Question

Textile mills often release dye color and toxic by-products into rivers and streams, which may then taint groundwater. Fungi associated with mangrove trees have been shown to reduce both colors and toxicity in tainted groundwater.


Suppose that fungal treatment was added to stream water contaminated from a textile mill. The toxins in the water tend to lower pH levels, and scientists wanted to study how adding the fungal treatment affected stream pH levels. pH levels were recorded every year for five years. Results indicated that the acidity of the stream water decreased from pH 2.5 in the first year to pH 5.9 by the fifth year. Scientists concluded that

Answer 1

The value of decreasing pH indicates that the concentration of H+ ions released in the stream of contaminated water were increased due to the fungal treatment. This affected the acidity of stream of water indicating a decrease in the acidity on a pH level from 2.5 in the first year to 5.9 by the 5th year. This occurs due to the effect on fungal ecosystem of the water stream. The fungus reacted with the acidic water stream feeding on its components to release more H+ ions during the metabolism. Thus over 5 years the ultimate result is a change of pH from 2.5 to 5.9.