Cometabolic biodegradation of chlorinated ethenes with methanotrophs in anaerobic/aerobic simulated aquifer

Aim: This study explores anaerobic/aerobic biodegradation efficiencies of aerobic cometabolism with methanotrophs when contaminants trichloroethylene (TCE) and cis-1,2-dichloroethylene (cDCE) are present individually or in tandem. Methodology: Batch tests and an anaerobic/aerobic column system were used to simulate saturated, contaminated aquifers. A brown glass bottle with an effective volume of 44 m l-1 was prepared for the batch test. An integrated one-dimensional sequential anaerobic/aerobic column system was used to simulate the accumulative intermediates such as TCE, cDCE and VC caused by incomplete degradation of PCE during the upgradient anaerobic stage in the saturated aquifer. In the downgradient aquifer, aerobic cometabolism was employed to degrade the intermediates. Methanotrophs in the aerobic aquifer were inoculated to degrade the by-products of incomplete degradation of PCE by aerobic cometabolism. Results: In the batch test, biodegradation of TCE was significantly inhibited by cDCE. However, biodegradation of cDCE was not significantly inhibited by TCE. In the simulated aquifer test, aerobic cometabolism completely degraded intermediates (TCE, cDCE, and VC) produced by incomplete anaerobic degradation of tetrachloroethylene (PCE). The results showed that methane, a by-product of anaerobic reductive dechorination of PCE, was used as a primary substrate for aerobic degradation, at a utilization rate of almost 100%. Interpretation: Biodegradation of TCE was significantly inhibited by cDCE. Bioremediation should have sufficient oxygen and methane at aerobic stage to ensure that chlorinated ethenes fully mineralize.

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Anaerobic/aerobic biodegradation of pentachlorophenol using GAC fluidized bed reactors: optimization of the empty bed contact time

Water Science & Technology ◽

10.2166/wst.1997.0581 ◽

1997 ◽

Vol 36 (6-7) ◽

pp. 107-115 ◽

Cited By ~ 4

Author(s):

Gregory J. Wilson ◽

Amid P. Khodadoust ◽

Makram T. Suidan ◽

Richard C. Brenner

Keyword(s):

Fluidized Bed ◽

Oxygen Demand ◽

Aerobic Biodegradation ◽

Fluidized Bed Reactors ◽

Reactor Performance ◽

Reactor Operation ◽

Significant Cost ◽

Second Stage ◽

Primary Substrate ◽

Chlorinated Phenolic Compounds

An integrated reactor system has been developed to remediate pentachlorophenol (PCP) containing wastes using sequential anaerobic and aerobic biodegradation. Anaerobically, PCP was degraded to predominately equimolar concentrations (>99%) of monochlorophenol (MCP) in two GAC fluidized bed reactors at Empty Bed Contact Times (EBCTs) ranging from 18.6 to 1.15 hours. However, at lower EBCTs, MCP concentrations decreased to less than 10% of the influent PCP concentration suggesting mineralization. The optimal EBCT was determined to be 2.3 hours based on PCP conversion to MCPs and stable reactor operation. Decreasing the EBCT fourfold did not inhibit degradation of PCP and its intermediates, thus allowing removal of PCP at much lower detention time and resulting in a significant cost advantage. Analytical grade PCP was fed via syringe pumps into two fluidized bed reactors at influent concentrations of 100 mg/l and 200 mg/l, respectively. Acting as the primary substrate, ethanol was also fed into the reactors at concentrations of 697 and 1388 mg/l. Effluent PCP and chlorinated phenolic compounds were analyzed weekly to evaluate reactor performance. Biodegradation pathways were also identified. 3-chlorophenol (CP) was the predominant MCP and varied simultaneously with 3,5-dichlorophenol (DCP) concentrations. Likewise, 4-CP concentrations varied simultaneously with 3,4-DCP concentrations. A second stage aerobic GAC fluidized bed reactor was added after the anaerobic reactor to completely mineralize the remaining MCP and phenols. Data show no presence of phenol and MCP in the effluent or on the GAC. Overall, the chemical oxygen demand (COD) fed to the system was reduced from 75 g/d in the influent to less than 1.5 g/d in the effluent.

