水的净化(Water Purification)
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取水口■"W 1声附泄蓿水池击打用户而【1水的净化方法一、自来水厂净水过程1.水的净化要解决的三个主要问题:① 除去不溶性杂质;②除去可溶性杂质;③除去有毒物和有害细菌。
2.流程:取水一沉淀一过滤一吸附一消毒一配水 注意: ① 该过程中只有"消毒”是化学变化,"沉淀”、"过滤”、“吸附”均为物理变化。
② 有些不溶性杂质很细小,仅靠自身重力很难沉降,加入絮凝剂可以促进不溶物沉淀。
明矶[KAI(SO 4)2・12H 2O ]就是一种常见的絮凝剂。
③ 沉淀、过滤、吸附也是化学实验中常用的分离混合物的方法。
④ 经沉淀、过滤、吸附处理后的水并不是纯水,仍含可溶性杂质。
二过滤用于分离固液混合物的方法应沉沉淀杂质自来水厂净水过程示育图吸附水中悬浮的杂质加絮凝剂除去可蓿性杂质,颜色、异味一、■1杀死残存' 的细菌 J除去不招性朵质投药消垂操作要点:一贴、二低、三靠说明:一贴:滤纸紧贴漏斗内壁;二低:滤纸边缘低于漏斗边缘,液面低于滤纸边缘;三靠:倾倒滤液的烧杯尖嘴紧靠玻璃棒(目的:防止液体溅出),玻璃棒紧靠三层滤纸处(目的:防止戳破滤纸),漏斗下端管口紧靠烧杯内壁(目的:防止滤液溅出)。
注意:过滤只能除去不溶性杂质,无法除去可溶性杂质。
三、吸附活性炭具有疏松多孔的结构,在净水过程中起吸附作用,该过程为物理变化。
用具有吸附作用的固体过滤,不仅可以滤去不溶性杂质,还可以吸附一些可溶性杂质,除去颜色和气味。
这是市场上出售的使用活性炭的净水器的净水原理。
制取蒸馏水的简易装置四、蒸馏用于分离液体混合物的方法原理:利用液体混合物中各组分沸点不同,使低沸点组分先蒸发,再冷凝,以分离整个组分。
蒸馏得到的水称为蒸馏水,是净化程度较高的水。
实验室常用的蒸馏装置—制度计爪蕪气蒸懦装置KiElfl 水口人水口活性炭净水器示意图简易净水器示意图河水 注意:水的净化方法通常包括沉淀、过滤、吸附和蒸馏。
【关键字】大学英语作文水的净化(Water Purification)水的净化(water purification)the provision of safe water necessitates one of the rnajor expenditures of manpower and revenue in our modern cities. the purification of water is basically a two-step or three-step process carried out under the strict supervision of public health scientists and engineers. as the first step, natural water from the least contaminated source is allowed to stand in large reservoirs, where most of the mud, clay, and silt settle out; this is called "sedimentation". often in water with high mud content, lime and aluminum sulfate are added to the water in the settling reservoirs. these chemicals react in the water to form aluminum hydroxide, which settles slowly andcarries much of the suspended material, including most of carries much of the suspended material, including most of the bacteria, to the bottom of the reservoirs. as the second step, the water is filtered through beds of sand and grovel, which remove other impurities and chemicals in it. during or after filtration, chemicals are ordinarily added to the water to kill any remaining harmful bacteria. chlorine is one of the most common chemicals used for this purpose. a third step taken by some rmnicipalities is adding to the water other beneficial chemicals such as fluoride to make tooth enamel hard, and soda ash to make the water itself soft. the water purification process,carried out with little variation from one large city to another, is perhaps the biggest factor in the prevention of major outbreaks of disease in this country.文档从互联网中收集,已重新整理排版,word版本支持修改!。
水的净化(Water Purification)
水的净化(Water Purification)水的净化(Water Purification) 水的净化(water purification)
the provision of safe water necessitates one of the rnajor expenditures of manpower and revenue in our modern cities. the purification of water is basically a two-step or three-step process carried out under the strict supervision of public health scientists and engineers. as the first step, natural water from the least contaminated source is allowed to stand in large reservoirs, where most of the mud, clay, and silt settle out; this is called sedimentation . often in water with high mud content, lime and aluminum sulfate are added to the water in the settling reservoirs. these chemicals react in the water to form aluminum hydroxide, which settles slowly and carries much of the suspended material, including most of carries much of the suspended material, including most of the bacteria, to the bottom of the reservoirs. as the second step, the water is filtered through beds of sand and grovel, which remove other impurities and chemicals in it. during or after filtration, chemicals are ordinarily added to the water to kill
any remaining harmful bacteria. chlorine is one of the most common chemicals used for this purpose. a third step taken by some rmnicipalities is adding to the water other beneficial chemicals such as fluoride to make tooth enamel hard, and soda ash to make the water itself soft. the water purification process, carried out with little variation from one large city to another, is perhaps the biggest factor in the prevention of major outbreaks of disease in this country.。