Muhammad Saeed | Government College University Faisalabad (original) (raw)

Papers by Muhammad Saeed

Pharmaceutical wastewater is a frequent kind of wastewater with high quantities of organic pollut... more Pharmaceutical wastewater is a frequent kind of wastewater with high quantities of organic pollutants, although little research has been done in the area. Pharmaceutical wastewaters containing antibiotics and high salinity may impair traditional biological treatment, resulting in the propagation of antibiotic resistance genes. The potential for advanced oxidation processes (AOPs) to break down hazardous substances instead of present techniques that essentially transfer contaminants from wastewater to sludge, a membrane filter, or an adsorbent has attracted interest. Among a variety of AOPs, electrochemical systems are a feasible choice for treating pharmaceutical wastewater. Many electrochemical approaches exist now to remediate rivers polluted by refractory organic contaminants, like pharmaceutical micro-pollutants, which have become a severe environmental problem. The first part of this investigation provides the bibliometric analysis of the title search from 1970 to 2021 for keywords such as wastewater and electrochemical. We have provided information on relations between keywords, countries, and journals based on three fields plot, inter-country co-authorship network analysis, and co-occurrence network visualization. The second part introduces electrochemical water treatment approaches customized to these very distinct discarded flows, containing how processes, electrode materials, and operating conditions influence the results (with selective highlighting cathode reduction and anodic oxidation). This section looks at how electrochemistry may be utilized with typical treatment approaches to improve the integrated system's overall efficiency. We discuss how electrochemical cells might be beneficial and what compromises to consider when putting them into practice. We wrap up our analysis with a discussion of known technical obstacles and suggestions for further research.

Very recently the green synthesis routes of nanomaterials have attracted massive attention as it ... more Very recently the green synthesis routes of nanomaterials have attracted massive attention as it overcome the sustainability concerns of conventional synthesis approaches. With this heed, in this novel research work we have synthesized the g-C 3 N 4 nanosheets based nanocomposites by utilizing Eriobotrya japonica as mediator and stabilizer agent. Our designed bio-caped and green g-C 3 N 4 nanosheets based nanocomposites have abundant organic functional groups, activated surface and strong adsorption capability which are very favorable for conversion CO 2 into useful products and bisphenol A degradation. Beneficial to further upgrade the performances of g-C 3 N 4 nanosheets, the resulting pristine g-C 3 N 4 nanosheets are coupled with LaFeO 3 nanosheets via SrO bridge. Based on our experimental results such as TEM, XRD, DRS, TPD, TGA, PL, PEC and FS spectra linked with • OH amount it is confirmed that the biologically mediated green g-C 3 N 4 nanosheets are eco-friendly, highly efficient and stable. Furthermore, the coupling of LaFeO 3 nanosheets enlarged the surface area, enhanced the charge separation, while the insertion of SrO bridge worked as facilitator for electron transportation and photoelectron modulation. In contrast to pristine green g-C 3 N 4 nanosheets (GCN), the activities of final resulting sample 6LFOS-(4SrO)-GCN are improved by 8.0 times for CO 2 conversion (CH 4 = 4.2, CO = 9.2 μmol g − 1 h − 1) and 2.5-fold for bisphenol A degradation (88%) respectively. More specifically, our current research work will open a new gateway to design cost effective, eco-friendly and biological inspired green nanomaterials for CO 2 conversion and organic pollutants degradation which will further support the net zero carbon emission manifesto and the optimization of carbon neutrality level.

Semiconductor based photocatalysis is one of the effective techniques of AOPs for environmental r... more Semiconductor based photocatalysis is one of the effective techniques of AOPs for environmental remediation. In present work, the development of an efficient photocatalyst formed by coupling of p-type Bi 2 O 3 and n-type ZnO is reported. The Bi 2 O 3-ZnO heterostructures with 5, 10 and 15% Bi 2 O 3 were synthesized by co-precipitation method. The prepared heterostructures were characterized by various advanced techniques including XRD, XPS, UV-Visible spectroscopy, FTIR, SEM and surface area measurement. The prepared ZnO and Bi 2 O 3-ZnO heterostructures were tested as photocatalysts for photodegradation of dyes using mixed solution of rhodamine B and reactive yellow dyes. The 5% Bi 2 O 3-ZnO heterostructure was found as most efficient photocatalyst with 93 and 91% photodegradation of rhodamine B and reactive yellow dyes, respectively. It was found that incorporation of 5% Bi 2 O 3 with ZnO enhanced the photocatalytic activity about 15 times towards photodegradation of dyes.

