Transferability of Optimised Coagulation–flocculation Conditions from Synthetic Solutions to Real Tannery Wastewater: A Case Study from Adjamé, Côte d’Ivoire

Abstract

Textile industry wastewater poses environmental concerns due to its complex composition, including organic dyes and low biodegradability, necessitating treatment before discharge. Coagulation/flocculation is an effective pretreatment technique, but its efficiency in real effluents can be affected by the complex matrix, requiring optimisation and validation. This study investigates the transferability of optimal coagulation–flocculation conditions for Remazol Black removal from synthetic solutions to real textile wastewater. Effluents collected from two artisanal tanneries in Adjamé (Abidjan, Côte d’Ivoire) were characterised by physico-chemical parameters, organic pollution indicators, nitrogen compounds, sulfates and dye concentration. In situ measurements of pH, temperature, electrical conductivity and salinity were carried out using a calibrated multiparameter meter (WTW pH/Cond 340i) equipped with combined electrodes for pH/potential and conductivity/salinity. The wastewater exhibited acidic pH, high chemical and biochemical oxygen demand, and elevated salt and nutrient levels, exceeding discharge standards. Principal component analysis showed strong correlations among temperature, pH, conductivity, turbidity, ammonium and salinity. Application of the optimised conditions (38.77 mg·L⁻¹ Remazol Black, 41.3 g·L⁻¹ Al³⁺ and 1.7 mL coagulant) achieved average removal efficiencies of 87.43 % and 76.66 % for the two tanneries. Despite lower performance than in synthetic media, coagulation–flocculation proved effective for real effluents, emphasising its potential for textile wastewater treatment.