AQUA — Water Infrastructure, Ecosystems and Society
Microcoleus sp. is a versatile microorganism widely available in the environment and easily cultu... more Microcoleus sp. is a versatile microorganism widely available in the environment and easily culturable. Hence, there is a progressing demand for wastewater treatment using this novel biosorption medium. The design of such a treatment method may be defined as an optimisation problem of algal dose and hydraulic retention time for attaining an adequate removal efficiency of heavy metals (Cr6+, Ni2+, and Zn2+) and nutrients (PO43- and NO3-). Batch experiments on synthetic wastewater were conducted for algal doses varying from 0.5 to 25 g/L and hydraulic retention times from 1 to 7 days. Significant removal efficiencies of greater than 90% were observed for the heavy metals, 75% of PO43- removal, and no removal of NO3- was found under continuous daylight. The single-factor ANOVA test confirms the statistical significance of the varying parameters on the pollutant removal efficiency. Langmuir and Freundlich's adsorption isotherms indicate satisfactory adsorption of the contaminants ab...
Improper wastewater management could result in significant damage to the treatment plants and the... more Improper wastewater management could result in significant damage to the treatment plants and the final recipient aquatic ecosystem. In the past, wastewater management did not get much attention from different stakeholders. However, recently a paradigm shift of wastewater and storm water management is evolving from a simple sanitary and flood control, respectively, to a whole environmental protection function. A very important aspect of the sewer systems management policy is to detect and eliminate an illicit intrusion. This PhD research is consisting of two main pillars. In the first pillar, the issues regarding the identification of an illicit intrusion in a sewer system have been addressed, proposing a source identification (SI) methodology. In the second pillar, different innovative methodologies have been proposed to find the optimal placement of a limited number of sensors in the sewer system. In the thesis, the SI is solved through a simulation-optimization model, combining t...
Increasing salinity is a crucial issue for the people of coastal regions in Bangladesh. To resolv... more Increasing salinity is a crucial issue for the people of coastal regions in Bangladesh. To resolve this problem, efficient and low-cost materials can be used as adsorbents to remove salinity from water. Among those, laterite soil (LS) is one of the efficient adsorbents in water treatment. This study demonstrates a low-cost salinity removal technique using laterite soil as adsorbent. The effect of burning temperature on raw laterite and synthetic laterite has been analyzed. The performance of the adsorbents has been observed in terms of efficiency in salinity removal. Both batch and column adsorption have been carried out to evaluate the adsorption capacity of raw LS and burned LS, respectively. Raw laterite shows maximum adsorption capacity of 21.24 mg/g in batch adsorption at an initial concentration of 900 mg/L. The optimum burning temperature for thermally treated LS has been found as 600 °C. However, SLS (Synthetic Laterite Soil) burned at 600 °C gives greater chloride ion remov...
Contamination source identification in water distribution network has got serious attention durin... more Contamination source identification in water distribution network has got serious attention during last two decades, especially in developed countries. The same effort is almost absent in developing countries. This paper introduces a contamination source identification methodology where EPANET is used for hydraulic and water quality simulation and genetic algorithm (GA) is used for the optimization. The methodology has been tested on two networks with increasing complexity. Sensitivity analysis on GA parameters shows the robustness of the methodology.<br>
Abstract A very important aspect in sewer systems management is represented by the detection of i... more Abstract A very important aspect in sewer systems management is represented by the detection of illicit intrusions, which recently supported the development of online sensors for wastewater quality monitoring. The present paper proposes a new methodology for characterizing an illicit intrusion in a sanitary or combined sewer system, using on-line pollutant concentration measurements. The source identification is formulated as an optimization problem, solved combining the hydraulic and quality simulation tool storm water management model (SWMM) with the GALib code. The methodology, which includes a pre-screening procedure useful for complex and large systems, is applied to a literature scheme and a real test-case, showing promising results. An uncertainty analysis is also performed for checking its robustness with respect to inflow uncertainty and in the presence of measurement errors.
