Conceptual design of LED-based hydroponic photobioreactor for high-density plant cultivation.

摘要

A novel hydroponic photobioreactor is proposed for high-density cultivation of plants. Plants are grown on a floating platform, allowing the roots to directly contact a continuously aerated nutrient solution. Growth of Mentha piperita was strongly correlated with light intensity at incident light intensities of 0-650 鎚ol m-2 s-1. For a constant incident light intensity (I0 of 420 鎚ol m-2 s-1), the overall specific growth rates of plants were strongly dependent on plant density, and were in the range 0.023-0.075 per day for plants grown at densities of 16-256 plants/m2. A simple mathematical model is presented that allows one to predict the effects of light intensity and plant density on growth. The relationship between the light extinction coefficient and plant density can be experimentally determined. The light transport can then be coupled with plant growth kinetics under light-limiting conditions. The predicted growth results agree reasonably well with most experimental results from a growthperiod of 17-20 days. On the basis of these simulation results, we suggest that a more efficient way of delivering light to this photobioreactor can be attained by supplying light from both the top and the bottom of the plant shoots. The proposed designtakes advantage of the small size and low weight of light emitting diodes, which allow them to be mounted on platforms for delivering light closer to the plants.