Publications

Most updated publication list: Google Scholar.

Journal Articles

High organofluorine concentrations in municipal wastewater affect downstream drinking water supplies for millions of Americans

Published in Proceedings of the National Academy of Sciences of the United States of America, 2025

US municipal wastewater facilities are major per- and polyfluoroalkyl substances (PFAS) sources known to affect drinking water quality. Among eight large wastewater treatment facilities with comparable treatment technologies and sizes to those serving 70% of the US population, we found that the six regulated PFAS in drinking water accounted for <10% of extractable organofluorine (EOF) in wastewater influent and effluent. Most (62 to 75%) of the EOF consisted of commonly prescribed fluorinated pharmaceuticals, and the maximum EOF removal efficiency was <25%. Results from a national wastewater dilution model suggest that wastewater PFAS discharges impair drinking water supplies for >20 million Americans, emphasizing the importance of reducing diverse PFAS sources entering wastewater.

Multiple Data Imputation Methods Advance Risk Analysis and Treatability of Co-occurring Inorganic Chemicals in Groundwater

Published in Environmental Science & Technology, 2024

The study emphasizes the importance of accurately assessing and managing risks from inorganic pollutants in groundwater. Due to sparse historic water quality databases, evaluating exposure and treatment effectiveness is challenging. Two advanced data imputation techniques, AMELIA and MICE, were compared to fill gaps in groundwater quality data. AMELIA performed better, as MICE tended to overestimate values, creating more outliers. Field data showed 75-80% of samples had no co-occurring pollutants exceeding MCL values, while imputed data indicated only 15-55% posed no health risks. Imputed data revealed a significant increase in locations potentially exceeding health limits and identified samples with multiple co-occurring chemicals surpassing health levels. Linking imputed data to sampling locations helps identify hotspots and optimize resource allocation for further sampling and analysis. This approach aids state agencies in prioritizing sampling locations and chemicals, enhancing the impact of funding for groundwater data collection by reducing uncertainty in future sampling and analysis priorities.

Comparing household heads’ perception of climate change variability with meteorological trends and understanding mitigation measures to combat the adverse effects in coastal areas of Bangladesh

Published in SN Social Sciences, 2024

The study examines household heads’ perceptions of climate change and compares them with meteorological trends in Bangladesh’s coastal districts. Using a mixed-methods approach, data were collected from 164 household heads and analyzed alongside temperature and rainfall data from 1980 to 2015. The analysis showed significant temperature increases across all seasons, aligning with residents’ observations, while rainfall patterns were more variable. Survey results indicated strong community awareness of climate change, with respondents emphasizing the need for climate education specific to Bangladesh and the importance of community cooperation. Education and income were significant predictors of climate change perceptions, with higher levels linked to more informed views on mitigation strategies. The study highlights the alignment between local perceptions and scientific data, stressing the integration of indigenous knowledge with empirical evidence in climate resilience planning. It offers valuable insights for policymakers and practitioners focused on building resilient communities in vulnerable coastal regions.

Global-to-Local Dependencies in Phosphorus Mass Flows and Markets: Pathways to Improving System Resiliency in Response to Exogenous Shocks

Published in Environmental Science & Technology Letters, 2024

The study examines the vulnerability of phosphate (P) fertilizers to various exogenous shocks, such as commodity market fluctuations, extreme weather events, natural disasters, and geopolitical instability. It emphasizes the importance of understanding bidirectional risk transmission in P supply and consumption chains to prevent major impacts on critical infrastructure and global food systems. Recent unanticipated events and their cascading effects on P markets are highlighted, underscoring the need to consider these shocks in local assessments of P flows, policies, and infrastructure design. The text provides examples of strategies to enhance system resiliency, such as internal P recycling, improving plant P use efficiency, and utilizing legacy soil P. These local strategies, integrated within national and global policies, can mitigate risks and promote a sustainable P future.

Sucralose and Predicted De Facto Wastewater Reuse Levels Correlate with PFAS Levels in Surface Waters

Published in Environmental Science & Technology Letters, 2023

The study investigates the impact of per- and polyfluoroalkyl substances (PFAS) from wastewater treatment plant (WWTP) effluents on downstream drinking water treatment plants (DWTPs). PFAS, harmful to human health and ecosystems, are commonly found in WWTP effluents discharged into surface waters. The study analyzed river water and WWTP effluent samples for 19 PFAS and a surrogate chemical (sucralose) in a large watershed with over 165 WWTP discharges and multiple DWTP intakes. Results showed higher PFAS concentrations in WWTP effluents (50–200 ng/L) compared to river water, with similar distributions of individual PFAS in both. A direct linear relationship was found between PFAS and sucralose concentrations, indicating that unplanned wastewater reuse could be a significant PFAS source for many DWTPs. The study offers guidance for identifying PFAS sources through de facto reuse modeling and chemical surrogate sampling.

A sustainability analysis on the trends and frequency of the channel flow of a carp breeding river against human interventions and governing public–private partnership (PPP) as adaptation

Published in SN Applied Sciences, 2020

The study examines the impact of human interventions on the Halda River, Bangladesh’s only natural carp breeding ground, and proposes a public-private partnership (PPP) model to address its deteriorating condition. The river faces infrastructural obstructions, industrial and agricultural exploitation, and climate change impacts, such as high salinity intrusion. These factors obstruct river flow and harm carp habitats, especially during pre-monsoon periods. A sustainability analysis was conducted, revealing river encroachment affecting aquaculture and low water availability in key river stretches. Frequency analysis indicated that pre-monsoon flow is unsuitable for fish habitats. The study emphasizes the importance of conserving the Halda River due to its ecological and commercial significance and suggests that a PPP framework can ensure long-term sustainability. The proposed joint effort aims to manage the river’s ecosystem sustainably and provide economic benefits, with stakeholders working together for the river’s survival.

A sustainability study of the flow regulation impacts by dams in a carp breeding river using the hydrodynamic model and building block analysis

Published in SN Applied Sciences, 2019

The study addresses the threats to the Halda River, Bangladesh’s only natural carp spawning ground, due to human interventions and natural causes. These threats include pollution, infrastructural changes, and climate impacts. The study aims to assess the ecosystem, sustainable management, and flow regulation impacts of dams on the river. Using a hydrologic model (ArcSWAT) and a hydrodynamic model (Delft3D), the research simulates scenarios with and without dams to understand their effects on fish breeding conditions. The Tennant method is employed for environmental flow analysis, assessing impacts on fish habitats and spawning. The findings are further analyzed for velocity profiles to ensure sustainable aquatic habitats in the Halda River.

Minhazul Islam