RESUMO
High-solid anaerobic digestion (HSAD), as an emerging disposal technology for swine manure, was commonly hampered by the long lag phase and slow startup, resulting in poor performance. Rapid startups by different leachate reflux forms can solve the problem, but related study was scarcely reported. Therefore, metagenomic analysis was used to exploit the effects of different rapid startups on the biogas performance, antibiotic resistance genes (ARGs) removal and microbial metabolic pathway during HSAD. Compared anaerobic digestion with natural start (T1), three different rapid startups were set, including with autologous leachate reflux (T2), with water reflux (T3) and with exogenous leachate reflux (T4). The results showed that rapid startups (T2-T4) enhanced biogas yield and the cumulative methane yield was increased by 3.7-7.3 times compared with the control. Totally, 922 ARGs were found, most of which belonged to multidrug and MLS ARGs. About 56% of these ARGs could be reduced in T4, while just 32% of ARGs were reduced in T1. Antibiotic efflux pump is the main mechanism of microbial action, which could be decreased largely by these treatments. Moreover, all the rapid startups (T2-T4) made Methanosarcina content (9.59%-75.91%) higher than that in the natural startup of T1 (4.54%-40.27%). This is why these fast-startups helped methane production fast. Network analysis showed that microbial community and environmental factors (pH and VFAs) both contributed to the spread of ARGs. The reconstructed methane metabolic pathway by different identified genes showed that all methanogenesis pathways existed but acetate metabolic pathway was dominant. And the rapid startups made the abundance of acetate metabolic (M00357) higher than the natural startup.
Assuntos
Antibacterianos , Esterco , Suínos , Animais , Antibacterianos/farmacologia , Anaerobiose , Biocombustíveis , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos , Redes e Vias Metabólicas/genética , MetanoRESUMO
The present study firstly aimed at developing a multi-residue method to identify and quantify 38 veterinary antibiotics (belonging to five different classes) not only for raw swine wastewater but also for wastewater differently treated by different units. The proposed method is based on a solid-phase extraction procedure and ultra high performance liquid chromatography with mass spectrometry. For sample preparation, the optimal loading sample volume was selected as 50 mL, the pH of which was adjusted to approximately 3.0 using formic acid. Then 0.1 g/L ethylenediaminetetraacetic acid disodium salt was added. The recovery rates for different types of wastewaters were in the range of 35.94-124.51% and the relative standard deviations were in the range of 0.36-14.62%. All the matrix standard curves exhibited high linearity (0.9956-0.9999). The matrix effects for the target antibiotics ranged from -61.73 to +148.75%. To ensure the practicality of the method, we performed the detection of the actually added concentration to determine method detection limits and quantitation limits. The quantitation limits of most of the target antibiotics were 0.04 µg/L, except for spiramycin (0.1 µg/L) and roxithromycin (0.2 µg/L). This optimized and validated method was applied to analyze antibiotic residues in swine water samples from four swine farms.
Assuntos
Espectrometria de Massas em Tandem , Águas Residuárias , Animais , Antibacterianos/análise , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Fazendas , Extração em Fase Sólida , Suínos , Espectrometria de Massas em Tandem/métodos , Águas Residuárias/análiseRESUMO
Residue of veterinary antibiotics (VAs) in the animal breeding industry has become a problematic environmental issue. However, the residual levels of VAs as well as their variation tendency, degradation mechanisms and relationships with other parameters during animal wastewater disposal processes are still obscure. This study measured different samples during wastewater disposal processes from three farms, and systematically analyzed the residue, migration and removal of 58 kinds of typical VAs (6 classes) in Tianjin, China. The results showed that about 44 kinds of VAs were quantitatively detected. Tetracycline antibiotics (TCs) usually had higher residual concentrations than other classes of VAs in the raw wastewater; the highest residual concentration was 130.67⯱â¯5.90⯵g/L which occurred for chlortetracycline (CTC). Pig farms generally had more VAs species and higher residual concentrations than dairy farms, and the proportion of different VAs was similar for dairy farms. The final removal rates of different VAs classes varied largely (negative to >â¯99.87%), and the highest removal rates usually occurred in biological processes for adsorption and biodegradation effects, and occasionally occurred in the final effluents. The correlation coefficients between VAs removal rates and chemical oxygen demand (COD) removal rates were much higher than those of total nitrogen (TN), total phosphorus (TP) and ammonia nitrogen (NH4-N) in pig farms, while opposite conclusion was obtained in dairy farms. Among different classes, TCs presented the highest daily mass loading of NDâ¯~â¯10,453.8⯱â¯471.7â¯mg/d in the influent and NDâ¯~â¯1141.6⯱â¯58.9â¯mg/d in the effluent in farm 1.
