Facile synthesis and implications of novel hydrophobic materials: Newer insights of pharmaceuticals removal

520-531The residual escape of pharmaceuticals from wastewater treatment plants (WWTP) is a serious environmental concern due to the adverse effects towards living organisms. Therefore, it is important to devise the newer technologies for safe and efficient elimination of emerging micro-pollutants from effluents of existing water treatment plants. Bentonite is grafted with 3-mercaptopropyletrimethoxy silane by facile one-pot method to obtain dense composite material (MPTS/BENT).The materials are characterized by the FT-IR, XRD, BET and SEM/EDX analytical tools. Various parametric experiments conducted for the removal of tetracycline hydrochloride (TCH) and triclosan (TCS) using MPTS/BENT under batch experimentations. Further, column adsorption experiments have been performed.The incorporation of organosilane with bentonite is confirmed by FT-IR and EDX analyses. BET surface area analysis showed that the surface area of MPTS/BENT is significantly small compared with pristine clay. pH dependent sorption of TCH and TCS is almost unaffected within the pH 3.0 to 7.0. Rapid uptake of TCH and TCS by MPTS/BENT followed PSO kinetics. High percentage removal was achieved at wide concentration range of pollutants. The uptake of TCH and TCS is unaffected on increasing the background electrolyte concentrations for 1000 times. Column experiment confirmed the high efficiency of MPTS/BENT towards these pollutants. Moreover, the removal of TCH/or TCS from real water sample at varied pH values showed that the synthesized composite is selective and efficient towards these micro-pollutants. This study showed that the synthesized material, i.e., MPTS/BENT could be efficiently employed for the additional purification of WWTP effluents

Facile synthesis and implications of novel hydrophobic materials: Newer insights of pharmaceuticals removal

The residual escape of pharmaceuticals from wastewater treatment plants (WWTP) is a serious environmental concern due to the adverse effects towards living organisms. Therefore, it is important to devise the newer technologies for safe and efficient elimination of emerging micro-pollutants from effluents of existing water treatment plants. Bentonite is grafted with 3-mercaptopropyletrimethoxy silane by facile one-pot method to obtain dense composite material (MPTS/BENT).The materials are characterized by the FT-IR, XRD, BET and SEM/EDX analytical tools. Various parametric experiments conducted for the removal of tetracycline hydrochloride (TCH) and triclosan (TCS) using MPTS/BENT under batch experimentations. Further, column adsorption experiments have been performed.The incorporation of organosilane with bentonite is confirmed by FT-IR and EDX analyses. BET surface area analysis showed that the surface area of MPTS/BENT is significantly small compared with pristine clay. pH dependent sorption of TCH and TCS is almost unaffected within the pH 3.0 to 7.0. Rapid uptake of TCH and TCS by MPTS/BENT followed PSO kinetics. High percentage removal was achieved at wide concentration range of pollutants. The uptake of TCH and TCS is unaffected increasing the background electrolyte concentrations for 1000 times. Column experiment confirmed the high efficiency of MPTS/BENT towards these pollutants. Moreover, the removal of TCH/or TCS from real water sample at varied pH values showed that the synthesized composite is selective and efficient towards these micro-pollutants. This study showed that the synthesize material, i.e., MPTS/BENT could be efficiently employed for the additional purification of WWTP effluents

Efficient use of Ferrate(VI) in the remediation of aqueous solutions contaminated with potential micropollutants: Simultaneous removal of triclosan and amoxicillin

532-542Ferrate(VI) is a safer oxidant compared to the often used oxidant in various wastewater treatment plants since the ferrate(VI) is devoid with the generation of harmful by-products. Hence, the present study is aimed to obtain laboratory experimental data for the treatment of water adulterated with emerging micro-pollutant (triclosan and amoxicillin) using the ferrate(VI). The parametric studies enabled us to deduce the kinetics of ferrate(VI) removal. The molar stoichiometry of ferrate(VI) and micro-pollutant was obtained as 2:1. Further, the mineralization of triclosan and amoxicillin is obtained which further enhances the applicability of ferrate(VI) in the waste water treatment. The simultaneous removal of these two pollutants (triclosan and amoxicillin) are extensively studied using the ferrate(VI). Moreover, the pH dependent degradation using ferrate(VI) is enabled to deduce the mechanism of removal. Additionally, the real matrix samples using the natural spring water (Tuikhur water) spiked with these micro-pollutants showed that the ferrate(VI) efficiency is almost unaffected at least in the removal of these two micro-pollutants. This showed the selectivity of the ferrate(VI) in the treatment process

