tailieunhanh - Environmental Pollution Control Microbiology - Chapter 8

Nước là điều cần thiết cho tất cả đời sống sinh học. Cả hai thực vật và động vật sử dụng nước để thực hiện các chất dinh dưỡng đến các tế bào của họ và để thực hiện sản phẩm chất thải, cho phép họ tiếp tục tồn tại. Từ chu kỳ thủy văn, chúng tôi đã học được rằng, cũng như dòng chảy trên bề mặt đất trên cuộc hành trình của mình đến các đại dương, nó chọn khoáng chất hòa tan từ đất, cũng như các hạt lơ lửng. Những chất gây ô nhiễm này, chọn. | Chapter 8 WATER MICROBIOLOGY Water is essential for all biological life. Both plants and animals use water to carry nutrients to their cells and to carry waste products away permitting them to continue to exist. From the hydrological cycle we learned that as water flows over land surfaces on its journey to the oceans it picks up soluble minerals from the soil as well as suspended particles. These contaminants picked up by the flowing water provide a good environment for the growth of some microorganisms. Ultimately the water reaches the ocean. The suspended contaminants slow their velocity and settle out. The soluble contaminants mix with the ocean waters where the continuous evaporation of water from the ocean by the sun concentrates the soluble contaminants to a much greater level over time. The microorganisms in nature have adapted to the highly saline environment in the oceans creating similar groups as in fresh water. The meeting of fresh waters and saline ocean waters creates a saline gradient that allows the microorganisms to adapt from one environment to the other environment. Contaminant gradients are essential for microbial adaptations from safe environments to harsh environments. RIVER WATER MICROBIOLOGY The microbiology in river water starts with the organisms and nutrients picked up as the water flows over the land surface. River water starts high in the mountains. The mountains have sustained centuries of precipitation with small changes. The high altitude and low temperatures in the mountains prevent biological growths Copyright 2004 by Marcel Dekker Inc. All Rights Reserved. except for microorganisms sheltered from the harsh environment. Cyanobacteria which have the ability to fix gaseous nitrogen from the atmosphere grow very slowly producing organic matter from sunlight and limited nutrients. The Cyanobacteria stimulate the growth of green algae and together they stimulate fungi growth creating lichens that form on the rocks. The lichens and .