摘要:

Very little attention has been paid to the stormwater runoff quality from log storage and handling facilities. This project determined the concentrations of conventional parameters such as BOD5, COD and TSS, and 123 priority pollutants of stormwater runoff samples from a log storage and handling facility in Louisiana. No significant levels of priority pollutants were found and only about 1 to 13 % of COD was biodegradable. COD followed closely with TSS, suggesting that effective control of TSS will control COD as well. The pollutant strength resulting from summer to fall storms did not vary much.

ISSN:1093-4529    

DOI:10.1080/10934529809376725

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

The genes coding for toluene monooxygenase (TMO), an enzyme also capable of degrading trichloroethylene (TCE), fromPseudomonas mendocinaKR1 were cloned into both narrow‐ and broad‐host‐range vectors and introduced intoEscherichia coliandP. putida.TMO activity expressed by a number of strain/plasmid combinations was assayed by determining decreases in the fluorescence of indble. Degradation of TCE was investigated in sealed serum vials for a number of these combinations. Finally a kinetic experiment, involving determination of the rate of TCE degradation at various TCE concentrations, was performed, and approximate kinetic constants for TCE degradation by these two species were determined.

ISSN:1093-4529    

DOI:10.1080/10934529809376726

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Polychlorinated dibenzo‐p‐dioxins (PCDDs) and dibenzofurans (PCDFs) were analyzed by GC/MS in 24 vegetation samples collected in the vicinity of a municipal solid waste incinerator. Samples were taken within a radius of 3000 m from the stack in each of the three main wind directions in that area. Total TEq levels for PCDD/Fs ranged between 1.07 ng/kg (dry matter) and 3.05 ng/kg (dry matter), with median and mean values of 1.88 y 1.92 ng/kg (dry matter), respectively. OCDD/F and 1,2,3,4,6,7,8‐HpCDD/F were the dominating dioxin and furan congeners found in vegetation samples. Although the highest PCDD/F level (3.05 ng TEq/kg) was found at the north‐west (1000 m from the stack) direction, for most congeners and contributors to Teq the highest concentrations were observed at distances less than 250 m from the facility. The present results should be of concern for future assessments on the correlation between decreases in the atmospheric PCDD/F emission from the incinerator and the decline in the levels of PCDD/Fs in vegetation.

ISSN:1093-4529    

DOI:10.1080/10934529809376727

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

The half‐life of di‐isopropyl methylphosphonate (DIMP) in ground water at 10°C was estimated to be 500 years with a 95% confidence interval of 447 to 559 years from measurements of the hydrolysis rates at four temperatures ranging between 70 and 98°C. First‐order kinetics were assumed, and the Arrhenius equation was used to extrapolate the hydrolysis rates to the normal temperature of ground water, 10°C. The half‐life calculated at this temperature for ASTM Type II water was estimated to be 684 years with a 95% confidence interval of 470 to 995 years, in agreement with a previously published study. The major hydrolysis products detected were isopropyl methylphosphonic acid and methylphosphonic acid. After heating samples for 43 days at 90°C, the molar accounting of the remaining DIMP and its detected hydrolysis products was 15% of the starting material. Inorganic phosphate was not detected. The very slow rate of DIMP hydrolysis in ground water suggests that the unidentified products are not likely to accumulate to any significant extent.

ISSN:1093-4529    

DOI:10.1080/10934529809376728

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

The leaching behaviour of an alkaline lignite fly ash was studied by standard tests, such as the USEPA Toxicity Characteristic Leaching Procedure (TCLP), and German DIN 38414 S4 batch and successive leaching tests. The release of both heavy metals and polynuclear aromatic hydrocarbons was investigated. The quantities of toxic substances released were compared to the total amount of these in the fly ash when measured after dissolution in royal water (for heavy metal determination) and ultrasonic extraction in cyclohexane (for the polynuclear aromatic hydrocarbons). In general, only sulphur was released in considerable quantities, reaching a quarter of its total amount in the fly ash. Toxic metal ions were released in extremely low quantities due to the alkaline nature of the fly ash. PAHs were identified at the solid phase in concentrations less than 100 ppb, while no release in the water phase was detected. The EPA standard test gave higher concentrations of metals in the leachate due to the lower pH conditions of the test.

ISSN:1093-4529    

DOI:10.1080/10934529809376729

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Experiments were conducted to evaluate the performance of two phase anaerobic reactor with membrane separation. Starch was used as substrate. The cartridge type filter of microfiltration (MF) membrane with pore size of 0.2 to 10μm was tested in this research. Acid conversion rate and methane production rate were more effective in acidogenic reactor with membrane system compared with the one with conventional settling tank. The conversion efficiency from substrate to organic acid was in the range of 34% to 50% at the loading rate of 5.0 kg COD/m3. day. Through the all runs, the proportion of acetic acid was 40–45% and that of propionic acid was 30–35 %. The COD reduction in the AUBF was over 90 % at the loading rate of 3.0 kg COD/m3. day. This research may provide the basis of fundamental knowledge for anaerobic treatment and its application to industrial and livestock farming wastes.

