scholarly journals Rapid and Sensitive Detection of Water Toxicity Based on Photosynthetic Inhibition Effect

Toxics ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 321
Author(s):  
Min Chen ◽  
Gaofang Yin ◽  
Nanjing Zhao ◽  
Tingting Gan ◽  
Chun Feng ◽  
...  

To achieve rapid and sensitive detection of the toxicity of pollutants in the aquatic environment, a photosynthetic inhibition method with microalgae as the test organism and photosynthetic fluorescence parameters as the test endpoint was proposed. In this study, eight environmental pollutants were selected to act on the tested organism, Chlorella pyrenoidosa, including herbicides (diuron, atrazine), fungicides (fuberidazole), organic chemical raw materials (phenanthrene, phenol, p-benzoquinone), disinfectants (trichloroacetonitrile uric acid), and disinfection by-products (trichloroacetonitrile). The results showed that, in addition to specific PSII inhibitors (diuretic and atrazine), other types of pollutants could also quickly affect the photosynthetic system. The photosynthetic fluorescence parameters (Fv/Fm, Yield, α, and rP) could be used to detect the effects of pollutants on the photosynthetic system. Although the decay rate of the photosynthetic fluorescence parameters corresponding to the different pollutants was different, 1 h could be used as an appropriate toxicity exposure time. Moreover, the lowest respondent concentrations of photosynthetic fluorescence parameters to diuron, atrazine, fuberidazole, phenanthrene, P-benzoquinone, phenol, trichloroacetonitrile uric acid, and trichloroacetonitrile were 2 μg·L−1, 5 μg·L−1, 0.05 mg·L−1, 2 μg·L−1, 1.0 mg·L−1, 0.4 g·L−1, 0.1 mg·L−1, and 2.0 mg·L−1, respectively. Finally, diuron, atrazine, fuberidazole, and phenanthrene were selected for a comparison of their photosynthetic inhibition and growth inhibition. The results suggested that photosynthetic inhibition could overcome the time dependence of growth inhibition and shorten the toxic exposure time from more than 24 h to less than 1 h, or even a few minutes, while, the sensitivity of the toxicity test was not weakened. This study indicates that the photosynthetic inhibition method could be used for rapid detection of the toxicity of water pollutants and that algae fluorescence provides convenient access to toxicity data.

2021 ◽  
pp. 0734242X2110085
Author(s):  
Jabulani I Gumede ◽  
Buyiswa G Hlangothi ◽  
Chris D Woolard ◽  
Shanganyane P Hlangothi

There is a growing need to recover raw materials from waste due to increasing environmental concerns and the widely adopted transition to circular economy. For waste tyres, it is necessary to continuously develop methods and processes that can devulcanize rubber vulcanizates into rubber products with qualities and properties that can closely match those of the virgin rubber. Currently, the most common, due to its efficiency and perceived eco-friendliness in recovering raw rubber from waste rubbers, such as tyres, is devulcanization in supercritical carbon dioxide (scCO2) using commercial and typical devulcanizing agents. The scCO2 has been generally accepted as an attractive alternative to the traditional liquid-based devulcanization media because of the resultant devulcanized rubber has relatively better quality than other processes. For instance, when scCO2 is employed to recover rubber from waste tyres (e.g. truck tyres) and the recovered rubber is blended with virgin natural rubber (NR) in various compositions, the curing and mechanical properties of the blends closely match those of virgin NR. The atmospheric toxicity and cost of the commonly used devulcanization materials like chemical agents, oils and solvents have enabled a shift towards utilization of greener (mainly organic) and readily available devulcanization chemical components. This literature review paper discusses the approaches, which have less negative impact on the environment, in chemical devulcanization of rubber vulcanizates. A special focus has been on thermo-chemical devulcanization of waste tyres in scCO2 using common organic devulcanizing agents.


Author(s):  
M. Verma ◽  
Tania K. Naqvi ◽  
Santosh K. Tripathi ◽  
Manish M. Kulkarni ◽  
N. Eswara Prasad ◽  
...  

2019 ◽  
Vol 38 (2) ◽  
pp. 217-224 ◽  
Author(s):  
Yiran Yang ◽  
Yu Song ◽  
Xiangjie Bo ◽  
Jihong Min ◽  
On Shun Pak ◽  
...  

2019 ◽  
Vol 14 ◽  
pp. 545-552
Author(s):  
T. Dhanasekaran ◽  
A. Padmanaban ◽  
G. Gnanamoorthy ◽  
S. Praveen Kumar ◽  
A. Stephen ◽  
...  

2020 ◽  
Vol 31 (4) ◽  
pp. 3549-3556 ◽  
Author(s):  
Xinrui Guo ◽  
Hongyan Yue ◽  
Shuo Huang ◽  
Xin Gao ◽  
Yingyi Ma ◽  
...  

2017 ◽  
Vol 519 ◽  
pp. 92-99 ◽  
Author(s):  
Hong-wei Yu ◽  
Jing-hui Jiang ◽  
Ze Zhang ◽  
Guang-cai Wan ◽  
Zhi-yong Liu ◽  
...  

1979 ◽  
Vol 6 (2) ◽  
pp. 177 ◽  
Author(s):  
PM Gresshoff

The broad spectrum herbicide glyphosate inhibited growth of a bacterium (E. coli), an alga (Chlamydomonas reinhardi), plant cell cultures (carrot and soybean) and roots of whole plants (Arabidopsis thaliana). Inhibition was transitory, except in plant roots, suggesting breakdown of the herbicide by the test organism. Phenylalanine and tyrosine acted synergistically to reverse the growth inhibition. Addition of these alone, other amino acids and/or divalent metal ions (Fe2+, Co2+ , Zn2+) had no effect. The data are discussed in relation to a possible mode of action of glyphosate.


2018 ◽  
Vol 99 ◽  
pp. 519-524 ◽  
Author(s):  
Muhammad Saqib ◽  
Liming Qi ◽  
Pan Hui ◽  
Anaclet Nsabimana ◽  
Mohamed Ibrahim Halawa ◽  
...  

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