A method for treatment of mixed electroplating wastewater without a cyanide and a phosphorus-containing reductant without a cyanide and a phosphorus-containing reductant. A ferrous chloride solution is added into electroplating wastewater without a cyanide and a phosphorus-containing reductant. The pH of wastewater is adjusted to 10.5-12. Pollutants such as sodium cyanide and hydroxyl-containing organic amine complexants are oxidized with sodium hypochlorite. Carboxyl-containing organic acid complexants are precipitated. Hexavalent chromium is reduced to trivalent chromium to form chromium hydroxide precipitate. Precipitate is removed by filtering and wastewater is adjusted to pH 4.5-5.5. Heavy metal ions are precipitated with sodium dimethyldithiocarbamate or sodium diethyldithiocarbamate. Precipitate and heavy metal capturing agents are adsorbed with activated carbon followed by removal of precipitate. Wastewater is adjusted to pH 6-8. Aliphatic polyamine complexants are destroyed using an available biological degradation technique to reduce chemical oxygen demand.
C02F 101/38 - Composés organiques contenant de l'azote
C02F 101/34 - Composés organiques contenant de l'oxygène
C02F 101/22 - Chrome ou composés du chrome, p. ex. chromates
C02F 103/16 - Nature de l'eau, des eaux résiduaires ou des eaux ou boues d'égout à traiter provenant de procédés métallurgiques, c.-à-d. de la production, de la purification ou du traitement de métaux, p. ex. déchets de procédés électrolytiques
C02F 1/72 - Traitement de l'eau, des eaux résiduaires ou des eaux d'égout par oxydation
2.
Method for integrated treatment of electroplating wasterwater
A method for integrated treatment of electroplating wastewater includes steps of: adjusting and maintaining pH of wastewater at 10.5-12; oxidizing pollutants such as sodium cyanide and hydroxyl-containing organic amine complexants with sodium hypochlorite; precipitating carboxyl-containing organic acid complexants with synergistic effect of ferrous and calcium ions; reducing hexavalent chromium to trivalent chromium and forming chromium hydroxide precipitate; removing precipitate by filtering; adjusting wastewater to pH of 4.5-5.5; precipitating heavy metal ions with sodium dimethyldithiocarbamate or sodium diethyldithiocarbamate; adsorbing precipitate and heavy metal capturing agents with activated carbon; filtering to remove precipitate; adjusting wastewater to pH of 6-8; and destroying aliphatic polyamine complexants and reducing COD using an available biological degradation technique. This method can effectively and economically remove the pollutants such as heavy metals in the electroplating wastewater for a good market prospective.
C02F 101/38 - Composés organiques contenant de l'azote
C02F 101/34 - Composés organiques contenant de l'oxygène
C02F 101/22 - Chrome ou composés du chrome, p. ex. chromates
C02F 103/16 - Nature de l'eau, des eaux résiduaires ou des eaux ou boues d'égout à traiter provenant de procédés métallurgiques, c.-à-d. de la production, de la purification ou du traitement de métaux, p. ex. déchets de procédés électrolytiques
C02F 1/72 - Traitement de l'eau, des eaux résiduaires ou des eaux d'égout par oxydation
3.
Method for treating electroless copper plating wastewater
A method for combined treatment of electroless copper plating wastewater includes oxidizing hydroxyl-containing organic amine complexants with hydrogen peroxide or sodium hypochlorite to organic acid complexants containing amine group (or amino group) and carboxyl group, precipitating the carboxyl-containing complexants using synergistic effect of ferrous ions and calcium ions and precipitating the copper ions released from the complexes to copper hydroxide precipitate to effectively removing copper. Using this precipitation method to remove complexants in the electroless copper plating wastewater, the problem in the prior art that it is difficult to destroy the hydroxyl-containing organic amine complexant is solved and the COD in the wastewater is effectively reduced.
C02F 1/72 - Traitement de l'eau, des eaux résiduaires ou des eaux d'égout par oxydation
C02F 1/70 - Traitement de l'eau, des eaux résiduaires ou des eaux d'égout par réduction
C23C 18/16 - Revêtement chimique par décomposition soit de composés liquides, soit de solutions des composés constituant le revêtement, ne laissant pas de produits de réaction du matériau de la surface dans le revêtementDépôt par contact par réduction ou par substitution, p. ex. dépôt sans courant électrique
C02F 1/52 - Traitement de l'eau, des eaux résiduaires ou des eaux d'égout par floculation ou précipitation d'impuretés en suspension
C02F 103/16 - Nature de l'eau, des eaux résiduaires ou des eaux ou boues d'égout à traiter provenant de procédés métallurgiques, c.-à-d. de la production, de la purification ou du traitement de métaux, p. ex. déchets de procédés électrolytiques
4.
Hydroxyl graphene-modified plating sealants and preparation methods thereof
A hydroxyl graphene-modified plating sealant and a preparation method thereof are disclosed. The plating sealant comprises a film-forming material, a resist, a defoaming agent, a levelling agent, and deionized water; the resist is a nanoscale hydroxyl graphene aqueous solution comprising hydroxyl graphene having a mass fraction of 3.5% to 4% and a pH of 8.0 to 9.5. Nanoscale hydroxyl graphene is used as a resist in the plating sealant of the disclosure, then the hydroxyl groups on hydroxyl graphene can react with the hydroxyl groups of the film-forming material, i.e. silica sol and the silane polymer, by dehydration condensation, thereby significantly improving the performance of the sealing film. The sealing film has higher corrosion resistance and abrasion resistance compared with that prepared by graphene or reduced graphene oxide sealant.
Provided are a hydroxyl graphene modified clad layer sealant and a preparation method therefor. The sealant comprises a film-forming material, a corrosion resistant agent, a defoamer, a leveling agent and deionized water. The corrosion resistant agent is a nano-sized hydroxyl graphene aqueous solution having a mass fraction between 3.5% and 4% and a pH value between 8.0 and 9.5. The sealant uses the nano-sized hydroxyl graphene as the corrosion resistant agent, and the hydroxyl group on the hydroxyl graphene can be condensed with the hydroxyl group in the film-forming material, i.e. a silica sol, and the silane polymer, thereby significantly improving properties of the sealed film. The sealed film has higher corrosion resistance and abrasion resistance than graphene or redox graphene.
Disclosed is a method for treating alkaline zinc-nickel alloy electroplating wastewater, the method involving adjusting the pH of alkaline zinc-nickel alloy electroplating wastewater to 3-4, adding an aqueous solution of sodium diethyldithiocarbamate to precipitate zinc and nickel, and adding a flocculant to make precipitated particles aggregate; adjusting the pH of the electroplating wastewater to 4.5-5.5, and further adding a sodium hypochlorite solution; and adjusting the pH of the treated electroplating wastewater to 6-9.
C02F 9/04 - Traitement en plusieurs étapes de l'eau, des eaux résiduaires ou des eaux d'égout une étape au moins étant un traitement chimique
C02F 103/16 - Nature de l'eau, des eaux résiduaires ou des eaux ou boues d'égout à traiter provenant de procédés métallurgiques, c.-à-d. de la production, de la purification ou du traitement de métaux, p. ex. déchets de procédés électrolytiques
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