Muhammad Ashraf Ali

• PhD
• Professor (Full) at Bangladesh University of Engineering and Technology

Over the last several decades, much of population of Bangladesh and West Bengal switched their water supply from surface water to groundwater. Tragically, much of the region's groundwater is dangerously contaminated by arsenic, and consumption of this water has already created severe health effects. Here we consider how groundwater flow may affect...

This study investigates microplastics pollution in the water and bed sediment of a peripheral river of Dhaka city focusing on the possible impact of land use on the abundance and characteristics of microplastics. Water and sediment samples were collected from four locations along the river representing commercial, residential, industrial, and agric...

Scaling due to the precipitation of CaCO3 in water distribution systems results in flow restrictions and head loss, damage to plumbing fixtures, and clogging membranes/filters in treatment systems. A potential method for controlling CaCO3 precipitation is using scale inhibitors (e.g., PO43−, Zn2+, etc.). A recent study found that in NaCl electrolyt...

Changing ambient air temperature due to climate change can affect water quality in drinking water distribution systems (DWDS) in urban areas since several water quality parameters are temperature sensitive. In this study, we assessed how changing air temperature affects selected water quality parameters in DWDS. We predicted the ambient air tempera...

Groundwater is perceived as being less vulnerable to microbiological contamination than surface water, given the natural filtering ability of the subsurface. But several recent studies have reported fecal contamination in shallow groundwater of many regions of Bangladesh and several other countries. Leaching from latrine pits and soakage wells is c...

In recent times, Dhaka has been experiencing poor air quality. The critical air pollutant for Dhaka city is particulate matter (PM), particularly PM2.5 (PM that is 2.5 microns or less in width). The primary sources of PM2.5 are the emission from brick kilns, vehicles, industries, and dust re-suspension. According to previous studies, meteorological...

This paper presents a case study focusing on the impacts of combined sewer overflows on the water quality of the receiving water body, Hatirjheel. Hatirjheel, the largest surface water body in Dhaka City with an area of about 1.012 km², receives discharges from nine combined sewer overflow (CSO) structures. The water quality of Hatirjheel is poor t...

The concentration of criteria pollutants in the air indicates the level of air pollution. Among the criteria pollutants, ambient particulate matter (PM), especially PM2.5 (aerodynamic diameter less than 2.5 µm), is the primary concern in Dhaka city as most of the brick kilns and industries are in the vicinity of the city. Seasonal factors have a pr...

Today a world without plastics is unimaginable. But their non-biodegradability poses serious threat to the ecosystem, especially to the aquatic environment. Probable adverse effects of microplastics include adsorption of persistent organic pollutants, bio-accumulation, and death of various aquatic organisms, which eventually leads to loss of biodiv...

Precipitation of CaCO3 has long been a concern in water treatment/distribution systems; however, this problem has been identified only recently in some areas (e.g., Meherpur) of Bangladesh. Scaling is the most obvious manifestation of CaCO3 precipitation in water distribution systems, resulting in flow restrictions and head loss and accelerates equ...

Precipitation of CaCO3 has long been a concern in water treatment/distribution systems; however, this problem has been identified only recently in some areas (e.g., Meherpur) of Bangladesh. Scaling is the most obvious manifestation of CaCO3 precipitation in water distribution systems, resulting in flow restrictions and head loss and accelerates equ...

Poor air quality is a major concern in Dhaka city. In Dhaka, DoE has three Continuous Air Monitoring Station (CAMS) located at Sher-e-Bangla Nagar (CAMS-1), Farmgate (CAMS-2) and Mirpur (CAMS-3) where concentrations of "criteria pollutants" are measured. Recorded data show that ambient concentrations of PM and NO 2 significantly exceed the standard...

Widespread groundwater arsenic contamination in south, southwestern and northeastern regions and high salinity in the southwestern coastal region are the two major challenges for drinking water supply in Bangladesh. In this study, we assessed various water supply technologies used for mitigating arsenic and salinity in Laksam of Cumilla and Assasun...

