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Wu Y.,South China Agricultural University | Wu Y.,Key Laboratory of Agroecology and Rural Environment of Guangdong Regular Higher Education Institutions | Huang L.,South China Agricultural University | Wang X.,South China Agricultural University | And 5 more authors.
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2011

Veterinary drug residue in the sewage is one of the most important factors which impacts the effect of anaerobic digestion. Effects of tylosin on anaerobic digestion of swine wastewater at two concentration levels were studied by two methods as adding swine manure collected from swine fed with tylosin in diets and adding tylosin into antibiotic free swine manure. Anaerobic digestion experiments were conducted at 20°C in laboratory digesters which the effective volume was 1300 mL. The results showed that the parent material of tylosin was not detected in the anaerobic digestion during the experimental period after seven consecutive days of adding tylosin at a rate of 7.42 μg/g and 12.96 μg/g respectively. Compared with the control, the presence of tylosin in swine manure enhanced methane production by 24.6% averagely. The trials adding tylosin at the concentration of 7.42 μg/g swine manure produced more methane than that of 12.96 μg/g. But there were no significantly difference between two methods. The NH 4 +-N concentration in trials adding swine manure collected from swine fed with tylosin in diets was significantly higher than that in the trials adding tylosin into antibiotic free swine manure. But there were no significantly difference between two adding concentrations of tylosin. Compared with the control, the trial with addition of tylosin had no significant effect on the pH, TN, COD of biogas slurry, and TN, organic matter of biogas sludge. Under the condition recommended by this article, it was observed that the presence of tylosin with the concentration of 7.42 μg/g and 12.96 μg/g swine manure had no negative effect on anaerobic digestion of swine sewage, and two methods suited for studying the effect of tylosin on anaerobic digestion. Source


Chen G.-X.,South China Agricultural University | He W.-W.,South China Agricultural University | Wang Y.,South China Agricultural University | Zou Y.-D.,Nanhai Entry Exit Inspection and Quarantine Bureau | And 3 more authors.
Science of the Total Environment | Year: 2014

The degradation behavior of veterinary antibiotics in soil is commonly studied using the following methods of adding antibiotics to the soil: (i) adding manure collected from animals fed with a diet containing antibiotics, (ii) adding antibiotic-free animal manure spiked with antibiotics and (iii) directly adding antibiotics. No research simultaneously comparing different antibiotic addition methods was found. Oxytetracycline (OTC) was used as a model antibiotic to compare the effect of the three commonly used antibiotic addition methods on OTC degradation behavior in soil. The three treatment methods have similar trends, though OTC degradation half-lives show the following significant differences (P. <. 0.05): manure from swine fed OTC (treatment A). <. antibiotic-free manure. +. OTC (treatment B). <. OTC (treatment C). Differences could be caused by distinct chemical reaction equilibria due to dissimilar concentrations of 4-epi-OTC and α-apo-OTC. The pH could also have affected the concentration of 4-epi-OTC and α-apo-OTC, thus influencing OTC degradation. The treatments presenting manure (A and B) significantly enhanced EC, enzyme activity, microbial biomass carbon and nitrogen when compared to the treatment without manure (C), thus increasing degradation of OTC in the soil. Because the main entry route for veterinary antibiotics into soil is via the manure of animals given with antibiotics, the most appropriate method to study the degradation and ecotoxicity of antibiotic residues in soil may be to use manure from animals that are given a particular antibiotic, rather than by adding it directly to the soil. © 2014 Elsevier B.V. Source


Wang X.,South China Agricultural University | Guo R.,South China Agricultural University | Ma B.,Nanhai Entry Exit Inspection and Quarantine Bureau | Liang J.,University Putra Malaysia | And 2 more authors.
Environmental Progress and Sustainable Energy | Year: 2014

