Search results
Results from the WOW.Com Content Network
Keeping the pH in a suitable range (5.0-9.0 for freshwater systems) is crucial to maintain the health of both the fish and biofilter. pH is typically controlled by the addition of alkalinity in the form of lime (CaCO 3) or sodium hydroxide (NaOH). A low pH will lead to high levels of dissolved carbon dioxide (CO 2), which can prove toxic to fish.
Soda lime canister used in anaesthetic machines to act as a carbon dioxide scrubber. Soda lime, a mixture of sodium hydroxide (NaOH) and calcium oxide (CaO), is used in granular form within recirculating breathing environments like general anesthesia and its breathing circuit, submarines, rebreathers, and hyperbaric chambers and underwater habitats.
Focused research on oil pollution toxicity to fish began in earnest in 1989, after the Exxon Valdez tanker struck a reef in Prince William Sound, Alaska and spilled approximately 11 million gallons of crude oil into the surrounding water. [6] At the time, the Exxon Valdez oil spill was the largest in the history of the United States. [6]
A purple sea urchin being tested for pollution using a whole effluent toxicity method.. Aquatic toxicology is the study of the effects of manufactured chemicals and other anthropogenic and natural materials and activities on aquatic organisms at various levels of organization, from subcellular through individual organisms to communities and ecosystems. [1]
Oil is "acutely lethal" to fish - that is, it kills fish quickly, at a concentration of 4000 parts per million [25] (0.4%). The toxicity of petroleum related products threaten human health. Many compounds found in oil are highly toxic and can cause cancer (carcinogenic) as well as other diseases. [23]
Calcined gypsum is an alternative material in industrial plasters and mortars. Cement, cement kiln dust, fly ash, and lime kiln dust are potential substitutes for some construction uses of lime. Magnesium hydroxide is a substitute for lime in pH control, and magnesium oxide is a substitute for dolomitic lime as a flux in steelmaking. [28]
The BLM is used to predict the lethal accumulation (LA50) of metals on the gill surface that results in mortality of 50% of the exposed individuals. [3] [10] Accumulation of metals on the gill surface is dependent on the specific area's water quality as the metal's bioavailability for binding with the ligand will be determined by what's in the water that the metal is likely to complex to other ...
Highly Toxic: a gas that has a LC 50 in air of 200 ppm or less. [2] NFPA 704: Materials that, under emergency conditions, can cause serious or permanent injury are given a Health Hazard rating of 3. Their acute inhalation toxicity corresponds to those vapors or gases having LC 50 values greater than 1,000 ppm but less than or equal to 3,000 ppm ...