A Step-by-Step Guide to the Waste Water Treatment Process

1. A Step-by-Step Guide to the Waste Water Treatment Process

2. WASTE WATER TREATMENT PROCEDURE (ELECTROPLATING AND METALFINISHING) Environmental issues are one of the core issues of concern to the whole of society. In addition to living waste, waste in industrial production is considered to cause severe environmental damage. Industrial plants and factories, besides bringing enormous benefits to the national economy, their volume of waste is always large and diversified in terms of types, causing environmental pollution. More importantly, it requires people to have proper awareness and proper investment in waste treatment, especially wastewater treatment. In particular, the metalworking industry, the amount of electroplating and metalfinishing from metalworking is potentially destructive to the environment and requires a properly designed waste treatment system to Help reduce water pollution as well as protect human health.

3. Products of the plating industry (Electroplating and Metalfinishing) Where does electroplating and metalfinishing come from? The source of sewage from plating is mainly from the production of factories, factories and the quality of the plating water depends on the type of production, technological lines, raw materials, product quality ... Waste water from production in factories is divided into two types: the waste from the process of plating and the process of cleaning the surface of details. Waste water from plating: The solution in the galvanized tank may be leaking, splashing, or sticking to the platens and out. After a period of operation, the galvanic tanks must be cleaned so that the dirt and sludge are discharged into the wastewater stream. As a result, the amount of wastewater is not much, but the pollutant is diverse, the concentration of pollutants is high (Cr6 +, Ni2 +, CN-).

4. Waste water from the surface cleaning process details: On the metal surface there is usually grease attached to it due to mechanical maintenance and polishing. In order to ensure the quality of the plating of parts prior to coating, it is necessary to clean the surface by chemical grease, solvent or electrochemical degreasing. As a result, the amount of wastewater generated during this process is small but the concentration of pollutants is small, mainly alkaline, acid and solution. Composition and properties of electroplating and metalfinishing. Plating wastewater has a wide range of concentrations and pH varies widely from acid (pH = 2 - 3) to very alkaline (pH = 10 - 11). The common feature of plating wastewater is that it contains high levels of inorganic salts and heavy metals. Metallic lobes of the class where the source of contamination can be Cu, Zn, Cr, Ni, ... and also depending on the metal salts used which contain toxins such as cyanide, sulfate, ammonium, Chromates, ... Organic substances are less common in plating water, mainly cotton, surfactants ... so BOD, COD are often low and not subject to treatment. The main treatment is inorganic ions, especially heavy metal salts such as Cr, Ni, Cu, Fe, etc.

5. Wastewater should be separated into 3 separate streams: Concentrated solution from dipping tanks, immersion tanks. Water washing equipment has medium content of dirt (metal salts, grease and soap, ...) Water diluted For safety and ease of processing, chromic acid and cyanide are separated. The contaminated sewage water can be divided into several groups: Toxins such as CN-, Cr6 +, F-, ... Contaminants change pH such as acid and alkaline streams Contaminants form suspended particles such as hydroxide, carbonate and phosphate Organic pollutants like grease, EDTA ...