Can the linen washing wastewater be discharged in compliance with the standards?阅读：5272 更新时间：2019-10-16 15:23 Source: Environmental Protection Machinery Co., Ltd. Longxin reading: 5272 Updated: 2019-10-16 15:23
Does a linen washing plant in the suburbs need linen washing wastewater treatment equipment? How much does it cost for a device that discharges about 100 tons of sewage a day, and the most important thing is that it can handle up to standard discharge?
The advantages and characteristics of the linen washing wastewater treatment equipment produced by Shandong Longxin Environmental Protection and its sewage treatment solution. So far, the discharge of linen washing wastewater is getting larger and larger, and the reasonable treatment of the washing wastewater has become an urgent matter. What kind of sewage treatment equipment is the washing sewage treatment equipment?
The waste water from linen washing wastewater treatment equipment is mainly generated from the waste water produced when towels, sheets, and tablecloths are washed, and the waste water is discharged during production. The laundry effluent contains a lot of short fibers and detergent powder foam, which is turbid and sometimes has a deep color. The current wastewater treatment processes mainly include biochemical treatment, membrane treatment, and physical and chemical treatment. For the hotel's laundry room equipment wastewater, although the biochemical treatment process is low in operating costs, the treatment effect is unstable, and the biological bacteria need to be cultured and domesticated. The water temperature of the wastewater is also required. The membrane treatment process is ideal, but the membrane treatment The water discharge capacity is poor and the investment cost is high. According to the characteristics of the hotel's laundry room equipment wastewater, it is better to choose a physical and chemical treatment process. The process is characterized by stable processing results and low equipment investment costs.
I. Analysis of the water quality of linen washing wastewater
Hotel and hotel linen, some places are equipped with a special laundry room, or sent to a professional linen washing factory for cleaning, the amount of laundry is large, the use of water is large, and these laundry wastewater contains more eutrophic substances, If discharged directly, it is easy to eutrophicate surface water.
According to the laundry process, the wastewater of the laundry factory mainly includes laundry wastewater, cleaning wastewater and spin-dry wastewater. Among them, the laundry wastewater accounts for about 30% of the total wastewater, the cleaning wastewater accounts for about 60% of the total wastewater, and the spin-dry wastewater accounts for about the total wastewater. 10% of the amount. And each wastewater has different characteristics: the laundry wastewater contains a lot of short fibers, a lot of detergent powder foam, a high CODCr value, the wastewater is turbid, and sometimes it has a deep color; the amount of cleaning wastewater is large, and there is a small amount of foam. The suspended matter has a lower CODCr value and it appears that the wastewater is more transparent; the amount of spin-off wastewater is small and the water quality is slightly better than the cleaning wastewater.
Second, the common process of linen washing wastewater treatment
According to the main characteristics of laundry wastewater, the treatment processes mainly include chemical coagulation, biological contact oxidation, and a combination of physicochemical and biochemical processes.
1.Coagulation and sedimentation process
The coagulation sedimentation process mainly includes three units: pretreatment, mixed reaction sedimentation and sludge treatment. The wastewater treatment process is simple, efficient, and highly adjustable: it can effectively remove SS and LAS, the COD removal rate reaches 60% to 70%, the LAS removal rate reaches 80% to 90%, and the chroma removal rate reaches 80% to 95%. In addition, the process has a certain ability to resist impact loads.
2.Float-aerated biological filter
Air flotation-aerated biological filter process adds coagulant to wastewater to demulsify and coagulate air flotation, reduce the content of detergents, suspended solids, colloids and other pollutants in water, and then process it through aerated biological filter To the catchment pool. The air-water ratio is greater than 0.5, and the removal rate of BOD5 reaches more than 80%. During the demulsification and coagulation flotation process, the COD removal rate is greater than 55%. The COD removal rate of the aerated biological filter reaches 78.8%. The nitrification efficiency is high. The water quality has reached the "Water Quality Standard for Miscellaneous Water for Domestic Use".
The process has a small floor area, high treatment efficiency, large amount of water treatment, and low energy consumption.
3.Coagulation precipitation-hydrolytic acidification-contact oxidation process
Coagulation precipitation-hydrolytic acidification-contact oxidation process. This process uses hydrolysis and acidification to nitrate the sludge produced by biological contact oxidation. The COD removal rate reaches 86%, the chroma removal rate reaches 90%, and the BOD5 removal rate reaches 92%. The process is easy to operate, easy to maintain, has a small amount of generated sludge, and has good sedimentability.
Third, the specific process of linen washing wastewater treatment
The wastewater is intercepted by the grid to remove solid suspended matter such as waste residues, fibers, etc., and enters the adjustment tank. After the adjustment tank is homogenized and uniform, it is lifted to the flocculation sedimentation tank by a pump. After the coagulant is added to the water, the colloids in the suspended matter Under the interaction of molecular forces and dispersed particles, flocs are formed and they collide and agglomerate with each other during the sedimentation process. Its size and mass continue to increase, and the sedimentation speed increases. After the floc grows to a certain volume, it is under the action of gravity. Separated from the aqueous phase, and then flowed into the A-level biological pool. In the A-level biological pool, the heterotrophic bacteria hydrolyzed the soluble organic matter in the sewage into organic acids, decomposed the large organic matter into small molecular organic matter, and the insoluble organic matter was converted into soluble organic matter. Ammoniating of pollutants such as protein and fat. There are aerobic microorganisms and digestive bacteria in the O-level biological pool section. Among them, aerobic microorganisms decompose organic matter into CO2 and H2O. Under sufficient oxygen supply conditions, the nitrification of nitrifying bacteria oxidizes NH3-N to NO3-, which is controlled by reflux. Return to Class A biological pool. Under hypoxic conditions, the denitrification of the aerobic bacteria will reduce NO3- to molecular nitrogen. It will contact the effluent of the oxidation tank to flow into the sedimentation tank for sedimentation, and the effluent from the sedimentation tank will enter the clear pond. Discharged after a short stay in China.