Owing to the depletion of natural gas reserves and economic constraints of imported oil, Bangladesh plans on shifting to an electricity mix dominated by coal. Among a number of planned coal-fired power plants, five power plants each with 1320-MW generation capacity are expected to be installed by 2030 in areas within 5-km radius of Payra, situated...

Bangladesh has achieved remarkable success in reducing the prevalence of open defecation to almost zero, from as high as 34 per cent in 1990. However, significant disparity exists in sanitation coverage, with relatively low coverage and poor quality sanitation in poor communities. In addition, poor management of faecal sludge is leading to serious...

"Resilient and Inclusive WASH Technology Album" is a readily usable album with details of technologies including key features, suitability, challenges, important operation and maintenance requirements and detail drawings, so that it can be contextualized as necessary during of its use.

Manganese (Mn) and arsenic (As) are common natural groundwater contaminants and are present at concentrations much higher than the recommended drinking water guidelines. In this study, laboratory investigations were carried out to evaluate the effectiveness of three different types of manganese oxide (MnO 2 )-coated media in removing manganese and...

Polluted sediment bed can act as a secondary pollution source for the overlying water layer in pol-luted water bodies. This study investigates contaminant (selected nutrient and heavy metals) flux from the sediment of Tongi Khal (canal) through laboratory batch experiments. The results of this research suggest that accumulated pollutants in bed sed...

This is an assessment report of performance of Biofil toilets in Rohingya camps. The study conducted by a team of ITN-BUET, with support from Oxfam and UNHCR.

Regular monitoring and systematic analysis of river water quality data is a prerequisite for the development of effective pollution prevention strategies to protect the rivers around the world. This study endeavours to assess the pollution status of two important rivers in Bangladesh by using a new water quality information system, FEWS-Bangladesh....

Ecosystem health of the peripheral rivers of Dhaka, the capital city of Bangladesh, has degraded significantly over the last few decades. Though some of these peripheral rivers are marked as Ecologically Critical Area (ECA) by the Government, there is no system in place for monitoring of water quality and ecosystem health of the rivers. In this stu...

Dhaka with a population density of around 23,234 per square kilometer is experiencing major health impacts resulting from poor air quality (World population review, n.d.). The aim of this study was to understand the trend of air quality of Dhaka city considering meteorological and seasonal influences. The critical air pollutant for Dhaka city is pa...

In Bangladesh, contribution of surface water in water supply is gradually increasing. Surface water currently accounts for about 22% of DWASA water supply, almost all of it comes from Saidabad Water Treatment Plant (SWTP). In response to high Fe, As and Mn in groundwater and lowering of groundwater table, surface water treatment plants (WTPs) have...

In Bangladesh, groundwater from shallow aquifer is widely used to irrigate dry season boro rice. But shallow aquifers in many regions are highly contaminated with arsenic (As). Reduction of As concentration of groundwater within irrigation channel could be an effective way to reduce arsenic loading in rice fields. Results from batch studies suggest...

In Bangladesh, the contribution of surface water to the water supply is increasing due to the lowering of groundwater level and excessive arsenic, iron, and manganese in groundwater. Surface waters bodies in Bangladesh are characterized by high concentration of organic matters, contributed by both domestic and industrial sources. The presence of or...

In any surface water body, sediments are the ultimate sink of many of the pollutants. Contaminated sediments can act as a secondary source of pollution for the overlying water, releasing pollutants by different physiochemical or biological processes. Anthropogenic activity like dredging can accelerate release of pollutants from sediment, thereby qu...

This column comprises notes and info not subjected to peer-review focusing on waste management issues in different corners of the world. Its aim is to open a window onto the solid waste management situation in any given country, major city or significant geographic area that may be of interest to the scientific and technical community. Bangladesh...

Climate-induced waterlogging has been significantly affecting the lives and livelihood of people in the south-west coastal region of Bangladesh for a couple of decades. The objective of this study is to investigate the waterlogging hazards of Tala, a south-western coastal Upazila of Bangladesh by analyzing satellite image. An empirical model based...

