Conductivity

The conductivity in all the six sites is relatively high, between 100mho to 200mho, tap water being the lowest. This measurement suggests a high amount of ions dissolved in the water.

The presence of ions in the Grease Trap may have been caused by detergents and soaps which contained ions such as nitrates and phosphates. The decomposition of organic matter by bacteria to ions (e.g. food molecules) and chemicals that get washed down (e.g. pen ink) would have also contributed to the ionic content in the water.

As the water passes out of the Grease trap and into the phytoremediation system, Organic-Nitrogen is decomposed by bacteria into Ammonia-nitrogen and finally into Nitrate-Nitrogen which flows into the C1 Inlet causing the height in conductivity.

Taken up by the hydroponics, ion concentration decreases in C2 Outlet and Pond 1, resulting in the steady decrease of conductivity as well.

However, conductivity increases in Pond 2. We assume this is caused by the wastes generated by the organisms living in the or due to pollution by the air.