Environmental Sciences Fair Project
Which green materials filter water better?


Projects by Grade Level
1st 2nd 3rd 4th 5th 6th
7th 8th 9th 10th 11th 12th
Home Advanced Award Winning Warning!
Project Information
Title: Which green materials filter water better?
Subject: Environmental sciences
Subcategory: Water quality
Grade level: Middle School - Grades 7-9
Academic Level: Ordinary
Project Type: Experimental
Cost: Low
Awards: 1st place, Canada Wide Virtual Science Fair ($300)
Affiliation: Canada Wide Virtual Science Fair (VSF)
Year: 2014
Materials: Distilled Water, cow manure, Playbox sand, aquariam gravel, rice husk, coffee grinds, tea leaves, coconut coir, terra cotta clay, 2 L plastic soft drink bottles
Description: Nearly 1 billion people in developing countries do not have access to clean water. In India, 1 nearly one million children die each year from drinking water that contains coliform bacteria. 2L drinking bottles were used to construct water filters including a layer of sand and a layer of aquarium gravel. Between the layers were inserted different green materials like coconut coir, rice husk ash, terracotta disk made with rice husk, terracotta disk made with tea leaves, and terracotta disk made with used coffee grinds. Then the water filtered from the different experiments was tested for the amounts of coliform, turbidity, phosphate, pH, and nitrate and the results were compared.
Link: www.virtualsciencefair.org...
Background

Water filter

A water filter removes impurities from water by means of a fine physical barrier, a chemical process or a biological process. Filters cleanse water to different extents for purposes like irrigation, drinking water, aquariums, ponds and swimming pools.

Filters use sieving, adsorption, ion exchanges, biological metabolite transfer, and other processes. Unlike a sieve or screen, a filter can remove particles much smaller than the holes through which the water passes.

Water filters can be made on-site using local materials such as grass, charcoal (e.g. from firewood burned in a special way). These filters are sometimes used by soldiers and outdoor enthusiasts. Due to their low cost they can be made and used by anyone. The reliability of such systems is highly variable. Such filters can do little, if anything, to mitigate germs and other harmful constituents and can give a false sense of security that the water so produced is potable. Water processed through an improvised filters should be undergo secondary processing such as boiling to render it safe for consumption.

Slow sand filters are used in water purification for treating raw water to produce a potable product. They are typically 1 to 2 metres deep, can be rectangular or cylindrical in cross section and are used primarily to treat surface water. The length and breadth of the tanks are determined by the flow rate desired by the filters, which typically have a loading rate of 0.1 to 0.2 metres per hour (or cubic metres per square metre per hour).

Slow sand filters, due to their simple design, may be created DIY. DIY-slow sand filters have been used in Afghanistan and other countries to aid the poor.

Simple techniques for treating water at home, such as chlorination, filters, and solar disinfection, and storing it in safe containers could save a huge number of lives each year. Reducing deaths from waterborne diseases is a major public health goal in developing countries.

A Biosand Filter (BSF) is a point-of-use water treatment system adapted from traditional slow sand filters. Biosand filters remove pathogens and suspended solids from water through a combination of biological and physical processes that take place in a sand column covered with a biofilm. BSFs have been shown to effectively remove heavy metals, turbidity and other contaminants such as bacteria, viruses and protozoa. BSFs also help to reduce discoloration, odor and unpleasant taste. Studies have shown correlation between use of BSFs and decrease in occurrence of diarrhea with an increase in general health. Due to their effectiveness, ease of use, and lack of recurring costs, biosand filters are often considered appropriate technology in developing countries. It is estimated that over 200,000 BSFs are in use worldwide.

Biosand filters are typically constructed from either concrete or plastic. The most widely used plans for the concrete biosand filter are produced and distributed by CAWST, and Hydraid Biosand Water Filter. Most biosand filters consist of similar components. At the top of the filter there is a tightly fitted lid, which prevents contamination and unwanted pests from entering the filter. Below is the diffuser plate, which prevents disturbance of the biofilm when water is poured into the filter. Water then travels through the sand column, removing pathogens and suspended solids. Below the sand column is a layer of gravel that prevents sand from entering the drainage layer and clogging the outlet tube. Below the separating layer is the drainage layer, which consists of larger gravel that promotes water flow by preventing clogging near the base of the outlet tube.

The Tata Swach is a water purifier developed by Tata Chemicals, a part of the Tata group in India. Swach was designed as a low cost purifier for Indian low-income groups, who lack access to safe drinking water.

Sujal was a very basic low-cost model which used rice-husk ash (produced from heating rice husk in combination with pebbles and cement). Activated silica and carbon is present in the ash; silica can reduce the turbidity of water, while activated carbon binds with and adsorbs non-polar impurities (such as pesticides and fertilisers).

Soma is a company that designs eco-friendly water filtration systems. The filters are made from Malaysian coconut shells, vegan silk, and food-based PLA plastic.

See also:
Water Filter
Water Purification
Tata Swach
Soma Company

Source: Wikipedia (All text is available under the terms of the Creative Commons Attribution-ShareAlike License)

Useful Links
Science Fair Projects Resources
Citation Guides, Style Manuals, Reference
General Safety Resources
Electrical Safety FAQ
Environmental Sciences Fair Projects

Ecology Science Fair Projects

Environmental Sciences Experiments
Books

         



Projects Home
Primary School
Elementary School
Middle School
High School
Advanced
Easy Projects
Award Winning
Popular Ideas
Branches of Science
Experiments

Science Fair Project Guide
Home
Science Fair Project Types
The Scientific Method - How to Experiment
The Display Board
Topics, Ideas, Sample Projects

Repeat Famous Experiments and Inventions
Science Jokes Science Trivia
Scientists & Inventors

Read for Free
The Science Fair
A Juvenile Science Adventure Novel
by Julian T. Rubin

Human Abridged Wikipedia Articles



My Dog Kelly

Follow Us On:
     

Privacy Policy - Site Map - About Us - Letters to the Editor

Comments and inquiries:
webmaster@julianTrubin.com


Last updated: January 2018
Copyright © 2003-2018 Julian Rubin