In Bangladesh, groundwater is the primary source of potable water. But it contains high concentration of arsenic, as well as iron and manganese in many regions. Arsenic and iron removal plants are used in many such areas. Previous studies have demonstrated effectiveness of coagulation (e.g., using alum and ferric chloride) process for removal of ar...

Condensate water generated from air conditioning system is often treated as wastewater and discharged to the building drainage system. In this study, controlled experiments have been carried out to assess generation of condensate water under different weather and operational conditions. The most important parameters affecting condensate water gener...

Considering the present scarcity of safe water in many urban areas, rainwater harvesting can be an effective alternative solution for water security of Bangladesh. To assess the rainwater quality at different stages of few urban rainwater harvesting systems (URWHS) and effectiveness of their filtration system to prevent contamination, WaterAid Bang...

Surface waters in Bangladesh and many developing countries are characterized by high concentrations of organic matter and ammonia, particularly during the dry season. In the presence of high concentration of ammonia, break point chlorination often becomes impractical at treatment plant because of very high chlorine dose requirements; therefore, "ch...

In Bangladesh water extracted from arsenic (As) contaminated shallow aquifer is extensively used for irrigating dry season (boro) rice fields. This practice is increasing As concentration in top-soils, resulting in elevated concentration of As in rice plants, decreased rice yield and increased human exposure to As. Efforts have been made to reduce...

Condensate water generated from air conditioning system is often treated as wastewater and discharged to the building drainage system. In this study, controlled experiments have been carried out to assess generation of condensate water under different weather and operational conditions. The most important parameters affecting condensate water gener...

In Bangladesh, groundwater is the primary source of potable water. But it contains high concentration of arsenic, as well as iron and manganese in many regions. Arsenic and iron removal plants are used in many such areas. Previous studies have demonstrated effectiveness of coagulation (e.g., using alum and ferric chloride) process for removal of ar...

Manganese (Mn) and arsenic (As) are common natural groundwater contaminants in Bangladesh and many other countries. WHO (2004) recommended health-based drinking water guideline values of0.4 mg/l and 0.01 mg/l for Mn and As, respectively. Removal of dissolved Mn by filtration through granular media (sand) could be an effective treatment method for M...

The specific objectives of the study were to assess available water options for mitigation of arsenic problem and salinity problem in selected areas of Bangladesh (arsenic affected Laksam, Comillaand salinity-affected Assasuni, Satkhira).

In Bangladesh water extracted from arsenic (As) contaminated shallow aquifer is extensively used for irrigating dry season (boro) rice fields. This practice is increasing As concentration in top-soils, resulting in elevated concentration of As in rice plants, decreased rice yield and increased human exposure to As. Efforts have been made to reduce...

This book is the culmination of the hard work of a number of experts who have long been championing the rainwater harvesting, and reflects a growing body of knowledge that is indigenous, experiential, and of fundamental importance to the sustainability of our country’s scarce water resources. It got published on the occasion of 3rd Bangladesh conve...

Surface waters in Bangladesh and in many developing countries are characterized by high concentrations organic matter and ammonia, particularly during the dry season. These waters are often used as raw water for surface water treatment plants. In the presence of high concentration of ammonia, break point chlorination often becomes impractical becau...

The results of a study on the type and quantity of solid wastes generated in a rural vegetable and cattle market, and biogas generation from the waste are presented in this paper. The market wastes were collected; individual items were separated and measured on both normal days and haat days. During a normal day, it was found that very insignifican...

In Bangladesh, surface water (e.g., pond/river water) and rainwater are important sources of potable water, particularly in areas suffering from arsenic contamination of groundwater and high salinity. However, surface water often suffers from high microbial contamination and needs disinfection for potable use. Disinfection is a challenge for small...

Considering the increasing salinity intrusion in coastal areas, pollution of surface water bodies, groundwater contamination by arsenic and manganese, and groundwater depletion due to excessive withdrawal, rain water harvesting (RWH) has become a potential source of water supply in coastal and arsenic affected area in Bangladesh. A user-friendly so...

