It was a quantitative target for describing of self-purification capacity of water environment of area.
它是描述一个地区水环境自净能力大小的定量指标。
2
It could have been avoided coke, bonded and blockage occurred, but also to facilitate cleaning and self-purification.
它可以避免结焦，粘结和堵塞等现象发生，也便于清洗和自净。
3
Many minerals in nature have the self-purification capacity to hold and stabilize deleterious contaminant, which can be used to deal with heavy metal contaminants.