Batch fermentation of mahula (Madhuca latifolia L., a tree commonly found in tropical rain forest... more Batch fermentation of mahula (Madhuca latifolia L., a tree commonly found in tropical rain forest) flowers was carried out using immobilized cells (in agar agar and calcium alginate) and free cells of Saccharomyces cerevisiae. The ethanol yields were 151.2, 154.5 and 149.1gkg−1 flowers using immobilized (in agar agar and calcium alginate) and free cells, respectively. Cell entrapment in calcium alginate
To meet the issues of energy and environment, algae cultivation for biofuel and CO2sequestration ... more To meet the issues of energy and environment, algae cultivation for biofuel and CO2sequestration is getting popular at the global level. Specific algal strains have been identified for production of biofuel, biomolecules and biomass. To start algae cultivation at lab or industrial scale, it is requirement to have isolated and identified algal culture for targeted products. Water sample for algae from aquatic system is usually consist of mix culture of algae and need to be processed for targeted isolated algal strains using reported techniques like streaking, spraying, serial dilution, and single-cell isolations. But none of these techniques is considered as efficient or popular except streaking on agar plate which involves a set of microbial techniques and may take months to make isolation properly. Here, a new method is proposed to make alginic acid solution using aquatic sample followed by pouring it in calcium chloride solution drop by drop which makes the beads with single or mo...
Rigid cell wall of microalgae is a serious obstacle in commercialization of microalgae biofuels. ... more Rigid cell wall of microalgae is a serious obstacle in commercialization of microalgae biofuels. Conventional cell wall rupturing techniques require organic solvents and are not so efficient. In this research work, TiO2 photocatalyst was used to rupture the cell walls of two different indigenously isolated microalgae strains; Scenedesmus and Chlorella. Cell wall rupturing was monitored by the amount of malondialdehyde (MDA) formed in reaction mixture which is an important secondary metabolite of lipid peroxidation. Different important influencing parameters like calcination temperature, catalyst synthesis pH, catalyst dose, algae media pH, stirring speed and sunlight exposure time were optimized during this study. Maximum MDA concentration of 2.839 nM ml−1 from Scenedesmus and 1.697 nM ml−1 from Chlorella was achieved by using catalyst synthesized at 600 °C calcination temperature and pH 3 by 5 h of sunlight exposure. The synthesized catalyst was immobilized to check out its recycling capability. The catalyst with maximum catalytic activity was characterized by SEM, XRD and FT-IR analysis. Kinetic study for lipid oxidation was also performed and overall study results indicated that TiO2 has good capability to rupture microalgae cell wall for lipid release and this method is cost effective as it does not require the involvement of organic solvents.
Materials Science in Semiconductor Processing, 2019
A-AD) type of small molecule acceptors (M1, M2, M3 and M4) were designed for better optoelectroni... more A-AD) type of small molecule acceptors (M1, M2, M3 and M4) were designed for better optoelectronic properties in organic solar cells. These molecules contain spirobifluorene as a 3D core unit, flanked with 2,1,3-benzothiadiazole (BT) units linked with the end-capped acceptor groups 2-(4-oxo-4,5-dihydrocyclopenta-b-thiophene-6-ylidene)malononitrile (M1), 2-(3-oxo-2,3-dihydro-1H-indene-1-indene-1-ylidene)malononitrile (M2), 2-(5,6-difluoro-3-oxo-2,3-dihydroindene-1-ylidene) malononitrile (M3) and 2-(5,6-dimethyl-3-oxo-2,3-dihydroindene-1-ylidene)malononitrile (M4). The optoelectronic properties of M1-M4 were compared with the well-known reference molecule R, which has the same central BT-spirobifluorene-BT structure as M1-M4 but is end-capped with the 2-(2-dicyanomethylene)-3-ethyl-4oxo-thiazolidin-5-ylidenemethyl group. Among these molecules, M3 has the most appropriate frontier molecular orbital diagram for optoelectronic properties as deduced from MPW1PW91 calculations and also shows the maximum absorption peak at longest wavelength (569 nm) by TD-MPW1PW91 calculations with a polarizable continuum model for chloroform solution. These properties are due to the strong electron-withdrawing endcapped acceptor group which causes a red shift in the absorption spectrum. Computed reorganization energies indicate that the electron mobilities for M1-M4 are higher compared to that of reference R.
