超临界流体色谱及超临界流体提取技术在农药分析中的应用

农药分析中目前用得最多的是气相色谱和液相色谱仪。气相色谱仪以气体作为流动相;液相色谱仪以液体作为流动相;用超临界流体作为流动相则为超临界流体色谱仪(Supercritical Fluid Chrormatography)。这是80年代发展和完善起来的一种新技术,在农药分析中已得到多方面的应用。所谓超临界流体是物质处在其临界温度及临界压力上的状态,介于气态和液态之间,因而兼有气体和液体的某些物理性状。若气体温度高于其临界温度时。

Research status of carbonaceous matter in carbonaceous gold ores and bio-oxidation pretreatment

Carbonaceous gold mines are important refractory gold ores. The previous results demonstrate that the carbonaceous matter is mainly composed of elemental carbon, organic acid and hydrocarbons. The dissolved aurocyanide complex is robbed by adsorption of carbonaceous matter, which is similar to activated carbon in cyanide leaching of gold. The pretreatment methods of carbonaceous gold ores were introduced, including high temperature roasting, bio-oxidation, chemical oxidation, competitive adsorption, barrier inhibition and microwave roasting. Recently, bio-oxidation was developed rapidly due to its advantages such as mild conditions, simple processes, low energy consumption and friendly environment. The known microorganisms related with bio-oxidation pretreatment mainly are chemolithotroph bacteria such as Thiobacillus ferrooxidans, Thiobacillus thiooxidans and Leptospirillum ferrooxidans. The researches on decomposing and passivating carbonaceous matter were commenced by Phanerochaete chrysosporium, Pseudomonadaceae and Streptomyces setonii. Finally, the main problems were analyzed and the application prospect of this technique was looked forward.

Ozonation and Biodegradability of Lignin in Water

To convert the non biodegradable sodium lignin sulfonate into biodegradable substances, the sodium lignin sulfonate in the water was ozonized and the pH value, dissolved organic carbon(DOC), ultraviolet absorbency at λ =254 nm(UVA) and the biodegradability of the ozonation effluent were measured. The non biodegradable sodium lignin sulfonate can be partly converted into biodegradable substances by ozonation (about 38 76%). In the ozonation process, there is little DOC decrease, but much UVA decrease and obvious pH drop.

累惯犯分押工作的几点实践思路

近几年白茅岭教导大队在认真调研的基础上,对盗窃型累惯犯实施了一套以“三级五等”为基本分极管理框架、低报酬有偿劳动为主要物质处遇的分管模式。本文仅对在设计该模式过程中的几点思路,再作些介绍以供借鉴。

Studies on Recovery Efficiencies of Phenols from Phenol Fraction Using Alkali Treatment

Experiments were conducted for the extraction of phenols from the phenol fraction obtained from the coal tar distillate. The phenol fraction for the present investigation has been procured from Visakhapatnam Steel Plant, Visakhapatnam whose composition is known. The phenol fraction from coal tar distillate can be treated for extracting phenols using caustic soda. An attempt has been made to find out whether the existing practice of using only 8%-15% can be modified by increasing the strength of sodium hydroxide and also explore the possibilities of substituting the sodium hydroxide with KOH as an extractant. The different streams of liquids obtained during experimentation have been analyzed by gas chromatograph. Salient features of the study are that higher concentrations of the alkali significantly improved the separation efficiencies of phenols and also regenerate the phenolate with higher phenol content. Increase in the alkali strength has greatly improved the separation as well as the phenol content in the regenerated phenols. Disposal of effluents containing phenols may lead to environmental problem of ground water pollution and the study throws a light on the removal of phenols from the effluents to the extent possible by using higher strength alkali solutions.

The influence of anoxia design and change aerations time on the treatment from coke plant wastewater

According to a great deal of experimental findings and the oretical analysis, theperformance of SBR process treating organic substance and ammonia was presented for different operating pattern and aeration time.When the operation mode is feeding water,anoxie mixing 2.5 h, settlement, and draining for 1.5 h, the coke plant wastewater can be treated well by the SBR method.

