Method for pretreating canned citrus petal production wastewater and recycling pectin simultaneously

Abstract

The invention relates to a method for pretreating canned citrus petal production wastewater and recycling pectin simultaneously. The method is characterized by comprising the following steps: (1) filtering: removing solid impurities of more than 5 mm in acid-base cleaning wastewater in the front part of the canned citrus petal production procedure; (2) detecting the wastewater indexes: regulatingthe pH of the wastewater to be lower than 5, adding 1 mg / L of CaCL2; (3) regulating and electrolyzing: introducing the regulated wastewater into a copper-stainless steel electrode system, applying a direct current voltage of 5-60 V, treating for 20-120 minutes; (4) precipitating: precipitating the treated wastewater for more than 30 minutes to obtain a relatively clear supernate and a pectin precipitate; (5) coagulating and precipitating: regulating the pH value of the wastewater, and adding 3-10 mg / L PAM coagulant of 0.5%(w / w). The CODCr (Chemical Oxygen Demand) of the wastewater is obviouslyreduced while the colloid like the pectin is coagulated, the purpose of pretreating the canned citrus petal production wastewater relatively efficiently cleanly / greenly is fulfilled, and meanwhile, the pectin ingredient in the wastewater is greatly recycled.

Description

technical field [0001] The invention relates to a technology for green pretreatment of canned citrus production wastewater and capable of recovering most of the pectin at the same time, which can be used for the treatment of canned citrus production wastewater or the recovery of pectin in the wastewater. Background technique [0002] As the country with the largest production volume of canned citrus in the world, my country produces waste water containing citrus pods, citrus sacs and pectin in its front acid and alkali treatment section, which makes it difficult to treat compared with ordinary food waste water. The successful treatment process is a coagulation-air flotation / sedimentation-enhanced biochemical process mainly for pectin, and its typical configuration is to set coagulation-air flotation units in the pretreatment and / or tail. As far as production enterprises are concerned, it often leads to the shortage of fixed investment and large occupied area of ​​wastewater tr...

AI Technical Summary

Problems solved by technology

[0002] As the country with the largest production volume of canned citrus in the world, my country produces waste water containing citrus pods, citrus sacs and pectin in its front acid and alkali treatment section, which makes it difficult to treat compared with ordinary food waste water. The successful treatment process is a coagulation-air flotation / sedimentation-enhanced biochemical process mainly for pectin, and its typical configuration is to set coagulation-air flotation units in the pretreatment and / or tail. As far as production enterprises are concerned, it often leads to the shortage of fixed investment and large occupied area of ​​wastewater treatment stations; at the same time, pectin is slowly released in wastewater, and it is difficult for the coagulation process at the head of the process to exert its maximum effect, which is extremely It is easy to cause the disadvantages of complex management of wastewater treatment system, large residual aluminum salt (or other metal coagulants), fragile and inefficient biochemical system, large scum production and difficult to handle

At the same time, pectin dispersed in wastewater is indeed a component with great economic and application value. During the discharge and treatment of wastewater, it not only pollutes the environment, but also consumes a lot of chemicals and energy to treat it.

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