Contaminant biodegradation (round 2) papers, Page 2 Category

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https://ac.els-cdn.com/S1364032117314016/1-s2.0-S1364032117314016-main.pdf?_tid=a5eb2b14-7084-4bea-a3de-feeaee407262&acdnat=1521527455_bf79b1d62c6c400907b9240f7d5afd6c

SFazal, T., Mushtaq, A., Rehman, F., Khan, A. U., Rashid, N., Farooq, W., … & Xu, J. (2017). Bioremediation of textile wastewater and successive biodiesel production using microalgae.  Renewable and Sustainable Energy Reviews.

Microalgal biodiesel has emerged as an environment friendly alternative to the existing fossil fuels. The commercial production of this biodiesel is still challenging due to several technical and economic issues, which span from mass cultivation of microalgae to the biodiesel production. Mass cultivation is the most critical step in terms of water and nutrient requirement. Industrial wastewater such as textile wastewater (TWW) is a cheap source for water, which additionally contains necessary nutrients (phosphate, nitrates, micronutrients etc.) and organic dyes (potential carbon source) for algae cultivation. The application of microalgae for biodiesel production employing single objective strategy is not sustainable. Microalgae can be effectively employed to bioremediate TWW (dyes and nutrients removal) and to produce biodiesel from grown microalgae. This process integration (bioremediation-biodiesel production) can potentially improve biodiesel production and wastewater treatment. However, this process coupling needs to be thoroughly investigated to identify and optimize critical process factors (algal species, cultivation and harvesting methods, bioremediation mechanism etc.). This study has reviewed the status of TWW as potential source of water and nutrients, role of different algal species in the bioremediation of TWW, different cultivation systems, harvesting and biodiesel production methods. This review also suggests future research and development challenges for coupled textile wastewater treatment and microalgal biodiesel production.

Justification:

I thought this paper was really interesting! It talks about the biodegradation pathways involved in textile waste water and how the processes can be coupled with other biological processes. This paper discusses a rising problem in today’s world: fast fashion and the textile industry. I think it brings up important topics that address the sustainability of such a large and fast growing industry, and how microbes can potentially be utilized to mediate.

Abstract:

The manufacturing and use of pesticides has been rising tremendously in India. The waste generated by the pesticide industry has become an environmental problem due to the present insufficient and ineffective waste treatment technology involving physico-chemical and biological treatment. The available data indicates that pesticide residues remain in surface soil, leading to toxicity in the soilwater environment. The recent advances in bioremediation technology using microbial consortium has been found effective for treatment of pesticides in soil. In the present study, a Surface Soil Treatment Unit has been designed wherein bioremediation of commonly used pesticides namely chlorpyrifos, cypermethrin, fenvalerate, and trichlopyr butoxyethyl ester at varying concentration viz. 25, 50 and 100 mg/kg have been carried out using cow-dung microbial consortia under simulated environmental conditions. The bioremediation conditions have been monitored and maintained during the study. The investigation has been extended till the parent compound was converted into intermediates and/or less harmful compounds. These then will further mineralize, from part of the microbial food chain and/or become integrated into the humic fractions. The results presented here highlight the potential of cowdung slurry consortia for bioremediation of soil contaminated with pesticides in surface soil treatment unit.

Citation:

Geetha, M., & Fulekar, M. H. (2008). Bioremediation of pesticides in surface soil treatment unit using microbial consortia. African Journal of Environmental Science and Technology, 2(2), 036-045.

https://www.ajol.info/index.php/ajest/article/viewFile/135415/124907

I chose this article because I thought it was interesting that they took cow dung and used it’s natural microbial community to degrade certain pesticides. This could be very beneficial information for agricultural businesses. It could be a very affordable way to decrease concentrations of certain pesticides.

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Yang, H. S., Yoon, J. S., & Kim, M. N. (2004). Effects of storage of a mature compost on its potential for biodegradation of plastics. Polymer Degradation and Stability, 84(3), 411—417.