Assuntos
Antibacterianos/análise , Águas Residuárias/química , Poluentes Químicos da Água/análise , Criação de Animais Domésticos , Animais , Biodegradação Ambiental , Análise da Demanda Biológica de Oxigênio , Bovinos , China , Indústria de Laticínios , Nitrogênio/análise , Fósforo/análise , Suínos , Drogas Veterinárias/análise , Eliminação de Resíduos Líquidos/métodosRESUMO
The MnO2-mullite-cordierite composite particle (MnO2-MCP) was prepared and firstly was applied as catalyst with sodium hypochlorite (NaOCl) as oxidant in heterogeneous Fenton-like system for methylene blue (MB) decolorization. The MnO2-MCP was characterized by XRD, SEM, EDS and BET analysis. The decolorization efficiencies of MB/MnO2-MCP, MB/NaClO, (MB after filtrating MnO2-MCP)/NaClO and MB/MnO2-MCP/NaClO were compared, which confirmed the interaction ability between MnO2-MCP and NaClO. After evaluating the role of adsorption of MB by MnO2-MCP, the catalytic oxidation effects of MnO2-MCP with NaClO on MB were exploited. The adsorption results showed that the new porous catalyst had certain adsorption capacity for MB and the adsorption fit best with Langmuir model. The central composite rotatable design (CCD) of response surface methodology (RSM) was used to design catalytic oxidation experiments of MB/MnO2-MCP/NaClO system, with influencing factors of catalyst dose, NaClO concentration, pH and initial MB concentration. The optimum conditions were 5.97â¯mM of NaClO, 37.9â¯g/L of catalyst dose, 5.74 of pH value and 100.71â¯mg/L of initial MB concentration, which could ensure nearly 100% MB decolorization. The effect of radical scavengers elucidated that superoxide anion (O2-) was the main species to decolorize MB. Then the possible degradation mechanism and pathway of MB were proposed in this MnO2-MCP/NaClO system.
Assuntos
Silicatos de Alumínio , Purificação da Água , Cerâmica , Concentração de Íons de Hidrogênio , Azul de Metileno/isolamento & purificaçãoRESUMO
Although the arsenic contamination and antibiotic resistance genes (ARGs) during composting have been studied separately, there is limited information on their interactions, particularly, the relationship between arsenic biotransformation genes (ABGs) and ARGs. Therefore, the present study used different forms of arsenic stress (organic and inorganic arsenic at 10 and 50 mg/kg) in pig manure and straw co-composting, to evaluate the effects of arsenic stress on microbial community structures, metabolic function, ABGs, and ARGs. The results showed that arsenic stress had different effects on different parameters and promoted the microbial formation of humic acid and the biodegradation of fulvic acid. Inorganic arsenic showed more rapid effects on microbial community structure, visible within about 20 days, while the effects of organic arsenic were later (about 45 days) due to the necessity of transformation. Moreover, the addition of organic roxarsone and inorganic arsenic resulted in higher expression of ABGs and ARGs, respectively. Arsenic addition also caused increased expression of genes associated with replication and repair. A significant relationship was observed between ABG and ARG expression, for instance, genes involved in arsenic reduction and oxidation were influenced by genes involved in aminoglycoside and chloramphenicol resistance genes (p < 0.05). These complex interactions among microorganisms, functional genes, and external parameters contribute to the understanding of the mechanisms underlying cross-contamination.