ISSN:1093-4529    

DOI:10.1080/10934529809376730

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

A soil sampling program is the most direct means of determining the types, concentration/activity, and distribution of radionuclides within and around nuclear facilities. Los Alamos National Laboratory (LANL), for example, has had a soil surveillance program since the early 1970s and the purpose of this paper was to 1) evaluate this 20+ year data set to determine if there are any statistical differences in radionuclides (3H,137Cs,238Pu,239,240Pu,241Am,90Sr,totU) and radioactivity (gross a, ß, and γ), as a function of air emissions and fugitive dust, in surface soils (0–5 cm depth) collected from LANL, perimeter (PM) and background (BG) sites, and 2) determine if radionuclide concentrations are increasing or decreasing over time. Also, the total effective dose equivalent (TEDE) and the corresponding risk of excess cancer fatalities (RECF) to a PM community were estimated. Based on the long‐term average, nine out of the ten radionuclide parameters measured in LANL soils (n=12) were significantly (p<0.05) higher in concentration than BG (n=6). Perimeter soils (n=10), on the other hand, showed less differences with only four out of the ten parameters being statistically higher in concentration than BG. Most radionuclides in LANL and PM areas, with the exception of238Pu in soils from PM, significantly decrease in concentration over time, so that by 1996 most radionuclides were approaching values similar to BG. The maximum net positive TEDE (i.e., the TEDE + two sigma for each radioisotope minus background and then only the positive doses summed) for a resident living around the PM of LANL, as modeled by the residual radioactive (RESRAD) code using a residential scenario for soils collected from 1974–1996, 1993–1996, and in 1996 was 2.9 mrem y‐1(29 μSv y‐1), 2.3 mrem y‐1(23 μSv y‐1), and 0.8 mrem y‐1(8 μSv y‐1), respectively. All upper bound TEDEs were far below the International Commission of Radiological Protection permissible dose limit of 100 mrem y‐1(1000 μSv y‐1) for all pathways, and the highest TEDE corresponds to a RECF of 1.5 × 10‐6—an estimate far below the Environmental Protection Agency guideline of 10‐4.

ISSN:1093-4529    

DOI:10.1080/10934529809376731

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

This paper gives results of the measurements and evaluation of emissions from seven Swedish incineration plants. The investigated incinerators ranged from 12 to 80 MW, and include Martin grate, Von Roll grate, Overthrust (W+E) grate, Vereinige Kesselwerke (V+K) grate, travelling grate, vibration grate and circulating fluidized bed (CFB) types. The analytical techniques used include online carbon monoxide (CO), nitrogen oxides (NOX), sulfur dioxide (SO2), particulate matter (PM), carbon dioxide (CO2), combustion and flue gas temperatures, gas chromatography and mass spectrometry (GC/MS), using Tenax as adsorbent. A number of volatile organic compounds (VOCs) were identified and quantified. The effects of waste compositions, size of incinerators, air pollution control systems on the VOCs in flue gas were investigated. Overall combustion characteristics such as waste compositions, carbon monoxide incinerator output have been related to the emissions of total volatile organic compounds (TVOCs).

ISSN:1093-4529    

DOI:10.1080/10934529809376732

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Dry deposition and air sampling: were undertaken simultaneously in the ambient air of Ping Tung area by using several dry deposition plates, two MOUDIs (Micro‐orifice Uniform Deposit lmpactors) and one NRI (Noll Rotary Impactor) from December 1995 to May 1996 in Southern Taiwan. The NRI and MOUDI were used to collect ambient coarse and fine particulate, respectively. Dry deposition plate was applied to collect particle deposition flux. An ion chromatography (Dionex 2000i/SP) equipped with 4 mm AG4A‐SC and AS4A‐SC column was employed to analyze the anion species (NO, and SO42). The eluent solution is 1.8 mM sodium carbonate/ 1.7mM sodium bicarbonate. The calculated dry deposition flux for each particle size range was obtained by using measured mass‐size distribution data between 0.18 and 100 μm diameter and a dry deposition model. The mean modeled/measured (Md/ Ma) ratio of dry deposition flux varied between 1.11 and 1.28, between 1.28 and 1.42 and between 0.88 and 0.97 for nitrate, sulfate and total particle mass, respectively. The results indicated that nitrate and sulfate were slightly overestimated by a dry deposition model, while total particle mass was slightly underestimated by this model. In general, by using the particle size distribution data, this dry deposition model can provide a good predication for the dry deposition flux of nitrate, sulfate and total particle mass. More than 87.5 % of nitrate and more than 92.9%of sulfate dry deposition flux are contributed by particle diameters larger than 10 μm. This is due to the fact that particle size larger than 10 μm have higher dry deposition velocities (>4.65 cm/sec) and control the majority of the dry deposition flux.

ISSN:1093-4529    

DOI:10.1080/10934529809376733

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

ISSN:1093-4529    

DOI:10.1080/10934529809376724

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor