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Sanitary landfills are important means of disposing municipal solid waste in developing countries. However, these landfills are associated with the generation of leachate, which if untreated may pose severe public health risk and may damage the ecosystem in the long term. In this study, cockle shells were explored as an adsorbent media for the treatment of a stabilized landfill leachate. The optimum shaking speed, pH, and dosage for chemical oxygen demand (COD) parameter removal were investigated using the adsorbent media of particle sizes ranging from 2.00 mm to 3.35 mm. Leachate characteristics were then determined. Results indicated that leachate is non-biodegradable with high concentrations of COD (1763 mg/L), ammonia nitrogen (573 mg/L), and biochemical oxygen demand/COD (0.09). The optimum conditions for shaking were determined at 150 rpm according to the adsorption of COD by the media. Optimum pH and dosage was 5.5 and 35 g/L, respectively. The adsorption isotherms indicated that Langmuir isotherm is better fitted than Freundlich isotherm.

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Renewable and alternative fuels such as ethanol find application in several combustion devices. Fundamental characteristics of these fuels in terms of ignition and burning rate are to be understood in order to use them in these applications. In this study, a numerical analysis of auto ignition characteristics of ethanol is presented. Opposed flow configuration, in which fuel and nitrogen emerges from the bottom duct and hot air flows down from the top duct, has been employed. Commercial CFD software FLUENT is used in the simulations. Global single step mechanism is used to model kinetics. For various mass fractions of fuel, the air temperature at which auto-ignition occurs has been recorded. The numerical results are compared with the experimental data available in literature.

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Landfills generate leachate that contains elevated concentration of contaminants and is hazardous to human health and the ecosystem. In this study, the mixture of granular feldspar and cockle shells was investigated for remediation of COD and ammonia from landfill leachate. All adsorbent media were sieved to a particle size between 2.00 and 3.35 mm. The results revealed that the optimum mixing ratio of feldspar and cockle shells was 20:20, shaking speed was 150 rpm, pH level was 6, shaking time was 120 min, and dosage was 30 g. The adsorption isotherm analysis reveals that the Langmuir isotherm yielded the best fit to experimental data as compared to the Freundlich isotherm. The media produce encouraging results and can potentially be used as a good and sustainable adsorbent.

Plant waste such as Delonix Regia Pods (DRP) have the potential to be used as adsorbents. A study of lignocellulose delonix regia pods was carried to assess ammoniacal nitrogen removal from natural rubber wastewater. Sample wastewater was taken from the rubber processing industry and characterization was carried out. Outcomes from the analysis shows that the ammoniacal nitrogen concentration was 66 mg/L and higher than the recommended wastewater discharge standards. Batch experiments were conducted on the effect of dose, pH, shaking speed and contact time parameters for optimum condition. The results revealed that the optimal dosage, pH, shaking speed and contact time is 4.5 g, pH 8, 150 rpm and 120 minutes with ammoniacal nitrogen removal efficiency of 74.3 % and the adsorption capacity of 1.22 mg/g. Pseudo second order kinetic model was found to fit the data better and the R 2 obtained was 0.9992. From the study, it can be concluded that the media can be used for the removal of ammoniacal nitrogen in natural rubber wastewater and subsequently reduce environmental pollution. Hence, it can be sustainable and environmentally friendly.

NH 3-N (Y NH3-N) by using response surface methodology (RSM) via central composite design (CCD). RSM