Degradation Of Pentachlorophenol In Soil Research Articles

Verification of Heme Catalytic Cycle with 5-Aminosalicylic Acid and Its Application to Soil Remediation of Polycyclic Aromatic Hydrocarbons

Catalytic degradation of pentachlorophenol in soil by heme and hydrogen peroxide has been hypothesized to occur through nonspecific catalytic reactions similar to those involving ligninase. The present study examines the evidence for a heme catalytic mechanism for the oxidation of organic compounds. In the presence of hydrogen peroxide, heme is converted to the ferryl heme radical (Hm-Fe +4• ), which can oxidize organic compounds, such as 5-aminosalicylic acid (5-ASA). A second 5-ASA may later be oxidized by ferryl heme (Hm-Fe +4 ), which reverts to the ferric heme state (Hm-Fe +3 ) to complete the cycle. We believe that this catalytic cycle is involved in the degradation of hazardous pollutants, such as polycyclic aromatic hydrocarbons (PAHs). Remediation via heme catalytic reactions of PAHs in soil from a pole yard was evaluated, and about 96% of PAHs was found to disappear within 42 days after treatment with heme and hydrogen peroxide. In addition, benzo[a]pyrene and six other PAHs were undetectable among a total of 16 PAH compounds examined. Therefore, we propose heme catalysis as a novel technology for the remediation of hazardous compounds in contaminated soil.

Kinetics studies on pentachlorophenol degradation in soil during pulsed discharge plasma process

Abstract Pentachlorophenol (PCP) degradation kinetics in soil during pulse discharge processes was studied experimentally and theoretically in terms of high-energy electrons, PCP initial concentration, oxygen concentration, and treatment time. Higher PCP degradation efficiency was obtained with more high-energy electrons; 83.9% of PCP was degraded at high-energy electrons 1.9 × 1012/pulse after 60 min's treatment, which decreased to 60.9% at high-energy electrons 6.8 × 1011/pulse. Lower PCP concentration, higher oxygen concentration and longer treatment time benefited PCP degradation. Numerical simulations were conducted to simulate PCP degradation processes. By qualitatively comparing the experimental and theoretical results, it was found that PCP degradation behaviors were exactly similar.

Degradation of pentachlorophenol in soil by pulsed corona discharge plasma

The remediation of pentachlorophenol (PCP) contaminated soil using pulsed corona discharge plasma was reported in this study. The effect of practical run parameters such as peak pulse voltage, pulse frequency, gas atmospheres (air, O 2, Ar and N 2), air flow rate and pollution time on PCP degradation was investigated, and the intermediate products were also studied. The results indicated that PCP degradation efficiency increased with an increase in peak pulse voltage or pulse frequency, due to the enhancement of energy input. There existed a maximal PCP degradation efficiency with the change of air flow rate. PCP degradation efficiencies under oxygen and air atmospheres were achieved 92% and 77% after 45 min of discharge treatment at 14.0 kV, respectively, which were only 19% and 8% under argon and nitrogen atmospheres, respectively. O 3 played an important role in PCP degradation. However, other processes also contributed to PCP degradation, such as N, N 2 +, N + and OH. The pollution time evidenced slight influence on PCP degradation. The main intermediate products produced during the treatment process were identified as tetrachlorocatechol, tetrachlorohydroquinone, acetic acid, formic acid and oxalic acid by HPLC/MS and ion chromatography. This study is expected to provide reference for the application of pulsed corona discharge in soil remediation.

