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In this study, biochar was prepared from Sidr plant leaves and used for the treatment of ciprofloxacin (CIP)-contaminated water. CIP is important class of emerging water pollutants from pharmaceutical industries. The biochar showed 65% adsorption efficiency and 43.48 mg/g adsorption capacity of CIP. Adsorption efficiency as well as adsorption capacity were improved to 91% and 62.50 mg/g, respectively, by phosphoric acid (H 3 PO 4 ) modified biochar. Removal of CIP by the prepared biochar was due to different surface functional groups of CIP and biochar as revealed from the study of different characterization analyses. The presence of PO 4 group in modified biochar led to maximum binding of CIP. Also, the modified biochar showed higher reusability potential and less leaching of ions when compared to the raw biochar. Removal of CIP was affected by concentrations of CIP, the amount of biochar and different pH's; the maximum removal of CIP was achieved at pH 4. The Freundlich and 3- group in modified biochar led to maximum binding of CIP. Also, the modified biochar showed higher reusability potential and less leaching of ions when compared to the raw biochar. Removal of CIP was affected by concentrations of CIP, the amount of biochar and different pH's; the maximum removal of CIP was achieved at pH 4. The Freundlich and pseudo-first-order models best fitted the removal of CIP by modified biochar. Advanced characterization techniques were applied to investigate surface and physiological characteristics of the biochar and modified biochar. The modification showed high impact on the performance and stability of biochar. The study showed significant impacts of modification on the potential of the biochar for treatment of CIP-contaminated water.

In this study, biochar was prepared from Sidr plant leaves and used for the treatment of ciprofloxacin (CIP)-contaminated water. CIP is important class of emerging water pollutants from pharmaceutical industries. The biochar showed 65% adsorption efficiency and 43.48 mg/g adsorption capacity of CIP. Adsorption efficiency as well as adsorption capacity were improved to 91% and 62.50 mg/g, respectively, by phosphoric acid (H3PO4) modified biochar. Removal of CIP by the prepared biochar was due to different surface functional groups of CIP and biochar as revealed from the study of different characterization analyses. The presence of PO43– group in modified biochar led to maximum binding of CIP. Also, the modified biochar showed higher reusability potential and less leaching of ions when compared to the raw biochar. Removal of CIP was affected by concentrations of CIP, the amount of biochar and different pH's; the maximum removal of CIP was achieved at pH 4. The Freundlich and pseudo-first-order models best fitted the removal of CIP by modified biochar. Advanced characterization techniques were applied to investigate surface and physiological characteristics of the biochar and modified biochar. The modification showed high impact on the performance and stability of biochar. The study showed significant impacts of modification on the potential of the biochar for treatment of CIP-contaminated water. [ABSTRACT FROM AUTHOR]

[Display omitted] • Treatment of CIP was compared by different activated PMS-based process. • The UV-C/Fe2+/PMS-based process gave better performance in the removal of CIP. • The activated PMS yielded ●OH and SO 4 ●− which showed high reactivity with CIP. • The Cu2+ improve production rate of ●OH and SO 4 ●− and facilitated removal of CIP. • Degradation products and ecotoxicities of CIP and its DPS were analyzed. Ciprofloxacin (CIP) is a valuable antibiotic and discharged in huge quantities in aquatic environment. Different •OH and SO 4 •−-based advanced oxidation technologies (AOTs), e.g., Fe2+/PMS, UV-C/PMS, and UV-C/Fe2+/PMS are developed for treatment of CIP. The removal of CIP by Fe2+/PMS, UV-C/PMS and UV-C/Fe2+/PMS was 63, 77, and 87 %, respectively, under identical conditions which showed better performance of UV-C/Fe2+/PMS. The UV-C/Fe2+/PMS also caused high removal of total organic carbon of CIP. This high performance of UV-C/Fe2+/PMS-based AOTs possibly looked due to dual activation of PMS by UV-C and Fe2+. The removal of CIP by the three AOTs was found due to •OH and SO 4 •− and the later showed high reactivities with CIP, i.e., 2.45 × 109 and 2.35 × 109 M−1 s−1, respectively. The study of factors affecting the reactivities and/or yield of •OH and SO 4 •− diminished CIP degradation efficiency. The change in pH of solution and temperature and doses of Fe2+, PMS, and CIP exhibited significant impacts on the removal of CIP. The addition of inorganic ions showed strong inhibiting effects of NO 2 –, CO 3 2–, and HCO 3 – while Cu2+ showed facilitating role. Analysis of degradation of CIP by GC–MS was used to develop proposed pathways. Acute and chronic toxicities of CIP and its products were measured by ECOSAR program and showed the resulting products to be non-toxic. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Highly stable nZVMn was synthesized by chemical reduction method. • Addition of S 2 O 8 2− promoted the performance of nZVMn. • Second-order rate constants of CIP with OH and SO4 − were calculated. • Proposed pathways for conversion of CIP into TPs were developed. • Acute and chronic toxicities of CIP and its TPs were evaluated. Abstract Nano zerovalent manganese (nZVMn, Mn0) materials have been synthesized in this study and used for degradation of ciprofloxacin (CIP), an emerging water pollutant. The investigation of physiological characteristics of Mn0 by different characterization techniques proved successful formation of Mn0 by the chemical reduction method and found it to be highly crystalline. The Mn0 was highly efficient and resulted in 63% degradation of CIP using [CIP] 0 = 10 mg/L and [Mn0] 0 = 1.0 g/L at a reaction time of 80 min. Addition of S 2 O 8 2− to Mn0 promoted removal efficiency of CIP from 63 to 95% at a reaction time of 80 min using the conditions of [CIP] 0 = 10 mg/L, [Mn0] 0 = 1.0 g/L, and [S 2 O 8 2−] 0 = 50 mg/L. The presence of OH and SO 4 − scavengers inhibited the degradation of CIP by Mn0/S 2 O 8 2−. The comparable second-order rate constants of CIP with OH and SO 4 − were calculated to be 2.35 × 109 and 2.10 × 109 M−1 s−1, respectively. High S 2 O 8 2− and Mn0 concentrations and low pH accelerated the degradation of CIP. However, removal efficiency of CIP by Mn0 with the added S 2 O 8 2− was inhibited using high CIP concentration, high pH, inorganic anions, and NOM. Degradation pathways from OH and SO 4 − based degradation of CIP were developed. Acute and chronic toxicities of CIP and its products were estimated, showing the final product to be non-toxic. The as-synthesized Mn0 was found to be stable as well as environmentally friendly for treating CIP. This study suggests that Mn0 with the added S 2 O 8 2− is a promising alternative for potential remediation and detoxification of CIP and other emerging water pollutants. [ABSTRACT FROM AUTHOR]

