In this study, natural coagulant obtained from walnut seeds was used in water treatment for the r... more In this study, natural coagulant obtained from walnut seeds was used in water treatment for the removal of turbidity as a coagulant and as a coagulant aid with alum. The study was conducted by using a jar test under various operational parameters. The tests were carried out with initial turbidity of 10–200 NTU, pH of 3–11, and natural coagulant dose of 1–5 ml/L. The characterization of walnut natural coagulant was carried out using SEM, FTIR, EDX, and zeta potential analyzer. The coagulation activity and turbidity removal efficiency were evaluated for each run. The optimum dose of the walnut seed extract may be found to 3 ml/L. The highest turbidity removal efficiency was achieved at pH above 7. Walnut seed extract used as coagulant and with alum was able to enhance coagulation process performance and decrease the alum dose required for the coagulation process performance and decrease the alum dose required for the coagulation process. Walnut seed extract has a negligible impact on ...
The effect of planting covers, shading and solar radiation on the bioaerosol have been estimated ... more The effect of planting covers, shading and solar radiation on the bioaerosol have been estimated for several wastewater treatment plants "WWTP", working by activated sludge processes "ASP". For each plant, the microorganisms has been estimated in air as colony forming units per cubic meter (CFU/M 3 ) under different conditions of planting cover density, shading condition and solar radiation. In addition the secondary parameters such as boundary conditions, wind direction, temperature and measurement times have been considered. It was found that, there is a direct relationship between bioaerosol pollution in the air and both of planting density and shading ratio. Conversely, there is an inversely relationship between solar radiation and bioaerosol pollution. Despite the air quality improvements that take place by plants. They increase microorganisms account in the air. Also presence of shades in the WWTP and around it increase microorganisms account in air. Bioaerosol pollution has multiplied several times under plants from 1366 CFU/M 3 to 14597 CFU/M 3 , also by shade from 4976 CFU/M 3 to 19704 CFU/M 3 , but solar radiation decreased the pollution value from 13933 CFU/M 3 to 796 CFU/M 3 .
The steady state completely mixed biofilm-activated sludge reactor (hybrid reactor) is described ... more The steady state completely mixed biofilm-activated sludge reactor (hybrid reactor) is described using an approximated model. A mathematical model has been derived based on the fundamental concepts and Monod expressions. For approximated model instead of the biofilm variables an empirical function is described. Hence the complexity for evaluation of the biofilm parameters has been removed. Further the approximation has reduced the number of required variables, simplified the calculation, and thus reduced the solution steps. At the same time, the solution still considers the basic concepts of the suspended and attached growth simultaneously and the influence of substrate transport limitations of biofilm. The empirical function could be evaluated based on experimental data and curve fitting for a specific type of substrate. The model is arranged in explicit form, which can be used easily by engineers and designers. With regard to the whole range of available models for other aerobic s...
The optimum and critical conditions for the nitrification efficiency were developed experimentall... more The optimum and critical conditions for the nitrification efficiency were developed experimentally in completely mixed biofilm-activated sludge reactor (hybrid reactor). A hybrid reactor was exposed to washout conditions for a suspended biomass with presence of fixed biofilm. As a result five different stages corresponding to five ratios of the active biofilm to the suspended biomass were obtained. During all these stages the nitrification efficiency as well as the carbonaceous removal were observed. It was found that, in stage one at low effluent substrate COD concentration (S), the nitrification efficiency attains its optimum value despite the negligible role of the biofilm for COD removal. After washout of the suspended biomass when the system converts to pure attached reactor (stage five) the nitrification efficiency is high but lower than stage one. Further, at some value of S when the biofilm and the suspended biomass have approximating equal roles in the treatment (stage thre...
A new configuration of the one stage direct filtration process has been investigated by Prof. Fad... more A new configuration of the one stage direct filtration process has been investigated by Prof. Fadel (correspondent author) and his team in Mansoura University, Egypt. In this configuration, deep media with fine gravel particles (size 2-4 mm) has been used under low filtration rate (5-8 m 3 /m 2 /hr). For this system a simplified empirical model is proposed to describe the one stage of direct filtration process under steady-state conditions. The model is obtained based on curve fitting of true field data, which is obtained from several plants employing direct filtration process. The model considers all the essential concepts that describe the two processes of flocculation and filtration in one tank and the competition between them for limiting depth. Further, the model has considered all the major factors, which affect on the filtration process such as filter depth, filtration rate, run length, run time, size of media, and alum dose. The present model has an explicit solution, which ...
