Drastic threat to the natural system is caused by the uncontrolled release of synthetic pollutant... more Drastic threat to the natural system is caused by the uncontrolled release of synthetic pollutants, including azo dyes. This study centered on the decolorization and biodegradation of water soluble azo dye reactive blue (RB) in a batch mode sequential anaerobic-aerobic processes. A local sewage treatment plant was the source where activated sludge was collected to be used as non-adapted mixed culture with both free and the alginate immobilized cells for RB biodegradation. Under anaerobic conditions, the free and immobilized mixed cells were proved to completely decolorize 10 mg/ L of RB within 20 and 30 h, respectively. Alginateimmobilized mixed cells, resulted in 88%, 87%, and 87% maximum COD removals with samples containing RB at initial concentration of 10, 20, and 40 mg/L, respectively. UV-vis spectra showed the biological cleavage of the azo bond in the anaerobic phase. Estimation of the phytotoxicity of the degraded metabolites suggested that the non-adapted immobilized mixed bacterial cells successfully detoxified RB azo dye.
The ability of pulverized walnut-shell to remove oil from aqueous solutions has been studied. It ... more The ability of pulverized walnut-shell to remove oil from aqueous solutions has been studied. It involves two-phase process which consists of using walnut-shell as a filtering bed for the accumulation and adsorption of oil onto its surface. Up to 96% oil removal from synthetic wastewater samples was achieved while tests results showed that 75% of oil can be removed from the actual wastewater discharged from Al- Duara refinery in the south of Baghdad.
In recent years and decades, there is a great need for developing new alternative energy sources ... more In recent years and decades, there is a great need for developing new alternative energy sources or renewable sustainable energy. On the other hand, new technology approaches are growing . towards benefits from the valuable nutrients in wastewater which are unrecoverable by traditional wastewater treatment processes. In the current study, a novel integrated system of microbial fuel cell and anoxic bioreactor (MFC-ANB) was designed and constructed to investigate its potential for slaughterhouses wastewater treatment, nitrogen recovery, and power generation. The system consisted of a double-chamber tubular type MFC with biocathode inoculated with freshly collected activated sludge. The MFC-ANB system was continuously fed with real-field slaughterhouse wastewater, with initial concentrations of COD and ammonium were 990 mg/L and 200 mg-N/L, respectively. The MFC-ANB system was operated for a total period of 43 days. Maximum removal efficiencies of COD, ammonium, nitrate, nitrogen reco...
This study aimed to investigate the effect of total suspended solids (TSS) on the performance of ... more This study aimed to investigate the effect of total suspended solids (TSS) on the performance of a continuously operated dual-chamber microbial fuel cell (MFC) proceeded by primary clarifier to treat actual potato chips processing wastewater. The system was also tested in the absence of the primary clarifier and the results demonstrated a significant effect of TSS on the polarization curve of the MFC which was obtained by operating the graphite anodic electrode against Ag/AgCl reference electrode. The maximum observed power and current densities were decreased form 102.42 mW/m2 and 447.26 mA/m2 to 80.16 mW/m2 and 299.10 mA/m2, respectively due to the adverse effect of TSS. Also, the internal resistance increased from 40 to 70Ω.
In this study, a dual-chamber microbial fuel cell (MFC) fed with actual potato chips' processing ... more In this study, a dual-chamber microbial fuel cell (MFC) fed with actual potato chips' processing wastewater (PCPW) was tested as a biosensor. The performance of MFC-based biosensor was evaluated in terms of the current measurement range, toxicity detection and sensitivity, and the operational stability. The results revealed that the MFC can simply be converted to an online biosensor unit to detect the harmful effect of suspended solids and acidic content in the actual PCPW on the anodic attached biofilm and the values of the generated current as well. A notable decrease in the current values was observed indicating the adverse effects of the harmful matters in the PCPW fed to the biosensor unit. The results proposed a competition between the harmful components and the favorable substrate in binding to the redox complex. An excellent fitting was obtained between the experimental and predicted results by I K m model with determination coefficient (R 2) and mean-squareerror values of 0.927 and 0.363, respectively. Additionally, a new approach was developed based on direct measurement of actual field data to replace the conventional statistical methods.
This study aimed to investigate the feasibility of treatment actual potato chips processing waste... more This study aimed to investigate the feasibility of treatment actual potato chips processing wastewater in a continuously operated dual chambers microbial fuel cell (MFC) inoculated with anaerobic sludge. The results demonstrated significant removal of COD and suspended solids of more than 99% associated with relatively high generation of current and power densities of 612.5 mW/m3 and 1750 mA/m3, respectively at 100 Ω external resistance.
