Nitrogen is a vital nutrient for crops, but soils rarely produce enough of it to sustain the relentless farming needed to feed a world population that has more than doubled in the past 50 years. For ...

Research Journal of the Water Pollution Control Federation, Vol. 62, No. 5 (Jul. - Aug., 1990), pp. 692-696 (5 pages) Duckweed is one of the floating aquatic macrophytes with a preference for ammonia ...

Treating wastewater properly is necessary to ensure good water quality. The EU has introduced new rules to better protect people and the environment. On this page A major cause of water pollution Main ...

Over the past few decades, the explosive growth of megacities has captured the attention of researchers, economists, and urban developers, while the world’s small towns -- and the particular ...