Biogas production rate from sewage water has been increased more than 80% by adding digestive enz... more Biogas production rate from sewage water has been increased more than 80% by adding digestive enzymes to simulated and natural sewage water under different operational conditions. These enzymes have included pepsin, Ox bile extract, single and mixed with concentration of (0.25, 0.5, 1, 2, 4) mg/l and (20, 30, 40, 50, 60) mg/l as respectively. So the impact of addition of mixtures of enzymes (Lipase (L), Amylase (AM) and Protease (P)) at concentration shown in research, under temperature 20 ̊and 37.5 ̊C.pH 6.5-7.2, the duration of fermentation is 12 days. The amount of salinity is ranged between (1004 – 1474) micromhos/cm. The results showed that the addition of any digestive enzyme to sewage water increases biogas production at least10:20 % in short retention time. However, to get maximum biogas production, it is necessary to add at least two or three digestive enzymes simultaneously to sewage water. Up to two different digestive enzymes can increase biogas production from sewage wa...
Contamination of groundwater with heavy metals may have harmful effects on the lives of people wh... more Contamination of groundwater with heavy metals may have harmful effects on the lives of people who depend on groundwater for drinking and other life purposes. Several techniques were used to remove the pollutants from the water, such as chemical precipitation, ion exchange, coagulation, electrochemical treatment, and adsorption. The last method is preferred due to its simplicity, easy recovery, and high effectiveness. Chemical analysis of the natural peat soil and the Fe (II) aqueous solution were performed. The characteristics of the soil were identified using X-ray diffraction (XRD), scanning electron microscope (SEM), and X-ray fluorescence (XRF). Furthermore, experimental work was carried out to investigate the effect of operational parameters on the removal efficiency% and adsorption capacity of natural peat to remove pollutants from aqueous solution. The operating parameters were the contact time, Fe initial concentration, adsorbent thickness, and adsorbent dose. The results ...
A conventional sequencing batch reactor (SBR) was upgraded using fixed biofilm
carriers with a sp... more A conventional sequencing batch reactor (SBR) was upgraded using fixed biofilm carriers with a specific surface area around 18 m2 m−3. The upgraded SBR was investigated to remove phenol from high strength wastewater operated under various operational conditions. The operational conditions used were variable volume exchange ratio (VER) up to 75%, hydraulic retention time (HRT) from (10.7–21.3 hr), aeration time (from 2 to 8 hr), and initial phenol concentration up to 600 mg L−1. It was found that the upgraded SBR increased the removal efficiencies of biological oxygen demand (BOD5), chemical oxygen demand (COD), and total suspended solids (TSS) by about 10% using high strength wastewater without phenol compared to SBR. Furthermore, the removal rate of phenol for the upgraded SBR was higher than conventional SBR by about 18% at 600 mg L− of initial phenol concentration under the same operational conditions. Compared to the conventional SBR, the upgraded version reduced the aeration step by 25% and achieved higher removal efficiency of phenol. Moreover, it reduced the excess sludge by about 23% and enhanced its properties by lowering the sludge volume index (SVI) by about 33%.
Bulletin of the Faculty of Engineering. Mansoura University
A raw wastewater has been treated in wastewater treatment plant of Met Abo El-Kom city using atta... more A raw wastewater has been treated in wastewater treatment plant of Met Abo El-Kom city using attached growth systems. The treatment was accomplished using an Aerated Fixed Film Reactor (AFFR) with plastic plates or plastic plates with plastic mesh. The first reactor consisted of a number of biofilm carriers from fiber glass plates. Another modified (AFFAR) has been used by modifying the first one by attaching plastic mesh to enhance biofilm area. The system was run in the field for more than six months. Practically, the system consistsed of four stages as with bafflers at hydraulic loading rate (HLR) of 0.1 and 0.2 m 3 /m 2 /d. The results showed under HLR= 0.1 m 3 /m 2 /d for the first reactor has achieved a removal efficiency of 89%, 95%, 90% and 93% for COD, BOD 5 , NH 3 and TSS respectively. However, the second modified reactor achieved high removal efficiency more than the first one because of the large biofilm area. The second reactor has achieved a removal efficiency of 94%, 98%, 95% and 97 for COD, BOD 5 , NH 3 and TSS respectively. The influent BOD 5 has been decreased from of 600 to 7 mg/l with removal percentage 98%. Removal of COD and SS was almost similar to that of BOD. The initial COD and SS of 800 mg/l and 510 mg/l come down to 71 mg/l and 20 mg/l respectively. In addition, the present study illustrated that use of biofilm carrier (plastic plates) improve the growth of biomass above surface area of plates and have a relative large surface area in small volume. Results also indicated that better removal efficiency can be obtained in case of low hydraulic loading rate of 0.1m 3 /m 2 /d especially for BOD 5 and COD. While in case of modified AFFR the effluent improved BOD 5 , COD, NH 3 and TSS removal.