This study aimed to investigate the performance of microbial fuel cell (MFC) for simultaneous bio... more This study aimed to investigate the performance of microbial fuel cell (MFC) for simultaneous bioremediation of slaughterhouse wastewater and sustainable power generation. For the first time, an integrated system of tubular type microbial fuel cell (MFC) was used in this study. The MFC consisted of three concentric Plexiglas tubes; the inner tube was the anaerobic anodic compartment, the mid tube was the aerobic biocathodic chamber, and the outer tube act as an aerobic bioreactor for extended nitrification process. The MFC system was connected to a complementary external anaerobic bioreactor for denitrification process. The microbial fuel cell was inoculated with freshly collected activated sludge and was continuously fueled with simulated slaughterhouse wastewater. Results revealed that the removal efficiency of the chemical oxygen demand (COD) was up to 99%, and the power generation was 165 mW/m 2 . Also, results demonstrated that maximum removal of NO3 via the denitrification pro...
In this study, a novel application of lab-scale dual chambered air-cathode microbial fuel cell (M... more In this study, a novel application of lab-scale dual chambered air-cathode microbial fuel cell (MFC) has been developed for simultaneous bio-treatment of real pharmaceutical wastewater and renewable electricity generation. The microbial fuel cell (MFC) was provided with zeolite-packed anodic compartment and a cation exchange membrane (CEM) to separate the anode and cathode. The performance of the proposed MFC was evaluated in terms of COD removal and power generation based on the activity of the bacterial consortium in the biofilm mobilized on zeolite bearer. The MFC was fueled with real pharmaceutical wastewater having an initial COD concentration equal to 800 mg/L and inoculated with anaerobic aged sludge. Results demonstrated that the COD removal efficiency, power density and current density were 66%, 2.4 mW/m2 and 10 mA/m2, respectively.
A new bio-electrochemical system was proposed for simultaneous removal of organic matters and sal... more A new bio-electrochemical system was proposed for simultaneous removal of organic matters and salinity from actual domestic wastewater and synthetically prepared saline water, respectively. The performance of a three-chambered microbial osmotic fuel cell (MOFC) provided with forward osmosis (FO) membrane and cation exchange membrane (CEM) was evaluated with respect to the chemical oxygen demand (COD) removal from wastewater, electricity generation, and desalination of saline water. The MOFC wasinoculated with activated sludge and fueled with actual domestic wastewater. Results revealed that maximum removal efficiency of COD from wastewater, TDS removal efficiency from saline water, power density, and current density were 96%, 90%, 30.02 mW/m2, and 107.20 mA/m2, respectively.
Advances in Science and Technology Research Journal
This study investigated the potential of biogas recovery from refinery oily sludge (ROS) inoculat... more This study investigated the potential of biogas recovery from refinery oily sludge (ROS) inoculated with animals' manure by co-digestion of in lab-scale biodigesters at mesophilic conditions. Cow dung (CD), cattle manure (CM), and poultry manure (PM) were utilized as co-substrates. The biogas production from the co-digestion process exceeds its production from uninoculated ROS by approximately 67.5, 22.13 and 21.6% for PM, CM, and CD, respectively. Kinetics of the co-digestion process was well described by the modified Gompertz model. The predicted and experimental values of biogas production were well fitted with R 2 > 0.96, suggesting favorable conditions of the digestion process. New approach for recycling the residual digestate to replace freshwater in concrete mixes was carried out. Results of examining the mechanical properties of the residual digestate-modified concrete mixes demonstrated a potential sustainable approach for the disposal of residual digestate in concrete mixes.
Cell immobilization has been proven to offer noticeable benefits over conventional biological sys... more Cell immobilization has been proven to offer noticeable benefits over conventional biological systems using free cells, particularly for recalcitrant compounds. In this study, mixed bacterial cells were alternatively immobilized in sodium alginate (SA) and in sodium alginate-polyvinyl alcohol (SA-PVA) for biodegradation of sodium dodecyl sulfate (SDS). Synthetically prepared SDS-bearing aqueous solution (SWW), as well as actual automobile service station wastewater (AWW) and laundry wastewater (LWW) were used. The results revealed that high removal efficiencies were achieved after 48 h for both types of beads. When SDS concentration in SWW increased from 10 to 1000 mg L-1 , SDS degradation using both types of beads were decreased from 99.71 % to 85.12 % using SA beads, and from 99.63 % to 83.29 % using SA-PVA beads. The removal efficiency of SDS in the actual (AWW) were 94.91 % and 93.82 % using SA beads and SA-PVA beads, respectively. While, for SDS-bearing laundry (LWW), the removal efficiencies were 94.39 % and 92.04 % using SA beads and SA-PVA beads, respectively. No decline in the biodegradation capacity of immobilized consortium was noted over its recycling and reuse. Both hydrogel matrices lasted for up to five cycles in the actual wastewaters. These promising results confirmed the validity of using immobilized mixed cells as an efficient and cost-effective approach for SDS biodegradation in real industrial wastewaters.
