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Removal of heavy metal ions (HMI) from water streams is desirable due to their toxic and carcinogenic effects. Therefore, this study was conducted to prepare a low cost adsorbent in the form of non-activated carbon (NAC) and activated carbon (AC) using rice husk, a local bio-waste material. Activation of material was performed by base leaching, chemical activation using ZnCl2, followed by acid washing. The initial and final concentrations of HMI in water were measured using Atomic Absorption Spectroscopy. Volatile matter, ash, moisture and surface area of the prepared material were measured using ASTM methods E 897- 88 R04, E 830 - 87 R04, E 949 - 88 R04 and D 1050 - 1 respectively. An enhancement factor was used to evaluate the activating effect of the adsorbent. Maximum % age removal of HMI was measured as 69.0, 64.0, 62.0 and 56% for Ni, Cd, Zn and Pb respectively using NAC. However, by using AC, a significant increase in the %age removal efficiency of HMI was observed and measured as 99.0, 95.5, 93.0 and 89% for Ni, Cd, Zn and Pb respectively. The results showed that AC derived from waste biomass is a simple, ecological and cost-effective approach to remove bulk of metal ions from water and wastewater.

Ionic liquids are regarded as green solvents and found very effective in the pretreatment of biomass and spent wastes. However, the high cost of ionic liquids is a major worry. In this concern, reg...

The main objective of this study is to investigate the effect of solvent, temperature, and stirring on synthesis yield of Ionic Liquids (ILs). A representative Ionic Liquid [BMIM][BF4] is prepared using seven different solvents and their influence on percentage yield is explained using a new correlation; solvent effectiveness factor (SEF). The SEF of solvent is governed by nature of solvent, operating temperature and stirring rate. Acetone has the highest SEF 1.275 and affords maximum IL yield 88.11% while toluene has the least SEF 0.674 and produces minimum IL 63.21%. When synthesis temperature is increased from 50 to 80 °C, synthesis yield is substantially increased from 76.7 to 93.08% because rise in temperature increases the SEF from 1.234 to 1.333, mainly due to the decrease in solvent viscosity. Similarly, when stirring rate is increased from 80 to 200 RPM, IL yield slightly increased from 87.37 to 91.35% due to addition of mechanical energy in the reaction mixture which in turn reduced solvent viscosity and increased SEF from 1.278 to 1.297. Keywords: Ionic Liquids, Synthesis, Solvent effectiveness factor, Viscosity, Boiling point

The demand and importance of fairness creams as a major cosmetic have increased significantly in recent years. However, some of these cosmetics contain heavy metals, hydroquinone and microorganism that can cause various health problems. Therefore, the aim of this study is to determine and examine the concentration of metals (i.e. Cd, Pb, Cr, Ni, Zn, Hg), hydroquinone and microorganisms in nine different fairness creams produced by local and international brands. The health risk assessment of the tested substances for consumers was accessed through systemic exposure dosage (SED), margin of safety (MoS), lifetime cancer risk (LCR), hazard quotient (HQ) and hazard index (HI). The concentration of Zn and Hg were found the highest and measured in the range of 17.82-138.06 mg.kg