Assuntos
Arsênio , Compostagem , Animais , Suínos , Antibacterianos/farmacologia , Genes Bacterianos , Resistência Microbiana a Medicamentos/genética , Biotransformação , EstercoRESUMO
The livestock sector is responsible for a significant amount of wastewater globally. The microalgal-bacterial consortium (MBC) treatment has gained increasing attention as it is able to eliminate pollutants to yield value-added microalgal products. This review offers a critical discussion of the source of pollutants from livestock wastewater and the environmental impact of these pollutants. It also discusses the interactions between microalgae and bacteria in treatment systems and natural habitats in detail. The effects on MBC on the removal of various pollutants (conventional and emerging) are highlighted, focusing specifically on analysis of the removal mechanisms. Notably, the various influencing factors are classified into internal, external, and operating factors, and the mutual feedback relationships between them and the target (removal efficiency and biomass) have been thoroughly analysed. Finally, a wastewater recycling treatment model based on MBC is proposed for the construction of a green livestock farm, and the application value of various microalgal products has been analysed. The overall aim was to indicate that the use of MBC can provide cost-effective and eco-friendly approaches for the treatment of livestock wastewater, thereby advancing the path toward a promising microalgal-bacterial-based technology.
Assuntos
Bactérias , Gado , Microalgas , Eliminação de Resíduos Líquidos , Águas Residuárias , Águas Residuárias/química , Microalgas/metabolismo , Eliminação de Resíduos Líquidos/métodos , Animais , Bactérias/metabolismo , Poluentes Químicos da Água/metabolismo , Consórcios Microbianos/fisiologia , Biodegradação AmbientalRESUMO
The combination of microalgal culture and wastewater treatment is an emerging topic. This study investigated the use of different microalgae to treat different types of dairy farm wastewater. The results showed that the removal of ammonia nitrogen and total phosphorus by mixed microalgae was over 99% and 80%, respectively. The highest production of protein in biomass and extracellular polymeric substances was observed in high-concentration wastewater. In the phycosphere, the abundance of Proteobacteria and Cyanobacteria increased, while that of Bacteroidota decreased. Phycosphere bacteria were strongly correlated with microalgal growth and the composition of extracellular polymeric substances, especially with bound extracellular polymeric substances relative to soluble extracellular polymeric substances. Genes associated with photosynthesis and respiration in phycosphere bacteria were upregulated, contributing to the material exchange capacity in the microalgal-bacterial systems. The interaction between microalgae and phycosphere bacteria thus represents the core of the binary cultivation system-based wastewater treatment and requires further investigation.
Assuntos
Bactérias , Indústria de Laticínios , Microalgas , Águas Residuárias , Purificação da Água , Microalgas/metabolismo , Microalgas/crescimento & desenvolvimento , Águas Residuárias/microbiologia , Bactérias/metabolismo , Bactérias/genética , Purificação da Água/métodos , Fósforo/metabolismo , Fazendas , Nitrogênio/metabolismo , BiomassaRESUMO
A comprehensive, large-scale coastal investigation of antibiotics in seawater from Bohai Bay is lacking. Therefore, in this study, we investigated the occurrence and ecological risks of 45 antibiotics belonging to 5 classes in seawater from Bohai Bay, as well as their inter-relation with trace elements and other contaminants. The results show that tetracyclines (TCs) were detected in the highest concentration among the five classes (in the range of 0.6−2.0 µg/L). The total concentrations of the five classes of antibiotics were detected in the following order: tetracyclines (TCs) > quinolones (QAs) > sulfonamides (SAs) > macrolides (MAs) > lactams (LAs). Higher antibiotic concentrations were detected at the sampling sites closest to the coast or the shipping port. Among seven trace elements, four were quantitatively detected, with Zn representing the highest concentration. Antibiotic residuals were found to be positively correlated with total organic carbon (TOC), conductivity (Ec) and suspended solids (SS); pH and NH4+-N usually showed a negative correlation with antibiotics; TN and TP also exhibited relationships with antibiotics. The risk quotient (RQ) was calculated for different antibiotics at different sites. It was found that antibiotics pose higher risks to algae than to invertebrates or fish; sulfamethoxazole, enrofloxacin and ofloxacin were all found to pose high risk to algae at some of the sampling sites. Structural equation model (SEM) results show that trace elements, antibiotic levels and EC50 are the main factors affecting the ecological risks of antibiotics.
