The talking wall: from the cambrian explosion to the holocene extinction

Protocol for Biodiesel Production from Used Cooking Oils

Introduction

Although they are considered non-hazardous waste, cooking oils discharged into wastewater drainage systems clog the grease filters found in Wastewater Treatment Plants (WWTPs), hindering their proper functioning.

However, reusing frying oils allows for:

• obtaining a derivative that, when mixed with diesel, serves as fuel for, for example, cars – biodiesel;

• using biodiesel directly as fuel in diesel engines;

• making soap;

• reducing the import of petroleum products;

• reducing the emission of polluting particles from diesel engine exhausts.

Materials and Reagents

• Coffee filter

• Used cooking oil

• Methanol

• Sodium hydroxide

• Vinegar

Procedure

Cleaning the used oil

1. Heat approximately 250 ml of used cooking oil to around 40 °C.

2. Filter the hot oil using a coffee filter.

3. Heat approximately 200 ml of filtered cooking oil to around 110 °C to remove any water present.

4. Let the oil cool to a safe handling temperature.

Biodiesel Preparation

1. Measure 200 ml of filtered oil in a graduated cylinder.

2. Weigh 5 g of sodium hydroxide for each liter of oil.

3. Using a graduated cylinder, measure 300 ml of methanol per liter of oil.

4. Add the methanol to the sodium hydroxide and dissolve it completely, then seal the container.

5. Heat the cooking oil to a temperature between 54 °C and 58 °C, add the sodium methoxide solution to the heated oil, and stir for 40 minutes.

6. Let the mixture rest for a day and separate it by decantation using a separating funnel.

Biodiesel Washing

1. Measure the pH of the biodiesel.

2. If the pH is above 7, add a few drops of vinegar (which contains acetic acid) to the washing water.

3. Add water (with vinegar if necessary) to the biodiesel (about 30% of the volume of oil used) and shake.

4. Let it rest for a day and separate.

5. Repeat the washing process until a clear product is obtained.

Guidelines for Group Work on Eras, Eons, and Epochs

The following guidelines are a basis for the development of your group work, which will culminate in the construction of a scaled chronological timeline on a school wall.

Each group should research information from different sources (books, school textbooks, internet) about the assigned Era, Eon, or Epoch, highlighting aspects such as:

• main events;

• representative species;

• events marking the end of the Era, Eon, or Epoch;

• identification of fossils found in each Era, Eon, or Epoch.

The group working on the Holocene may consult the following information sources to write about the present day:

• https://www.theguardian.com/environment/radical-conservation/2015/oct/20/the-four-horsemen-of-the-sixth-mass-extinction

• https://www.theguardian.com/environment/2018/nov/03/stop-biodiversity-loss-or-we-could-face-our-own-extinction-warns-un

• https://www.dn.pt/vida-e-futuro/interior/perda-da-biodiversidade-pode-levar-a-extincao-da-especie-humana-10127224.html

• https://www.publico.pt/2019/05/28/p3/noticia/malasia-morreu-o-ultimo- rinocerente-de-samatra-macho-1874410

This group must also create 4 to 5 sentences that will serve as the basis for the production of “speech bubbles” to be used as support for photographic records on the day of the presentation of the “Talking Wall.” These should contain short phrases or keywords related to the Sustainable Development of the planet. For example: “Think about the planet’s future — act today!”

The focus of this group should be on the challenges the planet faces and the current dangers we are experiencing.

All groups must:

• Select and collect illustrative images, recording their sources;

• Create phrases (maximum two lines) to place on the timeline;

• Write short texts to serve as a “script” for the video recordings to be made.

Fossilization Process Simulation

As you know, fossils are remains of living beings or records of their activity preserved in various materials. This preservation mainly occurs in rocks, but it can also happen in sediments at the bottom of seas and lakes, in ice, in resins, etc.

The most common examples are bones, plants, shells, eggs, and fossilized footprints.

The preservation of organic matter and delicate skeletal remains — since these decompose and are quickly destroyed — requires uncommon fossilization conditions, which occur very rarely.

Adapted from https://pt.wikipedia.org/wiki/F%C3%B3ssil

In this activity, you will simulate the process of fossilization through two different methods, using various materials:

• Plaster

• Water

• Cling film (plastic wrap)

• Dried leaves or sand

• Object (e.g., a small animal toy that fits in the cup)

• Container (plastic cup)

• Stirring stick

• Dropper or squirt bottle

• Tray

• Calcium carbonate to simulate rock material

• Chisel

• Hammer

Each group member must actively participate in carrying out the experimental activities.

Experimental Activity 1

• Label the cups

• Pour in water

• Add plaster

• Mix using the stirring stick

• Wrap the object in cling film

• Place it in the cup until it is submerged

• Wait the necessary time for the water to evaporate

Note: Wrapping the object in cling film helps with its removal in the second part of the activity.

Prediction:

What do you think will happen when the object is removed?

After one week, remove the object by carefully breaking the plaster in half (damaging the impression as little as possible).

Conclusion:

What can you conclude from your observations in this experimental activity?

Experimental Activity 2

• Mix water with plaster/modelling clay thoroughly

• Shape a mold approximately the size of the object

• Wrap the object in cling film

• Press the object into the mold

Conclusion:

What can you conclude from your observations in this experimental activity?

Activity on Major Events in Earth’s History Since Its Origin

1. Carefully read the following historical events, and using the table presented in question 1.1, match each event to the corresponding moment in Earth’s history.

Events:

A) The ozone layer forms

B) The solar system forms

C) Number of species rapidly increases

D) Atmospheric oxygen levels spike

E) Eight planets form, including Earth

F) Amphibians colonize various habitats

G) Unicellular life invades land

H) Earth’s oceans form

I) The supercontinent Pangaea forms

J) Unicellular life appears

K) Multicellular life appears

L) The supercontinent Pangaea breaks apart

M) Photosynthesis begins

N) The Great Extinction

O) First dinosaurs appear

P) Microorganisms begin using oxygen

Q) Greenhouse effect leads to warming and melting

R) Age of dinosaurs

S) Different species of hominids coexist

T) Modern plants and animals appear

U) Dinosaurs go extinct

V) Homo sapiens dominates the planet

W) Homo sapiens appears

X) Hominids use stone tools

Y) Hominids walk upright

Z) Age of Mammals begins

1.1 Record the above historical events in the corresponding spaces provided.