Migration Of Antibiotics Research Articles

Sorption and desorption behavior and mechanism of oxytetracycline on soil aggregates organic matter separated from soils and sediments in the Yellow River Delta

Soil aggregates organic matter (SAOM) is composed of free particulate organic matter (fPOM), intra-aggregate particulate organic matter (iPOM), and mineral-associated organic matter (mSOM), which are major antibiotic sorbents that play a significant role in the soil organic matter (SOM) turnover process. To date, the oxytetracycline (OTC) sorption and desorption behavior and mechanisms on SAOM have not been contrastively analyzed. SAOM organic components have been used to study scientific problems and to determine their influence on the fate and migration of OTC among the SOM turnover process. Results demonstrated that SAOM had great OTC sorption capacity ranging from approximately 12100–513,000 mg kg−1 and the desorption proportion was no more than 33.60%. The slow organic carbon pool (mSOM) had greater OTC accumulation capacity than the intermediate active pool (iPOM) and the active pool (fPOM), while OTC was more likely to reside in the active pool in wetlands (fPOM-w) and oil waste land (fPOM-o) than the organic carbon pool (mSOM-f) in farmland with human activity interference. The hysteresis was affected by SAOM's physical surface characteristics when the OTC initial equilibrium sorption concentration was higher than 200 mg L−1. When it was lower than that, it was affected by the organic carbon composition. Hydrogen bonds, electrostatic interactions, and π-π interactions dominated the SAOM-OTC interactions. The results of this study will be useful for evaluating the long-term behavior and migration of antibiotics in SOM turnover processes and could refine risk assessments of antibiotics contamination in soil environmental systems.

Influence of microplastics on the availability of antibiotics in soils

Microplastics (MPs) and antibiotics, as two major types of emerging pollutants, inevitably coexist in the soil environment due to agricultural film residue, sewage irrigation and sludge application. However, the impact of MPs on antibiotic availability in soils with varying characteristics has not been extensively studied. Therefore, in this study, an interference experiment was conducted using three types of MPs (polyethylene (PE), polyvinyl chloride (PVC) and polypropylene (PP)) in red soil, paddy soil and cinnamon soil. The available antibiotics in soils were evaluated using diffusive gradients in thin-films (DGT). Results showed that MPs had a significant impact on the amount of antibiotics adsorbed on soil solid (Cs) by providing additional binding sites or altering soil characteristics (e.g., pH and dissolved organic carbon). The most significant effects on Cs were observed in cinnamon soil, and the Cs values were dependent on concentration of MPs. The available antibiotics, as measured by DGT significantly decreased after the addition of MPs. This decrease was influenced by the soil characteristics. However, the concentration of antibiotics in soil solutions (Cd) was only slightly impacted by MPs. Therefore, the influence of MPs on the migration of antibiotics was reflected by their impact on the soil/water partition coefficient (Kd), while the resupply ability (R) from the soil solid phase was less influential. Moreover, the dosage of MPs had a significant effect on the availability of antibiotics in CS by promoting the adsorption of antibiotics on the solid phase, while in RS and PS, the soil properties played a dominate role in the changes in antibiotic availability after MP addition. These results indicate that the impact of MPs on available antibiotics mainly depends on soil properties. In addition, DGT measurement is more sensitive than soil solution to investigate the effects of coexisting pollutants on the behavior of antibiotics in soil.

Study of the adsorption behavior of tetracycline onto suspended sediments in the Yellow River, China: Insights into the transportation and mechanism

The increasing usage of household drugs has contributed to the widespread distribution of antibiotic pollutants in the aquatic environment. Although previous studies have proven that sediments could act as an important transport vector of antibiotic pollutants, the crucial impact of suspended sediments (SS) on the migration and fate of antibiotics in water bodies remains unclear. This study systematically investigated the performance and potential mechanism of adsorption of tetracycline (TC) on SS in the Yellow River. The results show that physisorption (pore filling, hydrogen bonding) and chemisorption (π-π interaction, surface complexation, and electrostatic interaction) activities contributed to the adsorption of TC onto SS. The mineral components (SiO2, Fe2O3, and Al2O3) of SS were found to be the main active sites for TC adsorption. The contribution of SiO2, Fe2O3, and Al2O3 to the overall TC adsorption could reach up to 5.6 %, 0.4 %, and 73.3 %, respectively. Interestingly, the DFT results suggesting that SiO2 tends to form intermolecular hydrogen bonds with TC, while Fe-O and Al-O play predominant roles in TC adsorption on SS. The MIKE simulations showed that river temperature, initial pH, and SS concentration would significantly affect the concentration of dissolved TC during SS transport. In addition, the presence of humic acid and more acidic environments favored the adsorption of TC on SS. Conversely, the introduction of inorganic cations inhibited the adsorption of TC on SS. This study provides new insights into the adsorption mechanism and migration of antibiotics in rivers with high SS content.

Antibiotics affected the bacterial community structure and diversity in pore water and sediments with cultivated Phragmites australis in a typical Chinese shallow lake.