Assuntos
Oligoelementos , Poluentes Químicos da Água , Animais , Antibacterianos/análise , Baías , Água do Mar/química , Tetraciclinas , China , Monitoramento Ambiental , Poluentes Químicos da Água/análise , Medição de RiscoRESUMO
With the aim of controlling the pollution of antibiotic resistance genes (ARGs) in livestock and poultry wastewater, this paper highlights an ecological treatment technology based on plant absorption and comprehensively discusses the removal effect, driving factors, removal mechanism, and distribution characteristics of ARGs in plant tissues. The review shows that ecological treatment technology based on plant absorption has gradually become an important method of wastewater treatment of livestock and poultry breeding and has a good ARG removal effect. In plant treatment ecosystems, microbial community structure is the main driver of ARGs, while mobile genetic elements, other pollutants, and environmental factors also affect the growth and decline of ARGs. The role of plant uptake and adsorption of matrix particles, which provide attachment sites for microorganisms and contaminants, cannot be ignored. The distribution characteristics of ARGs in different plant tissues were clarified and their transfer mechanism was determined. In conclusion, the main driving factors affecting ARGs in the ecological treatment technology of plant absorption should be grasped, and the removal mechanism of ARGs by root adsorption, rhizosphere microorganisms, and root exudates should be deeply explored, which will be the focus of future research.
Assuntos
Microbiota , Águas Residuárias , Animais , Genes Bacterianos , Antibacterianos/farmacologia , Aves Domésticas , Resistência Microbiana a Medicamentos/genética , GadoRESUMO
The clusters formed by modified materials on its surface makes the application of functionalized biochars in adsorption face a great challenge. Here, a facile ball milling technology was innovatively proposed to tailor Fe-Al oxides-laden bagasse biochar to fabricate a novel adsorbent (BMFA-BC). Benefited from the increased exposure of Fe-Al oxides and, more importantly, enhanced functional groups by ball milling, the adsorption capacity of BMFA-BC for aqueous tetracycline reached up to 116.6 mg g-1 at 298 K. And the adsorption performance was temperature-dependent. Characterization analysis, batch sorption (thermodynamics, kinetics, isotherms, chemical factors) as well as data modeling illustrated that this superior adsorption ability could be attributed to π-π conjugation, H-bonding, complexation as well as pore filling. BMFA-BC displayed good adsorption capacity in multiple aqueous environments. The excellent regeneration ability, magnetic susceptibility ensured its viability for sustainable pollutants removal. These superiorities revealed that BMFA-BC was a suitable sorbent for antibiotics elimination.
