What Happens When You Flush

What happens when you flush? Written by Lisa Meltzer Focus Question Where does sewage go and how is it treated?

冲水之后会发生什么？ 莉萨·梅尔策 著 思考问题：污水会去哪里，又是怎么处理的呢？

Introduction. Swoosh! You hear this sound every time you flush a toilet. But did you ever stop to wonder where everything that you flush down winds up? Getting rid of waste takes more than just pushing the handle on a toilet. In fact, it is often a complex process. That process can stretch over, or under, many miles in your city or town.

前言 哗啦！ 每次你冲马桶的时候都会听到这个声音 可你有没有停下来想过，你冲下去的东西最后都去了哪里？ 处理废弃物可不只是按下马桶冲水把手那么简单 事实上，这通常是一个很复杂的过程 这个过程会延伸到城镇的地表或地下，绵延好几英里

Where does waste come from? Where does it go? Human waste is called sewage. In most homes, it is created by using the toilet, taking showers, doing the dishes, washing clothes, or doing anything that makes water dirty. The average American turns about 100 gallons, 380 liters of water into sewage each day. Factories and restaurants create sewage too. In time, all this sewage could reach our drinking water, making it unsafe.

垃圾从哪里来？ 它又去哪里？ 人类产生的废弃物叫做污水 大多数家庭里，用马桶、洗澡、洗碗、洗衣服，或是任何会弄脏水的活动都会产生污水 美国人平均每天会产生大约100加仑，也就是380升的污水 工厂和餐馆也会产生污水 久而久之，这些污水可能会渗入饮用水，让水变得不再安全

More than 2 billion people around the globe have no flush toilets or sewerage systems. Most of their waste either piles up on the land or runs into lakes and rivers. Millions of people die each year from diseases that come from sewage. Sewage treatment experts are working hard to solve this problem, but it is a huge task. Fortunately, the sewer pipes in our homes don't just empty into our drinking water. Instead, in many cities and towns, all of this dirty water ends up in the local sewerage system. Small sewer pipes join up to form bigger and bigger pipes. Some are so big that humans can walk through them.

全球有超过20亿人没有抽水马桶，也没有污水处理系统 他们产生的大部分废弃物要么堆积在陆地上，要么流进湖泊和河流 每年都有数百万人死于污水引发的疾病 污水处理专家一直在努力解决这个问题，但这是一项非常艰巨的任务 幸运的是，我们家里的污水管不会直接把污水排进饮用水中 相反，在很多城镇，所有污水最终都会汇入当地的污水处理系统 小型污水管汇在一起，变成越来越粗的管道 有些管道粗得足够人在里面行走

Inside the treatment plant. The sewage moves through this large group of pipes to a sewage treatment plant. Here, the water is cleaned. Organisms that can cause disease and other pollutants are removed. Not all sewage treatment systems are alike. One common type cleans sewage in the following way. Step 1. A big screen – think of a giant kitchen strainer – removes large items such as rocks, sticks, and garbage. That way, they don't jam the treatment plant's machines.

污水处理厂内部 污水顺着这一大片管道流到污水处理厂 在这里，污水会得到净化 致病微生物和其他污染物都会被清除 并不是所有污水处理系统都一模一样 有一种常见的处理工艺，步骤如下 第一步 一块大格栅——你可以把它想象成超大号的厨房滤勺——会过滤掉石头、树枝、垃圾这类大物件 这样一来，这些东西就不会卡住处理厂的机器了

Step 2. What is left over after this process is called sludge, which is thick, dirty water. The treatment plant pumps air into the sludge, which helps bacteria grow. These helpful bacteria eat the sludge to break it down. Step 3. Next, the broken down sludge is sent to another machine. Here, all of the solid waste settles to the bottom. The water at the top is sent to a filter that cleans it further.

第二步 过滤后剩下的物质叫做污泥，是又稠又脏的混合物 处理厂会往污泥里泵入空气，帮助细菌生长 这些有益细菌会吃掉污泥，把污泥分解掉 第三步 接下来，分解后的污泥会被送到另一台机器中 在这里，所有固体废物会沉淀到底部 上层的水会被送到过滤器中，进行进一步净化