Читать книгу Sustainable Water Purification - M. R. Islam - Страница 16

Natural additives have been used for the longest time, dating back to the regime of the Pharaohs of Egypt and the Hans of China (Gove, 1965). However, the renaissance in Europe has given rise to industrial revolution that became the pivotal point for the emergence of numerous artificial chemicals. Today, thousands of artificial chemicals are being used in everyday products, ranging from health care products to transportation vehicles. With renewed awareness of the environmental consequences and more in-depth knowledge of science, we are discovering that such ubiquitous use of artificial chemicals is not sustainable (Khan and Islam, 2016). If the pathways of various artificial chemicals are investigated, it becomes clear that such chemicals cannot be assimilated in nature, making an irreparable footprint that can be the source of many other ecological imbalances (Chhetri and Islam, 2008). Most persistent and bioaccumulative chemicals eventually find their way into our bodies via the food chain. Chemical industries mass produce artificial additives and, therefore, gain the advantage due to the economy of scale, in line with modernization since the industrial revolution.

Federal regulators have determined that about 4,000 chemicals used for decades in Canada pose enough of a threat to human health or the environment that they need to be subjected to safety assessments (The Globe and Mail, 2006). These artificial additives are either synthetic themselves or derived through an extraction process that uses synthetic products. Even when the source is natural, it may have been contaminated through artificial agents, such as chemical fertilizer, pesticide, etc. These artificial chemicals have a number of hidden adverse side effects. Furthermore, once artificial additives are disposed into the environment, they remain in nature for a very long time. These synthetic products never degrade biologically; they are either pulverized (hence become invisible) or oxidized to produce toxins (Khan and Islam, 2016). On the other hand, natural additives are naturally occurring substances that are considered valuable in their natural form. Most of the natural materials are readily biodegradable, so they have zero waste and they have no long term negative impact. Natural materials are inherently superior to synthetic materials with regard to efficacy and safety in matters related to human health. Any attempt to improve current engineering practices should investigate the possibility of replacing artificial additives with natural ones that are environment friendly and truly sustainable (Khan and Islam, 2007).