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.

Adsorption behavior of sulfamethazine in an activated sludge process treating swine wastewater

Swine wastewater is an important pollution source of antibiotics entering the aquatic environment. In this work,the adsorption behavior of sulfamethazine（SMN）,a commonlyused sulfonamide antibiotic,on activated sludge from a sequencing batch reactor treating swine wastewater was investigated. The results show that the adsorption of SMN on activated sludge was an initially rapid process and reached equilibrium after 6 hr. The removal efficiency of SMN from the water phase increased with an increasing concentration of mixed liquor suspended solids,while the adsorbed concentration of SMN decreased. Solution pH influenced both the speciation of SMN and the surface properties of activated sludge,thus significantly impacting the adsorption process. A linear partition model could give a good fit for the equilibrium concentrations of SMN at the test temperatures（i.e.,10,20 and 30°C）. The partition coefficient（Kd） was determined to be 100.5 L/kg at 20°C,indicating a quite high adsorption capacity for SMN. Thermodynamic analysis revealed that SMN adsorption on activated sludge was an exothermic process. This study could help to clarify the fate and behavior of sulfonamide antibiotics in the activated sludge process and assess consequent environmental risks arising from sludge disposal as well.

Full-scale evaluation of reversed A^(2)/O process for removal of multiple pollutants in sewage

This study evaluated the removal of multiple pollutants,i.e.,polybrominated diphenyl ethers(PBDEs),novel halogenated flame retardants(HFRs),sulfonamide antibiotics(SAs),and heavy metals(HMs),by a fullscale reversed A^(2)/O process in a sewage treatment plant(STP)in Guangzhou,China.The reversed A^(2)/O process demonstrated high removal efficiencies(REs)for total PBDEs(60.5%±4.3%),novel HFRs(98.4%±2.8%)and HMs(70.1%±1.2%),and a relatively low RE for SAs(25.0%±2.3%).BDE 209,the dominant PBDE congener,showed a high residual concentration(13.41±5.18 ng/L)in the suspended particulate matter(SPM)of treated effluents.So me novel HFRs,dechlorane plus(DP)and decabromodiphe nyl ethane(DBDPE),were detected in the SPM of the raw sewage(7.50±4.14 ng/L and 11.52±11.65 ng/L,respectively).The removal ofSAs was mainly through biodegradation in the activated sludge bioreactors(ASBs).Ofthe HMs,Mn and Ni exhibited the lowest REs(47.5%±2.2%and 35.0%±2.6%,respectively),while Cr and Cu showed the highest removal(REs>80%).In terms of treatment units in the reversed A^(2)/O process,ASBs showed the highest RE(27.8%)for the multiple pollutants.The information can aid in our understanding of removal properties of STPs on various pollutants and evaluating the ecological/health risks of STPs as point pollutant sources.