fouling of heat exchangers

例句：

1. 1.The sewage system is a major sourceof pollution in the city.
   这个城市的主要污染源是污水系统。
2. 2. Thefactory has been foulingthe river with its wastewater.
   这个工厂的废水一直在污染这条河。
3. 3. The oil spill fouled up thefishing industry for months.
   这次石油泄漏影响了渔业几个月。