The migration of antibiotics and bacterial communities between sediments and pore water occurring in the lake, which is affected by aquatic vegetation. However, the differences in bacterial community structure and biodiversity between pore water and sediments with plants in lakes under antibiotic stress are still poorly understood. We collected pore water and sediments in both wild and cultivated Phragmites australis regions in the Zaozhadian (ZZD) Lake to explore the characteristics of the bacterial community. Our results showed that the diversity of bacterial community in sediment samples were significantly higher than those in pore water samples in both P. australis regions. Due to higher antibiotic levels in sediments from the cultivated P. australis region, the composition of bacterial communities showed a difference, which reduced the relative abundance of dominant phyla in pore water and increased that in sediments. The higher bacterial variations in pore water could be explained by sediment in the cultivated P. australis region than that in wild P. australis region, therefore plant cultivation might change the source-sink pattern between sediments and pore water. The dominant factors shaping the bacterial communities in the wild P. australis region pore water or sediment were NH4-N, NO3-N, and particle size, while cultivated P. australis region pore water or sediment were oxytetracycline, tetracycline, etc. The findings of this work indicates that the antibiotic pollution caused by planting activities has a greater impact on the bacterial community, which will provide a reference for the use and management of antibiotics in lake ecosystems.

Simulation and risk assessment of typical antibiotics in the multi-media environment of the Yangtze River Estuary under tidal effect.

Frequent human activities in estuary areas lead to the release of a large number of antibiotics, which poses a great threat to human health. However, there are very limited studies about the influence of the special natural phenomena on the occurrence and migration of antibiotics in the environment. In this study, we simulated the migration and transformation of six typical antibiotics, including oxytetracycline (OTC), tetracycline (TC), norfloxacin (NOR), ofloxacin (OFX), erythromycin (ETM), and amoxicillin (AMOX), in the environmental media from 2011 to 2019 in the Yangtze River Estuary, by using the level III multi-media fugacity model combined with the factor of tides. The simulation results showed that the most antibiotics mainly existed in soil and sediment while erythromycin were found mainly in water. The concentrations of antibiotics in air, freshwater, seawater, groundwater, sediment, and soil were 10-23-10-25, 0.1-12ng/L, 0.02-7ng/L, 0.02-16ng/L, 0.1-13ng/g, and 0.1-15ng/g respectively. Sensitivity analysis showed that the degradation rate (Km) and the soil-to-water runoff coefficient (Kl) were important model parameters, indicating that hydrodynamic conditions had a significant impact on the migration of antibiotics in various environmental phases in estuarine areas. Tide can enhance the exchange between water bodies and cause the transformation of the antibiotics from freshwater to seawater and groundwater, which improved the accuracy of the model, especially the seawater and soil phase. Risk assessments showed that amoxicillin, erythromycin, ofloxacin, and norfloxacin posed a threat to the estuarine environment, but the current source of drinking water did not affect human health. Our findings suggested that, when one would like to exam the occurrence and migration of antibiotics in environment, more consideration should be given to the natural phenomena, in addition to human activities and the nature of antibiotics.

Multimedia fate model and risk assessment of typical antibiotics in the integrated demonstration zone of the Yangtze River Delta, China

Due to the widespread consumption of antibiotics by humans and animals, antibiotic residues from human and animal excrements are released into the environment through domestic sewage and breeding wastewater, which ultimately affect the ecological environment and human health. In this study, the concentrations of 10 antibiotics in the air, water, soil, and sediment from 2013 to 2019 in Qingpu District of the integrated demonstration zone of the Yangtze River Delta were predicated by developing a dynamic Level IV fugacity model. The influence of seasonal environmental factors (e.g., temperature, rainfall) on the distribution and migration of antibiotics in multi-media was also explored. The simulation results show that the 10 antibiotics mainly existed in water and sediment. The concentrations of antibiotics in air, water, soil, and sediment were 0–7.629 × 10−14 ng/L, 1.187 × 10−10-16.793 ng/L, 1.042 × 10−14-3.500 × 10−11 ng/g and 8.015 × 10−12-14.188 ng/g, respectively. It was also found that the increase in temperature and rainfall can reduce the migration rate of some antibiotics into the water and sediment phases. The flux analysis of the cross-media migration and transformation of antibiotics in Qingpu District shows that advection was the prime input and output paths of antibiotics in the water. Moreover, the prime input and output paths of antibiotics in sediment were sedimentation from water to sediment and degradation. Sensitivity analysis shows that the characteristics of antibiotic emission, degradation rate, and Koc were the most influential parameters for target chemicals. The results of risk assessment based on Monte Carlo method reveal that the overall risk level of antibiotics in sediment was relatively risk-free, and the risk of antibiotics in water decreased in the order of tetracyclines > β-lactams > fluoroquinolones > macrolides > sulfonamides.