Mixed-matrix nanocomposite (PES/CA/PVP) membranes were fabricated for water desalination by incorporating varying amount of titanium dioxide nanoparticles (TiO2 NPs) ranging from 0 and 2 wt. %. Efficient dispersion of nanoparticles within polymeric membranes was achieved using the chemical precipitation method for uniform surface generation, and an asymmetric morphology was achieved via phase inversion method. Finally, membranes were characterized by Fourier Transform Infrared (FTIR) spectroscopy, Thermo Gravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), porosity and contact angle analysis. FTIR confirmed chemical composition of membranes in terms of polymers (PES/CA/PVP) and TiO2. TGA analysis confirmed an increase in thermal stability of membranes with the increase of TiO2 nanoparticles loading. The addition of TiO2 nanoparticles also resulted in an increase in porous structures due to an increase in mean pore size, as shown by SEM results. An increase in the hydrophilicity of the membranes was observed by increasing the concentration of TiO2 nanoparticles. The present study investigated pristine and mixed-matrix nanocomposite NF membrane performance while filtering a NaCl salt solution at varying concentration range (from 1 to 4 g/Lit 6 bar). The prepared membranes demonstrated significant improvement in water permeability and hydrophilicity. Further, to optimize the water flux and salt rejection, the concentration of Polyvinylpyrrolidone (PVP) was optimized along with TiO2 nanoparticles. Both the water flux and salt rejection of the fabricated membranes were observed to increase with an increase inTiO2 nanoparticles to 2 wt. % loading with optimized PVP concentration, which demonstrated the improved desalination performance of resultant membranes.

A highly dirt resistant paint for building facades without chemicals harmful to nature and environment, is developed which resolves the unattractive disfigurement of building walls caused by dirt. The experimentation is scientifically and statistically planned with the aid of computer programming. It consists of a sequence of phases which include the selection of appropriate raw materials, adopting of Basic Language computer programming to generate a target population of paint formulations. The average PVC percentage is computed using theory and found to be 54.98% for the target population of 543143 paint formulations hence verifies the literature results. Experimentation and statistical analysis are performed to compare the classical conventional agitator with latest lab equipment like Nano mill and it is concluded that Nano mill performs better on the average than conventional agitator in preparation of paint formulations. Hence the sample of paint formulations is prepared on Nano mill and tested in laboratory using advanced available technology for the analysis and comparison of paint properties to determine the best paint formulation. The results are analyzed using Analysis Of Variance Technique (ANOVA) and it is concluded that the paint formulation named “O3” has the highest dirt resistance on the average. The final selected formula O3 is compared with three other competitor paints in market under natural environment for a period of almost one year. A regression model is also constructed to study the effect of environmental factors like time, temperature and humidity on dirt resistance of paints. It is found that O3 formulation is the best environment friendly which performs equally well with one competitor paint and has higher dirt resistance than two other competitor paint formulations containing harmful chemicals. The regression model of dirt resistance on variables including time, temperature and humidity shows that these factors are significantly affecting the dirt resistance of a given paint at 5% level of significance. 95.34% variation in the dirt resistance of a given paint is due to and explained by the given factors. The regression model is useful to predict the average dirt resistance of a given paint with a certain level of confidence. The project exemplifies the work of an applied research from conceptualization to successful commercialization for the paint industry.

Algaecides are chemicals that cause serious health problems. Conventional paints contain algaecides to improve the algae resistance on the paint film. Present research has suggested an environment-friendly paint formulation that focuses on developing algae resistance without having algaecides. In this research, algae growth on newly developed paint is modeled by incorporating dirt resistance of paint and natural phenomena including humidity, temperature, and time, respectively. The fitted Model revealed explained variation of 59.65% in the average algae growth, of which, dirt resistance, humidity, temperature, and some of their interactions play significant role in this variation. The model suggests that the proposed newly developed paint without algaecides is more resistant to algae growth and significantly decreased the average algae growth rate by 0.53% as compared to conventional paints. Keeping the effect of all other factors constant, if dirt resistance of paint (Dc value) increases by one percent, average algae growth decreases by 12.98%, when temperature increases by 1 &deg, C, average algae growth decreases by 22.4%, a positive unit change in the joint linear effect of dirt resistance, temperature, and humidity caused a decrease in average algae growth by 0.0031%. It was also observed that the individual effect of the humidity variable was inversely related with average algae growth. However, the combination of humidity and temperature, humidity and dirt resistance, humidity and time, and the quadratic effect of humidity were found to increase the average algae growth rate. The cubic effect of temperature variable by one degree centigrade resulted in decrease of average algae growth by 0.000907%.

