biodegradation Articles
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Wastewater COD fractionation in the biological wastewater treatment
Biodegradable (bCOD) Consists of the total fraction from COD that can be biodegradated by the heterotrophic microorganisms. Readily biodegradable (rbCOD, SS) Consists of small molecules that are directly available for biodegradation by heterotrophic microorganisms. Slowly biodegradable (sbCOD, XS) Consists of larger molecules requiring extracellular breakdown (hydrolysis) before being ...
By SURCIS, S.L.
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Evaluation of the effects of nanoscale zero-valent iron (nZVI) dispersants on intrinsic biodegradation of trichloroethylene (TCE)
In this study, the biodegradability of nanoscale zero-valent iron (nZVI) dispersants and their effects on the intrinsic biodegradation of trichloroethylene (TCE) were evaluated. Results of a microcosm study show that the biodegradability of three dispersants followed the sequence of: polyvinyl alcohol-co-vinyl acetate-co-itaconic acid (PV3A) > polyoxyethylene (20) sorbitan monolaurate ...
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Biodegradation in oils as a geological natural analogue
A synthesis of scientific knowledge about petroleum biodegradation linked to uranium mineralisation is firstly done. Then the genesis of Huemul Uranium ore deposit (Malargüe Town, Mendoza Province) is discussed, where Uranium ore is linked only with one type of asphaltite (there are three other types) from an oil field close by. This asphaltite type would be an efficient natural geological ...
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BM Respirometry System for essential COD fractionation in wastewater
Wastewater characterization is nowadays considered an indispensable step that provides all the necessary information for a reliable management and design of biological treatment processes. This characterization should mainly include the chemical oxygen demand (COD) fractionation as an indispensable tool for all that. COD fractionation involves identification of non-biodegradable and ...
By SURCIS, S.L.
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Size-dependent microbial substrate uptake kinetics for aerobic granules
Biodegradation kinetics of aerobic granules determined by indirect method of resporimetric technique showed that it followed Monod kinetics, and the kinetic behaviour was size-dependent. It was further demonstrated that biodegradation kinetics was a surface reaction associated phenomenon. It shows that the affinity coefficient of biomass to substrate in terms of qmax/Ks ratio (specific maximum ...
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Biosorption and biodegradation of trichloroethylene by acclimated activated sludge
The biosorprion and biodegradation of trichloroethylene (TCE) was investigated. The experimental results showed that at 25°C the adsorption equilibrium of TCE at concentrations from 10 mg/L to 200 mg/L could be described by the Freundlich isotherm. Adsorption could complete within 15 min. Results indicated that glucose could serve as a co-substrate and enhance TCE biodegradation through ...
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Modeling ready biodegradability of fragrance materials
In the present study, Quantitative Structure Activity Relationships were developed for predicting ready biodegradability of approximately 200 heterogeneous fragrance materials. Two classification methods, Classification And Regression Tree (CART) and k‐Nearest Neighbors (k‐NN), were applied to perform the modeling. The models were validated with multiple external prediction sets, and the ...
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Immobilisation of TiO2 for combined photocatalytic-biological azo dye degradation
The biodegradability of the azo dye Remazol Red RR (100 mg/l) was evaluated using unadapted activated sludge and the experiment confirmed the recalcitrance of the dye. Using a combination of photocatalysis and an aerobic biological step, the biodegradability was improved significantly and complete removal of both colour and COD were achieved. Furthermore, TiO2 was successfully immobilised on ...
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Biodegradability of substances discharged to the aquatic environment
The term "biodegradability" is much used today, when most people, due to media exposure, are aware of the "environment" and "pollution". To say that a product or substance is "biodegradable" infers to the layman that it is ecologically "safe". Certainly it is safer than substances that contain persistent toxins (e.g. some pesticides, chlorinated hydrocarbons, tributyl tin, heavy metals etc). ...
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Hydrodynamics and batch biodegradation of phenol in an Internal Loop Airlift Reactor
Determination of Residence Time Distribution (RTD), oxygen volumetric mass transfer coefficient (kLa) and mixing pattern in an Internal Loop Airlift Reactor (ILALR) for both living and nonliving systems have been investigated in this paper. Optimal operating condition is found at a gas flow rate of 2 l min−1. The estimated kLa values for nonliving and living system at 27°C are 0.004 ...
