| Abstract: | Abstract A treatment method of liming effluent of a tannery is tested using hybrid membrane separation processes. The effluent after gravity settling and alum coagulation is subjected to ultrafiltration followed by nanofiltration. The optimum alum dose is obtained by analyzing the effluent using various concentrations of alum. The membrane separation processes are conducted in a continuous cross flow mode. The effects of operating conditions e.g., transmembrane pressure difference, and cross flow velocity (Reynolds number) on the permeate flux are analyzed. Effects of change in hydrodynamic conditions in various flow regimes, e.g., laminar, laminar with turbulent promoter, and turbulent flow on flux improvement have been studied. A resistance‐in‐series model for flux decline during the filtration process is proposed. COD, BOD, TDS, TS, pH, Ca2+ concentration, Cl? concentration and conductivity are measured before and after each operation. The potential of the dried sludge as organic fertilizer is also explored. |
