Russell F. Christman

Structural characterization of aquatic humic material. 2. Phenolic content and its relationship to chlorination mechanism in an isolated aquatic fulvic acid.

The complementary techniques of solid-state /sup 13/C nuclear magnetic resonance spectroscopy and chemical degradation were utilized to examine the lignin/phenolic substructure of an isolated aquatic fulvic acid capable of producing upon aqueous chlorination a number of organohalides typically found in municipal drinking water. Results indicate that while phenolic moieties are present in the fulvic acid, they account for only a minor fraction of the total carbon. A sequential chemical degradation experiment utilizing aqueous chlorine and CuO demonstrated that the lignin/phenolic substructure was attacked by the chlorine. It is concluded that while phenolic ring rupture mechanisms appear to be important in organohalide generation, other aqueous chlorination mechanisms involving aliphatic and other types of aromatic structures should also be considered. 35 references, 12 figures, 3 tables.

Extent of ozone's reaction with isolated aquatic fulvic acid

Samples of North Carolina aquatic fulvic acid were ozonated in a neutral buffer at several ozone/carbon ratios, and the reaction mixtures were characterized by using total organic carbon (TOC) and UV-visible absorbance analysis, XAD-8 chromatography, and ultrafiltration. Results show a large initial ozone consumption with loss of TOC and UV-visible absorbance by the fulvic acid solution followed by a slower rate of ozone consumption and decrease in TOC and UV-visible absorbance at higher doses. Exclusion chromatography and ultrafiltration show an increase in smaller sized materials. The authors conclude that ozone initially and rapidly attacks sensitive nucleophlic sites on the molecule. At higher doses slower cleavage reactions produce structural changes in the macromolecule. 15 references, 8 figures.

Impact of imposed anaerobic conditions and microbial activity on aqueous-phase solubility of polycyclic aromatic hydrocarbons from soil

The influence of anaerobic conditions on aqueous-phase polycyclic aromatic hydrocarbon (PAH) bioavailability was investigated in laboratory microcosms. Highly aged (>70 years), PAH-contaminated soil was incubated under anaerobic conditions by using various anaerobic headspaces, anaerobic headspaces with an oxygen-scavenging complex (titanium(III) citrate) in the aqueous phase, or anaerobic headspaces with electron-acceptor amendments in the aqueous phase. Incubation of soil solely under anaerobic conditions resulted in increased aqueous concentrations of all PAHs tested (fluoranthene, pyrene, benz[a]anthracene, and benzo[a]pyrene). Benz[a]anthracene and benzo[a]pyrene extractable concentrations were above aqueous solubility, by as much as an order of magnitude for the latter. The degree of solubility increase observed was a function of molecular weight of the PAH regardless of initial soil concentration, suggesting formation of stable PAH-soluble organic matter associations. The soil samples incubated aerobically for 90 d before imposition of anaerobic conditions did not release PAHs to the aqueous phase. Methanogenic organisms and sulfate-reducing bacteria were seen to have the most significant effect on increases in aqueous-phase PAHs. Polycyclic aromatic hydrocarbons made more soluble under anaerobic conditions was available to be degraded or transformed under aerobic conditions.

The reaction of ozone with isolated aquatic fulvic acid

Abstract Aquatic fulvic acid, isolated from a North Carolina bay lake, was reacted with ozone, an alternative oxidant in drinking water treatment. Ozonated samples were acidified, extracted with ether, dried, concentrated, and methylated prior to GC-MS analysis. Identified reaation products include mono-, di- and tribasic aliphatic acids and benzene tricarboxylic acids. The products with the highest relative concentrations were succinic and malonic acid, although all products were at relatively low concentration levels. Many of the products identified in this study have also been seen among the reaction products of fulvic acid and other oxidants, such as Cl 2 , CIO 2 and KMnO 4 .

Effect of monochloramine on isolated fulvic acid

Abstract Monochloramine is interesting both as a selective oxidant of fulvic acid and as a drinking water disinfectant. In this study, the controlled reaction of aquatic fulvic acid with monochloramine did not result in products detectable by ether extraction-gas chromatography-flame ionization detection techniques. Evidence of a reaction was shown by bleaching of the fulvic acid solution (decreased absorbance at 465 nm) and chlorine substitution. Chlorine-containing products were quantified by the total carbon adsorbable organic halide (TOX) parameter. Bleaching and organic chlorine formation were much less extensive than in the reaction of free chlorine with fulvic acid. Monochloramine was shown to produce an organic chlorine fraction more hydrophilic and with higher molecular size than that produced by chlorine and fulvic acid. Results suggest that monochloramine may be useful tool for the investigation of certain humic functionalities because it reacts rather selectively and to a small extent with aquatic fulvic acid.

