In the present study, coagulation followed by cavitation was studied as a pretreatment tool for tannery waste effluent (TWE) with the aim of reducing its COD, TOC, TSS etc. and enhancing its biodegradability to make it suitable for anaerobic digestion. Initially, coagulation was applied to TWE using alum as a coagulant. The residual pH of treated effluent was found to be around pH of 4.5 where maximum COD and TSS reduction was achieved. In order to enhance the efficiency of pretreatment process, coagulated tannery waste effluent (CTWE) was further subjected to hydrodynamic cavitation (HC) and ultrasonication (US). In case of HC, effect of process parameters such as inlet pressure and dilution on the treatment of CTWE was initially investigated. Lower operating pressure (5 bar) was more favorable for the treatment of CTWE using HC in order to enhance the biodegradability index (BI) from 0.14 to 0.57 in 120 min. The CTWE samples when subjected to 50% dilution, HC pretreatment exhibited higher percentage and quantum reduction in TOC and COD. On the other hand, pretreatment of TWE using coagulation followed by US demonstrated that BI of effluent was enhanced from 0.10 to 0.41 in 150 min. Energy efficiency evaluation for all processes at their optimized conditions was done based on the actual amount of COD reduced per unit energy delivered to the system. Coagulation followed by HC for the pretreatment of TWE was found to be six times more energy efficient as compared to coagulation followed by US.

在本研究中，研究了混凝后空化作为制革废水的一种预处理工具，目的是减少其COD，TOC，TSS等并增强其生物降解性，使其适合厌氧消化。最初，使用明矾作为凝结剂对TWE进行凝结。发现处理后的废水的残留pH值约为4.5，可实现最大的COD和TSS降低。为了提高预处理过程的效率，对凝结的制革厂废液（CTWE）进一步进行了水力空化（HC）和超声处理（US）。对于HC，最初研究了工艺参数（例如入口压力和稀释度）对CTWE处理的影响。较低的工作压力（5 bar）更适合使用HC处理CTWE，以在120分钟内将生物降解指数（BI）从0.14提高到0.57。将CTWE样品进行50％稀释后，HC预处理的TOC和COD百分比更高，并且量子减少。另一方面，先用凝结法再用US预处理TWE，证明出水的BI在150分钟内从0.10提高到0.41。所有过程在其优化条件下的能效评估都是基于传递给系统的每单位能量减少的实际COD量进行的。发现混凝后加HC进行TWE的预处理，其能量效率是混凝后US的六倍。将CTWE样品进行50％稀释后，HC预处理的TOC和COD百分比更高，并且量子减少。另一方面，先用凝结法再用US预处理TWE，证明出水的BI在150分钟内从0.10提高到0.41。所有过程在其优化条件下的能效评估都是基于传递给系统的每单位能量减少的实际COD量进行的。发现混凝后加HC进行TWE的预处理，其能量效率是混凝后US的六倍。将CTWE样品进行50％稀释后，HC预处理的TOC和COD百分比更高，并且量子减少。另一方面，先用凝结法再用US预处理TWE，证明出水的BI在150分钟内从0.10提高到0.41。所有过程在其优化条件下的能效评估都是基于传递给系统的每单位能量减少的实际COD量进行的。发现混凝后加HC进行TWE的预处理，其能量效率是混凝后US的六倍。所有过程在其优化条件下的能效评估都是基于传递给系统的每单位能量减少的实际COD量进行的。发现混凝后加HC进行TWE的预处理，其能量效率是混凝后US的六倍。所有过程在其优化条件下的能效评估都是基于传递给系统的每单位能量减少的实际COD量进行的。发现混凝后加HC进行TWE的预处理，其能量效率是混凝后US的六倍。