Ciprofloxacin (CIP) is a widespread emerging water pollutant and thus its removal from aquatic environment is vital. The use of Fe3+/H2O2 and Fe2+/H2O2 resulted in 38 and 64% removal of CIP (8.0 ppm), respectively, within 80 min reaction time (pH 5.8, [H2O2]0 = 80 ppm, and [iron]0 = 20 ppm). Low pH, high temperature, high dose of H2O2 and Fe2+, and low CIP concentration facilitated removal of CIP. The radical scavenger studies proved in situ generated OH to be involved primarily in the removal of CIP. The effect of temperature was used to estimate enthalpy and activation energies of the removal of CIP. At 800 min reaction time, the Fe2+/H2O2 resulted in 54% mineralization of CIP using 16.0 ppm [CIP]0, 320.0 ppm [H2O2]0, and 40.0 ppm [Fe2+]0. The potential degradation pathways of CIP established from the degradation of CIP by OH and products evolved was found to be initiated at C6 through the loss of fluoride ion. The acute and chronic toxicities of CIP and its degradation products were estimated with the final product found to be non-toxic. The results suggest that Fe2+/H2O2-mediated AOPs have high potential for degradation as well as toxicity elimination of CIP and its degradation products. [ABSTRACT FROM AUTHOR]

• The presence of H 2 O 2 with iron promoted the removal of CIP. • The presence of OH scavengers inhibited removal of CIP by Fe2+/H 2 O 2. • Mineralization of CIP by Fe2+/H 2 O 2 -mediated AOPs was explored. • Potential pathways for conversion of CIP into degradation products were developed. • Acute and chronic toxicities of CIP and its degradation products were estimated. Ciprofloxacin (CIP) is a widespread emerging water pollutant and thus its removal from aquatic environment is vital. The use of Fe3+/H 2 O 2 and Fe2+/H 2 O 2 resulted in 38 and 64% removal of CIP (8.0 ppm), respectively, within 80 min reaction time (pH 5.8, [H 2 O 2 ] 0 = 80 ppm, and [iron] 0 = 20 ppm). Low pH, high temperature, high dose of H 2 O 2 and Fe2+, and low CIP concentration facilitated removal of CIP. The radical scavenger studies proved in situ generated OH to be involved primarily in the removal of CIP. The effect of temperature was used to estimate enthalpy and activation energies of the removal of CIP. At 800 min reaction time, the Fe2+/H 2 O 2 resulted in 54% mineralization of CIP using 16.0 ppm [CIP] 0 , 320.0 ppm [H 2 O 2 ] 0 , and 40.0 ppm [Fe2+] 0. The potential degradation pathways of CIP established from the degradation of CIP by OH and products evolved was found to be initiated at C 6 through the loss of fluoride ion. The acute and chronic toxicities of CIP and its degradation products were estimated with the final product found to be non-toxic. The results suggest that Fe2+/H 2 O 2 -mediated AOPs have high potential for degradation as well as toxicity elimination of CIP and its degradation products. [ABSTRACT FROM AUTHOR]