a) Assume that algae need carbon, nitrogen and phosphorous in the ratios 106:16:1. What is the limiting nutrient in a lake that contains the following concentrations: total C = 16mg/L, total N = 1mg/L and total P = 0.15 mg/L? b) How can the use of detergents impact the nutrient availability in the lakes? Why is phosphate used in detergents? (3) c) If it is known that half the phosphorus in the lake (in part a) originates from the use of phosphate detergents, will banning phosphate builders slowdown eutrophication? (2)

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