2.2.5 Superwater heats and evaporates ordinary water into steam in a closed container, and makes the steam condense in a timely capillary (the inner diameter is in the order of nm). The water thus obtained is called super water, and some people call it nano water unscientifically. After treatment, the super-water association structure changed greatly, and a chain-like hexagonal ring structure polymer was formed, and its particle size reached the order of nm. Because of the particularity of super-water structure, it has some properties different from ordinary water: ① its density is 1.4 times that of ordinary water (ρ chao =1.4 ρ pu); ② Its viscosity coefficient is 15 times higher than that of ordinary water (η Chao = 15η Pu) and its volatility is low; ③ The freezing point of super water is-100℃, and it still maintains its characteristics at 700℃. When heated to 900~ 1000℃, it becomes common water, and its characteristics will not change whether it is heated, cooled or stored for a long time at-100~700℃. Superwater has high activity and can easily enter between molecules of other substances. Some substances incompatible with ordinary water, such as fuel oil, can be well dissolved with super water, and water enters between oil molecules, which changes the interaction between molecules and makes the molecular structure more loose. Fuel oil containing a certain proportion of super water has low ignition point and full combustion. On the one hand, it can improve the combustion rate and mechanical efficiency, on the other hand, it can reduce air pollution, which has great economic and social benefits. Using super water as solvent, it can be made into liquid solution at low temperature. According to its low volatility and high viscosity coefficient, it can also be made into volatile and impermeable solution, which is of great use in industry.
2.2.6 Reclaimed water refers to high-quality miscellaneous drainage (excluding feces and kitchen drainage), miscellaneous drainage (excluding feces and sewage) and domestic sewage (wastewater) used by people in life and production, which can reach a certain water quality standard and can be reused in a certain range, and its water quality is between the upper water (clear water) and the lower water (sewage). There are many explanations for "reclaimed water". It is called "reclaimed water" in sewage engineering, "circulating water" or "reclaimed water" in factories, and some people call it "reclaimed water". Generally, water quality is used as a distinguishing sign. The treated reclaimed water quality must meet the following conditions: (1) It meets the hygiene requirements: its indicators mainly include coliform bacteria, total bacteria, residual chlorine, suspended solids, COD, BOD5, etc. (2) Satisfy people's sensory requirements, without unpleasant feelings, and its measurement indicators include turbidity, chromaticity, smell, etc. (3) Meet the requirements of equipment structure, that is, the water quality is not easy to cause serious corrosion and scaling of equipment and pipelines, and its measurement indicators include PH value, hardness, evaporation residue, dissolved substances, etc. The treated wastewater is generally used for flushing toilets, spraying roads, greening, car washing and as supplementary water for cooling water.
2.3 Hard water and soft water
2.3. 1 Soft water contains little or no calcium ions and magnesium ions. Generally, water with hardness below 8 degrees is soft water.
2.3.2 Hard water contains more calcium ions and magnesium ions. Generally, water with hardness higher than 8 degrees is hard water. Hard water will affect the effect of detergent, and heating with hard water will have more scale. Generally speaking, hard water should be softened before it is used in industry.
2.4 Fresh water and salt water
2.4. 1 Fresh water with little or no salt is generally used as domestic water or industrial water.
2.4.2 Salt water contains more salt, such as salt lake water in the north, and some groundwater and seawater are salt water.
Investigation and analysis on water quality of Yangtze River and ancient canal
10 June 16 and June 17, five of our classmates went to the ancient canal in Zhenjiang, Neijiang in the Yangtze River and nearby areas, and brought back water samples. Under the guidance of the teacher, the pH value, suspended matter, sediment content, COD and transparency of these water samples were analyzed. The analysis results show that the water quality of the outer river in the Yangtze River basin is good, which basically meets the national requirements. Neijiang and the ancient canal are seriously polluted and the water is turbid. In some places, the water quality turns yellow or green, and there are many suspended substances. In some areas, the water body has pungent smell and siltation. The water quality in most areas only meets the national class III or IV standards, and a few areas are seriously not up to standard. In view of the above situation, several of our classmates visited some experts and made a survey on the relevant situation. The reasons for the deterioration of water quality in Neijiang and the ancient canal are as follows. First, the overall layout of Zhenjiang city is not reasonable. There are many industries along the river, and the residential areas along the ancient canal are dense. Second, some industrial wastewater is discharged into Neijiang and the ancient canal when it is not up to standard, and even some manufacturers directly discharge untreated wastewater in order to reduce production costs. Third, the domestic sewage in the community is directly discharged into Neijiang and the ancient canal without purification, and the phenomenon of littering along the ancient canal is very serious. Some citizens urinate anywhere by the river. Fourth, the management of the environmental protection department is not in place, the inspection is not strong enough, and the punishment for violators is not severe. For Zhenjiang to have a good ecological environment, for Zhenjiang to become a famous sanitary city and tourist city in China, for the health of our Zhenjiang citizens and for the rapid development of our future generations, we strongly call for strengthening the governance of Neijiang and the ancient canal and improving its water quality. We put forward the following suggestions: First, the city leaders make an overall plan for Zhenjiang City, and forcibly close or relocate enterprises with serious pollution. Second, enterprises in urban areas should improve their pollution discharge capacity and self-purification, not for their own interests, regardless of the life safety of urban people. Third, it is everyone's responsibility to establish environmental awareness and protect the water quality of Neijiang and the ancient canal. Don't litter at will. Fourth, environmental protection departments should improve their sense of responsibility, strengthen environmental supervision, and put an end to the random discharge of industrial wastewater and domestic sewage.
The above survey report is just a superficial study made by five of our classmates in their spare time. This is our first attempt in the comprehensive practical activity class in senior high school, and there are many shortcomings. I hope teachers and students can correct me. Thanks to the teacher's careful guidance and great help, and heartfelt thanks to the classmates, teachers, leaders and social enthusiasts who have helped us.