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The objective of the present study is to investigate the status of pollution load in River Yamuna, Delhi.The 13 sites for sampling, spread through the Delhi stretch of Yamuna, starting from the Wazirabad barrage till the Okhla barrage has been selected. Physicochemical parameters such as pH, temperature, DO (Dissolved oxygen), TDS (Total dissolved solids), salinity and conductivity were determined. The concentration of heavy metals (Cd, Ni, Zn, Fe, Cu, Pb, and Cr,) were assessed and found to be (0.03, 0.025, 1.365, 6.175, 0.08, 0.02, and 0.03) respectively. Varying concentration of heavy metals was found due to the widespread discharge of industrial effluents into the river. The overall mean concentration of heavy metals was observed in the following order Fe > Zn > Cu > Ni > Cr > Pb > Cd. It can be concluded that our study area as a whole is critically polluted in terms of mean Fe concentration (6.175 mg/L) due to pollutant load from various anthropogenic activities and need treatment before further use. This dataset is beneficial for policymakers, and researchers in the field of River Yamuna water quality management.

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Reactive chromatography is beneficial for a reaction where reaction equilibrium limits productivity, the product forms azeotropes with the reactants, and product separation is difficult due to nonideality in the phase equilibrium. 2,2 Di-methoxy propane (DMP) production from methanol and acetone is one such example where DMP equilibrium conversion is less than 15% at 15 °C reaction temperature in a conventional batch process. Furthermore, DMP forms azeotropes with acetone and methanol, and product separation is difficult due to nonideality in the phase equilibrium. In this work, synthesis of DMP from methanol and acetone using an acidic resin (Amberlyst-15) as an adsorbent/catalyst is investigated in a fixed-bed chromatographic reactor (FBCR). Addition of solvents such as hexane or cyclohexane into the reaction system in the FBCR favorably influences the affinity of acetone and DMP to the catalyst bed. The addition of equal molar amounts of hexane and acetone results in an increase in the affinity of acetone toward the resin and a decrease in the affinity of DMP toward the resin. Thus, with the aid of solvents, one can completely exhaust the acetone in the reaction regime and thus decrease the downstream processing cost drastically. Moreover, DMP yield increases threefold compared to the case when a solvent is not used. The parameters in the reaction kinetics, dispersion coefficient, and adsorption parameter were estimated by conducting independent experiments in the FBCR. The reaction kinetics and adsorption isotherm results are obtained from the FBCR implemented in the model, which predicts the results that are in good agreement with the experimental data.

In the present study, sewage sludge (SS) was used to synthesize activated carbon (AC) which was further utilized as adsorbent for the removal of ciprofloxacin (CPX) from synthetic wastewater. The adsorbent was prepared by chemical activation method using ZnCl 2 as activating agent. Design of experiments (DOE) approach was explored to determine the optimum operating conditions for the synthesis of AC and CPX removal from the wastewater. The optimum conditions for AC synthesis (i.e., carbonization temperature = $500 C, activation time = 30 min, and impregnation ratio = 2.26) were decided based on results for three response parameters, that is, adsorbent yield, methylene blue removal, and iodine number. The synthesized adsorbent showed $93% CPX removal (initial CPX concentration = 100 mg/L) at the following optimum conditions: adsorbent dose = 1.31 g/L, pH = 7 and reaction time = 12 h. Langmuir isotherm model was best fit to the equilibrium adsorption data (maximum adsorption capacity of SS derived AC = 102 mg/g) whereas pseudo-second order model showed the best fit to adsorption kinetic data (adsorption capacity = 77.5 mg/g). An effort was also made to reduce fresh water requirement for adsorbent synthesis by recycling the wastewater produced during chemical activation of SS. Practitioner points• Experiment design approach was used for optimization of adsorbent preparation conditions and CPX removal conditions by waste derived adsorbent.• Sewage sludge derived adsorbent had BET surface area of 564 m 2 /g which is comparable to commercial activated carbon.• 93% CPX adsorption with the sewage sludge derived adsorbent at optimum conditions.• Langmuir model better suited the CPX adsorption data.• Wastewater recycling and ZnO recovery from wastewater produced during adsorbent synthesis were performed.