[Degradation Characteristics of Antibiotics During Composting of Four Types of Feces].

The widespread use of antibiotics in feed results in a large number of antibiotic residues in feces. Composting technology can degrade these residual antibiotics. A pilot-scale aerobic composting device was used to analyze the antibiotic residues and composting degradation characteristics of four types of feces (maggot manure, chicken manure, pig manure, and cow manure). Results showed that sulfonamides (SAs), fluoroquinolones (FQs), tetracycline (TCs), and macrolides (MAs) were the main antibiotics, and different type of feces had different dominant antibiotics. The contents of FQs and oxytetracycline (OTC) were none on the seventh day of the compost, and their degradation rates were the fastest. After composting, the degradation rate of doxycycline (DOX) in the four types of fecal composts was more than 85%. Meanwhile, the degradation rates of SAs in chicken, pig, and cow manure composts were also more than 80%, which was much lower in the one in maggot manure compost. MAs were only found in maggot manure, and the degradation rate was 70.79% after composting. Correlation analysis indicated that the water content and bulk density were the most important environmental factors affecting the degradation rates of antibiotics in the four types of fecal composts.

Housefly maggot-treated composting as sustainable option for pig manure management.

In traditional composting, large amounts of bulking agents must be added to reduce the moisture of pig manure, which increases the cost of composting and dilutes the N, P and K content in organic fertilizers. In this study, maggot treatment was used in composting instead of bulking agents. In experiment of selecting an optimal inoculum level for composting, the treatment of 0.5% maggot inoculum resulted in the maximum yield of late instar maggots, 11.6% (maggots weight/manure weight). The manure residue became noticeably granular by day 6 and its moisture content was below 60%, which was suitable for further composting without bulking agents. Moreover, in composting experiment with a natural compost without maggot inoculum and maggot-treated compost at 0.5% inoculum level, there were no significant differences in nutrient content between the two organic fertilizers from the two treatments (paired Student's t15=1.0032, P=0.3317). Therefore, maggot culturing did not affect the characteristics of the organic fertilizer. The content of TNPK (total nitrogen+total phosphorus+total potassium) in organic fertilizer from maggot treatment was 10.72% (dry weight), which was far more than that of organic fertilizer made by conventional composting with bulking agents (about 8.0%). Dried maggots as feed meet the national standard (GB/T19164-2003) for commercial fish meal in China, which contained 55.32 ± 1.09% protein; 1.34 ± 0.02% methionine; 4.15 ± 0.10% lysine. This study highlights housefly maggot-treated composting can be considered sustainable alternatives for pig manure management to achieve high-quality organic fertilizer and maggots as feed without bulking agents.

Rapid production of maggots as feed supplement and organic fertilizer by the two-stage composting of pig manure.

A two-stage composting experiment was performed to utilize pig manure for producing maggots as feed supplement and organic fertilizer. Seven-day composting of 1.8 ton fresh manure inoculated with 9 kg mixture of housefly neonates and wheat bran produced 193 kg aging maggots, followed by 12 week composting to maturity. Reaching the thermophilic phase and final maturity faster was characteristic of the maggot-treated compost compared with the same-size natural compost. Upon the transit of the maggot-treated compost to the second stage, the composting temperature maintained around 55 °C for 9 days and the moisture decreased to ~40%. Moreover, higher pH, faster detoxification and different activity patterns for some microbial enzymes were observed. There was a strong material loss (35% water-soluble carbon and 16% total nitrogen) caused by the maggot culture in the first stage. Our results highlight a higher economic value of pig manure achieved through the two-stage composting without bulking agents.

1,3-Bis(4-tert-butyl-benz-yl)pyrimidine-2,4(1H,3H)-dione.

In the crystal structure of the title mol-ecule, C(26)H(32)N(2)O(2), the six methyl groups are disordered over two positions, with site-occupancy ratios of 0.665 (8):0.335 (8) and 0.639 (8):0.361 (8). The central pyrimidine ring is almost planar with an r.m.s. deviation of 0.009 Å. The dihedral angles formed by the two benzene rings with the pyrimidine ring are 70.70 (8) and 88.02 (9)°. The dihedral angle between two benzene rings is 46.67 (10)°.

