The presence of heavy metals in wastewater has raised concern in developing countries because of their impact on human health and environmental ecology. Therefore, this study aims to remove cadmium and lead ions from wastewater using natural Pterocarpus santalinoides fruit through the adsorption method. The Box-Behnken design (BBD) of the response surface methodology (RSM) method was adopted to optimize the process variables such as contact time (20-100 min), adsorbent dose (0.1-0.5 g), initial metal ion concentration (10-50 mg/l), and temperature (30-70 °C). The ANOVA results clearly indicate that the linear model was not sufficient to best predict the removal performance of cadmium (R2 = 0.4009) and lead (R2 = 6353). The optimum conditions for the maximum Cd (94.81%) and Pb (89.23 %) adsorption onto the adsorbent were achieved at contact time (42.16 min), adsorbent dose (0.25 g), initial metal ion concentration (21.52 mg/l), and temperature (37.00 °C). According to the findings of the present work, Pterocarpus santalinoides shows to be a potential eco-friendly and cheap adsorbent for the removal of Cd and Pb from aqueous solutions. The BBD-RSM actual and predicted values of the Cd and Pb ions response show non-significant correlation, suggesting poor agreement between the two, revealing that the BBD-RSM model applied is not effective for the relationship between the four parameters examined in the Cd and Pb ions removal process.

The present study was carried out on Safari Park, Lahore, Punjab, Pakistan. The sampling was carried out randomly in different seasons from different water bodies of the park especially from Lake. Thirty-seven species belonging to six genera i.e., Pediastrum (4 species & 11% abundance), Trachelomonas (4 species & 11% abundance), Euglena (11 species & 30% abundance), Phacus (12 species & 32% abundance), Lepocinclis (1 species & 3% abundance) and (5 species & 13% abundance). All genera belong to kingdom Protista, two phyla i.e., Volvocophycota and Euglenophycota, two classes i.e., Volvocophyceae & Euglenophyceae, two orders chlorocoocales and Euglenales and three families i.e., Hydrodictyaceae, Euglenaceae and Naviculaceae.

The global climate continues to deteriorate, resulting in excessive carbon emissions, heavy metal pollution possesses serious threats to human life and modern civilization. The concentration of Zn, Fe, Cr, Pb, Cu and Cd in soil and rice grown in two locations (A and B) AROUND Edozhigi river were determined using standard methods og analysis. Results obtained for location A, indicate high concentration of Zn 9.75±0.55, 9.61±0.54, 1.03±0.58 and 1.69±0.66 mg/kg in soil, root, stem and seed of rice plant respectively. The order of Zn concentration of Zn metal in location B is 2.07±0.55 (soil) > 1.70±0.54 (root) > 1.67±0.58 (stem) > 1.27±0.66 (seed). Concentration of Fe (mg/kg) in soil (25.50±0.00) and root (26.32±0.00) from location B were significantly higher than those of stem (8.46±0.00 mg/kg) and seed (6.98±0.00 mg/kg) respectively. Concentration of Cu (mg/kg) in soil, root, stem and seed from location A and B were between 0.00±0.00 - 0.03±0.40 mg/kg respectively. The low concentration of these metals in soil around Edozhigi river makes the soil fit for growing crops.

This study investigates the concentrations of heavy metals and physicochemical properties of water, sediment, and African catfish (Clarias gariepinus) from earthen and concrete ponds used for aquaculture in Port Harcourt, Rivers State, Nigeria. Physicochemical analysis showed that water from earthen ponds had a pH of 5.60-7.52, salinity of 0.06-1.03 ppt, conductivity of 170-1671 μScm⁻¹, and turbidity of 38.71-163 NTU. In contrast, concrete ponds had a pH of 6.75-7.56, salinity of 0.18-0.71 ppt, and conductivity of 325-1442 μScm⁻¹, indicating differences in water quality. Water samples from earthen ponds exhibited cadmium (Cd) levels ranging from 0.013 to 0.187 mg/kg, lead (Pb) from 0.649 to 0.651 mg/kg, zinc (Zn) from 0.052 to 0.80 mg/kg, copper (Cu) from 0.009 to 0.158 mg/kg, and iron (Fe) from 1.198 to 4.112 mg/kg. In contrast, Concrete ponds showed Cd levels from -0.014 to 0.008 mg/kg, Pb from -0.0154 to 1.518 mg/kg, and Zn from 0.072 to 3.038 mg/kg. In earthen pond sediment, Cd ranged from 0.059 to 0.326 mg/kg and Pb from 0.505 to 1.160 mg/kg, exceeding permissible limits, especially at sites B and C, indicating contamination. Fish from earthen ponds had high heavy metal levels, with Cd from 0.175 to 22.433 mg/kg and Pb from 1.121 to 22.613 mg/kg, showing significant bioaccumulation. Conversely, concrete ponds had lower contamination, with Cd in sediment from 0.250 to 0.412 mg/kg and Pb in fish from 0.693 to 5.376 mg/kg, closer to safe thresholds. The results indicate significant contamination differences between pond types, with earthen ponds exhibiting higher heavy metal levels due to soil composition and exposure. In contrast, concrete ponds, which minimize soil-water interaction, showed lower metal presence in fish, highlighting a safer aquaculture environment. These findings stress the importance of continuous monitoring of earthen ponds and improved management practices to ensure consumer safety and sustainable aquaculture.