摘要
Swine farm wastewater is extremely harmful to the environment if not treated before it is discharged.In this study,a system was developed and optimized for testing the high levels of organic matter in swine farm wastewater utilizing a microalgae/bacteria co-culture combined with a novel closed-loop extraction and dilution process.Importantly,the system produces biomass that also could be harvested and used in value-added applications.The efficacy of biomass as a biofertilizer was demonstrated by using a model plant of Arabidopsis.In addition,the analysis of biomass indicates that it also has potential as a source for biofuel.After a 20-d cultivation period,a yield of biomass was achieved to 2.063 g/L of wastewater.The highest removal rates recorded in steady state conditions were:13.8 mg/L·d of Total Nitrogen(TN);11.5 mg/L·d of Ammonia Nitrogen(NH_(4)^(+)-N);24.8 mg/L·d of Chemical Oxygen Demand(COD);and 16.9 mg/L·d of Total Phosphorus(TP).After cultivation,the composition of the biomass was analyzed on a dry basis;the major components were protein(44.9%),lipids(24.6%),carbohydrates(19.9%),Chlorophyll-A(2.75%),Chlorophyll-B(1.66%),and carotenoids(0.57%).This biomass was diluted with water(5%by weight)and used as a biofertilizer to grow Arabidopsis.The results showed that the average root and stem lengths of Arabidopsis were 43.0%and 55.0%longer compared to those of the control group.Additionally,the number of leaves and the maximum leaf length increased by 30.2%and 39.7%;and the fresh and dry leaf weights increased by 44.0%and 33.7%,respectively.These results demonstrate the efficacy of this system for treating swine farm wastewater whilst simultaneously producing a value-added microalgae/bacteria biomass.This paper also demonstrated the use of biomass as a fertilizer for cultivating a value-added crop and,based on the compositional analyses,propose that the biomass could be used as a raw material for biofuel production due to its high lipid content of 24.6%.By constructing a microalgae/bacteria symbiosis sys
基金
supported by National Key R&D Program of China(Grant No.2022YFC3902403)
Beijing excellent talent training project(Grant No.2018000020144G074)
Special project on green campus of Beijing Union University(Grant No.zk50202101)
Research innovation grant for graduate students of Beijing Union University(Grant No.yz2020k001)
Scientific research project grants from Beijing Union University(Grant No.ZK130202103,JB202101,XP202004)
University of Minnesota Mn Drive Environment(MNE12)and Center for Biorefining.
