Analysis Of Harmful Components And Harmless Processing Of Livestock And Poultry Manures From Feedlots

In the last decades, intensive feeding industry has made rapid progress in China, and the contents of different deleterious contaminants, which are heavy metals, residues of animal medicine, salinities, and maleficent bacteria, in the manures of livestock and poultry have increased, so the healthy function of fertile soil have been restricted, even leading to the risk of eco-environment. The main chemistry ingredients of livestock and poultry manures of typical intensive feeding in Chinese seven provinces (or municipalities) were measured. Results showed that there were rich organic materials and inorganic minerals elements, such as nitrogen, phosphorus, potash, calcium, magnesium, iron, sodium, manganese, cobalt, and so on. As for the pig-manures, the measure results gained from 32 samples were that the average content of raw organic materials was 538.7g/kg, and the average content of the total nitrogen, total phosphorus, total potash were 18.6g/kg, 20.4g/kg, 14.0g/kg, respectively. As for the chicken-manures, the measure results from 23 samples were that the average content of raw organic materials was 438.9g/kg, and the average content of the total nitrogen, total phosphorus, total potash were 21.4g/kg, 11.6g/kg, 20.7g/kg, respectively. Additionally, the measure results of secondary and micronutrients in the manures of livestock and poultry were that the average contents of Ca Fe Mg Na Mn Co were 33.97g/kg 8.64g/kg 9.94g/kg 4.43g/kg 395.62mg/kg, 0.93mg/kg severally in the pig-manures, and were 54.36g/kg 7.70g/kg 8.26g/kg 7.20g/kg 396.27mg/kg 3.92mg/kg severally in the chicken-manures. Besides, the contents of some heavy metals (arsenic, copper, zinc, chromium) and salinities were high in livestock and poultry manures, and the variable range of Cu contents were 10.7-1591mg/kg in the pig-manures, and were 18.6-775mg/kg in the chicken-manures. The variable range of Zn contents were 71.3-8710mg/kg in the pig-manures, and were 83.9-699mg/kg in the chicken-manures. The variable range of Cr contents were 0-688mg/kg in the pig-manures, and were 1.56-298.6mg/kg in the chicken-manures. The variable range of As contents were 0.30-65.4mg/kg in the pig-manures, and were 0.01-19.6mg/kg in the chicken-manures. Moreover, the result of conductance, soluble nutrients elements, as well as contents of NaCl were 9.2ms/cm,1.9%,1.0% in the pig-manures, and were 12.2ms/cm, 2.7%, 1.6% in the chicken-manures. Furthermore, the antibiotics residues of tetracycline were detected in the manures. As for the pig-manures, the average contents of terramycin, tetracycline, and aureomycin were 9.09mg/kg, 5.22mg/kg, 3.57mg/kg detailedly, and the variational range of each antibiotics were 1.05-134.75 mg/kg, 0-78.57mg/kg, 0-78.57mg/kg separately. As for the chicken-manures, the average contents of the above three kinds of antibiotics were 5.97mg/kg, 2.63mg/kg, 1.39mg/kg orderly, and the variational range of each antibiotics were 2.85-23.43 mg/kg, 0-14.56mg/kg, 0-19.03mg/kg in sequence. To sum up, the manures of intensive feeding industry had potential risk on farmland, as a result, the livestock and poultry manures must be processed to harmlessness before their utilization. It is very important to establish a kind of determining method for residual antibiotics in livestock and poultry manures along with veterinary medicines polluting environment increasingly. This paper introduces simultaneous determination of 3 kinds of tetracycline residues in livestock and poultry manures by high performance liquid chromatography and the precision determining conditions, the method is with highly accurate. Spherigel C 18(5μm,250 the 4.6 mmids) is used with LC mobile phase of oxalic acid :acetonitrile: methanol=40:30:30( pH=3.0) during determining, the flow rate, UV examination wave-length and degree are 1.0 mls/min, 355 nm and 0.005 AUFSs, respectively. The sample is extracted with the Mcl-Vaine-Na2EDTA liquid by the centrifuge, then measuring the antibiotic density in livestock and poultry manures at the same time. The experimental recovery rate and the relative standard deviation are also effective. That method increases the sensitive degree and detection limit of TCs under the UV wave-length of 355nm because the condition of simultaneous determination is optimized. To research the toxicity of heavy metals (As, Cr, Cu, Zn), antibiotics (TTC, OTC, CTC) and NaCl on plants, the physiological items of Chinese cabbage were studied through pot cultivation, and sand, fluvo_aquic soil and red soil were selected as culture medium, and the physiological items were germination potential, germination percentage of seeds, and shoot length, taproot length, number of side root, fresh weight, content of chlorophyll and proline of young seedling , and so on. The major results are as follows: 1) As for the culture medium of sand, besides the praline content of Chinese cabbage, above physiological items decreased with the increase of heavy metals (As, Cr, Cu, Zn), antibiotics (TTC, OTC, CTC) and NaCl concentration, respectively, and the growth of Chinese cabbage were restrained significantly when the concentration of toxic additives were up to limited level. 2) As for the culture medium of fluvo_aquic soil and red soil, the physiological items of Chinese cabbage were promoted at the low concentration of heavy metals, antibiotics and NaCl, while the growth of Chinese cabbage were restrained at the high concentration of the toxic additives. 3) As for the same concentration of heavy metals, antibiotics and NaCl, the germination potential, germination percentage of seeds, and shoot length, taproot length, number of side root, fresh weight, content of chlorophyll, the ratios of a/b of little Chinese cabbage planted in fluvo_aquic soil and red soil were higher than that planted in sand, the reason may be that the toxicity stress were catabatic because of the organic matters, redox, and other physical - chemic characteristics of soils. 4) The content of praline in little Chinese cabbage increased with the increased concentration of heavy metals, antibiotics, NaCl, and the color of cabbage leaves changed green to yellow with the increased concentration of antibiotics especially, it showed that the antibiotics induced the etiolation of young cabbage. As compost is a new alternative bioremediation technology for treatment of organic pollutants and heavy metals, two experiments were conducted to evaluate effect of using thermophilic composting to break down the content of TCs(TTC OTC CTC) and H₂O extractible of heavy metals(Cu Zn Cr As). The result of TCs degradation test indicated that degradation of pig+straw(P+S) and chicken+straw(C+S) in all treatments to TTC,OTC and CTC were effective, but by comparision, the addition treatment of BM microorganism reagent to TCs degradation was more effective, its biodegradation rate was higher than that of P+S+TCs and C+S+TCs treatment. The biodegradation rate of OTC was the lowest in all treatments, and the rate of C+S+OTC treatment was 40.23%. The sort order of the three TCs biodegradation rate was TTC> CTC> OTC. The airslaked coal has the passivation effect to the heavy metal elements inside excrements of livestock and poultry, the result of heavy metal passivation test showed the effect of addition treatment of airslaked coal to H₂O extractible content of heavy metals, such as Cu, Zn, Cr and As, were obvious, the passivation effect of arislaked coal added treatment was better than that of no addition treatment. The H₂O extractible content of heavy metals to Cu, Zn, Cr and As, after and before composting of pig manure, reduced 6.17%, 6.40%, 4.17% and 1.83%, respectively, meanwhile, the H₂O extractible contents after and before composting of chicken manure reduced 7.07%, 5.69%, 5.50% and 2.07%, respectively.