Biodegradation is an environmentally friendly and cost-effective alternative that proved to be ef... more Biodegradation is an environmentally friendly and cost-effective alternative that proved to be efficient for the removal of toxic phenol compounds from aqueous solutions. However, it has been reported that phenol is inhibitory to bacterial growth at concentrations above 0.05 g/L. This study was undertaken to study the degradation of phenol at initial concentrations of 20 mg/L by Bacillus cells individually immobilized in two different matrices including polyvinyl alcohol-sodium alginate (PVA-SA) and polyvinyl alcohol-guar gum (PVA-GG). Results of batch experiments demonstrated that complete removal of phenol was obtained using immobilized cells in the first cycle after 270 and 300 min using cells immobilized in PVA-SA and PVA-GG. Additional cycles were conducted to evaluate the validity of recycling the beads of immobilized cells for phenol biodegradation. Results revealed that the phenol percentage removals were 96, 90, 83, and 75% for the second, third, fourth, and fifth cycles, r...
Metals and plastics waste materials create serious environmental problems, mainly owing to the in... more Metals and plastics waste materials create serious environmental problems, mainly owing to the inconsistency of the wastes streams. The purpose of this paper is to evaluate the possibility of using mixed iron filings and granulated plastic waste materials simultaneously to partially substitute the fine aggregate in concrete composites. Type I Portland cement was mixed with the aggregates to produce the concrete composites. Three weight fractions (30, 40, and 50%) of iron filings waste aggregate were used with 5% of granulated plastic waste. The slump, compressive and flexural strengths as well as the fresh and hard density of the concrete mixtures were determined. The results of the mechanical properties were analyzed in comparison to the control specimens. The main findings of this investigation revealed that the mixture of iron filings and plastic waste materials could be used successfully as partial substitutes of sand in concrete composites. Increasing the granulated plastic was...
International Journal of Energy, Environment and Economics
Anaerobic digestion is a technology widely used for treatment of organic waste to enhance biogas ... more Anaerobic digestion is a technology widely used for treatment of organic waste to enhance biogas recovery. In this study, recycling of date palm wastes (DPWs) was examined as a source for biogas production. The effects of inoculum addition, pretreatment of substrate, and temperature on the biogas production were investigated in batch mode digesters. Results revealed that the effect of inoculum addition was more significant than alkaline pretreatment of raw waste materials. The biogas recovery from inoculated DPWs exceeds its production from DPWs without inoculation by approximately 140% at mesophilic conditions. Whereby, the increase of biogas recovery from pretreated DPWs was 52% higher than its production from untreated DPWs at mesophilic conditions. The thermophilic conditions improved the biogas yield by approximately 23%. The kinetic of bio-digestion process was well described by modified Gompertz model and the experimental and predicted values of biogas production were fitted well with correlation coefficient values > 0.96 suggesting favorable conditions of the process.
Industrial activities in Iraq are associated with significant amounts of non-biodegradable solid ... more Industrial activities in Iraq are associated with significant amounts of non-biodegradable solid waste, waste plastic being among the most prominent. This study involved 86 experiments and 254 tests to determine the efficiency of reusing waste plastic in the production of concrete. Thirty kilograms of waste plastic of fabriform shapes was used as a partial replacement for sand by 0%, 10%, 15%, and 20% with 800 kg of concrete mixtures. All of the concrete mixtures were tested at room temperature. These tests include performing slump, fresh density, dry density, compressive strength, flexural strength, and toughness indices. Seventy cubes were molded for compressive strength and dry density tests, and 54 prisms were cast for flexural strength and toughness indices tests. Curing ages of 3, 7, 14, and 28 days for the concrete mixtures were applied in this work. The results proved the arrest of the propagation of micro cracks by introducing waste plastic of fabriform shapes to concrete mixtures. This study insures that reusing waste plastic as a sand-substitution aggregate in concrete gives a good approach to reduce the cost of materials and solve some of the solid waste problems posed by plastics.
In this study, electricity generation integrated with organic substrate biodegradation was invest... more In this study, electricity generation integrated with organic substrate biodegradation was investigated in a continuous mediator-less microbial fuel cell with graphite electrodes and a selective type of membrane separating the anodic and cathodic compartments of MFC from each other. The performance of MFC was evaluated to treat actual domestic wastewater using aged anaerobic sludge. Results revealed that COD and BOD removal efficiencies were up to 88% and 75%, respectively. At an external resistance value of 100 Ω, a maximum power and current values of 318 mV and 3.11 mA, respectively were obtained.