Bulletin of the Faculty of Engineering. Mansoura University
Filtration is the main process in water treatment plant. In this process the water passing throug... more Filtration is the main process in water treatment plant. In this process the water passing through some porous media (sand) to remove the suspended solids and impurities. In the beginning of filtration process, the head loss is small and it can be easily calculated by different empirical equations, but as the filter bed gets clogged, the head loss increases. The pilot plant was installed in sanitary engineering laboratory, Mansoura University. The operating conditions have five explanatory parameters. These parameters are filter depth, filtration rate, run time, influent turbidity, and alum dose. The filter depth was ranged from 80 to 140 cm and alum dose were ranged from 20 to 50 mg/lit. The rate of filtration was used in the range from 4 to 8 m/hr and the initial turbidities varied from 10 to 50 NTU. A mathematical model was obtained for head loss through deep bed sand filter with various operating conditions (filter depth, filtration rate, alum dose, run time, and initial turbidity).The proposed model yield highly accurate results with correlation coefficient (R 2) of 0.88. The proposed model showed that the most significant parameters on predicted head loss are the run time and filtration rate. Also, the simple proposed model can be easily and effectively used as a decision supporting tool for prediction of filtration run length.
The performance of a sludge blanket clarifier was evaluated and compared to conventional settlers... more The performance of a sludge blanket clarifier was evaluated and compared to conventional settlers under high levels of turbidity and algae in the field and experimentally. Field data of sludge blanket and conventional clarifier operation were observed simultaneously for the treatment of highly turbid water. In addition, a comparison was carried out on turbidity removal efficiency, algae removal, and sludge accumulation pattern. Finally, these systems were simulated in the laboratory and operated to treat turbid water with high levels of turbidity and algae up to 80 NTU and 109cells/l respectively. Field data confirmed that the sludge blanket clarifier equipped with upper sludge cones has a high removal efficiency of turbidity and algae, ease of use and has insignificant sludge accumulation compared to the conventional settler. Further, laboratory experiments have confirmed that sludge blanket clarifier is also very effective for the treatment of high algae concentrations up to 109ce...
Algae-blanket phenomenon has been observed inside a large-scale flat-bottom clarifier for water t... more Algae-blanket phenomenon has been observed inside a large-scale flat-bottom clarifier for water treatment. This phenomenon occurred after running the reactor under high concentration of algae (10 9 cells/l) for a long time especially in hot climate regions. Under that high algae concentration, pre-chlorination doses up to 4.0 mg/l was not sufficient to prevent algae accumulation inside the sludge blanket layer. So, a gradual accumulation of algae (such as Chlorella, Melosira, and Pediastrum) occurred inside the sludge blanket, converting the whole blanket, to algae blanket after a specific period. So, this phenomenon depends on the algae concentration of the raw water, pre-chlorination dose, and the environmental conditions. As soon as the algal blanket is formed, the clarifier's performance is affected negatively. Algae blanket depletes all chlorine in the upper layer above it resulting in an accumulation of green weeds in that layer, as well as decreases the removal efficiency of the clarifier drastically. Finally, total failure of the clarifiers occurs after a few days associated with filter clogging. However, laboratory experiments confirmed this phenomenon and recommended that daily shock dose using chlorine with a concentration of 6.0 mg/l for one hour can prevent algae accumulation inside the sludge blanket layer.
A complete graphical solution is obtained for the completely mixed biofilm-activated sludge react... more A complete graphical solution is obtained for the completely mixed biofilm-activated sludge reactor (hybrid reactor). The solution consists of a series of curves deduced from the principal equations of the hybrid system after converting them in dimensionless form. The curves estimate the basic parameters of the hybrid system such as suspended biomass concentration, sludge residence time, wasted mass of sludge, and food to biomass ratio. All of these parameters can be expressed as functions of hydraulic retention time, influent substrate concentration, substrate concentration in the bulk, stagnant liquid layer thickness, and the minimum substrate concentration which can maintain the biofilm growth in addition to the basic kinetics of the activated sludge process in which all these variables are expressed in a dimensionless form. Compared to other solutions of such system these curves are simple, easy to use, and provide an accurate tool for analyzing such system based on fundamental principles. Further, these curves may be used as a quick tool to get the effect of variables change on the other parameters and the whole system.
