Ibrahim Umar Salihi

Adsorption of Lead ions onto Activated Carbon derived from Sugarcane bagasse

In this study, activated carbon was developed from sugarcane bagasse and its effectiveness in adsorbing lead (Pb2+) ions from synthetic aqueous solution was examined. Sugarcane bagasse activated carbon (SCBA) was developed in a tube furnace at a temperature of 900 °C, a heating rate of 10 °C/min, residence time of 3 hours, and at a nitrogen flow rate of 100 mL/min. Batch adsorption experiments were carried out to investigate the effects of pH and SCBA dosages on the adsorption process. The batch adsorption test showed that extent of Pb2+ adsorption by SCBA was dependent upon pH and SCBA dosage. The optimum pH for Pb2+ adsorption was found to be at pH 5.0. Maximum Pb2+ removal efficiency obtained from the batch studies was 87.3 % at SCBA dosage of 10 g/L. Equilibrium adsorption data was described by Langmuir model with a coefficient of determination (R2) of 0.9508. Maximum adsorption capacity according to Langmuir model was evaluated to be 23.4 mg/g. The adsorption capacity of the SCBA was compared with that of other plant-based adsorbents. SCBA is an effective adsorbent for the removal of Pb2+ from aqueous solution.

Removal of methylene blue from dye effluent using ageratum conyzoide leaf powder (ACLP)

Methylene blue (MB), a common environmental pollutant discharged from dye effluents were removed from synthetic effluents in this study using ageratum conyzoide leaf powder. Effects of operating parameters such as pH, initial Methylene blue concentration, adsorbent weight and contact time were examined on methylene blue removal whereas stirring speed was constant at 100 rpm. Results show that low pH (3-4) had more Methylene blue removal than high pH. Methylene blue removal decreased when initial concentration was increased but increased when adsorbent weight was increased. Removal of Methylene blue by Ageratum conyzoide leaf powder was rapid and significantly above 80% in all initial concentrations examined. At optimum conditions of pH 3, 20 minutes contact time and adsorbent weight of 60 mg for Methylene blue initial concentration of 20 mg/L, 40 mg/L and 60 mg/L, Methylene blue removal of 84.7%, 83.9% and 81.2% were obtained respectively. Results suggest that Ageratum conyzoide leaf powder could be poten...

Sorption of Copper and Zinc from Aqueous Solutions by Microwave Incinerated Sugarcane Bagasse Ash (MISCBA)

Industrial wastewater containing toxic pollutants such as heavy metals tends to contaminate the environment once it is release without proper treatment. Heavy metals are toxic to both human and other living organisms. It is necessary to treat industrial wastewater polluted with heavy metals prior to its discharge into the receiving environment. In this study, low cost adsorbent was generated from sugarcane bagasse through incineration. The prepared adsorbent “microwave incinerated sugarcane bagasse ash” (MISCBA) was used in removing copper and zinc from aqueous solution. Parameters of importance such as pH, contact time and adsorbent dosages are studied to investigate their effects on the adsorption of copper and zinc. Maximum adsorption was observed at pH 6.0, contact time of 180 minutes and adsorbent dosage of 10 g/L. Zinc removal follows Langmuir isotherm model with correlation coefficient of 0.9291. Copper adsorption follows both Langmuir and Freundlich isotherm model with correlation coefficient of 0.9181 and 0.9742, respectively. Removal capacities of 38.4 mg/g and 20.4 mg/g were obtained for copper and zinc, respectively. Application of MISCBA as low - cost adsorbent have shown significant outcome in removal of copper and zinc from aqueous solution.