Assuntos
Compostos Heterocíclicos , Poluentes Químicos da Água , Óxidos , Água , Adsorção , Antibacterianos/análise , Tetraciclina , Carvão Vegetal/química , Poluentes Químicos da Água/análise , CinéticaRESUMO
First time, this study synthesized a magnetic-modified sludge biochar (MSBC) as an activator of peroxymonosulfate (PMS) to eliminate sulfamethoxazole (SMX). The removal efficiency of SMX reached 96.1% at t = 60 min by PMS/MSBC system. The larger surface area and magnetic Fe3O4 of MSBC surface enhanced its activation performance for PMS. The PMS decomposition, premixing and reactive oxygen species (ROS) identification experiments combined with Raman spectra analysis demonstrated that the degradation process was dominated by surface-bound radicals. The transformed products (TPs) of SMX and the main degradation pathways were identified and proposed. The ecotoxicity of all TPs was lower than that of SMX. The magnetic performance was beneficial for its reuse and the removal efficiency of SMX was 83.3% even after five reuse cycles. Solution pH, HCO3- and CO32- were the critical environmental factors affecting the degradation process. MSBC exhibited environmental safety for its low heavy metal leaching. PMS/MSBC system also performed excellent removal performance for SMX in real waters including drinking water (88.1%), lake water (84.3%), Yangtze River water (83.0%) and sewage effluent (70.2%). This study developed an efficient PMS activator for SMX degradation in various waters and provided a workable way to reuse and recycle municipal sludge.
Assuntos
Sulfametoxazol , Poluentes Químicos da Água , Sulfametoxazol/química , Esgotos , Poluentes Químicos da Água/análise , Peróxidos/química , Água , Fenômenos MagnéticosRESUMO
Scientific interest in pollution from veterinary antibiotics (VAs) on intensive animal farms has been increasing in recent years. However, limited information is available on the seasonal pollution characteristics and the associated ecological risks of VAs, especially about the different scale farms. Therefore, this study investigated the seasonal pollution status and ecological risks of 42 typical VAs (5 classes) on three different scale pig farms (breeding scales of about 30,000, 1200, and 300 heads, respectively) in Tianjin, China. The results showed that large-scale pig farms usually had the highest antibiotic pollution levels, followed by small-scale pig farms and medium-scale pig farms. Among different seasons, antibiotic contamination was more severe in winter and spring than that in the other seasons. Tetracyclines (TCs) usually had higher proportions (over 51.46%) and the residual concentration detected in manure, and wastewater samples ranged from not detected (ND)-1132.64 mg/kg and ND-1692.50 µg/L, respectively, which all occurred for oxytetracycline (OTC) during winter. For the antibiotic ecological risks in the effluent, we found high-risk level of 12 selected VAs accounted for 58% in spring, and 7 kinds of VAs were selected in the amended soil, but nearly all the antibiotics had no obvious ecological risks except OTC (spring and summer). All these data provided an insight into the seasonal variability and the associated ecological risks of antibiotics on intensive pig farms, which can provide scientific guidance on decreasing antibiotic contamination to enhance environmental security in similar areas.
Assuntos
Antibacterianos , Esterco , Animais , Antibacterianos/análise , China , Monitoramento Ambiental/métodos , Fazendas , Esterco/análise , Estações do Ano , Suínos , Águas ResiduáriasRESUMO
Although the studies on antibiotic contamination are common at present, large-scale sampling studies drawing highly representative conclusions are still scarce. This study conducted a comprehensive investigation on a total of 1183 samples from 70 livestock farms within a sensitive area around reservoir waters. 45 types of antibiotics belonging to 5 different classes were monitored. This is the first analysis to comprehensively investigate the density distribution, source apportionment, ecological and health risk of antibiotics in an entire area of sensitive waters. The results showed that the layer manure samples had highest detection rate of antibiotics (0.0 %-96.1 %, average value = 30.7 %) followed by pig manure samples. Oxytetracycline had the highest concentration of 712.16 mg/kg in a pig manure sample. Different from using antibiotic concentration as a proxy for pollution level, the spatial density was calculated by averaging antibiotic concentration to area and converting different livestock to pig equivalent. The spatial density of pig equivalent can more realistically reflect the pollution caused by different breeds of livestocks. It was shown that the pig farms contributed higher to total antibiotic density than the layer and cattle farms did. After assessed, a few antibiotics (oxytetracycline, chlorotetracycline and tetracycline) have posed high ecological risks to soil around the farms. However, none of them caused hazard quotient (HQ) risk and carcinogenic risk (CR) to human health in the water of reservoir. Children were more likely to be at hazard risk than adults. Antibiotic mass fluctuation rules were analyzed along the chain (feed â livestock waste â soil â surface water). Feed, livestock waste and soil had similar diversity, but the antibiotic concentrations continued to decline, implying the possible sources of antibiotic residues were similar. Thus, it is important to reduce unnecessary antibiotic use to prevent the potential long-term risk of antibiotics.