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Biodegradable polyethylene
It is universally recognised that polyethylene (PE) is bio-inert. Indeed, conventional LDPE is used as a standard for bio-inertness in biodegradability/compostability test methods. It is not biodegradable because it is hydrophobic and because it consists of molecules having a high molar mass. Nevertheless it is a marvellous source of energy consisting entirely of the elements carbon and hydrogen ...
By ORBIT e.V.
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New product launch - BPC Blue
We are thrilled to announce the global launch of BPC® Blue – the perfect tool for determining the biodegradability of materials. If you need to determine the biodegradability of a material, BPC® Blue is the ideal instrument for the job. With its 18 (or 9) channels, you can test multiple samples at once, saving time and cost. Setting up a test is quick and easy, taking only 2-3 ...
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The evaluation of benzene and phenol biodegradation kinetics by applying non-structured models
The biodegradation kinetics of the aromatic hydrocarbons benzene and phenol as single substrates and as a mixture were investigated through non-structured model analysis. The material balance equations involving the models of Monod and Andrews and representing the biodegradation kinetics of individual substrates in batch mode were numerically solved. Further, utilization of a benzene–phenol ...
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Characteristics of benzene, toluene and xylene gas removal by a biofilter using scoria
The biodegradation experiments of Benzene, Toluene and Xylene (BTX) by bacillus culture were carried out. In batch biodegradation experiments of binary mixtures, benzene degradation was inhibited by the presence of either toluene or xylene and toluene degradation was inhibited by the presence of either benzene or xylene. However, xylene degradation was stimulated when xylene was present in a ...
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Biodegradation of Bisphenol-A in aerobic membrane bioreactor sludge
Bisphenol-A (BPA) biodegradation was studied in a membrane bioreactor under aerobic conditions. The effects of the initial BPA concentration and initial chemical oxygen demand (COD) concentration on BPA biodegradation were investigated. The degradation process followed a first-order kinetic (more than 98% of BPA was removed) with a kinetic rate constant of 1.134 h−1 using an ...
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Prediction of Biodegradability from Chemical Structure: Modeling of Ready Biodegradation test DNA
Biodegradation data were collected and evaluated for 894 substances with widely varying chemical structures. All data were determined according to the Japanese Ministry of International Trade and Industry (MITI) I test protocol. The MITI I test is a screening test for ready biodegradability and has been described by Organization for Economic Cooperation and Development (OECD) test guideline 301 C ...
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Kinetic study of Reactive Black 5 degradation by Fe2+/S2O82− process via interactive model-based response surface methodology
This study aimed to kinetically discover optimal conditions on characteristics of Reactive Black 5 decolorization/degradation via ferrous (Fe2+)-activated potassium persulfate (PS). Monod-like kinetics and interactive model-based response surface methodology (RSM) were applied to fitting and predict optimize treatment. Biodegradability of the intermediates was also tested by shaking culture ...
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Biodegradable products enhance oil production case study
Kemira’s biodegradable products play an important role in oil production in the North Sea. When seawater is injected into the deposits to move oil toward the drill pipes, it comes into contact with a different type of water: the water under the seabed. These two types of water do not mix well, and the layers of scale that form as a result may damage pipelines and halt production. The ...
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Combination of hydrodechlorination and biodegradation for the abatement of chlorophenols
A method for abatement for chlorophenols (CPs) in contaminated water based on successive steps of catalytic hydrodechlorination (HDC) over Pd/C at ambient temperature and pressure, followed by aerobic biodegradation using yeast Candida tropicalis (C. tropicalis) was studied. The results showed that 4-chlorophenol (4-CP) and 2,4-dichlorophenol (2,4-DCP) could be easily and completely dechlorinated ...
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Relationship between biodegradation and sorption of phthalate esters and their metabolites in natural sediments
Regulatory evaluations of commercial chemicals in Canada, the United States, the European Union, and other countries aim to identify biodegradation rates of chemicals in natural soils and sediments. However, commonly used biodegradation testing methods are limited in their capacity to determine biodegradation rates under natural environmental conditions. As a result, widely varying biodegradation ...
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