摘 要:现行高中教材中的化学实验存在许多污染问题,不利于培养学生的环保意识,也对师生的身体健康造成危害。在人们的环境保护观念日益增强的今天,实现化学实验绿色化变得非常紧迫。
要实现中学化学实验绿色化,必须解决两个问题:一是培养学生绿色意识,二是改革高中化学实验,消除现行实验的污染。针对这两个问题,论文总结了培养学生绿色实验意识的重要性及其培养途径和方法,在反复试验的基础上,对教材中每个实验进行逐个研究,根据绿色化学原理提出了一套绿色实验设计方案,自行设计了一些实验装置,对现行教材中的实验装置进行了改进,解决了中学化学实验中的污染问题。
现行实验中产生的的有毒气体,只能用通风设备排入空气,设备昂贵而污染并不能消除。我们改进和自行设计的实验装置(毒气罩和组合试管等),能将有毒气体生成无毒物质,避免污染大气。这些绿色实验设计方案已在中学化学实验中使用,为中学化学教师提供了有益参考。通过对绿色实验设计方案的不断改进、优化,使实验装置更加安全可靠,切实可行。绿色实验设计方案的实施,有利于改善中学化学实验教学环境,增进学生的绿色化学和环境保护意识,提高全民的素质,实现社会的可持续发展。
关键词:高中化学实验,绿色化学实验,实验方案,实验探索
Abstract :Currently, lots of pollution problems exist in the experiments involved in senior middle school chemical courses, which give bad influences on cultivating students’ environmental protecting spirit and cause damage to the health of both teachers and students. Nowadays, environment protection has been deeply rooted in people’s conception and received intensive attention, thus it is imperative for us to construct environment amicable methods for chemical experiments.
In order to make the chemical experiments environment amicable, two problems need to be solved at first, one is cultivating the students with environmental protecting spirit and another is reforming the current chemical experiments of senior middle school to annihilate the pollutions caused by these experiments. This thesis summarized the significances and the methods of cultivating students with environmental protecting spirit, investigated chemical experiments of the text book based on the repeated experiments and proposed a series of environment amicable schemes according to the green-chemistry principles, in addition, some experimental devices were originally designed to improve the current experimental methods and finally eliminate the experimental pollutions.
Poison gases emitted from the current experiments can only be ventilated into atmosphere via laboratory venting equipments which cost a lot and can not effectively eliminate the pollutions. We improved and originally designed experimental devices such as poison mask, assembled tubes and so on which can convert the poison gases into harmless therefore avoid the atmosphere contamination. These methods have already been applied in chemical experiments of the senior middle school providing teachers with beneficial examples. By means of the constantly improvement and optimization of the experimental methods, the experimental devices could be more safe and manageable. The employment of these methods can ameliorate the experiment conditions of the senior middle school, enhance the environmental protecting spirit of the students, improve the overall quality of the people and achieve the sustainable development of the society.
Key words: chemical experiments of senior middle school, environment amicable chemical experiment, experiment methods, experiment investigation
1 引 言
1.1绿色化学与化学实验绿色化产生的背景
环境保护问题是人类面临的三大问题(人口、能源、环境)之一。地球只有一个,地球环境的好坏直接关系到人类能不能生存下去的问题。因此,实施可持续发展战略、重视环境保护已成为世界各国的焦点,保护人类的生存环境已成为人们的共同呼声。化学污染对环境、人类健康、社会发展的危害,越来越受到社会的普遍关注。人们逐渐认识到,化学在造就更好的物质,创造更美好生活的同时,也为人类带来了严重的污染。自然界中从未发现过的人工合成化合物正在以高速度增加,估计已有96000种化合物质进入人类环境,其中有许多是有毒化学物质,这些有毒物质通过各种可能的途径危害着人类的健康,而且,化学品的生产、使用与处理,给环境造成越来越严重的污染。起初人们试图通过减少废气、废水和固体废弃物的排放量来解决污染问题,而后又通过法规来对废弃物进行管理。废物控制和处理,环保监测、达标,事故责任赔偿等费用使加工费用大幅度上升。因此,从环保、经济和社会的要求看,化学工业不能再使用和生产有毒、有害物质。在严峻的现实面前,人们开始大力研究与开发“从源头上减少和消除污染”的化学途径和方法。1990年美国颁布了污染防治法案,将污染防止确立为美国的国策,在该法案中第一次出现了“绿色化学”一词,其定义为:采用最少的资源和能源消耗,产生最小的排放的工艺过程。