Peracetic acid as an alternative wastewater disinfectant to chlorine dioxide

AIMS: The aim of this study was to compare the efficiency of peracetic acid with that of chlorine dioxide in the disinfection of wastewater from a sewage treatment plant (serving about 650 000 inhabitants) that has been using peracetic acid as a disinfectant since 1998. METHODS AND RESULTS: A total of 23 samplings were made, each consisting of three samples: from secondary effluent, effluent disinfected with 2 mg l(-1) of peracetic acid and effluent disinfected with 2.2 mg l(-1) of chlorine dioxide (contact time 20 min). For each sample, measurements were made of the heterotrophic plate count at 36 degrees C, total and faecal coliforms, Escherichia coli, enterococci, pH, suspended solids and chemical oxygen demand (COD). During the first phase of the experiment the peracetic acid was seen to be less efficient than chlorine dioxide. To improve the disinfectant action a system of mechanical agitation was added which led to a greater efficiency in the inactivation of bacteria of faecal origin. CONCLUSIONS: Both products were found to be influenced by the level of microbial contamination, the amount of suspended solids and COD but not by the pH of the effluent before disinfection. The immediate mixing of the wastewater and disinfectant caused a greater reduction in enterococci. SIGNIFICANCE AND IMPACT OF THE STUDY: Since peracetic acid was seen to produce a high abatement of micro-organisms, it can be considered as a valid alternative to chlorine dioxide in the disinfection of wastewaters.     

The combined effects of various disinfectants against poliovirus 1 in a municipal wastewater effluent

Abstract The effects of the combination of any two of the following disinfectants: chlorine, chlorine dioxide, ozone and peracetic acid were investigated using poliovirus 1 as a model virus in a municipal sewage effluent. It was noted that the efficacy of chlorine was enhanced in the presence of either chlorine dioxide, ozone or peracetic acid. Maximum enhancement was achieved when peracetic acid was present with either chlorine or ozone and less enhancement was noted when the peracetic acid was added before chlorine dioxide. Similar results were noted when hydrochloric acid was used instead of peracetic acid. It may be concluded that the application of any two of the disinfectants studied were rarely synergistic but merely additive or complementary (i.e., one disinfectant provides the other with a medium in which it functions better).     

Catalase activity and the survival of Pseudomonas putida, a root colonizer, upon treatment with peracetic acid

Peracetic acid is used as a sterilant in several industrial settings. Cells of a plant-colonizing bacterium, Pseudomonas putida in liquid suspension, were more sensitive to killing by peracetic acid when they lacked a major catalase activity, catalase A. Low doses of peracetic acid induced promoter activity of the gene encoding catalase A and increased total catalase specific activity in cell extracts. Microbes present in native agricultural soils rapidly degraded the active oxygen species present in peracetic acid. The simultaneous release of oxygen was consistent with a role for catalase in degrading the hydrogen peroxide that is part of the peracetic acid-equilibrium mixture. Amendment of sterilized soils with wild-type P. putida restored the rate of degradation of peracetic acid to a higher level than was observed in the soils amended with the catalase A-deficient mutant. The association of the bacteria with the plant roots resulted in protection of the wild-type as well as the catalase-deficient mutant from killing by peracetic acid. No differential recovery of the wild-type and catalase A mutant of P. putida was observed from roots after the growth matrix containing the plants was flushed with peracetic acid.     

Reaction mechanism of the Co2+-activated multifunctional bromoperoxidase-esterase from Pseudomonas putida IF-3.

The reaction mechanism of the Co2+-activated bromoperoxidase-esterase of Pseudomonas putida IF-3 was studied. Site-directed mutagenesis suggested that the serine residue of the catalytic triad conserved in serine hydrolases participates in the bromination and ester hydrolysis reactions. The enzyme released a trace amount of free peracetic acid depending on the concentration of H2O2, which had been considered the intermediate in the reaction of nonmetal haloperoxidases to oxidize halide ions to hypohalous acid. However, the formation of free peracetic acid could not explain the enzyme activation effect by Co2+ ions which completely depleted the free peracetic acid. In addition, the kcat value of the enzymatic bromination was 900-fold higher than the rate constant of free peracetic acid-mediated bromination. Those results strongly suggested that the peracetic acid-like intermediate formed at the catalytic site is the true intermediate and that the formation of free peracetic acid is only a minor reaction involving the enzyme. We propose the possible reaction mechanism of this multifunctional enzyme based on these findings.     