Algaecides are chemicals that cause serious health problems. Conventional paints contain algaecides to improve the algae resistance on the paint film. Present research has suggested an environmental friendly paint formulation that focuses on developing algae resistance without having algaecides. In this research, Algae growth on newly developed paint is modeled by incorporating dirt resistance of paint and natural phenomena including humidity, temperature and time respectively. The fitted Model revealed explained variation of 59.65% in the average algae growth, of which, Dirt Resistance, Humidity and temperature and some of their interactions play significant role in this variation. Model suggests that the proposed newly developed paint without algaecides is more resilient to algae growth and significantly decreased the average algae growth rate by 0.53% as compared to conventional paints. Keeping the effect of all other factors constant, if dirt resistance of paint (Dc value) increases by one percent, average algae growth decreases by 12.98%; when temperature increases by 1oC, average algae growth decreases by 22.4%; a positive unit change in the joint linear effect dirt resistance, temperature and humidity caused a decrease in average algae growth by 0.0031%. It was also observed that the individual effect of humidity variable was inversely related with average algae growth. However the combination of humidity and temperature, humidity and dirt resistance, humidity and time, and the quadratic effect of humidity were found to increase the average algae growth rate. The cubic effect of temperature variable by one degree centigrade resulted in decrease of average algae growth by 0.000907%.

Novel polymer matrix composite membranes of cellulose acetate (CA)/polyethylene glycol (PEG) doped with 10–30 wt.% fumed silica particles (FSP) were synthesized. The dissolution casting methodology was used to construct reverse osmosis (RO) membrane which accounts the explicit application for desalination process. The interactions between polymer chains and doped FSP were confirmed by Fourier transform infrared spectroscopy (FTIR). Differential scanning calorimetry thermograms support the physical nature of polymer matrix composite membranes (PMCMs) and an improved glass transition temperature (Tg) from 78.3 to 92.4 °C was observed. The thermal stability of the composite membranes significantly enhanced with the addition of FSP. The typical morphology of PMCM was observed using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The 30 wt.% of FSP filled PMCM showed substantial improvement in tensile strength (8.2 MPa) and Young's modulus (854.0 MPa) as compared to the PMCM without FSP. The percentage water content (WC) of the membrane doped with 30 wt.% FSP absorbed more water as compared to the other membranes. It was also noticed that the FSP doped PMCM enhanced the desalination process which was monitored in terms of permeation flux (L/m2·h) and salt rejection (%). The optimum performance of desalination process was shown by 30 wt.% FSP doped PMCM; the permeation flux was 0.66 L/m2·h and salt rejection was 98.4% for the initial feed of 0.35 wt.% NaCl aqueous solution at 25 °C and operating pressure of 4.0 bar (osmotic pressure 2.9 bar).

A highly dirt-resistant paint for building fa&ccedil, ades without chemicals harmful to nature and the environment would resolve the unattractive disfigurement of building walls caused by dirt. The current ranking of Pakistan in terms of air pollution is 139th. A set of dirt-resistant paint formulae was constructed with the aid of computer programming. From this set, the best dirt-resistant paint formula was explored and identified. The final determination of the optimum formulation was based on statistically planned experiments conducted in the laboratory and in a natural environment. In order to achieve high-quality results, the best available laboratory equipment were used. The results obtained were analyzed and conclusions were drawn using appropriate statistical techniques. The procedure started with the selection of appropriate raw materials and generation of a target population of 543,143 paint formulations by adopting Basic Language computer programming. The average pigment volume concentration (PVC) percentage was computed using theory and found to be 54.98% for the target population paint formulations, verifying the literature results. Experimentation and statistical analysis were performed to compare the classical conventional agitator with the latest lab equipment such as a nano mill, and it was concluded that the nano mill performs better on average than the conventional agitator in the preparation of paint formulations. Hence, the sample of paint formulations was prepared on a nano mill and tested in the laboratory using advanced available technology for the analysis and comparison of paint properties to determine the best paint formulation. The results were analyzed using the Analysis of Variance (ANOVA) technique, and it was concluded that the newly developed paint has the highest dirt resistance on average. The final selected formula, No. 50 (the newly developed paint), was compared with the three best conventional paints available in the Pakistan market in a natural environment for a period of almost one year. A regression model was also constructed to study the effect of environmental factors like time, temperature, and humidity on the dirt resistance of paints. It was found that the newly developed paint formulation is the most environmentally friendly. It performs equally well as one conventional paint and has higher dirt resistance than two other conventional paint formulations containing harmful chemicals. The regression model of dirt resistance involving variables including time, temperature, and humidity shows that these factors significantly affect the dirt resistance of a given paint at a 5% level of significance. For a given paint, 95.34% of the variation in the dirt resistance is due to and explained by the given factors. The regression model is useful for predicting the average dirt resistance of a given paint with a certain level of confidence. The project exemplifies the work of applied research from conceptualization to successful commercialization in the paint industry.

