Effect of Microbes and Vermicompost applied with different phosphorus levels on yield and phosphorus uptake of wheat and maize

Abstract

Two easily available, ecofriendly and abundantly found agro-wastes peels of Trapa natans (TN-Ps) and Citrullus lanatus (CL-Ps) were locally taken form Lahore and nearby areas, of Punjab, Pakistan. The peels were dried, grinded to 80 mesh size, for chemical modification with different chemical modifying agents to alter their surface morphology by providing numerous active adsorption sites for efficient rate of adsorption of dyes from aqueous media. The optimized and good adsorption results were obtained by chemically treatment with easily available tricarboxylic organic acid (C6H8O7) commonly known as citric acid. FT-IR and SEM characterizations were evidenced for the additional active adsorption sites on the chemically modified peels of Trapa natans (CTNP) and Citrullus lanatus (CCLP) than their native forms Native forms (NTNP) and (NCLP) respectively. It was investigated that acid processed biomass of agro-wastes had given good, quicker and promising results for the adsorptive removal of three toxic, carcinogenic, hazardous model dyes, Brilliant green dyes (BLG), Rhodamine B (RBD) and Congo red dyes (CRD), from aqueous environment in batch mode study. The optimum conditions and operational parameters were determined to apply isothermal models, kinetics equilibrium and thermodynamic studies during experimental work. It was investigated after the interpretation of adsorption experimental data that Langmuir and Temkin isotherms were followed in better way for adsorptive removal of (BLG) and (CRD), than Freundlich equilibrium models while eradication of (RBD) from aqueous solution followed Langmuir isotherm in better way than Freundlich isotherms. Initial pH had major function during adsorption studies. Optimized (pH=5), was suitable for the adsorptive eradication of basic dyes like (BLG) and (RBD) while low (pH= 4) was effective for the protonation of adsorbents, resulting chelation between amino groups of (CRD) and COOH groups on the surface of adsorbents. Correlation coefficients (R2) for removal of (BLG), for Langmuir isotherm were 0.985, 0.986, 0.985 and 0.998 while qmax values were 108.7, 128, 145 and 189 mg/g on NTNP, CTNP, NCLP and CCLP respectively while (BLG) Correlation coefficients for Temkin isotherm were 0.98, 0.99, 0.97 and 0.99 on NTNP, CTNP, NCLP and CCLP respectively. Similarly, Correlation coefficients (R2) for adsorptive removal of (RBD) for Langmuir model was 0.97 for NTNP and 0.99 for each CTNP, NCLP and CCLP, while qmax values were 4.88, 15.63, 8.54 and 26.20 mg/g on NTNP, CTNP, NCLP and CCLP respectively. R2, values for (CRD) eradication of Langmuir isotherm were 0.97, 0.98, 0.99 and 0.99 while qmax values were xvii 3.14,13.8 and2.91 and 19.7mg.g-1 on NTNP, CTNP, NCLP and CCLP respectively, while, ‘R2’ for Temkin isotherm were 0.92, 0.99, 0.88 and 0.97 on NTNP, CTNP, NCLP and CCLP respectively. It was observed that Temkin isotherm was fit in better way for adsorptive elimination of acidic dye (CRD) on (CTNP and CCLP) as compre raw forms adsorbents (NTNP and NCLP). Thus the adsorption mechanism was monolayer, homogeneously and chemisorption on adsorption active sites equally scattered and dispersed on the surfaces of (NTNP, NCLP, CTNP and CCLP). The adsorption active binding sites were more in citric acid treated adsorbents (CTNP, CCLP) than their unmodified forms (NTNP, NCLP). Citric acid treated adsorbents (CTNP, CCLP) performed good adsorption of dyestuffs due to more available adsorption active binding sites than unmodified adsorbents (NTNP and NCLP). Kinetic studies revealed that adsorption mechanism has followed Pseudo 2nd order. Thermal behavior of adsorption mechanism like (ΔG0), Enthalpy change (ΔH0), Entropy change (ΔS0) and Energy of activation (Ea) for all cases had shown, good and efficient physicochemical phenomenon for adsorbate and adsorbent associations. Therefore, (CTNP and CCLP) had given good, efficient and quicker adsorptive removal of (BLG), (RBD) and (CRD) than (NTNP and NCLP) as well as from previous reported data. This investigation strongly support that both novel citric acid treated adsorbents (CTNP and CCLP) are appropriate and fit for bulk scale removal of toxic, carcinogenic and hazardous Brilliant green dyes, Rhodamine B and Congo red dyes from wastewater.