Evaluation of the Potential of Pentachlorophenol Degradation in Soil by Pulsed Corona Discharge Plasma from Soil Characteristics

Chlorinated organics are frequently found as harmful soil contaminants and persisted for extended periods of time. A novel approach, named pulsed corona discharge plasma (PCDP), was employed for the degradation of pentachlorophenol (PCP) in soil. Experimental results showed that 87% of PCP could be smoothly removed in 60 min. Increasing pulse voltage, enhancing soil pH, lowering humic acid (HA) in soil and reducing granular size of the soil were found to be favorable for PCP degradation efficiency. Oxidation and physical processes simultaneously contributed to PCP removal in soil and ozone was the main factor in PCDP treatment. C-Cl bonds in PCP were cleaved during PCDP treatment by Fourier transform infrared spectroscopy (FTIR) analysis. The mineralization of PCP was confirmed by total organic carbon (TOC) and dechlorination analyses. The main intermediate products such as tetrachlorocatechol, tetrachlorohydroquinone, acetic acid, formic acid, and oxalic acid were identified by HPLC/MS and ion chromatography. A possible pathway of PCP degradation in soil in such a system was proposed.

Kinetics of Pentachlorophenol Degradation in Soil Using Heme and Peroxide

Kinetics of an abiotic method for oxidative pentachlorophenol (PCP) degradation in soil under unsaturated conditions and a neutral pH has been studied. Reagents used were heme as the catalyst and peroxide as the oxidant. Our previous results showed that the heme and peroxide degraded PCP efficiently with two optimum doses of heme and peroxide: one was the optimum point derived from the quadratic model fitting with heme of 0.035 g∕2 g soil and peroxide of 0.105 g∕2 g soil; the other had lower doses of heme ( 0.017 g∕2 g soil) and peroxide ( 0.095 g∕2 g soil) derived from the calculation of 95% confidence interval of the optimum point. Based on these results, the purpose of this study was to examine the kinetics of soil PCP degradation in terms of the rate and extent of PCP destruction at the optimal dosages determined. The results showed that PCP degradation at both optimal dosages looked similar, which showed about 70% of PCP destruction within the first 2 h of reaction and up to 80% of PCP destruction wi...

PELLETIZATION OF Anthracophyllum discolor FOR WATER AND SOIL TREATMENT CONTAMINATED WITH ORGANIC POLLUTANTS

Pellets of the white-rot fungus Anthracophyllum discolor with activated carbon and sawdust (complex pellets) were formulated for the degradation of lignin in water and the bioremediation of soil contaminated with pentachlorophenol (PCP). The complex pellets were formed by a center of activated carbon and sawdust surrounded by fungal mycelium, whereas simple pellets consisting of only mycelium were hollow spheres. Degradation of lignin was performed in an airlift reactor at initial lignin concentration of 1000 mg L -1 and the fungal pellets were re-used two times in batch operations. Complex pellets degraded lignin by 87 and 72% in the first and second cycle, respectively, and they were significantly more effective than simple pellets. In addition, complex pellet showed higher manganese peroxidase activity in the reactor. For the bioremediation of soil contaminated with PCP (150 mg kg -1 of soil) the pellets were added to soil surface. PCP degradation in soil with complex pellets was 85% at 28 days of bioaugmentation, being higher than in soil with simple pellet. A fungus growth was also observed only in soil with complex pellet. Sawdust and activated carbon appear to be suitable carriers of A. discolor for degradation of organic pollutants in wastewater and soil.

Bioaugmentation of pentachlorophenol in soil and hydroponic systems

Abstract Sphingobium chlorophenolicum is well known as pentachlorophenol (PCP) degrader. The objective of this study was to evaluate the PCP degradation in soil and hydroponic systems using a bioaugmentation technique. Measurements of PCP concentrations were carried out using high-performance liquid chromatography (HPLC) analyses. The toxic effect of PCP on plants was studied through the monitoring of plant weight. An acute toxicity assay of PCP was performed using Escherichia coli HB101 pUCD607. The introduction of S. chlorophenolicum into soil with plants showed a faster degradation when compared to the non-inoculated soil. In the soil system, plants acted as a vector to the target compound, PCP. The monitoring of the plant growth showed a protective role of S. chlorophenolicum against the toxicity of PCP. In the hydroponic system S. chlorophenolicum showed the ability to degrade 16 mg l−1 after 7 days of experiments at both concentrations tested (20 and 30 mg l−1 PCP). The bioassay confirmed that initial toxicity was lowered while degradation progressed in both systems.

