Rapid aerobic granulation using biochar for the treatment of petroleum refinery wastewater

Aerobic granular sludge technology has great potential for the treatment of petroleum refinery wastewater.However,strategies to shorten the granulation time and improvement the stability still need to be developed.In this work,biochar was prepared from waste petroleum activated sludge(biochar-WPS) and used in a sequencing batch reactor for the treatment of petroleum refinery wastewater.Biochar-WPS presented the surface area of 229.77 m2/g,pore volume of 0.28 cm3/g,H/C and O/C atomic ratios of 0.42 and 0.21,respectively.The porous structure and a high degree of hydrophilicity were found to facilitate microbial colonization and adhesion as well as particle aggregation.Application of biochar-WPS resulted in the formation of more substantial and stable aerobic granules(~66% of granules> 0.46 mm diameter) 15 days earlier compared with the control.The addition of biochar-WPS enhanced the average removal efficiency of chemical organic demand(~3%),oil(~4%)and total nitrogen(~10%) over the control.Increased microbial richness and diversity were observed within the formed granules and had an increased(~4%) proportion of denitrifying bacteria.These results indicate that an aerobic granulation mechanism using biochar-WPS is a feasible option for the treatment of petroleum refinery wastewater.

Health risk ranking of antibiotic resistance genes in the Yangtze River

Antibiotic resistance is an escalating global health concern,exacerbated by the pervasive presence of antibiotic resistance genes(ARGs)in natural environments.The Yangtze River,the world's third-longest river,traversing areas with intense human activities,presents a unique ecosystem for studying the impact of these genes on human health.Here,we explored ARGs in the Yangtze River,examining 204 samples from six distinct habitats of approximately 6000 km of the river,including free-living and particle-associated settings,surface and bottom sediments,and surface and bottom bank soils.Employing shotgun sequencing,we generated an average of 13.69 Gb reads per sample.Our findings revealed a significantly higher abundance and diversity of ARGs in water-borne bacteria compared to other habitats.A notable pattern of resistome coalescence was observed within similar habitat types.In addition,we developed a framework for ranking the risk of ARG and a corresponding method for calculating the risk index.Applying them,we identified water-borne bacteria as the highest contributors to health risks,and noted an increase in ARG risks in particle-associated bacteria correlating with heightened anthropogenic activities.Further analysis using a weighted ARG risk index pinpointed the ChengdueChongqing and Yangtze River Delta urban agglomerations as regions of elevated health risk.These insights provide a critical new perspective on ARG health risk assessment,highlighting the urgent need for strategies to mitigate the impact of ARGs on human health and to preserve the ecological and economic sustainability of the Yangtze River for future human use.

Fungal-derived selenium nanoparticles and their potential applications in electroless silver coatings for preventing pin-tract infections

Pin-tract infections(PTIs)are a common complication of external fixation of fractures and current strategies for preventing PTIs have proven to be ineffective.Recent advances show that the use of anti-infection coatings with local antibacterial activity may solve this problem.Selenium has been considered as a promising anti-infection agent owing to its antibacterial and antibiofilm activities.In this study,selenium nanoparticles(SeNPs)were synthesized via a cost-effective fungi-mediated biorecovery approach and demonstrated excellent stability and homogeneity.To investigate their anti-infection potential,the SeNPs were doped in silver coatings through an electroless plating process and the silver–selenium(Ag–Se)coatings were tested for antibacterial and antibiofilm properties against Staphylococcus aureus F1557 and Escherichia coli WT F1693 as well as corrosion resistance in simulated body fluid.It was found that the Ag–Se coating significantly inhibited S.aureus growth and biofilm formation on the surface,reducing 81.2%and 59.7%of viable bacterial adhesion when compared with Ag and Ag–PTFE-coated surfaces after 3 days.The Ag–Se coating also exhibited improved corrosion resistance compared with the Ag coating,leading to a controlled release of Ag^(+),which in turn reduced the risk of cytotoxicity against hFOBs.These results suggest that the fungal-derived SeNPs may have potential in use as implant coatings to prevent PTIs.