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Density functional theory (DFT) calculations were used to study the mechanism for the hydrochlorination of acetylene catalyzed by M[Cl.sub.x] (M = Hg, Au, Ru; x = 2, 3). For the three catalysts, the reaction occurs via a one-shift chlorine atom transfer, which avoids the formation of highly stable complex species. The adsorbed HCl acts as a chlorine donor, while the [C.sub.2][H.sub.2] favors the chlorine abstraction. The calculated real activation barrier decreases in the order: Hg[Cl.sub.2] > Au[Cl.sub.3] > Ru[Cl.sub.3], which suggests that the RuCl3 would be a good candidate catalyst for the hydrochlorination of acetylene. Key words: acetylene hydrochlorination, M[Cl.sub.x], reaction mechanism, DFT. On a fait appel a des calculs a base de la theorie de la fonctionnelle de la densite (TFD) pour etudier le mecanisme d'hydrochoruration de l'acetylene catalysee par les sels M[Cl.sub.x] (M = Hg, Au, Ru; x = 2, 3). Pour chacun de ces trois catalyseurs, la reaction se produit par le biais du transfert d'un atome de chlore qui permet d'eviter la formation d'especes complexes tres stables. Le HCl adsorbe agit comme donneur de chlore alors que le [C.sub.2][H.sub.2] favorise l'abstraction du chlore. La barriere reelle calculee pour l'activation diminue dans l'ordre Hg[Cl.sub.2] > Au[Cl.sub.3] > Ru[Cl.sub.3], ce qui suggere que le Ru[Cl.sub.3] serait un bon candidat pour catalyser l'hydrochloruration de l'acetylene. [Traduit par la Redaction] Mots-cles: hydrochloruration de l'acetylene, MClx, mecanisme de reaction, theorie de la fonctionnelle de la densite (TFD)., Introduction The hydrochlorination of acetylene is the process for the production of vinyl chloride monomer (VCM), which is one of the most important commodity chemicals. This is an important process [...]

A series of chlorinated polyethylene rubber (CM)/ethylene vinyl acetate (EVA) blends were prepared at different blending ratio. The blends were foamed by compression molding and azodicarbonamide (AZDC) was used as chemical blowing agent. Cure characteristics were researched first, and then the morphology and physical properties were investigated. It was found that neat CM foams presented a series of problems such as low hardness and high shrinkage ratio. To solve the above problems, some EVA was added into CM matrix. And the results indicated that these aforementioned defects were improved after the addition of EVA component. Tensile strength increased first and then fell, and morphology properties of CM/EVA blends were also investigated. POLYM. ENG. SCI., 52:218-224, 2012. © 2011 Society of Plastics Engineers, INTRODUCTION Many attractive properties such as light weight, buoyancy, cushioning performance, thermal and acoustic insulation, impact damping, and cost reduction make elastomeric foam to be widely used in three major [...]

The effect of conventional and booster chlorination on chlorine residuals and trihalomethane (THM) formation in drinking water distribution systems was modeled using the EPANET hydraulic modeling software. The model results suggest that booster chlorination may allow utilities to meet disinfection goals better by carrying chlorine residuals to remote points in the distribution system while lowering the total mass of chlorine applied to the system. The model results suggest that booster chlorination may provide the greatest advantages to points in the distribution system located near storage tanks by providing a more consistent chlorine residual and possibly reducing THM formation. A new version of the EPANET model, the EPANET Multispecies model, was also used to compare chlorine decay due to reactions in the bulk fluid and reactions occurring at the pipe wall. The results suggest that chlorine decay due to wall reactions can be very significant at remote points in the distribution system. Additionally, if THMs are assumed to form primarily through reactions in the bulk fluid, use of the new EPANET Multispecies software allows for calculation of THM formation based solely on chlorine reactions in the bulk fluid rather than on overall chlorine decay. DOI: 10.1061/(ASCE)0733-9372(2009)135:10(928) CE Database subject headings: Hydraulic models; Simulation models; Municipal water; Drinking water; Chlorination; Chlorine; Computer software.

