Section 1 : Overview

We have designed a silicon absorption column to effectively absorb the Si-tag along with the engineering bacterium and the rare-earth element. Compared with common absorption columns, our column boasts two special features: stratification and access-control. Through stratification, we are able to analyze the absorption rate in different depths. We can also decide the amount of quartz sand we add through the stratification strategy. On the other hand, with the help of access-control, we could store the wastewater for as much time as we want to. This helps the silicon combine more bacteria, and at the same time, more rare-earth elements. Finally, a sterilization chamber at the exit ensures that no engineered bacteria can escape into the environment. On the whole, the silicon absorption column helps us conduct our experiment more effectively and precisely.

Section 2 : Structure

2.1 The top entrance

The top entrance is placed at the top of the silicon adsorption column. It protects the top layer of the container and acts as a funnel when we pour in the wastewater. It is designed in a regular hexagon to represent the appearance of “silicon”. The hexagon design also enables more stable assembly.

2.2. The column body

The column body connects the top entrance and the base. It also supports the top entrance and props up the six silicon containers. It is designed in a regular hexagon to prevent slipping from the base and maximize space utilization at the same time. There are six pairs of horizontal-chink holders on two sides of the column body. These holders prop up the silicon containers. At the same time, there are two vertical-chink passageways. To assemble a container onto the column body, one needs to first slip the container down the vertical-chink passageways, and then rotate it along the horizontal-chink holders. The ‘stairs’ at the end of the horizontal-chink holders then stuck the container at a fixed position.

2.3. The containers

There are in total six containers. They are designed to contain the quartz sand. The handles on the opposite sides of the containers are inserted into the horizontal-chink holders (as shown in the column body part). Each container could stack up onto another container. When all the containers stack up together, an airtight pipeline is formed. The pipeline is where the waste water is stored and the adsorption takes place.

To contain the sand, a layer of Nylon mesh is stick to the inside of the container. This is done in our actual product but not in our schematic diagram.

2.4. The base

The base function as supporting the whole column and at the same time props up the water valve. The regular hexagon on the top docks with the column body. Meanwhile, the circle on the top docks with the container at the bottom.

The horizontal-chink holder of the base supports the handles of the water valve, enabling it to rotate smoothly to open or close the valve. The vertical-chink holder function as a passageway for assembling the water valve.

2.5. The water valve

The valve helps us control the storage and release of the waste water. Under storage mode, the open fan-shaped hole aligns with the non-open part of the container, preventing the waste water from leaking. Under release mode, the open fan-shaped hole aligns with the open hole of the container, allowing the waste to leak down the column. Through simply rotating the valve, one can switch between the two modes, helping make the experiment more convenient.

Section 3 : Complete steps to use the column

a) Assemble the water valve into the base and place the column body on the base. Remember to rotate the valve to the end.

b) Decide how many layers of silicon you want to use and fill these layers with Quartz Sand.

c) Assemble all the layers into the column body in order. Remember to place the layers with Quartz Sand on the bottom and the layers without Quartz Sand on the top.

d) Cover the column with the top entrance. Now, you can add the waste water into the column and wait for the adsorption according to the time you’ve set for the experiment.

e) To analyze the adsorption rate, you first need to release the water. It is easy to do so: just rotate the valve away from the end and the water will release from the bottom soon. Don’t forget to place a container to take the released water!

f) It’s time for harvest! You can disassemble the layers and analyze the adsorption effects!