Reed bed system (RBS) has potential to treat wastewater, and being interested on such green waste... more Reed bed system (RBS) has potential to treat wastewater, and being interested on such green wastewater infrastructures, a RBS has been installed for the first time in Bangladesh to treat faecal wastewater, which comes from a low-cost community latrine at a refugee camp in Cox's Bazar area. An anaerobic baffle reactor was set followed by RBS, which was operated continuously for four months at five different retention times (3–7 days). The RBS was found to retain, in average, about 92% of 5-day biochemical oxygen demand (BOD5) and chemical oxygen demand (COD), 69% of PO43- and 52% of NO3-. Importantly, the effluent concentration met the national environmental standard for all except for PO43-. Thus the optimum hydraulic retention time in RBS has been selected to be 3 day when the PO43- ion has been reduced at maximum rate. High positive correlation (p > 0.9) was observed between PO43-and NO3- concentration in effluent water as well. The results of this study, thus, partly suppo...
Wastewater quality monitoring is receiving growing interest with the necessity of developing new ... more Wastewater quality monitoring is receiving growing interest with the necessity of developing new strategies for controlling accidental and intentional illicit intrusions. In designing a monitoring network, a crucial aspect is represented by the sensors' location. In this study, a methodology for the optimal placement of wastewater monitoring sensors in sewer systems is presented. The sensor location is formulated as an optimization problem solved using greedy algorithms (GRs). The Storm Water Management Model (SWMM) was used to perform hydraulic and water-quality simulations. Six different procedures characterized by different fitness functions are presented and compared. The performances of the procedures are tested on a real sewer system, demonstrating the suitability of GRs for the sensor-placement problem. The results show a robustness of the methodology with respect to the detection concentration parameter, and they suggest that procedures with multiple objectives into a single fitness function give better results. A further comparison is performed using previously developed multi-objective procedures with multiple fitness functions solved using a genetic algorithm (GA), indicating better performances of the GR. The existing monitoring network, realized without the application of any sensor design, is always suboptimal.
Roads, highways and streets are fundamental infrastructure facilities to provide the transportati... more Roads, highways and streets are fundamental infrastructure facilities to provide the transportation for passenger travel and goods movement from one place to another in Sylhet, north-eastern division of Bangladesh with rapid growth of road vehicle, being comparatively developed economic tourist prone area faces severe road traffic accident. Such severe road accidents cause harsh safety hazards on the roads of Sylhet area. This research work presents an overview of the road traffic accident and degraded road safety situation in Sylhet zone which in particular, discusses the key road accident problem characteristics identifying the hazardous roads and spots, most responsible vehicles and related components, conditions of drivers and pedestrians, most victims of accident, effects of accident on society, safety priorities and options available in Sylhet. In this regard, a comprehensive questionnaire survey was conducted on the concerned groups of transportation and detailed accident data was collected from a popular local newspaper. Analysis of the study reveals that Dhaka-Sylhet highway is the most hazardous in road basis and Sylhet Sador thana is the most vulnerable in thana basis in Sylhet region.
Surma River is polluted day by day by human activities, poor structured sewerage and drainage sys... more Surma River is polluted day by day by human activities, poor structured sewerage and drainage system, discharging industrial and household wastes. The charas (natural channels) are responsible for surface runoff conveyance from its urban catchments to the receiving Surma River. Water samples have been collected from a part of Surma River along different points and analyzed for various water quality parameters during dry and monsoon periods. Effects of industrial wastes, municipal sewage, and agricultural runoff on river water quality have been investigated. The study was conducted within the Chattak to
A study of the water quality conditions of Sylhet city of Bangladesh and its restaurants was carr... more A study of the water quality conditions of Sylhet city of Bangladesh and its restaurants was carried out to assess risks to human health. The investigation was based on questionnaire survey of restaurants and laboratory tests on water samples obtained from the restaurants, tube wells of the city and Surma River the two main sources of water supply to the city. The test parameters were dissolved oxygen; conductance, hardness, pH, temperature, turbidity, essential and trace elements, dissolved and suspended solids and coliform bacteria. The quality of sanitary facilities and handling of food in the restaurants were also examined. It was found that the drinking water of each restaurant was contaminated with fecal coliforms and 25% restaurants had unsafe levels of iron in the water supply. Improper solid waste dumping was found as one of the reasons of groundwater pollution. Statistical analysis based on Pearson's correlation coefficient revealed significant correlation between the extent of groundwater pollution and dumping of solid waste effluents in the immediate vicinity of ground water (tube wells). It was observed that 75.69% (coefficient of determination r 2 = 0.7569) variation in the value of groundwater near the dumping place showed association with variation in the value of water quality within the dumping place. Health risk score for coliform bacteria was 1,474.77, indicating high risk. The results of the study help in enhancing awareness of health hazards of contaminated food among the consumers as well as in drawing attention of health regulatory authorities.
