Ponds, algae

Nurdogan, Y., Oswald, W.J., 1996. Tube settUng rate of high-rate pond algae. Water Science and Technology 33, 229—241. 

Yields of algae grown in outdoor pond cultures (Table 1) are on the order of 15-40 g/(m -d) (24 short tons pet acre pet year). Higher yields can be obtained under artificial illumination, but growth of algae under these conditions is not economically feasible. 

Granular) control of algae and bacteria in ponds—5—10 mg/L residual chlorine for 12—24 h ... 

Stabilization Ponds. Stabilization ponds have a water depth of 1—2 m and oxygen is suppHed by surface entrainment or by algae. The BOD loading must be low and the detention time is 5—25 days (218). 

Facultative pond The most common type of pond in current use. The upper portion (supernatant) is aerobic, while the bottom layer is anaerobic. Algae supply most of the oxygen to the supernatant. 

In 1968, reports from Sweden, subsequently confirmed in other industrial countries, noted that shallow lakes with low concentrations of divalent cations were becoming more acidic with consequent decreases in aquatic plants and animals. In severely affected lakes and ponds, only acidophilic algae survived. Increased acidity and the runoff of solubilized aluminum and other metal ions from surrounding watersheds are now known to be primarily responsible for formation of these almost sterile bodies of water. 

Algal blooms in fresh water ponds occasionally poison livestock and waterfowl. Axenic cultures of Anabaena flos-aquae NRC 44-1 were shown to produce the toxic principle (5) which can be present in the algae and in the water of mature cultures (6). The discovery of the toxin was fortuitous in the sense that AChR agonists do not have a (known) constructive function in the algae evolution of the synthetic pathway was likely a by-product of metabolic pathways in the algae. The compound became evident only through its toxic effects on other organisms. 

In ponds where there are viable fish and plant populations, algae are seldom seen. Explain why this might happen. 

Green alga, Cladophora sp. Missouri, tailings pond 11,300 DW 5... 

Filamentous algae (Chara sp., Enteromorpha sp.) 50-100 Lethal in 30 days in outdoor ponds decay was responsible for depression of dissolved oxygen and later fish deaths 2... 

AQUATIC PLANTS Algae, decomposing Hanford, Washington, 1973 plutonium processing pond 241 Am 9472 DW 15... 

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