Thanekar Pooja, Gogate Parag R
Department of Chemical Engineering, Institute of Chemical Technology, Matunga, Mumbai 40019, India.
Department of Chemical Engineering, Institute of Chemical Technology, Matunga, Mumbai 40019, India.
Ultrason Sonochem. 2019 May;53:202-213. doi: 10.1016/j.ultsonch.2019.01.007. Epub 2019 Jan 8.
In the present work, hydrodynamic cavitation (HC) operated alone and in combination with chemical oxidants has been applied for the treatment of real industrial effluent obtained from a local industry. Initially, the analysis of literature related to the hybrid methods involving hydrodynamic cavitation has been presented along with recommendations for the selection of important operating conditions for the HC operated individually and in combination with oxidation processes based on hydrogen peroxide (HO), ozone (O) and persulphate (KPS). Subsequently, the treatment of real industrial effluent has also been investigated in details using HC alone and in combined mode with other oxidation processes focusing on the main objective of COD reduction. The reduction in the COD achieved using individual treatment of HC under the optimized conditions of inlet pressure as 4 bar and pH as 4 was only 7.9%. The application of different hybrid approaches based on HC such as HC + HO, HC + O, HC + KPS and HC + HO + O established higher COD reduction as compared to only HC. The maximum extent of COD reduction as 60.8% was achieved using HC + HO + O combination whereas, relatively lower extent of COD was achieved for operations of HC + HO, HC + O and HC + KPS with the actual COD reduction being 40.3%, 38.7% and 8.5% respectively. It was also observed that 30.4%, 28.2%, 15.6%, and 4.7% of TOC reduction was obtained for the combined process of HC + HO + O, HC + HO, HC + O, and HC + KPS respectively. Based on the kinetic study, it was established that the degradation fitted the first order kinetics for all the approaches. The combined processes of HC with oxidants were also compared with ultrasound reactors (both individual and combined operation) in terms of COD reduction, cavitational yield calculations, and treatment cost. HC reactors were established to be more energy efficient and also yielded treatment costs significantly lower than ultrasonic reactors.
在本研究中，单独运行的水力空化（HC）以及与化学氧化剂联合使用的水力空化已被用于处理从当地一家工厂获得的实际工业废水。首先，介绍了与涉及水力空化的混合方法相关的文献分析，并就单独运行以及与基于过氧化氢（HO）、臭氧（O）和过硫酸盐（KPS）的氧化过程联合运行的水力空化选择重要操作条件提出了建议。随后，还详细研究了单独使用水力空化以及与其他氧化过程联合使用对实际工业废水的处理情况，重点是降低化学需氧量（COD）这一主要目标。在入口压力为4巴、pH值为4的优化条件下，单独使用水力空化处理时，COD的降低率仅为7.9%。与仅使用水力空化相比，基于水力空化的不同混合方法，如HC + HO、HC + O、HC + KPS和HC + HO + O，实现了更高的COD降低率。使用HC + HO + O组合时，COD的最大降低率达到60.8%，而对于HC + HO、HC + O和HC + KPS操作，COD的降低率相对较低，实际降低率分别为40.3%、38.7%和8.5%。还观察到，HC + HO + O、HC + HO、HC + O和HC + KPS联合过程的总有机碳（TOC）降低率分别为30.4%、28.2%、15.6%和4.7%。基于动力学研究，确定所有方法的降解均符合一级动力学。在COD降低率、空化产率计算和处理成本方面，还将水力空化与氧化剂的联合过程与超声反应器（单独和联合运行）进行了比较。结果表明，水力空化反应器更节能，处理成本也显著低于超声反应器。
