【摘 要】
：
External organic carbon sources are needed to provide electron donors for the denitrifica-tion of wastewater with a low COD/NO3-N (C/N) ratio,increasing the treatment cost.The economic strategy is to enhance the bioactivity and/or biodiversity of denitrif
【机 构】
：
Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education),School of
论文部分内容阅读
External organic carbon sources are needed to provide electron donors for the denitrifica-tion of wastewater with a low COD/NO3-N (C/N) ratio,increasing the treatment cost.The economic strategy is to enhance the bioactivity and/or biodiversity of denitrifiers to effi-ciently utilize organic substances in wastewater.In this study,novel zero-valent iron (ZVI)composite carriers were prepared and implemented in a suspended carrier biofilm reactor to enhance the bioactivity and/or biodiversity of denitrifiers.At the influent C/N ratio of 4 (COD was 179.5 ± 5.0 mg/L and TN was 44.2 ± 0.8 mg/L),COD and TN removal efficiencies were 85.1％ and 66.4％,respectively,in the reactors filled with 3 wt％ ZVI composite carriers.In contrast,COD and TN removal efficiencies were 70.4％ and 55.3％,respectively,in the reactor filled with conventional high-density polyethylene (HDPE) biofilm carriers.The biofilm for-marion on the 3 wt％ ZVI composite carriers was optimized due to its higher roughness (sur-face square roughness increased from 76.0 nm to 93.8 nm) and favorable hydrophilicity (wa-ter contact angle dropped to 72.5° ± 1.4° from 94.3° ± 3.2°) compared with the H-DPE biofilm carriers.In addition,heterotrophic denitrifiers,Thauera and Dechloromonas,were enriched,whereas autotrophic denitrifiers,Raoultella and Thiobaeillus,exhibited high relative abun-dance in the biofilm of ZVI composite carriers.The coexistence of heterotrophic denitrifiers and autotrophic denitrifiers on the surface of ZVI composite carriers provided mixotrophic metabolism of denitrification (including heterotrophic and iron-based autotrophic),thereby ensuring effective denitrification for wastewater with a low C/N ratio without external or-ganic carbon source addition.
其他文献
Recent studies show that triclosan (TCS) exposure causes reduction in pigments,suppres-sion of photosynthesis,and induction of oxidative stress at the physiological level,resulting in morphological alteration and growth inhibition in algae including Raphi
Urbanization often exerts multiple effects on aquatic and terrestrial organisms,including changes in biodiversity,species composition and ecosystem functions.However,the im-pacts of urbanization on river phytoplankton in subtropical urbanizing watersheds
Arsenic (As) and antimony (Sb) are usually coexistent in mine wastes and pose a great threat to human health.The As immobilization by nano zero-valent iron (nZVI) is promising,how-ever,the stabilization for co-occurring As and Sb is not known.Herein,the i
This study investigated concentrations of PM2.5,PM10,SO2,NO2,CO and O3,and air quality index (AQI) values across 368 cities in mainland China during 2015-2018.The study further examined relationships of air pollution status with local industrial capacitie
Airborne fine particulate matter (PM2.5) is known to cause respiratory inflammation such as chronic obstructive pulmonary disease and lung fibrosis.NLRP3 inflammasome acti-vation has been implicated in these diseases;however,due to the complexity in PM2.5
The brown mussel Perna perna (Linnaeus,1758) is a valuable resource for aquaculture in trop-ical and subtropical coastal regions.It presents desirable characteristics for biomonitoring,including being sessile,widely distributed and abundant,and is a filte
With increasing pressure from anthropogenic activity in pristine environments,the com-prehensive profiling of antibiotic resistance genes (ARGs) is essential to evaluate the poten-tial risks from human-induced antibiotic resistance in these under-studied
Heavy metal (Cu,Mn,Zn,Pb,and Cd) concentrations were measured in the leaves of Sabina chinensis and Platycladus orientalis collected from urban,suburban,and rural sites in Tianjin,China.Photosynthetic pigment contents,reactive oxygen species content,malon
Arsenic (As) contamination poses an urgent environmental risk,and its removal from groundwater remains a challenge due to the lack of efficient adsorbents.Herein,a novel granular chitosan-titanium (CS-Ti) adsorbent was fabricated by the sol-gel method.Bat
High loads of ground-level ozone have occurred with the implementation of the Air Poilu-tion Prevention and Control Action Plan.However,the long temporal variation in precursor nonmethane hydrocarbons (NMHCs) has rarely been studied.In this study,we exami