Merry Christmas and Happy New Year from Green Sligo

Green house Effect and Global warming

Thermochemistry

This will help you with some Physics as well!

Water Treatment and Laws

Clean drinking Water is a basic Human Right. Unfortunately not all people avail of this, for example in parts of Galway residents still have to boil water due to the threat of ecoli.


Water purification is the process of removing undesirable chemicals, materials, biological contaminants from contaminated water. Most of our water comes from rivers and lakes. It is necessary to treat the water for human consummation. This is done in a treatment plant. There are different stages involved before water can come out of your tap.

• Pre-chlorination - for algae control and arresting any biological growth
• Aeration - along with pre-chlorination for removal of dissolved iron and manganese
• Coagulation - for flocculation
• Coagulant aids, also known as polyelectrolytes - to improve coagulation and for thicker floc formation
• Sedimentation - for solids separation, that is, removal of suspended solids trapped in the floc
• Filtration - removing particles from water
• Desalination - Process of removing salt from the water
• Disinfection - for killing bacteria.

The EPA, HSE, and EU Drinking water directors composed regulations for Drinking Water: Here are a few examples.

• 200 microgrammes per litre (µg/L) of water must only be present in drinking water.
• 4 parts per million (ppm) of Chlorine is the recommended amount for drinking water. 
• 25 microgrammes per litre (µg/L) of lead is the recommended amount in drinking water.

This link is the complete guidelines on drinking water:

http://ec.europa.eu/environment/water/water-drink/index_en.html

• Pre-chlorination - for algae control and arresting any biological growth
• Aeration - along with pre-chlorination for removal of dissolved iron and manganese
• Coagulation - for flocculation
• Coagulant aids, also known as polyelectrolytes - to improve coagulation and for thicker floc formation
• Sedimentation - for solids separation, that is, removal of suspended solids trapped in the floc
• Filtration - removing particles from water
• Desalination - Process of removing salt from the water
• Disinfection - for killing bacteria.

Balancing Chemical Equations

Chemistry Support by Green Sligo

We all know chemistry is not everybody's biggest thing but we have to get through with that subject to understand chemistry when Environmental issues occur
The Khan academy is a very useful web site to get some support at chemistry. You will find video clips about periodic table, ionic and covalent bonds, balancing chemical equations, the mole & the Avogadro's number and so on. This web site is also helpful at maths and biology. Have a look at khan academy and get your own opinion about it.


http://www.khanacademy.org/#Chemistry 

Chemistry for the Environment

Chemistry is very important! It is widely used by Environmental Scientists and Environmental Protection Officers.


What Chemistry will you use?
You will use various types of Chemistry!
pH is the measure of acidity of a substance. It is used in the measuring of the acidity/alkalinity of a river, lake or soil. The following is a review of the experiment conducted in the lab which is commonly used by Environmental Scientists/Protection Officers


Title
Determination of Dissolved Oxygen (DO), Percentage Saturation (%Sat), temperature and pH in river water.


Date
30/11/2010


Objective
The purpose of this experiment is to examine two samples of river water. DO Meters are used to measure DO and %Sat. pH meters are used to measure pH and temperature. The two samples are compared.


Materials

• Two River samples: Sample A and Sample B (One upstream and one lower stream)
• Dissolved Oxygen Meter (DO and %Sat)
• pH Meter (pH and temp)

Method

1. Two samples of river water are taken. One is taken from upstream, another from lower stream.
2. Beakers are labelled 'Sample A' and 'Sample B'
3. DO Meters are put into Sample A to measure DO and %Sat.
4. Record Data.
5. A pH meter is used to to measure pH and temperature.
6. Record Data.
7. The same is done for Sample B.

Results

NOTE: The following results are examples and are NOT suitable results.

Sample	DO (mg/L)	%Sat	pH (6.5 → 8)	Temp (°C)
Sample A	9.84 mg/L	89.10%	7.45	10.1°C
Sample B	10.12 mg/L	90.25%	7.55	10.09°C

Conclusion


From the results above we can tell that the river water quality in this river is quite good. From Sample A we can see that it is suitable for salmon. Salmon require 7-9 mg/L of Oxygen. The percentage Saturation is good. It is recommended that it is 100%. Because  Sample A was taken from upstream with a low rate of flow therefore the percentage saturation is lower than the recommended. The pH is good. The temperature for this time of year is on average temperature is 12°C, this is below average. This can  be because of the recent cold weather,snow and ice. Overall the quality of water in the river is quite good and meets EU regulations.


Discussion


What are the errors of under going this experiment?
From the minute of taking the samples to the conclusion of the experiment certain errors may have accord. When the samples are taken and placed into a beaker the temperature of the water may begin to change. Your hands slowly begin to heat the water. The Oxygen levels could change due to more oxygen being present in the new environment. It is very important that as soon as the samples have been taken that the experiment is undergone.

DO Meter kit