Quantifizierung organischer substanzen in Aktivkohleextrakten mit Hilfe der Gas-Chromatographie/Massenspektrometrie

SummaryUse of activated carbon plays a significant role in water technology and analytical chemistry. Therefore determination of substances adsorbed on activated carbon is of special interest. As an example, granulated activated carbon (GAC) from a water treatment plant was serially extracted with different organic solvents. Quantitative determination of some selected compounds in the combined extracts was done by gas chromatography/mass spectrometry. The method of internal standard addition and calibration by response factors was used. The determined compounds (all of substituted benzene type) were extracted from the GAC in the concentration range from 0.2 mg/100 g (m-dichlorobenzene) to 5 mg/100 g (nitrobenzene). Relative standard deviation for double determination of five independent samples from the GAC filter was less than ±20%Spike experiments were performed to determine recovery efficiences. As expected, substance specific differences appeared and the recoveries were between 36% (m-dichlorobenzene) and 80% (nitrobenzene). A significant limitation for quantitative determination results from lack of available substances for calibration.

Editorial. training needs.

The decision of the Office of Management and Budget to phase out federal support of university graduate training programs rests on two beliefs: (a) that substantial progress has already been made with the establishment of professional programs at universities from earlier federal investment-and universities should guarantee their continuation; and (b) that market forces are currently the best means of fulfilling manpower needs, as present salaries in the environmental field are sufficiently competitive to attract graduates from traditional science and engineering programs. EPA, OMB, and university program advocates agree that because of the stimulus of recent federal legislation, the demand for large numbers of trained personnel will continue. The magnitude of this demand has been estimated at 5000 new specialist professionals per year for the water and air pollution control fields alone. The federal position is misguided in several ways. First, it is not the primary responsibility of universities in this country to meet short-term national need. Rather, that function belongs to government and it is properly discharged through the use of federal research and training resources as incentives to university productivity. Second, an unfortunate corollary of the federal emphasis on the market process is that no special training is required for entrance into the environmental field. Since the phase-out decision was reached in 1973, a series of individuals and professional organizations have advised EPA and OMB that the consequences would likely be felt first in the form of decreased enrollment. This prediction has been realized as the current new MS-level enrollments in pollution control programs are approximately one-fifth of the 1973 levels. OMBs response to this observation has been to point out that the decline in non-subsidized enrollments has exceeded the decrease in subsidized enrollments; an incredible denial of the original program objective of stimulating total enrollment through partial federal subsidy. Our federal policymakers are disregarding a paradox of their own creation; an increasing demand for professionals, coupled with increasing public expenditures for pollution control programs, and decreasing supplies of trained environmental engineers and scientists.

Editorial. Earth day revisited.

It is said that today is the age of environmental realism in the U.S. The evangelism of the 1970 movement for environmental reform has subsided and in its wake lie increased awareness of pollution and a growing sense that contamination at some level and some price is an unavoidable consequence of an industrial society. We have told ourselves that we can clean up if we want to (we got to the moon, didn’t we?), and a certain caution about overregulation has settled in-clean up so long as we don’t lose things of “real” value such as energy supplies, new commodities, and industrial growth. Even the Club of Rome is softening its gloomy global predictions. Have we buried our heads in the sand and ignored the heart of the issues raised so vociferously six or seven years ago? We must admit that we haven’t seriously examined our dependence on growth and consumption as the basis of our life style. We have, instead, attempted through complex, burdensome, and costly legislation to clean up the effluvia resulting from our seemingly insatiable material appetites. We have tinkered with only one end of the pipe in cleaning our water and air. In fact, the cleanup has even been justified by the growth stimulation it has provided to the new pollution control industry. The Ehrlichs, Commoners, Carsons, and Udalls were not talking so much about dirty water and air as they were about the consumptive attitudes that created them. Can the whole world live the way we do? They cannot be blamed for wanting to, and the moral basis for our foreign policy demands that we assist them in reaching this goal. If they cannot, how will we explain to them that they should continue to supply us with the raw materials for our comfort? How long will we be able to export food to pay for resources we cannot produce ourselves? How long will our influence last in the face of these unanswered questions? President-elect Carter has promised us a national energy policy. This is long overdue and should entail deep and serious social as well as technical deliberations. Let’s hope that it will be based upon a philosophical recognition that material growth is not inherently good, and that the quality of life for each of us means much, much more than clean water and breathable air.