This study examined the fate and effects of tylosin (TYL) on anaerobic digestion of swine wastewater at two concentrations of tylosin A (TYLA) using manure collected from swine fed with TYLA (TYLFED) or direct addition of TYLA (TYLADD) to antibiotic-free swine manure, to examine whether there are differences between the two TYL addition methods on methane production and other fermentation parameters. TYLA and tylosin D (TYLD) concentrations, pH, Chemical oxygen demand (COD), Total nitrogen (TN), and diversity of methanogenic archaea population were parameters used for this study. The results showed that concentrations of TYLA and TYLD in the TYL FED treatment were higher (P < 0.05) than those in the TYL ADD treatment. Methane production in the TYLFEDH and TYLFEDL was reduced by 35.52% and 37.06%, respectively, compared with the control during the 7 days addition period; but for TYLADDH and TYLADDL, the decrease (P < 0.05) was only 12.98% and 7.84%, respectively. The diversity index of methanogenic archaea in the TYL FED treatment were lower than that in the control and the TYL ADD on Day 4, but no difference (P > 0.05) between the control and the TYLADD treatment was observed. pH, COD, and TN were not affected by treatment. Our results showed clear differences in the rate of methane inhibition by the two antibiotic inclusion methods; been higher for the TYL FED treatment than the TYLADD treatment. Since the former method resembles more under actual farm conditions, we suggested that studies on effects of antibiotic residues on anaerobic fermentation should adopt such an approach. © 2013 American Institute of Chemical Engineers. Source


Huang L.,South China Agricultural University | Guo R.,South China Agricultural University | Liang J.,University Putra Malaysia | Ma B.,Nanhai Entry Exit Inspection and Quarantine Bureau | And 2 more authors.
Asian Journal of Chemistry | Year: 2014

Veterinary antibiotic residue in manure is one of the most important factors which have an impact on the anaerobic digestion. This article studied the effect of sulfamethazine (SM-2) on psychrophilic anaerobic digestion of swine manure by two adding methods, addition of manure from swine fed with SM-2 in diet and direct addition of SM-2 with blank manure, under two adding concentrations of SM-2 (2.38 and 1.24 mg/g dry swine manure). Anaerobic digestion experiment was conducted at 20 °C in laboratory digesters with the effective working volume of 1.3 L. Methane production of each digester was measured by displacement method daily. Grad samples were collected to determine the concentration of SM-2, pH, chemical oxygen demand (COD) in slurry and organic matter in biogas residue. The results showed that the concentration of SM-2 in anaerobic system fed with manure containing SM-2 was lower than that fed with blank manure and SM-2 under the same addition of SM-2 and the degradation rate of SM-2 in the high concentration treatment was faster than that in the low concentration treatment. Compared with the control group, the treatments added with SM-2 had no significant difference in methane production, COD in slurry and organic matter in biogas residue, but adding SM-2 and blank manure improved pH of swine slurry in SM-2 adding period. Due to the different degradation rate of SM-2 in anaerobic digestion between the two adding methods of SM-2, using manure collect from animals administered with SM-2 is more appropriate to assess the effect of SM-2 on anaerobic digestion. Source


Peng P.-C.,South China Agricultural University | Wang Y.,South China Agricultural University | Liu L.-Y.,South China Agricultural University | Zou Y.-D.,Nanhai Entry Exit Inspection and Quarantine Bureau | And 4 more authors.
Poultry Science | Year: 2016

The excretion rates and ecological risk to the environment of three commonly used veterinary antibiotics (VAs), amoxicillin, ciprofloxacin, and doxycycline, in layer hen manure during the application and withdrawal periods were investigated in a study consisting of a control group fed with VA-free basal diet and nine treatment groups consisted of three levels (200 mg/kg, 100 mg/kg, and 50 mg/kg) of amoxicillin (AMX), ciprofloxacin (CIP), or doxycycline (DOC). Each treatment group was replicated seven times with three layer hens per replication. Results of the study showed that the average excretion rates of AMX in the 200, 100, and 50 mg/kg groups were 67.88, 55.82, and 66.15%, respectively, while those for CIP and DOC were 47.84, 51.85, and 44.87% and 82.67, 94.39, and 95.72%, respectively. The concentrations of the above veterinary drugs in manure decreased sharply in the withdrawal period (7, 28, and 10 d, respectively), for AMX, DOC, and CIP. Neither AMX nor DOC was detected in the manure after the withdrawal period. In contrast to AMX and DOC, the excretion rate of CIP was significantly lower and thus had a longer residence time. Ecological risk study, estimated using hazard quotient values, showed that AMX in the 100 and 50 mg/kg groups posed no risk to the environment after d 1 of withdrawal, while CIP in the 50 mg/kg group posed no risk to the environment from d 5 of withdrawal. CIP in the 200 and 100 mg/kg groups required 10 d withdrawal in order to pose no risk to the environment. In contrast, DOC residue during withdrawal in the manure posed no risk to the environment, thus making it more environmentally safe. © 2016 Poultry Science Association Inc. Source

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