An environmentally friendly method for producing chlorinated isotactic polypropylene (CIPP) with chlorine percentage of 28-35, by weight is proposed, in which a reactive solvent, paraffin, is used to replace the commonly used inert solvent of carbon tetrachloride (CTC), an ozone depleting substance being phased out under the Montreal Protocol. This method utilizes the principle that paraffin can dissolve isotactic polypropylene (IPP) at about 150°C and the resulting solution can be chlorinated concurrently, forming two useful products, viz. chlorinated paraffin (CP) and CIPP, which are mutually soluble even at lower temperature, e.g., 70°C. The present method is superior to the conventional CTC solvent method because it can reduce the solvent emission dramatically, enhance the volume efficiency of reactor, and achieve a unified production of CIPP and CP under atmospheric pressure. The structure and properties of CIPP produced by two different methods are determined by differential scanning calorimetry, attenuated total reflectance-Fourier transform infrared spectroscopy, proton magnetic resonance ([.sup.1]H-NMR), and [.sup.13]C-NMR. The results indicate that IPP chain can be homogeneously chlorinated in paraffin as in CTC solvent via a radical mechanism. POLYM. ENG. SCI., 49:1587-1593, 2009. [C] 2009 Society of Plastics Engineers, INTRODUCTION Chlorinated isotactic polypropylene (CIPP) with chlorine percentage of 28-35 by weight and random chlorine substitution in polymer has been widely used as adhesives of polypropylene materials (1-5). For such [...]

The impacts of bromide concentration and natural organic matter (NOM) characteristics on the formation and speciation of disinfection by-products (DBPs) in chlorinated NOM fractions were investigated. A total of 20 bulk water NOM fractions with a wide range of specific ultraviolet (UV) absorbance ([SUVA.sub.254]) values were obtained from a source water employing XAD-8 or XAD-4 resin adsorption in completely mixed batch reactors. SUVA was not a good predictor of DBP [trihalomethanes (THMs), haloacetic acids (HAAs), and adsorbable organic halogens (AOX)] formation and speciation. The destruction in the [UV.sub.254] absorbance from chlorination did not correlate with DBP formation at any bromide level. NOM moieties which do not absorb UV light at 254 nm significantly contributed to DBP formation. Mass balance calculations on halogens using THMs, HAAs, and AOX data indicated that significant amounts of DBPs (>54% of AOX) other than THMs and HAAs were formed in NOM fractions with 60-110 [micro]g/L bromide concentration. The relative occurrence of such other halogenated by-products decreased with increasing bromide concentrations up to 500 [micro]g/L level. NOM in the studied water was more susceptible to the formation of brominated THM species as opposed to brominated HAAs. At constant dissolved organic carbon concentration, chlorine dose and pH, increasing bromide concentrations in NOM fractions increased the total concentrations of DBPs and resulted in a shift toward the formation of brominated species. Further, increasing bromide concentrations increased the spectrum of detected species (i.e., occurrence of all nine HAAs) and provided a competitive advantage to THM and HAA precursors in NOM over precursors of other DBPs. DOI: 10.1061/(ASCE)0733-9372(2007)133:10(947) CE Database subject headings: Chlorination; Disinfection; Organic matter; Trihalomethanes.

