沼液基含腐植酸水溶性液体肥制取工艺参数优化

Parameter optimization of preparation for biogas slurry based water-soluble liquid fertilizer containing humic acid

为探索沼液开发含腐植酸水溶性液体肥的可行性和工艺方法,促进沼液无害化处理和资源化利用,该文以沼液为基料,以黄瓜配方肥为基肥,螯合剂、稳定剂为辅料,开展了不同工艺参数(沼液添加量、稳定剂添加量、螯合剂添加量,反应温度,反应时间)对含腐植酸水溶性液体肥质量指标影响的单因素和正交试验。结果表明:沼液、螯合剂、稳定剂添加量以及反应温度、时间对液体肥中水不溶物含量有重要影响,沼液制取黄瓜专用型含腐植酸水溶性液体肥的较优工艺参数为:基肥添加量为原料质量的39.6%,沼液添加量为59%,螯合剂添加量为4%,稳定剂添加量为0.4%,反应温度为40℃、反应时间为1.5 h的条件下,所获得的液体肥中总养分质量浓度为220.47 g/L,腐植酸质量浓度为33.25 g/L,水不溶物质量浓度为18.6 g/L,利用该工艺方法生产出来的沼液基含腐植酸水溶性液体肥料产品具有腐植酸、氮磷钾营养元素含量高、水不溶物含量低等特点。该研究为利用沼液开发高品质含腐植酸水溶性液体肥提供技术支撑。

Water-soluble liquid fertilizer containing humic acid is one of the important directions of liquid fertilizer development in the future. It not only has the high utilization efficiency and the abilities of water saving, environmental protection and increasing production, but also has the functions of enhancing plant resistance, promoting flower bud differentiation and development, and improving the quality of crops. According to the analysis, 90% of the nutrients of livestock and poultry manure and straw were preserved after biogas fermentation, and about 1/3 of nutrients entered biogas slurry. Using biogas liquid to develop liquid fertilizer could alleviate the problem of methane elimination and save water resources, besides producing high quality liquid fertilizer. In order to explore the feasible method for the development of water-soluble liquid fertilizer containing humic acid, in this paper, biogas slurry, formula fertilizer of cucumber, chelating agent, and stabilizer were used as the main raw materials, and the effects of different process parameters（amount of biogas slurry, amount of stabilizer, amount of chelating agent, reaction temperature and reaction time） on the performance of water-soluble liquid fertilizer containing humic acid were studied. The results showed that amount of biogas slurry, amount of chelating agent, amount of stabilizer, reaction temperature and reaction time had an important effect on the content of water insoluble substance in liquid fertilizer containing humic acid. In the case of the addition of certain amount of biogas solution, the impact importance of each factor was additive amount of stabilizer reaction temperature additive amount of chelating agent reaction time. Adjusting amount of chelating agent, amount of stabilizer, reaction temperature and reaction time could reduce the concentration of water insoluble matter to a certain extent, and improve the total nutrient concentration in the liquid fertilizer. The excellent process parameters for preparing water-soluble liquid fertilizer were formula fertilizer of cucumber accounting for 39.6% of mixed material, biogas slurry 59%, stabilizer 0.4%, chelating agent 4%, reaction temperature of 40 ℃, and reaction time of 1.5 h. Under such conditions, the content of total nutrient was 220.47 g/L, humic acid was 33.25 g/L and insoluble matter was 18.6 g/L. The full utilization of biogas slurry was an important guarantee for the sustainable operation of biogas projects. From another point of view, under the premise of meeting the basic quality standard of liquid fertilizer, it was also of great practical significance to achieve maximum utilization of biogas slurry. The method not only realizes the full utilization of biogas slurry, but also has the advantages of high content of humic acid and nitrogen. It provides technical support for developing high quality water-soluble liquid fertilizer containing humic acid using biogas slurry.