CS216299B1

CS216299B1 - Method of precleaning the concentrated coloured refuse waters from the production of the n-phenyl-n-izopropyl-p-phenylenediamine

Info

Publication number: CS216299B1
Application number: CS209881A
Authority: CS
Inventors: Stefan Regula; Pavol Klucovsky
Original assignee: Stefan Regula; Pavol Klucovsky
Priority date: 1981-03-23
Filing date: 1981-03-23
Publication date: 1982-10-29

Description

Vynález isa týká sposobu predčistenia koncentrovaných farebných odpadových vod z výroby N-fenyl-N’-izopropyl-p-fenyléndiamínu, pri ktorom sa na upravenú odpadovú vodu po neutralizácii pósobí aktívnym chlórom, například vo formě chlornanu sodného.The invention also relates to a process for the pre-treatment of concentrated colored waste water from the production of N-phenyl-N '-isopropyl-p-phenylenediamine, in which treated waste water is treated with active chlorine, for example in the form of sodium hypochlorite, after neutralization.

Pri výrobě antioxidantů N-fenyÍ-N’-izopropyl-p-fenyléndiamínu vznikajú koncentrované odpadové vody, ktoré v dosledku intenzívnelho hnedočerveného zafarbenia sa rnedajú zneškodňovat nariedením inými bezfarebnými vodami. Podobný typ odpadových vod, například z výroby 4-aminodifenylamínu sa doposial’ známým sposobom čistí tak, že sa časť znečisťujúcich farebných látok odstraní neutralizáciou odpadovej vody minerálnou kyselinou. Po úpravě pH iz póvodnej hodnoty 13,0 až 13,5 na pH 7 až 5 sa vylúči časť farebných látok vo formě nerozpustnej zrazeniny, ktorá sa dá běžným sposobom odfiltrovat. Po odfiltrovaní vypadnutej zrazeniny sa ^neutralizovaná odpadová voda chló216299 ruje plynným chlórom s prebytkom 100— 200 .mg . Γ¹. Vylúčený kal sa odstráni sedimentáciou alebo filtráciou.In the preparation of the N-phenyl-N'-isopropyl-p-phenylenediamine antioxidants, concentrated waste water is produced which, due to the intense brown-red coloration, cannot be disposed of by dilution with other colorless waters. A similar type of waste water, for example from the production of 4-aminodiphenylamine, is treated in a manner known per se by removing part of the contaminating colorants by neutralizing the waste water with mineral acid. After adjusting the pH from an initial value of 13.0 to 13.5 to a pH of 7 to 5, some of the colored substances precipitate in the form of an insoluble precipitate which can be filtered off in a conventional manner. After filtering off the precipitated precipitate, the neutralized effluent is treated with chlorine gas with an excess of 100-200 mg. Γ ¹ . The precipitated sludge is removed by sedimentation or filtration.