Abstract Palm oil mill effluent (POME) was used as an acetonebutanolethanol (ABE) fermentation ... more Abstract Palm oil mill effluent (POME) was used as an acetonebutanolethanol (ABE) fermentation medium using Clostridium saccharoperbutylacetonicum N1-4. Various pretreatment methods were applied on POME to increase the amount of fermentable ...
Background: Kallar Kahar lake, Punjab, Pakistan is a rich source of phytoplankton which can be us... more Background: Kallar Kahar lake, Punjab, Pakistan is a rich source of phytoplankton which can be used for biofuel production. Objective: This study was conducted to investigate the presence of different microalgae species present in this lake and their possible utilization for bioenergy production. Materials and Methods: The crude culture was examined under microscope. Isolation of the identified species was carried out by using serial dilution and colony picking methods. Isolated strains were evaluated by investigating their biomass productivity, salinity resistance and auto-flocculation ability. Results: Four different microalgae species (Chlorella, Scenedesmus, Oscillatoria and Spirulina) were identified in the crude sample. The experimental results indicated that, among the four isolated strains, the Oscillatoria species showed highest biomass productivity (4.2 gL-1) and Scenedesmus showed comparatively higher salt resistance. Scenedesmus also showed great potential of auto-floccu...
There are many types of technologies used to treat wastewater from the industrial and agricultura... more There are many types of technologies used to treat wastewater from the industrial and agricultural effluents. Among them are chemical, physical and biological treatment. Research of microalgae as a solution for wastewater treatment has gained importance in recent years. It is because microalgae require inexpensive substrate which can be found vastly in wastewater, carbon dioxide and solar light. Moreover, microalgae have growth efficiency 10 ~50 times more compared to the terrestrial plant. Present review of biological treatment of wastewater by microalgae only covers municipal and agriculture related to animal manure waste. However, biological treatment by microalgae of palm oil mill effluent (POME) scarcely being reviewed. POME contains organic waste, heavy metal, ammonium, phosphorus etc. which can be assimilated by microalgae for its growth. Previous review shown, microalgae have the capacity to reduce chemical oxygen demand (COD), heavy metal and other substrate value. Addition...
This is an open access article under the terms of the Creative Commons Attribution License, which... more This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
A major factor in practical application of photobioreactors (PBR) is the adhesion of algal cells ... more A major factor in practical application of photobioreactors (PBR) is the adhesion of algal cells onto their inner walls. Optimized algal growth requires an adequate sunlight for the photosynthesis and cell growth. Limitation in light exposure adversely affects the algal biomass yield. The removal of the biofilm from PBR is a challenging and expansive task. This study was designed to develop an inexpensive technique to prevent adhesion of algal biofilm on tubular PBR to ensure high efficiency of light utilization. Rubber balls with surface projections were introduced into the reactor, to remove the adherent biofilm by physical abrasion technique. The floatation of spike balls created a turbulent flow, thereby inhibiting further biofilm formation. The parameters such as, specific growth rate and doubling time of the algae before introducing the balls were 0.451 dayand 1.5 days respectively. Visible biofilm impeding light transmission was formed by 15-20 days. The removal of the biofil...
Currently, the scientific community is keenly working on environmental-friendly processes for the... more Currently, the scientific community is keenly working on environmental-friendly processes for the production of clean energy and sustainable development. The study was conducted to cultivate microalgae in raw institutional wastewater for water treatment, enriched production of biomass and CO 2 sequestration. The strains which were used in this study are Scenedesmus sp. and Chlorella sp. which were isolated from Kallar Kahar Lake, Pakistan. Both strains were cultivated in synthetic growth medium (Bold's Basal Medium) to enhance biomass production. Afterward, microalgae cultures were inoculated in wastewater sample in mixotrophic mode under ambient conditions. The impurities in wastewater were successfully removed from the original sample by the 7th day of operation. COD 95%, nitrate 99.7% and phosphate 80.5% were removed by applying Scenedesmus sp. Meanwhile, Chlorella sp. reduced 84.86% COD, 98.2% nitrate and 70% phosphate, respectively. Interestingly, sulfates were removed from wastewater completely by both strains. Besides being useful in wastewater remediation, these microalgae strains were subsequently harvested for lipid extraction and potential biofuel production was determined. Therefore, the applied method is an environmentally safe, cost-effective and alternative technology for wastewater treatment. Furthermore, the achieved biomass through this process can be used for the production of biofuels.
