The discharged of lead and cadmium above maximum permissible limits into surface water and environment without any pre-treatment methods has caused severe heath challenges to humanity. In other to minimize the reoccurrence, this research aim to ascertain biosorption capacity of bamboo stem biomass to remove lead and cadmium from aqueous solution. Batch experiment and data evaluation under optimum removal conditions (such as pH, contact time, temperature, biosorbent dosage, initial heavy metal concentration) were determined. Maximum optimum removal was observed for both metal ions at pH 5, 90 min contact time, 298K temperature with 50 ppm of initial concentration for 95.92 and 80.98% removal for lead and cadmium. Lead revealed better results at all concentrations for bamboo stem biomass with increase in percentage removal as concentration of heavy metal increases. Kinetics and isotherms models were applied and this shows that kinetic models are described and fitted well with pseudo-second order reaction while adsorption isotherm model supported Freundlich model with high R 2 values. Thermodynamically, biosorption of lead and cadmium was exothermic and lead was greater than cadmium in the order of spontaneity and entropy. From these results, it can be concluded that bamboo stem biomass has been shown to be productive in removal of heavy metals from aqueous solution.

The removal of heavy metals from our environment especially industrial effluents is now shifting from the use of conventional adsorbents to the use of chemical precipitation. The presence of heavy metals in the environment is a major concern because of their toxicity, bioaccumulating tendency, and threat to human life and the environment. The main objective of this research is to study the effectiveness of the combination of hydrogen peroxide and activated bentonite clay in the removal of heavy metal ions from pharmaceutical industrial effluent. About 13.790 mg/l of Fe, 1.650 mg/l of Zn and 2.000 mg/l of Ni were detected in the digested sample and batch removal of heavy metals such as Fe, Zn and Ni from industrial wastewater effluent under different experimental conditions using hydrogen peroxide as precipitating agent in combination with activated bentonite clay as adsorbent. Appreciable differences in the level of heavy metals concentration were observed based on pH effect. The result shows higher effectiveness relatives to other treatments formulated for the effluent treatment such as Alum precipitation effect, effect of hydrogen peroxide concentration dose, contact time effect and temperature effect. Removal of heavy metals in effluent was optimum at pH 10 for zinc (Zn) and nickel (Ni) and at pH 8 for iron (Fe), at temperature of 50°C, 0.75% hydrogen peroxide concentration dose and 100 mins holding time, reducing the amounts from 13.790 to 1.436 mg/l of Fe, while 1.650 to 0.127 mg/l of Zn and 2.000 to 0.115 mg/l of Ni respectively. The percentage differences in concentration for the heavy metals removal in industrial wastewater are as follows: Fe (89.58%), Zn (92.30%) and Ni (94.22%). The result showed high level of Zn and Ni generated from this pharmaceutical industry is above 1 mg/l FEPA and WHO standard but only Fe showed low level concentration compared to 20 mg/l FEPA and WHO standard in this study. This study reveals the need for enforcing adequate effluent treatment methods before their discharge to surface water to reduce their potential environmental hazards.

Natural bentonite clay (NBC) was activated using nitric acid (HNO3). Characterization techniques including FTIR, SEM, XRD and BET were employed to examine the morphology of NBC and ABC (activated bentonite clay) sorbents. Comparative application of ABC and NBC to remove heavy metals (Fe2+, Zn2+, Ni2+) from pharmaceutical effluents was investigated under various experimental conditions. The maximum proportional removal by ABC was 88.90, 81.80 and 75.50% at pH 8, and 63.90, 59.60, 58.70% at pH 10 for NBC, both for Zn2+, Fe2+ and Ni2+ respectively. The Freundlich multilayer adsorption model and pseudo-second-order kinetics best fit the experimental data, suggesting the formation of multiple adsorption layers via strong ionic and electrostatic interactions. Heavy metals adsorption is more favorable with ABC than NBC, due to the availability of more sorption sites and a larger specific surface. The thermodynamic parameters (ΔH°, ΔS°, and ΔG°) revealed that the adsorption is endothermic and spontaneous in nature for both ABC and NBC.