Použitie plynného chlóru vedla pozitívneho odfanbovacieho efektu má aj nevýhody. Tieto spočívajú predovšetkým v spósobe zabezpečenia optimálneho sposobu dávkovania pri zmene kvality a množstva odpadových vod, zvlášť pri nepředvídaných havarijných stavoch vo výrobě. Ďalšou nevýhodou použitia plynného chlóru móže byť jeho predávkovanie, ktoré spósobí, že vzniknutý chemický kal je lepivý a z toho dovodu sa nedá z predčistenej odpadovej vody odstrániť filtráciou. Tieto nevýhody odstráni podlá vynálezu spósob predčistenia koncentrovaných farebných odpadových vod z výroby N-fenyl-N’-izopropyl-p-fenyléndiamínu, pri ktorom sa časť znečisťujúcich látok odstráni neutralizáciou minerálnou kyselinou na pH 5 až 7 a ich zvyšok ohloráciou, chlorácia sa uskutočňuje posobením aktívneho chlóru vo formě ohlórňanu sodného, ktorý sa použije v množstve 3 až 6 s výhodou 5 objemových % na daný objem upravovanej odpadovej vody. Odpadová voda po odstránení zrazeniny, vypadnutej pri neutralizácii ostává i naďaiej farebná, pričom farébnosť odpovedá 3500 až 3200 mg Pt. I'¹. K priamemu odstráneniu farebnosti bolo by potřebné takto upravená vodu nariediť v pomere 1 :150 až 1 :170 objemových dielov bezfarebnej vody. Prídavkom chlórňanu sodného možno z takej to vody takmer kvantitativné odstrániť zvyškové farebné látky pósobením afctívneho chlóru. Po jeho reakcií s rozpuštěnými farebnými organickými látkami sa tieto prevedú na nerozpustná formu a z roztoku vylúčia vo formě chemického kalu, ktorý sa odstráni mechanicky, například filtráciou alebo sedimentáciou. V dosledku toho, dojde k odfarbeniu odpadovej vody do takej miery, že po jej nariedení v pomere 1 :10 nie je farebnosť postrehnutefná. Výhoda použitia aktívneho chlóru vo formě chlórňanu sodného spočívá hlavně v tom, že chlórňan sodný má definovaný obsah aktívneho chlóru a z toho dóvodu ho možno presne dávkovat a tým mi-The use of chlorine gas in addition to the positive blow-off effect also has disadvantages. These consist mainly in ensuring the optimum dosing method when changing the quality and quantity of waste water, especially in unforeseen production emergency situations. Another disadvantage of using chlorine gas may be its overdose, which causes the resulting chemical sludge to be sticky and therefore cannot be removed from the pre-treated wastewater by filtration. According to the invention, these disadvantages are eliminated by the method of pre-treatment of concentrated colored waste water from the production of N-phenyl-N'-isopropyl-p-phenylenediamine, in which part of the pollutants is removed by neutralization with mineral acid to pH 5-7 and their remainder by chlorination % of active chlorine in the form of sodium hypochlorite, which is used in an amount of 3 to 6, preferably 5% by volume, for a given volume of treated waste water. The waste water after removal of the precipitate precipitated by neutralization remains colored, the color of which corresponds to 3500 to 3200 mg Pt. I ' ¹ . In order to directly remove color, it would be necessary to dilute the treated water in a ratio of 1: 150 to 1: 170 parts by volume of colorless water. By adding sodium hypochlorite, residual colored substances can be almost quantitatively removed from such water by the action of affective chlorine. After its reaction with dissolved colored organic substances, these are converted to an insoluble form and excreted as a chemical sludge which is removed mechanically, for example by filtration or sedimentation. As a result, the waste water becomes discolored to such an extent that after diluting it in a 1: 10 ratio, the color is not perceptible. The advantage of using active chlorine in the form of sodium hypochlorite lies mainly in the fact that sodium hypochlorite has a defined content of active chlorine and therefore it can be accurately dosed and thus

Claims

SUBJECT

A process for the pre-treatment of concentrated colored wastewater from the production of N-phenyl-N '-isopropyl-p-phenylenediamine, wherein a portion of the contaminating colorants is removed by neutralization with mineral acid to pH 7 to 5 and their remainder chlorinated to minimize excess chlorine in the treated water. Excess chlorine causes the sticky character of the precipitated chemical sludge, making it difficult to remove it mechanically from the waste water.

The following is an example of a practical embodiment of the invention.

2000 ml of concentrated waste water from the production of N-phenyl-N'-isopropyl-p-phenylenediamine having a pH of 13.3 was neutralized by adding 185 ml of concentrated hydrochloric acid to pH 6.3. The precipitated chemical sludge in an amount of 101.2 g was filtered off. To the filtrate with stirring was added 60 ml of a 145 g solution of sodium hypochlorite over 30 minutes. Γ ¹ and the mixture was allowed to stir for an additional 30 minutes. Then the resulting sludge in an amount of 82.4 g was filtered off. The effluent treated was a slightly yellowish color corresponding to 300 mg Pt. I ¹ . After 1:10 dilution with colorless water, the color of the wastewater was not observed.

OF THE INVENTION in that the chlorination is carried out by imparting active chlorine in the form of a solution of sodium hypochlorite having a concentration of 140 to 150 g of chlorine. ¹ , which is used in an amount of 2 to 5, preferably 3% by volume per volume of treated waste water.