Palm oil mill effluent from the palm oil processing industry has been documented as a cause of se... more Palm oil mill effluent from the palm oil processing industry has been documented as a cause of severe damages to aquatic systems and a significant increase in greenhouse gases. This study was designed to use electrocoagulation for the pre-treatment of palm oil mill effluent to simultaneously reduce the pollutants and produce hydrogen gas. In this research, response surface methodology was applied to evaluate the effects of the main process parameters (voltage supply, retention time, and the addition of sodium chloride) in removing chemical oxygen demand, turbidity and metals from palm oil mill effluent. Response surface methodology was also applied to optimize the production of hydrogen gas from palm oil mill effluent during the electrocoagulation process. The obtained quadratic regression model has a high variance coefficient (R 2 ) value, which is greater than 85%. The optimal conditions to achieve highly efficient wastewater treatment and maximum hydrogen gas production were determined to be 4 volts, 6 hours retention time, and no added NaCl. At optimal conditions, electrocoagulation was able to remove 42.94% chemical oxygen demand (COD), 83.16% turbidity, 23.62% Fe, 27.56% Mg, and 47.83% Ca. Additionally, the production of hydrogen gas (28.87%) was also achieved, which enhances the cost effectiveness of the process.
Despite being more popular for biofuel, microalgae have gained a lot of attention as a source of ... more Despite being more popular for biofuel, microalgae have gained a lot of attention as a source of biomolecules and biomass for feed purposes. Algae farming can be established using land as well as sea and strategies can be designed in order to gain the products of specific interest in the optimal way. A general overview of the contributions of Algae to meet the requirements of nutrients in animal/aquaculture feed is presented in this study. In addition to its applications in animal/aquaculture feed, algae can produce a number of biomolecules including astaxanthin, lutein, beta-carotene, chlorophyll, phycobiliprotein, Polyunsaturated Fatty Acids (PUFAs), beta-1,3-glucan, and pharmaceutical and nutraceutical compounds which have been reviewed with respect to their commercial importance and current status. The review is further extended to highlight the adequate utilization of value added products in the feeds for livestock, poultry and aquaculture (with emphasis in shrimp farming).
In this study investigation was made to evaluate the effects of different algal media components ... more In this study investigation was made to evaluate the effects of different algal media components to get optimized cell count of Scenedesmus dimorphus. Five different fresh water algal media such as Bold's Basal Medium (BBM), M4N medium, BG-11 medium, N-8 medium and M-8 medium were used for culturing S. dimorphus in flask culture. A set of environmental factors including light, temperature, air flow rate and nutritional components was standardized to obtain the highest productivity of 0.1406 g/L with specific growth rate of 0.10483/day. This study designates the bold basal medium as advantageous one for S. dimorphus and also reveals that production of metabolites by the same algal strain depends mostly on the nature of constituents of media and might have different influence on the pH.
This study was designed to compare the effectiveness of Aluminium (Al) and Iron (Fe) as electrode... more This study was designed to compare the effectiveness of Aluminium (Al) and Iron (Fe) as electrodes to reduce the polluting nature of Palm Oil Mill Effluent (POME) and simultaneous hydrogen production using electrocoagulation (EC). Electrocoagulation of raw POME and anaerobically pretreated POME was performed using Direct Current (DC) electricity of 2.0, 3.0, and 4.0 volts in a reactor volume of 20 liters. The results of raw POME treatment reveal that the chemical oxygen demand (COD) and turbidity was decreased around 57.66% and 62.5%, respectively, using Al electrode. However, the use of iron electrodes could reduce the COD and turbidity of raw POME about 35.3% and 43.10%, respectively. The reduction in polluting factors of the raw POME was accompanied with the production of 42% and 22.8% of hydrogen gas concentration using Al and Fe electrodes, respectively. On the other hand, the results of Electrocoagulation of POME which was pretreated in anaerobic pond show that the COD was dec...
