Siti

Site: Tap Water

The tap water (which is chlorinated to remove any harmful bacteria and viruses) is supplied to the restroom's sink to be used by female teachers to wash dirt away from body parts and any equipment used. Tap water is well treated and can be used for consumption as it is safe. After washing, used tap water containing mainly soaps, grease and bacteria will be washed down, through the pipes and into the the grease trap.

• Environmental & Chemistry Analysis Lecture Notes
• http://www.asiaone.com/News/Education/Story/A1Story20080711-76164.html
• http://www.britannica.com/EBchecked/topic/424285/ocean/67070/Dissolved-organic-substances#tab=active~checked%2Citems~checked&title=ocean%20%3A%3A%20Dissolved%20organic%20substances%20--%20Britannica%20Online%20Encyclopedia
• http://www.hc-sc.gc.ca/ewh-semt/pubs/water-eau/nitrate_nitrite/index-eng.php
• http://www.ktf-split.hr/glossary/en_o.php?def=dissolved%20substance
• http://www.britannica.com/EBchecked/topic/424285/ocean/67070/Dissolved-organic-substances#tab=active~checked%2Citems~checked&title=ocean%20%3A%3A%20Dissolved%20organic%20substances%20--%20Britannica%20Online%20Encyclopedia
• http://gardening.about.com/od/amendingsoil/g/Organic_Matter.htm
• http://www.pub.gov.sg/general/Pages/WaterTreatment.aspx
• www.dictionary.com
• Douglas Bowman - Blogskin
• Tan Wei Hao – for site map
• Cheryl - for being our unpaid model :)
  

Site: Grease Trap

There are 3 parts of the Grease Trap. The 3 compartments are separated by 2 filters that function as membrane to filter the water and prevent dirt and grease from entering the next site.

In the 1st compartment, big molecules, such as hair and food, are prevented from passing through the membranes and into the 2nd compartment.

In the 2nd compartment, smaller molecules, such as dirty foams from hand wash, are prevented from entering the 3rd compartment.

Finally, in the 3rd compartment, even smaller molecules, such as oils, are prevented from entering the next part of the water treatment system which is the phytoremediation system.

Nitrate vs Nitrite

The graph shows that there is a strong relation between the nitrates and nitrites concentration in the waters of the sites, Tank before Pond not included. This was mainly caused by the similar values of the nitrate and nitrites concentrations that remained mostly in the same range as shown by the table. Thus, the relation between these ions are insignificant.

The maximum acceptable concentration (MAC) for nitrate & nitrite in drinking water is 45 mg/L & 3.2mg/L respectively. Given that our average values for nitrate & nitrite is 0.0838mg/L & 0.0186mg/L respectively, this shows that the water is usable as potable water & for domestic purposes.

The nitrate value increases as its sources in water includes breeding of tadpoles and fishes, especially in the ponds. Their wastes (that contained organic-nitrogen) would have contributed to the increase in nitrate. The nitrite value is low as it is only formed by drinking water distribution systems that use chloramines, such as tap water. Only under anaerobic conditions, nitrate may be degraded to nitrite.

http://www.hc-sc.gc.ca/ewh-semt/pubs/water-eau/nitrate_nitrite/index-eng.php

DO vs BOD

The higher the BOD, the lower the DO present in the sample. This is caused by the organisms thriving in water, especially bacteria in polluted water such as the Grease Trap. And since the organisms in the waters require high amount of Oxygen for their activities, it results in the decrease of DO.

Given that the values of BOD are 4.75mg/L in average, it falls into the standard values of BOD of Raw Water source which is 3 to 15 mg/L.

DO vs TEMPERATURE

The higher the temperature of the sites, the lower the Dissolved Oxygen (DO). This is due to several reasons:

1. The solubility of oxygen varies with temperature. The concentration of Oxygen in the water is inversely proportionate to the temperature.
2. Due to high temperature (28 degrees Celcius), organisms such as tadpoles, planktons, plants and bacteria in the water require higher amount of DO to respire and carry out their activities as per normal.

Our results, however, shows a weak relation between these two parameters. This was probably due to experimental errors in measuring the temperature and DO values on site. Instead of dipping the DO cum Temperature probe into the water bodies, we collected samples from the sites into bottles before measuring them. The samples were left in the bottles for a length of time before they were measured for their temperature and DO values.

Hence, we can assume that some of the DO had escaped into the atmosphere and that the temperature had changed slightly when we tested them, causing varied or inaccurate values.

Conductivity vs TDS

There is a strong and significant relationship between the conductivity and total dissolved solids content of the different sites.

Both of theses parameters are co-related as Conductivity measurement is able to conduct a quick estimation on the amount of the Dissolved Solids (DS).The TDS content of the waters had consisted of ions that contributed to the electrical conductivity of the waters. They mainly came from the various kinds of dissolved substances such as detergent, soap, oils and bacteria from hands and face.

Hence, from the graph, we find that as the content of total dissolved solids increases, the conductivity of the water increases as well.

http://www.britannica.com/EBchecked/topic/424285/ocean/67070/Dissolved-organic-substances#tab=active~checked%2Citems~checked&title=ocean%20%3A%3A%20Dissolved%20organic%20substances%20--%20Britannica%20Online%20Encyclopedia