Large quantities of sludge are produced during water treatment processes. Recently, sludge has be... more Large quantities of sludge are produced during water treatment processes. Recently, sludge has been treated as waste and disposed of in landfills, which increases the environmental burdens and the operational cost. Therefore, sludge reuse has become a significant environmental issue. In this study, adsorption of copper ions (Cu2+) onto calcined sludge was investigated under various operational conditions (with varying temperature, Cu2+ initial concentration, pH, and sludge dosage). The prepared sludge material was characterized with transmission electron microscopy (TEM), X-ray diffraction (XRD), dynamic light scattering (DLS), and Brunauer-Emmett-Teller (BET) surface area. The sorption capacity of sludge was directly proportional to the initial Cu2+ concentration and inversely proportional to the sludge dosage. The optimum operational pH and solution temperature were 6.6 and 80°C, respectively. The experimental results followed a Langmuir isotherm and pseudo-first-order adsorption kinetics. Thermodynamic parameters such as activation energy, change in free energy, enthalpy, and entropy were calculated. Thermodynamic analyses indicated that the sorption of copper ions onto the calcined sludge was driven by a physical adsorption process. The prepared sludge was proven to be an excellent adsorbent material for the removal of Cu2+ from an aqueous solution under optimum conditions.
There are some sources of pollution of the groundwater such as the industrial, agriculture, domes... more There are some sources of pollution of the groundwater such as the industrial, agriculture, domestic activities and the oxidation ponds that are considered collection points for waste disposal plants. The motivations to do this work were: (1) investigating the concentrations of pollutants in the oxidation ponds and well surrounding the 10th Ramadan city and (2) predicting the groundwater flow and the pollutant transport to the groundwater from the pollution source using a numerical simulation (MODFLOW-2000 with MT3D code). The samples of groundwater were collected from the wells that spread around the studied area as well as many samples were collected from the oxidation ponds to investigate the concentrations of pollutants in these samples and predict the pollutant transport to the groundwater over 30 years. The results illustrated that the ion concentration of most samples from the oxidation ponds resources contained Al 3+ , Fe 2+ , Sr 2+ , Ni 2+ , and Cr 2+ which were exceeding the acceptable limit of WHO (International standards for drinking water, WHO, Geneva, 1996) standards. The results also demonstrated that most of the analyzed groundwater samples are polluted with strontium (Sr 2+), aluminum (Al 3+), and iron (Fe 2+). The simulation predicted that the pollutants movements toward the northeast of the study zone over a long-term period (30 years).
The present study was carried out to simplify existing biofilm one-dimensional models, which cons... more The present study was carried out to simplify existing biofilm one-dimensional models, which consider a single substrate as the limiting factor. Models of Suidan and Wang (1985) and Sáez and Rittmann (1988, 1992) were selected for the present study. Thus, modified expressions were developed for the first one, while the exact solution of the second one could be obtained. The modified expressions and the exact solution are short, simple, easy to use, and give reliable results in comparison to the original models. In addition, the proposed expressions and solution can be used instead of the graphical solutions, which are commonly used to solve the original models. Applicability of the developed expressions has been demonstrated through an illustrative example. The proposed expressions and the present study may be useful to simplify the description of biofilm in many systems such as completely mixed or fluidized-bed reactor for treatment of water or wastewater as well as the biofilm-activated sludge reactors. Moreover, the exact solution from this study can be used to establish the biofilm kinetics instead of using the curve-matching technique.
In this study, natural coagulant obtained from walnut seeds was used in water treatment for the r... more In this study, natural coagulant obtained from walnut seeds was used in water treatment for the removal of turbidity as a coagulant and as a coagulant aid with alum. The study was conducted by using a jar test under various operational parameters. The tests were carried out with initial turbidity of 10–200 NTU, pH of 3–11, and natural coagulant dose of 1–5 ml/L. The characterization of walnut natural coagulant was carried out using SEM, FTIR, EDX, and zeta potential analyzer. The coagulation activity and turbidity removal efficiency were evaluated for each run. The optimum dose of the walnut seed extract may be found to 3 ml/L. The highest turbidity removal efficiency was achieved at pH above 7. Walnut seed extract used as coagulant and with alum was able to enhance coagulation process performance and decrease the alum dose required for the coagulation process performance and decrease the alum dose required for the coagulation process. Walnut seed extract has a negligible impact on ...