Microbial fuel cells (MFCs) have the potential to simultaneously treat wastewater for reuse and t... more Microbial fuel cells (MFCs) have the potential to simultaneously treat wastewater for reuse and to generate electricity. This study mainly considers the performance of an upflow dual-chambered MFC continuously fueled with actual domestic wastewater and alternatively biocatalyzed with aerobic activated sludge and strain ofBacillus Subtilis. The behavior of MFCs during initial biofilm growth and characterization of anodic biofilm were studied. After 45 days of continuous operation, the biofilms on the anodic electrode were well developed. The performance of MFCs was mainly evaluated in terms of COD reductions and electrical power output. Results revealed that the COD removal efficiency was 84% and 90% and the stabilized power outputs were clearly observed achieving a maximum value of 120 and 270 mW/m2obtained for MFCs inoculated with mixed cultures andBacillus Subtilisstrain, respectively.
The performance of a membrane-less microbial fuel cell (ML-MFC) was evaluated to treat actual dom... more The performance of a membrane-less microbial fuel cell (ML-MFC) was evaluated to treat actual domestic wastewater. A novel application of inexpensive acrylic beads was examined to separate the anodic and cathodic compartments. The ML-MFC was alternatively inoculated with activated sludge and anaerobic aged sludge. Results revealed that the removal efficiencies of COD and BOD from actual wastewater were 79 and 60%, respectively, using the activated sludge as inoculum. Higher removal efficiencies up to 81 and 70% were obtained for COD and BOD removal, respectively, in ML-MFC inoculated with anaerobic sludge. Upon changing the inoculum type, a variation of current density and power generation was clearly observed. Within less than four weeks, the system generated a maximum stable current of 55.65 and 67.50 mA/m 2 for ML-MFC inoculated with activated sludge and anaerobic aged sludge, respectively. Effect of inoculum type was evaluated under variable external resistance.
The sorptive behavior of four quaternary ammonium compounds (QACs) -hexadecyl trimethyl ammonium ... more The sorptive behavior of four quaternary ammonium compounds (QACs) -hexadecyl trimethyl ammonium chloride (C 16 TMA), dodecyl trimethyl ammonium chloride (C 12 TMA), hexadecyl benzyl dimethyl ammonium chloride (C 16 BDMA), and dodecyl benzyl dimethyl ammonium chloride (C 12 BDMA) -to municipal primary, waste activated, mesophilic digested, and thermophilic digested sludges was assessed at 22 C. Batch adsorption of all four separately tested QACs to primary sludge reached equilibrium within 4 h. At a nominal, initial QAC concentration of 300 mg/L and a sludge volatile solids concentration of 1 g/L, the extent of adsorption was 13, 88, 67, and 89% for the C 12 TMA, C 16 TMA, C 12 BDMA, and C 16 BDMA, respectively, and correlated positively to the QAC hydrophobicity and negatively to their critical micelle concentration. Equilibrium partitioning data were described by the Freundlich isotherm model. The adsorption capacity of the four sludges was very similar. In binary QAC mixtures, QACs with relatively high adsorption affinity and at relatively high aqueous concentrations decreased the adsorption of QACs with a low adsorption affinity. At pH 7, about 40% of the sludge-C 12 TMA desorbed, whereas less than 5% of the sludge-C 16 BDMA desorbed in 10 days. The effect of pH was negligible on the desorption extent of C 12 TMA at a pH range 4-10 over 10 days, whereas increasing the solution pH to 10 resulted in more than 50% desorption of C 16 BDMA. Given the fact that approximately 50% of the municipal biosolids are land-applied in the US, the data of this study would help in the assessment of the fate of QACs and their potential effect on human and environmental health.
This study aimed to investigate for the first time the utilization of waste compact discs (WCDs) ... more This study aimed to investigate for the first time the utilization of waste compact discs (WCDs) granules in concrete mixtures to replace the fine aggregate by 5%, 10%, 15% and 20 % by weight. The influence of partial replacement of the waste compact discs (WCDs) on the fundamental mechanical and strength properties of the WCDs-modified concrete mixtures were investigated. The properties included workability, bulk density, compressive strength, flexural strength, and split tensile strength. Compared to the control or reference concrete, results revealed that using waste compact discs in concrete mixes mixture improved the workability and the dry density, as well as reducing the compressive strength of concrete containing 10% and 15 % of waste by 15% to 20 %, respectively after 28 days curing. Also, the split tensile strength values of WCDs-modified concrete mixtures were increased by 10% and 12% when the ratio of waste compact discs were 10% and 15 %, respectively after 28 days curi...
