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Natural material, agricultural waste, and industrial waste are locally accessible resources that are utilized as environment-friendly and inexpensive sorbent. The natural abundance source like green waste mussel shell (GWMS) adsorbent makes them an advantageous basic sorbent material to produce inexpensive water treatment adsorbent. This study addresses the evaluation of GWMS as an efficient sorbent material to minimize the utilization of traditional adsorbents namely activated carbon (AC) and zeolite (ZEO) for removing pollutants from leachate. COD and ammoniacal nitrogen (NH3–N) were identified as the two problematic parameters in landfill leachate. Batch adsorption experiments were performed with 100 mL of prepared leachate solution in 2.5 g, 7.5 g, and 12.5 g dosages. The leachate solution was shaken in an incubator for 2 h at 200 rpm shaking speed and pH 7. The GWMS dosage at 7.5 g illustrated that the removal percentage of COD is 71% and that of NH3–N is 47%. The adsorption capacity related to the complete monolayer coverage of saturated molecules shows that the maximum adsorption capacity of COD is 47.39 mg g−1 and that of NH3–N is 26.18 mg g−1. Langmuir and Freundlich values are better described by Langmuir than Freundlich based on R2 values for COD > NH3–N where 0.9941 > 0.9891. The R2 values for COD > NH3–N for the linear plot of the pseudo-second-order were 0.9997 > 0.9763, respectively. [ABSTRACT FROM AUTHOR]

The physical appearance of leachate when it emerges from a typical landfill site is a strongly odoured black, yellow or orange colored cloudy liquid which contains organic and inorganic pollutants which makes it unsatisfactory to be released in water bodies without any prior treatment. The goal of current study was to examine the effectiveness of waste green mussel shell (WGMS) for the removal of pollutants from stabilized leachate. Chemical oxygen demand (COD) and ammonium nitrogen (NH3-N) was investigated as the two major contaminants in leachate. In this study, adsorption method employed for the treatment of landfill leachate. Static batch experiment was carried out with 100 mL leachate sample with pH 7, contact time 120 min, dosage 4.0 g with 200 rpm shaking speed. The best removal was achieved at 2.0 g with the removal percentage of COD and N-NH3 were 58% and 48%, respectively. Langmuir isotherm adsorption model showed best fitted with coefficient of determination for COD with the value of R² = 0.9944 and NH3-N with the value of R² = 0.9918 respectively as compared to Freundlich model shows the value for COD with the value of R² = 0.9825 and NH3-N with the value of R² = 0.9508. Thus, it indicates adsorbent adsorption occurs monolayer adsorption on homogeneous surface. The WGMS provides a significantly lower cost medium for reduction of COD and NH3-N. [ABSTRACT FROM AUTHOR]

The suitability of micro peat (MP) and activated carbon (AC) mixed media as a composite adsorbent for the landfill leachate treatment in terms of COD reduction and color removal was investigated in this study. All the adsorption media was pulverized and sieved to a particle size of 150 µm. The MP-AC composite media efficiently removed 87% COD at optimal ratio 1.5:2.5 and 74% color at optimal ratio 2.0:2.0, within 120 min of contact time, 200 rpm of shaking speed at pH 7. The findings revealed that Langmuir isotherm best described the uptake of COD and color which implies that the adsorption of leachate in this study onto MP-AC composite media was homogeneous on a mono layer surface. The kinetic data and the factor controlling adsorption process fitted better to the pseudo-second- order model. Energy of adsorption (E) were observed as 267.26 kJ mol-1 and 79.06 kJ mol-1 for COD and color respectively indicating chemisorption as the limiting controlling step for the reduction of COD and color onto MP-AC composite media. The overall rate of the COD and color adsorption processes onto MP-AC composite media appears to be dominated by chemisorption. The pattern of adsorption showed that micro peat offers a cost effective alternative and can be utilized as partial replacement of conventional media (AC) for the removal of organic matters from landfill leachate. [ABSTRACT FROM AUTHOR]

The reduction of chemical oxygen demand (COD) from palm oil mill effluent (POME) is very significant to ensure aquatic protection and the environment. Continuous adsorption of COD in a fixed bed column can be an effective treatment process for its reduction prior to discharge. Adsorption capacity of bone derived biocomposite synthesized from fresh cow bones, zeolite, and coconut shells for the reduction in the organic pollutant parameter was investigated in this study in a fixed bed column. The effect of influent flow rate (1.4, 2.0, and 2.6 mL/min) was determined at an influent pH 7. The optimum bed capacity on the fabricated composite of surface area of 251.9669 m2/g was obtained at 1.4 mL/min at breakthrough time of 5.15 h influent POME concentration. The experimental data were fitted to Thomas, Adams–Bohart, and Yoon–Nelson models fixed bed adsorption models. It was revealed that the results fitted well to the Adams Bohart model with a correlation coefficient of R2 > 0.96 at different influent concentration. Adsorption rate constant was observed to increase at lower flow rate influent concentration, resulting in longer empty bed contact time (EBCT) for the mass transfer zone of the column to reach the outlet of the effluent concentration. In general, the overall kinetics of adsorption indicated that the reduction in COD from POME using a bone-biocomposite was effective at the initial stage of adsorption. The pore diffusion model better described the breakthrough characteristics for COD reduction with high correlation coefficient. Shorter breakthrough time compared to EBCT before regeneration indicated that the bone composite was suitable and effective for the reduction in COD from POME using fixed bed column adsorption. [ABSTRACT FROM AUTHOR]