The odor produced by urban sewage treatment plants during operation is generally fishy, ​​ammonia smell, rotten meat smell, rotten egg smell, rotten cabbage smell, fetid odor and the special smell of some production wastewater. Odor treatment methods include direct incineration, catalyst oxidation, acid-base wash, odor oxidation, chemical reaction, activated carbon physical adsorption, biological deodorization, soil deodorization and so on. Described in detail below several deodorant method. 1, soil deodorization 1.1 Principles and characteristics Soil deodorization mechanism can be divided into two types: physical adsorption and biodegradation. Water-soluble malodorous gases (such as amines, hydrogen sulfide, and lower fatty acids) are absorbed and removed by soil moisture, while insoluble odor is physically adsorbed by soil surface It is then broken down by microorganisms in the soil. Soil deodorant method is characterized by: First, low maintenance and management costs, deodorant effect and the equivalent of activated carbon; Second, covers an area of ​​more than 2.5-3.3m2 / m3 of gas; Third, not suitable for heavy snow and snowy areas, for high temperature, high humidity and water dust and other gases to be pre-treated. 1.2 design parameters When soil deodorization is selected, humic soil is the best indicator of soil deodorization. Red soil such as loam and clay should be mixed with chicken manure, garbage and sludge and fertilizers for improvement. Minerals and clays should not be used. Soil moisture to 40% -70% is appropriate. Too dry soil requires a water sprinkler. The surface of the soil on which the lawn is planted is tilted as a measure to prevent heavy rains. After several domestic and foreign soil deodorization bed practice, odor through the soil speed of 2-17mm / s, the design is generally selected 5mm / s effective soil thickness of 50cm, odor and soil contact time of 100s. 2, chemical reaction deodorant 2.1 chlorination deodorant This method is the use of chlorine disinfection sterilization to remove organic matter in the water to kill algae; disinfection of the water to make it to maintain a certain amount of residual chlorine to ensure the effectiveness of sterilization. Adopt the pre-disinfection of chlorine in the inlet pipe network to control the odor. 2.2 H2O2 control foul The mechanism of using H2O2 to control the malodor is that the reaction between H2O2 and H2S takes place under the pH of the urban sewage and finally the elemental sulfur and water are generated: H2O2 + H2S ------ S + 2H2O The actual efficiency of this reaction is governed by many factors, the most important of which are the effective reaction time and the duration of the reaction, with the best times being 5-20 min and 1-2 h, respectively. Experimental studies have shown that the actual dosage of the drug in operation under the optimum conditions is close to the theoretical calculation. Residual H2O2 in the sewage will eventually decompose into water and oxygen, and will not form some of the harmful substances with the organic matter. This confirms the monitoring of dissolved oxygen in water, which follows a stoichiometric relationship between the increase in dissolved oxygen in water and excess H2O2: 1 g of H2O2 will produce 0.5 g of dissolved oxygen. 2.3 a sewage treatment plant pilot test results The sewage treatment plant is a secondary treatment plant with a processing capacity of about 164 * 104 m3 / d. The plant uses a method of strengthening primary sediment (FeCl3 and anionic polymers) to maximize BOD removal. Studies show that there are two main sources of sulfide in pretreatment structures: NORs and NCOs collection systems (H2S flowing into each system accounting for 45% of the total plant load). A mild climate has a liquid sulphide concentration of about 2.5-4.5 mg / L and a sulphide concentration of about 125-200 mg / L into the pretreatment scrubber. The results show that the concentration of H2S entering the primary settler scrubber is reduced by 50% -90%, depending on the dosing rate. After the addition of H2O2 a large number of environmental odor reduction, secondary treatment facilities in the oxygen transmission rate also increased significantly. Four Edge Sealing Bag Packing Machine Four Edge Sealing Bag Packing Machine Four Edge Sealing Packing Machine,Automatic Bag Packing Machine,Ultrasonic Packing Machine,Powder Packaging Machine Dongguan Pailade Machinery Equipment Co.,Ltd , https://www.pailade.com