Fly ash is extensively used in concrete as an admixture in order to reduce cost of cement. For su... more Fly ash is extensively used in concrete as an admixture in order to reduce cost of cement. For sustainability in production of cement in Bangladesh, feasibility of fly ash generated from Barapukoria Power Plant was tested. This was used as an admixture with Shah Special cement in different proportion in order to reduce cost of cement and environmental pollution such as green house effect, problem of fly ash as solid waste. Laboratory test for different parameters such as compressive strength, workability of such mixtures were performed. The results show almost no sacrifice for the strength of cement due to mixture of fly ash with a proportion of 10%. The results show that curing of the even plain concrete in chloride environment is not desirable right from the time of demoulding
In this paper, an attempt is made to find out sustainable use of fly ash generated from Barapukor... more In this paper, an attempt is made to find out sustainable use of fly ash generated from Barapukoria Power Plant. This is used as an admixture with Shah Special Cement in 5%, 10% and 15% proportion. Laboratory test for different parameters such as compressive strength, workability, flexural strength, splitting tensile strength of such mixtures are carried out to find out optimum content. The results show almost no sacrifice for the strength of cement due to mixture of fly ash with a proportion of 10%.
A very important aspect in sewer systems management is represented by the detection of illicit in... more A very important aspect in sewer systems management is represented by the detection of illicit intrusions, which recently supported the development of online sensors for wastewater quality monitoring. The present paper proposes a new methodology for characterizing an illicit intrusion in a sanitary or combined sewer system, using on-line pollutant concentration measurements. The source identification is formulated as an optimization problem, solved combining the hydraulic and quality simulation tool storm water management model (SWMM) with the GALib code. The methodology, which includes a prescreening procedure useful for complex and large systems, is applied to a literature scheme and a real testcase, showing promising results. An uncertainty analysis is also performed for checking its robustness with respect to inflow uncertainty and in the presence of measurement errors.
AQUA — Water Infrastructure, Ecosystems and Society
Microcoleus sp. is a versatile microorganism widely available in the environment and easily cultu... more Microcoleus sp. is a versatile microorganism widely available in the environment and easily culturable. Hence, there is a progressing demand for wastewater treatment using this novel biosorption medium. The design of such a treatment method may be defined as an optimisation problem of algal dose and hydraulic retention time for attaining an adequate removal efficiency of heavy metals (Cr6+, Ni2+, and Zn2+) and nutrients (PO43- and NO3-). Batch experiments on synthetic wastewater were conducted for algal doses varying from 0.5 to 25 g/L and hydraulic retention times from 1 to 7 days. Significant removal efficiencies of greater than 90% were observed for the heavy metals, 75% of PO43- removal, and no removal of NO3- was found under continuous daylight. The single-factor ANOVA test confirms the statistical significance of the varying parameters on the pollutant removal efficiency. Langmuir and Freundlich's adsorption isotherms indicate satisfactory adsorption of the contaminants ab...
Improper wastewater management could result in significant damage to the treatment plants and the... more Improper wastewater management could result in significant damage to the treatment plants and the final recipient aquatic ecosystem. In the past, wastewater management did not get much attention from different stakeholders. However, recently a paradigm shift of wastewater and storm water management is evolving from a simple sanitary and flood control, respectively, to a whole environmental protection function. A very important aspect of the sewer systems management policy is to detect and eliminate an illicit intrusion. This PhD research is consisting of two main pillars. In the first pillar, the issues regarding the identification of an illicit intrusion in a sewer system have been addressed, proposing a source identification (SI) methodology. In the second pillar, different innovative methodologies have been proposed to find the optimal placement of a limited number of sensors in the sewer system. In the thesis, the SI is solved through a simulation-optimization model, combining t...