Improved pretreatment of lignocellulosic biomass using enzymatically-generated peracetic acid

Release of sugars from lignocellulosic biomass is inefficient because lignin, an aromatic polymer, blocks access of enzymes to the sugar polymers. Pretreatments remove lignin and disrupt its structure, thereby enhancing sugar release. In previous work, enzymatically generated peracetic acid was used to pretreat aspen wood. This pretreatment removed 45% of the lignin and the subsequent saccharification released 97% of the sugars remaining after pretreatment. In this paper, the amount of enzyme needed is reduced tenfold using first, an improved enzyme variant that makes twice as much peracetic acid and second, a two-phase reaction to generate the peracetic acid, which allows enzyme reuse. In addition, the eight pretreatment cycles are reduced to only one by increasing the volume of peracetic acid solution and increasing the temperature to 60 °C and the reaction time to 6 h. For the pretreatment step, the weight ratio of peracetic acid to wood determines the amount of lignin removed.     

Mild pretreatment of yellow poplar biomass using sequential dilute acid and enzymatically-generated peracetic acid to enhance cellulase accessibility

Biomass contains cellulose, xylan and lignin in a complex interwoven structure that hinders enzymatic hydrolysis of the cellulose. To separate these components in yellow poplar biomass, we sequentially pretreated with dilute sulfuric acid and enzymatically-generated peracetic acid. In the first step, the dilute acid with microwave heating (140°C, 5 min) hydrolyzed 90% of xylan. The xylose yield in hydrolysate after dilute acid pretreatment was 83.1%. In the second step, peracetic acid (60°C, 6 h) removed up to 80% of lignin. This sequential pretreatment fractionated biomass into xylan and lignin, leaving a solid residue enriched in cellulose (~80%). The sequential pretreatment enhanced enzymatic digestibility of the cellulase by removal of the other components in biomass. The glucose yield after enzymatic hydrolysis was 90.5% at a low cellulase loading (5 FPU/g of glucan), which is 1.6 and 18 times higher than for dilute acid-pretreated biomass and raw biomass, respectively. This novel sequential pretreatment with dilute acid and peracetic acid efficiently separates the three major components of yellow poplar biomass, and reduces the amount of cellulase needed.     

Disinfection of sewage waters from rendering plants with peracetic acid]

In our experiments, peracetic acid--known in commerce as "Wolfasteril" was tested as a new and efficient disinfectant to disinfect sewage waters from rendering plants. Peracetic acid was used in experiments in concentration of 0.1 to 1.0% for 30 sec. to 60 min. As a comparative agent, 5% chloramine was used. Results obtained in preliminary and main experiments proved that peracetic acid is fully appropriate to disinfect biologically cleaned sewage waters in rendering plants. Sewage waters supplying the main stream has to pass mostly a short section after having left the water clarifier. Consequently, the concentration of 1% peracetic acid acting for 30 sec. is the optimum one. The recommendation of this application norm for peracetic acid in water clarifiers from rendering plants being at least suitable in controlling disasters.     

Biofilm-forming bacteria with varying tolerance to peracetic acid from a paper machine

