Online Preparation Of Poly Iron And Its Application In Oilfield Wastewater Treatment

This paper explores a new method to generate poly-iron online, online generated environment for the Liaohe oilfield wastewater (pretreated water sample COD=420 mg·L-1), the process will gather iron generation and oilfield wastewater treatment integrated is done, the two combined, not only saving time, easy to operate, but also using the strong flocculation of the new eco-ferric, improving their efficiency oilfield wastewater treatment, and reduce the dosage, low processing costs. Main experiment contents of this paper are:(1)This paper studied four methods to generate poly-iron online, including hydrogen peroxide method, nitric acid oxidation, calcium hypochlorite oxidation method and potassium persulfate oxidation method, and choose the optimum solution. The treatment effect of hydrogen peroxide oxidation method for water samples is the best, the effluent COD=76.5 mg·L-1, and COD removal rate could reach 81.79%; The following is persulfate oxidation method, the effluent COD=108.42 mg·L-1, and COD removal rate could reach 74.19%. This paper do further research on these two methods.(2)In the paper, the precipitate generated in the hydrogen peroxide oxidation system was studied with qualitative identification, by infrared spectroscopy and XRD spectra analysis. The results show that the newly formed iron generated in the system are poly iron bridged by hydroxyl. The Fe(Ⅲ) in the new formed iron are analyzed by the method of time-by-time complexation colorimetry. The contents of Fe (a), Fe (b) and Fe (c) are 60.8%,17.5% and 21.7% respectively. In order to study the relationship between oxidation and flocculation in the system, this paper select a representative matter-benzene. For example, studying its reactions in the system by analyzing its spectrum, the system generated ·OH polymerization initiator having the role of the small molecules substance into easily removed macromolecules flocculation process.(3)At the same time, the precipitate generated in the potassium persulfate oxidation system was studied with qualitative identification, the results show that the newly formed iron generated in the system are poly iron bridged by hydroxyl. In order to study the relationship between oxidation and flocculation in the system, this paper select a representative matter-benzene. For example, studying its reactions in the system by analyzing its spectrum, the result shows that under the oxidation of ·SO4-, most of the organic compounds were degraded into small molecules alkanes. And under the aggregation of ·SO4-, these small molecules were aggregated into larger particles, which can be easily removed by the newly-formed ferric. So the water sample can be treated.