Dehalogenation and decolorization of wheat strawbased bleachery effluents by Penicillium camemberti

This paper examined the capability of Penicillium camemberti to dechlorinate and decolorize wheat straw-based pulping and bleaching effluents. In batch tests, the highest removals for CEH (Chlorination-Extraction-Hypochlorite) bleaching sequence [65% organic halides (AOX) 84% color] were obtained with 2 g/l acetate concentration in 10 days under non-shaking conditions. Experiments in shaking flasks containing Tween 80 produced 60% AOX, 79% color removals in 10 days. This removal efficiency was also in accord with gas chromatography analysis indicating drastic reductions at low molecular weight adsorbable organic halogen compounds

Fungal treatment of hemp-based pulp and paper mill wastes

This paper examined the ability of Penicillium camemberti to degrade hemp-based pulp and paper plant bleachery effluents in batch and up-flow column reactor studies. In batch tests, the highest removalsfor acid-line effluents (67% AOX (adsorbable organic halogens), 44% TOC 8 total organic carbon), 97% color) were obtained with 2 g/l acetate concentration in 10 days. Acid-line and alkali-line composite effluent was also fed to a column reactor with of 17 mg/l. AOX concentration. In column studies, the highest removals (57% AOX, 67% TOC, and 74% color) and (57% AOX, 48% TOC and 73% color) were obtained with 0.5 and 0.2 g/l feed acetate concentration in 20 days, respectively. Gas chromatographyanalysis indicated drastic reductions at low molecular weight adsorbable organic halogen compounds

Treatment of softwood bleacbery effluents by Penicillium camemberti in anaerobic jars

Penicillium camemberti was found to be very effective in treating softwood pulp bleaching effluents and chlorinated model compounds like PCP, 2-chlorophenol and trichloroacetic acid. This paper examines the ability of Penicillium camemberti to degrade softwood pulping and bleaching effluents in anaerobic jars. Softwood chlorinated pulping and bleaching effluents inoculated with Penicillium camemberti (20 ml in 25-ml universal tubes) were incubated under anaerobic conditions (oxoid anaerobic jars) at 25 degrees C for up to 20 days. Samples were analyzed for adsorbable organic halogens (AOX), color and total organic carbon (TOC) removals and gas chromatograms of the samples were recorded. 61% AOX, 62% TOC and 57% color removal was obtained with mineral salts as nutrient and 2 g/l acetate as carbon source. It was found to be remarkable that TOC removal was extremely increased from 62% to 81% with the nutrient only, and without any carbon source. There was a slight increase in AOX (from 61% to 63%) and slight one in color (from 57% to 52%). The highest efficiencies, 62% AOX, 81% TOC and 59% color removal, were achieved, when Penicillium camemberti has been added without any nutrient and carbon source

Developing fungal reactor for organic chlorine removal from pulping effluents

Organic halides are considered environmentally suspect as some are known to have toxic, mutagenic and carcinogenic effects on the biota. A fungus, which is able to affect close to 60 % AOX, colour and TOC removals from softwood bleachery effluents in batch tests have been isolated and tentatively identified. This fungus was subsequently tested for its ability to degrade PCP, a common preservative used in controlling wood rot. Low agitation speeds preferred by the fungus during batch culturing indicated its tendency towards immobilization on a solid matrix. A continuous upflow packed bed reactor was designed and operated successfully in our laboratory for over one and half year with somewhat higher performances over those obtained in batch tests. Around 80% AOX and 60% colour and TOC removals were observed in this packed-bed reactor treating effluents from a softwood pulp bleachery. The PCP removals, which were tested separately, were also comparable to the AOX removals

Identification of electron acceptor properties of Penicillium camemberti used for effective treatment of chlorinated organic compounds