Soils and decayed plant litter contain significant quantities of chlorinated aromatic polymers that have a natural but largely unknown origin. We used cupric oxide ligninolysis coupled with gas chromatography/mass spectrometry to show that Curvularia inaequalis, a widely distributed litter ascomycete, chlorinated the aromatic rings of lignin in wood that it was degrading. In aspen wood decayed for 24 weeks, two chlorolignin fragments, 5-chlorovanillin and 2-chlorosyringaldehyde, were each found at [approximately equal to] 10 [micro]g/g of wood (dry weight). These levels resemble those of similar structures generally found in unpolluted environmental samples. Fractionation of the extractable proteins followed by tandem mass spectrometric analysis showed that the colonized wood contained a previously described C. inaequalis chloroperoxidase that very likely catalyzed lignin chlorination. Chlorolignin produced by this route and humus derived from it are probably significant components of the global chlorine cycle because chloroperoxidase-producing fungi are ubiquitous in decaying lignocellulose and lignin is the earth's most abundant aromatic substance. chloroperoxidase | humus | hypochlorous acid | Pleosporales | soil

A multirun analytical method has been developed and validated for trace determination of 24 antibiotics including 7 sulfonamides, 3 macrolides, 7 quinolones, 6 tetracyclines, and trimethoprim in chlorine-disinfected drinking water using a single solid-phase extraction method coupled to liquid chromatography with positive electrospray tandem mass spectrometry detection. The analytes were extracted by a hydrophilic-lipophilic balanced resin and eluted with acidified methanol (0.1% formic acid), resulting in analyte recoveries generally above 90%. The limits of quantitation were mostly below 10 ng/L in drinking water. Since the concentrated sample matrix typically caused ion suppression during electrospray ionization, the method of standard addition was used for quantitation. Chlorine residuals in drinking water can react with some antibiotics, but ascorbic acid was found to be an effective chlorine quenching agent without affecting the analysis and stability of the antibiotics in water. A preliminary occurrence study using this method revealed the presence of some antibiotics in drinking waters, including sulfamethoxazole (3.0-3.4 ng/L), macrolides (1.4-4.9 ng/L), and quinolones (1.2-4.0 ng/L).

Studies were conducted to determine if radiation and chlorine acted in a simple additive process or in a nonadditive increase in inactivation when chlorination occurred after gamma-irradiation of Salmonella, Escherichia coli O157: H7 and Listeria monocytogenes cells. Results revealed that gamma-irradiation and chlorination of the samples acted synergistically producing a greater-than-additive inactivation, the effects seen to occur during the inactivation of Salmonella contaminating alfalfa seeds.

Transient flavin intermediates in the flavin-dependent halogenase RebH reaction catalyzing chlorination are characterized and the kinetics of 7-chlorotryptophan formation is determined. The kinetic analysis establishes that substrate chlorination occurs after completion of flavin redox reactions, consistent with a mechanism whereby hypochlorite is generated in the RebH active site from the reaction of FaD[H.sub.2], chloride ion and [O.sub.2].

The mechanism of chlorination of the 2,2,5,5-tetramehylimidazolidin-4-one (TMIO) with hypochlorous acid and N-chlorosuccinimide (NCS) is investigated both in the gas and solution phases. The hypochlorous acid as a chlorinating agent has showed that solvation plays an important role in the reaction energetics and the solvation has altered the kinetic and thermodynamic preferences of the reaction outcome.

Bacterial community dynamics of a whole drinking water supply system (DWSS) were studied from source to tap for which raw water was provided by two reservoirs with different water characteristics in the Harz Mountains of Northern Germany. It showed significant differences in the detection of the major taxonomic groups between DNA-based and RNA-based fingerprints irrespective of the reservoir and chlorination of the drinking water seemed to promote growth of nitrifying bacteria.

Treatment of 1,2-bis(ethynyl)benzene (1) with aqueous HX (X=Br, I) in hot 3-pentanone afforded 1,2-bis(1'-haloethenyl)benzene species 2-Br and 2-I in 98% and 95% yields, respectively. The hydrochlorination of endiyne 1 failed to proceed at elevated temperature but is implemented efficiently by PtCl(sub 2) in hot 3-pentanone to give 1,2-bis(1'-chloroethenyl)benzene 2-Cl in 80% yield.