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Thermoplastic Blends Based on Poly(Butylene Succinate-co-Adipate) and Different Collagen Hydrolysates from Tanning Industry—II: Aerobic Biodegradation in Composting Medium

Journal of Polymers and the Environment ◽

10.1007/s10924-021-02124-3 ◽

2021 ◽

Author(s):

Roberto Altieri ◽

Maurizia Seggiani ◽

Alessandro Esposito ◽

Patrizia Cinelli ◽

Vitale Stanzione

Keyword(s):

Chemical Characterization ◽

Aerobic Biodegradation ◽

Lepidium Sativum ◽

Biodegradation Rate ◽

Butylene Succinate ◽

Dog Bone ◽

Thermoplastic Blends ◽

Collagen Hydrolysates ◽

By Products ◽

Tanning Industry

AbstractTwo different raw hydrolyzed collagens (HCs), by-products of the Tannery industry, were investigated in blends with a bioplastic, as poly(butylene succinate-co-adipate) (PBSA), for the production of thermoplastic items for possible applications in agriculture. Chemical characterization of selected PBSA/HC blends and phytotoxicity assays on garden cress seeds (Lepidium sativum L.), used as spy species, were carried out; in addition, biodegradation and disintegration of specimens were assessed under controlled composting conditions at different temperature (58 and 25 °C). Although one of the HC investigated released sodium chloride in the aqueous extract, all PBSA/HC blends, up to 20 wt.% HC, resulted no-phytotoxic and showed considerable amounts of macro- and micro- nutrients for plants (mainly nitrogen). Regardless the amount added, HCs enhanced the biodegradation rate of PBSA/HC blends in compost at 58 °C compared to pure PBSA; lowering the temperature at 25 °C, as expected, biodegradation rate slightly lowered using the same compost. Most disintegration tests, performed on dog bone samples, corroborated the results of the biodegradation tests, thus suggesting that plastic mixtures could reasonably end their life cycle in a composting facility without decreasing the quality and the safety of the resulting compost. The outcomes achieved encourage the use of raw collagen hydrolysates from tanning industry in the production of PBSA-based thermoplastic blends to produce compostable items (mulching films and/or plant pots) for more sustainable uses in agriculture and/or plant nurseries. In addition, the use of these low-cost by-products can lower the cost of final product and give it fertilizing properties for plants given the presence of organic nitrogen in the hydrolysates.

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Pilot studies for in-situ aerobic cometabolism of trichloroethylene using toluene-vapor as the primary substrate

Water Research ◽

10.1016/j.watres.2004.08.009 ◽

2004 ◽

Vol 38 (19) ◽

pp. 4125-4134 ◽

Cited By ~ 12

Author(s):

M.C. Tom Kuo ◽

K.F. Liang ◽

Y.L. Han ◽

K.C. Fan

Keyword(s):

Pilot Studies ◽

Toluene Vapor ◽

Aerobic Cometabolism ◽

Primary Substrate

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Bioactive Peptides from Walnut Residue Protein

Molecules ◽

10.3390/molecules25061285 ◽

2020 ◽

Vol 25 (6) ◽

pp. 1285 ◽

Cited By ~ 1

Author(s):

Xiangyang Li ◽

Manli Guo ◽

Jingtian Chi ◽

Jiangang Ma

Keyword(s):

Bioactive Peptides ◽

Added Value ◽

Structure Identification ◽

Antihypertensive Activity ◽

Utilization Rate ◽

Effective Utilization ◽

Active Peptides ◽

Reference Information ◽

Excellent Health ◽

By Products

Walnut residue is a kind of high-quality plant protein resource. The bioactive peptide prepared from walnut residue has excellent health care functions such as antioxidation and antihypertensive activity, but at present, walnut residue is often regarded as waste or low value feed, fertilizer and other materials. The uneconomical use of walnut residue has hindered the development of the walnut industry to some extent. Effective utilization of walnut residue protein to develop bioactive peptides and other products is of great significance to realize the comprehensive utilization of walnut residue, improve the added value of by-products, and change the current low utilization rate of walnut residue. In this paper, the preparation, purification and structure identification of walnut protein bioactive peptides are reviewed, and different functional walnut active peptides (WBPs) are introduced. The potential effects of these bioactivities on human health and their different uses in food, medicine and other industries are discussed. The purpose is to provide reference information for the effective utilization of walnut residue resources and the development of walnut industry.