Removal of cyclops in pre-oxidizing cooperation water treatment process

Zooplankton cyclops propagates profusely in waterbody, cannot be effectively inactivated by conventional disinfection process, and becomes a troublesome drinking water treatment problem. In this work, the qualitative and quantitative experimental studies were carried out on inactivation of zooplankton cyclops using oxidants, such as chlorine （Cl2）, chlorine dioxide （ClO2）, ozone （O3）, hydrogen peroxide （H2O2）, ozone/hydrogen peroxide （O3/H2O2）, chloramines （Cl2-NH3） and potassium permanganate （KM4nO4）. The influences of various factors include different oxidant dosages, organic substance contents and pH values. The results showed that currently available oxidants used all might inactivate cyclops in some extent. According to the experimental results, chlorine dioxide, ozone, ozone/hydrogen peroxide and chloramines can be selected as effective oxidants for inactivating cyclops because of their strong inactivation abilities. Then the synergic removal effects on cyclops with ozone, ozone/hydrogen peroxide pre-oxidation followed by conventional water treatment processes were investigated, The results showed that ozone and ozone/hydrogen peroxide pre-oxidation can inactivate cyclops effectively, which then can be removed thoroughly by conventional water treatment processes. Cyclops cannot appear in water after filtration with 1.65 mg/L of ozone and 6 mg/L of hydrogen peroxide, with the inactivation rate being 62% before conventional water treatment processes. Cyclops cannot appear in water after filtration with 1.8 mg/L of ozone, with the inactivation rate being 50% before conventional water treatment processes. For different oxidants, when removal rate was the best, the inactivation rate was not the same. These results may provide reference and model for actual waterworks.

Study on the removal of toxic substance from river water using O_3-GAC process

This paper studied on the removal of toxic substance from river water using O3-GAC process. The result of GC/MS analysis indicated that the number of organic compound species was decreased by 55.1%. The species of toxic substance of raw water also decreased from 16 to 5. The total removal rate of CODMn andUV254 were 45%～72% and 60%～80% following O3-GAC treatment. It reflected that this process had a good effective on removing unsaturation organic which absorb UV and toxic organic containing nitrogen. The results of Ames test indicated that raw water had a relatively strong mutagicity on TA 98. The O3-GAC process had a good ability in removing mutagen in water. The effluent water’s mutagicity is minus. The results of the study indicated that the effluent of the O3-GAC process was meet the demand of drinking water.

Characterization of Thailand Rice Husk Ash from Biomass Power Plant and Synthesized Zeolite

Thailand rice husk ash was used to synthesize zeolite by hydrothermal treatment. Raw rice husk ash material and zeolitic products were characterized in terms of specific surface area （BET method）, morphological analysis （SEM）, mineralogical composition （XRD） and CEC （cation exchange capacity）. LOI （Loss of ignition） of rice husk ash was also evaluated. Result indicated that the rice husk ash sample from Roi-Et Green power plant in the Northeastern of Thailand with combustion temperature of 650 ℃ has a high content of SiO2 （above 90 wt.%）. Zeolite-X from rice husk ash with high content of Si was successfully synthesized using hydrothermal treatment. The zeolitic material synthesized with the optimal condition possessed a maximum value of CEC of 503 meq/100g, and it has potentiality to be used as ion exchangers.

The Effect of Non-acidified Wastewater on Expanded Granular Sludge Bed （EGSB） Reactors Performance

The textile processing plants utilize a wide variety of dyes and other chemicals such as acids, bases, salts, detergents, sizes, oxidants, mercerizing and finishing chemicals. Many of these are not retained in the final product and are discharged in the effluent. Therefore, the objective of this study was to assess the performance of EGSB （Expanded Granular Sludge Bed） reactor to treat non-acidifie wastewater. Several experiments using starch and volatile fatty acids as model substrates were conducted. The problems of piston formation were evaluated at a variety of relevant operational conditions, such as substrate concentration, organic and hydraulic loading rates. The results showed that newly grown acidogenic biomass diluted original methanogenic biomass and the granular sludge in the EGSB reactor deteriorated. The piston formation in the EGSB reactor that was fed with non-acidified wastewater occurred due to high growth of acidogenic biomass and high upflow velocity applied in the system.

From pollutant to solution of wastewater pollution: Synthesis of activated carbon from textile sludge for dye adsorption

Adsorption is an important process in wastewater treatment,and conversion of waste materials to adsorbent offers a solution to high material cost related to the use of commercial activated carbon.This study investigated the adsorption behaviour of Reactive Black 5（RB5）and methylene blue（MB）onto activated carbon produced from textile sludge（TSAC）.The activated carbon was synthesized through chemical activation of precursor followed with carbonization at 650℃ under nitrogen flow.Effects of time（0–200 min）,pH（2–10）,temperature（25–60℃）,initial dye concentration（0–200 mg·L^-1）,and adsorbent dosage（0.01–0.15 g）on dye removal efficiency were investigated.Preliminary screening revealed that TSAC synthesized via H2SO4activation showed higher adsorption behaviour than TSAC activated by KCl and ZnCl2.The adsorption capacity of TSAC was found to be 11.98 mg·g^-1（RB5）and 13.27 mg·g^-1（MB）,and is dependent on adsorption time and initial dye concentration.The adsorption data for both dyes were well fitted to Freundlich isotherm model which explains the heterogeneous nature of TSAC surface.The dye adsorption obeyed pseudo-second order kinetic model,thus chemisorption was the controlling step.This study reveals potential of textile sludge in removal of dyes from aqueous solution,and further studies are required to establish the applicability of the synthesized adsorbent for the treatment of waste water containing toxic dyes from textile industry.