The catalytic wet oxidation is one the methods used for elimination of dyes from aqueous medium i... more The catalytic wet oxidation is one the methods used for elimination of dyes from aqueous medium in which various metal based materials can be used as heterogeneous catalysts. Bimetallic oxides as heterogeneous catalysts have gained much attention as bimetallization improve the catalytic properties of the resulting particles. The biosynthetic green method is the most viable and simple method for synthesis of bimetallic oxides nanoparticles. Here, we report the green synthesis of CoFe 2 O 4 particles using Azadirachata indica leaves extract as reducing and stabilizing agent. The synthesized particles were characterized using X-ray diffraction, thermogravimetric analysis, Fourier-transform infrared spectroscopy and scanning electron microscopy. The synthesized CoFe 2 O 4 particles were tested as a catalyst for mineralization of rhodamine B and methylene blue dyes in the presence of hydrogen peroxide in aqueous media. More than 95% dyes degraded in 120 min. The reaction kinetics was described in terms of Langmuir-Hinshelwood mechanism which suggests that molecules of dye and hydrogen peroxide adsorbed surface of CoFe 2 O 4 and then react together.

We herein report the synthesis of zinc oxide and evaluation of its catalytic performance for degr... more We herein report the synthesis of zinc oxide and evaluation of its catalytic performance for degradation of Rhodamine B dye in aqueous medium. Sodium hydroxide and zinc acetate dihydrate were used as precursor materials for synthesis of zinc oxide catalyst. X-ray difractometry, Fourier transform infer red spectroscopy, scanning electron microscopy, thermogravimetric and surface area analyses were used as characterization techniques. Catalytic performance of prepared zinc oxide was evaluated for degradation of Rhodamine B dye in aqueous medium. Catalytic degradation of dye was taking place according to Eley-Rideal mechanism which states that oxygen adsorbed at the surface of ZnO reacts with dye in fluid phase. During the reaction, reactive radicals are formed as a result of electron-hole pair formation between conduction and valence band of zinc oxide catalyst which degrade the dye into water and carbon dioxide.

Desalination and Water Treatment, 2015

This study is focused on oxidative degradation of Methyl Orange, a common azo dye, catalyzed by n... more This study is focused on oxidative degradation of Methyl Orange, a common azo dye, catalyzed by nickel hydroxide in aqueous solution at 303, 313, 323, and 333 K. Sodium hypochlorite, sodium hydroxide, and nickel sulfate hexahydrate in distilled water were used as starting material for preparation of nickel hydroxide. Pyrex glass batch reactor was used to study the effect of various conditions such as temperature, concentration, agitation, and catalyst dose on catalytic degradation of Methyl Orange in aqueous medium. About 80% Methyl Orange was degraded in 120 min. Experimental data were subjected to kinetic analysis using CurveExpert software. Degradation reaction was taking place according to Langmuir-Hinshelwood mechanism. According to this mechanism, the reactants adsorb at the surface of catalyst in first step followed by reaction between adsorbed reactants in second step. Adsorption of Methyl Orange on surface of catalyst followed Langmuir adsorption isotherm. Apparent activation energy, true activation energy, and heat of adsorption were determined as 13.2, 32.7 and-23.5 kJ mol −1 , respectively.

Biosorbents prepared from the waste of Arachis hypogea (peanut) shells, Ziziphus mauritiana (Indi... more Biosorbents prepared from the waste of Arachis hypogea (peanut) shells, Ziziphus mauritiana (Indian jujube/Ber) sawdust and Cassia fistula (amaltas) leaves were used for the removal of Cr(VI) from aqueous media. The prepared biosorbents were characterized by FT-IR, SEM, surface area and pore size analysis. The effects of various parameters like pH, temperature, contact time, adsorbent dose and concentration of Cr(VI) on the sorption of Cr(VI) were investigated. Kinetic studies were carried out and it was observed that equilibrium was established at 360 minutes for each biosorbent system. The applicability of Freundlich and Langmuir adsorption isotherms was investigated. The maximum adsorption capacity of each of the biosorbents in terms of monolayer coverage (q max) was determined. The q max for the peanut shell (P. Shell), sawdust (S. Dust) and Cassia fistula leaves (C. F. Leaves) biosorbents was 4.32, 3.66 and 4.48 mg g À1 , respectively. The adsorption kinetics data was explained by applying the two kinetic equations i.e. the Lagergren pseudo-first order equation and the pseudo-second order equation. It was found that each system followed the pseudo-second order equation, which confirmed the chemical nature of the biosorption process. Thermodynamics parameters such as DG, DH and DS were calculated for each biosorbent system.

