摘要：A Number 1 fuel heating oil was studied for the organo-nitrogen content. The organo-nitrogen compounds were isolated by mild acid extraction followed by silical gel adsorption. Three extracts were studied - a basic nitrogen extract in methylene chloride, a nonbasic nitrogen extract in methyl alcohol and a nonbasic nitrogen extract in methylene chloride. The major constituents of each extract were identified by GC/MS. There were seven major classes of nitrogen compounds detected in each extract. There compounds included alkyl-substituted carbazoles, indoles, pyrazines, pyridines, pyrroles, quinolines and tetrahydroquinolines. The nitrogen content and distribution was compared to both tar-sands and shale derived fuels.
摘要：The objective of this research was to evaluate the transport and biodegradation of a NAPL (hexadecane) in layered soil. The results indicate that there was limited removal of hexadecane from soil by pumping. Biodegradation of hexadecane occurred throughout the reactor that was amended with nitrogen and phosphorus. Enhanced biodegradation of hexadecane at the soil textural interfaces was not observed. Bioremediation systems located in layered soil must be carefully designed to encourage complete remediation throughput the contaminated zone.
摘要：Theoretical and experimental investigations were conducted on the adsorption characteristics of 1,1,1,2-terafluoroethane (HFC-134a) by granular and extruded activated carbons (GAC and EAC). HFC-134a is currently regarded as an excel-lent replacement for CFC-12 (Freon 12), a refrigenant previously used in all automobiles and many cooling systems. Experimental results of column adsorption were employed to verify the theoretical bread through curves generated from the pro-posed model and excellent model fit of the breakthrough curves of HCFC-134a adsorption were obtained. Investigations were also made on the effects of gas velocity, inlet HFC-134a concentration and operating temperature on the adsorption efficiency.
摘要：This work presents results of a feasibility study for removal of heavy metal contaminants from water using aquatic plants. A local strain of Cladophora was used to remove cadmium from a synthetic wastewater. The algae were grown in a laboratory using natural water under the following conditions: pH controlled between 7.8 and 9.0, 18 hrs of light/day, occasional application of plant fertilizer. Cadmium was added to the water in two modes - one time addition of a large dose of heavy metal (concentration 5 mg Cd~+2/L), and several small, equal doses (each 1 mg Cd~+2/L), added everyday. Experiments were replicated to verify reproducibility. In all sets, removal of cadmium (in a range of 8 days) varied from 86/100 to 96/100, based on the residual concentration in the water. Percentage of removal calculated from digestion of biomass closely approximated these values (within 20/100). High degrees of removal were observed in the first 48 hours. Concentration factors ranged from 1340 to 16,400. Concentration of cadmium (Cd~+2) was found to be as high as 1.64/100 of the dried cellmass. The Relative Growth, RG (Final Fresh Weight/Initial fresh Weight) indicated good growth of plant biomass, albeit constant exposure to cadmium.
摘要：The objective of this study was to identify preliminary and other factors that could be used to screen surface waters before embarking on the expensive laboratory procedure. In order to determine which public water systems that are groundwater under the direct influence (GWUDI), a total of 62 wells at public water supplies suspected of being (GWUDI) were investigated. The wells sampled were distributed acorss seven counties in the Central Florida region. Water samples were collected and analyzed at the Department of Health Laboratory in Tampa, Florida using the Micorscopic Particulate Analysis (MPA). The study investigated the well and hydrogeologic characteristics, and land use within the vicinity of the well locations. The results showed that 13/100 of the wells sampled were in the high-risk range while 29/100 and 58/100 of the wells sampled were within the moderate and low risk ranges, respectively. It was also observed that some well characteristics and the hydrogeology of an area generally influence the MPA risk index. Karst regions were observed to be susceptible to a higher risk than sandy areas. The results also suggested that older wells tend to have higher risk index.