Drastic threat to the natural system is caused by the uncontrolled release of synthetic pollutant... more Drastic threat to the natural system is caused by the uncontrolled release of synthetic pollutants, including azo dyes. This study centered on the decolorization and biodegradation of water soluble azo dye reactive blue (RB) in a batch mode sequential anaerobic-aerobic processes. A local sewage treatment plant was the source where activated sludge was collected to be used as non-adapted mixed culture with both free and the alginate immobilized cells for RB biodegradation. Under anaerobic conditions, the free and immobilized mixed cells were proved to completely decolorize 10 mg/ L of RB within 20 and 30 h, respectively. Alginateimmobilized mixed cells, resulted in 88%, 87%, and 87% maximum COD removals with samples containing RB at initial concentration of 10, 20, and 40 mg/L, respectively. UV-vis spectra showed the biological cleavage of the azo bond in the anaerobic phase. Estimation of the phytotoxicity of the degraded metabolites suggested that the non-adapted immobilized mixed bacterial cells successfully detoxified RB azo dye.
The ability of pulverized walnut-shell to remove oil from aqueous solutions has been studied. It ... more The ability of pulverized walnut-shell to remove oil from aqueous solutions has been studied. It involves two-phase process which consists of using walnut-shell as a filtering bed for the accumulation and adsorption of oil onto its surface. Up to 96% oil removal from synthetic wastewater samples was achieved while tests results showed that 75% of oil can be removed from the actual wastewater discharged from Al- Duara refinery in the south of Baghdad.
In recent years and decades, there is a great need for developing new alternative energy sources ... more In recent years and decades, there is a great need for developing new alternative energy sources or renewable sustainable energy. On the other hand, new technology approaches are growing . towards benefits from the valuable nutrients in wastewater which are unrecoverable by traditional wastewater treatment processes. In the current study, a novel integrated system of microbial fuel cell and anoxic bioreactor (MFC-ANB) was designed and constructed to investigate its potential for slaughterhouses wastewater treatment, nitrogen recovery, and power generation. The system consisted of a double-chamber tubular type MFC with biocathode inoculated with freshly collected activated sludge. The MFC-ANB system was continuously fed with real-field slaughterhouse wastewater, with initial concentrations of COD and ammonium were 990 mg/L and 200 mg-N/L, respectively. The MFC-ANB system was operated for a total period of 43 days. Maximum removal efficiencies of COD, ammonium, nitrate, nitrogen reco...
This study aimed to investigate the effect of total suspended solids (TSS) on the performance of ... more This study aimed to investigate the effect of total suspended solids (TSS) on the performance of a continuously operated dual-chamber microbial fuel cell (MFC) proceeded by primary clarifier to treat actual potato chips processing wastewater. The system was also tested in the absence of the primary clarifier and the results demonstrated a significant effect of TSS on the polarization curve of the MFC which was obtained by operating the graphite anodic electrode against Ag/AgCl reference electrode. The maximum observed power and current densities were decreased form 102.42 mW/m2 and 447.26 mA/m2 to 80.16 mW/m2 and 299.10 mA/m2, respectively due to the adverse effect of TSS. Also, the internal resistance increased from 40 to 70Ω.
In this study, a dual-chamber microbial fuel cell (MFC) fed with actual potato chips' processing ... more In this study, a dual-chamber microbial fuel cell (MFC) fed with actual potato chips' processing wastewater (PCPW) was tested as a biosensor. The performance of MFC-based biosensor was evaluated in terms of the current measurement range, toxicity detection and sensitivity, and the operational stability. The results revealed that the MFC can simply be converted to an online biosensor unit to detect the harmful effect of suspended solids and acidic content in the actual PCPW on the anodic attached biofilm and the values of the generated current as well. A notable decrease in the current values was observed indicating the adverse effects of the harmful matters in the PCPW fed to the biosensor unit. The results proposed a competition between the harmful components and the favorable substrate in binding to the redox complex. An excellent fitting was obtained between the experimental and predicted results by I K m model with determination coefficient (R 2) and mean-squareerror values of 0.927 and 0.363, respectively. Additionally, a new approach was developed based on direct measurement of actual field data to replace the conventional statistical methods.
This study aimed to investigate the feasibility of treatment actual potato chips processing waste... more This study aimed to investigate the feasibility of treatment actual potato chips processing wastewater in a continuously operated dual chambers microbial fuel cell (MFC) inoculated with anaerobic sludge. The results demonstrated significant removal of COD and suspended solids of more than 99% associated with relatively high generation of current and power densities of 612.5 mW/m3 and 1750 mA/m3, respectively at 100 Ω external resistance.