Biofilms cause runnability problems in paper machines and are therefore controlled with biocides. Peracetic acid is usually effective in preventing bulky biofilms. This study investigated the microbiological status of a paper machine where low concentrations (≤15 ppm active ingredient) of peracetic acid had been used for several years. The paper machine contained a low amount of biofilms. Biofilm-forming bacteria from this environment were isolated and characterized by 16S rRNA gene sequencing, whole-cell fatty acid analysis, biochemical tests, and DNA fingerprinting. Seventy-five percent of the isolates were identified as members of the subclades Sphingomonas trueperi and S. aquatilis, and the others as species of the genera Burkholderia (B. cepacia complex), Methylobacterium, and Rhizobium. Although the isolation media were suitable for the common paper machine biofoulers Deinococcus, Meiothermus, and Pseudoxanthomonas, none of these were found, indicating that peracetic acid had prevented their growth. Spontaneous, irreversible loss of the ability to form biofilm was observed during subculturing of certain isolates of the subclade S. trueperi. The Sphingomonas isolates formed monoculture biofilms that tolerated peracetic acid at concentrations (10 ppm active ingredient) used for antifouling in paper machines. High pH and low conductivity of the process waters favored the peracetic acid tolerance of Sphingomonas sp. biofilms. This appears to be the first report on sphingomonads as biofilm formers in warm water using industries.     

Bactericidal properties of peracetic acid and hydrogen peroxide, alone and in combination, and chlorine and formaldehyde against bacterial water strains.

The bactericidal properties of peracetic acid, hydrogen peroxide, chlorine, and formaldehyde were compared in vitro using a rapid micromethod. A combination of peracetic acid and hydrogen peroxide was also tested to assess interactions. The activities of these agents, which are widely used as disinfectants, were evaluated against water isolates and culture collection strains. Peracetic acid and chlorine exhibited an excellent antimicrobial activity, with a relatively rapid destruction of 10(5) bacteria/mL. The time-dependent bactericidal activities of hydrogen peroxide and formaldehyde were the lowest. The combination of peracetic acid and hydrogen peroxide, tested by a checkerboard micromethod, was found to be synergistic. The minimal bactericidal concentration was established in terms of time for a given mixture of peracetic acid and hydrogen peroxide. Determination of bactericidal concentrations showed that synergy was maintained with increasing contact time. Concentrations for minimal times of treatment by chemicals that provided interesting activities in vitro were tested for disinfection of ultrafiltration membranes. The bactericidal activities of peroxygen compounds were confirmed and synergism was maintained in working conditions. Chlorine showed a loss of efficacy when used on membranes.     

Increased digestibility of cedar by pretreatment with peracetic acid and steam explosion

A type of steam explosion method combined with chemical pretreatment was studied. Peracetic acid was an effective reagent to assist the steam explosion reaction and greatly improved the enzymatic saccharification of cedar compared with single steam explosion. The extent of saccharification was directly proportional to the amount of peracetic acid absorbed in the chips, and the function of peracetic acid was revealed as an acid catalyst and as a radical initiator in the steam explosion reaction.     

Effect of treatment of wheat straw with ammonia and peracetic acid on digestibility in vitro and cell wall composition

Wheat straw was treated with four levels of ammonia (0, 35, 70 and 105 g kg^?1 straw dry matter), allowed to react for five days and then treated with four levels of peracetic acid (0, 40, 80 and 120 k kg^?1 straw dry matter) for five more days. There was a 1.24 percentage unit increase in dry matter digestibility in vitro (IVDMD) with each 10.0 g of ammonia added per kg of straw dry matter. The IVDMD increased 1.01 percentage unit for each 10.0 g of peracetic acid added per kg of straw dry matter. The lignin content of the straw decreased 0.39% with each 10.0 g of peracetic acid added per kg of straw dry matter. The hemicellulose content of the straw decreased 0.82% with the addition of 10.0 g of ammonia per kg of straw dry matter. Cellulose content was not affected by the addition of peracetic acid or ammonia.The development of more economical and safe procedures which combine swelling and delignification would be very beneficial for improving the nutritive value of low quality roughages.     

A note on the effect of sporulation conditions on the resistance of Bacillus spores to heat and chemicals

Spores of Bacillus subtilis SA22 harvested after 22 d incubation on nutrient agar at 30°C were more resistant to 0–04% peracetic acid at 20°C than spores harvested following 2 d incubation. Similarly, spores of B. subtilis globigii B17, harvested after 7 d incubation on a sporulation agar were up to 10 times less resistant to 0.04% peracetic acid at 20°C than spores harvested after 35 d incubation. An increase in resistance to heating at 100°C and to exposure to 17.7% hydrogen peroxide at 20°C occurred as the age of B. subtilis SA22 spores prior to harvesting increased, whereas differences in resistance were not observed with spores of B. subtilis globigii B17.     