Removal of emerging micropollutants from water using hybrid material precursor to natural sericite clay

602-610The occurrence of a wide range of micropollutants in natural aquatic environment has been reported in different parts of the world. These compounds are harmful for the aquatic life and human beings. Diclofenac and clofibric acid are the two common toxic micropollutants due to very large production and high consumption by humans. The present communication addresses the removal of diclofenac and clofibric acid from aqueous solutions using the hybrid material obtained by incorporating 3-aminopropyltriethoxysilane (APTES) onto the activated sericite clay. Initially, sericte clay was treated for activation and further modified with organosilane to obtain hybrid material. The materials were characterized using SEM, BET surface area, XRD, and FT-IR analyses. SEM and BET surface area analyses showed that the textural property of sericite clay was greatly changed after activation and the surface area was immensely increased from 3.65 to 62.92 m2/g. The organosilane was anchored on the activated clay and confirmed with FTIR analysis. Batch adsorption experiments showed that the diclofenac and clofibric acid removal is maximum at pH 6.0 to 7.0 and the adsorption of these two micropollutants were observed to be very fast and the time dependent adsorption data were best fitted to pseudo-second order kinetic model. The maximum adsorption capacity of diclofenac and clofibric acid using APTES-sericite hybrid material was found to be 1.868 and 1.749 mg/g, respectively. Furthermore, the loading capacities of the column packed with APTES-sericite hybrid material were found to be 0.789 and 1.095 mg/g. Therefore, this study indicated that the APTES-sericite hybrid material must be an useful material for the effective removal of diclofenac and clofibric acid from aqueous waste

Simultaneous removal of PAHs and metal contaminants from water using magnetic nanoparticle adsorbents

Many industrial wastewaters are contaminated with both heavy metal ions and organic compounds, posing a major threat to public health and the environment. In this study, magnetic nanoparticle adsorbents, namely Mag-PCMA-T, which contain a maghemite core and a silica mesoporous layer that permanently confines surfactant micelles within the mesopores, were synthesized to achieve simultaneous removal of polycyclic aromatic hydrocarbons (PAHs) (1mg/L) and metal contaminants (1mg/L). The individual removal efficiency of Cd(2+) and acenaphthene using Mag-PCMA-T was evaluated under a range of initial ion concentrations and adsorbent dosages, as well as the competitive adsorption with Cd(2+) and acenaphthene simultaneously present. The isotherms and kinetics of Cd(2+) and acenaphthene sorption onto Mag-PCMA-T were determined. Mag-PCMA-T removed >85% of the acenaphthene in <30min, with relatively high sorption capacity (up to 1060mg/kg). Mag-PCMA-T also exhibited high sorption capacity for Cd(2+) (up to 2250mg/kg). The simultaneous sorption performance was stable across a wide pH range (4-9) as well as in the presence of competitive metal ions (Ca(2+) and Mg(2+)) or natural organic matters. The Mag-PCMA-T can be regenerated and reused, providing a sustainable, fast, convenient, and efficient approach for water treatment

Simultaneous Removal of Hg(II) and Phenol Using Functionalized Activated Carbon Derived from Areca Nut Waste

Areca nut waste was utilized to obtain high surface area activated carbon (AC), and it was further functionalized with succinic anhydride under microwave irradiation. The surface morphology and surface functional groups of the materials were discussed with the help of scanning electron microscope(SEM) images and fourier transform infra-red (FT-IR) analysis. The specific surface area of the AC and functionalized-AC was obtained by the Brunauer-Emmett-Teller (BET) method, and found to be 367.303 and 308.032 m2/g, respectively. Batch experiments showed that higher pH favoured the removal of Hg(II), whereas the phenol removal was slightly affected by the changes in the solution pH. The kinetic data followed pseudo-first order kinetic model, and intra-particle diffusion played a significant role in the removal of both pollutants. The maximum sorption capacity of Hg(II) and phenol were evaluated using Langmuir adsorption isotherms, and found to be 11.23 and 5.37 mg/g, respectively. The removal of Hg(II) was significantly suppressed in the presence of chloride ions due to the formation of a HgCl2 species. The phenol was specifically adsorbed, forming the donor–acceptor complexes or π–π electron interactions at the surface of the solid. Further, a fixed-bed column study was conducted for both Hg(II) and phenol. The loading capacity of the column was estimated using the nonlinear Thomas equation, and found to be 2.49 and 2.70 mg/g, respectively. Therefore, the study showed that functionalized AC obtained from areca nut waste could be employed as a sustainable adsorbent for the simultaneous removal of Hg(II) and phenol from polluted water