Optimization of Response to Light
Various aspects provide for exposing a substance to light. Certain aspects include exposing a suspension of photosynthetic organisms to sunlight, and may include optimizing exposure to improve photosynthesis conditions. Certain embodiments include controlling an opacity or opacity profile of a suspension of algae and/or diatoms. Optimizing exposure may include maximizing growth rate, maximizing photosynthesis efficiency, maximizing lipid production, minimizing damage, minimizing predator growth, maximizing a capacity to grow in suboptimal media (e.g., polluted water, brackish water, or water having a pH outside of a preferable range), minimizing requirements for nutrients, and other features.
1 . A method for exposing a suspension to light, the method comprising:
determining an intensity of the light;
determining an opacity of at least a portion of the suspension; and
adjusting the opacity in response to the intensity.
2 . The method of claim 1 , wherein the suspension includes a liquid and a plurality of photosynthetic organisms.
3 . The method of claim 2 , wherein adjusting the opacity includes adjusting a concentration of the organisms in the liquid.
4 . The method of claim 3 , wherein adjusting the concentration includes diluting the suspension.
5 . The method of claim 2 , wherein adjusting the opacity includes evaporating at least a portion of the liquid.
6 . The method of claim 1 , wherein adjusting the opacity includes altering a flow pattern associated with the suspension.
7 . The method of claim 2 , wherein adjusting the opacity includes segregating the suspension into regions having different concentrations of the organisms in the liquid.
8 . The method of claim 7 , wherein the segregated suspension includes a top region having a higher concentration than a bottom region having a lower concentration.
9 . The method of claim 2 , wherein the suspension includes one or more diatoms.
10 . The method of claim 2 , wherein the suspension includes one or more algae.
11 . The method of claim 10 , wherein any of the algae includes a member of the genus Nannochloropsis.
12 . The method of claim 2 , further comprising determining a property of the organisms.
13 . The method of claim 12 , wherein the property includes a response to the light.
14 . The method of claim 13 , wherein the property includes an integrated response to the light over a period of time during which the suspension was exposed to the light.
15 . The method of claim 12 , wherein the property includes a photosynthetic efficiency of the organisms.
16 . The method of claim 12 , wherein the property is associated with a Photosystem II response.
17 . The method of claim 12 , wherein the property includes a capacity of the organisms to perform photosynthesis.
18 . The method of claim 12 , wherein the property includes a photochemical quenching characteristic of the organisms.
19 . The method of claim 18 , wherein the property is associated with a Photosystem I response.
20 . The method of claim 12 , wherein the property includes a damage parameter associated with damage to the organisms.
21 . The method of claim 20 , wherein the damage at least partially results from an exposure to the light.
22 . The method of claim 20 , wherein the property includes a photoinhibition response.
23 . The method of claim 12 , wherein determining the property includes sampling a plurality of points within the suspension.
24 . The method of claim 23 , wherein two or more points in the plurality are characterized by different intensities of exposure to the light.
25 . The method of claim 2 , wherein the adjusted opacity maximizes an exposure of the organisms to an intensity corresponding to an efficiency threshold.
26 . The method of claim 2 , wherein the adjusted opacity minimizes an exposure of the organisms to an intensity above a damage threshold.
27 . The method of claim 1 , wherein adjusting the opacity includes adjusting a distance between a top and a bottom of the suspension.
28 . The method of claim 1 , wherein the suspension is characterized by a concentration of a suspended phase in a liquid, and a first concentration prior to adjusting the opacity is different than a second concentration after adjusting the opacity.
29 . The method of claim 1 , wherein determining the intensity includes measuring the intensity.
30 . The method of claim 29 , wherein the intensity is measured at one or more points within the suspension.
31 . The method of claim 29 , wherein the measured intensity includes an incident intensity.
32 . The method of claim 29 , wherein the measured intensity includes a reflected intensity.
33 . The method of claim 32 , wherein the reflected intensity includes reflection from the bottom.
34 . The method of claim 1 , wherein the suspension comprises a liquid and a suspended phase, and determining the opacity includes:
determining a concentration of the suspended phase in the liquid; and
calculating the opacity based on the concentration.
35 . The method of claim 1 , wherein determining the opacity includes measuring the opacity.
36 . The method of claim 1 , wherein the determining the opacity includes determining the opacity at a plurality of points within the suspension.
37 . The method of claim 1 , wherein determining the opacity includes determining an opacity profile in a first direction.
38 . The method of claim 37 , wherein the first direction is within 45 degrees of an incident direction associated with the light.
39 . The method of claim 37 , wherein the first direction is within 45 degrees of a reflected direction associated with a reflection of the light from a bottom of the suspension.
40 . The method of claim 1 , wherein determining the intensity includes measuring the intensity.
41 . A system comprising:
a pond configured to contain a suspension at a depth, the suspension comprising a suspended phase and a liquid;
a first inlet configured to deliver the suspension to the pond; and
a sensor to measure an intensity of light within the pond.
42 . The system of claim 41 , further comprising a second inlet to deliver the liquid to the pond.
43 . The system of claim 41 , wherein the sensor is configured to measure an incident intensity of the light.
44 . The system of claim 41 , wherein the sensor is configured to measure a reflected intensity resulting from a reflection of the light from a bottom or side of the pond.
45 . The system of claim 41 , further comprising a depth gauge configured to measure a distance between a bottom of the pond and a top surface of the suspension.
46 . The system of claim 41 , wherein the sensor is disposed within the delivered suspension.
47 . A system comprising:
a pond having a bottom and sides and configured to contain a suspension at a depth and expose the suspension to light having an incident intensity, the suspension comprising a suspended phase and a liquid, the suspension having an opacity to the light that results in at least a first portion of the suspension being characterized by a reduced intensity of the light within the first portion, the reduced intensity below a damage threshold associated with the suspended phase.
48 . The system of claim 47 , wherein the opacity results in at least a second portion of the suspension being characterized by a recovery intensity of the light within the second portion, the recovery intensity below a recovery threshold associated with the suspended phase.