Evaluation of the efficiency of peracetic acid in the disinfection of sewage effluents

AIMS: Evaluation of the efficiency of peracetic acid in the disinfection of wastewater in a large treatment plant. METHODS AND RESULTS: Over a period of 18 months 30 sample collections were made, each consisting of three samples taken from: raw incoming sewage, secondary effluent (after 10-12 h) and secondary effluent disinfected with 1.5-2 mg l(-1) of peracetic acid (contact time: 20 min). Total coliforms and Escherichia coli declined from 10(7) MPN 100 ml(-1) in the raw sewage to 10(2) in the disinfected effluent and the enterococci fell from 10(6) MPN 100 ml(-1) to 702 MPN 100 ml(-1). The reduction of bacteria increased with the rise in temperature and decreased with the rise in BOD5. CONCLUSIONS: Disinfection with peracetic acid reduced levels of faecal contamination by 97%, thus attaining the limit recommended by current Italian law (Escherichia coli 相似文献   

Development of a new technique for obtaining axenic meat

Summary A new technique for obtaining axenic meat is described. The procedure is based on the use of a liquid peracetic acid lock united with two isolators, permanently connected together. After immersion in a 3% solution of peracetic acid for 2 min, the surfaces of muscles obtained from pig, horse and cattle were shown to be completely decontaminated. Such meats appeared perfectly fit for gnotobiotic studies in the field of meat microbiology.     

Sensitivity of yeast vegetative cells and ascospores to biocides and environmental stress

The sensitivity of vegetative cells and ascospores of Saccharomyces cerevisiae to a range of biocides used in food industry hygiene was compared. Ascospores were significantly more resistant to quaternary ammonium compounds and hypochlorite but not peracetic acid. Ascospores also showed greater tolerance of desiccation than vegetative cells.     

Cloning and biochemical characterization of Co(2+)-activated bromoperoxidase-esterase (perhydrolase) from Pseudomonas putida IF-3 strain

The gene encoding Co(2+)-activated bromoperoxidase (BPO)-esterase (EST), catalyzing the organic acid-assisted bromination of some organic compounds with H2O2 and Br(-) and quite specific hydrolysis of (R)-acetylthioisobutyric acid methyl ester, was cloned from the chromosomal DNA of the Pseudomonas putida IF-3 strain. The bpo-est gene comprises 831 bp and encoded a protein of 30181 Da. The enzyme was expressed at a high level in Escherichia coli and purified to homogeneity by ammonium sulfate fractionation and two-step column chromatographies. The recombinant enzyme required acetic acid, propionic acid, isobutyric acid or n-butyric acid in addition to H2O2 and Br(-) for the brominating reaction and was activated by Co(2+) ions. It catalyzed the bromination of styrene and indene to give the corresponding racemic bromohydrin. Although the enzyme did not release free peracetic acid in the reaction mixture, chemical reaction with peracetic acid could well explain such enzymatic reactions via a peracetic acid intermediate. The results indicated that the enzyme was a novel Co(2+)-activated organic acid-dependent BPO (perhydrolase)-EST, belonging to the non-metal haloperoxidase-hydrolase family.     

Selective oxidation of carbohydrates by 4-AcNH-TEMPO/peracid systems

Starch, amylopectin, inulin, pullulan and methyl α- -glucopyranoside (Me α-Glcp) were oxidised by 4-acetamido-2,2,6,6-tetramethylpiperidine-1-oxyl (4-AcNH-TEMPO) as the mediator and peracetic acid or monoperoxysulfate (Oxone^®) as the regenerating oxidant. The conversion of primary alcohol groups to the corresponding carboxyl groups proceeded with high yield and selectivity, provided that sodium bromide was added as co-catalyst.The mass molecular distributions of the oxidised polysaccharides indicated that no major depolymerisation occurred during oxidation. Oxone appeared to be the most efficient oxidant as the reaction rate was 25 times higher than that of peracetic acid in the oxidation of Me α-Glcp. On the other hand, oxone produces a larger amount of waste as by-product than peracetic acid.     

