1,720,982 research outputs found
Ammoniacal Nitrogen removal using flamboyant pods (Delonix Regia) adsorbent for natural rubber wastewater treatment
No full textPlant 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 R2 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
Chitosan beads as an adsorbent for the removal of colour from natural rubber wastewater
No full textNatural rubber processing wastewater contains high concentration of organic compound, colour, nitrogen, and other contaminants. This study evaluated a chitosan bead as an adsorbent in adsorption process for natural rubber wastewater treatment. The effects of adsorbent dosage, pH, shaking speed and contact time and adsorption isotherm on colour adsorption onto chitosan beads were evaluated using batch experiments. Meanwhile, Langmuir and Freundlich isotherm models were used to validate the experimental data. Maximum removal of 71.5%, for colour was observed for an adsorbent dosage 4.5 g, pH 7, and shaking speed 150 rpm. Equilibrium was achieved in 120 min. The equilibrium data were fitted to Langmuir isotherm model when compared with Freundlich isotherm models
Application of Response Surface Methodology (RSM) to optimize COD and Ammoniacal Nitrogen removal from Leachate using Moringa and Zeolite mixtures
No full textThis paper reported the optimization of COD and NH3-N reduction from a stabilised leachate by zeolite (ZE) and moringa oleifera leaf powder (MP) mixture using response surface methodology (RSM) and central composite design (CCD). Quadratic polynomial equations were obtained for the removal process. An initial experiment was conducted to establish the optimum mixed ratio between ZE:MP and resulted in a ratio of 24:16. Independent variables investigated in the subsequent optimization experiments include pH ,dosage and contact time. The results revealed that the optimal reduction of COD and NH3-N from landfill leachate was considerable at pH 5.9 , optimal time of 113 minutes and 100gL-1 of adsorbent dosage with desirability value of 0.917. The upper limits for the actual versus predicted reduction were 70.14 against 69.13% and 86.94 against 86.55 % respectively for COD and NH3-N which defined that the experimental values were relatively close to the predicted values. The study also revealed that ZE:MP mixture has a very high potential for the remediation of COD and NH3-N from a stabilized leachate
Utilization of waste paper sludge as an alternative adsorbent for the adsorption of Ammonia Nitrogen and COD in stabilized landfill leachate
No full textRenewable 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. Keywords: Renewable fuel, ethanol, numerical simulation, auto ignition, single-step mechanism Waste paper sludge (WPS) is produced by the paper industry during the wastewater treatment process of paper production. The disposal techniques of WPS pose a great concern for the environment. This study focuses on the evaluation of WPS as an alternative absorbent material to activated carbon (AC) for the removal of contaminants from stabilized landfill leachate. Ammonia (NH3-N) and chemical oxygen demand (COD) were identified as the two major contaminants in landfill leachate. Both AC and WPS were mixed together in different ratios. The optimum replacement for the absorbent was determined using the batch technique. The adsorption batch study was carried out under the optimum pH of 7, with a shaking speed of 200 rpm and a contact time of 120 minutes. The adsorption isotherms indicated that the Langmuir model was better fitted to the experimental data as it was found to have the highest regression values. The Langmuir adsorption capacities for COD and NH3-N were 32.26 mg/g and 21.60 mg/g, respectively. The optimum replacements were initially at two different ratios of 2:2 and 3:1 based on the optimum removal of COD and NH3-N, respectively. However, the final optimum replacement for the absorbents (AC: WPS) in this study was the ratio of 2:2 due to the higher removal of COD (85.9%) and NH3-N (49.3%)
Chitosan ultilization in biocomposite adsorbent in Iron (Fe) removal from landfill leachate
No full textLeachate are very high strength wastewaters that contain a variety of pollutants that pose a serious threat to the environment if appropriate control measure is ignored. Composite adsorbent is an emerging, interesting and attractive alternative to conventional adsorbents and having the ability to act as catalysts due to their high reactivity and excellent selectivity towards specific pollutant compounds. This study investigated the potential of biocomposite adsorbent made from a combination of chitosan, feldspar and zeolite (CFZ) for the treatment of Iron (Fe) from leachate wastewater. Leachate characterization and batch adsorption experiments was conducted to determine the optimum conditions for pH, dosage and contact time parameter in the removal of Fe. The result shows that the concentration of Fe was 15.82 which exceeded the recommended limit. The optimum conditions also occurred at pH 5 with 6 gram of biocomposite dosage and at 180 minutes contact time. The corresponding removal efficiency for Fe is 90% with 0.0127 mg/g uptake capacity
Treatment of biodiesel wastewater using Ferric Chloride and Ferric Sulfate
No full textThe production of biodiesel through the transesterification method produces a large amount of wastewater that contains high level of chemical oxygen demand (COD) and oil and grease. In this study, coagulation was adopted to treat the biodiesel wastewater. Two types of coagulants were examined using standard jar test apparatus, i.e. ferric chloride and ferric sulfate. The effects of pH and coagulant dosage were examined at 150 rpm of rapid mixing and 20 rpm slow mixing and 30 min settling time, higher removal of SS (over 80%), colour (over 80%), COD (over 50%) and Oil and Grease (over 90%) were achieved at pH 6. Ferric Chloride was found to be superior was observed at reasonable lower amount of coagulant i.e. 300 mg/L. The result indicated that coagulation and flocculation process had contributed bigger roles in integrated treatment system
Optimization of batch conditions for COD and Ammonia Nitrogen removal using cockle shells through response surface methodology
No full textThe optimal conditions for the reduction of COD and NH3-N using cockle shells (CS) from a stabilised landfill effluent were analyzed. The influence of two variables (adsorbent dosage and pH) were analysed through the application of response surface methodology (RSM) and central composite design (CCD). Quadratic models were developed for the removals of COD and NH3-N parameters. The optimum conditions for removal of 65.6% and 53.6% for COD and NH3-N respectively was achieved at pH 6.34, adsorbent dosage of 20.21 g having 0.888 desirability value. The model F-value obtained for NH3-N removal Prob. > F value of 0.0001 with F-value of 104.21 was obtained. Similarly the Prob. > F value of < 0.0001 for COD with F-value of 82.74 was obtained, these P-values confirmed the significance of the model. The predicted response versus the experimental response depicted that the experimental data were relatively close to the predicted data. Thus, the generated models significantly enclosed the correlation between the process variables and the response
COD and ammonia removal from landfill leachate using mixed granular adsorbent media
No full textLandfills 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
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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