For each child, the researchers measured the concentration of manganese in tap water from their home, as well as iron, copper, lead, zinc, arsenic, magnesium and calcium.
对于每一个孩子，研究者检测了他们家里自来水中锰、铁、铜、铅、锌、砷、镁和钙的含量。
2
The arsenic in water samples was first enriched by co-precipitation with iron hydroxide.
用氢氧化铁共沉淀水中痕量砷，沉淀用离心机分离和富集。
3
The transparent iron oxide yellow was prepared by using the yellow precipitates after separating arsenic and iron from the wastewater.