Treatment of organic pollutants in coke plant wastewater by micro-nanometer catalytic ozonation, A/A/O and reverse osmosis membrane

Green synthesis and characterization of magnetite nanoparticles using Eucalyptus globulus leaves for water treatment and agronomic valorization

This work presents a new process, based on the green nanoparticles Fe3O4 and magnetization coupling for the treatment of saline well water. In this context, iron nanoparticles were synthesized using Eucalyptus globulus leaves. The nanomaterials were characterized by scanning electron microscopy and infrared for identification. Batch experiments were conducted to illustrate the optimal parameters related to contact times and the mass of nanoparticles. The latter marked an optimal contact time of 100 min and a mass of 56 mg/L accompanied by a magnetic treatment for a contact time of 48 min. The results showed a significant (R2 = 0.93) water salinity reduction (67%) and a potential for improvement in the germination of tomato seeds (81%) through the investigation of the evolution of the length of the roots, the stems, and the number of germinated seeds.

Determining the degradation mechanism and application potential of benzopyrene-degrading bacterium Acinetobacter XS-4 by screening

In industrial wastewater treatment, organic pollutants are usually removed by in-situ microorganisms and exogenous bactericides. Benzo [a] pyrene (BaP) is a typical persistent organic pollutant and difficult to be removed. In this study, a new strain of BaP degrading bacteria Acinetobacter XS-4 was obtained and the degradation rate was optimized by response surface method. The results showed that the degradation rate of BaP was 62.73% when pH= 8, substrate concentration was 10 mg/L, temperature was 25 °C, inoculation amount was 15% and culture rate was 180 r/min. Its degradation rate was better than that of the reported degrading bacteria. XS-4 is active in the degradation of BaP. BaP is degraded into phenanthrene by 3, 4-dioxygenase (α subunit and β subunit) in pathway Ⅰ and rapidly forms aldehydes, esters and alkanes. The pathway Ⅱ is realized by the action of salicylic acid hydroxylase. When sodium alginate and polyvinyl alcohol were added to the actual coking wastewater to immobilize XS-4, the degradation rate of BaP was 72.68% after 7 days, and the removal effect was better than that of single BaP wastewater (62.36%), which has the application potential. This study provides theoretical and technical support for microbial degradation of BaP in industrial wastewater.