Cattle manure and calcium superphosphate were main polluting material.
牛粪、过钙是基质中主要镉污染物质。
2
We make superphosphate by reacting rock phosphate with sulphuric acid.
我们使磷酸盐岩同硫酸发生化学反应制造过磷酸钙。
3
It is practically insoluble in water and only very slowly soluble in diluted acids, so it is largely converted for fertilizing purposes into superphosphate.