在雅思写作Task 1中，流程图（Flow Chart）是常见题型之一，要求考生准确描述某个过程的步骤，污水处理（Wastewater Treatment）是高频话题，掌握其写作技巧对考生至关重要，本文将结合最新数据，提供一篇高质量的流程图范文，并解析写作技巧，帮助考生高效备考。
雅思流程图写作核心技巧
明确流程阶段划分
污水处理通常分为几个关键步骤，考生需清晰划分：
- 初级处理（Primary Treatment）：物理过滤
- 二级处理（Secondary Treatment）：生物分解
- 三级处理（Tertiary Treatment）：化学净化
- 排放或再利用（Discharge/Reuse）
使用恰当的衔接词
流程图强调顺序，需灵活运用以下连接词：
- 起始阶段：Initially, First of all
- 中间步骤：Subsequently, After that
- 最终阶段：Finally, Ultimately
避免重复句式
被动语态在流程图中很常见，但需变换表达方式，
- The wastewater is filtered → Filtration removes large solids
- Chemicals are added → The process involves chemical treatment
最新污水处理数据与趋势
根据世界银行2023年报告，全球污水处理效率存在显著差异，以下是部分国家污水处理率对比：
| 国家 | 污水处理率（2023） | 主要处理技术 |
|---|---|---|
| 新加坡 | 100% | 高级膜过滤 |
| 德国 | 98% | 生物+化学联合处理 |
| 中国 | 85% | 活性污泥法 |
| 印度 | 35% | 初级沉淀 |
（数据来源：World Bank, Wastewater Management Report 2023）
国际水协会（IWA）指出，2024年全球约80%的废水未经充分处理直接排放，凸显污水处理技术推广的紧迫性。
雅思流程图范文：污水处理
The diagram illustrates the process of wastewater treatment in a modern plant.
Initially, wastewater enters the treatment facility through underground pipes. The first stage, primary treatment, involves passing the water through a bar screen to remove large debris such as plastic and rocks. Subsequently, the water flows into a sedimentation tank, where gravity separates suspended solids from the liquid.
In the secondary treatment phase, the water is transferred to an aeration tank. Here, microorganisms break down organic matter, a process enhanced by pumping air into the tank. After this biological treatment, the water moves to another sedimentation tank to remove the remaining sludge.
The final stage, tertiary treatment, employs chemical disinfectants like chlorine or UV light to eliminate harmful pathogens. According to the UN Environment Programme (2023), advanced plants may also use reverse osmosis for additional purification.
Ultimately, the treated water is either discharged into rivers or recycled for agricultural/industrial use. The sludge from sedimentation tanks is often processed into fertilizer or incinerated.
如何优化流程图写作得分
-
数据引用增强可信度
"As reported by the European Environment Agency (2024), over 90% of EU wastewater plants now include nutrient removal steps."
-
比较不同技术差异
- 传统方法：活性污泥法（成本低但效率中等）
- 新兴技术：厌氧氨氧化（节能30%，但投资高）
-
使用学术化表达
避免口语化词汇，- "gets clean" → "undergoes purification"
- "dirty stuff" → "contaminants"
个人观点
雅思流程图写作的关键在于逻辑清晰与细节精准，考生应多研究真实案例，例如新加坡的NEWater技术或荷兰的循环水管理系统，这些实例既能丰富内容，又能体现对全球议题的关注，定期查阅联合国水务报告或OECD环境数据，确保引用信息的时效性和权威性，这对满足E-A-T（专业知识、权威性、可信度）评分标准至关重要。
