餐厨垃圾废水制备液态解磷菌剂研究

Preparation of liquid bacterial fertilizer of phosphate-solubilizing bacteria from food waste-recycling wastewater

本研究探讨了餐厨垃圾废水用作发酵基质生产液态解磷巨大芽孢杆菌菌肥的可行性.结果表明,餐厨垃圾废水培养的巨大芽孢杆菌经过3~4d的调整期即进入对数生长期,第6~7d活菌数达到最大,而经过湿热预处理得到的II类废水较I类废水更适宜用作巨大芽孢杆菌的培养基质,其菌液活菌数是I类废水培养的活菌数的5倍(4.8×10^(15)CFU/mL).废水中的盐分对巨大芽孢杆菌的生长代谢影响显著:活菌数随着NaCl含量的增加先升高后快速降低,最利于菌种培养的NaCl浓度为10g/L.p H值和温度极显著影响巨大芽孢杆菌的生长,而摇床转速和接种量对菌株培养影响不显著,正交试验确定的较优培养条件为pH=8、T=35℃、转速80r/min、接种量2%(V/V).餐厨垃圾废水制备的解磷菌肥可实现土壤中固化磷的有效磷化:施用0.025‰~2.5‰质量比例解磷菌剂的土壤生长的黄豆苗干重可达到按照5‰质量比例施加无机复合肥生长的黄豆苗的70.7%~84.5%,其中微生物菌肥的最佳施用量为0.25‰.

The feasibility of using food waste-recycling wastewater as fermentation substrate for producing liquidphosphate-solubilizing bacillus megaterium fertilizer was investigated. The results showed that bacillus megateriumcultured in the food waste-recycling wastewater reached logarithmic growth stage in as short as 3~4 days of adaptationperiod, and the number of strains reached the maxima on the 6~7th day. The wastewater II generated from hydrothermalpre-treatment was more suitable to be the fermentation substrate than wastewater I. The strain numbers cultured inwastewater II was 5times of what was cultured in wastewater I (4.8×1015CFU/mL). Salt concentration in the wastewaterhad great influence on the growth and metabolism of Bacillus megaterium: the strain numbers first increased and thensteeply decreased with the increase of NaCl concentration, indicating that the optimal NaCl concentration for bacterialculture was 10g/L. The variation of pH and temperature affected the growth of bacillus megaterium significantly, whileshaking speed and strain inoculation volume were not key influencing factors. The optimal culture conditions were pH 8,T=35℃, shaking speed 80r/min, and inoculums of 2%(V/V) as determined by orthogonal experiment. Phosphatesolubilizingfertilizer prepared by food waste-recycling wastewater was able to achieve effective phosphating ofimmobilized phosphorus: the dry weight of soy beans grown in soils amended with 0.025‰~2.5‰ of phosphatesolubilizingfertilizer was 70.7%~84.5% of that grown in the soil amended with 5% of inorganic fertilizer on weight basis.Moreover, the optimal amended ratio of the microbial fertilizer was 0.25‰.