Water pollution by the textile industry is a major issue. Therefore, there is a need for methods ... more Water pollution by the textile industry is a major
issue. Therefore, there is a need for methods to remove
organic dyes from industrial effluents. Various metal oxides
have been used as catalysts for the degradation of dyes.
The catalytic efficiency of metal oxides can be enhanced
by doping metal oxides with metals. Here we report the
synthesis and characterization of nano-sized mixed valence
manganese oxide (MnxOy) and silver-doped mixed valence
manganese oxide (Ag@MnxOy). We study their photocatalytic
efficiency for the photo-degradation of the rhodamine
B dye under light irradiation. MnxOy was prepared
using KMnO4, MnSO4 and NH3, and Ag@MnxOy was
prepared using AgNO3 and Calotropis gigantea plant
extract. The prepared materials were characterized by
X-ray diffractometry, scanning electron microscopy and
Fourier transform infrared spectroscopy. Results show that
doping with Ag enhanced the photo-catalytic performance
of MnxOy from 11 to 28% and 45 to 91% degradation of
rhodamine B dye in 15 and 120 min, respectively. This
enhancement is explained by the fact that Ag
doping prevents the recombination of photoexcited electrons
and positive holes, thus enhancing the photo-catalytic
activity of MnxOy.

Synthesis and characterization of zinc oxide nano particles (ZnO NPs) and investigation of their ... more Synthesis and characterization of zinc oxide nano particles (ZnO NPs) and investigation of their catalytic activity for the degradation of methyl orange in aqueous medium has been reported in this work. ZnO NPs were prepared by reaction of zinc acetate dihydrate and sodium hydroxide in distilled water. The prepared ZnO NPs were characterized by XRD, FTIR, SEM TGA and surface area analysis. ZnO NPs were employed as catalyst for oxidative degradation of methyl orange in aqueous medium. The effects of various parameters like time, temperature, initial concentration of dye and catalyst dose on degradation experiments were investigated. Oxidative degradation reaction followed Eley-Rideal mechanism. According to Eley-Rideal mechanism the gaseous reactant, oxygen adsorbs at the surface of catalyst while methyl orange reacts in fluid phase. Adsorbed oxygen transform to reactive radicals through the formation of electron-hole pair between conduction and valence band of zinc oxide catalyst. These active radicals mineralized the dye into water and carbon dioxide.

Optimum absorbed dose for tuning cotton surface is 30 kGy. Good colour strength is obtained at 70... more Optimum absorbed dose for tuning cotton surface is 30 kGy. Good colour strength is obtained at 70 °C keeping M:L¼1:50. Darker shades are obtained by dyeing for 85 min using dye bath of 5 pH. Optimal pre-mordant is 7% tannic acid (TA) and post-mordant is 5% Cu. At these condition colour characteristics has been enhanced. a b s t r a c t Maintaining colour strength and fastness of the fabrics dyed with natural colourants had been the major constraint of utilizing plant based dyes in modern textile practices. The present study was concerned with the extraction of lutein dye from marigold (Tagetes erecta L.) flowers and role of gamma radiation in improving colour strength and fastness characteristics of the extracted dye. The investigation of dyed fabric in spectraflash showed that gamma ray treatment of 30 kGy was the optimum absorbed dose for surface modification to improve its dye uptake ability. Good colour strength was obtained when irradiated cotton (RC, 30 kGy) was dyed with extract of radiated marigold flower powder (RP) at 70 °C for 85 min, keeping M:L of 1:50 using dye bath of pH 5.0. The results from mordanting experiments revealed that 7% of tannic acid as pre-mordant and 5% of Cu as post-mordant were the best treatments to improve colour strength. It was found that gamma ray induced extraction of lutein from marigold flowers had a potential to be utilized as natural dyes in textile sector to produce yellowish green shades.

