Combined effects of microplastics and pharmaceutical and personal care products on algae: A critical review.

Microplastics (MPs) and pharmaceuticals and personal care products (PPCPs) are ubiquitous in aquatic environments. Algae play an important role in aquatic environments. Thus, it is important to study the response of algae to combined exposure of MPs and PPCPs. Here, we review the effects of MPs and PPCPs on algae. First, the individual effects of MPs and PPCPs on algae were summarized. Second, the combined effects of MPs and PPCPs on algae were systematically analyzed. (1) Antagonism: ① when the MPs are too large to enter the algal cells, the adsorption of PPCPs onto MPs results in decreased the contact of MPs and PPCPs with algae; ② PPCPs and MPs have opposing actions on the same biological target; ③ MPs increase the activity of metabolic enzymes in algae, thus promoting the PPCP degradation. (2) Synergy: ① when the MPs are small enough to enter algal cells, the adsorption of PPCPs on MPs promotes the entry of PPCPs; ② when MPs are negatively charged, the adsorption of positively charged PPCPs by MPs decreases the electrostatic repulsion, increasing the interaction between algae and MPs; ③ complementary modes of action between MPs and PPCPs show combined effects on the same biological target. Third, the relative importance of the factors that impact the combined effects are evaluated using the random forest model decreased in the following order: PPCP types > algal species > MP size > MP concentration > MP types > exposure time. Finally, future directions for the combined effects of MPs and PPCPs are proposed, which will facilitate a better understanding of the environmental fate and risks of both MPs and PPCPs.

Recent advances in microplastic removal from drinking water by coagulation: Removal mechanisms and influencing factors.

Microplastics (MPs) are emerging contaminants that are widely detected in drinking water and pose a potential risk to humans. Therefore, the MP removal from drinking water is a critical challenge. Recent studies have shown that MPs can be removed by coagulation. However, the coagulation removal of MPs from drinking water remains inadequately understood. Herein, the efficiency, mechanisms, and influencing factors of coagulation for removing MPs from drinking water are critically reviewed. First, the efficiency of MP removal by coagulation in drinking water treatment plants (DWTPs) and laboratories was comprehensively summarized, which indicated that coagulation plays an important role in MP removal from drinking water. The difference in removal effectiveness between the DWTPs and laboratory was mainly due to variations in treatment conditions and limitations of the detection techniques. Several dominant coagulation mechanisms for removing MPs and their research methods are thoroughly discussed. Charge neutralization is more relevant for small-sized MPs, whereas large-sized MPs are more dependent on adsorption bridging and sweeping. Furthermore, the factors influencing the efficiency of MP removal were jointly analyzed using meta-analysis and a random forest model. The meta-analysis was used to quantify the individual effects of each factor on coagulation removal efficiency by performing subgroup analysis. The random forest model quantified the relative importance of the influencing factors on removal efficiency, the results of which were ordered as follows: MPs shape > Coagulant type > Coagulant dosage > MPs concentration > MPs size > MPs type > pH. Finally, knowledge gaps and potential future directions are proposed. This review assists in the understanding of the coagulation removal of MPs, and provides novel insight into the challenges posed by MPs in drinking water.

Effect of phosphonate functional group on corrosion inhibition of imidazoline derivatives in acidic environment.

In the present study, ({2-[2-(7-Isopropyl-1,4-dimethyl-9,10-octahydro-phenanthren-1-yl)-4,5-dihydro-1-yl]-ethylamino}-methyl)-phosphonicimidazole (GSIM) was synthesized by introducing phosphonate (-PH2O3) group into imidazoline derivatives and its corrosion inhibition performance was studied for Q345 steel in acidic medium along with SIM using potentiodynamic polarization, EIS and SECM analysis. Surface analysis of steel samples was also performed by optical microscopy and SEM-EDS analysis after polarization tests. XPS was used to detect chemical composition of the surface passive films. It was observed that introducing -PH2O3 group not only improved the adsorption capacity on the metal surface by coordinating with iron ions, but also inhibited the interference of hydrogen bond formed by -NH2 group and water molecules on the adsorption. GSIM not only inhibited intercrystalline corrosion and pitting corrosion, but also reduced uniform corrosion. Thermodynamics studies demonstrated that GSIM followed the Langmuir adsorption isotherm and had a larger adsorption equilibrium constant than SIM, which indicated that it had a stronger adsorption capacity. XPS and UV confirmed that the coordination between GSIM and Fe3+ and hydrogen bonding between SIM and water molecules. The quantum chemical study further clarified that the site and strength of hydrogen bond between SIM and H2O and the dominant configuration and coordination stability of GSIM with Fe3+.