Determination of vanillin in vanilla perfumes and air by capillary electrophoresis

The present study investigated capillary electrophoretic detection of vanillin in vanilla perfume and air. An UV-absorbance detector was used in a home-made capillary electrophoretic instrument. A fused silica capillary (outer diameter: 364μm, inner diameter: 50 m) was used as a separation capillary, and a high electric voltage (20 kV) was applied across the two ends of the capillary. Total length of the capillary was 70 cm, and the effective length was 55 cm. Experimental results showed that the vanillin peak was detected at about 600, 450, and 500 seconds when pH of running buffers in CE were 7.2, 9.3, and 11.5, respectively. The peak area of vanillin was proportional to its concentration in the range of 0-10^-2 mol/L. The detection limit was about 10^-5 mol/L. Vanillin concentration in a 1% vanilla perfume sample was determined to be about 3×10^-4 mol/L, agreed well with that obtained by a HPLC method. Furthermore, determination of vanillin in air by combination of CE and active carbon adsorption method was investigated.     

韶钢水泥厂的粉尘污染及综合防治措施

韶钢水泥厂在进行干法生产时,会产生大量的粉尘,严重影响生产和厂区周围居民的正常生活,危害严重。通过一些综合防治措施,不仅保护了环境,而且还可回收数量可观的从原料、成品或半成品。     

Microprofiles of activated sludge aggregates using microelectrodes in completely autotrophic nitrogen removal over nitrite (CANON) reactor

Microsensor measurements and fluorescence in situ hybridization (FISH) analysis were combined to investigate the microbial populations and activities in a laboratory-scale sequencing batch reactor (SBR) for completely autotrophic nitrogen removal over nitrite (CANON). Fed with synthetic wastewater rich in ammonia, the SBR removed 82.5±5.4% of influent nitrogen and a maximum nitrogen-removal rate of 0.52 kgN·m⁻³·d⁻¹ was achieved. The FISH analysis revealed that aerobic ammonium-oxidizing bacteria (AerAOB) Nitrosomonas and anaerobic ammonium-oxidizing bacteria (AnAOB) dominated the community. To quantify the microbial activities inside the sludge aggregates, microprofiles were measured using pH, dissolved oxygen (DO), NH4+, NO2− and NO3− microelectrodes. In the outer layer of sludge aggregates (0–700 μm), nitrite-oxidizing bacteria (NOB) showed high activity with 4.1 μmol·cm⁻³·h⁻¹ of maximum nitrate production rate under the condition of DO concentration higher than 3.3 mg·L⁻¹. Maximum AerAOB activity was detected in the middle layer (depths around 1700 μm) where DO concentration was 1.1 mg·L⁻¹. In the inner layer (2200–3500 μm), where DO concentration was below 0.9 mg·L⁻¹, AnAOB activity was detected. We thus showed that information obtained from microscopic views can be helpful in optimizing the SBR performance.     

Mass concentrations and temporal profiles of PM10, PM2.5 and PM1 near major urban roads in Beijing

Mass concentrations of PM₁₀, PM_2.5 and PM₁ were measured near major roads in Beijing during six periods: summer and winter of 2001, winter of 2007, and periods before, during and after the 2008 Beijing Olympic Games. Since the control efforts for motor vehicles helped offset the increase of emissions from the rapid growth of vehicles, the averaged PM_2.5 concentrations at roadsides during the sampling period between 2001 and 2008 fluctuated over a relatively small range. With the implementation of temporary traffic control measures during the Olympics, a clear “V” shaped curve showing the concentrations of particulate matter and other gaseous air pollutants at roadsides over time was identified. The average concentrations of PM₁₀, PM_2.5, CO and NO decreased by 31.2%, 46.3%, 32.3% and 35.4%, respectively, from June to August; this was followed by a rebound of all air pollutants in December 2008. Daily PM₁₀ concentrations near major roads exceeded the National Ambient Air Quality Standard (Grade II) for 61.2% of the days in the non-Olympic periods, while only for 12.5% during the Olympics. The mean ratio of PM_2.5/PM₁₀ near major roads remained relatively stable at 0.55 (±0.108) on non-Olympic days. The ratio decreased to 0.48 (±0.099) during the Olympics due to a greater decline in fine particles than in coarse-mode PM. The ratios PM₁/PM_2.5 fluctuated over a wide range and were statistically different from each other during the sampling periods. The average ratios of PM₁/PM_2.5 on non-Olympic days were 0.71.     

