Unraveling the dual roles of dissolved organic matter on the photodegradation of aquatic contaminants: Molecular weight- and type-dependent heterogeneities.

Dissolved organic matter (DOM) in natural waters can regulate the behaviors and fates of aquatic contaminants, while the specific effects on contaminant attenuation are highly dependent on its inherent properties [e.g., molecular weights (MW) and types].

Photo-methanification of aquatic dissolved organic matters with different origins under aerobic conditions: Non-negligible role of hydroxyl radicals.

Lingering inconsistencies in the global methane (CH) budget and ambiguity in CH sources and sinks triggered efforts to identify new CH formation pathways in natural ecosystems. Herein, we reported a novel mechanism of light-induced generation of hydroxyl radicals (•OH) that drove the production of CH from aquatic dissolved organic matters (DOMs) under ambient conditions. A total of five DOM samples with different origins were applied to examine their potential in photo-methanification production under aerobic conditions, presenting a wide range of CH production rates from 3.

Influences of dissolved organic matters on the adsorption and bioavailability of sulfadiazine: Molecular weight- and type-dependent heterogeneities.

The bioavailability of contaminants in aquatic environments was highly related with the existing forms (soluble or adsorbed) and properties of dissolved organic matters (DOMs). In this study, the molecular weight (MWs)-dependent effects of DOMs on the adsorption and bioavailability of sulfadiazine were explored. Colloid ZnO and AlO were employed as the representative colloidal particles, and algae-derived organic matter (AOM) and humic acid (HA) were selected as typical autochthonous and allochthonous DOMs.

Carbonized bacterial cellulose/FeMn composite as efficient catalyst toward contaminant degradation: The crucial role of hydrogen reduction.

The structure especially the active site manipulation of Fenton-like catalysts was essential for the efficient removal of organic contaminants in the aquatic environment. In this study, the carbonized bacterial cellulose/FeMn oxide composite (CBC@FeMnO) were synthetized and modified by hydrogen (H) reduction to obtain the carbonized bacterial cellulose/FeMn composite (CBC@FeMn), with emphasis on the processes and mechanisms for atrazine (ATZ) attenuation. The results showed that H reduction did not change the microscopic morphology of the composites but destroy the Fe-O and Mn-O structures.

Transforming heterotrophic to autotrophic denitrification process: Insights into microbial community, interspecific interaction and nitrogen metabolism.

For investigating the microbial community, interspecific interaction and nitrogen metabolism during the transform process from heterotrophic to synergistic and autotrophic denitrification, a filter was built, and carbon source and sulfur concentration were changed to release the transformation process. The results demonstrated that the transformation process was feasible to keep nitrate nitrogen (NO-N) discharge concentration lower than 15 mg L, however, nitrite nitrogen (NO-N) accumulation and its rate reached 7.85% at initial stages.