This study aimed to investigate the performance of microbial fuel cell (MFC) for simultaneous bio... more This study aimed to investigate the performance of microbial fuel cell (MFC) for simultaneous bioremediation of slaughterhouse wastewater and sustainable power generation. For the first time, an integrated system of tubular type microbial fuel cell (MFC) was used in this study. The MFC consisted of three concentric Plexiglas tubes; the inner tube was the anaerobic anodic compartment, the mid tube was the aerobic biocathodic chamber, and the outer tube act as an aerobic bioreactor for extended nitrification process. The MFC system was connected to a complementary external anaerobic bioreactor for denitrification process. The microbial fuel cell was inoculated with freshly collected activated sludge and was continuously fueled with simulated slaughterhouse wastewater. Results revealed that the removal efficiency of the chemical oxygen demand (COD) was up to 99%, and the power generation was 165 mW/m 2 . Also, results demonstrated that maximum removal of NO3 via the denitrification pro...
In this study, a novel application of lab-scale dual chambered air-cathode microbial fuel cell (M... more In this study, a novel application of lab-scale dual chambered air-cathode microbial fuel cell (MFC) has been developed for simultaneous bio-treatment of real pharmaceutical wastewater and renewable electricity generation. The microbial fuel cell (MFC) was provided with zeolite-packed anodic compartment and a cation exchange membrane (CEM) to separate the anode and cathode. The performance of the proposed MFC was evaluated in terms of COD removal and power generation based on the activity of the bacterial consortium in the biofilm mobilized on zeolite bearer. The MFC was fueled with real pharmaceutical wastewater having an initial COD concentration equal to 800 mg/L and inoculated with anaerobic aged sludge. Results demonstrated that the COD removal efficiency, power density and current density were 66%, 2.4 mW/m2 and 10 mA/m2, respectively.
A new bio-electrochemical system was proposed for simultaneous removal of organic matters and sal... more A new bio-electrochemical system was proposed for simultaneous removal of organic matters and salinity from actual domestic wastewater and synthetically prepared saline water, respectively. The performance of a three-chambered microbial osmotic fuel cell (MOFC) provided with forward osmosis (FO) membrane and cation exchange membrane (CEM) was evaluated with respect to the chemical oxygen demand (COD) removal from wastewater, electricity generation, and desalination of saline water. The MOFC wasinoculated with activated sludge and fueled with actual domestic wastewater. Results revealed that maximum removal efficiency of COD from wastewater, TDS removal efficiency from saline water, power density, and current density were 96%, 90%, 30.02 mW/m2, and 107.20 mA/m2, respectively.
Advances in Science and Technology Research Journal
This study investigated the potential of biogas recovery from refinery oily sludge (ROS) inoculat... more This study investigated the potential of biogas recovery from refinery oily sludge (ROS) inoculated with animals' manure by co-digestion of in lab-scale biodigesters at mesophilic conditions. Cow dung (CD), cattle manure (CM), and poultry manure (PM) were utilized as co-substrates. The biogas production from the co-digestion process exceeds its production from uninoculated ROS by approximately 67.5, 22.13 and 21.6% for PM, CM, and CD, respectively. Kinetics of the co-digestion process was well described by the modified Gompertz model. The predicted and experimental values of biogas production were well fitted with R 2 > 0.96, suggesting favorable conditions of the digestion process. New approach for recycling the residual digestate to replace freshwater in concrete mixes was carried out. Results of examining the mechanical properties of the residual digestate-modified concrete mixes demonstrated a potential sustainable approach for the disposal of residual digestate in concrete mixes.
Cell immobilization has been proven to offer noticeable benefits over conventional biological sys... more Cell immobilization has been proven to offer noticeable benefits over conventional biological systems using free cells, particularly for recalcitrant compounds. In this study, mixed bacterial cells were alternatively immobilized in sodium alginate (SA) and in sodium alginate-polyvinyl alcohol (SA-PVA) for biodegradation of sodium dodecyl sulfate (SDS). Synthetically prepared SDS-bearing aqueous solution (SWW), as well as actual automobile service station wastewater (AWW) and laundry wastewater (LWW) were used. The results revealed that high removal efficiencies were achieved after 48 h for both types of beads. When SDS concentration in SWW increased from 10 to 1000 mg L-1 , SDS degradation using both types of beads were decreased from 99.71 % to 85.12 % using SA beads, and from 99.63 % to 83.29 % using SA-PVA beads. The removal efficiency of SDS in the actual (AWW) were 94.91 % and 93.82 % using SA beads and SA-PVA beads, respectively. While, for SDS-bearing laundry (LWW), the removal efficiencies were 94.39 % and 92.04 % using SA beads and SA-PVA beads, respectively. No decline in the biodegradation capacity of immobilized consortium was noted over its recycling and reuse. Both hydrogel matrices lasted for up to five cycles in the actual wastewaters. These promising results confirmed the validity of using immobilized mixed cells as an efficient and cost-effective approach for SDS biodegradation in real industrial wastewaters.
