Data-driven systematic analysis of waterborne viruses and health risks during the wastewater reclamation process

Waterborne viral epidemics are a major threat to public health.Increasing interest in wastewater reclamation highlights the importance of understanding the health risks associated with potential microbial hazards,particularly for reused water in direct contact with humans.This study focused on identifying viral epidemic patterns in municipal wastewater reused for recreational applications based on long-term,spatially explicit global literature data during 2000e2021,and modelled human health risks from multiple exposure pathways using a well-established quantitative microbial risk assessment methodology.Global median viral loads in municipal wastewater ranged from 7.92×10^(4)to 1.4×10^(6)GC L^(-1)in the following ascending order:human adenovirus(HAdV),norovirus(NoV)GII,enterovirus(EV),NoV GI,rotavirus(RV),and severe acute respiratory syndrome coronavirus 2(SARSCoV-2).Following secondary or tertiary wastewater treatment,NoV GI,NoV GII,EV,and RV showed a relatively higher and more stable log reduction value with medians all above 0.8(84%),whereas SARSCoV-2 and HAdV showed a relatively lower reduction,with medians ranging from 0.33(53%)to 0.55(72%).A subsequent disinfection process effectively enhanced viral removal to over 0.89-log(87%).The predicted event probability of virus-related gastrointestinal illness and acute febrile respiratory illnesses in reclaimed recreational water exceeded the World Health Organization recommended recreational risk benchmark(5%and 1.9%,respectively).Overall,our results provided insights on health risks associated with reusing wastewater for recreational purposes and highlighted the need for establishing a regulatory framework ensuring the safety management of reclaimed waters.

Elucidating the role of P on Mn-and N-doped graphene catalysts in promoting oxygen reduction:Density functional theory studies

The non-noble Mn coordinated N,P co-doping graphene materials were investigated theoretically in this work based on density functional theory calculation.The electronic structure is effectively tuned after the introduction of P heteroatom.The moderate d band center and density of states at Fermi energy of MnN_(4)-P1-G indicate that it is ofmodest adsorption ability for these O-containing intermediates.The rank of adsorption energies ofO-containing intermediates for MnN_(4)-P1-G is OH*>2OH*>OOH*>O*>O2*>H2O*,whereas the MnN_(4)-P1-G favors a four-electron process instead of two-electron process.The doping of P on MnN_(4)-P1-G can increase the kinetic activity for the rate-determining step as well as the Ulim for MnN_(4)-P1-G significantly increases from 0.38 to 0.45 V compared with MnN_(4)-G.The spin density and magnetic moments of Mn are effectively tuned by d,p hybridization to lower the adsorption energy ofOHintermediates(rate-determining step[RDS])so as to improve the catalytic activity.It is concluded that the P-doped MnN_(4)catalysts with excellent oxygen reduction reaction activity can be obtained and this study can provide theoretical guidance for the rational design of high-performanceMn-based carbonmaterials catalysts.

Extracellular polymeric substances-antibiotics interaction in activated sludge:A review

Antibiotics,the most frequently prescribed drugs,have been widely applied to prevent or cure human and veterinary diseases and have undoubtedly led to massive releases into sewer networks and wastewater treatment systems,a hotspot where the occurrence and transformation of antibiotic resistance take place.Extracellular polymeric substances(EPS),biopolymers secreted via microbial activity,play an important role in cell adhesion,nutrient retention,and toxicity resistance.However,the potential roles of sludge EPS related to the resistance and removal of antibiotics are still unclear.This work summarizes the composition and physicochemical characteristics of state-of-the-art microbial EPS,highlights the critical role of EPS in antibiotics removal,evaluates their defense performances under different antibiotics exposures,and analyzes the typical factors that could affect the sorption and biotransformation behavior of antibiotics.Next,interactions between microbial EPS and antibiotic resistance genes are analyzed.Future perspectives,especially the engineering application of microbial EPS for antibiotics toxicity detection and defense,are also emphatically stressed.