Characterization of the start-up period of single-step autotrophic nitrogen removal in a sequencing batch reactor

The characteristics of the start-up period of single-step autotrophic nitrogen removal process were investigated. The autotrophic nitrogen removal process used a sequencing batch reactor to treat wastewater of medium to low ammonia-nitrogen concentration, with dissolved oxygen （DO）, hydraulic retention time （HRT） and temperature controlled. The experimental conditions were temperature at （30±2） ℃, ammonia concentration of （60 to 120） mg/L, DO of （0.8 to 1.0） mg/L, pH from 7.8 to 8.5 and HRT of 24 h. The rates of nitrification and nitrogen removal turn out to be 77% and 40%, respectively, after a start up period going through three stages divided according to nitrite accumulation： sludge domestication, nitrifying bacteria selection and sludge adaptation, It is demonstrated that dissolved oxygen is critical to nitrite accumulation and elastic YJZH soft compound packing is superior to polyhedral hollow balls in helping the bacteria adhere to the membrane.

Medium-Deep or Very Deep Disposal of Highly Radioactive Waste？

Commonly proposed concepts, like KBS-3V, for disposal of highly radioactive waste imply construction at medium depth （400-600 m） in granitic rock, which is excellent for constructing a stable repository. VDH （very deep boreholes） represent an altemative concept with the advantage that the rock is much less permeable and that the very salt, heavy groundwater is stagnant. Both require engineered barriers in the form of canisters and waste-embedding clay but for somewhat different purposes. Canisters are the most important waste-isolating barriers for KBS-3V but are less important for VDH. The waste-embedding clay is needed for preserving the KBS-3V canisters by being tight and ductile, but plays a minor role for the VDH. The backfilled deposition tunnels in a KBS-3V repository provide very limited hindrance of radionuclides to move to the biosphere while the clay seals of VDH effectively prevent possibly released radionuclides to reach up to the biosphere. Comparison of the KBS-3V and VDH concepts indicates that the last mentioned one has several advantages but that certain issues remain to be worked on for becoming a number one candidate.

Use of Waste Vegetable Biomasses Treated by Steam Explosion for the Horticultural Crop Protection

The purpose of this study was to assess the suppressive effect of Waste Vegetable Biomasses （WVBs） treated by the Steam Explosion technique in a continuous plant, against soil-borne plant pathogens. In order to assess their disease suppression, five WVBs （Miscanthus biomass, durum wheat straw, rice straw, corn stalk and wood shaving） and commercial compost were tested in vivo at three different doses （10, 20 and 30% of potting mix） on seven horticultural pathosystems plant/fungus： tomato/Phytophthora nicotianae, cucumber/Pythium ultimum, lettuce/Fusariurn oxysporum f. sp. lactucae, melordFusariurn oxysporum f. sp. melonis, bearffRhizoctonia solani, eggplant/Verticillium dahlie and fennel/Sclerotinia sclerotiorum. The results showed that the corn stalk was more efficient respect to Miscanthus, compost, wheat straw, rice straw and wood shaving in all the patbosystems and at all the doses tested. The corn stalk suppression ranged from 97% in eggplant/F, dahliae to 35% in lettuce/F, oxysporum f. sp. lactucae, and it was significantly higher with respect to the other substrates. In general, the wheat straw, rice straw and wood shaving were statistically found less efficient as suppressive substrate with respect to corn stalk, Miscanthus and compost at the 30% dose in four pathosystems In particular, the wood shaving suppressiveness ranged from 48% in eggplant/V, dahliae to 12% in lettuce/F, oxysporum f. sp. lactucae. The different suppressiveness observed could be attributed to different concentration of the microbial inhibitory substances （furfurals, organic acids and lignosulfonates） produced during the processing of fresh biomass.

Risk Communication： Survey on Quality of Safety Data Sheets of Agricultural Substances

Manufacturers of chemicals are responsible for setting up a list of tools, including labels and safety data sheets, in order to provide adequate information about dangerous properties being labels and safety data sheets the main instruments for the immediate advice about dangerous substances and preparations for general public and workers. While correct labelling gives the possibility to general public to recognise the risks arising from handling and use of dangerous chemicals, safety data sheets are provided for professionals in order to allow safe handling and storage of dangerous chemicals in work places. Information contained in safety data sheets are also designed to suggest safety measures to be taken for the protection of workers as well as precaution measures and adequate actions to be taken in the case of accident. This project has critically revised the information contained in a list of safety data sheets of active ingredients provided for plant protection products, in order to assess the quality and the consistency of the data contained. Reported data have been then compared to published data. Considerable deficiencies/mistakes/inconsistencies have been found in the data reported along the safety data sheets of the examined substances, showing an urgent need of improving the enforcement related to a systematic recognition in this field as well as training of people involved in compilation of safety data sheets by producer side.