Link:  https://doi.org/10.1016/j.polymdegradstab.2004.01.014

Abstract

Biodegradation of plastics was tested in the compost stored at −20   °C, 4   °C and 20   °C for different periods. Viable cells in the compost stored at −20   °C were expected to be fewer than those in the compost stored at 4   °C and 20   °C, because microbes may be under stress or even be killed due to the formation of ice crystals at the subzero temperature. Mesophilic bacteria and mesophilic actinomycetes were fewer in number in the compost stored at 20   °C than in the compost stored at the other two lower temperatures contrary to expectation. In contrast, both thermophilic bacteria and thermophilic actinomycetes were fewest in the compost stored at −20   °C as was expected, indicating that thermophilic microbes were more susceptible to stress in the freezing conditions than the mesophilic ones. Activity of the exo-enzymes plausibly excreted by the microbes in the compost decreased as a result of the storage. Nevertheless, biodegradation of cellulose in the compost was almost independent of the storage time and temperature. In contrast, biodegradability of both polycaprolactone (PCL) and poly(butylene succinate) (PBS) depended strongly on the storage conditions. From the point of view that the existing standards for biodegradation tests of plastics in compost accept reproducibility of cellulose biodegradability as a criterion for the validity of the biodegradation tests, a new standard of the compost preparation should be provided to guarantee more reliable results on the biodegradability of plastics.

I thought this paper seemed interesting, mostly because I have never thought  of how compost could biodegrade plastic, and I thought it would be an interesting topic to learn more about, because of the large amount of plastic that we use nowadays.

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Considering the multiple sites around the greater Fairbanks area that have been found to have PFC contamination, I thought it would be of interest to learn  more about  the subject.  PFC’s are an emerging contaminant that do not readily biodegrade.

Abstract: The use of fluoride based foams increases the effectiveness of fire-fighting operations, but they are also accompanied by major drawbacks regarding environmental safety of perfluorinated compounds (PFCs). The main concern with PFCs release is due to their well-known persistence and bioaccumulative potential, as they have been detected in many environmental samples. There is a significant knowledge gap on PFC toxicity to plants, even though such data could be useful towards bioremediation procedures. It is consensus that a realistic assessment of fire-fighting foam toxicity should cover as many test organisms as possible, however, few studies combine the performance of ecotoxicological tests with a detailed study of microbial communities in soil contaminated with firefighting foams. Our research evaluated the effects of natural attenuation of PFCs on the development of arugula and lettuce seeds. The effects of variable PFCs amounts were also observed in soil microbiota using the 2,6 dichlorophenol-indophenol redox dye as microbial metabolism indicator. We aimed to determine whether aqueous film forming foams toxicity increased or decreased over time in a simulated contamination scenario. We argued that the long-term biotransformation of fire-fighting foams should be taken in to account when evaluating toxicity, focusing on a time-based monitoring analysis, since potentially toxic intermediates may be formed though biodegradation. The phyto-toxicity of PFCs to lettuce and arugula was high, increasing as a function of the concentration and decreasing as a function of exposure time to the environment. However, very specific concentrations throughout biodegradation result in the formation of non-inhibiting intermediates. Therefore, variable biodegradation-dependent germination rates may be misleading on non-time-based monitoring approaches. Also, the low phyto-toxicity after 240 days does not exclude the potential for PFC bioaccumulation in plants. We also proposed that the colorimetric data modelling could also establish a novel toxicity parameter to evaluate the release impacts to soil and biota. The combined assays allowed the monitoring of PFCs during long-term exposition to plants as well as their immediate effects on the same soil microbiota.

Citation: Renato Nallin Montagnolli, Paulo Renato Matos Lopes, Jaqueline Matos Cruz, Elis Marina Turini Claro, Gabriela Mercuri Quiterio, Ederio Dino Bidoia,
The effects of fluoride based fire-fighting foams on soil microbiota activity and plant growth during natural attenuation of perfluorinated compounds,
Environmental Toxicology and Pharmacology, Volume 50, 2017, Pages 119-127, ISSN 1382-6689, https://doi.org/10.1016/j.etap.2017.01.017.

Link: https://www.sciencedirect.com/science/article/pii/S138266891730025X

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