The effect of planting covers, shading and solar radiation on the bioaerosol have been estimated ... more The effect of planting covers, shading and solar radiation on the bioaerosol have been estimated for several wastewater treatment plants "WWTP", working by activated sludge processes "ASP". For each plant, the microorganisms has been estimated in air as colony forming units per cubic meter (CFU/M 3 ) under different conditions of planting cover density, shading condition and solar radiation. In addition the secondary parameters such as boundary conditions, wind direction, temperature and measurement times have been considered. It was found that, there is a direct relationship between bioaerosol pollution in the air and both of planting density and shading ratio. Conversely, there is an inversely relationship between solar radiation and bioaerosol pollution. Despite the air quality improvements that take place by plants. They increase microorganisms account in the air. Also presence of shades in the WWTP and around it increase microorganisms account in air. Bioaerosol pollution has multiplied several times under plants from 1366 CFU/M 3 to 14597 CFU/M 3 , also by shade from 4976 CFU/M 3 to 19704 CFU/M 3 , but solar radiation decreased the pollution value from 13933 CFU/M 3 to 796 CFU/M 3 .
The steady state completely mixed biofilm-activated sludge reactor (hybrid reactor) is described ... more The steady state completely mixed biofilm-activated sludge reactor (hybrid reactor) is described using an approximated model. A mathematical model has been derived based on the fundamental concepts and Monod expressions. For approximated model instead of the biofilm variables an empirical function is described. Hence the complexity for evaluation of the biofilm parameters has been removed. Further the approximation has reduced the number of required variables, simplified the calculation, and thus reduced the solution steps. At the same time, the solution still considers the basic concepts of the suspended and attached growth simultaneously and the influence of substrate transport limitations of biofilm. The empirical function could be evaluated based on experimental data and curve fitting for a specific type of substrate. The model is arranged in explicit form, which can be used easily by engineers and designers. With regard to the whole range of available models for other aerobic s...
The optimum and critical conditions for the nitrification efficiency were developed experimentall... more The optimum and critical conditions for the nitrification efficiency were developed experimentally in completely mixed biofilm-activated sludge reactor (hybrid reactor). A hybrid reactor was exposed to washout conditions for a suspended biomass with presence of fixed biofilm. As a result five different stages corresponding to five ratios of the active biofilm to the suspended biomass were obtained. During all these stages the nitrification efficiency as well as the carbonaceous removal were observed. It was found that, in stage one at low effluent substrate COD concentration (S), the nitrification efficiency attains its optimum value despite the negligible role of the biofilm for COD removal. After washout of the suspended biomass when the system converts to pure attached reactor (stage five) the nitrification efficiency is high but lower than stage one. Further, at some value of S when the biofilm and the suspended biomass have approximating equal roles in the treatment (stage thre...
A new configuration of the one stage direct filtration process has been investigated by Prof. Fad... more A new configuration of the one stage direct filtration process has been investigated by Prof. Fadel (correspondent author) and his team in Mansoura University, Egypt. In this configuration, deep media with fine gravel particles (size 2-4 mm) has been used under low filtration rate (5-8 m 3 /m 2 /hr). For this system a simplified empirical model is proposed to describe the one stage of direct filtration process under steady-state conditions. The model is obtained based on curve fitting of true field data, which is obtained from several plants employing direct filtration process. The model considers all the essential concepts that describe the two processes of flocculation and filtration in one tank and the competition between them for limiting depth. Further, the model has considered all the major factors, which affect on the filtration process such as filter depth, filtration rate, run length, run time, size of media, and alum dose. The present model has an explicit solution, which ...
Biogas production rate from sewage water has been increased more than 80% by adding digestive enz... more Biogas production rate from sewage water has been increased more than 80% by adding digestive enzymes to simulated and natural sewage water under different operational conditions. These enzymes have included pepsin, Ox bile extract, single and mixed with concentration of (0.25, 0.5, 1, 2, 4) mg/l and (20, 30, 40, 50, 60) mg/l as respectively. So the impact of addition of mixtures of enzymes (Lipase (L), Amylase (AM) and Protease (P)) at concentration shown in research, under temperature 20 ̊and 37.5 ̊C.pH 6.5-7.2, the duration of fermentation is 12 days. The amount of salinity is ranged between (1004 – 1474) micromhos/cm. The results showed that the addition of any digestive enzyme to sewage water increases biogas production at least10:20 % in short retention time. However, to get maximum biogas production, it is necessary to add at least two or three digestive enzymes simultaneously to sewage water. Up to two different digestive enzymes can increase biogas production from sewage wa...
