Water resources is an indispensable resource keep human and other organism survival. Sustainable development of water resources (Clean Water and Sanitation) is closely related to the continued development of ecological environment. Many countries still have many water resources problems such as insufficient water resources and insufficient fund for treating wastewater. These unsolved water problem affect the social-economic development of the region and adversely affect the ecological environment of the region. Water-resource is limited we can’t generate water from nowhere, wastewater re-circulation (reuse) is significant. So, what is wastewater? Wastewater refers to the water that is after been used on daily life, commercial or industrial etc.
If it is still not clear enough, let me give you a few examples: The water after rinse and take away the dinner you had digested last night from the toilet, or the dishwasher or washing machine has just outflow into the pipeline after working process, or the industrial water that has just flowed out of the pipe. There is no specific answer. Wastewater is not WASTE, The 99.97 percent of the wastewater is water, and the remaining components include three main physical, chemical, and biological constituents; that’s how wastewater is characterized, most of the constituents are interrelated. In fact, when you are reading this blog and feel thirsty, drink some water. I’d tell you the water you just drink could be wastewater few days ago. Wastewater treatment system in Western Australia takes 450million liters of water from our home every day. This water passes through the 16693km long water pipe into the treatment system, after treatment wastewater can be reused, including drinking or industrial use. Therefore, wastewater learning is closely related to us, which is of great help to environmental protection.
The three characteristics of wastewater we mentioned in the previous section are mainly physical, chemical and biological constituents. In terms of physical constituents; wastewater includes many things such as color, turbidity, temperature and solids, and solid matter uses total solids (TS) as an indicator, including many common things such as what we flush down and soluble paper towels that we had last night. Chemical constituents include heavy metals dissolved in water such as mercury, arsenic, chromium etc. PH value is also one of chemical constituents, concluding that any chemicals dissolved in the water are all chemical constituents. Biological constituents include biologically harmful substances such as bacteria, viruses, and parasites included in wastewater.
Polluted water on the human body would cause many unfavorable problem and disease: 70%-80% of the human body is water, if one person long-term drinks poor quality water, as result in poor physical resistance naturally weakened, then the occurrence of all diseases is inevitable. Waste has been contaminated by heavy metals is Water contaminated by heavy metals is harmful to human health. Water and food contaminated with cadmium will cause kidney and bone disease after eating, and the intake of 20 mg of cadmium sulfate will cause death. Poisoning caused by lead would cause anemia, nervous disorder. Cyanide is also a highly toxic substance. When it enters the bloodstream, it binds to the pigment oxidase of the cell, causing the breathing to be interrupted, causing respiratory failure and suffocation. 80% of the world’s diseases are related to water. Typhoid fever, cholera, gastroenteritis, dysentery, and infectious liver disease are the five major diseases of human beings, all caused by the uncleanness of water. Acids, alkalis, oxidizing agents in wastewater, furthermore such as copper, cadmium, mercury, arsenic, organic poisons such as dichloromethane and ethylene glycol, can poison aquatic organisms and affect drinking water sources. When the organic matter in the sewage is decomposed by microorganisms, the dissolved oxygen in the water is consumed, affecting the life of aquatic organisms such as fish. After the dissolved oxygen in the water is exhausted, the organic matter is anaerobic decomposed to generate unpleasant gases such as hydrogen sulfide and mercaptan, and the water quality would be worse. This is also the possible impact of untreated wastewater on the environment.
Most typical example of wastewater treatment failure: Minamata disease 1956:
Wastewater contains mercury discharged from a nitrogen fertilizer company in Minamata Town, Kumamoto Prefecture, Japan; which is converted into methylmercury after being discharged into the natural water resource. As a result Mercury were enriched in seawater, seabed and fish and it flows through food chain and water chain. At that time, the first disease happened on cats who loved to eat fish. After intoxication, the cats went crazy and jumped into the sea to commit suicide. In a few years, the traces of cats in the Minamata area were gone. In 1956, patients with symptoms like those of cats appeared. Because the cause of the disease is unclear, it is named by the local place name. In 1991, there were 2,248 poisoned patients announced by the Japanese Environment Agency, 1004 died.
Let’s stick this issue with the new idea of 21 century “SDG”-sustainable development goals. Goal six clean water and sanitation. What can we do? Well, this horrible issue definitely could be avoid if they have a sufficient wastewater treatment or people have a GOOD education on wastewater. Why I say a good education level? Since we don’t except everyone be professional engineer or wastewater manager, if the citizen of the village have a basic knowledge of wastewater, this horrible issue wouldn’t happen, isn’t it? So education is so important, even start from kids, let everyone know and learn basic knowledge of wastewater. So in long term of development, everyone knows how to deal with wastewater which match idea with “SDG”.
#get wastED#
Tuesday's sandwich 