Temporal Changes on Pollutants Associated with Sewage Sludge

A field survey was carried out to collect monthly samples from sewage sludge beds. The samples were collected from three sewage treatment plants namely; Jahra, Rekka, and Um Al-Hayman; over 12 months＇ period started from January and ended by December 2002, 2004 and 2006 to assess the temporal changes on the pollutants associated with sewage sludge. The collected samples were analyzed for organic matters, nutrients and heavy metals. It was observed that the quantities of organic matter, organic carbon and nutrients were varied in a wide range of values. The levels of heavy metals were generally below than reported by the Kuwait Environment Public Authority Limits for application of dry sludge. Temporal changes in the levels of heavy metals and other pollutants may be affected by temporal variation in the level of heavy metals, nutrients and organic matters in the influent of wastewater or in the efficiency of the treatment involved.

Distribution of Extracellular Polymeric Substances in Pilot-Scale Membrane Bioreactor

The spatial distribution of extracellular polymeric substances （EPS） in a pilot-scale membrane bioreactor （MBR） was studied. The sampling points on top of and inside the membrane module were measured and analyzed by the experimental variant function. The content of EPS was spatially interpolated by ordinary Kriging method, and il- lustrated with SURFER software. A case study was carried out in an MBR with membrane aperture of 0.4 ~tm and handling capacity of 120 ma/d in Jizhuangzi sewage treatment plant, Tianjin. From the visualization of EPS distribu- tion, it is seen that on the horizontal plane, the content of EPS was the lowest at the center; and on the vertical plane, the content of EPS decreased with the increase of depth. The shearing force caused by aeration of perforated pipe and the influent mode are the main influencing factors for this distribution.

Proposed Flexibility to USA Nuclear Waste Management Strategy

USA nuclear waste management program has stalled due to its continued insistence upon using Yucca Mountain for its disposal of DOE （Department of Energy） and commercial power plants NSF （nuclear spent fuel）. Increased flexibility and significant changes in DOE program are proposed. They include a private waste company to manage it; the construction and operation of ICS （interim centralized storage） facilities for NSF; the search for an AGR （alternate geological repository）; the use of a different methodology involving key local and state participants; a new ＂as safe as practical＂ strategy with defined benefits to the involved locations and states. Assured removal of NSF from ICS and providing limited Price Anderson indemnity for the program will enhance its acceptance. Minimum politics, regular information meetings, compromises, good cost projections and meeting schedules will be necessary to increase the chances of the proposed nuclear waste management program.

Development of a Biological Filter Utilizing Organic Growth Media for Wastewater Treatment and Nitrogen Oxidation

Loss of ammonia-nitrogen to volatilization and the over application of phosphorus in agricultural wastewaters has led to excess phosphorus build up in topsoil and in surface waters. In order to increase the usable amount nitrogen in agricultural wastewaters, the wastewaters underwent a nitrogen treatment process consisting of a hanging basket biological filter. The filters utilized never before used biological growth media, rice hulls, to assist in the formation of a mature biofilms as the oxidation of ammonia to nitrate. The filter design was used on a lab scale that treated both artificial wastewater and dairy parlor wastewater treated with a lime precipitation step for phosphorus treatment. The filters were tested to see if bio-fouling occurred in the filter media bed under high nitrogen loading, if the rice hulls could withstand an extended time frame as bacterial growth media, and to see if the oxidation of ammonia to nitrate would occur. A 50% reduction in ammonia occurred between 30 and 48 hrs in each trial with eventual nitrite oxidation reported in the final two trials. Statistical analysis preformed determined that the ammonia removal rates at the beginning of both the synthetic wastewater and dairy parlor wastewater ten-day tests were statistically similar, but varied toward the end of the trials.

Solid Particle Emission Abatement from Biomass-Fired Boilers at District Heating Plants

The district heating company ＂Rigas siltums＂ operates biomass fuelled boiler in Riga city. Three systems consisting ofbiomass boilers having a comparatively similar heat capacity and particle abatement units like multicyclons, electrostatic precipitators and flue gas condensers are compared. The main goal of the study is to evaluate the boiler plant as a system where solid particles are both emitted and caught. The results show that, the particulate matter can be efficiently trapped from flue gases by the particle abatement technologies, and the electrostatic precipitator with sufficiently large collection surfaces is able to provide appropriate flue gas treatment of the particulate matter in the biomass boilers also without pre-cleaning of the flue gas in multieyelons.