课题2-水的净化VIP专享VIP免费

九年级化学备课组2015.10.课件制作:小平閤海水河水湖水井水自然界的水纯水是无色、无味、清澈透明的。而自然界中的河水、湖水、井水、海水等天然水里由于含有许多可溶性和不溶性杂质，因此常呈浑浊（如图所示）。你知道水里有哪些杂质吗？微生物和细菌可溶性的杂质这是府河里的水这是府河里的水不溶性的杂质水体污染示意图工业三废农药化肥3．自来水厂净化水的过程：一、纯水与自然界的水原水→静置→絮凝沉淀→反应沉淀→过滤→吸附→消毒→生活用水。加明矾除不溶性杂质除可溶性杂质１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１自来水厂净水过程图除去不溶性杂质除去可溶性杂质，吸附颜色和异味杀菌消毒吸附水中悬浮的杂质沉降杂质沉降杂质1．静置沉淀：利用物质的重力作用，１１１１１１１１１１１１１１１１１１１１简单易行，净化程度低。二、水的净化方法2１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１吸附剂沉淀法：吸附悬浮物浑水变澄清(1).过滤可以分离与的混合物固体液体(2).过滤操作需要哪些仪器？3、过滤法铁架台滤纸漏斗烧杯玻璃棒二、水的净化方法(3).过滤的操作要点：一贴：滤纸要紧贴漏斗的内壁。二低：滤纸的边缘要低于漏斗的边缘；滤液的液面要低于滤纸的边缘。三靠：玻棒下端要靠三层滤纸的一边；烧杯口要紧靠引流的玻璃棒;漏斗的下端要紧靠烧杯内壁。⑷玻璃棒的作用：引流《活动与探究》过滤注意操作要点１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１想一想：1、过滤后，滤液仍然浑浊可能的原因有那些？应该再过滤一次，直到滤液澄清为止。(1)滤纸破损(2)液面高于滤纸边缘(3)仪器不干净等2、河水过滤后，滤液可以喝吗？不能，因为过滤不能去除可溶的杂质及微生物１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１二、水的净化方法活性炭吸附池常用吸附剂：活性炭.吸附剂的作用是：除去可溶性杂质，如颜色及异味。问题：现在得到的水可以放心饮用了吗？5.杀菌消毒加入消毒剂：氯气、二氧化氯、漂白粉1、通常用于自来水的消毒。氯气有杀菌力强、价格低等优点，一直是当今世界上使用最多，且应用最广泛的。2、氯气能溶于水，常温下在水中与水反应生成强氧化剂次氯酸。次氯酸能杀死细菌。同样，把漂白粉加入水中也能生成次氯酸。吸附沉淀过滤吸附消毒(明矾除去小颗粒悬浮物)(静置沉淀除去大颗粒悬浮物)除去不溶性不溶性固体杂质(活性炭主要吸附色素和异味)(过滤除去极小颗粒悬浮物)除去溶于溶于水水的杂质除去微生物和细菌(加入氯气，杀死细菌和病毒)静置沉淀１１１１１１１１净化水的过程中哪些步骤发生了化学变化？2、消毒剂溶于水生成了次氯酸,次氯酸有消毒杀菌的功效，故杀菌消毒的过程中发生了化学变化。1、加入絮凝剂（明矾）后，明矾溶于水，生成胶状物，属于化学变化。家庭小实验１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１鲁滨逊利用自制的过滤器过滤泥水，这样制取的水可以喝吗？因为水中还有可溶杂质和微生物，会对人体造成危害，需煮沸后饮用。6１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１7１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１二、水的净化方法１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１１二、水的净化方法三、硬水和软水1．硬水：含有较多可溶性钙、镁化合...