Two methods described in this paper use respirometric monitoring of the accumulated oxygen uptake rate, following the addition of bleachery effluents to a reactor containing Penicillium camemberti and detection of inorganic chloride removal by a chloride electrode for electron acceptor identification. In the case of respirometric studies, adsorbable organic halogens (AOX) removal was retarded at high acetate concentrations and the metabolism shifted towards aerobic respiration. Contrary to this, aerobic respiration was suppressed at low acetate concentrations and the removal of AOX was enhanced. Inorganic chloride removal detected with a chloride electrode verified these findings too. Cl- ion production paralleling AOX removal supports the hypothesis that organic chlorine acts as electron acceptor for this fungus

Biological treatment of paper pulping effluents by using a fungal reactor

Pulp and paper plants are amongst the most polluter industries in this country and elsewhere. Most of the organic halides (AOX) and colour from pulp bleaching units are discharged to the receiving basins without being fully treated. A fungus, which is able to affect over 50% AOX and colour removals from soft-wood bleachery effluents within two days contact time, have been isolated in this laboratory. Optimum condition for dechlorination by this fungus in batch tests was determined as pH 5.5 and 25 degrees C. The low agitation speeds required by the fungus indicated its tendency towards immobilisation on a solid substrate. Glass wool was chosen as a suitable immobilising matrix to be used in the continuous experiments. An up-flow column was packed with glass wool and operated successfully for over one and half years with AOX removals around 70% in 7-8 hours contact time. Fungal dehalogenation required very low supplemental carbon and no DO. The fungal reactor was also effective in dechlorinating polychlorinated aromatics, e.g. PCP, though dehalogenation ability decreased considerably with the chlorinated aliphatics. High PCP concentrations presumably toxified the fungus, even at short exposures, thereby irreversibly damaging the column reactor. (C) 1999 Published by Elsevier Science Ltd on behalf of the IAWQ. All rights reserved

Biological treatability of pulping effluents by using a Penicillium species

Pulp and paper plants are among the most polluter industries. Their effluents are normally treated biologically for standard parameters such as BOD and GOD; but biological treatment is usually not complete. Unconventional parameters unique to these wastes, such as color and organic halides(AOX), are virtually persistent throughout the treatment cycle. A fungus, which is able to affect over 50% AOX and color removal from soft wood pulping bleachery effluents in less than two days of contact, have been isolated and tentatively identified as Penicillum sp

Degradation of chlorinated compounds by Penicillium camemberti in batch and up-flow column reactors

A Penicillium camemberti strain isolated in this laboratory was studied for its ability to degrade chlorinated compounds including pentachlorophenol (PCP), 2-chlorophenol and trichloroacetic acid. The batch experiments were conducted in shake flasks using PCP as co-substrate resulting in around 56% PCP removal by the fungus. Experiments in shake flasks not containing acetate but Tween 80, produced 86% of PCP and 53% of 2-chlorophenol removals in 21 days. PCP was also fed to a column reactor with an adsorbable organic halogens (AOX) concentration of 63.4 mg/l. On the fourth day of operation, AOX removal was 77%, but this steadily dropped to 18.8% on the 18th day

Upflow column reactor design for dechlorination of chlorinated pulping wastes by Penicillium camemberti

A Penicillium camemberti strain isolated in our laboratory has been studied for its ability to degrade chlorinated pulping wastes, presumably containing a variety of chlorinated polyphenols. In batch tests, the highest removals (76% AOX, 61% color and 65% TOC) were obtained with 0.2 g/l feed acetate concentration. The tendency of the fungus to dechlorinate bleachery effluents better under non-shaking conditions and to attach onto surfaces suggested the use of immobilized cells rather than freely suspended ones in further exploitation of the process. An upflow glass wool packed column reactor established with this fungus could be operated for nearly two years in the laboratory. At best around 70% AOX could be removed from chlorinated pulping wastes in 7.3 h of contact with no aeration and with a minimal amount of carbon supplement (0.2 g/l). Finally, an asymptotic mathematical formula for determining Michaelis-Menten kinetic rates has been derived. The kinetic rates Km (the Michaelis constant or saturation constant for the substrate) and V-m (the product of maximum rate for the enzymatic reaction and biomass concentration) were then calculated as 126.386 mg/l and 2.83017 mg/l h, respectively. (C) 2004 Elsevier Ltd. All rights reserved