The failure of sludge chlorination to prevent filamentous bulking in wastewater treatment plants may occur because the microbial community in the sludge is resistant to chlorine. Researchers describe two filamentous bacteria that cause bulking in wastewater, one of which is sensitive to chlorine and one of which is resistant.

The reaction rate coefficients, themochemistry and mechanism applicable to the addition of a chlorine atom to allene have been studied by using cavity ring-down spectroscopy and ab initio calculations.

Water-suppressed NMR is used to study the interaction of acetylated amino acids and peptides with aqueous chlorine near neutral pH.

Experiments have been conducted concerning the mechanism that governs the addition reactions of chlorine and bromine atoms with propargyl halides. Ultraviolet spectra of radical adducts C (sub)3 H (sub)3 Cl (sub)2, C (sub)3 H (sub)3 ClBr and C (sub)3 H (sub)3 Br (sub)2 have been observed.

Efficient dechlorination occurs with ultraviolet photolysis of TiO2 nanocrystallite layers in contact with aqueous solutions containing both CCl4 and methanol. It has been possible to achieve quantum yields much higher than one for the first time.

The combination of gas chromatography (GC) and laser-based resonance-enhanced multiphoton ionization-time-of-flight mass spectrometry (REMPI-TOFMS) represents a three-dimensional analytical method, using the gas chromatographic retention time, the wavelength of the ionization laser for REMPI, and the molecular mass as analytical parameters. In this work, a novel analytical scheme for detection of chlorinated aromatic compounds, including isomeric ensembles, by GC/REMPI-TOFMS is presented. The concept uses an in-line hydrodechlorination catalyst for post- or precolumn derivatization of chlorinated aromatic compounds. The chlorinated aromatics are quantitatively reduced, forming their respective aromatic skeletons. These aromatic skeletons are detected selectively by REMPI-TOFMS. The first results for substance class selective detection of chlorinated benzene isomers are given, and potential applications in the field of the analysis of compounds such as polychlorinated dibenzo-p-dioxins and furans are discussed.

Research was conducted to examine bacterial growth state in municipal effluent during wastewater disinfection. A novel immunofluorescence assay was developed and utilized for the study while eterobacterium-specific antibody fluorochrome-coupled probes were used to determine quantitative levels of three highly conserved cytosolic proteins. Results suggest that the current standard procedures for wastewater analysis, which depend on detection of culturable cells likely underestimate fecal coliform content.

Sealed-tube reactions or the introduction of an electron-donating group into the carborane cage provided a synthetic pathway to highly chlorinated, brominated and iodinated icosahedral carborane anions. The novel sealed-tube method can compel the halogenation reactions of the parent carborane anion CB(sub 11)H(sub 12)(super -) to proceed to completion while reducing the reaction time and increasing the reaction yield. This new approach can be applied to other carboranes or polyhedral boron clusters.

Thermal and visible light-induced reaction of benzene-Cl2 gas mixtures loaded into zeolite NaZSM-5 was investigated. Results show that 1,4-dichlorobenzene is formed as the sole dichloro product when loading the reactant gas mixture into zeolite NaZSM-5 at -100 degrees C, a selectivity that is unprecedented. No other products aside from chlorinated benzenes are observed even at elevated temperatures or high conversion. Irradiation of 1,4-dichlorobenzene with green or blue light yielded 1,2,4-trichlorobenzene as the only product at high conversion.

A study investigates the conditions of formation of organoiodinated compounds responsible of medicinal tastes and odors often observed after chlorination of waters containing iodides. Results reveal that ammonia or organic amines contribute in iodorm formation during chlorination of iodides containing waters at amine ratios corresponding to the presence of inorganic or organic chloramines. Nitrogenated molecules such as amines and amino acids, however, have limited role in the production of organoiodinated compounds during chlorination.

A study was conducted to evaluate the efficiency of a one-pot system that can catalytically dehalogenate highly-chlorinated aroclors and benzenes at reasonable conversion rates. The system utilizes THF as solvent, PdCl2(dppf) as catalyst, NaBH4 as reducing agent and TMEDA as a supporting base. Results on dechlorination efficiency and regioselectivity were considered satisfactory.

