Wastewater treatment plants can produce many toxic and harmful gases, such as methane (combustible gas), hydrogen sulfide, carbon monoxide and carbon dioxide. Aeration basins and sludge nitrification are the main locations for biogas production. This essentially depends on the main pollutants contained in the wastewater. Biogas is indeed present.
The main gaseous components produced in wastewater treatment plants are nitrogen (N2), oxygen (O2), carbon dioxide (CO2), hydrogen sulfide (H2S), ammonia (NH3) and methane (CH4). certain gases that produce odors, such as amines, mercaptans, organic sulfides, skatole, indole and other VOC trace gases. Among them, nitrogen (N2), oxygen (O2) and carbon dioxide (CO2) are common components in the air. They do not harm wastewater treatment plants and do not need to be treated.
With the development of new energy vehicles and electronic products, the demand for lithium batteries is also increasing. The cathode material is one of the cores of lithium batteries. Commercially available cathode materials include lithium cobalt oxide, lithium iron phosphate, and ternary materials. The ternary material is lithium-nickel-cobalt-manganate Li (NiCoMn)O2, which is the cathode material for new energy vehicles such as long-range and fast-charging vehicles.
Ternary materials mainly consist of ternary precursor materials (nickel-cobalt-manganese hydroxide), lithium carbonate and various additives. Firstly, the raw materials and additives are put into a high-speed mixer in a certain proportion to be mixed, then the mixture is heated in a roller oven, and then ground by a pulverifier. The crushed material is wrapped with a packaging agent. heated and sprayed again, and can be stored after final inspection.
The raw materials are all in powder form, so some raw materials or materials that have not reacted sufficiently will remain on the equipment. Therefore, when the equipment is cleaned, the wastewater will contain raw material residue. materials. This is also the main reason for wastewater of ternary materials. There is also wastewater from daily cleaning of workshop floors, which is the main source of ternary material wastewater.
Raw materials contain cobalt ions, manganese ions, lithium ions and other additives. Therefore, ternary pollutants in wastewater contain metal ions, COD, SS, ammoniacal nitrogen and other pollutants. These substances are difficult to biodegrade and are heavy metal substances. They cannot be released directly into the body of water. treatment process before they can be released into the water body.
Here are some ternary material wastewater treatment processes, which need to be adjusted according to the actual wastewater conditions.
1. Physical method, the grid is a metal frame made up of a set of parallel metal bars, placed obliquely on the channel where the wastewater flows, or on the pumping station. The basin inlet serves to intercept large pieces of suspended or floating solid pollutants. Large particles present in wastewater of ternary materials can be intercepted and usable materials can be recovered.
2. Physical and chemical treatment method for separating and removing heavy metals in water, the waste water is pumped through the polift pump to the sedimentation basin and the flocculant is added (can be added during the pumping process). Colloids and dispersed particles of suspended matter form flocs under the interaction of molecular forces, and they collide and agglomerate with each other during the sedimentation process. Their size and mass continue to increase, the sedimentation rate continues to increase, and eventually they precipitate. .
3. The gas stripping method removes most of the ammoniacal nitrogen present in the water and passes the water vapor into the wastewater. When the steam pressure in the wastewater exceeds the external pressure, the wastewater. begins to boil. This accelerates the process of transferring volatile substances from the liquid phase to the vapor phase. Additionally, when water vapor passes through the water layer in the form of bubbles, a free surface is formed ebetween water and bubbles. At this time, the liquid continuously evaporates and diffuses into the bubbles as the bubbles rise toward the liquid. surface, they burst and release the volatile substances they contain.
Internal materials still have limitations, which also involve price and safety issues, so lithium iron phosphate is still competitive in the market. External materials continue to develop and become a trend, and wastewater treatment can not only reduce business costs, but also recycle useful substances.