Analysis of physicochemical factors regulating transport behaviors of sulfonamide antibiotics in saturated porous media

Sulfonamide antibiotics (SAs) are commonly used antibiotic classes in livestock worldwide. SAs are discharged to the environment and then may accumulate in rivers and aquifers, thereby diminishing water quality and the overall health of the ecosystem. While the occurrence and distribution of SAs in water environments have been the subject of numerous investigations, the fate and transport of SAs in aquifers have been less understood. In the present work, four of the most used SAs, including sulfadiazine (SDZ), sulfathiazole (STZ), sulfamethazine (SM2), and sulfamethoxazole (SMX), were selected for laboratory experiments and modeling analysis. The experiments were conducted in saturated columns filled with two common porous media, quartz sands and limestone grains. Results showed that the SAs had mobility changing on the order (from high to low) of SMX > SM2 > SDZ > STZ in the column, with SMX being the least absorbed SA by quartz sand or limestone grains. Moreover, calcium ionsinhibited the transport of SAs more strongly than that of sodium ions, while the inhibitory effect was slightly enhanced with an increasing Na+ concentration from 0 to 10 mM. In contrast, the presence of humic acid facilitated the transport of SAs. Although the four SAs have similar molecular structures, their adsorption and transport characteristics were shown to be quite different. The dynamics of the adsorption and transport of SAs in groundwater can be effectively described by a two-site adsorption model coupled with advection and dispersion. This study sheds new light on the transport of SAs, contributing to a better understanding of how to control the presence and migration of antibiotics as new emerging contaminants in groundwater.

Determination of veterinary pharmaceutical runoffs from a swine manure pile using LC\u2013MS/MS

The mass usage of veterinary pharmaceuticals in farms has contributed to environmental pollution in vicinity waters, soils, and sediments from farms and composting facilities. In the present study, we investigated the usage of four antibiotics (viz., lincomycin, sulfamethazine, sulfamethoxazole, and trimethoprim) to understand their contamination routes from livestock manure piles. Residual levels of these antibiotics in a nearby reservoir were set as a positive control (Site 1), and a swine manure pile in a farm (Site 2) and a soil sample around the manure pile (Site 3) were selected for this study. Artificial rainwater was flowed into the manure sample (Site 2), the soil sample around the manure pile (Site 3), and a soil sample around the vicinity river (Site 4). A stream sample (Site 5) around the manure pile and river water near the manure pile (Site 6) were also collected. For qualitative and quantitative analyses, analytical validation was performed, and all the four antibiotics were detected at Site 1 in the concentration range of 0.03–1.6 µg/L. Lincomycin was the antibiotic with the highest detection level. At Site 2, the detection level of all antibiotics remained at 0.3–17.3 µg/L, and their residual amounts were continuously detected in subsequent samples with approximately 30-fold decrease. The migration of antibiotics was confirmed to be independent of pH value. Therefore, this study indicates that farm manure pile should be thoroughly managed for antibiotic contamination in vicinity areas with periodical monitoring, especially waterways.

Migration of antibiotics in natural aquatic environment

The article is devoted to the analysis of available information about the migration of antibiotics in natural aquatic environment. Realizing the mechanism of drug release into the environment and into the aquatic environment will further develop protective measures and mechanisms to prevent appearing of antibiotic resistance genes in the aquatic environment. For example, in Russia during 2015 - 2016 only, for medical purposes 915.65 tons of antibiotics were used. It should be noted that the main danger of antibiotics is that they do not completely collapse and do not lose their original properties after ingestion, but almost completely retain their biological activity. It leads to the fact that the active molecule of the active substance is released unchanged during physiological secretions or through the skin and is able influence the environment.

Pollution characteristics and environmental risk assessment of typical veterinary antibiotics in livestock farms in Southeastern China

Scientific interest in pollution from antibiotics in animal husbandry has increased during recent years. However, there have been few studies on the vertical exposure characteristics of typical veterinary antibiotics in different exposure matrices from different livestock farms. This study explores the distribution and migration of antibiotics from feed to manure, from manure to soil, and from soil to vegetables, by investigating the exposure level of typical antibiotics in feed, manure, soil, vegetables, water, fish, and pork in livestock farms. A screening environmental risk assessment was conducted to identify the hazardous potential of veterinary antibiotics from livestock farms in southeast China. The results show that adding antibiotics to drinking water as well as the excessive use of antibiotic feed additives may become the major source of antibiotics pollution in livestock farms. Physical and chemical properties significantly affect the distribution and migration of various antibiotics from manure to soil and from soil to plant. Simple migration models can predict the accumulation of antibiotics in soil and plants. The environmental risk assessment results show that more attention should be paid to the terrestrial eco-risk of sulfadiazine, sulfamethazine, sulfamethoxazole, tetracycline, oxytetracycline, chlorotetracycline, ciprofloxacin, and enrofloxacin, and to the aquatic eco-risk of chlorotetracycline, ciprofloxacin, and enrofloxacin. This is the first systematic analysis of the vertical pollution characteristics of typical veterinary antibiotics in livestock farms in southeast China. It also identifies the ecological and human health risk of veterinary antibiotics.