Mechanisms of ZnO Nanoparticles Enhancing Phototransformation of Biologically Derived Organic Phosphorus in Aquatic Environments

Abstract

Zinc oxide nanoparticles (ZnO NPs), as the highly efficient photocatalysts, could enhance the transformation of biogenic organic phosphorus (OP) to orthophosphate (PO 4 3−) by photodegradation, accelerating eutrophication. Conversely, orthophosphate can also transform ZnO NPs and thus potentially alter their catalytic and chemical properties. Here, we investigated the transformation mechanisms of three biogenic OP compounds and ZnO NPs under ultraviolet light (UV) illumination: inositol phosphates (IHPs), nucleic acids (DNA), and aminoethylphosphonic acid (AEP). The physicochemical characteristics of the resulting products were systematically characterized. Results show that ZnO NPs accelerated the transformation of IHPs, DNA, and AEP to inorganic phosphorus with the direct photolysis efficiencies of 98.14, 87.68, and 51.76%, respectively. The main component of the precipitates remained ZnO NPs, and Zn 3 (PO 4 ) 2 was identified. Zinc phytate was determined in the ZnO NP−IHP system. 31 P NMR and FTIR further confirmed that the aquatic phase contained orthophosphate. Photoproduced hydroxyl (•OH) and superoxide (•O 2 − ) were proved to play a dominant role in the OP photomineralization. Furthermore, ZnO NPs significantly enhanced the intensity of •OH and •O 2 − compared to the OP and Zn 2+ solution alone. This work explored the light-induced mineralization processes of OP with ZnO NPs indicating that nanophotocatalysts may play a positive role in transformation of OP species in aquatic environments to further contribute to eutrophication.

Effects of Zinc Oxide Nanoparticles on Growth, Development, and Flavonoid Synthesis in Ginkgo biloba

“…Techniques such as TEM, XRD, and XPS are commonly used for the characterization of nanomaterials [28,29]. In this study, TEM, XRD, and XPS spectroscopic analyses showed that the size, properties, and structure of the purchased ZnO-NPs were consistent with previously reported findings (Figure 1) [30,31]. Therefore, these results indicate that the purchased materials possess…”

Efficient Treatment of Phosphonate-Laden Wastewater by CaO2/UV: Partial Oxidation, Complexation, and Coprecipitation

“…13−16 In water bodies, phosphonates can be slowly converted to phosphate through enzymatic or photochemical reactions. 17,18 Hence, phosphonates could be a potential source of bioavailable P. Indeed, Sisma-Ventura et al found that the discharge of polyphosphonate-containing desalination brine to coast areas stimulated microbial activity in the seabed. 19 Hasanin et al also reported that phosphonates significantly promote bacterial growth under phosphorus-limiting conditions, thus leading to membrane fouling when used as antiscalants.…”

“…However, it is important to note that phosphonates cannot be mineralized in WWTPs . Along with their widespread application yet poor degradation in WWTPs, phosphonates are frequently detected in sewage sludge, effluents of WWTPs, lakes, rivers, and oceans. − In water bodies, phosphonates can be slowly converted to phosphate through enzymatic or photochemical reactions. , Hence, phosphonates could be a potential source of bioavailable P. Indeed, Sisma-Ventura et al found that the discharge of polyphosphonate-containing desalination brine to coast areas stimulated microbial activity in the seabed . Hasanin et al also reported that phosphonates significantly promote bacterial growth under phosphorus-limiting conditions, thus leading to membrane fouling when used as antiscalants .…”

Deciphering the Impact of ZnO Nanoparticles and a Sunscreen Product Containing ZnO on Phosphorus Dynamics and Release in Chlorella pyrenoidosa in Aquatic Systems

“…8,9 In aquatic environments, ZnO NPs have been observed to accelerate the conversion of organic phosphorus (OP) to inorganic phosphorus (IP). 10 This transformation process may facilitate phosphorus (P) utilization by algae, consequently impacting algal growth.…”

“…Sun et al extracted ZnO nanoparticles (ZnO NPs) from commercially available sunscreens and demonstrated their efficacy as photocatalysts for degrading microplastics . ZnO NPs have been detected in aquatic environment at concentrations ranging from ng/L to mg/L, , posing potential risks to ecosystems and human health. , In aquatic environments, ZnO NPs have been observed to accelerate the conversion of organic phosphorus (OP) to inorganic phosphorus (IP) . This transformation process may facilitate phosphorus (P) utilization by algae, consequently impacting algal growth.…”