Batch fermentation of mahula (Madhuca latifolia L., a tree commonly found in tropical rain forest... more Batch fermentation of mahula (Madhuca latifolia L., a tree commonly found in tropical rain forest) flowers was carried out using immobilized cells (in agar agar and calcium alginate) and free cells of Saccharomyces cerevisiae. The ethanol yields were 151.2, 154.5 and 149.1gkg−1 flowers using immobilized (in agar agar and calcium alginate) and free cells, respectively. Cell entrapment in calcium alginate
To meet the issues of energy and environment, algae cultivation for biofuel and CO2sequestration ... more To meet the issues of energy and environment, algae cultivation for biofuel and CO2sequestration is getting popular at the global level. Specific algal strains have been identified for production of biofuel, biomolecules and biomass. To start algae cultivation at lab or industrial scale, it is requirement to have isolated and identified algal culture for targeted products. Water sample for algae from aquatic system is usually consist of mix culture of algae and need to be processed for targeted isolated algal strains using reported techniques like streaking, spraying, serial dilution, and single-cell isolations. But none of these techniques is considered as efficient or popular except streaking on agar plate which involves a set of microbial techniques and may take months to make isolation properly. Here, a new method is proposed to make alginic acid solution using aquatic sample followed by pouring it in calcium chloride solution drop by drop which makes the beads with single or mo...
Rigid cell wall of microalgae is a serious obstacle in commercialization of microalgae biofuels. ... more Rigid cell wall of microalgae is a serious obstacle in commercialization of microalgae biofuels. Conventional cell wall rupturing techniques require organic solvents and are not so efficient. In this research work, TiO2 photocatalyst was used to rupture the cell walls of two different indigenously isolated microalgae strains; Scenedesmus and Chlorella. Cell wall rupturing was monitored by the amount of malondialdehyde (MDA) formed in reaction mixture which is an important secondary metabolite of lipid peroxidation. Different important influencing parameters like calcination temperature, catalyst synthesis pH, catalyst dose, algae media pH, stirring speed and sunlight exposure time were optimized during this study. Maximum MDA concentration of 2.839 nM ml−1 from Scenedesmus and 1.697 nM ml−1 from Chlorella was achieved by using catalyst synthesized at 600 °C calcination temperature and pH 3 by 5 h of sunlight exposure. The synthesized catalyst was immobilized to check out its recycling capability. The catalyst with maximum catalytic activity was characterized by SEM, XRD and FT-IR analysis. Kinetic study for lipid oxidation was also performed and overall study results indicated that TiO2 has good capability to rupture microalgae cell wall for lipid release and this method is cost effective as it does not require the involvement of organic solvents.
Materials Science in Semiconductor Processing, 2019
A-AD) type of small molecule acceptors (M1, M2, M3 and M4) were designed for better optoelectroni... more A-AD) type of small molecule acceptors (M1, M2, M3 and M4) were designed for better optoelectronic properties in organic solar cells. These molecules contain spirobifluorene as a 3D core unit, flanked with 2,1,3-benzothiadiazole (BT) units linked with the end-capped acceptor groups 2-(4-oxo-4,5-dihydrocyclopenta-b-thiophene-6-ylidene)malononitrile (M1), 2-(3-oxo-2,3-dihydro-1H-indene-1-indene-1-ylidene)malononitrile (M2), 2-(5,6-difluoro-3-oxo-2,3-dihydroindene-1-ylidene) malononitrile (M3) and 2-(5,6-dimethyl-3-oxo-2,3-dihydroindene-1-ylidene)malononitrile (M4). The optoelectronic properties of M1-M4 were compared with the well-known reference molecule R, which has the same central BT-spirobifluorene-BT structure as M1-M4 but is end-capped with the 2-(2-dicyanomethylene)-3-ethyl-4oxo-thiazolidin-5-ylidenemethyl group. Among these molecules, M3 has the most appropriate frontier molecular orbital diagram for optoelectronic properties as deduced from MPW1PW91 calculations and also shows the maximum absorption peak at longest wavelength (569 nm) by TD-MPW1PW91 calculations with a polarizable continuum model for chloroform solution. These properties are due to the strong electron-withdrawing endcapped acceptor group which causes a red shift in the absorption spectrum. Computed reorganization energies indicate that the electron mobilities for M1-M4 are higher compared to that of reference R.