Contamination of groundwater with heavy metals may have harmful effects on the lives of people wh... more Contamination of groundwater with heavy metals may have harmful effects on the lives of people who depend on groundwater for drinking and other life purposes. Several techniques were used to remove the pollutants from the water, such as chemical precipitation, ion exchange, coagulation, electrochemical treatment, and adsorption. The last method is preferred due to its simplicity, easy recovery, and high effectiveness. Chemical analysis of the natural peat soil and the Fe (II) aqueous solution were performed. The characteristics of the soil were identified using X-ray diffraction (XRD), scanning electron microscope (SEM), and X-ray fluorescence (XRF). Furthermore, experimental work was carried out to investigate the effect of operational parameters on the removal efficiency% and adsorption capacity of natural peat to remove pollutants from aqueous solution. The operating parameters were the contact time, Fe initial concentration, adsorbent thickness, and adsorbent dose. The results ...
A conventional sequencing batch reactor (SBR) was upgraded using fixed biofilm
carriers with a sp... more A conventional sequencing batch reactor (SBR) was upgraded using fixed biofilm carriers with a specific surface area around 18 m2 m−3. The upgraded SBR was investigated to remove phenol from high strength wastewater operated under various operational conditions. The operational conditions used were variable volume exchange ratio (VER) up to 75%, hydraulic retention time (HRT) from (10.7–21.3 hr), aeration time (from 2 to 8 hr), and initial phenol concentration up to 600 mg L−1. It was found that the upgraded SBR increased the removal efficiencies of biological oxygen demand (BOD5), chemical oxygen demand (COD), and total suspended solids (TSS) by about 10% using high strength wastewater without phenol compared to SBR. Furthermore, the removal rate of phenol for the upgraded SBR was higher than conventional SBR by about 18% at 600 mg L− of initial phenol concentration under the same operational conditions. Compared to the conventional SBR, the upgraded version reduced the aeration step by 25% and achieved higher removal efficiency of phenol. Moreover, it reduced the excess sludge by about 23% and enhanced its properties by lowering the sludge volume index (SVI) by about 33%.
Bulletin of the Faculty of Engineering. Mansoura University
A raw wastewater has been treated in wastewater treatment plant of Met Abo El-Kom city using atta... more A raw wastewater has been treated in wastewater treatment plant of Met Abo El-Kom city using attached growth systems. The treatment was accomplished using an Aerated Fixed Film Reactor (AFFR) with plastic plates or plastic plates with plastic mesh. The first reactor consisted of a number of biofilm carriers from fiber glass plates. Another modified (AFFAR) has been used by modifying the first one by attaching plastic mesh to enhance biofilm area. The system was run in the field for more than six months. Practically, the system consistsed of four stages as with bafflers at hydraulic loading rate (HLR) of 0.1 and 0.2 m 3 /m 2 /d. The results showed under HLR= 0.1 m 3 /m 2 /d for the first reactor has achieved a removal efficiency of 89%, 95%, 90% and 93% for COD, BOD 5 , NH 3 and TSS respectively. However, the second modified reactor achieved high removal efficiency more than the first one because of the large biofilm area. The second reactor has achieved a removal efficiency of 94%, 98%, 95% and 97 for COD, BOD 5 , NH 3 and TSS respectively. The influent BOD 5 has been decreased from of 600 to 7 mg/l with removal percentage 98%. Removal of COD and SS was almost similar to that of BOD. The initial COD and SS of 800 mg/l and 510 mg/l come down to 71 mg/l and 20 mg/l respectively. In addition, the present study illustrated that use of biofilm carrier (plastic plates) improve the growth of biomass above surface area of plates and have a relative large surface area in small volume. Results also indicated that better removal efficiency can be obtained in case of low hydraulic loading rate of 0.1m 3 /m 2 /d especially for BOD 5 and COD. While in case of modified AFFR the effluent improved BOD 5 , COD, NH 3 and TSS removal.
Bulletin of the Faculty of Engineering. Mansoura University
Filtration is the main process in water treatment plant. In this process the water passing throug... more Filtration is the main process in water treatment plant. In this process the water passing through some porous media (sand) to remove the suspended solids and impurities. In the beginning of filtration process, the head loss is small and it can be easily calculated by different empirical equations, but as the filter bed gets clogged, the head loss increases. The pilot plant was installed in sanitary engineering laboratory, Mansoura University. The operating conditions have five explanatory parameters. These parameters are filter depth, filtration rate, run time, influent turbidity, and alum dose. The filter depth was ranged from 80 to 140 cm and alum dose were ranged from 20 to 50 mg/lit. The rate of filtration was used in the range from 4 to 8 m/hr and the initial turbidities varied from 10 to 50 NTU. A mathematical model was obtained for head loss through deep bed sand filter with various operating conditions (filter depth, filtration rate, alum dose, run time, and initial turbidity).The proposed model yield highly accurate results with correlation coefficient (R 2) of 0.88. The proposed model showed that the most significant parameters on predicted head loss are the run time and filtration rate. Also, the simple proposed model can be easily and effectively used as a decision supporting tool for prediction of filtration run length.
