Asim Yaqub

Applications of sonoelectrochemistry in wastewater treatment system

Abstract Sonoelectrochemistry is a combination of ultrasound plus electrochemical process. It appears to be an attractive option to treat the industrial wastewater. In this study, we review the several applications of this hybrid technique and their efficiencies for the treatment of a variety of industrial effluents including chemical and dyes, metal-contaminated waters, and its effects on mass transfer in electrochemical process.

Electrochemical Degradation of Polycyclic Aromatic Hydrocarbons in Synthetic Solution and Produced Water Using a Ti/SnO2-Sb2O5-RuO2 Anode

AbstractElectrochemical-oxidation experiments was conducted for degradation of 16 priority polycyclic aromatic hydrocarbons (PAHs) using a dimensionally stable anode (DSA)-type Ti/SnO2-Sb2O5-RuO2 electrode. In the research reported in this paper, for electrooxidation, anode was coated with metal oxides SnO2, Sb2O5, and RuO2 in laboratory using titanium as substrate dip coating thermal decomposition method. Laboratory-scale batch reactor was used for degradation studies at pH 3, 6, and 9. Surface morphology and composition of the anode coatings were characterized by variable pressure field emission scanning electron microscopy and energy dispersive X-ray spectroscopy, respectively. Coating microstructure was analyzed by X-ray diffraction. Stability of coating was analyzed by Raman spectroscopy. Gas chromatography–mass spectrometry results revealed that almost 80, 73, and 82% PAHs removal was found without using electrolyte at pH 3, 6, and 9, respectively. While using electrolyte removal efficiency gone to ...

Characterization of Toxic Metals in Tobacco, Tobacco Smoke, and Cigarette Ash from Selected Imported and Local Brands in Pakistan

In this study, concentrations of Cd, Ni, Pb, and Cr were determined in tobacco, tobacco smoke-condensate, and cigarette ash for selected brands used in Pakistan. Smoking apparatus was designed for metal extraction from cigarette smoke. Samples were digested through microwave digester and then analyzed by flame atomic absorption spectrophotometer (FAAS). Higher concentration of Ni was detected in imported brands than the counterparts in the local brands. Pb levels were however higher in local brands while significant concentration of Cd was observed in both brands. For Cr, the level in tobacco of local brands was higher than their emitted smoke, whereas imported brands showed higher level in smoke than in tobacco. The cigarette ash retained 65 to 75% of the metal and about 25 to 30% went into the body. While this study revealed the serious requirement to standardize the manufacturing of tobacco products, more importantly is the urgent need for stronger enforcements to put in place to alert the general population about the hazardous effects of cigarettes and the health risks associated with these toxic metals.

Electrochemical degradation of petroleum hydrocarbons (PAHS) from synthetic aqueous solutions

Water separated from crude oil and wastewater discharge from petroleum oil refineries contains significant quantity of dissolved hydrocarbons. Polycyclic aromatic hydrocarbons (PAHs) are major toxicants in wastewater of refineries. It is difficult to treat wastewater containing PAHs due to their recalcitrant property and low solubility. Conventional techniques for the treatment of wastewater are still a concern of toxicity. Electrochemical oxidation process has been found to be a favorable for treating wastewater. Electrodes with high stability and electrocatalytic activity are important factors for a successful electrochemical oxidation of toxic organics in wastewater. In this study titanium anodes were coated with tin, antimony and iridium oxide mixture from their respective salts by thermal decomposition method. FESEM and XRD used for surface characterization of Ti/SnO2–Sb2O5–IrO2 anode. Quantification of PAHs was done using GC–MS. Results confirm the presence of respective oxides on anode surface. Their electrocatalytic capability was tested for degradation of 16 priority PAHs in aqueous solution. Results reveal the complete degradation of naphthalene, acenaphthylene, acenaphthene and fluorene without using NaCl electrolyte. While in the presence of NaCl naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene and pyrene were completely removed. About 98% of total PAHs removal was found at all initial pH values 3, 6, and 9 in the presence of electrolyte. Current study will be helpful in improving quality of petroleum industry wastewater containing PAHs.

Preparation of Ti/IrO2 Anode with Low Iridium Content by Thermal Decomposition Process: Electrochemical removal of organic pollutants in water

Abstract In this study IrO2 (Iridium oxide) was coated onto a titanium plate anode from a dilute (50 mg/10 ml) IrCl3×H2O salt solution. Coating was done at high temperature (550∘C) using thermal decomposition. Surface morphology and characteristics of coated surface of Ti/IrO2 anode were examined by FESEM and XRD. The coated anode was applied for electrochemical removal of organic pollutants from synthetic water samples in 100 mL compartment of batch electrochemical cell. About 50% COD removal was obtained at anode prepared with low Ir content solution while 72% COD removal was obtained with anode prepared at high Ir content. Maximum COD removal was obtained at 10 mA/cm2 current density.

Preparation of Ti/TiO2 Anode for Electrochemical Oxidation of Toxic Priority Pollutants

In present study, Ti/TiO2 anodes were prepared in laboratory for degradation of polycyclic aromatic hydrocarbons. Polycyclic aromatic hydrocarbons considered as priority pollutants because of their carcinogenetic properties. PAHs were electrochemically oxidized under galvanostatic conditions using TiO2 coated Ti anode. A synthetic solution containing 16 priority PAHs were prepared in the lab. Surface morphology showed cracked mud structure of coated Ti/TiO2 surface. All the PAHs were efficiently oxidized and degraded from solution. About 96.87% of ƩPAHs were removed in five hours from the bulk solution. The results showed the potential of electrochemical process with Ti/TiO2 anode as a possible and reliable technique for the degradation of PAHs in water.

Polycyclic aromatic hydrocarbons removal from produced water by electrochemical process optimization

Abstract Produced water is actually the wastewater separated from petroleum crude oil. Electrochemical-oxidation experiments was conducted for degradation of 16 priority polycyclic aromatic hydrocarbons (PAHs) using DSA type Ti/IrO2 anode. Laboratory scale batch reactor was used for degradation studies. To get the maximum PAHs removal electrochemical process optimized on three independent variable current density, pH and electrolysis time. The response surface modelling (RSM) based on a Box-Behnken design was applied to get appropriate experimental design. X1, X2 and X3 are the coded factors of independent variables such as the current density, pH and electrolysis time, respectively. Maximum removal was 95.29% at optimized conditions such as current density of 9 mA/cm2, pH 3 and electrolysis time 3.7 h. Quadratic model was suggested best fit model. The results of the Analysis of Variances (ANOVA) for PAHs demonstrated that the model was highly significant.