Abstract Palm oil mill effluent (POME) was used as an acetonebutanolethanol (ABE) fermentation ... more Abstract Palm oil mill effluent (POME) was used as an acetonebutanolethanol (ABE) fermentation medium using Clostridium saccharoperbutylacetonicum N1-4. Various pretreatment methods were applied on POME to increase the amount of fermentable ...
Background: Kallar Kahar lake, Punjab, Pakistan is a rich source of phytoplankton which can be us... more Background: Kallar Kahar lake, Punjab, Pakistan is a rich source of phytoplankton which can be used for biofuel production. Objective: This study was conducted to investigate the presence of different microalgae species present in this lake and their possible utilization for bioenergy production. Materials and Methods: The crude culture was examined under microscope. Isolation of the identified species was carried out by using serial dilution and colony picking methods. Isolated strains were evaluated by investigating their biomass productivity, salinity resistance and auto-flocculation ability. Results: Four different microalgae species (Chlorella, Scenedesmus, Oscillatoria and Spirulina) were identified in the crude sample. The experimental results indicated that, among the four isolated strains, the Oscillatoria species showed highest biomass productivity (4.2 gL-1) and Scenedesmus showed comparatively higher salt resistance. Scenedesmus also showed great potential of auto-floccu...
There are many types of technologies used to treat wastewater from the industrial and agricultura... more There are many types of technologies used to treat wastewater from the industrial and agricultural effluents. Among them are chemical, physical and biological treatment. Research of microalgae as a solution for wastewater treatment has gained importance in recent years. It is because microalgae require inexpensive substrate which can be found vastly in wastewater, carbon dioxide and solar light. Moreover, microalgae have growth efficiency 10 ~50 times more compared to the terrestrial plant. Present review of biological treatment of wastewater by microalgae only covers municipal and agriculture related to animal manure waste. However, biological treatment by microalgae of palm oil mill effluent (POME) scarcely being reviewed. POME contains organic waste, heavy metal, ammonium, phosphorus etc. which can be assimilated by microalgae for its growth. Previous review shown, microalgae have the capacity to reduce chemical oxygen demand (COD), heavy metal and other substrate value. Addition...
This is an open access article under the terms of the Creative Commons Attribution License, which... more This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
A major factor in practical application of photobioreactors (PBR) is the adhesion of algal cells ... more A major factor in practical application of photobioreactors (PBR) is the adhesion of algal cells onto their inner walls. Optimized algal growth requires an adequate sunlight for the photosynthesis and cell growth. Limitation in light exposure adversely affects the algal biomass yield. The removal of the biofilm from PBR is a challenging and expansive task. This study was designed to develop an inexpensive technique to prevent adhesion of algal biofilm on tubular PBR to ensure high efficiency of light utilization. Rubber balls with surface projections were introduced into the reactor, to remove the adherent biofilm by physical abrasion technique. The floatation of spike balls created a turbulent flow, thereby inhibiting further biofilm formation. The parameters such as, specific growth rate and doubling time of the algae before introducing the balls were 0.451 dayand 1.5 days respectively. Visible biofilm impeding light transmission was formed by 15-20 days. The removal of the biofil...
Currently, the scientific community is keenly working on environmental-friendly processes for the... more Currently, the scientific community is keenly working on environmental-friendly processes for the production of clean energy and sustainable development. The study was conducted to cultivate microalgae in raw institutional wastewater for water treatment, enriched production of biomass and CO 2 sequestration. The strains which were used in this study are Scenedesmus sp. and Chlorella sp. which were isolated from Kallar Kahar Lake, Pakistan. Both strains were cultivated in synthetic growth medium (Bold's Basal Medium) to enhance biomass production. Afterward, microalgae cultures were inoculated in wastewater sample in mixotrophic mode under ambient conditions. The impurities in wastewater were successfully removed from the original sample by the 7th day of operation. COD 95%, nitrate 99.7% and phosphate 80.5% were removed by applying Scenedesmus sp. Meanwhile, Chlorella sp. reduced 84.86% COD, 98.2% nitrate and 70% phosphate, respectively. Interestingly, sulfates were removed from wastewater completely by both strains. Besides being useful in wastewater remediation, these microalgae strains were subsequently harvested for lipid extraction and potential biofuel production was determined. Therefore, the applied method is an environmentally safe, cost-effective and alternative technology for wastewater treatment. Furthermore, the achieved biomass through this process can be used for the production of biofuels.
