| Using the cotton stalk mechanical pulping waste liquor fermented by bacillus subtilis SY-1to bioremediation in the vegetable cultivation ground, is a new method to resource utilization of papermaking wastewater. The study researched the optimum fermentation conditions for cotton stalk mechanical pulping waste liquor as medium to culture bacterial strain SY-1. The optimal condition of fermentation was as follows:initial pH7.4, culture temperature34℃, inoculum quantity8%, the amount of liquid50mL/250mL, the rotation speed150r/min, culture time16h.The effects of different concentrations of the bioconverted cotton stalk mechanical pulping waste liquor (after fermentation by bacillus subtilis SY-1) on the growth of vegetables were discussed by laboratory simulation test and field test. The results showed that the bioconverted liquid, with the suitable concentration,could enhance seed vigor. Eggplant seeds germination rate could be superior to the control group and increased by42.1%. The bioconverted liquid was suitable for accelerating germination,and different vegetable seeds could be adaptive to different concentrations of the bioconverted cotton stalk pulping waste liquor. To eggplant seeds, tomato seeds and Chinese cabbage seeds, the suitable dilution multiple was respectively10times,15times and25times. The bioconverted liquid could improve antiviral ability and growth of vegetable seedlings by promoting activity of defense enzymes. With the suitable concentration, activities of PAL, PPO, POD, SOD in eggplant seedlings respectively increased by30.3%,49.6%,130%,84.68%. The bioconverted liquid had a good effect on vegetable growth. When the bioconverted liquid was diluted15times, tomato plant height inceased by30.2cm within30days, and was higher by73.6%than the control group. At the same time, the bioconverted liquid could also improve the development quality and fruit quality of vegetables and prolong their preservation time. With the suitable concentration, lycopene and Vc content in tomato respectively increased by34.4%and11.3%, compared with the control group.Preliminary study on the effects of different concentrations of the bioconverted liquid on nitrate nitrogen content, salt content and microbial community in soil was discussed. The results showed that, after using the bioconverted liquid, the number of bacillus subtilis SY-1increased in soil. This could speed up decomposition of nitrate nitrogen, improve distribution of microbial community in soil, and the saline and alkaline of soil did not change obviously through using3times. When the bioconverted liquid was diluted15times, it had a better effect on improve distribution of microbial community. Compared with the control group, the amount of bacterium and actinomycetes respectively increased by55.2%,53.3%; the number of fungus decreased by54.6%. |