Assuntos
Clortetraciclina , Oxitetraciclina , Animais , Antibacterianos/análise , Bovinos , Criança , China , Clortetraciclina/análise , Monitoramento Ambiental/métodos , Fazendas , Humanos , Gado , Esterco/análise , Oxitetraciclina/análise , Medição de Risco , Solo/química , Suínos , Água/análiseRESUMO
Contamination of antibiotic resistance genes (ARGs) from animals is a serious issue as they may spread to human pathogenic bacteria. The reduction of ARG contamination from livestock waste is thus essential. High solid anaerobic digestion (HSAD) is a new and effective technology although some aspects, such as change characteristics of ARGs at different reaction stages, have not been fully investigated. This study focused firstly on the variations in ARGs at different reaction stages in HSAD systems with five different starting methods: 1 natural start (the control) and 4 rapid starts by changing leachate reflux forms. The results showed that the rapid starting methods could accelerate start-up and increase biogas production by 312.5%. The starting and acidification stages showed higher microbial richness and diversity compared with the other stages. ARGs found to be reduced at acidification stage. Variation in ARGs at the starting and acidification stages was mainly driven by a combination of microbial community, mobile genetic elements (MGEs), and environmental factors; while the main contributory factors at the gas production stage were biomass and several unexplained factors. At the ending stage, the main driving factors were biomass and microbial communities. Most of the potential hosts (16/20) of the ARGs belonged to the Firmicutes phylum, which showed the lowest connections with the ARGs at the gas production stage.
Assuntos
Antibacterianos , Esterco , Anaerobiose , Animais , Antibacterianos/farmacologia , Biocombustíveis , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos , Humanos , Esterco/microbiologia , SuínosRESUMO
A field experiment with 24 different treatments was carried out to study the effects of a combination of water management (WM), soil application of calcium magnesium phosphate (CMP), and foliar spraying of Si/Se on Cd uptake by paddy rice (Teyou 524). The water management modes included W1 (conventional water management) and W2 (flooding during the whole growth period). The application of CMP included P1 (1800 kg·hm-2) and P2 (3000 kg·hm-2). The leaf spraying regulations included LS (2.0 mmol·L-1 Na2SiO3), LX (25 µmol·L-1 Na2SeO3), and LSX (1.0 mmol·L-1 Na2SiO3 and 12.5 µmol·L-1 Na2SeO3). The results indicated that, compared to the control (W1), flooding and CMP reduced soil exchangeable Cd by 10.3, 21.5, 32.2, 27.6 and 36.9% under conditions of W2, P1, P2, W2P1 and W2P2, respectively; but the grain yield was reduced under W2 condition. Some individual treatments, including W2, P1, P2, LS, LX, and LSX, could reduce Cd concentration in the grain by 23.1-60.3%; but the combined regulations could reduce grain Cd concentrations up to 79.5%. Only the combined mode of CMP and leaf spraying of Si/Se could control grain Cd concentration below the Chinese National Food Safety Standard (0.2 mg·kg-1). Combined modes of fertilizer application (W2 and CMP) and foliar spraying (Si/Se), including W2P2LS, W2P2LX, W2P2LSX, were the most effective in reducing the Cd transport coefficients of both root-to-straw (RS) and straw-to-seed (SS). Considering Cd concentration in grain, treatments W2P2LS and W2P2LSX were the most effective ones, which could reduce Cd concentrations to 0.090 mg·kg-1 and 0.089 mg·kg-1 in grain, respectively. These results demonstrated that combined manipulation of the root zone (W2 and CMP) and foliar spraying (Si/Se) can effectively reduce grain Cd concentrations in rice.