Palm oil mill effluent from the palm oil processing industry has been documented as a cause of se... more Palm oil mill effluent from the palm oil processing industry has been documented as a cause of severe damages to aquatic systems and a significant increase in greenhouse gases. This study was designed to use electrocoagulation for the pre-treatment of palm oil mill effluent to simultaneously reduce the pollutants and produce hydrogen gas. In this research, response surface methodology was applied to evaluate the effects of the main process parameters (voltage supply, retention time, and the addition of sodium chloride) in removing chemical oxygen demand, turbidity and metals from palm oil mill effluent. Response surface methodology was also applied to optimize the production of hydrogen gas from palm oil mill effluent during the electrocoagulation process. The obtained quadratic regression model has a high variance coefficient (R 2 ) value, which is greater than 85%. The optimal conditions to achieve highly efficient wastewater treatment and maximum hydrogen gas production were determined to be 4 volts, 6 hours retention time, and no added NaCl. At optimal conditions, electrocoagulation was able to remove 42.94% chemical oxygen demand (COD), 83.16% turbidity, 23.62% Fe, 27.56% Mg, and 47.83% Ca. Additionally, the production of hydrogen gas (28.87%) was also achieved, which enhances the cost effectiveness of the process.
Despite being more popular for biofuel, microalgae have gained a lot of attention as a source of ... more Despite being more popular for biofuel, microalgae have gained a lot of attention as a source of biomolecules and biomass for feed purposes. Algae farming can be established using land as well as sea and strategies can be designed in order to gain the products of specific interest in the optimal way. A general overview of the contributions of Algae to meet the requirements of nutrients in animal/aquaculture feed is presented in this study. In addition to its applications in animal/aquaculture feed, algae can produce a number of biomolecules including astaxanthin, lutein, beta-carotene, chlorophyll, phycobiliprotein, Polyunsaturated Fatty Acids (PUFAs), beta-1,3-glucan, and pharmaceutical and nutraceutical compounds which have been reviewed with respect to their commercial importance and current status. The review is further extended to highlight the adequate utilization of value added products in the feeds for livestock, poultry and aquaculture (with emphasis in shrimp farming).
In this study investigation was made to evaluate the effects of different algal media components ... more In this study investigation was made to evaluate the effects of different algal media components to get optimized cell count of Scenedesmus dimorphus. Five different fresh water algal media such as Bold's Basal Medium (BBM), M4N medium, BG-11 medium, N-8 medium and M-8 medium were used for culturing S. dimorphus in flask culture. A set of environmental factors including light, temperature, air flow rate and nutritional components was standardized to obtain the highest productivity of 0.1406 g/L with specific growth rate of 0.10483/day. This study designates the bold basal medium as advantageous one for S. dimorphus and also reveals that production of metabolites by the same algal strain depends mostly on the nature of constituents of media and might have different influence on the pH.
This study was designed to compare the effectiveness of Aluminium (Al) and Iron (Fe) as electrode... more This study was designed to compare the effectiveness of Aluminium (Al) and Iron (Fe) as electrodes to reduce the polluting nature of Palm Oil Mill Effluent (POME) and simultaneous hydrogen production using electrocoagulation (EC). Electrocoagulation of raw POME and anaerobically pretreated POME was performed using Direct Current (DC) electricity of 2.0, 3.0, and 4.0 volts in a reactor volume of 20 liters. The results of raw POME treatment reveal that the chemical oxygen demand (COD) and turbidity was decreased around 57.66% and 62.5%, respectively, using Al electrode. However, the use of iron electrodes could reduce the COD and turbidity of raw POME about 35.3% and 43.10%, respectively. The reduction in polluting factors of the raw POME was accompanied with the production of 42% and 22.8% of hydrogen gas concentration using Al and Fe electrodes, respectively. On the other hand, the results of Electrocoagulation of POME which was pretreated in anaerobic pond show that the COD was dec...
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