净化废水是一项重要的环保任务，目的是将废水中的有害物质去除，使其达到可排放的标准。废水中的有害物质包括重金属、有机化合物、细菌等，这些物质对环境和人类健康都有很大的危害。

废水净化的方法有很多种，包括生物法、化学法、物理法等。生物法是利用微生物将废水中的有机物降解成无害物质，化学法是利用化学反应将废水中的有害物质转化为无害物质，物理法是通过过滤、沉淀、蒸馏等物理过程将废水中的有害物质去除。

废水净化的过程需要专业的设备和技术支持，同时也需要严格的监管和管理。只有在全社会的共同努力下，才能够实现废水净化的目标，保护环境，维护人类健康。

English Translation:

Purifying wastewater is an important environmental task, which aims to remove harmful substances from wastewater and make it meet the standards for discharge. Harmful substances in wastewater include heavy metals, organic compounds, bacteria, etc. These substances have significant hazards to the environment and human health.

There are many methods for wastewater treatment, including biological, chemical, and physical methods. The biological method uses microorganisms to degrade organic matter in wastewater into harmless substances, the chemical method uses chemical reactions to transform harmful substances in wastewater into harmless substances, and the physical method removes harmful substances in wastewater through filtration, precipitation, distillation and other physical processes.

The process of wastewater treatment requires specialized equipment and technical support, as well as strict supervision and management. Only with the joint efforts of the whole society can we achieve the goal of wastewater treatment, protect the environment, and maintain human health.