[Effect of aeration intensity on the nitrogen and phosphorus removal performance of AOA membrane bioreactors].

The ability of simultaneous phosphorus and nitrogen removal of sequencing batch membrane bioreactor run in anaerobic/oxic/ anoxic mode (AOA MBR) was examined under three aeration intensities [2.5, 3.75 and 5.0 m3 x (m2 x h)(-10]. The results showed that the averaged removals of COD were over 90% at different aeration intensities. And the higher aeration intensity was, the more ammonia nitrogen removal rate achieved. The removal rates of NH4(+) under the three aeration intensities were 84.7%, 90.6% and 93.8%, respectively. Total nitrogen removal rate increased with the increasing aeration intensity. But excessive aeration intensity reduced TN removal. The removal rates of TN under the three aeration intensities were 83.4%, 87.4% and 80.6%, respectively. Aeration intensity affected the denitrifying phosphorus ability of the AOA MBR. The ratio of denitrification phosphorus removal under the three aeration intensities were 20%, 30.2% and 26.7%, respectively.

[Study on the degradation of AO7 by UV/K2S2O8, system: kinetics and pathways].

The UV photolysis of S2O8(2-) is a novel advanced oxidation technologies (AOTs), which leads to the formation of strong oxidizing radicals, sulfate radicals (SO4(*-)). The effect of oxidant K2S2O8 concentration, the initial pH of solution and various inorganic anions (H2PO4-, HCO3-, NO3- and Cl-) were investigated using AO7, a kind of azo dye, as a model pollutant. The degradation kinetics of AO7 followed pseudo first-order kinetics and reaction rates related to PMS concentrations. When the initial concentration of AO7 was 0.14 mmol/L, the optimal molar ratio of oxidant K2S2O8 to pollutants AO7 was 20. The effect of initial pH had great effect on the AO7 degradation rate during UV/K2S2O8 system. Increasing system pH results in the formation of *OH from SO4(*-). The effects of four inorganic anions (H2PO4-, HCO3-, NO3- and Cl-) all had some negative effect on the degradation of AO7. Based on the results of GC/MS, three main intermediates (2-naphthalenol, coumarin and 1,2-benzenedicarboxylic acid) were identified, thus the degradation pathway for SO4(*-) induced by UV/K2S2O8 was proposed accordingly.

rac-Ethyl 4-hy-droxy-6-(2-hy-droxy-phen-yl)-2-oxo-4-(trifluoro-methyl)per-hydro-pyrimidine-5-carboxyl-ate.

In the title compound, C(14)H(15)F(3)N(2)O(5), prepared by reaction of 2-hy-droxy-benzaldehyde, ethyl 4,4,4-trifluoro-3-oxobutano-ate and urea, the tetra-pyrimidine ring adopts a half-chair conformation. The crystal structure is stabilized by five inter-molecular hydrogen bonds, three O-H⋯O and two N-H⋯O, giving cyclic dimers (through three hydrogen bonds) which are further extended into a two-dimensional network.

rac-6-Hy-droxy-4-(4-nitro-phen-yl)-5-(2-thienyl-carbon-yl)-6-(trifluoro-meth-yl)-3,4,5,6-tetra-hydro-pyrimidin-2(1H)-one monohydrate.

The title compound, C(16)H(12)F(3)N(3)O(5)S·H(2)O, was prepared by reaction of 4-nitro-benzaldehyde, 4,4,4-trifluoro-1-(thio-phen-2-yl)butane-1,3-dione and urea. The asymmetric unit contains two independent mol-ecules, with essentially identical geom-etries and conformations. The dihydro-pyrimidine rings adopt a half-chair conformation. The dihedral angles between the benzene ring and the thio-phene ring are 54.82 (8) and 58.72 (8)° in the two mol-ecules. The mol-ecular conformation of one of the mol-ecules is stabilized by two intra-molecular O-H⋯O hydrogen bonds, generating an S(6) ring. The crystal structure is stabilized by inter-molecular O-H⋯O and N-H⋯O hydrogen bonds.