Processing of Total Chromium and Organic Compound in Tannery Wastewater Using Eggshell and Zeolite Sand

Tannery industry was generating wastewater from its production activities. This wastewater contains chromium metal ions as a hazardous and toxic compound for human health. In this study, treating of chromium metal ions and organic compounds in the tannery wastewater has been studied. The wastewater processing was used by a combination of precipitation and adsorption methods. Precipitation uses Ca(OH)2 as a natural coagulant that obtained from chicken eggshell after calcined at high temperature. Adsorption process uses zeolite sand that activated with BaCl2. Precipitation performed at pH 11, then followed with adsorption optimized through variation of adsorbent weight and contact time. From the results shows that optimum condition due to the combination of precipitation and adsorption was occurred at pH 11, adsorbent weight 0.5 g and contact time 30 minutes where the methods can reducing total chromium ions and organic compounds up to 99% as elimination level. The content of the wastewater sample after processing reducing total chromium up to 0.043 mg/l, BOD5 up to 2.56 mg/l, COD up to 4.3504 mg/l and TSS up to 3.00 mg/l. The results explain that the wastewater pollutant referenced the standard quality of tannery industry activities have been fulfilled, so that secure to dispose into the environment.