【作者】 徐国锐；

【导师】 石伟勇； 王伟国；

【作者基本信息】 浙江大学 ， 农业资源利用， 2012， 硕士

【摘要】 近年来,随着我国规模化养殖场数量的增加及集约化程度的不断提高,畜禽粪污导致的环境污染问题日益严重。据统计,至2007年全国畜禽粪污总排放量达30亿t以上,总COD排放量7700万t以上,是全国工业和生活污水COD排放总量的5倍多。对于畜禽粪污污染的控制,以厌氧发酵为主要技术单元的畜禽粪污沼气工程逐渐得到广泛应用及关注,至2010年底全国大中型沼气工程达66978.5万立方米。随着大型沼气工程的建设,必然伴随着大量沼液的出现。沼液虽然富含总氮、总磷、钾离子、有机质等物质,但是作为肥料沼液具有的养分含量低、使用量大、使用不便的特点,这些因素严重制约着沼液资源化利用。特别是规模化养殖场沼气工程每天所产生的大量沼液,无法及时消纳就会造成严重的环境问题。本文结合沼液特点进行纳滤膜浓缩实验。重点研究纳滤膜浓缩工艺,浓缩过程对浓缩液和透过液成分的影响,并使用浓缩液配置出氨基酸水溶性肥料。在实验的过程中,主要得出如下结论：1通过对宁波鄞州区各大规模化养殖场的50多个沼气池沼液进行调查分析,发现沼液中含有丰富的氮磷钾元素、有机质和活性物质；同时发现不同沼气发酵工艺和沼气工程的不同管理对沼液成分有较大影响。2确定了较优的沼液浓缩工艺为：沼液原液—多层格栅—石英砂过滤器—保安过滤器—纳滤膜浓缩；纳滤膜截留分子量为90,牛粪沼液浓缩倍数4倍,猪粪沼液浓缩倍数5-6倍最为合适。沼液浓缩液能够满足液体有机肥开发的需要。3采用截留液全部循环的操作模式,在操作压力、流量、温度等因素不变的条件下,膜通量会随着运行时间的延长而下降。随着浓缩倍数的增加,浓缩液和透过液的pH下降,电导率上升。同时发现纳滤膜对二价Ca、Mg、Fe和Zn离子具有较高的截留效果。4通过沼液浓缩液复配技术和配方筛选,研制出沼液氨基酸水溶性肥料产品,经检测产品符合NY1429-2010标准,并有良好的施用效果。5使用猪粪浓缩液配置无土栽培营养液,并进行无土栽培小白菜的实验,发现该营养液比对照组(霍格兰营养液处理)的产量和叶绿素含量高,证明使用沼液浓缩液配置无土栽培营养液具有可行性。更多还原

【Abstract】 In recent years, China’s large-scale farms and the intensification of the constant increase in the number, result in growing problems of environmental pollution brought by livestock dung. According to statistics, by the year 2007, the total emissions of the animal dung in the whole nation had reached up to 30 million tons or more, and the total COD emissions were more than 77 million tons which are five times more than the total COD emissions of nationwide industrial and domestic wastewater. As for the pollution control of animal dung, the main technology to anaerobic fermentation of animal dung biogas units are widely used and increasingly concerned about. To the end of 2010, large and medium-sized biogas projects have reached 669.785 million cubic meters. Biogas slurry will be heavily produced with the development of large biogas project.Although biogas slurry is rich in COD, BOD, SS, total nitrogen, ammonia nitrogen, total phosphorus and other substances, biogas slurry as fertilizer nutrient contains several characteristics:its content is low and is inconvenient to use except its widely using. Those characteristics severely restrict the utilization of biogas resources, especially the biogas project taken by those large-scale farms produced a large number of biogas per day which would bring about serious environmental problems without timely consumption.In this paper, the nanofiltration membrane enrichment experiments are carried out with biogas slurry characteristics. The paper will focus on the following aspects: nanofiltration membrane concentration process, the concentration of the concentrated liquid and liquid ingredients by the impact, the use of concentrated solution developed series of organic liquid fertilizer. A pot study and concentrate made with nutrient solution of soilless cultivation of cabbage yield and quality. 1, Investigation and analysis of the Ningbo Yinzhou District, various large-scale farms of more than 50 biogas digesters biogas slurry, biogas slurry containing NPK and other elements and organic matter and active substances, but also found that the methane fermentation process and biogasproject management of biogas slurry composition has a greater impact.2, Determined the best enrichment process:raw biogas, multilayer grille, quartz sand filter, the security filter, nano filtration membrane enrichment, cyele of concentration for biogas of cow dung is 4 times,5-6 times is the most appropriate for pig manure, as adopting Nanofiltration membrane with the cut-off molecular weight of 90. Biogas concentrated solution can meet the needs of the development of liquid organic fertilizer.3, As the operating pressure, flow rate, temperature and other factors keep constant,membrane flux will decline with the extension of time, adopting the intercept liquid all cycle operation mode. Along with the increase of concentration ratio, concentrate pH rose, permeate pH dropped, conductivity of both all increase. Also found that the nanofiltration membrane has a high retention effect of divalent Ca, Mg, Fe and Zn ions.4, Amino acid soluble fertilizer products, developed through concentrate enrichment process and blends with technology, meet the NY 1429-2010 standard, and there is a good application.5, The output and chlorophyll content of cabbage in the Soilless cultivation cabbage experiment, adopting the concentrate of pig manure as soilless culture solution, are higher than the control group, which adopted Hoagland nutrition solution.The result showed biogas concentrate can be used as nutrient solution in soilless culture.更多还原