Assuntos
Oryza , Poluentes do Solo , Cádmio/análise , Fosfatos , Solo , Poluentes do Solo/análise , Água , Abastecimento de ÁguaRESUMO
As an emerging technology, high solid anaerobic digestion (HSAD) was usually hampered by the long lag phase of methane production. A reasonable starting mode enabled fast startup in HSAD, which was scarcely reported. This study established 5 starting modes for HSAD with pig manure. The results showed that system T4 (biogas slurry once and then autologous leachate reflux) had the shortest lag phase. Starting modes had a total effect of 36.6% on gas production, among which 17.1% affected gas production directly and 19.5% affected it through other factors. About 12/17 of antibiotic resistance genes (ARGs) and 3 mobile genetic elements (MGEs) were effectively reduced during HSAD. System T4 had the highest microbial diversity and the largest number of unique OTUs. MGEs explained most for ARGs variation (>50%), followed by microbial community. Most of the potential host genera for ARGs belonged to Firmicutes phyla, which could be decreased by starting modes.
Assuntos
Antibacterianos , Esterco , Anaerobiose , Animais , Antibacterianos/farmacologia , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos/genética , SuínosRESUMO
Antibiotic pollution from family animal farms is often neglected, but the waste from these farms usually caused more harm to the surroundings because arbitrary discharge without effective disposal. The pollution status and ecological risks of 45 veterinary antibiotics on 33 family animal farms in Dali city, Erhai Lake basin of China, were firstly delivered. The results showed that antibiotic contamination was prevalent in different environmental mediums (feed, manure, wastewater and soil) on these family farms. Manure had highest antibiotic levels among all the environmental mediums. Tetracyclines (TCs) usually had higher concentrations (ND-404.95 mg/kg) than the other classes, among which chlorotetracycline (CTC) was the dominant type. Among different animal species, target 13 pig farms had the highest antibiotic concentrations, the most total types and unique types of antibiotics, which were followed by target 11 chicken farms then target 9 cattle farms. The antibiotic densities of animal waste were calculated by per animal, which showed that pig waste presented high density; and family chicken farms were characterized by quinolone antibiotics (QAs) and macrolide antibiotics (MAs) pollution. For the antibiotic ecological risks in effluent water, oxytetracycline (OTC), CTC, ofloxacin (OFL), enrofloxacin (ENR), ciprofloxacin (CIP) and sulfamethoxazole (SMX2) exhibited much more toxic effects on algae. OTC and doxycycline (DXC) posed high risk for invertebrate; while no antibiotic caused high ecological risk for fish. Some antibiotics were quantitatively detected in the soil but no antibiotic posed obvious ecological risks on soils. However, the interaction of synergistic or antagonistic effects between different antibiotics should be brought to the forefront. This study gave some information of antibiotic pollution on family livestock farms, which indicated that animal waste from family farms was indeed an important pollution source of antibiotics for the environment.
Assuntos
Gado , Poluentes Químicos da Água , Animais , Antibacterianos/análise , Bovinos , China , Monitoramento Ambiental , Fazendas , Lagos , Suínos , Poluentes Químicos da Água/análiseRESUMO
A multiresidue method for identification and quantification of 45 veterinary antibiotics (VAs) belonging to 5 different drug classes has been developed, which is the first comprehensive method for pig manure. The proposed method used mixed liquor with methanol: acetonitrile: citrate buffer ratio of 1:1:2 to extract the target VAs from freeze-dried manure. The extracting solution passed through solid-phase extraction (SPE) procedure with Oasis HLB cartridges, which could isolate the target VAs and clean the samples in a single step. After blow-drying and concentrating, the samples were analyzed by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) in one single injection with a run time of 12 min. The average recovery rates for most of the VAs were in the range of 50-120% with relative standard deviations below 15%. Linearity was studied in the range between 2 and 1000 µg/kg using matrix-matched calibration and pure solvent calibration, to evaluate the matrix effects (MEs). The limits of detection (LDs) and quantification (LQs) were in the range of 0.01-1.54 µg/kg and 0.03-5.13 µg/kg respectively, except for penicillin G. Finally, the proposed method was used to quantify VA residues in real swine manure from three farms with different scales; tetracyclines, sulfonamides, quinolones and macrolides were the most frequently detected compounds.
