In this research, the optimization and predictive modeling of gravimetric corrosion characteristics of Irvingia gabonensis leaf extracts (IGLE) as an anti-corrosion inhibitor of mild steel in hydrochloric acid were investigated. Design expert software version 11 were used to analyze the corrosion inhibition-related process characteristics, such as inhibition efficiency, corrosion rate, and weight loss, and their relationships. An effort were made to obtain the optimal conditions for these corrosion inhibition-related process characteristics. Weight loss measurement and design methodology were used for the evaluation of the inhibition efficiency of IGLE for mild steel in HCl. The corrosion inhibition process variables were optimized and predictive regression models were developed using Box-Behnken tool of the Response Surface Methodology (RSM). The findings showed that there were a good fit between the model predictions and the experimental results. The quadratic models developed were significant with P value less than 0.05.  The research established an inhibition efficiency of 88.9%, a corrosion rate of 0.143mm/yr, and a weight loss of 0.02 g, which were obtained at the optimum conditions of an extract concentration of 0.6 g/L, an immersion time of 16 hrs, and a temperature of 298K.Therefore, the models were considered ideal for prediction with a confidence level of 95%, and the optimal combination is suitable for the corrosion inhibition process design. Hence these models can be recommended for applications such as oil well acidizing and pickling pipelines.

A mini thermoelectric Peltier Refrigerator was designed and built in this study. The Peltier thermoelectric cell was attached in between an external heat sink and internal radiator that acted to remove heat from the internal space of refrigeration box to be conducted and removed to the ambient. To ensure the success of this study several criterions are to be satisfied such as portability, size and cost of the system. The design of the system is based on the principles of thermoelectric module (i.e. Peltier effect) to create a hot side and a cold side. Thermoelectric refrigeration work on the principle of see beck effect in which the voltage is applied between two different combinations of metal and due to effect of see beck the cooling and heating phenomena happens which can be used accordingly for different purposes. The cold side of the thermoelectric module is used for refrigeration purposes; provide cooling to the vaccine chamber. On the other hand, the heat from the hot side of the module is rejected to the surroundings with the help of a heat sink and fan assembly.

Green chemistry has become trending recently, and the discovery of environmentally friendly catalysts is mandatory. Activated carbons (ACs) are one of the most environmentally friendly yet cheap materials that have the potential for catalyst application. Three commercially available ACs from Pancasari, Norit, and Chemical Supply were used as metal-free catalysts for advanced oxidation process (AOP) phenol removal in water in the presence of oxidants peroxydisulfate (PDS), and hydrogen peroxide (H₂O₂₎. It was found that ACs were effective to be used as catalysts for activating those oxidants to oxidize phenol in AOP reactions. In this study, the surface area of the catalyst significantly improved the phenol removal efficiency. ACs Pancasari (ACP) with the highest surface area has the best degradation performance of phenol removal with up to 99% removal efficiency in 60 minutes under the condition of [phenol] = 30 mg L^-1, [ACP] = 0.2 g L^-1, [PDS] = 3.3 mmol L^-1, and T = 25^oC. it was also found that the degradation process was significantly influenced by reaction temperature. Nevertheless, in this study, ACs display the potential as catalysts in the AOP process for wastewater treatments.

The generation of oilseed wastewater is a matter of worry due to the presence of impurities that could have effects on ecosystems and human health. This study explores the potential use of rice husk chemically modified with 1M NaOH as an adsorbent to treat wastewater from Sunseed Nigeria Limited in Zaria, Nigeria. The adsorbent was characterized employing Fourier transform infrared spectroscopy (FTIR), which revealed the presence of carboxylic acid, alkanes, alkynes, and amide. Correspondingly, batch adsorption tests were conducted for a fixed period of 1 hour by using dosages of 2, 4, 8, 16, and 20 g. The findings indicated that the turbidity, BOD, and COD had the highest percentage of removal at dosages of 2 g, 20 g, and 2 g, respectively, with removal percentages of 81.48 %, 81.3 %, and 85 %. Also, lead and cadmium had removal percentages of 17.5% and 87.6%, respectively, at a dosage of 20 g. Furthermore, the Langmuir isotherm offered a greater fit for turbidity and total solids, with R² values of 0.5355 and 0.8870, respectively, with the resultant absorption capacities of 0.0074 mg/g and 0.0249 mg/g. Similarly, the Freundlich isotherm described the BOD and COD well, with R² of 0.6097 and 0.9678, respectively, and relative adsorption capacities of 1.3104 mg/g and 4.808*10⁶ mg/g. Therefore, it can be concluded that the rice husk adsorbent has demonstrated effectiveness in removing certain physicochemical pollutants from oilseed industrial wastewater.

Despite the measures taken by most countries, lead pollution still poses an environmental and health risk to humans, especially children. Therefore, the current study aims to evaluate lead in the air and its impact on children's health. Lead samples from the air and children's urine were collected from three different areas within Kerbala Governorate: the urban city center residential areas, and rural areas as a reference area for comparison.  A suspended dust collector was used to collect lead samples, and then the lead concentration was measured using an atomic spectrometer after digesting them with acids.  The results of the study showed that the highest concentration of lead was in the center of the urban area (3.150 ?g/m³) and its mean concentration in the air was 1.703 (?g/m³), which is higher than the US Environmental Protection Agency limits, with statistically significant differences between the study areas p < 0.01. The mean concentration of lead in children's urine was 0.622 (?g/dL) with statistically significant differences between the areas p < 0.01. Pearson's correlation coefficient indicated a significant positive correlation between the concentration of lead in the air and children's urine (r = 0.651; p < 0.05). This means that high lead concentrations in children's urine are due to lead air pollution and are an indicator of lead pollution in the environment and warn of potential risks to children's health. Therefore, the study recommends reducing lead emission sources and conducting periodic examinations.