In the present work, thermophysical properties such as density (ρ), dynamic viscosity (η), refractive index (nD), and surface tension (σ) of aqueous piperazine (PZ) solutions with mass fractions (100w = 1.74, 5.16, 10.35) have been measured from temperatures (298.15 to 338.15) K. All of these properties have also been measured for the aqueous blends of N-methyldiethanolamine (MDEA) and piperazine (PZ) with mass fractions {100(w1/w2) = 32.28/1.74, 32.28/5.16, 32.28/10.35, 48.80/1.74, 48.80/5.16, 48.80/10.35)} for the entire temperature range. The limit of PZ solubility in water was measured by the addition of a known quantity of anhydrous PZ (solid crystals) in 20 mL of distilled water at temperatures (278 to 343) K with a regular interval of 5 K. The experimental values of the studied physical properties have been compared with the literature and also correlated as a function of temperature. The coefficients of thermal expansion (αp) values have been calculated from their experimental density data using a...

In batch process scheduling, the introduction of intermediate storage tanks between process stages result in increasing the efficiency and productivity of the process. The main purpose of this is to minimize the process completion time, i.e. makespan. However, it is important to determine the right number and respective locations of the intermediate storage to ensure optimal investment and operational cost. The generally adopted transfer policies for handling intermediate storage tanks in batch processes are unlimited intermediate storage (UIS) and finite intermediate storage (FIS). In this work, new completion time algorithms for UIS and FIS transfer policies are proposed using matrix representation. The objective of the proposed approach is to calculate the makespan for all possible production sequences for given batch product recipes while at the same time determining the number and location of intermediate storage tanks required. With the assumptions that the intermediate storage could be used to store any intermediate product, the method is verified against the Gantt chart method and the results agreed well. A number of different product recipes are analyzed using a developed computer code. This enables the proposed algorithms to produce solution options for large size batch scheduling problems.

Scheduling of batch processes involves various parameters such as batch process recipes, sequence of production and transfer policy for product intermediates. All these parameters directly or indirectly affect the makespan, i.e. completion time of a batch process. The scheduling approaches reported in past literatures mostly refer to the use of complex mathematical models for determining makespan. These models require good understanding in formulating the problem using programming techniques to find the optimal solution. The current work proposes new completion time algorithms for multiproduct batch process with two commonly used transfer policies namely zero wait (ZW) and no intermediate storage (NIS). The batch process recipes are presented in the form of a matrix which is then used to solve for the completion time using developed algorithms. Rearrangement of the matrix rows reflects the changes in production sequences possible for the specified batch process recipes which then enable the makespan to be determined accordingly for the different sequences. Designer is then provided with the production sequence options with their corresponding makespan from which a selection could be made.