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Sequential anaerobic/aerobic biodegradation of chlorinated hydrocarbons in activated carbon barriers

Water Science & Technology Water Supply ◽

10.2166/ws.2002.0045 ◽

2002 ◽

Vol 2 (2) ◽

pp. 51-58 ◽

Cited By ~ 3

Author(s):

A. Tiehm ◽

M. Gozan ◽

A. Müller ◽

H. Schell ◽

H. Lorbeer ◽

...

Keyword(s):

Hydrogen Peroxide ◽

Biological Activity ◽

Activated Carbon ◽

Vinyl Chloride ◽

Reductive Dechlorination ◽

Chlorinated Hydrocarbons ◽

Aerobic Biodegradation ◽

Anaerobic Conditions ◽

Biological Activated Carbon ◽

Batch Tests

The aim of this study is to develop a long lasting, sequential anaerobic/aerobic biological activated carbon barrier. In the biobarrier, pollutant adsorption on granular activated carbon (GAC) and biodegradation occur simultaneously. Trichloroethene (TCE), chlorobenzene (CB), and benzene were used as model pollutants. In the first barrier, that was operated under anaerobic conditions with sucrose and ethanol as auxiliary substrates, TCE was completely converted to lower chlorinated metabolites, predominantly cis-dichloroethene (cis-DCE). The reductive dechlorination process was stable for about 300 d, although the concomitant sulphate-reducing and methanogenic processes varied considerably. In the second barrier, that was operated with addition of hydrogen peroxide and nitrate, dechlorination was limited by a lack of oxygen and restricted mainly to CB biodegradation. Additional aerobic batch tests revealed that the metabolites of anaerobic TCE dechlorination, i.e. cis-DCE and vinyl chloride, were oxidatively dechlorinated in the presence of suitable auxiliary substrates such as ethene, CB, benzene, or sucrose and ethanol. During periods of low biological activity, elimination of TCE and CB occurred by adsorption in the GAC barriers. The pre-sorbed pollutants were available for subsequent biodegradation resulting in a bioregeneration of the activated carbon barriers.

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Changes in the composition of wastewater as a result of dehydrochlorination of 1,3-dichloropropan-2-ol under different process conditions

Polish Journal of Chemical Technology ◽

10.2478/pjct-2014-0016 ◽

2014 ◽

Vol 16 (1) ◽

pp. 92-96

Author(s):

Anna Krzyżanowska ◽

Eugeniusz Milchert ◽

Marcin Bartkowiak

Keyword(s):

Alkali Solution ◽

Process Conditions ◽

Column System ◽

By Products

Abstract The results of dehydrochlorination of 1,3-dichloropropan-2-ol to epichlorohydrin are reported. The process ran in the reaction-stripping column system with a continuous removal of epichlorohydrin in a steam stream. The influence of 10 wt% alkali solution (NaOH, Ca(OH)2) and the method of distillate collection on the 1,3-dichloropropan-2-ol conversion, selectivity of transformation to epichlorohydrin and by-products, and the composition of wastewater have been analysed.

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Caloric Delineation of Gasoline Blends using Dsc

International Journal of Innovative Technology and Exploring Engineering - Special Issue ◽

10.35940/ijitee.d2045.029420 ◽

2020 ◽

Vol 9 (4) ◽

pp. 2752-2755

Keyword(s):