摘要：Conditional simulation, kriging and trend surface analysis techniques have been widely used in the studies of spatial features of variables because of their characteristics of explaining spatial distributions and structures of variables. The purpose of this study is to make an experiment in applying these techniques for illustrating spatial distribution and structural characteristics of heavy metals (Cu and Pb) in agricultural soil irrigated with wastewater in the eastern outlying farming areas of Beijing. Results show that with the rapid development of computer technique in recent years, both the kriging and conditional simulation techniques can play better roles in providing more precise solutions to soil pollution issue than the trend surface analysis. In comparison, kriging interpolation can be applied to find out the optimum estimation, while condition simulation is favorable for identifying the spatial variety and the fluctuation pattern of the pollutants in the soil, With feasible utilization, both these methods could be powerful tools in soil pollution study, including determining the pollution area, evaluating the pollution level and identifying the pollution sources which would contribute to successive planning and remediation processes.
摘要：The leaching and stabilizing characteristics of synthetic copper diethyl dithiocarbamate (Cu-DDTC) under 1 N acetic acid solution were characterized using semi-dynamic leaching test (SDLT), ultraviolet-visible spectrophotometer (UV-visible), X-ray diffractometer (XRD), Fourier transform infrared spectrophotometer (FTIR), and scanning electron microscopy (SEM) techniques. The analyses of leached species of leaching solution by SDLT and UV-visible indicated that the degree of degradation of various elements from the Cu-DDTC complex could be classified as: N (25/100)> S (20/100) > Cu(0.7/100) and no dithiocarbamate species in the liquid phase were detected. The copper species of insoluble Cu-DDTC complexes were much more stable than those of copper solidification in cementitious matrix. The investigation of crystallinity showed that there were two unidentifiable peaks present in the XRD pattern of the leached Cu-DDTC complex that might be attributed to new chemical interactions. The spectra obtained by FTIR analyses obviously showed that the major functional groups, such as C-N, S-C, C=S, Cu-S and C-H groups, were both present in the unleached and leached Cu-DDTC complex. Microstructural analyses by SEM revealed that the unleached and leached Cu-DDTC complexes had the same morphologies, but the grain size of the leached Cu-DDTC complex is much larger and compact than that of the unleached complex. Thus, it was suggested that the leaching and stabilizing characteristics of the insoluble Cu-DDTC complexes consisted of the dissolution and decomposition of Cu-DDTC and the chelatin
摘要：To determine the temporal variation in the levels of polychlorinated dibenzop-dioxins (PCDDs) and dibenzofurans (PCDFs) in vegetation grown near an old municipal solid waste incinerator (Montcada, Barcelona, Spain), 24 herbage samples were collected at the same sampling points in which samples has been taken one year before. While in the previous survey PCDD/F concentrations ranged from 1.07 to 3.05 ng I-TEQ/kg (dry matter) (median value: 1.88 ng I-TEQ/kg, mean value: 1.92 ng I-TEQ/kg), in the current samples PCDD/F levels ranged from 0.75 to 1.95 ng I-TEQ/kg (dry matter) median value: 1.27 ng I-TEQ/kg, mean value: 1.30 ng ITEQ/kg). An individual comparison between PCDD/F concentrations in samples collected in both studies shows a decrease in all the sampling points with an average reduction of 32.3/100. This reduction can be due to general abatement actions for PCDD/F emissions.
摘要：In this research, lime-treated montmorillonite clay is used to adsorb Zn(II) in a wide range of Zn(II) concentrations. Batch test results show that the adsorption of Zn(II) by montmorillonite appears to be dominated by different adsorption mechanisms. At low Zn(II) concentrations, chemisorption affects the amount of Zn(II) adsorbed by montmorillonite. When lime is added, physisorption becomes increasingly important. At high Zn(II) concentrations, physisorption is the dominnt mechanism for Zn(II) adsorption. Lime also enhances the ability of montmorillonite to adsorb Zn(II) at low initial Zn(II) concentrations, and does not significantly affect the ability of montomorillonite to adsorb Zn(II) at high initial Zn(II) concentrations. In chemisorption, montmorillonite provides cation exchange sites for the adsorption of Zn(II). In physisorption, montmorillonite acts as not only numcleation center to adsorb zinc hydroxide-oxides but also helps to coagulate the zinc hydroxide-oxides. Lime-treated clay can therefore be an effectively used to adsorb metals such as zinc even at very high metal concentrations. The significance of these findings is in the design of landfill liner. A mixture of montmorillonite (bentonite) clay and lime is shown to have characteristics that would make this material a superior landfill liner. The lime-treated clay has low hydraulic conductivity, enhanced metal removal capability, and better resistance to penetration by sharp objects.