The performance of a sludge blanket clarifier was evaluated and compared to conventional settlers... more The performance of a sludge blanket clarifier was evaluated and compared to conventional settlers under high levels of turbidity and algae in the field and experimentally. Field data of sludge blanket and conventional clarifier operation were observed simultaneously for the treatment of highly turbid water. In addition, a comparison was carried out on turbidity removal efficiency, algae removal, and sludge accumulation pattern. Finally, these systems were simulated in the laboratory and operated to treat turbid water with high levels of turbidity and algae up to 80 NTU and 109cells/l respectively. Field data confirmed that the sludge blanket clarifier equipped with upper sludge cones has a high removal efficiency of turbidity and algae, ease of use and has insignificant sludge accumulation compared to the conventional settler. Further, laboratory experiments have confirmed that sludge blanket clarifier is also very effective for the treatment of high algae concentrations up to 109ce...
Algae-blanket phenomenon has been observed inside a large-scale flat-bottom clarifier for water t... more Algae-blanket phenomenon has been observed inside a large-scale flat-bottom clarifier for water treatment. This phenomenon occurred after running the reactor under high concentration of algae (10 9 cells/l) for a long time especially in hot climate regions. Under that high algae concentration, pre-chlorination doses up to 4.0 mg/l was not sufficient to prevent algae accumulation inside the sludge blanket layer. So, a gradual accumulation of algae (such as Chlorella, Melosira, and Pediastrum) occurred inside the sludge blanket, converting the whole blanket, to algae blanket after a specific period. So, this phenomenon depends on the algae concentration of the raw water, pre-chlorination dose, and the environmental conditions. As soon as the algal blanket is formed, the clarifier's performance is affected negatively. Algae blanket depletes all chlorine in the upper layer above it resulting in an accumulation of green weeds in that layer, as well as decreases the removal efficiency of the clarifier drastically. Finally, total failure of the clarifiers occurs after a few days associated with filter clogging. However, laboratory experiments confirmed this phenomenon and recommended that daily shock dose using chlorine with a concentration of 6.0 mg/l for one hour can prevent algae accumulation inside the sludge blanket layer.
A complete graphical solution is obtained for the completely mixed biofilm-activated sludge react... more A complete graphical solution is obtained for the completely mixed biofilm-activated sludge reactor (hybrid reactor). The solution consists of a series of curves deduced from the principal equations of the hybrid system after converting them in dimensionless form. The curves estimate the basic parameters of the hybrid system such as suspended biomass concentration, sludge residence time, wasted mass of sludge, and food to biomass ratio. All of these parameters can be expressed as functions of hydraulic retention time, influent substrate concentration, substrate concentration in the bulk, stagnant liquid layer thickness, and the minimum substrate concentration which can maintain the biofilm growth in addition to the basic kinetics of the activated sludge process in which all these variables are expressed in a dimensionless form. Compared to other solutions of such system these curves are simple, easy to use, and provide an accurate tool for analyzing such system based on fundamental principles. Further, these curves may be used as a quick tool to get the effect of variables change on the other parameters and the whole system.
Large quantities of sludge are produced during water treatment processes. Recently, sludge has be... more Large quantities of sludge are produced during water treatment processes. Recently, sludge has been treated as waste and disposed of in landfills, which increases the environmental burdens and the operational cost. Therefore, sludge reuse has become a significant environmental issue. In this study, adsorption of copper ions (Cu2+) onto calcined sludge was investigated under various operational conditions (with varying temperature, Cu2+ initial concentration, pH, and sludge dosage). The prepared sludge material was characterized with transmission electron microscopy (TEM), X-ray diffraction (XRD), dynamic light scattering (DLS), and Brunauer-Emmett-Teller (BET) surface area. The sorption capacity of sludge was directly proportional to the initial Cu2+ concentration and inversely proportional to the sludge dosage. The optimum operational pH and solution temperature were 6.6 and 80°C, respectively. The experimental results followed a Langmuir isotherm and pseudo-first-order adsorption kinetics. Thermodynamic parameters such as activation energy, change in free energy, enthalpy, and entropy were calculated. Thermodynamic analyses indicated that the sorption of copper ions onto the calcined sludge was driven by a physical adsorption process. The prepared sludge was proven to be an excellent adsorbent material for the removal of Cu2+ from an aqueous solution under optimum conditions.
