Contrasting vertical distribution between prokaryotes and fungi in different water masses on the Ninety-East Ridge, Southern Indian Ocean

Although the microbial diversity of the Indian Ocean has been extensively investigated,little is known about the community composition of microbes in the Southern Indian Ocean.In the present study,we divided 60 water column samples on the Ninety-East Ridge(NER)into fi ve water masses according to the temperature-salinity curves.We presented,for the fi rst time,a full description of the microbial biodiversity on NER through high-throughput amplicon sequencing approach,including bacteria,archaea,and fungi.We found that bacteria exhibited higher richness and diversity than archaea and fungi across the water masses on NER.More importantly,each water mass on NER featured distinct prokaryotic microbial communities,as indicated by the results of non-metric multidimensional scaling.In contrast,fungi were eurybathic across the water masses.Redundancy analysis results demonstrated that environmental factors might play a pivotal role in the formation and stability of prokaryotic communities in each water mass,especially that of archaea.In addition,indicator species might be used as fi ngerprints to identify corresponding water masses on NER.These results provide new insights into the vertical distribution,structure,and diversity of microorganisms on NER from the perspective of water mass.

TiO_(2)@palygorskite composite for the efficient remediation of oil spills via a dispersion-photodegradation synergy

Removing spilled oil from the water surface is critically important given that oil spill accidents are a common occurrence.In this study,TiO_(2)@Palygorskite composite prepared by a simple coprecipitation method was used for oil spill remediation via a dispersion-photodegradation synergy.Diesel could be efficiently dispersed into small oil droplets by TiO_(2)@Palygorskite.These dispersed droplets had an average diameter of 20-30µm and exhibited good time stability.The tight adsorption of TiO_(2)@Palygorskite on the surface of the droplets was observed in fluorescence and SEM images.As a particulate dispersant,the direct contact of TiO_(2)@Palygorskite with oil pollutants effectively enhanced the photodegradation efficiency of TiO_(2)for oil.During the photodegradation process,·O_(2)^(−)and•OH were detected by ESR and radical trapping experiments.The photodegradation efficiency of diesel by TiO_(2)@Palygorskite was enhanced by about 5 times compared with pure TiO_(2)under simulated sunlight irradiation.The establishment of this new dispersion-photodegradation synergistic remediation system provides a new direction for the development of marine oil spill remediation.

Highly Efficient Photocatalytic Remediation of Simulated Polycyclic Aromatic Hydrocarbons （PAHs） Contaminated Wastewater under Visible Light Irradiation by Graphene Oxide Enwrapped Ag3PO4 Composite

Effective removal of polycyclic aromatic hydrocarbons （PAHs） from wastewater before their discharge into the environment is an ever pressing requirement. In this study, for the first time, simulated PAHs contaminated wastewater was photocatalytically remediated with graphene oxide （GO） enwrapped silver phosphate as visible light-driven photocatalysts. The GO/Ag3PO4 photocatalysts exhibited superior photocatalytic activity and stability compared with pure Ag3PO4, g-C3N4 and TiO2 （P25）. The degradation efficiency of naphthalene, phenanthrene and pyrene could reach 49.7%, 100.0% and 77.9%, rspectively within 5 min irradiation. The apparent rate constants of photocatalytic degradation of 3 wt% GO/Ag3PO4 composRe photocatalyst were 0.14, 1.21 and 2.46 rain^-1 for naphthalene, phenanthrene and pyrene, respectively. They were about 1.8, 1.5 and 2.0 times higher than that of pure Ag3PO4, and much higher than that of g-C3N4 and TiO2. Meanwhile, the efficiencies of 44.6%, 95.2% and 83.8% were achieved for naphthalene, phenanthrene and pyrene degradation even after 5 times of recycling in the GO/Ag3POa-PAHs photocatalysis system. Reactive species of O2^- and h^＋ were considered as the main partici- pants for oxidizing naphthalene, phenanthrene and pyrene.

Development of a new hydrophobic magnetic biochar for removing oil spills on the water surface

More technologies are urgently needed for combined use to effectively eliminate the effect of oil spills,an environmental problem of widespread concern.Among these technologies,sorption methods are available to remove residual oil and prevent the further spread on the water surface.In this study,biochars,prepared from different feed-stock materials and pyrolysis temperatures,were screened and further modified to improve their application in the water environment.Among cornstalk biochar(CSBC),corncob biochar(CCBC),Sophora sawdust biochar(SSBC),and rice husk biochar(RHBC),the CSBC had excellent oil sorption capacity,especially prepared at 350℃(CSBC350),which has a complete and full pore structure.Furthermore,magnetic and silane agent modifications of CSBC350(OMBC)were performed to enhance the properties of the magnetic field controllability and hydrophobicity to increase oil sorption.The OMBC exhibited satisfactory oil sorption capacities to crude oil,diesel oil,and engine oil in the water-oil system of 8.77 g g^(−1),4.01 g g^(−1),and 4.44 g g^(−1),respectively.The sorption process of CSBC350 and OMBC complied with the pseudo-second-order kinetics(R^(2)>0.97)and the Langmuir isotherm models(R^(2)>0.80)based on the highest regression coefficients.The sorption mechanisms are dominated by hydrophobic forces,pore intercepts,and hydrogenbond interactions.The biochar adsorbent can availably cooperate with other physical methods to eliminate oil contaminants,which can be an outstanding fuel source for producing heat.