Assuntos
Antibacterianos/análise , Cromatografia Líquida de Alta Pressão/métodos , Esterco/análise , Espectrometria de Massas em Tandem/métodos , Drogas Veterinárias/análise , Animais , Antibacterianos/isolamento & purificação , Limite de Detecção , Modelos Lineares , Reprodutibilidade dos Testes , Extração em Fase Sólida , Suínos , Drogas Veterinárias/isolamento & purificaçãoRESUMO
This study investigates how arsenic (As) uptake, accumulation, and migration responds to selenium (Se) foliar application (0-5.0 mg × kg-1). Rice varieties known to accumulate low (DOURADOAGULHA) and high (SINALOAA68) concentrations of arsenic were chosen to grow on soil with different As concentrations (20.1, 65.2, 83.9 mg × kg-1). The results showed that Se of 1.0 mg × L-1 significantly alleviated As stress on upland rice grown on the As-contaminated soil. Under light (65.2 mg × kg-1) and moderate (83.9 mg × kg-1) As concentration treatments, the biomass of upland rice was increased by 23.15% and 36.46% for DOURADOAGULHA, and 46.3% and 54.9% for SINALOAA68. However, the high Se dose (5.0 mg × kg-1) had no significant effect on biomass and heights of upland rice compared to plants where no Se was added. Se significantly decreased As contents in stems and leaves and had different effects on As transfer coefficients for the two rice varieties: when grown on soil with low and moderate As concentrations, Se could reduce the transfer coefficient from stems to leaves, but when grown on the high As soils, this was not the case. The chlorophyll content in plants grown in soil with the moderate concentration of As could be improved by 27.4%-55.3% compared with no Se treatment. Under different As stress, the Se foliar application increased the net photosynthesis, stomatal conductance, and transpiration rate, which meant that Se could enhance the photosynthesis of rice. The intercellular CO2 concentration variation implied that the stomatal or non-stomatal limitations could both occur for different rice varieties under different Se application doses. In conclusion, under moderate As stress, foliar application of Se (1.0 mg × L-1) is recommend to overcome plant damage and As accumulation.
Assuntos
Arsênio , Oryza , Selênio , Poluentes do Solo , Arsênio/farmacocinética , Cádmio , Fotossíntese , Ácido Selenioso , Selênio/farmacologia , Poluentes do Solo/farmacocinéticaRESUMO
To comprehensively understand how antibiotics affect anaerobic digestion, their stimulating effects on methane production cannot be ignored; however, few studies have evaluated these effects. This study investigated the stimulating effects of three typical antibiotics (oxytetracycline, sulfadimethoxine, and norfloxacin) on high solid anaerobic digestion. The results showed that 100â¯mg/L antibiotics exhibited a strong stimulating effect on CH4 yield; while other external carbon sources had no obvious effects. The stimulating effect was more obvious under low inoculation ratios, which could improve the system processing capacity of feed sludge. Lower lag phases were given by the modified Gompertz model when stimulating effects occurred. The variations of physicochemical parameters and microbial Venn maps both showed that day 5 was a critical point for digestion time. The relative abundance of Methanosarcina was enhanced when the stimulating effect occurred, whereas Methanoculleus decreased. Different microbial characteristics were obtained for different samples from the heat maps.