The presence of natural organic matter in drinking water reservoirs was found to be significant in monocholoramine decomposition, reducing the potency of the disinfection process. Natural organic matter was found to act as a reducing agent, where monochloramine is decomposed to yield higher concentrations of atmospheric nitrogen and NO3-. This decomposition process was validated both by mass and redox balance, where the oxidized product production equates with monochloramine loss.

Research was conducted to examine the low-temperature chlorination of GaAs(100). Soft X-ray photoelectron spectroscopy, which employs syhnchrotron radiation, was used to investigate the chemisorption and the reaction of chlorine and hydrogen chloride on the GaAs surface at 110 K. Results provide an insight into the reaction mechanism of the synchrotron radiation-induced etching of the GaAs surface by Cl2 at low temperatures.

The physiological properties of a mixed culture which effectively dechlorinates trichlorobenzenes were investigated as well as the effects of various specific inhibitors and alternative electron acceptors. In situ probing revealed that two major subpopulations within the microbial consortium were phylogenetically affiliated with a sublineage within the Desulfovibrionaceae and Proteobacteria. Sulfate strongly inhibited the dechlorination of trichlorobenzenes. Molybdate at a concentration of 1mM also inhibited the dechlorination of trichlorobenzenes.

A research was conducted study the role of methanogenic archaea to tetrachloroethene dechlorination. 16S rDNA targeted primers were utilized to confirm the absence of methanogenic arachaea while samples were beaten at 5,000 beats per minute in a Mini-Beadbeater. Enrichment cultures produced bacterial 16S rDNA polymerase chain reaction products. Results indicated that 2-Bromoethanesulfonate was a potent inhibitor of methanogenic archaea, although its action was not as specific as previously believed.

A research was conducted to examine the effects of chlorinated ethene transformations on the cell viability of Methylosinus trichosporium OR3b. Culture viability decreased exponentially with the amount of substrate converted. The ratios were greater than one in chlorinated ethenes indicating cell death was the predominant toxic effect. Results indicated that the cell viability was affected via a diffusible oxidation product after the rate of killing was proportional to the number of present viable cells.

Research was conducted to study the substrate specificities of two anaerobic polychlorinated biphenyl (PCB)-dehalogenating enrichments that showed different para-dechlorination specificities. PCBs were extracted by anhydrous diethyl ether and determined with a gas chromatograph. The enriched cultures showed a high degree of specificity for few PCB congeners. Moreover, the addition of both the priming congener 2346-CB and the 2346-CB enrichment did not simulate Aroclor residue dechlorination.

The Surface Water Treatment Rule under the Safe Drinking Water Act and its amendments require that the water utilities maintain a detectable disinfectant residual throughout the distribution system at all times. A new computer model is presented to directly calculate the chlorine concentrations needed at the source(s) to have specified residuals at given locations in a pipe network in unsteady flow conditions by using an inverse method. Unlike the forward solution method, which calculates the source chlorine concentration by a trial-and-error procedure, the inverse solution technique presented in this paper directly calculates the source concentration required to meet a specified value at a particular point in the network. The dynamic flows and pressures are first calculated by solving the governing equations by an implicit finite-difference scheme subject to appropriate boundary conditions. For chlorine concentrations at various pipe sections and at each node, the one-dimensional transport equation is modified for the advection dominated flow. This modified transport equation is then discretized by using the four-point implicit finite-difference scheme and solved simultaneously together with the junction mass balance equations. A first-order reaction rate for chlorine decay is assumed and a flow-weighted averaging procedure is used to calculate the complete mixing of chlorine at the junctions. For the verification of the inverse method, the computed results are compared with those determined by direct simulations. An excellent agreement is observed between the inverse method and direct simulation technique.