Evaluation of Leachate Characteristics from Different Leachate Ponds in a Semi-Aerobic Landfill

In this study, the performance of a semi-aerobic landfill was monitored through the analysis of leachate composition collected from different leachate ponds; collection pump (CP), equalization pond (EQ) and aerated pond (AP). The landfill site is located in the tropical environment of the central region of Malaysia. Twenty parameters were analyzed and the average values of the parameters for leachate at the CP, EQ and AP, which include; pH (8.24, 8.00 and 8.73), total kjeldahl nitrogen (3987.25, 8744.6, 1927.31 TKN-N), ammonia-N (3726, 3800, 1560 mg/L NH3-N), nitrate (26.7, 33.3, 25 mg/L NO3-N), total phosphorus (0.85, 0.78, 0.92 mg/L PO43-), BOD5 (305, 311.3, 201 mg/L), COD (16100, 14587, 12780 mg/L), BOD5/COD (0.019, 0.021, 0.016), turbidity (405, 735, 940 NTU), colour (3991, 4122, 3412 Pt Co), TSS (109.3, 58, 50.7 mg/L), EC (32.8, 21.9, 37.0 mS/cm) and TDS (21.98, 14.7, 24.8 mg/L) were recorded appropriately. The results realized from the analysis of the three ponds, were compared with previously published data and also the standards specified by the Malaysia Environmental Quality Act 1974. The obtained results indicate that the leachate from the aerated pond could remove some of the pollutants and was more stabilized when compared with the leachate from the pump and equalization ponds. It is also found that the aeration process in aerated pond could enhance the reduction of pollutants in the leachate. The measured leachates would require appropriate treatment methods in order to reduce the pollutants to meet the discharge standard before releasing them into water courses.

Copper Removal with Biologcal Treatment Aided with Modified Adsorbents

The performance of a biological system was evaluated for copper removal with and without the addition of an adsorbent to the aeration compartment. Three different reactors were employed in this study. The first reactor consist of biomass alone and was used as a control reactor (CR). The second reactor consist of biomass and microwave incinerated rice husk ash (MIRHA) whereas the third reactor consist of biomass and hybrid adsorbent (HA), which is a mixture of MIRHA and groundwater treatment plant sludge (GWTPS). The reactors were operated at solid retention time (SRT) of 30 days and hydraulic retention time (HRT) of 19.8 hours. The experiment was conducted in 8 different phases consisting of various copper concentrations coming from the influent source. The first and second phase were acclimation period during which copper was not added to the influent wastewater. From the third to the eight phase, copper was fed to the reactors at different concentrations. Reactor performance was monitored every two days. Results show that copper toxicity was significant for the control reactor from phase from phase 5 to phase 8 with effluent concentration between 0.34 – 2.62 mg/L. Copper removal was significant for both MIRHA and HA reactor. Effluent copper concentration in the MIRHA reactor was 2.04 mg/L and 1.09 mg/L for HA reactor at phase 8 (copper concentration 15 mg/L). Addition of the adsorbents (MIRHA and HA) enhanced the biomass tolerance towards copper toxicity at high concentration and improved copper removal efficiency. This study, therefore demonstrates that low cost non-conventional adsorbents could be utilized as support materials to enhance biomass tolerance towards heavy metal toxicity.

Determination of optimum range for hexavalent chromium Cr(VI) removal using ageratum conyzoide leaf powder (ACLP)

The optimum range of process parameters for hexavalent chromium Cr(VI) removal were determined in a batch study using Ageratum conyzoide leaf powder (ACLP) as adsorbent. The process parameters were varied in the range 2-10 for Initial solution pH, 135-400 mg/L for initial concentration, 30-180 minutes for contact time and 0.1-0.6 g for adsorbent weight. Solution pH was adjusted using 0.1 M H2S04 and NaOH respectively. Results show that initial solution pH was vital for Cr(VI) removal. At low initial solution pH (pH 2), Cr(VI) removal was high but decreased when the solution was increased from pH 4 to 10. Cr(VI) removal decreased when initial solution concentration was increased and increased when contact time and adsorbent weight was increased. At initial solution concentration of 135 mg/L, residual Cr (VI) concentration was about 53.7 mg/L (61 % removal efficiency) at optimum range of pH 2, adsorbent weight 0.3 g and contact time 120 minutes. Ageratum conyzoide leaf powder (ACLP) could be a potential ads...