Biodegradation is an environmentally friendly and cost-effective alternative that proved to be ef... more Biodegradation is an environmentally friendly and cost-effective alternative that proved to be efficient for the removal of toxic phenol compounds from aqueous solutions. However, it has been reported that phenol is inhibitory to bacterial growth at concentrations above 0.05 g/L. This study was undertaken to study the degradation of phenol at initial concentrations of 20 mg/L by Bacillus cells individually immobilized in two different matrices including polyvinyl alcohol-sodium alginate (PVA-SA) and polyvinyl alcohol-guar gum (PVA-GG). Results of batch experiments demonstrated that complete removal of phenol was obtained using immobilized cells in the first cycle after 270 and 300 min using cells immobilized in PVA-SA and PVA-GG. Additional cycles were conducted to evaluate the validity of recycling the beads of immobilized cells for phenol biodegradation. Results revealed that the phenol percentage removals were 96, 90, 83, and 75% for the second, third, fourth, and fifth cycles, r...
Metals and plastics waste materials create serious environmental problems, mainly owing to the in... more Metals and plastics waste materials create serious environmental problems, mainly owing to the inconsistency of the wastes streams. The purpose of this paper is to evaluate the possibility of using mixed iron filings and granulated plastic waste materials simultaneously to partially substitute the fine aggregate in concrete composites. Type I Portland cement was mixed with the aggregates to produce the concrete composites. Three weight fractions (30, 40, and 50%) of iron filings waste aggregate were used with 5% of granulated plastic waste. The slump, compressive and flexural strengths as well as the fresh and hard density of the concrete mixtures were determined. The results of the mechanical properties were analyzed in comparison to the control specimens. The main findings of this investigation revealed that the mixture of iron filings and plastic waste materials could be used successfully as partial substitutes of sand in concrete composites. Increasing the granulated plastic was...
International Journal of Energy, Environment and Economics
Anaerobic digestion is a technology widely used for treatment of organic waste to enhance biogas ... more Anaerobic digestion is a technology widely used for treatment of organic waste to enhance biogas recovery. In this study, recycling of date palm wastes (DPWs) was examined as a source for biogas production. The effects of inoculum addition, pretreatment of substrate, and temperature on the biogas production were investigated in batch mode digesters. Results revealed that the effect of inoculum addition was more significant than alkaline pretreatment of raw waste materials. The biogas recovery from inoculated DPWs exceeds its production from DPWs without inoculation by approximately 140% at mesophilic conditions. Whereby, the increase of biogas recovery from pretreated DPWs was 52% higher than its production from untreated DPWs at mesophilic conditions. The thermophilic conditions improved the biogas yield by approximately 23%. The kinetic of bio-digestion process was well described by modified Gompertz model and the experimental and predicted values of biogas production were fitted well with correlation coefficient values > 0.96 suggesting favorable conditions of the process.
Industrial activities in Iraq are associated with significant amounts of non-biodegradable solid ... more Industrial activities in Iraq are associated with significant amounts of non-biodegradable solid waste, waste plastic being among the most prominent. This study involved 86 experiments and 254 tests to determine the efficiency of reusing waste plastic in the production of concrete. Thirty kilograms of waste plastic of fabriform shapes was used as a partial replacement for sand by 0%, 10%, 15%, and 20% with 800 kg of concrete mixtures. All of the concrete mixtures were tested at room temperature. These tests include performing slump, fresh density, dry density, compressive strength, flexural strength, and toughness indices. Seventy cubes were molded for compressive strength and dry density tests, and 54 prisms were cast for flexural strength and toughness indices tests. Curing ages of 3, 7, 14, and 28 days for the concrete mixtures were applied in this work. The results proved the arrest of the propagation of micro cracks by introducing waste plastic of fabriform shapes to concrete mixtures. This study insures that reusing waste plastic as a sand-substitution aggregate in concrete gives a good approach to reduce the cost of materials and solve some of the solid waste problems posed by plastics.
In this study, electricity generation integrated with organic substrate biodegradation was invest... more In this study, electricity generation integrated with organic substrate biodegradation was investigated in a continuous mediator-less microbial fuel cell with graphite electrodes and a selective type of membrane separating the anodic and cathodic compartments of MFC from each other. The performance of MFC was evaluated to treat actual domestic wastewater using aged anaerobic sludge. Results revealed that COD and BOD removal efficiencies were up to 88% and 75%, respectively. At an external resistance value of 100 Ω, a maximum power and current values of 318 mV and 3.11 mA, respectively were obtained.