Characterization of vanadium bromoperoxidase from Macrocystis and Fucus: reactivity of vanadium bromoperoxidase toward acyl and alkyl peroxides and bromination of amines

Vanadium bromoperoxidase (V-BrPO) has been isolated and purified from the marine brown algae Fucus distichus and Macrocystis pyrifera. V-BrPO catalyzes the oxidation of bromide by hydrogen peroxide, resulting in the bromination of certain organic acceptors or the formation of dioxygen. V-BrPO from F. distichus and M. pyrifera have subunit molecular weights of 65,000 and 74,000, respectively, and specific activities of 1580 units/mg (pH 6.5) and 1730 units/mg (pH 6) for the bromination of monochlorodimedone, respectively. As isolated, the enzymes contain a substoichiometric vanadium/subunit ratio; the vanadium content and specific activity are increased by addition of vanadate. V-BrPO (F. distichus, M. pyrifera, and Ascophyllum nodosum) also catalyzes the oxidation of bromide using peracetic acid. In the absence of an organic acceptor, a mixture of oxidized bromine species (e.g., hypobromous acid, bromine, and tribromide) is formed. Bromamine derivatives are formed from the corresponding amines, while 5-bromocytosine is formed from cytosine. In all cases, the rate of the V-BrPO-catalyzed reaction is much faster than that of the uncatalyzed oxidation of bromide by peracetic acid, at pH 8.5, 1 mM bromide, and 2 mM peracetic acid. In contrast to hydrogen peroxide, V-BrPO does not catalyze formation of dioxygen from peracetic acid in either the presence or absence of bromide. V-BrPO also uses phenylperacetic acid, m-chloroperoxybenzoic acid, and p-nitroperoxybenzoic acid to catalyze the oxidation of bromide; dioxygen is not formed with these peracids. V-BrPO does not catalyze bromide oxidation or dioxygen formation with the alkyl peroxides ethyl hydroperoxide, tert-butyl hydroperoxide, and cuminyl hydroperoxide.     

Sugar production from agricultural woody wastes by saccharification with Trichoderma viride cellulase.

The saccharification of agricultural woody wastes was studied using a commercial enzyme preparation, Cellulase onozuka, derived from Trichoderma viride or the solid culture extracts of the fungus. With the intention of producing sugar at low cost, a simple procedure of enzymatic saccharification of rice straw, bagasse, and sawdust was studied. Delignifying methods of these wastes were investigated using dilute sodium hydroxide solution and dilute peracetic acid. Rice straw and bagasse were effectively delignified by boiling in a 1% sodium hydroxide solution for 3 hr or by autoclaving at 120 degrees C in a 1% sodium hydroxide solution for 1 hr. The sawdust from a broad leaved tree (Machilus thunbergii) was delignified by autoclaving at 120 degrees C in a 1% sodium hydroxide solution for 1 hr and by subsequent boiling in diluted 1/5 peracetic acid for 1 hr. This type of sawdust was also delignified by boiling in 1/5 peracetic acid for 1 hr and by subsequent autoclaving at 120 degrees C in a 1% sodium hydroxide solution for 1 hr. The sawdust from a coniferous tree (Cryptomeria japonica) was delignified by boiling in 1/5 peracetic acid for 1 hr and by subsequent autoclaving at 120 degrees C in a 1% sodium hydroxide solution for 1 hr; however, the successive treatment by autoclaving with alkali solution and subsequent boiling with diluted peracetic acid failed to bring about the desired effect. The saccharification of delignified rice straw, bagasse, and sawdust was examined using Cellulase onozuka, wheat bran or rice straw solid culture at various substrate concentrations, resulting in the formation of 5 to 10% sugar solutions after incubation at pH 5.0, 45 degrees C for 48 hr. The optimum substrate concentration existed at around 10%. Reuse of cellulase solution and resaccharification of residual sawdust were considered to be inadequate.