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The preliminary antitumor activity of the complex was also studied.

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A Co/Ti electrode for nitrate reduction was prepared by electrode-deposition. In the single-compartment electrolysis cell, nitrate (100 mg/L) removal reached nearly 100% after 3 h electrolysis under the current density of 20 mA cm–2 by using the Co/Ti electrode as cathode, and the main reduction products were ammonium nitrogen (66.5%) and nitrogen gas (33.5%). This performance on nitrate removal was comparable to a Co3O4/Ti electrode, and the electroactivity of the Co/Ti electrode towards nitrite reduction was higher than that of a Co3O4/Ti electrode. The Co/Ti electrode exhibited an improved stability with 18.7% of mass loss and 25.5% of Co dissolution compared with the Co3O4/Ti electrode after ultrasonic interference. The presence of chlorine ion (1,000 mg/L) could promote the total nitrogen (TN) removal to approximately 100% after 3 h electrolysis because of the ammonium oxidation by the free chlorine produced from the anode. In the presence of calcium (50 mg/L) and phosphate (0.5 mg/L), the nitrate removal decreased from 85.4 ± 1.5 to 57.7 ± 3.5% after ten reuse cycles. This result suggests that Ca and P should be pre-removed before the electro-reduction of nitrate.

Previous research has focused on the removal characteristics of inorganic nitrogen in the integrated fixed-film activated sludge (IFAS) process. However, information on dissolved organic nitrogen (DON) is scarce, even though DON can be an important form of nitrogen in wastewater treatment plants with low-effluent total nitrogen. This study investigated the removal characteristics of DON in IFAS with three frequently used carrier filling ratios (FRs = 20%, 30%, and 40%). The results showed that effluent DON significantly decreased with an increase in the FR (p < 0.05, t-test). DON hydrophobicity-based fractionation combined with DON molecular composition analysis indicated that effluent DON from IFAS at FRs of 20% and 40% exhibits more lability than that at an FR of 30%, indicating that effluent DON at FRs of 20% and 40% is more prone to stimulate algae. This finding was also supported by an algal bioassay. As a result, there was no bioavailable DON (ABDON) removal increase when the FR of IFAS increased from 30% to 40% (p = 0.925, t-test). Gray relational analysis revealed that the metabolites dihydroceramide, 1-hexanol, and 3-sulfinoalanine had the greatest influence on DON bioavailability. Overall, this study indicates that operating an IFAS process with a higher FR cannot control the DON forms that readily stimulate algal growth.