Increasing salinity is a crucial issue for the people of coastal regions in Bangladesh. To resolv... more Increasing salinity is a crucial issue for the people of coastal regions in Bangladesh. To resolve this problem, efficient and low-cost materials can be used as adsorbents to remove salinity from water. Among those, laterite soil (LS) is one of the efficient adsorbents in water treatment. This study demonstrates a low-cost salinity removal technique using laterite soil as adsorbent. The effect of burning temperature on raw laterite and synthetic laterite has been analyzed. The performance of the adsorbents has been observed in terms of efficiency in salinity removal. Both batch and column adsorption have been carried out to evaluate the adsorption capacity of raw LS and burned LS, respectively. Raw laterite shows maximum adsorption capacity of 21.24 mg/g in batch adsorption at an initial concentration of 900 mg/L. The optimum burning temperature for thermally treated LS has been found as 600 °C. However, SLS (Synthetic Laterite Soil) burned at 600 °C gives greater chloride ion remov...
Contamination source identification in water distribution network has got serious attention durin... more Contamination source identification in water distribution network has got serious attention during last two decades, especially in developed countries. The same effort is almost absent in developing countries. This paper introduces a contamination source identification methodology where EPANET is used for hydraulic and water quality simulation and genetic algorithm (GA) is used for the optimization. The methodology has been tested on two networks with increasing complexity. Sensitivity analysis on GA parameters shows the robustness of the methodology.<br>
Abstract A very important aspect in sewer systems management is represented by the detection of i... more Abstract A very important aspect in sewer systems management is represented by the detection of illicit intrusions, which recently supported the development of online sensors for wastewater quality monitoring. The present paper proposes a new methodology for characterizing an illicit intrusion in a sanitary or combined sewer system, using on-line pollutant concentration measurements. The source identification is formulated as an optimization problem, solved combining the hydraulic and quality simulation tool storm water management model (SWMM) with the GALib code. The methodology, which includes a pre-screening procedure useful for complex and large systems, is applied to a literature scheme and a real test-case, showing promising results. An uncertainty analysis is also performed for checking its robustness with respect to inflow uncertainty and in the presence of measurement errors.
Reed bed system (RBS) has potential to treat wastewater, and being interested on such green waste... more Reed bed system (RBS) has potential to treat wastewater, and being interested on such green wastewater infrastructures, a RBS has been installed for the first time in Bangladesh to treat faecal wastewater, which comes from a low-cost community latrine at a refugee camp in Cox's Bazar area. An anaerobic baffle reactor was set followed by RBS, which was operated continuously for four months at five different retention times (3–7 days). The RBS was found to retain, in average, about 92% of 5-day biochemical oxygen demand (BOD5) and chemical oxygen demand (COD), 69% of PO43- and 52% of NO3-. Importantly, the effluent concentration met the national environmental standard for all except for PO43-. Thus the optimum hydraulic retention time in RBS has been selected to be 3 day when the PO43- ion has been reduced at maximum rate. High positive correlation (p > 0.9) was observed between PO43-and NO3- concentration in effluent water as well. The results of this study, thus, partly suppo...
Wastewater quality monitoring is receiving growing interest with the necessity of developing new ... more Wastewater quality monitoring is receiving growing interest with the necessity of developing new strategies for controlling accidental and intentional illicit intrusions. In designing a monitoring network, a crucial aspect is represented by the sensors' location. In this study, a methodology for the optimal placement of wastewater monitoring sensors in sewer systems is presented. The sensor location is formulated as an optimization problem solved using greedy algorithms (GRs). The Storm Water Management Model (SWMM) was used to perform hydraulic and water-quality simulations. Six different procedures characterized by different fitness functions are presented and compared. The performances of the procedures are tested on a real sewer system, demonstrating the suitability of GRs for the sensor-placement problem. The results show a robustness of the methodology with respect to the detection concentration parameter, and they suggest that procedures with multiple objectives into a single fitness function give better results. A further comparison is performed using previously developed multi-objective procedures with multiple fitness functions solved using a genetic algorithm (GA), indicating better performances of the GR. The existing monitoring network, realized without the application of any sensor design, is always suboptimal.
