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The ability of Turbinaria ornata seaweed derived biochar (TOB) to remove arsenate ions from polluted solutions in batch and column trials has been investigated. The biochar, produced at 300 °C and 120 min through pyrolysis, exhibited maximum arsenate sorption capacity at pH 4. Batch sorption isotherm was described with different models (Freundlich, Langmuir and Sips) and the Sips model best described the experimentally derived isotherm with high correlation coefficient and low percentage error values. The maximum arsenate sorptional capacity calculated using the Langmuir model was estimated to be 0.124 mmol/g (at pH 4; 2 g/L biochar dosage and 0.5 mmol/L initial arsenate concentration). For elution trials, 0.01 M NaOH performed well to desorb arsenate from arsenate‐bounded TOB with elution efficiency greater than 99.6% with no significant damage to TOB. The capability of TOB to sorb arsenate continuously was examined in a packed column. The continuous trials were mainly performed to evaluate the impact of influential column parameters including bed height, initial arsenate concentration and flow rate. The arsenate sorptional capacity declined with improvement in flow rate, whereas enhanced with increment in bed depth and initial arsenate concentration values. Regeneration of exhausted TOB was possible with 0.01 M NaOH. After three sorption‐elution cycles it was determined that TOB exhibited superior sorption capacities and percentage removal efficiencies.

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The current research was performed to examine the effects of date seed‐derived biochar (DSDB) for remediation of hazardous metal ions (lead (II) and cadmium (II)) from binary and single systems. The maximum sorption uptakes of 0.484 and 0.798 mmol/g were recorded for lead (II) and cadmium (II) ions, respectively, at an equilibrium pH of 4.5. For both metal ions, DSDB produced quick kinetic uptake rates with most of the removal process (90%) completed within 60 mins. Different types of models were applied to depict lead (II) and cadmium (II) isotherms (Toth, Redlich–Peterson, Freundlich, and Langmuir) and kinetics (pseudo‐first and ‐second order) data. Desorption method was attempted and DSDB was reutilized in five consecutive cycles successfully using 0.01 M HCl as elutant. During binary sorption, decreased uptake of cadmium (II) by DSDB was observed due to the presence of lead (II). In comparison to single solute system, the uptake of cadmium (II) was reduced to 26.5% while only 1.2% reduction for lead (II) was observed. While comparing the two multi‐component isotherm models (Langmuir and Freundlich), the multicomponent Langmuir model performed well in describing the cadmium (II)+lead (II) binary isotherm with high accuracy.