The research work presented in the poster evaluated potential of community based decentralized wastewater treatment systems evaluated from experiences gained at a locality in Khulna, Bangladesh. The specific objectives of this work involved: • System efficiency assessment considering different critical effluent discharge water quality parameters ac...

Except for about 20% area of Dhaka city (covered by virtually non-functional sewerage system), all urban areas of Bangladesh are served by on-site sanitation (OSS) system. However, OSS systems in Bangladesh have been developed without any consideration to the management of fecal sludge. Disposal of fecal sludge in low-lying areas and in lakes and c...

In Bangladesh, most surface water bodies are susceptible to contamination from disposal of untreated domestic and industrial wastewater. Surface water bodies receiving wastewater are characterized by low levels of DO and high concentrations of BOD, COD, Ammonia and other nutrients. Year-long monitoring of Hatirjheel water quality showed sustained h...

Bangladesh has witnessed a remarkable growth in on-site sanitation facilities throughout the country over the last decade. The major progress in urban sanitation during this period is the elimination of open defecation amongst the poorest quintile through use of on-site sanitation (OSS) facilities. However, the on-site sanitation systems in Banglad...

Extensive use of arsenic-contaminated well water for irrigation of rice fields in Bangladesh has led to elevated arsenic concentrations in rice plants, decreased rice yields, and increased human exposure to arsenic. The goal of this study was to investigate whether arsenic removal from irrigation water could be improved within distribution channels...

This paper aims at understanding the meteorological influences in ambient air quality of Dhaka city by analyzing air quality and meteorological data. Trends in air quality over the past decade show large seasonal variations in both PM2.5 and PM10 concentrations, exceeding the national standards during dry season, while remaining somewhat below the...

Manganese (Mn) is a common natural groundwater contaminant and high intake of Mn has adverse health impacts. Groundwater in many areas of Bangladesh exceeds the Mn standard for drinking water by a large margin. Thus, a cost-effective and efficient technology to remove Mn from groundwater is imperative for Bangladesh. Adsorption onto Mn-oxide coated...

Hatirjheel, which is now the largest surface water body within Dhaka, serves very important hydrologic functions of draining and detaining storm water from a large area of Dhaka city. As a part of a restoration project to save Hatirjheel from pollution and degradation, eleven especially designed sewage diversion structures (SSDSs) have been constru...

Laboratory incubations of sediment collected from an arsenic-contaminated aquifer in Bangladesh revealed a hitherto undocumented pool of biodegradable sedimentary organic carbon. Sampling, homogenizing, handling, and/or experimentation with the sediment released organic carbon, causing dissolved organic carbon (DOC) concentrations to reach 150–250...

The Saidabad Water Treatment Plant (SWTP) serves as a major potable drinking water source for the Dhaka city which faces high concentration of algae problem during dry season. This study evaluates the possible application of copper salt in controlling algae at the SWTP. In this study, the chemical speciation of copper has been assessed using the so...

This report provides database of fecal sludge management service providers and their ranking based on a set of criteria to identify the most eligible service providers for receiving capacity building support.

Arsenic-contaminated groundwater is widely used to irrigate dry-season rice (boro) in Bangladesh. This has greatly improved food security but is leading to increased As levels in soils and rice and may cause yield reductions in the long term. Owing to the gradual accumulation of As in paddy soil, the adverse effects of groundwater irrigation may al...

Across Bangladesh, dry-season irrigation with arsenic-contaminated well water is loading arsenic onto rice paddies, leading to increased arsenic concentrations in plants, diminished crop yields, and increased human health risks. As irrigation water flows through conveyance channels between wells and rice fields, arsenic concentrations change over s...

The effects of applied electric charge (0-200 Amp-min) and pH on the removal of colour and COD from textile wastewater have been analysed. Mild steel plates have been used as electrodes in both parallel and series connections. For colour and COD removal, four electrodes each with a surface area of 177.3 cm² and with inter-electrode distance of 2.3...

With increasing use of arsenic (As) removal units for treatment of As-contaminated groundwater in rural Bangladesh, concerns have been raised regarding safe disposal of the As-rich wastes from such units and possible contamination of the environment. In the absence of any clear guideline for safe disposal of wastes generated from As removal units,...

