Biosorption of Cadmium (II) and Chromium (VI) from Aqueous Solution by Chemically Modified Tithonia Diversyfolia Biomass

Staff PublicationThe search for alternative and innovative treatment technologies for the effective removal of heavy metals from aqueous wastes has been a research of concerted effort due to the inherent limitations exhibited by the conventional methods such as less efficiency, sensitive operating conditions, energy requirements and generation of toxic sludge or other waste products. Biosorption, the passive uptake of heavy metals by biomaterials has been studied recently because of its high efficiency and cost effectiveness. Therefore, the biosorption capacity of Tithonia diversyfolia biomass chemically modified with sodium hydroxide for the removal of cadmium and chromium ions from aqueous solution was investigated. The effects of temperature, contact time, initial concentration of metal ions, adsorbent dosage and pH on the biosorption of Cd2+ and Cr6+ ions were assessed. Thermodynamic parameters such as free energy change (ΔG), enthalpy change (ΔH) and entropy change (ΔS) during the biosorption were evaluated. The results showed that the biosorption process of Cd2+ and Cr6+ by chemically modified Tithonia diversyfolia (CMTD) biomass was feasible and exothermic under the studied conditions. The equilibrium process was well described by the Langmuir isotherm model, with a maximum biosorption capacity of 46.75mg/g and 48.00mg/g for Cadmium and Chromium ions, respectively. Kinetic studies indicated that the biosorption of metal ions followed a pseudo-second order equation

Evaluation of Airborne Particulate Matter in Some Selected Cities in Delta State, Nigeria

Air pollution in Nigeria and many other countries all over the world is a big problem of the 21st century caused by globalization and industrialization. Oil exploration in the Niger Delta region, including Delta state, has grossly reduced the quality of air in the region. This research work focused on evaluation of air borne particulate matter in major cities such as Warri, Ughelli, Sapele and Ugbenu in Delta State. This was done to determine their concentrations, impacts of the pollutants, health implications and possible management measures on lives and environment. Particulate matter in air samples were obtained using Casella microDust Pro Aerosol monitoring system and monitored for a period of one year covering both wet and dry seasons. Polyurethane Foam Filter (PUF) gravimetric adapter was used to provide size-selective sampling for PM10 and PM2.5 fractions. The results showed that Total Suspended Particulate (TSP), Particulate Matter 10 (PM10) and Particulate Matter 2.5(PM2.5).  ranged between 1.02 – 12.36 mg/m3 (average 5.03 ± 0.38), 0.17 – 10.5 mg/m3 (average 2.13 ± 0.26) and 0.44 – 6.64 mg/m3 (average 2.17 ± 0.20) respectively; clearly exceeded the regulatory limits of Federal Ministry of environment (FMENV) and National ambient air quality standards (NAAQS) in both seasons. The study also showed that Matrix (Warri), Amukpe (Sapele) and Ekakpamre (Ughelli) recorded the highest concentration of particulates in the three cities studied. Higher values were obtained in the dry season than the wet season. The correlation of meteorological parameters with TSP, PM10 and PM2.5 shows that only temperature had a weak, but significant, correlation while other parameters did not show any correlation with the concentration of the particulates. The low correlation or absence of correlation between the particulates and meteorological parameters suggests that anthropogenic contributions are significant to their concentration in the study areas. This can be attributed to high level of fuel combustion from motor vehicles, power generation and industrial facilities. The pollution could also be due to dusty industries, windblown dust, crushing and grinding operations. Ugbenu, the control location also recorded high level of particulates; this is due to residential fireplace, wood stoves, unsuspended dust from untarred road, bush burning and windblown dust predominant in the area