Method for biofloculating microalgae by using glycine

Abstract

The invention discloses a method for biofloculating microalgae by using glycine, which comprises the following steps: adding glycine into a microalgae culture solution, sufficiently stirring, continuing culture, regulating the pH value of the culture solution, standing until the microalgae flocculates and the culture solution stratifies, and separating the microalgae biomass, thereby achieving the goals of dehydration and collection. The glycine used as the flocculant is utilized to stimulate the microalgae to secrete a viscous extracellular polymer with three-dimensional space structure which can wrap the microalgae cells, thereby achieving the goal of floculation. The dehydration rate can reach more than 90%, and the biomass recovery rate is up to 70-90%. Besides, the glycine is nontoxic and harmless, can not destroy the water quality, and can be used as an organic nitrogen source and carbon source to be absorbed and utilized by the microalgae cells so as to promote the continuous growth of the microalgae, thereby achieving the goal of cyclic utilization of the culture solution. Therefore, the method can lower the microalgae culture and collection cost, is simple to operate and simple in technique, and is suitable for industrialized collection of the microalgae biomass.

Description

technical field [0001] The invention belongs to the field of bioengineering, and in particular relates to a bioflocculation method using glycine microalgae. Background technique [0002] Most of the current industrial microalgae cultivation adopts raceway ponds, tubular reactors, flat plate reactors and other methods. Microalgae harvesting methods include centrifugal dehydration, filtration dehydration, flocculation dehydration, air flotation dehydration and sedimentation dehydration. Since microalgae is a single-celled microorganism with a cell diameter of only 5-20 μm and a culture density of 0.5-2 g / L, dehydration by centrifugation and filtration requires a large investment in energy and equipment costs, which virtually increases the cost of microalgae. The cost of large-scale utilization. However, the effects of air flotation dehydration and sedimentation dehydration are poor. Flocculation refers to adding a flocculant to the microalgae stock solution to neutralize th...

AI Technical Summary

Problems solved by technology

However, the disadvantage of polymer flocculation is that the price of the polymer is relatively high, and because the molecular weight of the polymer is large, the amount of flocculant added is also large

pH flocculation is to strengthen the neutralization of cations in the culture medium to the negative charges on the surface of algae cells through pH adjustment. The advantages are low price, avoiding water resource damage and impact on target products, and the disadvantages are low flocculation efficiency and poor dehydration effect

[0003] In order to reduce equipment investment and energy consumption in the process of harvesting microalgae, avoid damage to the water quality of the culture solution, and solve the problem of recycling the culture solution, the present invention provides a method for flocculation of organic matter, that is, by using an organic Carbon source glycine (C 2 h 5 NO 2 ) as a flocculant, using glycine to stimulate microalgae to secrete a viscous extracellular polymer with a three-dimensional space structure, and wrap the algal cells to achieve the purpose of flocculation

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