Phosphine production in anaerobic wastewater treatment under tetracycline antibiotic pressure

The influence of tetracycline（TC） antibiotics on phosphine（PH3） production in the anaerobic wastewater treatment was studied. A lab-scale anaerobic baffled reactor with three compartments was employed to simulate this process. The reactor was operated in a TC-absence wastewater and 250 μg/L TC-presence wastewater for three months after a start-up period,respectively. The responses of p H, oxidation–reduction potential（ORP）, chemical oxygen demand（COD）, total phosphorus（TP）, enzymes activity（dehydrogenase and acid phosphatase）,and microbial community were investigated to reveal the effect of TC on PH3 production.Results suggested that the dehydrogenase（DH） activity, acid phosphatase（ACP） activity and COD have positive relationship with PH3 production, while p H, ORP level and the TP in liquid phase have negative relationship with PH3 production. With prolonged TC exposure, decrease in p H and increase in DH activity are beneficial to PH3 production, while decrease in COD and ACP activity are not the limiting factors for PH3 production.

A new Eu-MOF for ratiometrically fluorescent detection toward quinolone antibiotics and selective detection toward tetracycline antibiotics

Development of new self-calibrating fluorescent sensing methods has been a popular research field with the aim of protecting the human health and environment sustainability. In this work, a novel Eu-based metal organic framework(MOF) Eu(2,6-NDC)(COO)(BUC-88) was developed by employing 2,6-NDC(2,6-naphthalenedicarboxylic acid) as bridging ligands. BUC-88 performed different sensing process toward quinolone antibiotics and tetracyclines antibiotics in terms of fluorescence intensity and color. BUC-88exhibited excellent selectivity and sensitivity detection property toward enrofloxacin(ENR), norfloxacin(NOR) and ciprofloxacin(CIP) over other Pharmaceutical and Personal Care Products(PPCPs), accomplishing the detection limit of 0.12 μmol/L, 0.52 μmol/L, 0.75 μmol/L, respectively. Notably, BUC-88 acted as an excellent fluorescence sensor for tetracyclines antibiotics with fast response time(less than 1 s), high selectivity and sensitivity(LODs = 0.08 μmol/L). The fluorescent detection method was successfully used for visual and ultrasensitive detection of ENR, NOR, CIP and tetracycline hydrochloride(TC) in lake water with satisfied recovery from 99.75% to 102.30%. Finally, the photoinduced electron transfer and the competitive absorption of ultraviolet light are the main mechanisms for sensitive detection toward quinolone antibiotics and tetracyclines antibiotics.

Investigation on the Veterinary Antibiotics Contamination in Groundwater with SPE-LC/MS/MS

[Objective]The aim is to provide data support for the prevention and control of pollution of exogenous chemical in pig breeding industry.[Methods]Solid-phase extraction（SPE）and tandem mass（LC-MS/MS）were used for determining four classes（tetracyclines,quinolones,macrolides and sulfonamides）of 10 common veterinary antibiotics in groundwater of an important pig breeding base in the Yangtze River Delta region of China.[Results]Results revealed the total concentration of the ten antibiotics in urban rivers ranged from 20.1 ng /L to 61.2 ng /L.The highest proportion was taken by tetracyclines,account for 95%,the concentration was up to 44.0 ng /L.Quinolones shared the second largest proportion of total concentration,about 29%,the concentration was up to 21.6 ng /L,while concentration of sulfonamides and macrolides were respectively below 2.7 ng /L and 6.3 ng /L.The highest total concentration of the ten antibiotics in rural rivers was up to 467 ng /L,60% of which was shared by tetracyclines,the highest concentration of tetracyclines was 253 ng /L.Sulfonamides share 20% of the total concentration,the highest concentration of it was 165 ng /L.The highest concentration of macrolides and quinolones was 14.6 ng /L and 14.5 ng /L,respectively.[Conclusion] Antibiotics＇ pollution in town rivers is more serious than urban rivers＇ pollution caused by antibiotics.

Selective adsorption of tetracycline by b-CD-immobilized sodium alginate aerogel coupled with ultrafiltration for reclaimed water

In this work,a novel composite material based on b-cyclodextrin-immobilized sodium alginate aerogel(b-CD/NaAlg)was developed utilizing cross-linker of epichlorohydrin and applied as an adsorbent to remove tetracycline antibiotics from reclaimed wastewater.A series of characterizations were utilized to confirm the successful synthesis of the adsorbent and this b-CD/NaAlg presented a three-dimensional network at the nanoscale or microscale.Under optimal conditions(pH=4,t=8 h,b-CD:NaAlg=9,adsorbent dosage=1.5 g·L^(-1)),the maximum removal rate of b-CD/NaAlg to tetracycline was 70%.The adsorption behavior of tetracycline on b-CD/NaAlg conformed to the Freundlich isotherm model(R^(2)=0.9977)and the pseudo-second-order kinetic model(R^(2)=0.9993).Moreover,the adsorbent still removed 55.3%of tetracycline after five cycles.Specially,the adsorbent was integrated with ultrafiltration to adsorb tetracycline antibiotics from simulated reclaimed wastewater,and the removal rate of tetracycline reached 78.9%within 2 h.The existence of Cr(VI)had a negligible impact on tetracycline removal,while the presence of humic acid exhibited a promoting effect.The possible adsorption mechanisms were also elucidated through X-ray photoelectron spectroscopy and density functional theory analysis.In summary,b-CD/NaAlg represents an environmentally friendly,efficient,and sustainable adsorbent for removing tetracycline antibiotics from reclaimed water.

Two-dimensional Ti_(3)C_(2)T_(X)-nanosheets/Cu_(2)O composite as a high-performance photocatalyst for decomposition of tetracycline

Construction of photocatalysts with a Schottky heterojunction could realize highly efficient and stable degradation of organic pollutes in the wastewater.In this work,a precipitation method was used to prepare Ti_(3)C_(2)T_(X)-nanosheets/Cu_(2)O composite photocatalysts with the Schottky heterojunction for the decomposition of tetracycline(TC)antibiotics under visible light.As-prepared photocatalysts were characterized by various techniques such as X-ray diffraction analysis(XRD),High resolution transmission electron microscopy(TEM)and X-ray photoelectron spectroscopy(XPS).When the best Ti_(3)C_(2)T_(X)-nanosheets/Cu_(2)O composite was applied for the degradation of TC under visible light,the degradation efficiency reached up to 97.6%only in 50 min.It is considered that superoxide radical(O_(2)^(→))and hole(h^(+))were the main reactive species for the TC degradation,and in the Schottky heterojunction,e^(-)-h^(+)pairs in the catalyst could be transferred and separated effectively,resulting in obviously enhanced photocatalytic efficiency and stability.