Clean Lakes Case Study
Do clean lakes really exist?
By Yujia, Luo (Group 1)
September, 2014
Introduction
A main purpose of wastewater and sludge treatment is to remove phosphorus (P). It seems to be reasonable because excess phosphorus entering the aquatic systems can result in algal blooms. People have been taking much effort to explore simple, economic and high effective methods to remove phosphorus. Concentration of nitrogen (N) is another important element to assess the quality of freshwater. As the same with phosphorus, excess nitrogen also leads eutrophication. But it’s more difficult to prevent lakes from being nitrogen-rich, because managing nitrogen input isn’t as easy as phosphorus, especially with respect to the non-point nitrogen inputs, including nitrate …show more content…
Lakes’ nitrogen removal capability is not only affected by nitrogen load and water residence time (Finlay, J.C. et al., 2013), but also be affected by phosphorus in lakes. Increased phosphorus concentration stimulates algal growth, which leads to increased inorganic nitrogen being assimilated into tissue of algal blooms. When alga dies, these organic nitrogen will be transported into the sediments where are lack of oxygen. As a consequence, denitrification process is increased, leading more nitrogen convert to N2 and N2O entering atmosphere. If phosphorus supply decreased, algal production will be reduced, and then denitrification process will be significantly and negatively influenced. Therefore, estuaries and coastal waters where nitrogen is the limited nutrition for alga, facing the risk of being eutrophic by N-rich downstream …show more content…
(2013) claims that phosphorus pollution has positive impacts on nitrogen removal rate and efficiency, and cleaner lakes are actually dirtier lakes. For his perspective, phosphorus pollution is a good friend to lakes. It’s not easy to say whether he is right or wrong, as we can’t easily advocate SO2 is totally harm for environment and human beings. SO2 contributes to acid rain, which erodes architecture, agriculture and forests. This irritative gas also significantly affects human health (lung and liver function). However, SO2 has negative impacts on radiative forcing because SO2 emissions lead to aerosols, which reflect sunlight and so alter the radiative balance. As a consequence, SO2 has positive impacts on climate
By Yujia, Luo (Group 1)
September, 2014
Introduction
A main purpose of wastewater and sludge treatment is to remove phosphorus (P). It seems to be reasonable because excess phosphorus entering the aquatic systems can result in algal blooms. People have been taking much effort to explore simple, economic and high effective methods to remove phosphorus. Concentration of nitrogen (N) is another important element to assess the quality of freshwater. As the same with phosphorus, excess nitrogen also leads eutrophication. But it’s more difficult to prevent lakes from being nitrogen-rich, because managing nitrogen input isn’t as easy as phosphorus, especially with respect to the non-point nitrogen inputs, including nitrate …show more content…
Lakes’ nitrogen removal capability is not only affected by nitrogen load and water residence time (Finlay, J.C. et al., 2013), but also be affected by phosphorus in lakes. Increased phosphorus concentration stimulates algal growth, which leads to increased inorganic nitrogen being assimilated into tissue of algal blooms. When alga dies, these organic nitrogen will be transported into the sediments where are lack of oxygen. As a consequence, denitrification process is increased, leading more nitrogen convert to N2 and N2O entering atmosphere. If phosphorus supply decreased, algal production will be reduced, and then denitrification process will be significantly and negatively influenced. Therefore, estuaries and coastal waters where nitrogen is the limited nutrition for alga, facing the risk of being eutrophic by N-rich downstream …show more content…
(2013) claims that phosphorus pollution has positive impacts on nitrogen removal rate and efficiency, and cleaner lakes are actually dirtier lakes. For his perspective, phosphorus pollution is a good friend to lakes. It’s not easy to say whether he is right or wrong, as we can’t easily advocate SO2 is totally harm for environment and human beings. SO2 contributes to acid rain, which erodes architecture, agriculture and forests. This irritative gas also significantly affects human health (lung and liver function). However, SO2 has negative impacts on radiative forcing because SO2 emissions lead to aerosols, which reflect sunlight and so alter the radiative balance. As a consequence, SO2 has positive impacts on climate