Passive Xylem Filter for Bacterial Elimination from Wastewater

Overview

Objectives/Goals The purpose of my study is to examine passive flow, without applying vacuum or suction, through xylem (microscopic tubes inside the branch) filters using both Pine (gymnosperm) and Eucalyptus (angiosperm) tree branches to build a low-cost filter to make contaminated water safe to drink Methods/Materials Materials: Pine and Eucalyptus Tree branches, PVC Tubing, Metal Pipes, Epoxy, Plumbers Tape, Probiotic Capsules (Lactobacillus, Bifido, Streptococcus) to make contaminated water, Shelving unit, Clamps, Bacteria Enrichment Tubes, Bacteria Detection Tubes, Luminometer, Incubator, Digital Scale Methods: Different filters were constructed using a wood chip at the end of a PVC tube or a metal pipe to measure water flow and bacterial elimination from contaminated water. Contaminated water was created using probiotic capsules with lactobacillus and bifido bacteria species. Pre-filtration bacteria sample from the top of each filter was taken as well as sample post-filtration. The samples were placed in the enrichment device into the incubator set at 30 degrees C for 7 hours. The samples were then placed in a detection tube inside luminometer and relative light unit (RLU) reading were recorded correlating to bacteria colony counts. Results To understand the difference between pine and eucalyptus filters, I calculated permeability (variable k) of my filters using Darcy#s equation for flow through a porous membrane. I had measured flow rate, could calculate area of the wood piece, had the filter length, and calculated the pressure gradient based on the height of the water in the pipe (equivalent to the length of the pipe above the wood). My permeability (k) for pine was .02 kg/m s MPa and was.33 kg/m s MPa for Eucalyptus. Most of my second and third generation filters eliminated about 40%-99.7% of the bacteria. I observed that with sufficient resistivity (determined by area and length of the wood chip, Eucalyptus (Angiosperm) can be as effective as Pine (Gymnosperm). This property of the wood chip is linked to its ability to clear bacteria. Conclusions/Discussion Eucalyptus had much higher flow, without application of any vacuum or suction, and once we found the right length and permeability of Eucalyptus inserted into a filter design with no leakage, we found it to be as good as pine wood in eliminating 97%-100% of bacteria and making water contaminated with bacteria safe to drink.

Competition history

• CSEF 2017 Environmental Engineering · Entry J1103

Resources

• CSEF project summary ↗

Related projects

Closest projects by meaning, across every fair and year in the corpus.

Browse more like this

• All Environmental Engineering projects
• CSEF Environmental Engineering projects
• Every CSEF 2017 project