Heat Flow ◽

Greenhouse Gas Emissions ◽

Greenhouse Gas ◽

Rheological Behavior ◽

Spark Ignition ◽

Considerable Improvement ◽

Utilization Rate ◽

Si Engine ◽

Air Atmosphere ◽

By Products

Petroleum by-products are now contemporary utilization rate it will be consuming in upcoming periods.Ethanol usage is one of the transport sectors can fulfill the requirement and contribute to mitigating the greenhouse gas emissions of the vehicles. In order to expand the SI engine which can function on 100% ethanol or append ethanol in petrol and operate the blends of that. The intention of this project is going to prepare the thermal and rheological behavior of pure petrol, E5 and E10, E15 ethanol-gasoline blend. All thermograms of heat flow exhibited at a 35ºC-280ºC temperature range at air atmosphere. This contemplation concludes that ethanol blending is the lowest exhaust gasses with considerable improvement in the performance of the Spark Ignition (SI) engine and promising, Ethanol as a new fuel which can be fortunately replace petrol and its depletion problem

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Kinetic Parameters of Saccharomyces cerevisiae Alcohols Production Using Nepenthes mirabilis Pod Digestive Fluids-Mixed Agro-Waste Hydrolysates

Fermentation ◽

10.3390/fermentation5010010 ◽

2019 ◽

Vol 5 (1) ◽

pp. 10 ◽

Cited By ~ 1

Author(s):

Nkosikho Dlangamandla ◽

Seteno Ntwampe ◽

Justine Angadam ◽

Boredi Chidi ◽

Maxwell Mewa-Ngongang

Keyword(s):

Saccharomyces Cerevisiae ◽

Product Yield ◽

Product Formation ◽

Relative Difference ◽

Substrate Utilization ◽

Utilization Rate ◽

Alcohol Production ◽

Dehydrochlorination of 1,3-Dichloropropan-2-Ol by Calcium and Sodium Hydroxide Solutions

Polish Journal of Chemical Technology ◽

10.2478/pjct-2014-0056 ◽

2014 ◽

Vol 16 (3) ◽

pp. 86-90 ◽

Cited By ~ 1

Author(s):

Anna Krzyżanowska ◽

Eugeniusz Milchert ◽

Marcin Bartkowiak

Keyword(s):

Aqueous Solution ◽

Aqueous Solutions ◽

Sodium Hydroxide ◽

Column System ◽

By Products

Abstract The results of dehydrochlorination of 88 wt% aqueous solution of 1,3-dichloropropan-2-ol to epichlorohydrin are reported. The process was carried out in the reaction-stripping column system with a continuous removal of epichlorohydrin in the steam stream. Aqueous solutions of sodium and calcium hydroxides at concentrations in the range of 3-14 wt% were used for the dehydrochlorination. The infl uence of the type and concentration of dehydrochlorination agent on 1,3-dichloropropan-2-ol conversion, the selectivity of transformation to epichlorohydrin and by-products, and the composition of distillate and wastewater were studied.

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Toluene Biodegradation using a Lab-Scale Biofilter Inoculated with Pseudomonas Putida PTCC 1694

10.21203/rs.2.24116/v2 ◽

2020 ◽

Author(s):

Roohollah Ghasemi ◽

Farideh Golbabaei ◽

Mohammad Reza Pourmand ◽

Sasan Rezaei ◽

Mohammad Javad Jafari ◽

...

Keyword(s):

Pseudomonas Putida ◽

Reliable Method ◽

Test Results ◽

Batch Test ◽

Biodegradation Rate ◽

Native Strain ◽

Batch Tests ◽

Air Stream ◽

Volatile Organic ◽

Parallel Configuration

Abstract Biomanipulation is reliable method for treating volatile organic compounds (VOCs) in polluted air. The performances of two biofilters in the removal of toluene vapors from air stream were compared. Two identical biofilters designed in parallel configuration were operated in lab-scale for 20 days; one of them was filled by sterilized media (compost and wood charcoal 2:1 v/v) and another was filled by the same media inoculated with Pseudomonas putida PTCC 1694, as a native strain. Moreover, batch tests were performed to determine the biodegradation rate of toluene. The results showed that, in comparison with the sterilized BF (89% vs 58%), the inoculated BF could effectively eliminate toluene from air stream. The pressure drop across the inoculated BF and the sterilized BF were 0.66±0.28 and 0.47±0.27 mm water respectively. The batch test results showed that loss of toluene in the control bottles was greater than the blanks. Based on the experimental results, inoculated BFs can effectively treat toluene vapors from gaseous streams.

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