The chlorination of the amino acid lysine resulted in the formation of a number of complex byproducts due to the effect of reactive side chains, and this observation has implications in the measurement of wastewater disinfection treatment. The chlorination of lysine produced the expected products, which include n-chloramino acid and n-chloroaldimine, but the process also created also created byproducts which interfere with the use of iodimetric methods of measuring the bactericidal potential of wastewater.

The zinc chloride-mediated acetylation of the optically active silyl enol ether produced the beta-diketone (48%) together with the regio- and stereoselectively chlorinated compound (27%). The yield of the chlorinated compound rose to 70% by beginning from the O-acetyl derivative. There is a great possibility that the chlorination was caused by neighboring group participation by the endo acetoxy group.

The chlorination of resorcinol through dichlororesorcinol was evaluated using a series of chlorine-substituted resorcinol substrates. Their initial chlorination kinetics were examined over the pH range of two to 12 at 12 degrees Celsius. The apparent chlorination rates for each of the resorcinol substrates are a minimum in the pH range of three to six and a maximum in the pH range of eight to 11. A mechanism involving the reaction of HOCl with ArX(OH)2, ArX(OH)O- and ArX(O-)2 and an acid-catalyzed pathway at pH

Meta-dechlorination inhibits the complete reductive dechlorination of di- and trichlorobenzoates in sediment slurries. This was observed in a comparison of the sequence of reductive dechlorination for several chlorinated benzoates in unacclimated and acclimated anoxic sediment slurries. The comparison aimed to establish complete dechlorination of polychlorinated benzoates by inducing a specific sequence of reductive chlorine removal. Potential factors affecting the occurrence of ortho- or meta-dechlorinating microbial activities were examined.

Chlorophenols (CPs) can be classified into two groups, namely, those transformed exclusively by dechlorination and those transformed mainly through non-dechlorination pathway(s). This was gleaned from the results of an examination of the kinetics and pathways of chlorophenol transformations in an anaerobic estuarine sediment collected from the mouth of Japan's Tsurumi River and the contribution of different transformation pathways. A pathway-dependent first-order dechlorination rate constant was calculated from the contribution of each pathway, which indicated a preferential o-chlorine removal compared to m- and p-chlorine.

A study was conducted on the reactions of dibenzofuran and 1,2,3,4,7,8-hexachlorodibenzo-p-dioxin on fly ash found in municipal incinerators. Simultaneous chlorination and dechlorination were measured by using a hexachlorodibenzodioxin. The chlorination of dibenzofuran was found to produce all possible polychlorinated dibenzofuran cogeners. The chlorination reaction was found to be based on an electrophilic aromatic substitution mechanism.

Polychlorinated biphenyls (PCBs) carried popular applications in heat-transfer settings due to their outstanding stability and thermal properties. A substantial fraction of PCBs remain in the environment due to their persistence, a problem which has become a vital concern of environmentalists. PCB mixtures lose their chlorinated congener status when undergoing hydrogenolytic dechlorination.

The recovery of chlorobenzenes (di- to hexachloro) and hexachlorocyclohexane (HCH) isomers from supercritical carbon dioxide by trapping in cold solvent was studied. By changes in supercritical pressure, flow rate, nature and temperature of the solvent, and trap geometry, recoveries of chlorobenzenes varied in the range 80-100%, and those of HCH in the range 50-94%. For the optimum set of variables, the average recovery of all compounds was 95%. With these trapping conditions, an environmental soil sample gave average supercritical fluid extraction (SFE) recoveries (compared to Soxhlet extraction) of 60-85%, depending on the SFE conditions.

Low-temperature NMR studies of the reaction between cephalosporin or carbacephalosporin enols and (PhO)3P(+)ClCl(-) reveal the formation of an intermediate enol phosphonium species. 31P NMR study helps determine rate constants and Arrhenius activation energies for both reactions. Cephalosporin enol reaction exhibits a lower activation energy than carbacephalosporin enols. This decrease is due to sulfur neighboring group participation. A mechanistic study shows that both reactions involve fast chloride addition to an intermediate, followed by rate-determining phosphate departure.