A numerical method for spherical particle motion in turbulent flow with large Reynolds number

ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｓｏｌｉｄ／ｆｌｕｉｄｔｗｏｐｈａｓｅｆｌｏｗｓａｒｅｏｆｔｅｎｅｎｃｏｕｎｔｅｒｅｄｉｎｍａｎｙｅｎｖｉｒｏｎｍｅｎｔａｌ，ｃｈｅｍｉｃａｌａｎｄｈｙｄｒａｕｌｉｃｅｎｇｉｎｅｅｒｉｎｇ，ｓｕｃｈａｓｓｅｄｉｍｅｎｔｔｒａｎｓｐｏｒｔａｔｉｏｎｉｎｒｉｖｅｒｓ，ｗａｓｔｅｗａｔｅｒｆｌｏｗｗｉｔｈｓｏｌｉｄｐａｒｔｉｃｌｅｓａｎｄｓｏｏｎ．Ｒｅｃｅｎｔｌｙ，ｃｏｎｓｉｄｅｒａｂｌｅｅｆｆｏｒｔｓｒｅｇａｒｄｉｎｇｎｕｍｅｒｉｃａｌｐｒｅｄｉｃｔｉｏｎｓｈａｖｅｂ…     

Exergy and ecological modelling of lake environment

１ＩｎｔｒｏｄｕｃｔｉｏｎＩｎｃｒｅａｓｉｎｇｌｙｓｅｒｉｏｕｓｌａｋｅｅｕｔｒｏｐｈｉｃａｔｉｏｎｈａｓｂｅｃｏｍｅａｇｌｏｂａｌｅｎｖｉｒｏｎｍｅｎｔａｌｐｒｏｂｌｅｍａｎｄｄｒａｗｎｇｒｅａｔａｔｅｎｔｉｏｎ．ＩｎＣｈｉｎａ，ｍａｎｙｌａｋｅｓ...     

宽间距电除尘器在回转烘干机上的应用

宽间距电除尘器是我国“七五”期间开发的高效除尘设备。它优于常规电除尘器,适应粉尘浓度大、比电阻高的烟尘,可捕集10~1～10~4(Ω·cm)的粉尘微粒。当粉尘比电阻为10~(11)(Ω·cm)时,单机除尘效率大于99％,对于0.01μm的粉尘微粒,除尘效率可达90～98％。该种除尘器首次在韶钢应用,取得很好的环境和经济效益。     

Concentrations of Heavy Metals in Muscle with Relation to the Growth of Two Marine Fish Species

Heavy metal concentrations in muscle and their relation to thegrowth of two marine fish species,including tonguefish( Cynoglossus arel) and mullet( Mugil cephalus),were studied. The samples were collected in Bach Dang estuary andconcentrations of heavy metals( As,Cd,Co,Mn,Cu,Zn,Pb,and V) in muscle of the fisheswere determined. The result showed that the accumulated trend of heavy metal is different between fish species. The concentration of As,Zn,Mn,V,Cu,Pb,Co and Cd in tonguefish were 73. 7 ± 30. 6,22. 82 ± 4.87,3. 44 ± 2. 13,1. 61 ± 0. 15,0. 71 ± 0. 13,0. 45 ± 0. 24,0. 03 ± 0. 02 and 0. 02 ± 0. 02 mg·g-1,respectively. Meanwhile the concentration of Zn,As,V,Mn,Cu,Pb,Co and Cd in mullet were 83. 41 ±19. 68,9. 78 ± 1. 92,1. 36 ± 0. 54,1. 29 ± 0. 51,0. 65 ± 0. 12,0. 42 ± 0. 20,0. 06 ± 0. 03 and0. 03 ± 0. 01mg·g-1,respectively. Comparison of metal levels among thesespecies indicated that the concentrations of As and Mn in tonguefish were significantly higher than those in mullet,whereas Zn levels in mullet were found to be higher than that in tonguefish. There is no significant differences of Cd,Co,Cu,Pb and V levels in muscle between two species. Significant inversed relationshipsbetween concentration levels of metals and lengths of tonguefish were found for Mn,Cu and Zn,butnot for As,Cd,Pb,and V. There were no significant relationships between the heavy metal concentrations and the length of mullet. In general,decreasesof the heavy metal concentrations corresponded to the increases of fish body lengths,particularly for As,Co,Cu,Mn and V and the exception for Cd. Terefore reduced risks were associated with consuming biggermullet fish,and increased risks of As and Cd were associated with consuming bigger tonguefish in Bach Dang river mouth.     

Combination of heterogeneous Fenton-like reaction and photocatalysis using Co-TiO2 nanocatalyst for activation of KHSO5 with visible light irradiation at ambient conditions

A novel coupled system using Co–Ti O2 was successfully designed which combined two different heterogeneous advanced oxidation processes, sulfate radical based Fenton-like reaction（SR-Fenton） and visible light photocatalysis（Vis-Photo）, for degradation of organic contaminants. The synergistic effect of SR-Fenton and Vis-Photo was observed through comparative tests of 50 mg/L Rhodamine B（Rh B） degradation and TOC removal. The Rhodamine B degradation rate and TOC removal were 100% and 68.1% using the SR-Fenton/Vis-Photo combined process under ambient conditions, respectively. Moreover, based on XRD, XPS and UV-DRS characterization, it can be deduced that tricobalt tetroxide located on the surface of the catalyst is the SR-Fenton active site, and cobalt ion implanted in the Ti O2 lattice is the reason for the visible light photocatalytic activity of Co–Ti O2. Finally, the effects of the calcination temperature and cobalt concentration on the synergistic performance were also investigated and a possible mechanism for the synergistic system was proposed. This coupled system exhibited excellent catalytic stability and reusability,and almost no dissolution of Co2＋was found.