Huge quantities of untreated domestic and industrial wastes are being released everyday in Sitalakhya River, flowing along the eastern side of Dhaka City. The water quality of this river is deteriorating rapidly, especially during the dry season at certain reaches of the river. A one-dimensional quasi-steady state water quality model has been devel...

In Bangladesh, irrigation of dry season rice (boro) with arsenic-contaminated groundwater is leading to increased As levels in soils and rice, and to concerns about As-induced yield reduction. Arsenic concentrations and speciation in soil porewater are strongly influenced by redox conditions, and thus by water management during rice growth. We stud...

Dhaka, the capital of Bangladesh, has a population density of around 20,000 per square kilometer and faces the risk of large adverse health impacts due to poor air quality, particularly high particulate matter (PM) concentration. Government decisions aimed at curbing air pollution are usually taken on ad-hoc basis, primarily due to limited capacity...

Dhaka city with a population density of around 20,000 per square kilometer faces the risk of large adverse health impacts due to poor air quality. Government decisions aimed at curbing air pollution are usually taken on ad-hoc basis, primarily due to limited monitoring and limited capacity for analysis of options. There are currently only two conti...

Arsenic-contaminated groundwater is widely used to irrigate dry-season rice (boro) in Bangladesh. This has greatly improved food security but is leading to increased As levels in soils and rice and may cause As-induced yield reductions in the long term. Owing to the gradual accumulation of As in paddy soil [1,2], the adverse effects of groundwater...

In several districts of Bangladesh, over 80% of shallow tubewells (STWs) are affected by arsenic concentrations above 50 μg/L. Deep tubewells (DTWs) are among the preferred mitigation options for reducing exposure to arsenic. During field studies around the town of Sreenagar (30 km South of Dhaka) we collected water samples from existing STWs, DTWs...

In a three-year field study, we investigated the biogeochemical cycling of As in an irrigated rice paddy system in Munshiganj district, Bangladesh. Our objectives were (i) to understand the spatial distribution of As in irrigated rice fields, (ii) to quantify the gains and losses of As during irrigation and monsoon flooding, and (iii) to assess pos...

Over 85% of shallow tubewells (STWs) in the district of Mushiganj, Bangladesh, are affected by As concentrations above 50 μg/L. Deep tubewells (DTWs) are among the preferred mitigation options for reducing exposure to As. Around the town of Sreenagar (30 km South of Dhaka) water samples were collected from existing STWs and DTWs, monitoring wells (...

In Bangladesh, irrigation of dry season rice (boro) with arsenic-contaminated groundwater is leading to increased As levels in soils and rice, and to concerns about As-induced yield reduction. Arsenic concentrations and speciation in soil porewater are strongly influenced by redox conditions, and thus by water management during rice growth. We stud...

Irrigation of rice fields in Bangladesh with arsenic-contaminated groundwater transfers tens of cubic kilometers of water and thousands of tons of arsenic from aquifers to rice fields each year. Here we combine observations of infiltration patterns with measurements of porewater chemical composition from our field site in Munshiganj Bangladesh to c...

Groundwater rich in arsenic (As) is extensively used for dry season boro rice cultivation in Bangladesh, leading to long-term As accumulation in soils. This may result in increasing levels of As in rice straw and grain, and eventually, in decreasing rice yields due to As phytotoxicity. In this study, we investigated the As contents of rice straw an...

Adsorption and formation of Manganese (Mn) oxide coatings on filter media are thought to be responsible for Mn removal from groundwater; however limited information is available on factors affecting formation of such coatings. In this study, manganese oxide coated sand bed was prepared and factors affecting formation of Mn oxide coating on sand was...

Shallow groundwater, often rich in arsenic (As), is widely used for irrigation of dry season boro rice in Bangladesh. In the long term, this may lead to increasing As contents in rice paddy soils, which threatens rice yields, food quality, and human health. The objective of this study was to quantify gains and losses of soil As in a rice paddy fiel...