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The contamination of the aquatic environment with microplastics has become a global environmental concern. Microplastic particles can be shredded to form smaller nanoplastics, and knowledge on their impacts on phytoplankton, especially freshwater microalgae, is still limited. To investigate this issue, the microalga Scenedesmus quadricauda was exposed to polystyrene nanoplastics (PS-NPs) of five concentrations (10, 25, 50, 100, and 200 mg/L). The growth; the contents of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD); the chlorophyll content; and concentrations of soluble protein and soluble polysaccharide were accordingly measured. The results showed that the microalgal density increased with the increase of the polystyrene nanoplastic concentrations, and the physiological features of alga were enhanced after the stimulation of nanoplastics. Furthermore, a high concentration (200 mg/L) of nanoplastics increased the contents of chlorophyll, soluble protein, and polysaccharide (P < 0.05). The antioxidant enzyme activities of Scenedesmus quadricauda were significantly activated by nanoplastics. Lastly, we propose three possible algal recovery mechanisms in response to nanoplastics in which Scenedesmus quadricauda was tolerant with PS-NPs by cell wall thickening, internalization, and aggregation. The results of this study contribute to understanding of the ecological risks of nanoplastics on freshwater microalgae., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Parachlorella kessleri TY isolated from the lawn soil belongs to Trebouxiophyceae, Chlorophyta. The complete mitogenome of P. kessleri sequenced and described. It is a circular duplex molecule 64,744 bp in length consisting of 28 protein-coding genes, 23 transfer RNA ( tRNA ) genes, four ribosomal RNA ( rRNA ) genes, and one putative open reading frames (ORFs). Phylogenetic analysis places P. kessleri mitogenome in a branch sister to Picochlorum sp ., Lobosphaera incisa , and Chloroparvula sp., clade in which Picochlorum as P. kessleri also reported as oil-rich green microalgae., Competing Interests: No potential conflict of interest was reported in the author(s)., (© 2021 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.)

Thorea hispida exclusively inhabits freshwater environments and is characterized by a triphasic life history. In this study, the organelle genomes and transcriptomes of different life history stages of T. hispida were examined using next generation sequencing. The chloroplast and mitochondrial genomes of the chantransia stage were 175,747 and 25,411 bp in length, respectively. The chantransia stage was highly similar to the gametophyte stage based on comparisons of organelle genomes and phylogenetic reconstruction. Transcriptomic comparisons of two stages found that ribosome-related genes were the most up-regulated in the gametophyte stage of T. hispida. Seven meiosis-specific genes, including SPO11 initiator of meiotic double-stranded breaks(spo11), meiotic nuclear divisions 1(mnd1), RAD51 recombinase(rad51), mutS homolog 4(msh4), mutS homolog 5(msh5), REC8 meiotic recombination protein(rec8), and DNA helicase Mer3(mer3), were differentially regulated between the two life history stages. The organelle genomes and transcriptomes from T. hispida provided in this study will be valuable for future studies of freshwater red algae., (Copyright © 2020 Elsevier Inc. All rights reserved.)

There is a concern about the increasing prevalence of health problems related to the ingestion of fluoride (F - ) in the developing world. Drinking water is one important source of F - , and the concentration of F - needs to be known to ensure the safety of drinking water. In this study, F - levels in drinking water were investigated across Taiyuan in Shanxi Province, China. Spatial-temporal distribution characteristics and potential associated health risks were analyzed using GIS. We collected 485 samples from shallow wells without any defluoridation treatments between 2008 and 2016. After analyzing the samples of F - content we found that mean F - levels of urban areas (0.61 ± 0.39 mg L -1 ), suburban areas (0.70 ± 0.87 mg L -1 ) and for all of Taiyuan city (0.63 ± 0.56 mg L -1 ) were in optimum range based on the recommendation by USEPA. However, individual locations within industrial areas (e.g. Gujiao District) had higher F - levels (1.06 mg L -1 ). A concerning result showed that 12.37% of tested locations had F - concentrations larger than 1.0 mg L -1 . We calculated F - Health Risk Indices (HRIs F ) and found that highest were associated with suburban areas, especially in the year 2009 and 2010. However, from 2008 to 2016, overall F - levels and HRIs F of the sampled groundwater in Taiyuan City showed a decreasing trend. HRIs F in suburban areas was higher than urban areas, possible due to the heavily prevalent coal mining industry in those areas. Specific policies should be formulated to address HRIs F ., (Copyright © 2018 Elsevier Inc. All rights reserved.)

The ability of the agricultural residue of Phragmites australis to serve as an absorbent material used to remove phenol from aqueous solutions in batch and continuous fixed-bed columns was investigated. Prepared adsorbents were characterized by SEM, FTIR, and pHpzc methods. The equilibrium adsorption (qe) of phenol was increased from 9.61 to 29.40 mg/g when the initial phenol concentrations increased from 50 to 150 mg/L. The max adsorption capacity of Phragmites australis was found to be 29.60 mg/g at 30 °C. In column studies, a higher flow rate, higher initial concentration of phenol, and shorter packing layer height increase the column adsorption capacity of phenol. In a batch and continuous fixed-bed column studies, the experiment data was evaluated by some classic models. Fitting degree between the experimental results shows that the pseudo-second-order adsorption kinetics and Langmuir model were the best. Thomas and Yoon-Nelson models were in good agreement with the experimental breakthrough curve data. Both batch and continuous investigation indicated that Phragmites australis could be used as a fine adsorbent to remove phenol and that the adsorption efficiency improved significantly in the column experiment.