Study On Agricultural Utilization Of CO₂Recovered From Simulative Industrial Waste Gas

At present, China has become the world's leader in annual CO₂emission. As theintensifying of greenhouse effect and the urgent needs of CO₂emission reduction from peoplearound the world, it becomes increasingly crucial for us to find proper way to reduce CO₂emission. Thus, facing the current development of China's circular economy, rationalexploitation and utilization of CO₂recovered from industrial waste gas,which is an excellentcarbon resource with huge potential value has become a major issue for us.In this study, firstly, a self designed CO₂fertilizer generator was built to purify andseparate CO₂from simulated industrial waste gas, then, agricultural utilization research wasconducted by utilization of the recovered CO₂. The second part of this research wasconcentrated on the effect of waste gas CO₂enrichment on green house cucumbers; the thirdpart of this research was focusing on the effect of waste gas CO₂controlled atmosphereStorage on greenhouse tomatoes. Through this study, some important conclusions areobtained as below:1. During the process of industrial waste gas purification by the self-made CO₂fertilizergenerator, when the composition of the absorbing liquid was5%urea,1%Na₂SO₃,0.75%Ca(OH)2, the desulphurization rate stabilized at99.2%⁹9.3%whereas the denitrogenationrate was between67.3%and77.7%, which means the content of SO2and NOx would berestricted below7mg·m^-3and80mg·m^-3, respectively, and they are all complied with thenational standards for emission safety. Therefore, it is feasible to produce CO₂fertilizer viathis route.2. CO₂enrichment by waste gas purification can boost the greenhouse cucumbers'growth in terms of plant height, stem diameter, fruit rate. In the meantime, it can promote theplant leaf's growth by means of number and area increasing. When the content of CO₂enrichment reached2000μmol·mol^-1and the duration of enrichment reached2h/d, the fruitrate can be increased to97.5%, and the average chlorophyll content of cucumber leaf canreach0.976mg·g^-1. 3. CO₂enrichment by waste gas purification can effectively speed up the growth ofgreenhouse cucumber fruits in terms of fruit length and fruit diameter; meanwhile, it can alsoimprove the internal quality of f greenhouse cucumber fruits. When the content of CO₂enrichment reached2000μmol·mol^-1and the duration of enrichment reached2h/d, theharvest of the treated cucumbers was advanced by4d; Meanwhile, the fruit VCand solublesugar content was increased by more than30%and50%, respectively. What's more, Nitratecontent of the fruits was86.09mg· kg^-1, which was complied with the national safetystandard.4. CO₂controlled atmosphere treatment by waste gas purification can effectivelymaintain the tomato fruits' pH, during the25days' storage experiment, the soluble sugar andfluid loss rate of the treated tomatoes reduced by70%and94.5%, respectively. Additionally,the results indicates that, in comparison with the pure CO₂controlled atmosphere treatment,utilization of recovered CO₂will not lead to nitrate content's standard exceeding of the treatedtomatoes.In conclusion, CO₂capture and recycling from industrial waste gas and its agriculturalutilization as CO₂enrichment on greenhouse crops and CO₂controlled atmosphere storage forfruits and vegetables are both of great economic and environmental value, so the technology'sfurther exploration and promotion have extremely vital significance for us.