In this paper, a comparative study of the treatment of raw and biotreated (upflow anaerobic sludge blanket, UASB) textile dye bath effluent using advanced oxidation processes (AOPs) is presented. The AOPs applied on raw and biotreated textile dye bath effluent, after characterization in terms of COD, colour, BOD and pH, were ozone, UV, UV/H2O2 and photo-Fenton. The decolorization of raw dye bath effluent was 58% in the case of ozonation. However it was 98% in the case of biotreated dye bath effluent when exposed to UV/H2O2. It is, therefore, suggested that a combination of biotreatment and AOPs be adopted to decolorize dye bath effluent in order to make the process more viable and effective. Biodegradability was also improved by applying AOPs after biotreatment of dye bath effluent.

The thermophysical properties of 1-hexyl-3-methyl imidazolium based hydrophobic room temperature ionic liquids (RTILs); with tetrafluoroborate (BF4), hexafluorophosphate (PF6), and bis(trifluoromethylsulfonyl)imide (Tf2N) anions, namely density ρ (298.15 to 348.15) K, dynamic viscosity η (288.2 to 348.2) K, surface tension σ (298.15 to 338) K, and refractive index nD (302.95 to 332.95) K have been measured. The coefficients of thermal expansion αp values were calculated from the experimental density data using an empirical correlation. The thermal stability of all ILs is also investigated at two different heating rates (10 and 20) °C · min−1) using thermogravimetric analyzer (TGA). The experimental results presented in this study reveal that the choice of anion type shows the most significant effect on the properties of ILs. The chloride and water contents of ILs (as impurities) are also investigated and reported in the present work.

Densities (ρ) of pure and aqueous N-methyldiethanolamine (MDEA) solutions (wMDEA = 0.3228 or 4 mol·kg−1 and wMDEA = 0.4880 or 8 mol·kg−1) at (298.15 to 338.15) K were measured at atmospheric pressu...

In this work, physical properties such as dynamic viscosity at (298.15 to 338.15) K, surface tension, and refractive index at temperatures (303.15 to 333.15) K of pure and aqueous N-methyldiethanol...

Thermally-induced phase separation (TIPS) method was used to synthesize polymer matrix (PM) membranes for reverse osmosis from cellulose acetate/polyethylene glycol (CA/PEG300) conjugated with silica nanoparticles (SNPs). Experimental data showed that the conjugation of SNPs changed the surface properties as dense and asymmetric composite structure. The results were explicitly determined by the permeability flux and salt rejection efficiency of the PM-SNPs membranes. The effect of SNPs conjugation on MgSO4 salt rejection was more significant in magnitude than on permeation flux i.e. 2.38 L/m(2)h. FTIR verified that SNPs were successfully conjugated on the surface of PM membrane. DSC of PM-SNPs shows an improved Tg from 76.2 to 101.8 °C for PM and PM-S4 respectively. Thermal stability of the PM-SNPs membranes was observed by TGA which was significantly enhanced with the conjugation of SNPs. The micrographs of SEM and AFM showed the morphological changes and increase in the valley and ridges on membrane surface. Experimental data showed that the PM-S4 (0.4 wt% SNPs) membrane has maximum salt rejection capacity and was selected as an optimal membrane.

In this study pristine multi-walled carbon nanotubes (MWCNTs) were surface engineered (SE) in strong acidic medium by oxidation purification method to form SE-MWCNT. Five different amount of SE-MWCNT ranging from 0.1 to 0.5 wt% were thoroughly and uniformly dispersed in cellulose acetate/polyethylene glycol (CA/PEG400) polymer matrix during synthesis of membrane by dissolution casting method. The structural analysis, surface morphology and roughness was carried out by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and atomic force microscopy (AFM), respectively, which showed that the dispersed SE-MWCNT was substantially tethered in CA/PEG400 polymer matrix membrane. The thermogravimetric analysis (TGA) of membranes also suggested some improvement in thermal properties with the addition of SE-MWCNT. Finally, the performance of these membranes was assessed for suitability in drinking water treatment. The permeation flux and salt rejection were determined by using indigenously fabricated reverse osmosis pilot plant with 1000 ppm NaCl feed solution. The results showed that the tethered SE-MWCNT/CA/PEG400 polymer matrix membrane, with strong SE-MWCNTs/polymer matrix interaction, improved the salt rejection performance of the membrane with the salt rejection of 99.8% for the highest content of SE-MWCNT.

