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Metal - Polysilicate Flocculant Treatment Of H-acid Analog Dye Wastewater

Posted on:2010-04-07Degree:MasterType:Thesis
Country:ChinaCandidate:W LiangFull Text:PDF
GTID:2191360272994140Subject:Chemical Engineering
Abstract/Summary:PDF Full Text Request
1-Amino-8-naphthol-3,6-disulfonic acid (C10H8NaNO7S2·H2O), known as H-acid, is an important intermediate of naphthalene dyes, which is mainly used in the production of acid dyes, direct dyes, reactive dyes, chromo-tropic acid and so on. But because of environmental reasons, the foreign H-acid plant shutdown, H-acid was in short supply at the domestic market. Because China is the main producing countries of H-acid, so how to improve the H-acid wastewater treatment technology and how to solve H-acid wastewater treatment rationally, are far influence the industry and national economic development. By knowing development situation of coagulant of domestically and abroad, two kinds of inorganic polymer flocculants were prepared and the problem of wastewater treatment containing H-acid were wished to be solved easily and effectively.This research mainly inspected the preparation, flocculation, and mechanism of the two kinds of new inorganic high polymer flocculants PSA and PSAM. The experiment mainly includes four aspects: (1) prepared the poly-silicate and determined the best preparation conditions; (2) prepared PSA and determined the optional preparation conditions; (3) prepared the PSAM on the base of PSA and determined the optional process parameters; (4) XRD, SEM and Si-Mo complexation timed spectrophotometric method were used to analyze PSA and PSAM flocculants. The flocculation mechanism of PSA and PSAM flocculants were revealed on morphology.The results show that when the pH is 4.0, the concentration of SiO2 is 0.3-0.4 mol/L, the poly-silicate has good stability. The decolonization of PSA can nearly reach 60% when the concentration of SiO2 is 0.3mol/L, Al/Si is 1.0, ageing time is 2.0 hours, pH is 2.7and the dosage of PSA is 15ml/L. On the base of PSA, magnesium is added to prepare PSAM. When Mg/Al is 2.0, (Mg+ Al) /Si is 4.0, ageing time is 1h, pH is 2.5 and the dosage is 10ml/L, the PSAM flocculants has the optimal decolonization which is above 90%.The flocculation effects of PSA and PSAM flocculants were compared, it was found that the latter has better flocculability which has enhanced the decolonization about 30% and was more stability. But the settlement capacity of the flocs of PSAM is worse than PSA. Because the flocs of PSAM are quite small, so PAM is used to improve the size and intensity of the flocs and flocculation efficiency of PSAM.A Si-Mo complexation timed spectrophotometric method was used to classify the silicon morphology in polysilicate, PSA and PSAM. The results show that aluminum and magnesium can delay the gelatin time of polysilicate, and magnesium should be better to play the role. The structural characteristics of PSA and PSAM flocculants were analyzed by means of X-ray diffraction spectra and SEM.
Keywords/Search Tags:Polysilicate containing aluminum, Polysilicate containing aluminum and magnesium, H-acid, Si-Mo complexation timed spectrophotometric metho
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