This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/copyright

Two types of mixed-valence manganese oxides were synthesised by a mechanochemical process in the ... more Two types of mixed-valence manganese oxides were synthesised by a mechanochemical process in the solid phase by chemical reaction of manganese(II) chloride and potassium permanganate at room temperature. The prepared catalysts were characterised by surface area and pore size, particle size, XRD analyses, SEM analyses and oxygen content measurements. These oxides were used as catalysts for oxidation of benzyl alcohol and cyclohexanol in the presence of solvent and also in solvent-free conditions using molecular oxygen as oxidant. The oxidation reactions were heterogeneous in nature where the catalysts were separated from the reaction mixture by simple filtration. Reaction took place in two steps according to the Langmuir -Hinshelwood mechanism. Benzyl alcohol/cyclohexanol and oxygen adsorb at the surface of the catalyst in the first step followed by reaction between adsorbed benzyl alcohol/cyclohexanol in second step. 69.8 kJ mol -1 and 140.8 kJ mol -1 were calculated as the activation energy for benzyl alcohol and cyclohexanol in n-octane as the solvent respectively, with values of 65.1 and 76 kJ mol -1 for benzyl alcohol and cyclohexanol in solvent-free conditions respectively.

Selective oxidation of benzyl alcohol was carried out using molecular oxygen under mild condition... more Selective oxidation of benzyl alcohol was carried out using molecular oxygen under mild conditions at high turnover frequency [TOF] over palladium supported on zirconia. Zirconia was synthesized by co-precipitation of zirconyl chloride with dilute ammonia solution. Palladium supported zirconia was synthesized by incipient wet impregnation method. The high surface area of zirconia was responsible for the better dispersion of palladium metal over the support which improved the accessibility of the relatively large molecules to the active sites, leading to an improved catalytic performance for alcohol oxidation. The catalyst was characterized by different physical and analytical techniques. The catalyst was found to be active and selective towards the formation of benzaldehyde. The TOF was found to be > 6000/hour, which was amongst the highest reported in literature. Langmuir-Hinshelwood kinetic model was found to be applicable to the solvent free oxidation of benzyl alcohol oxidation.

The oxidation of benzyl alcohol in the liquid phase was studied over manganese oxide catalyst usi... more The oxidation of benzyl alcohol in the liquid phase was studied over manganese oxide catalyst using molecular oxygen as an oxidant. Manganese oxide was prepared by a mechanochemical process in solid state and was characterized by chemical and physical techniques. The catalytic performance of manganese oxide was explored by carrying out the oxidation of benzyl alcohol at 323-373 K temperature and 34-101 kPa partial pressure of oxygen. Benzaldehyde and benzoic acid were identified as the reaction products. Typical batch reactor kinetic data were obtained and fitted to the Langmuir-Hinshelwood, Eley-Rideal, and Marsvan Krevelene models of heterogeneously catalyzed reactions. The Langmuir-Hinshelwood model was found to give a better fit. Adsorption of benzyl alcohol at the surface of the catalyst followed the Langmuir adsorption isotherm. The heat of adsorption for benzyl alcohol was determined as -18.14 kJ mol −1 . The adsorption of oxygen followed the Temkin adsorption isotherm. The maximum heat of adsorption for oxygen was -31.12 kJ mol −1 . The value of activation energy was 71.18 kJ mol −1 , which was apparently free from the influence of the heat of adsorption of both benzyl alcohol and oxygen. C

0.1 % Pd/ZrO 2 was synthesized and characterized by various physicochemical techniques and was su... more 0.1 % Pd/ZrO 2 was synthesized and characterized by various physicochemical techniques and was successfully used as catalyst for solvent free oxidation of toluene in the presence of molecular oxygen using batch reactor. The catalytic performance of Pd/ZrO 2 was explored in terms of effect of catalyst loading, reaction time, temperature and partial pressure of oxygen on oxidation of toluene in solvent free conditions. Pd/ZrO 2 was found as a stable catalyst under the reaction conditions. Used catalyst exhibited the same catalytic efficiency as fresh catalyst under similar reaction conditions. Reaction was taking place according to Langmuir-Hinshelwood type of mechanism.

Present study is concerned with the dyeing behavior of gamma irradiated cotton using direct dyes.... more Present study is concerned with the dyeing behavior of gamma irradiated cotton using direct dyes. The fabric and dye powder was exposed to absorbed doses of Cs-137 gamma irradiator between 14 and 26 kGy. It was found that 18 kGy is the optimal absorbed dose for tuning the surface of fabric to get colour strength using Direct

Desalination and Water Treatment, 2015