On October 5, the Ministry of Natural Resources gave an update on one of the country’s quietest industries. China can now turn more than three million tonnes of sea water into fresh water every single day. The exact number is 3.077 million tonnes a day, and more plants are on the way.
Sea water desalination means taking the salt out of the ocean so that the water can be used by people. There are two main ways to do it. One is to heat the water until it turns into steam, leaving the salt behind. The other pushes the water through a special membrane that holds the salt back. Both methods need a lot of energy, which is why the cost has always been the key problem.
The demand is easy to understand. Many coastal cities are short of fresh water, and rivers cannot always supply enough for farms, factories and families. When a dry year comes, the shortage becomes serious. Building a desalination plant gives a city a source of water that never depends on the weather.
In July, three government departments published an action plan for the industry. The goal is to reach 4.5 million tonnes a day by 2030, an increase of more than 1.5 million tonnes. The plan also calls for better technology and lower energy use, because old plants still burn too much power.
There are still questions to answer. The salty waste water left behind must be dealt with carefully, and the cost of each tonne is higher than water taken from a river. Yet for a country with a long coastline and a growing population, the sea may become an important part of the answer.
Words to know:
- desalination (n. 海水淡化，脱盐)
- steam (n. 蒸汽，水汽)
- membrane (n. 膜，薄膜)
- shortage (n. 短缺，不足)
- supply (v./n. 供给，供应)
- coastline (n. 海岸线)
- energy (n. 能源，能量)
- population (n. 人口)
长难句拆解 · which 引导非限制性定语从句 + 现在分词作后置定语
原文：Both methods need a lot of energy, which is why the cost has always been the key problem.
拆解：主干是 Both methods need a lot of energy（两种方法都需要大量能源）。前半句是结构简单的主谓宾。逗号后 which 引导非限制性定语从句，which 指代前面整句所表达的事实，即「两种方法都耗能」；is why 表示「这就是……的原因」，后面接表语从句 the cost has always been the key problem。注意此处 which 不能换成 that，非限制性定语从句只能用 which。
直译：两种方法都需要大量能源，这就是为什么成本一直是核心问题。
同义替换 · 雅思阅读利器
雅思阅读最爱把原文的词换成另一个说法来出题，认出这些替换，定位就能快一半。
- turn sea water into fresh water → change salt water into drinking water（fresh water ＝ 淡水）
- taking the salt out of the ocean → removing salt from the sea（take … out of ＝ remove … from）
- leaving the salt behind → with the salt left over（leave behind ＝ 留下、剩下）
- holds the salt back → keeps the salt out（hold back ＝ 挡住）
- are short of fresh water → do not have enough fresh water（be short of ＝ 缺乏）
- a source of water that never depends on the weather → a supply that is not affected by rain（depend on ＝ be affected by）
- calls for better technology → asks for / requires better technology（call for ＝ 要求）
阅读自测 · 3 题
- T / F / NG：按照行动计划，到 2030 年中国海水淡化总规模将达到每天 450 万吨。（判断正误并说明依据）
- 简答：中国目前的海水淡化总规模是多少吨每天？
- 选词填空：The salty waste water left behind must be ____ carefully.（供选：dealt with / dealt in / dealt out）
参考答案与解析
- TRUE。原文说 The goal is to reach 4.5 million tonnes a day by 2030。题目把 4.5 million tonnes 换成 450 万吨，说法一致。注意干扰套路：若题目写成「到 2030 年新增 450 万吨」就属于偷换概念，因为 450 万吨是总量，新增部分只有 150 万吨以上。
- 每天 307.7 万吨。原文给出 The exact number is 3.077 million tonnes a day。不要误答成 2030 年的目标 450 万吨，那是未来值。
- dealt with。deal with 意为「处理、应对」，此处为被动语态 must be dealt with，指废水必须被妥善处理。deal in 意为「经营、买卖」，deal out 意为「分发」，都不能与 waste water 搭配。
中文译文
10 月 5 日，自然资源部介绍了国内最不引人注意的行业之一的近况。如今，中国每天能把 300 多万吨海水变成淡水。精确数字是每天 307.7 万吨，而且还有更多工程正在建设中。
海水淡化，就是把盐从海水中去掉，使水可以供人使用。主要方法有两种。一种是加热海水，让它变成蒸汽，把盐留在后面。另一种是让水通过一层特殊的膜，把盐挡在外面。两种方法都需要大量能源，因此成本一直是核心难题。
需求不难理解。许多沿海城市缺少淡水，河流也未必总能满足农田、工厂和家庭的用水。一旦遇上干旱年份，缺口就变得严重。建一座海水淡化厂，等于给城市找到了一个不靠天气的水源。
今年 7 月，三个政府部门联合发布了该产业的一份行动方案。目标是到 2030 年达到每天 450 万吨，即新增 150 万吨以上。方案还要求提升技术、降低能耗，因为老旧工厂仍然耗电过多。
仍有一些问题待解。淡化后排出的高盐废水必须谨慎处理，而且每吨水的成本高于从河里取水。不过，对于一个海岸线漫长、人口持续增长的国家来说，海洋或许会成为答案中重要的一部分。