Adsorption evaluation of Rhodamine WT, lithium and chloride in batch reactors inoculated with anaerobic sludge

Abstract

The aim of this study is to evaluate trace’s mass adsorptive property of anaerobic sludge in batch reactors. Three types of tracers were prepared, i.e. Rhodamine WT (RWT), lithium and chlorine. 4 reactors of one liter were inoculated with 200 mL (20%) of anaerobic granular sludge from a local brewery and fed with municipal wastewater (ARM) from Maracaibo city. The systems were considered stable when the biogas production was between 35.5 and 40.5 mL/d. At that moment the tracers were added to either reactor. The alkalinity were measured from 360-430 mgCaCO3/L, suffi cient to maintain the pH in the range close to neutral (6.41 to 6.62). The results show that RWT tracer ́s mass was favorable for adsorption and according to Langmuir adsorption model it increased with increasing concentration. Adsorption (qe) varied from 1.777 E-5 - 3.462 E-5 mgWRT/gsludge. No adsorption was observed with lithium and chlorine.

Keywords

• adsorption
• Langmuir
• Freundlich
• tracer