摘要：The concentration of Seven heavy metals (copper, Cadmium, iron, chromium, manganese, lead and zinc) have been evaluated at twenty important ground water sampling stations at Dhanbad town for three seasons of the year. The concentration of heavy metals in general was found to be below the permissible levels although concentration of iron and manganese was found above the permissible limits at a few stations. These data have were for the calculation of Heavy Metal Pollution Index (HPI). The HPI of ground water was found to be far below the index limit of 100 pointing to the fact that the ground water was not polluted with respect of heavy metals in spite of the prolific growth of mining and allied industrial activities near the town.
摘要：A number of microorganisms were isolated from sewage. Biochemicla oxygen demand (BOD) analysis was carried out by using these isolated microorganisms as a seed material with glucose-glutamic acid (GGA) as a reference standard. Based on the BOD values, a defined microbial composition was formulated by using these isolates. This formulated microbial composition was standardized for reproducible BOD estimation by using four synthetic and four industrial samples. The results showed reproducibility of the BOD values within an acceptable limit. The BOD results are comparable with sewage which is used as a seed material in conventional BOD analysis. Storage stability studies of formulated microbial composition t different temperatures showed the maximum stability at 4degC. Such microbial composition offers better opportunity to be used as a standard seed inoculum in the BOD test.
摘要：Due to its reliability, simple and portable structure and low costs, the passive sampler is the ideal measuring device for developing countries. In spite of this, there has been no reporting on its reliability in extremely low temperate areas such as those associated with Northeastern China. The measuring of SO_2 by passive samplers was attempted at extremely low temperatures in the heavy industrialized area of Shenyang, China from December 25 to 28, 1995.
摘要：The ChemChar process enables gasification of a wide variety of liquid and sludge wastes on a readily handled macroporous granular char. The process produces combustible gas products, largely retains metals and halides on the char matrix, and effectively destroys organohalides without producing SOx, NOx, chlorinated dibenzodioxins or chlorinated dibenzofurans (which can occur with incineration). To study chemical warfare agent wastes under gasification conditions, the destruction removal efficiencies (DRE) of the chemical warfare surrogates parathion and diethylchlorothiophosphate were determined. DREs of > 99.99998/100 and >99.99998/100 were found for parathion and diethylchlorithiophosphate, respectively. Additionally, a study of the distribution of radiolabeled phosphorus (P-32) after gasification of parathion and tributylphosphate showed essentially complete retention of the phosphorus within the gasification system. This study illustrates that the ChemChar gasification process holds significant promise as an alternative to incineration for the safe and complete destruction of chemical warfare agent wastes.
摘要：The impact of temperature on biokinetic constrants used in the design and operation of activated sludge treatment facilities is presented. Three temperatures (10 deg C, 20 deg C, and 30 deg C) are evaluated for their impact on substrate removal, biomass concentration, waste sludge production,a nd oxygen requirements. The biokinetic equations developed by Lawrence and McCarty (1970 ) are utilized.
摘要：The treatment of synthetic dairy wastewater was carried out using cross flow medium trickling filter of specific surface area 243 m~2/m~3. The operating variables in this study were hydraulic and organic loading rtes. The hydraulic loadings employed in this study were 5,9,13 and 17 m~3/m~2.d for the influent COD concentrations of 427 to 1384 mg/1. It was observed that the relationship between organic removal rate and organic loading rate showed two regions of linear behaviour with the point of inflection at an organic loading rate of 26 g COD/m~2.d. Kornegay model was used to evaluate the kinetic coefficients for the system. The results were found to be satisfactory.
