Water Archives - Eva Varga

February 17, 2015

Soil is a complex mixture of minerals, water, air and organic matter that performs many critical functions. In the United States, more than 80 percent of the population lives in cities or suburbs. While the downtown areas of cities are covered with asphalt and concrete, there are still lawns, trees, gardens, and parks. Under all this city space, even under the concrete, is soil.

soilsurbanlifeSoils Support Urban Life

Before we began using pipes, drains, pumps, and other infrastructure to manage stormwater, nature provided the “green infrastructure” to slow, filter, and move water to where it belonged. In forests and wetlands, water is still managed naturally. The foundation of this network is the soil. It is the drain, the pipe, the pump, and the water treatment plant all in one.

As urban areas have grown and we’ve continued to pave over our soils, demands on both natural and manmade stormwater management systems have increased. The last few decades have brought a shift from traditional “capture, convey, and treat” drainage systems. Instead, many cities are beginning to focus on more sustainable systems to manage storm water runoff.

Often referred to as “green infrastructure”, these sustainable systems include rain gardens, living roofs, and the growing trend to plant vegetation native to the region. These practices can delay the arrival of water that reaches the sewer system and thereby reduce flooding.

The biggest benefit green infrastructure, however, is the potential reduction of pollutants entering the storm water system. Pollutants like nutrients (from fertilizers), road salt, and bacteria, can negatively affect aquatic life and public health. Green infrastructure captures these pollutants, especially those that might run off at the beginning of a storm.In both of the cities I have called home in the past few years, a few public buildings have even converted their roof tops to green space. These green roofs not only help to reduce pollutants but provide habitat for pollinators and small birds. In addition, they can provide learning spaces to learn about native plants and sustainable agricultural practices (drip irrigation, etc).

Bring it Home

The Soil Science Society of America recommends that urban dwellers consider rain gardens for their yards and compost their appropriate food wastes. Help the soil serve you by making rain gardens, making and using compost, and making an urban garden. Here are several resources and lesson plans to get you started:

  • Do the Rot Thing – Download this free composting curriculum to bring the science of composting into your curriculum
  • Build a Two-Can Bioreactor or small-scall indoor composting unit, or on a smaller scale consider a …
  • Soda Bottle Bioreactor that will enable students to design and carry out individualized research projects, comparing variables such as reactor design, moisture content, and nutrient ratios of mixtures to be composted.
  • Soil Science – Learn about basic soil science, and then explore some unique characteristics of soils found in urban areas.
  • Exploration of Run-off and Infiltration – In this unit, students design and conduct experiments on runoff and infiltration, either outside or in the classroom
  • Nourishing the Planet – Download the free soil science curriculum to help students realize the challenges of feeding a growing world
  • Dig It! Secrets of Soil – Visit the Smithsonian exhibit’s website to access 10 online interactive learning modules

January 13, 20121

Young children learn best through hands-on science, or simply “doing.” They learn about the world around them primarily by experiencing it through their senses.

For this reason it is important to focus science lessons around things that they can see, hear, touch, taste, and smell. Late last week, we began a chemistry unit.

I don’t believe I have seen the kids more excited about a subject before. Particularly my daughter who just two days ago checked out four books on specific elements, a fun introductory book on the periodic table, as well as a book of fun experiments. She has already read 3 of them!

Electrolysis of Water

One of the first experiments we undertook enabled us to observe the electrolysis of water; separating the elements in water (hydrogen and oxygen) into their gaseous state.  

The setup was very simple and the kids were ecstatic with what they observed.  We had to look closely, as the bubbles were small, but we indeed could see the accumulation of oxygen gas (O2) and hydrogen gas (‎H2) on the electrodes. Note: we used two pencil lead refills, a polymer carbon, not the element we know of as lead).

As we all know, the chemical formula for water is  ‎H2O. This means there are twice as many hydrogen molecules as oxygen molecules.  When electricity is introduced to water, the molecules split with hydrogen gas (H2) appearing at the cathode.  Since there are more hydrogen molecules than oxygen molecules in water, the electrode that the hydrogen collect upon will have more bubbles.

I asked them to draw their observations in their science journals and their enthusiasm for the subject carried over. Labels, measurements, and careful diagrams were encouraged. I love that they used the chemical symbols for the elements.

Further Exploration

As they are young yet, I didn’t discuss with them the process of reduction or oxidation.  Our focus was simply to understand that by passing a current of electricity through the water, we could separate the atoms of water to get a pure element.  

I have been reading aloud Kathleen Krull’s Marie Curie (Giants of Science). Through much of the book, the author discusses how Marie and her husband Pierre worked tirelessly to isolate radium from a complex compound called Pitchblende.  This simple electrolysis experiment gave the kiddos a small window through which they could understand this process.

For another easy experiment with water, I encourage you to check out Ashley Mullen’s, Walking Water Experiment. Discover the colorful magic of capillary action.

A great book to get kids excited about chemistry is The Periodic Table: Elements with Style! The periodic table shows us the building blocks for every substance in the world. This book is written in a simple and humorous style with great illustrations. It is interesting to me as an adult and simple enough for beginning readers to read independently. 

Science concepts can be introduced early. With each exposure, students will gradually develop a greater understanding of how the world around them works.