Microbial fuel cells (MFCs) have the potential to simultaneously treat wastewater for reuse and t... more Microbial fuel cells (MFCs) have the potential to simultaneously treat wastewater for reuse and to generate electricity. This study mainly considers the performance of an upflow dual-chambered MFC continuously fueled with actual domestic wastewater and alternatively biocatalyzed with aerobic activated sludge and strain ofBacillus Subtilis. The behavior of MFCs during initial biofilm growth and characterization of anodic biofilm were studied. After 45 days of continuous operation, the biofilms on the anodic electrode were well developed. The performance of MFCs was mainly evaluated in terms of COD reductions and electrical power output. Results revealed that the COD removal efficiency was 84% and 90% and the stabilized power outputs were clearly observed achieving a maximum value of 120 and 270 mW/m2obtained for MFCs inoculated with mixed cultures andBacillus Subtilisstrain, respectively.
The performance of a membrane-less microbial fuel cell (ML-MFC) was evaluated to treat actual dom... more The performance of a membrane-less microbial fuel cell (ML-MFC) was evaluated to treat actual domestic wastewater. A novel application of inexpensive acrylic beads was examined to separate the anodic and cathodic compartments. The ML-MFC was alternatively inoculated with activated sludge and anaerobic aged sludge. Results revealed that the removal efficiencies of COD and BOD from actual wastewater were 79 and 60%, respectively, using the activated sludge as inoculum. Higher removal efficiencies up to 81 and 70% were obtained for COD and BOD removal, respectively, in ML-MFC inoculated with anaerobic sludge. Upon changing the inoculum type, a variation of current density and power generation was clearly observed. Within less than four weeks, the system generated a maximum stable current of 55.65 and 67.50 mA/m 2 for ML-MFC inoculated with activated sludge and anaerobic aged sludge, respectively. Effect of inoculum type was evaluated under variable external resistance.
The sorptive behavior of four quaternary ammonium compounds (QACs) -hexadecyl trimethyl ammonium ... more The sorptive behavior of four quaternary ammonium compounds (QACs) -hexadecyl trimethyl ammonium chloride (C 16 TMA), dodecyl trimethyl ammonium chloride (C 12 TMA), hexadecyl benzyl dimethyl ammonium chloride (C 16 BDMA), and dodecyl benzyl dimethyl ammonium chloride (C 12 BDMA) -to municipal primary, waste activated, mesophilic digested, and thermophilic digested sludges was assessed at 22 C. Batch adsorption of all four separately tested QACs to primary sludge reached equilibrium within 4 h. At a nominal, initial QAC concentration of 300 mg/L and a sludge volatile solids concentration of 1 g/L, the extent of adsorption was 13, 88, 67, and 89% for the C 12 TMA, C 16 TMA, C 12 BDMA, and C 16 BDMA, respectively, and correlated positively to the QAC hydrophobicity and negatively to their critical micelle concentration. Equilibrium partitioning data were described by the Freundlich isotherm model. The adsorption capacity of the four sludges was very similar. In binary QAC mixtures, QACs with relatively high adsorption affinity and at relatively high aqueous concentrations decreased the adsorption of QACs with a low adsorption affinity. At pH 7, about 40% of the sludge-C 12 TMA desorbed, whereas less than 5% of the sludge-C 16 BDMA desorbed in 10 days. The effect of pH was negligible on the desorption extent of C 12 TMA at a pH range 4-10 over 10 days, whereas increasing the solution pH to 10 resulted in more than 50% desorption of C 16 BDMA. Given the fact that approximately 50% of the municipal biosolids are land-applied in the US, the data of this study would help in the assessment of the fate of QACs and their potential effect on human and environmental health.
This study aimed to investigate for the first time the utilization of waste compact discs (WCDs) ... more This study aimed to investigate for the first time the utilization of waste compact discs (WCDs) granules in concrete mixtures to replace the fine aggregate by 5%, 10%, 15% and 20 % by weight. The influence of partial replacement of the waste compact discs (WCDs) on the fundamental mechanical and strength properties of the WCDs-modified concrete mixtures were investigated. The properties included workability, bulk density, compressive strength, flexural strength, and split tensile strength. Compared to the control or reference concrete, results revealed that using waste compact discs in concrete mixes mixture improved the workability and the dry density, as well as reducing the compressive strength of concrete containing 10% and 15 % of waste by 15% to 20 %, respectively after 28 days curing. Also, the split tensile strength values of WCDs-modified concrete mixtures were increased by 10% and 12% when the ratio of waste compact discs were 10% and 15 %, respectively after 28 days curi...
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Papers by Zainab Ismail