There are some sources of pollution of the groundwater such as the industrial, agriculture, domes... more There are some sources of pollution of the groundwater such as the industrial, agriculture, domestic activities and the oxidation ponds that are considered collection points for waste disposal plants. The motivations to do this work were: (1) investigating the concentrations of pollutants in the oxidation ponds and well surrounding the 10th Ramadan city and (2) predicting the groundwater flow and the pollutant transport to the groundwater from the pollution source using a numerical simulation (MODFLOW-2000 with MT3D code). The samples of groundwater were collected from the wells that spread around the studied area as well as many samples were collected from the oxidation ponds to investigate the concentrations of pollutants in these samples and predict the pollutant transport to the groundwater over 30 years. The results illustrated that the ion concentration of most samples from the oxidation ponds resources contained Al 3+ , Fe 2+ , Sr 2+ , Ni 2+ , and Cr 2+ which were exceeding the acceptable limit of WHO (International standards for drinking water, WHO, Geneva, 1996) standards. The results also demonstrated that most of the analyzed groundwater samples are polluted with strontium (Sr 2+), aluminum (Al 3+), and iron (Fe 2+). The simulation predicted that the pollutants movements toward the northeast of the study zone over a long-term period (30 years).
The present study was carried out to simplify existing biofilm one-dimensional models, which cons... more The present study was carried out to simplify existing biofilm one-dimensional models, which consider a single substrate as the limiting factor. Models of Suidan and Wang (1985) and Sáez and Rittmann (1988, 1992) were selected for the present study. Thus, modified expressions were developed for the first one, while the exact solution of the second one could be obtained. The modified expressions and the exact solution are short, simple, easy to use, and give reliable results in comparison to the original models. In addition, the proposed expressions and solution can be used instead of the graphical solutions, which are commonly used to solve the original models. Applicability of the developed expressions has been demonstrated through an illustrative example. The proposed expressions and the present study may be useful to simplify the description of biofilm in many systems such as completely mixed or fluidized-bed reactor for treatment of water or wastewater as well as the biofilm-activated sludge reactors. Moreover, the exact solution from this study can be used to establish the biofilm kinetics instead of using the curve-matching technique.
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Papers by Moharram Fouad
carriers with a specific surface area around 18 m2
m−3. The upgraded SBR was investigated to remove phenol from high strength wastewater operated under various operational conditions. The operational conditions used were variable volume exchange
ratio (VER) up to 75%, hydraulic retention time (HRT) from (10.7–21.3 hr), aeration
time (from 2 to 8 hr), and initial phenol concentration up to 600 mg L−1. It was found
that the upgraded SBR increased the removal efficiencies of biological oxygen demand
(BOD5), chemical oxygen demand (COD), and total suspended solids (TSS) by about
10% using high strength wastewater without phenol compared to SBR. Furthermore,
the removal rate of phenol for the upgraded SBR was higher than conventional SBR
by about 18% at 600 mg L−
of initial phenol concentration under the same operational
conditions. Compared to the conventional SBR, the upgraded version reduced the
aeration step by 25% and achieved higher removal efficiency of phenol. Moreover, it
reduced the excess sludge by about 23% and enhanced its properties by lowering the
sludge volume index (SVI) by about 33%.
carriers with a specific surface area around 18 m2
m−3. The upgraded SBR was investigated to remove phenol from high strength wastewater operated under various operational conditions. The operational conditions used were variable volume exchange
ratio (VER) up to 75%, hydraulic retention time (HRT) from (10.7–21.3 hr), aeration
time (from 2 to 8 hr), and initial phenol concentration up to 600 mg L−1. It was found
that the upgraded SBR increased the removal efficiencies of biological oxygen demand
(BOD5), chemical oxygen demand (COD), and total suspended solids (TSS) by about
10% using high strength wastewater without phenol compared to SBR. Furthermore,
the removal rate of phenol for the upgraded SBR was higher than conventional SBR
by about 18% at 600 mg L−
of initial phenol concentration under the same operational
conditions. Compared to the conventional SBR, the upgraded version reduced the
aeration step by 25% and achieved higher removal efficiency of phenol. Moreover, it
reduced the excess sludge by about 23% and enhanced its properties by lowering the
sludge volume index (SVI) by about 33%.