Phosphorus is a vital nutrient for algal growth, thus, a better understanding of phosphorus availability is essential to mitigate harmful algal blooms in lakes. Wind waves are a ubiquitous characteristic of lake ecosystems. However, its effects on the cycling of organic phosphorus and its usage by phytoplankton remain poorly elucidated in shallow eutrophic lakes. A mesocosm experiment was carried out to investigate the responses of alkaline phosphatase activity fractions to wind waves in large, shallow, eutrophic Lake Taihu. Results showed that wind-driven waves induced the release of alkaline phosphatase and phosphorus from the sediment, and dramatically enhanced phytoplanktonic alkaline phosphatase activity. However, compared to the calm conditions, bacterial and dissolved alkaline phosphatase activity decreased in wind-wave conditions. Consistently, the gene copies of Microcystis phoX increased but bacterial phoX decreased under wind-wave conditions. The ecological effects of these waves on phosphorus and phytoplankton likely accelerated the biogeochemical cycling of phosphorus and promoted phytoplankton production in Lake Taihu. This study provides an improved current understanding of phosphorus availability and the phosphorus strategies of plankton in shallow, eutrophic lakes. 相似文献
Water contamination by emerging organic pollutants is calling for advanced methods of remediation such as iron-activated sulfite-based advanced oxidation. Sulfate radical, SO4??, and hydroxyl radical, ?OH, are the primary reactive intermediates formed in the Fe(III)/sulfite system, yet the possible involvement of Fe(IV) produced from Fe(II) and persulfates is unclear. Here we explored the role of Fe(IV) in the Fe(III)/sulfite system by methyl phenyl sulfoxide (PMSO) probe assay, electron paramagnetic resonance spectra analysis, alcohol scavenging experiment, and kinetic simulation. Results show that PMSO is partially transformed into methyl phenyl sulfone (PMSO2), thus evidencing Fe(IV) formation. The remaining degradation of PMSO is due to SO4?? and ?OH. The contribution of Fe(IV) versus free radicals is progressively promoted when the Fe(III)-sulfite reaction proceeds, with an upper limit of 80–90%. The contribution of Fe(IV) versus free radicals increases with Fe(III) and sulfite dosages, and decreases with increasing pH. Overall, our findings demonstrate the involvement of Fe(IV) in the Fe-catalyzed sulfite auto-oxidation process.
Environmental Chemistry Letters - With the escalating food demand of the ever-increasing global population and the rapid development of nanotechnology, nanopesticides are being proposed as... 相似文献
Environmental Science and Pollution Research - Climate change and health are inextricably linked, especially the role of ambient temperature. This study aimed to analyze the non-communicable... 相似文献