Treating Soil PCP at Optimal Conditions Using Heme and Peroxide

The environmental impact of pentachlorophenol (PCP) has been the subject of extensive research in recent years. Investigations of PCP degradation using both biotic and abiotic methods are extensively reported in literature. Based on some preliminary tests (not shown), an abiotic method was found for oxidative PCP degradation in soil under unsaturated conditions and a neutral pH. Reagents used were heme (a catalyst) and peroxide (an oxidant). From two screening tests (not shown), the heme and peroxide were identified as the most important factors on PCP degradation in highly PCP-contaminated soil. The objective of this study was to determine the optimum doses of heme and peroxide for PCP degradation in soil. Using a statistical method, known as response surface methodology, a quadratic function was fit to the data and used to estimate the optimum doses of heme and peroxide at 0.035 g∕2 g -soil and 0.105 g∕2 g -soil, respectively, in treating PCP-contaminated soil. The model also was used to determine the r...

Cultivation‐independent in situ molecular analysis of bacteria involved in degradation of pentachlorophenol in soil

The central aim of this study was to determine which components of an indigenous bacterial community in pristine grassland soil were capable of degrading pentachlorophenol (PCP) using two cultivation-independent, in situ, molecular techniques. The first involved polymerase chain reaction (PCR) and reverse transcription polymerase chain reaction (RT-PCR) amplification of 16S rRNA genes from DNA and RNA, respectively, extracted from PCP-amended soil. The second involved stable isotope probing (SIP), with incubation of soil with 13C-PCP and molecular analysis of 13C-labelled RNA, derived from cells incorporating PCP or its breakdown products, after separation from 12C-RNA by ultracentrifugation. Bacterial communities were characterized by denaturing gradient gel electrophoresis (DGGE) analysis of amplification products. PCP was degraded at an approximate rate of 1.18+/-0.25 (SEM) mg kg-1 day-1 and 39% of the measurable PCP fraction was degraded after incubation for 63 days. PCP degradation was associated with significant changes in bacterial community structure, leading to the appearance of seven bands in both DNA- and RNA-based DGGE profiles, the latter providing clearer evidence of qualitative shifts in community structure. The majority of novel bands increased in relative intensity during the first 35 days and subsequently decreased in relative intensity as incubation continued. Sequence and phylogenetic analysis of six of these bands indicated most to have closest database relatives that were uncultured bacteria with sequence homologies to reported hydrocarbon degraders. No band could be detected in RNA-SIP-DGGE profiles derived from 13C-RNA fractions at day 0 but several faint bands appeared in these fractions after incubation of soil for 4 days, indicating assimilation of PCP or its degradation products. These bands increased in intensity during subsequent incubation for 21 days and decreased with further incubation. With one exception, RNA-SIP-DGGE and RNA-DGGE profiles were similar, indicating that RNA-targeted DGGE, in this case, provided a good indication of the metabolically active microbial community.

Aerobic and Anaerobic Biodegradation of Aged Pentachlorophenol by Indigenous Microorganisms

Pentachlorophenol (PCP) use as a general biocide, particularly for treating wood, has led to widespread environmental contamination. Biodegradation has emerged as the main mechanism for PCP degradation in soil and groundwater and a key strategy for remediation. Examining the microbial biodegrading potential for PCP at a contaminated site is crucial in determining its fate. Hundreds of studies have been published on PCP microbial degradation, but few have described the biodegradation of PCP that has been in contact with soils for many years. The bioavailability of “aged” hydrophobic organics is a significant concern. PCP- and 2,3,4,6-tetrachlorophenol (2,3,4,6-TeCP)-contaminated soil samples from several depths at a former wood treatment site were placed under varying conditions in the laboratory to determine the anaerobic and aerobic potential for biodegradation of chlorophenols at the site. PCP biodegradation occurred in both anaerobic and aerobic soil samples. Rapid aerobic degradation occurred in samples spiked with 2- and 4-chlorophenol, but not with 3-chlorophenol. Reductive dechlorination of PCP in anaerobic samples resulted in the accumulation of 3-chlorophenol. In most anaerobic replicates, 3-chlorophenol was degraded with the appearance of detectable, but not quantifiable amounts of phenol. These results indicate excellent potential for remediation at the site using the indigenous microorganisms under both aerobic and anaerobic conditions. However, a fraction of the PCP was unavailable for degradation.

