The Fenton-like process was established by Fe 3 O 4 nanomaterials (NMs) and Phanerochaete chrysosporium or oxalate, and applied to the co-composting of rice straw and sediment to study its effect on the formation of humic substance and the bioavailability of Cd, Cu, and Pb. Results shown that the application of Fenton-like process significantly promoted the passivation of Cd and Cu, while not shown obvious enhancement for Pb. The decrease of exchangeable fraction Cd (EXC-Cd) and the humic acid (HA) content in pile B with Fe 3 O 4 NMs and oxalate were highest, which were 22.35% and 20.3 g/kg, respectively. Redundancy analyses (RDA) manifested that the Fenton-like process enhanced the influence of humus substance on the bioavailability of Cd, Cu, and Pb. Excitation-emission matrix (EEM) fluorescence spectra analysis suggested that Fenton-like process could obviously enhance the generation of humic substance. This research provides a new perspective and way for composting to remediate heavy metals pollution.
Green Fe-Ce nanoparticles (GFC-NPs) synthesized in-situ by adding grape-seed extracts and Fe 2+ /Ce 3+ solution synchronously, were combined with H 2 O 2 for simultaneous enhancing sludge dewatering and phosphorus (P) recovery. GFC-NPs/H 2 O 2 (Fe/Ce molar ratio of 4:1) was demonstrated as a novel and efficient pretreatment even at pH 6.8 (without adjustment), where the values of specific resistance to filtration, Time to filtration and water content of mud cake were respectively decreased by 74.9 %, 47.0 % and 12.8 % under the optimal conditions of 30 mg (Fe+Ce) /g·TSS (total solid sludge), 100 mg H 2 O 2 /g·TSS, and reaction time 30 min. Meanwhile, excellent performances were also exhibited with above 95.9 % of P recovery in all investigated GFC-NPs/H 2 O 2 process. Compared with Fe 0 /H 2 O 2 or GF-NPs/H 2 O 2 , better performances were presented on both sludge dewaterability and P recovery after GFC-NPs/H 2 O 2 pretreatment. The Fe-Ce bimetallic catalysis significantly facilitated ·OH production (0.92 times higher than that of Fe 0 /H 2 O 2 ) and P could be recovered in the sludge simultaneously. Under GFC-NPs/H 2 O 2 oxidation, the larger reduction of PN and PS was examined in the LB-EPS and TB-EPS, as well as sludge particle size and the absolute value of zeta potential. Further analysis verified that GFC-NPs/H 2 O 2 oxidation could induce the looser conformation of protein secondary structure and cause the more release of bound water. In summary, GFC-NPs/H 2 O 2 is an eco-friendly and practical technology for enhancing sludge dewaterability and P recovery simultaneously.
危险品化学品经营许可证（带存储）