A new anaerobic biofilm reactor was tested via experiments on the microbial dechlorination of chloroaliphatics. The reactor is enriched with a solution that contains desulfomonile tiedjei DCB-1, a catalyst for the reductive dechloronization of 3-CB, PCE and pentachlorophenol. The results, which reveal the absence of vinyl chloride in the dechlorinated water, show its efficacy in dechlorinating PCE, chloroform and 1,1,2-trichloroethane.

The microbial dechlorination of chlorinated benzenes are investigated via the use of an anaerobic culture procured from a Lake Ketelmeer sediment where in situ dechlorination has taken place. The culture, which is enriched with hexachlorobenzene and lactate, was used to study the compound selectivity, rates and temperature effect on dechlorination in a methanogenic environment. The results revealed the occurence of only seven reactions out of 19 possible biodegradation reactions.

The acclimation time and order of chlorine removal from the phenyl rings of polychlorinated biphenyls were observed in a study on microbial reductive dechlorination. The experiment investigated six trichlorobiphenyls in sediment slurries of the Hudson River, Silver Lake and Woods Pond. The results, which suggest the feasibility of using microbial degradation of polychlorinated biphenyls for decontamination, showed similar acclimation times of three weeks.

The chemical reaction between aqueous chlorine and orcinol and other humic acids were investigated via gas chromatography-mass spectrometry at chlorine to substrate molar ratios ranging from 1:2 to 4:1 and neutral pHs. The experiment, which resulted in more oxidized products at longer reaction times, produced over 40 products and intermediates. These includes noncyclic and cyclic chlorinated ketones, carbonic acids, ketoacids, lactones, chlorinated orcinols and furanones.

Photochemical studies of UV-irradiated solution phase azulene prove that azulene solutions undergo deuteration and chlorination in the presence of light. A single proton catalyzes the substitution reaction at a threshold of 27956 per centimeter. Deuteration and chlorination reactions involve the replacement of protons at two similar regions in azulene's smaller ring.

The oxychlorination of phenol in the presence of HCl catalyzed by fly ash yielded chlorinated phenols. These chlorinated phenols were condensed into CO2 and polychlorinated dibenzo-p-dioxins (PCDD) at temperatures above 625 degrees K. This codensation was found to result from the catalytic activity of metal sites. Higher concentrations of HCl increased rates of oxychlorination, while increasing the possibility for the formation of PCDD/furans.

The synthesis of hydroxyfuranones with a dichloromethyl, monochloromethyl or methyl group joined to the carbon at the 4-position in the furanone ring and with a chlorine or hydrogen atom attached to the carbon at the 3-position was undertaken. These compounds were quantitatively determined in chlorination-stage bleaching liquors and in extracts of chlorinated fulvic acids, chlorinated humic water and chlorine-purified drinking water. The compounds were found to induce mutagenicity in the Ames tester strain TA100.

An investigation was conducted to isolate polychlorinated dibenzofurans (PCDFs), polychlorinated dibenzo-p-dioxins (PCDDs) and their possible precursors in samples from catalytic reforming process and reactions within a flow tube reactor. The results showed the presence of a large number of aromatic hydrocarbons which could act as PCDD and PCDF precursors. In addition, a possible de novo pathway for PCDF formation from chlorinated hydrocarbons was found.

The chlorination of the amino acid phenylalanine in water and wastewater is discussed. Volatile chlorinated products were determined by gas chromatography/mass spectrometry analysis of ether extracts of chlorinated phenylalanine reaction mixtures. High performance liquid chromatography with ulatraviolet detection chlorinated and analyzed model solutions of phenylalanine. Major differences in the distribution of organic and inorganic chloramines and in the product distribution betwen the model solutions and the wastewater was determined.