Degradation of pentachlorophenol in soil by streptomyces rochei 303

The fate of pentachlorophenol (PCP) in soil under natural conditions was investigated. It was revealed that the total amount of PCP significantly decreased when soil was inoculated by Streptomyces rochei 303, a strain‐destructor of chlorophenols. The products of PCP transformation, such as tetra‐ and trichlorophenols, pentachloro‐benzene, chlorinated dioxins, were identified after the first month of the experiment. Their quantity was less in the variant with the introduced strain compared to control.

Degradation of pentachlorophenol in soil by Phanerochaete chrysosporium

Biodegradation of pentachlorophenol (PCP) by Phanerochaete chrysosporium was examined in nonsterile soil. The rate of mineralization of PCP was essentially linear for at least 27 d and increased almost linearly with increasing concentration of PCP (from 50 to 1600 ppm). At 100 ppm no PCP was found at 18 d while 40% of the added PCP was present as pentachloroanisole (PCA), and mineralization continued linearly. Both PCP and PCA were found after 18 d when the initial concentration of PCP was 800 ppm. The rate of mineralization of PCA also increased with increasing concentrations of PCA, however the increase was not linear. Essentially no radioactivity was found in either the aqueous or volatile organic fraction during the mineralization of either PCP or PCA.

Hycrest crested wheatgrass accelerates the degradation of pentachlorophenol in soil.

We investigated the effects of vegetation on the fate of pentachlorophenol (PCP) in soil using a novel high-flow sealed test system. Pentachlorophenol has been widely used as a wood preservative, and this highly toxic biocide contaminates soil and ground water at many sites. Although plants are known to accelerate the rates of degradation of certain soil contaminants, this approach has not been thoroughly investigated for PCP. The fate of [14C]PCP, added to soil at a concentration of 100 mg/kg, was compared in three unplanted and three planted systems. The plant used was Hycrest, a perennial, drought-tolerant cultivar of crested wheatgrass [Agropyron desertorum (Fischer ex Link) Schultes]. The flow-through test system allowed us to maintain a budget for 14C-label as well as monitor mineralization (breakdown to 14CO2) and volatilization of the test compound in a 155-d trial. In the unplanted systems, an average of 88% of the total radiolabel remained in the soil and leachate and only 6% was mineralized. In the planted system, 33% of the radiolabel remained in the soil plus leachate, 22% was mineralized, and 36% was associated with plant tissue (21% with the root fraction and 15% with shoots). Mineralization rates were 23.1 mg PCP mineralized kg-1 soil in 20 wk in the planted system, and for the unplanted system 6.6 mg PCP kg-1 soil for the same time period. Similar amounts of volatile organic material were generated in the two systems (1.5%). Results indicated that establishing crested wheatgrass on PCP-contaminated surface soils may accelerate the removal of the contaminant.

Enhancement of pentachlorophenol degradation in soil through induced anaerobiosis and bioaugmentation with anaerobic sewage sludge

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEnhancement of pentachlorophenol degradation in soil through induced anaerobiosis and bioaugmentation with anaerobic sewage sludgeMark D. Mikesell and Stephen A. BoydCite this: Environ. Sci. Technol. 1988, 22, 12, 1411–1414Publication Date (Print):December 1, 1988Publication History Published online1 May 2002Published inissue 1 December 1988https://doi.org/10.1021/es00177a003RIGHTS & PERMISSIONSArticle Views213Altmetric-Citations46LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (495 KB) Get e-Alerts Get e-Alerts

PCP連用圃場のPCP分解菌とPCP耐性菌の菌数変化 : 土壌中でのペンタクロロフェノールの分解(第2報)

PCP連用圃場のPCP分解菌とPCP耐性菌の菌数変化 : 土壌中でのペンタクロロフェノールの分解(第2報)