Roads, highways and streets are fundamental infrastructure facilities to provide the transportati... more Roads, highways and streets are fundamental infrastructure facilities to provide the transportation for passenger travel and goods movement from one place to another in Sylhet, north-eastern division of Bangladesh with rapid growth of road vehicle, being comparatively developed economic tourist prone area faces severe road traffic accident. Such severe road accidents cause harsh safety hazards on the roads of Sylhet area. This research work presents an overview of the road traffic accident and degraded road safety situation in Sylhet zone which in particular, discusses the key road accident problem characteristics identifying the hazardous roads and spots, most responsible vehicles and related components, conditions of drivers and pedestrians, most victims of accident, effects of accident on society, safety priorities and options available in Sylhet. In this regard, a comprehensive questionnaire survey was conducted on the concerned groups of transportation and detailed accident data was collected from a popular local newspaper. Analysis of the study reveals that Dhaka-Sylhet highway is the most hazardous in road basis and Sylhet Sador thana is the most vulnerable in thana basis in Sylhet region.
Surma River is polluted day by day by human activities, poor structured sewerage and drainage sys... more Surma River is polluted day by day by human activities, poor structured sewerage and drainage system, discharging industrial and household wastes. The charas (natural channels) are responsible for surface runoff conveyance from its urban catchments to the receiving Surma River. Water samples have been collected from a part of Surma River along different points and analyzed for various water quality parameters during dry and monsoon periods. Effects of industrial wastes, municipal sewage, and agricultural runoff on river water quality have been investigated. The study was conducted within the Chattak to
A study of the water quality conditions of Sylhet city of Bangladesh and its restaurants was carr... more A study of the water quality conditions of Sylhet city of Bangladesh and its restaurants was carried out to assess risks to human health. The investigation was based on questionnaire survey of restaurants and laboratory tests on water samples obtained from the restaurants, tube wells of the city and Surma River the two main sources of water supply to the city. The test parameters were dissolved oxygen; conductance, hardness, pH, temperature, turbidity, essential and trace elements, dissolved and suspended solids and coliform bacteria. The quality of sanitary facilities and handling of food in the restaurants were also examined. It was found that the drinking water of each restaurant was contaminated with fecal coliforms and 25% restaurants had unsafe levels of iron in the water supply. Improper solid waste dumping was found as one of the reasons of groundwater pollution. Statistical analysis based on Pearson's correlation coefficient revealed significant correlation between the extent of groundwater pollution and dumping of solid waste effluents in the immediate vicinity of ground water (tube wells). It was observed that 75.69% (coefficient of determination r 2 = 0.7569) variation in the value of groundwater near the dumping place showed association with variation in the value of water quality within the dumping place. Health risk score for coliform bacteria was 1,474.77, indicating high risk. The results of the study help in enhancing awareness of health hazards of contaminated food among the consumers as well as in drawing attention of health regulatory authorities.
Fly ash is extensively used in concrete as an admixture in order to reduce cost of cement. For su... more Fly ash is extensively used in concrete as an admixture in order to reduce cost of cement. For sustainability in production of cement in Bangladesh, feasibility of fly ash generated from Barapukoria Power Plant was tested. This was used as an admixture with Shah Special cement in different proportion in order to reduce cost of cement and environmental pollution such as green house effect, problem of fly ash as solid waste. Laboratory test for different parameters such as compressive strength, workability of such mixtures were performed. The results show almost no sacrifice for the strength of cement due to mixture of fly ash with a proportion of 10%. The results show that curing of the even plain concrete in chloride environment is not desirable right from the time of demoulding
In this paper, an attempt is made to find out sustainable use of fly ash generated from Barapukor... more In this paper, an attempt is made to find out sustainable use of fly ash generated from Barapukoria Power Plant. This is used as an admixture with Shah Special Cement in 5%, 10% and 15% proportion. Laboratory test for different parameters such as compressive strength, workability, flexural strength, splitting tensile strength of such mixtures are carried out to find out optimum content. The results show almost no sacrifice for the strength of cement due to mixture of fly ash with a proportion of 10%.
A very important aspect in sewer systems management is represented by the detection of illicit in... more A very important aspect in sewer systems management is represented by the detection of illicit intrusions, which recently supported the development of online sensors for wastewater quality monitoring. The present paper proposes a new methodology for characterizing an illicit intrusion in a sanitary or combined sewer system, using on-line pollutant concentration measurements. The source identification is formulated as an optimization problem, solved combining the hydraulic and quality simulation tool storm water management model (SWMM) with the GALib code. The methodology, which includes a prescreening procedure useful for complex and large systems, is applied to a literature scheme and a real testcase, showing promising results. An uncertainty analysis is also performed for checking its robustness with respect to inflow uncertainty and in the presence of measurement errors.
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Papers by Bijit Banik