下,具有絮凝预处理的工艺对COD的去除效果优于没有絮凝预处理的工艺。絮凝-A/DAT-IAT工艺在COD去除最优运行条件下出水COD为104.46 mg/L,满足排放标准。在毒性削减最优运行条件下,具有絮凝预处理的工艺的出水生态毒性有所上升,但是污染物的总量得到了大幅削减。絮凝-A/DAT-IAT工艺与DAT-IAT工艺相比,在污染物去除效率得到大幅增加的同时,生态毒性得到有效控制,生态安全得到了有效的保障。     

培养藻类制取生物能源的研究

能源紧张和环境污染是全世界所面临的共同问题,用藻类替代传统作物生产生物能源是生物质能的重要发展方向之一。文章介绍了国内外对藻类培养条件、光生物反应器型式、藻类基因工程、藻细胞收集方法以及能源藻类生产系统的研究成果。研究认为,以藻类为原料生产生物燃料具有良好的发展前景,并指出了今后能源藻类生长的重点研究方向。     

热化学洗涤－超声波分离技术处理油田含油污泥

为解决大量堆存的含油污泥所造成的环保隐患问题,长庆油田建设了含油污泥处理站。采用"热化学洗涤-超声波分离"工艺对含油污泥进行处理。含油污泥的含油率从处理前的48.9%降到处理后2.0%,除油率达到95.9%,除油效果较好。     

基于GIS的松花江干流暴雨洪涝灾害风险评估

以黑龙江省内的松花江干流流域作为研究区,从现代灾害风险理论出发,综合运用GIS空间分析和灾害风险评估数学方法,对松花江干流流域的暴雨洪涝灾害风险进行了定量评价.研究利用遥感数据和社会经济数据,在空间分析基础上,通过对暴雨洪涝灾害的危险性、承灾体的暴露性、脆弱性以及区域防灾减灾能力的分析,确定影响各个县市暴雨洪涝灾害风险的具体方面.并将因子集成为洪涝灾害风险指数(FDRI),在此基础之上绘制出松花江干流流域的洪涝灾害风险区划图,结果表明松花江干流洪涝灾害风险以哈尔滨和佳木斯两市最大,上游洪涝灾害风险大于下游.     

Degradation of pentachlorobiphenyl by a sequential treatment using Pd coated iron and an aerobic bacterium (H1)

The reductive dechlorination and biodegradation of 2,2^′4,5,5^′-pentachlorobiphenyl (PCB#101) was investigated in a laboratory-scale. Palladium coated iron (Pd/Fe) was used as a catalytic reductant for the chemical degradation of 2,2^′4,5,5^′-pentachlorobiphenyl, and an aerobic bacteria was used for biodegradation following the chemical reaction in this study. Dechlorination was affected by several factors such as Pd loading, initial soil pH and the amount of Pd/Fe used. The results showed that higher Pd loading, higher dosage of Pd/Fe and slightly acid condition were beneficial to the catalytic dechlorination of 2,2^′,4,5,5^′-pentachlorobiphenyl. In laboratory batch experiments, 2,2^′4,5,5^′-pentachlorobiphenyl was reduced in the presence of Pd/Fe bimetal, which was not further degraded by aerobic bacteria. 2,2^′,4-trichlorobiphenyl (PCB#17), a reduction product from 2,2^′4,5,5^′-pentachlorobiphenyl, was readily biodegraded in the presence of a aerobic bacterial strain. It is suggested that an integrated Pd/Fe catalytic reduction-aerobic biodegradation process may be a feasible option for treating PCB-contaminated soil.