摘要：In this study an attempt was made to develop a reliable method for the estimation of total oil hydrocarbons in sediments. The method developed involved an HPLC technique using a group separation. The oil was separated into saturates, aromatics and polar compounds after removing the asphaltenes gravimetrically. Determination was carried out by quantifying the aromatics and polar hydrocarbon fractions of a reference oil (Arabian light), against which the unknown was assayed. Linear calibration curves were obtained for the aromatics and polar fractions over the range 1-12 mg/mL and 0.1-1 mg/mL, respectively. The reproducibility for the aromatics fraction was acceptable with a maximum error of 2.8/100 (n=3) and recovery rate was 89.3/100 (n=3). Similar results were obtained for the polar fraction. The method was compared with an existing Spectrofluormetric method.
摘要：Electrochemical treatment was shown to be successful in removing from solution two acid dyes used in the carpet industry. The Andco Environmental Processes laboratory scale iron electrode system was shwon to decolorize solutions of Acid Red 337 (azo) and Acid Blue 40 (anthraquinone). High performance liquid chromatography (HPLC) with diode-array detection was used to quantify dye removal and provide qualitative information about degradation products. Both degradation and adsorption contribute to removal of Acid Red 337; adsorption appears to be the primary mechanism responsible for removal of Acid Blue 40. Addition of sodium meta-bisulfite to the Andco system was shown to enhance removal of both dyes. It is postulated that the dithionite and/or sulfoxylate radical anion that may be formed during the reduction of bisulfite is responsible for the more efficient cleavage of the azo linkage in Acid Red 337, causing further degradation. The mechanism for enhanced removal of Acid Blue 40 by addition of meta-bisulfite is most probably due to reduction of the anthrquinone dye to hydroquinone, which in its leuco form adsorbs better to the iron solids generated in the electrochemical treatment process.
摘要：A comparative biosorption of chromium (VI) ions to Ca-alginate and agarose biopolymers and immobilized C. vulgaris, a green alga was investigated. The experiments were carried out in a packed bed column operated in a continuous mode, as a function of the flow rate and inlet chrominum(VI) ion concentration. The removal percentage of chromium(VI) ions related to the effluent volumes were also determined. Agarose and agarose - algae systems showed a rapid chromium(VI) uptake initially while chromium (VI) ion adsorption to Ca-alginate and Ca-alginante was limited initially by the diffusion of the solute through the pores. Ca-alginate was not a good biosorbent for chromium(VI) ions and immobilization of C. vulgaris to Ca-alginate only marginally increased the biosorption yield. However, agarose and agarose immobilized C. vulgaris increased the biosorption capacity. Total chromium(VI) removal by agarose and agarose-C. vulgaris systems were higher than that of Ca-alginate and Ca-alginate immobilized C. vulgaris at the same time interval.
摘要：The five important parameters to characterize tannery effluents viz. total chromium sulfide, TDS, BOD and COD were determined for samples obtained from different streams as well as for composite liquor. The remedial measures to contain their pollution load on the treatment plant are discussed. The correlation between TDS and BOD, TDS and COD for the these samples are also reported.
摘要：Mutants of pseudomonas fluorescens were used for inoculation of bean (Phaseolus vulgaris L.) at different growth stages to assess their impact on indigenous culturable heterotrophic bacteria in the rhizoshere. Survival of inoculants, changes in numbers of the indigenous bacteria and their physiological state, and microbial community structures were determined using a simple agar plating method. The results showed that survival of introduced P. fluorescens mutants varied according to the growth stage of bean inoculated. However, overall, the mutants survived better in the rhizoshere with time, when they were inoculated on seeds. In contrast to some authors, the effect of mutants introduced was observed in the case of indigenous bacterial numbers and microbial community structures. Overal, no significant treatment effect was observed, when changes n values of kinetic parameters of colony formation were considered. Generally, cfu numbers, physiological state and community structure of indigenous microflora in the rhizoshere were depended on the effect of the interaction between the inoculants, the time after the introduction and the growth stage of plant.