Phthalocyanine blue leaching and exposure effects on Microcystis aeruginosa (cyanobacteria) of photoaged microplastics.

Light-stabilizing additives may contribute to the overall pollution load of microplastics (MPs) and potentially enter the food chain, severely threatening aquatic life and human health. This study investigated the variation between polystyrene (PS) MPs and phthalocyanine blue (CuPC)-containing MPs before and after photoaging, as well as their effects on Microcystis aeruginosa. The presence of PS-MPs increased cell mortality, antioxidant enzyme activity, and the variation in extracellular components, while the presence of CuPC exacerbated these variations. CuPC-containing MPs caused different increasing trends in superoxide dismutase and malondialdehyde activities due to electron transfer across the membrane. Transcriptomic analysis revealed that the MPs and CuPC affected various cellular processes, with the greatest impact being on cell membranes. Compared with MPs, CuPC negatively affected ribosome and polysaccharide formation. These findings provide insights into the molecular mechanisms underlying the cellular response to MPs and their associated light-stabilizer pollution and imply the necessity for mitigating the pollution of both MPs and light-stabilizers.

An Image Histogram Equalization Acceleration Method for Field-Programmable Gate Arrays Based on a Two-Dimensional Configurable Pipeline.

New artificial intelligence scenarios, such as high-precision online industrial detection, unmanned driving, etc., are constantly emerging and have resulted in an increasing demand for real-time image processing with high frame rates and low power consumption. Histogram equalization (HE) is a very effective and commonly used image preprocessing algorithm designed to improve the quality of image processing results. However, most existing HE acceleration methods, whether run on general-purpose CPUs or dedicated embedded systems, require further improvement in their frame rate to meet the needs of more complex scenarios. In this paper, we propose an HE acceleration method for FPGAs based on a two-dimensional configurable pipeline architecture. We first optimize the parallelizability of HE with a fully configurable two-dimensional pipeline architecture according to the principle of adapting the algorithm to the hardware, where one dimension can compute the cumulative histogram in parallel and the other dimension can process multiple inputs simultaneously. This optimization also helps in the construction of a simple architecture that achieves a higher frequency when implementing HE on FPGAs, which consist of configurable input units, calculation units, and output units. Finally, we optimize the pipeline and critical path of the calculation units. In the experiments, we deploy the optimized HE on a VCU118 test board and achieve a maximum frequency of 891 MHz (which is up to 22.6 times more acceleration than CPU implementations), as well as a frame rate of 1899 frames per second for 1080p images.

Electric-field enhanced microalgae inactivation using a flow-through copper ionization cell.

Using copper (Cu) to treat algal blooms is a commonly accepted method worldwide. However, the release of Cu may cause environmental and health risk. It is required to exploit an efficient way to reduce the Cu concentration but improve the algicidal effectiveness. Here, a Cu ionization cell (CIC) was designed and utilized in a flow-through system for inactivation of two bloom-forming microalgae species, Chlorella vulgaris and Microcystis aeruginosa. The results showed that the in-situ Cu release in the CIC treatment cause efficient microalgae inactivation. The 96 h-growth inhibition for C. vulgaris and M. aeruginosa reached 98.5 ± 3.1 % and 75.9 ± 2.0 % at a flow rate of 5 mL/min with the effluent Cu concentration of 554 ± 9 µg/L and 613 ± 17 µg/L, respectively. The maximum quantum yield (Fv/Fm) inhibitions of C. vulgaris and M. aeruginosa were 37.0 ± 1.6 % and 70.9 ± 2.1 %. The electric field enhanced CIC treatment has a locally higher Cu level because of the in-situ release. The CIC improved the microalgae inactivation performance by increasing the microalgae cell membrane permeability with excessive Cu uptake. The energy consumption was only 16.8 J/L. The in-situ Cu treatment in this work provides a microalgae inactivation method with the more environment-friendly and cost-effective prospect.

Effects of Fe3O4 nanoparticle fabrication and surface modification on Chlorella sp. harvesting efficiency.

Harvesting is a critical step in microalgae-based biodiesel production. Oleaginous microalgae harvesting by magnetic nanomaterials has gained attention because of the advantages of higher efficiency, lower cost, and convenient operation. In the present study, Fe3O4 magnetic nanoparticles (MNPs) were fabricated using two different methods (chemical coprecipitation and thermal decomposition), modified with amino acid using three different approaches (ultrasonic, long-time mixing, and "one-step" approaches), and utilized for oleaginous microalgae Chlorella sp. HQ harvesting. The results showed that the Fe3O4 MNPs synthesized by the chemical coprecipitation method achieved superior performance when considering both harvesting efficiency and fabrication cost. For the amino-acid modification, the one-step approach outcompeted the other approaches. At a dosage of 200 mg/L, the optimized Fe3O4@Arginine MNPs could achieve a harvesting efficiency of 95% with a low cost of only 347 USD/t of harvested algal biomass. Both the amino-acid content on the NPs and the number of amino groups in the amino acid molecules played a role in improving the harvesting performance.

Influences of carbon and nitrogen sources and metal ions on the heterotrophic culture of Scenedesmus sp. LX1.

In this study, the influences of organic carbon sources (OCS, including xylose, glucose, maltose, sucrose, and starch) and inorganic and organic nitrogen sources (INS, including ammonia chloride and sodium nitrate; ONS, including arginine, alanine, proline, and valine) and metal ions (including Na+, K+, Mn2+, Zn2+ and Cu2+) on the growth, lipid accumulation, and nitrogen and phosphorus (N&P) removal capabilities of oleaginous Scenedesmus sp. LX1 under heterotrophic conditions were investigated. The results showed that glucose was the only OCS for Scenedesmus sp. LX1 to grow well with specific growth rate of 0.935 days-1, maximum biomass of 1.72 g L-1, and largest removal rates of N&P and organic carbon reaching 72.228%, 93.034%, and 19.208%, respectively. After 11 days of cultivation, the maximal biomass reached in the group with starch or glucose while maximal lipid and triacylglycerol (TAG) yields reached in the groups with maltose and sucrose, respectively. Sodium nitrate was best nitrogen source as the largest algal density, maximal yields of lipids and TAGs, and highest N&P removal rates reached up to 1.105 × 107 cells·mL-1, 196.70 mg L-1, 5.19 mg L-1, 89.61% and 100%, respectively. Scenedesmus sp. LX1 was found to have great tolerance to Na+, K+, Mn2+, and Zn2+ while 0.5 mg L-1 Cu2+ had a strong inhibition on growth and N&P removal rate of Scenedesmus sp. LX1. Concentration increasing of five metal ions all caused the yield increases of microalgal lipid and TAGs. Graphical abstract.