Different vegetable oil based biodiesel (FAMES) were prepared by alkaline transesterification using refined oils as well as waste frying oil (WFO). Methanol and sodium hydroxide are used as catalyst under similar reaction conditions. To ensure the quality of biodiesel produced, a series of different ASTM Standard tests were carried out. In this context, various testwere done including viscosity, carbon residue, specific gravity, corrosion test, flash point, cloud point and pour point. Results revealed that characteristics of biodiesel depend on the feedstock and it is far better than petroleum diesel., {"references":["B. K. Barnwal and M. P. Sharma, \"Prospects of biodiesel production from vegetable oils in India,\" Renewable and Sustainable Energy Reviews, vol. 9, pp. 363-378, 2005.","F. Qiu, et al., \"Biodiesel production from mixed soybean oil and rapeseed oil,\" Applied Energy, vol. 88, pp. 2050-2055, 2011.","Y. Zhang, et al., \"Biodiesel production from waste cooking oil: Economic assessment and sensitivity analysis,\" Bioresource Technology, vol. 90, pp. 229-240, 2003.","A. E. Atabani, et al., \"A comprehensive review on biodiesel as an alternative energy resource and its characteristics,\" Renewable and Sustainable Energy Reviews, vol. 16, pp. 2070-2093, 2012.","G. Huang, et al., \"Biodiesel production by microalgal biotechnology,\" Applied Energy, vol. 87, pp. 38-46, 2010.","Y. C. Sharma and B. Singh, \"Development of biodiesel: Current scenario,\" Renewable and Sustainable Energy Reviews, vol. 13, pp. 1646-1651, 2009.","F. Ma and M. A. Hanna, \"Biodiesel production: a review,\" Bioresource Technology, vol. 70, pp. 1-15, 1999.","P. Felizardo, et al., \"Production of biodiesel from waste frying oils,\" Waste Management, vol. 26, pp. 487-494, 2006."]}

This paper investigates the effect of variable reflux ratio on final product composition in a laboratory scale distillation column. The findings of this study include a minimum reflux ratio at which the highest purity of the product could be achieved. The experimental setup is a Technovate Distillation Column with five sieve plates, a feed tank, a reboiler, and a condenser. The feed and reflux ratio was varied with the help of flow meters associated with two centrifugal pumps. The feed composition was set to 45 percent ethanol-water mixture. The final composition obtained was 95% ethanol in the distillate. The minimum reflux ratio was found to be 60 percent of maximum flow.

The solubility*of carbon dioxide (CO 2 ) in fresh and recycled ionic liquid (IL); 1-hexyl-3-methyl imidazolium tetrafluoroborate [C 6 mim][BF 4 ] was experimentally measured at three different temperatures i.e., 303.15 K, 318.15 K, 333.15 K and pressures up to 60 bar. The solubility of CO 2 and Methane (CH 4 ) in fresh IL; [C 6 mim][BF 4 ] was also measured using binary mixtures of CO 2 and CH 4 i.e., 60/40 (B 64 ) and 40/60 (B 46 ) volume percent at temperatures (303.15 K, 318.15 K, 333.15 K) and pressures up to 60 bar. The solubility measurements for both gases were performed in a specifically designed high pressure miniature gas solubility cell. The solubility of CO 2 and CH 4 in the studied IL increased almost linearly with an increase in pressure and decreased with an increase in temperature and no significant difference was observed for the amount of CO 2 absorbed in fresh and recycled IL at the studied range of operating conditions. It was observed that the presence of CH 4 significantly reduced the solubility of CO 2 in the studied IL.