Biodegradability test

Tests for biodegradation are used to predict how quickly and completely hydrocarbons will break down in the environment. However, these tests can underestimate a chemical s ability to biodegrade if they do not examine real-world factors, such as the effects of waste water treatment or microorganism acclimation. Because biodegradability is widely recognized as an indicator of environmental safety, it is critical that realistic test conditions be used to determine biodegradability. 

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There have been numerous communications on the subject of biodegradation test methods, including aerobic compost (30), anaerobic bioreactor (31), general methodology and future directions (32—34), and a fine review article (24). ASTM (22) and MITI (35) have also set forth standard testing protocols for plastics, as shown in Table 2, whereas OECD test methods (29) are more suited to water-soluble polymers. 

De Morsier A, J Blok, P Gerike, L Reynolds, H Wellens, WJ Bontinck (1987) Biodegradation tests for poorly-soluble compounds. Chemosphere 16 269-277. 

Howard PH, S Banerjee (1984) Interpreting results from biodegradability tests of ehemicals in water and soil. Environ Toxicol Chem 3 551-562... 

Strotmann U, P Renschenbach, H Schwarz, U Pagga (2004) Development and evaluation of an online COj evolntion test and a multicomponent biodegradation test system. Appl Environ Microbiol 70 4621-4628. 

M. Mulyono, E. Jasjfi, and M. Maloringan. Biodegradation test for oil spill dispersant (OSD) and OSD-oil mixture. In Proceedings Volume, pages 355-363. 5th Asian Counc Petrol Conf (Ascope 93) (Bangkok, Thailand, 11/2-11/6), 1993. 

Pagga U, Brown D (1986) The degradation of dyestuffs part II. behaviour of dyestuffs in aerobic biodegradation tests. Chemosphere 15 479 -91... 

Table 1 also indicates that some FMs, including the PCMs and NMs, do not pass ready or inherent biodegradation tests. However, this does not mean that these FMs do not undergo biotransformation to polar metabolites under realistic conditions. These realistic biodegradation tests may be conducted in vitro, in bench-top die-away studies, or as continuous activated sludge and porous pot tests. Ideally, the conditions should include (1) realistic FM concentrations... 

It is expected that the final conversion of C4-glucamide acid occurs as an intracellular process. This assumption is supported by the findings of Stalmans et al. [131], in which high DOC removal and CO2 formation in standardised biodegradation tests was described. 

Generally, LAS biodegradation processes were previously monitored either as primary biodegradation (a decreasing LAS concentration) or as mineralisation (formation of biomass and/or C02). Both processes have usually been fitted to a first order kinetics, but this approximation is only valid if there has been no prior acclimatisation phase an initial lag phase is usually present in biodegradation tests [4]. Nevertheless, first order kinetic constants may be used for special cases or for a preliminary characterisation of the process. 

Fig. 5.3.3. HPLC chromatograms obtained during a C12-LAS biodegradation test, showing the typical sequence of SPC detected in this process (from Ref. [21]).

Zee, M.E. van der, Stoutjesdijk, J.H., Fell, H. and Feijen, J. (1998b). Relevance of aquatic biodegradation tests for predicting degradation of polymeric materials during biological waste treatment. Chemosphere, 36(3), 461 73. 

Norway has a standardized test program for permit derivation, comprising the Ames mutagenicity test, acute and chronic toxicity tests, and a biodegradation test. For monitoring purposes, it is advised to start screening the toxicity of an effluent with a comparatively large... 

Simple or automated offline or online biodegradability tests can be performed by measuring CO2 or CH4 gas production or O2 consumption [13]. Biosensors may utilize either whole bacterial cells or enzymes to detect specific molecules of hazardous substances. Toxicity can be monitored specifically by whole-cell sensors whose bioluminescence may be inhibited by the... 

Reuschenbach, P. Pagga, U. Strotmann, U. A critical comparison of respirometric biodegradation tests based on OECD 301 and related test methods. Water Res. 2003, 37, 1571-1582. 

Young, J.C. Affleck, S.B. Long-term biodegradability tests of organic industrial wastes. Proceeding of the 29th Industrial Waste Conference, Purdue University, West Lafayette, IN, 1974 26. 

Soil biodegradation tests were done by taking a sandy loam as the source of the soil micro-organisms. All polymer samples were sieved through ASTM sieves and all the samples except poly-e-caprolactone, had a particle diameter between 90 and 53 pm, Poly-e-caprolactone sample was prepared dissolving a commercially... 

By comparing the results from the biodegradation tests with those obtained from the study of chemical hydrolysis, it is obvious that a simple correlation between the two does not exist. 

Biodegradation tests have shown that surfactants containing a carbonate bond between the hydrophobic tail and the polar head group are readily biodegradable. In comparative tests such carbonate surfactants biodegrade somewhat faster than the corresponding surfactants containing an ester bond [35]. The carbonate bond is not only susceptible to alkaline hydrolysis... 

Waggy GT, Conway RA, Hansen JL, et al. 1994. Comparison of 20-d BOD and OECD closed-bottle biodegradation tests. Environ Toxieol Chem 13 1277-1280. 

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