Construction managers, also called general contractors or project managers, typically do the following: 1  Prepare and negotiate cost estimates, budgets, and work timetables. 2  Select appropriate construction methods and strategies. 3  Interpret and explain contracts and technical information to workers and other professionals.
Denitrification is the process that converts nitrate to nitrogen gas, thus removing bioavailable nitrogen and returning it to the atmosphere. Dinitrogen gas (N2) is the ultimate end product of denitrification, but other intermediate gaseous forms of nitrogen exist (Figure 7).
Nitrogen dioxide is not usually released directly into the air. Nitrogen dioxide forms when nitrogen oxide (NO) and other nitrogen oxides (NOx) react with other chemicals in the air to form nitrogen dioxide. The main source of nitrogen dioxide resulting from human activities is the combustion of fossil fuels (coal, gas and oil) especially fuel used in cars. It is also produced from making nitric acid, welding and using explosives, refining of petrol and metals, commercial manufacturing, and food manufacturing.