Zahid Aziz Ph.D. Candidate Dept of Earth and Environmental Sciences Columbia University in the City of New York 2971 Perry Ave, Fl 2 Bronx, NY 10458 Email: aziz@ldeo.columbia.edu Phone: 1-917-747-8925 Website: http://www.ldeo.columbia.edu/~aziz/ EDUCATION Doctorate of Philosophy in Geological Sciences Defended 05/2010 Columbia University, New York, NY Concentration: Hydrology and Geochemistry Dissertation Topic: Hydrology and Arsenic Contamination in Shallow Aquifers of Bangladesh Master of Arts in Geological Sciences 10/2005 Columbia University, New York, NY Master of Science in Geology 09/2000 University of Dhaka, Dhaka, Bangladesh Bachelor of Science in Geology 09/1998 University of Dhaka, Dhaka, Bangladesh RESEARCH Earth and Environmental Sciences, Columbia University, New York, NY 2003-2010 Spatial distribution of As: The spatial distribution of groundwater arsenic in Bangladesh is extremely heterogeneous and my research focused on understanding the origin of this variability. We compared As concentrations in groundwater with the type of surface soils inferred from shallow geophysical method. The comparison revealed a link between dissolved arsenic and near surface sediment type reflecting the surface permeability- dissolved As tend to be lower underlying sandy soils and higher capped by clayey soils. The association between dissolved As and near surface sediment suggests that the spatial distribution of dissolved As in shallow aquifers is controlled by surface recharge. The relationship provides a useful tool for locating areas with a low probability of arsenic contaminated groundwater that offers a hope of reducing the exposure to arsenic. Sulfur induced sequestration of As: Aside from reductive dissolution of iron oxyhydroxides, the desorption of arsenic following reduction from arsenate to arsenite is often invoked as the other leading cause of high arsenic levels in groundwater of Bangladesh. However, my study suggests that reduction of arsenic accompanied by sulfate reduction play a crucial role in retaining arsenic in sediments. Detailed groundwater monitoring of shallow wells (6-9 m) and X-ray absorption of Zahid Aziz p. 1 of 6
sediments at the same depths pointed out that reducing conditions will promote the sequestration of As in sediment possibly as realgar (AsS) or orpiment (As 2 S 3 ) when abundant sulfur is present. These findings challenge the prevailing view that arsenic levels are relatively low in shallow aquifers of Bangladesh due to insufficient reductive dissolution of iron hydroxides. Sulfide trapping may also have contributed to the broad relationship between the permeability of surface soils and the As content of shallow aquifers. Impact of irrigation pumping: Impact of irrigation pumping on the spatial distribution of arsenic is discussed by several researchers and is the subject of active debate among the researchers. Monitoring of nests of very shallow (6-9 m deep) multilevel wells in two contrasting areas of Araihazar, Bangladesh (heavy irrigation vs little/no irrigation) indicates that the irrigation pumping intensifies the recharge process and decreases arsenic concentrations in shallow aquifers by flushing and/or supplying sulfate into shallow aquifers. Hydrologic control on the distribution of As: The distribution of dissolved arsenic in shallow aquifers of Bangladesh can be heterogeneous down to the 10 2 m scale laterally and 10 0 m vertically. We examined by using a 3-D groundwater flow and transport model to what extent this variability can be explained by the cumulative effect of groundwater flow and sorptive exchange of As. The site selected for this study encompasses an area of 0.35 km 2 and is bounded by an impermeable clay layer and a stream over 80% of its perimeter. The model demonstrated that desorption, adsorption and flushing appear to control the evolution of As concentrations on a 100-1000 yr timescale in shallow aquifers. The model predicted a variable flushing rate of As controlled by the subsurface distribution of hydraulic conductivity and the recharge and discharge. The model also predicted a faster decrease in As concentrations by rapid flushing reducing people s exposure to arsenic. Fecal contamination in groundwater: Simultaneous monitoring of pathogen (total coliform and E. coli) concentrations in groundwater, river and pond suggested that the seasonal recharge from local surface water bodies causes microbial contamination in shallow aquifers. Aside from this study, I have investigated the performance of SONO As-removal system approved by the government and deployed by UNICEF in Shahrasti, Bangladesh where As levels are particularly high. The survey showed that the two third of SONO systems failed. Water analysis shows that the phosphate and dissolved organic carbon levels in groundwater of Shahrasti are particularly high and might be contributing to the filter failures. Department of Geology, University of Dhaka, Dhaka, Bangladesh 1998-2000 Identified and categorized fluvial landforms using satellite images, GIS and remote sensing technique. This study also described the avulsions of rivers in the western part of the Ganges Delta. EXPERIENCE Earth and Environmental Sciences, Columbia University, New York, NY Teaching Assistant 2005-2006 Earth and Human System: Advised students on class projects, assembled reading materials. Chemical Oceanography: Assisted in grading, class lectures and home works. Zahid Aziz p. 2 of 6
Department of Geology, University of Dhaka, Dhaka, Bangladesh Associate Research Scientist 2000-2002 Study Title: Assessment of consequences of saline water intrusion and land erosion on the coastal ecosystem of Bangladesh funded by Bangladesh Environmental Management Project, Dept. of Environment (BEMP). Calculated coastal erosion rate, delineated the extent of the saline water intrusion, prepared project reports. Study Title: Study on Groundwater Salinity and its Effect on Soil and the Crop Productivity in around Manda Thana, Naogaon, Bangladesh funded by the National Science and Technology of Bangladesh (NST). Organized and supervised field works, collected and analyzed soil/plant/ groundwater samples for major and trace elements, conducted resistivity survey and aquifer test. Research Assistant 1998-1999 Study Title: Flood 1998 and Its Biophysical Impact and Siltation Problem in the Riverbeds of Bangladesh funded by the National Science and Technology of Bangladesh (NST). Carried out questioner survey, analyzed data, and prepared maps. HONORS Faculty Fellowship: Columbia University, New York, NY 2003-2010 Fogarty Fellowship: Fogarty International Center, NIH 2003-2010 Merit Scholarship: University of Dhaka, Dhaka, Bangladesh 1996-2000 SKILLS Groundwater Modeling Surface and Groundwater Interaction: Simulated surface and groundwater interaction using Modflow. Temporal and Spatial Variability: Explained the temporal and spatial variability in groundwater chemistry using Modflow and MT3DMS. Contaminant Transport: Predicted transport and fate of arsenic in shallow aquifers using MT3DMS. Field/Hydrogeological Investigation Surface/Groundwater Collection: Stable isotopes, 3 H and He isotopes, SF 6, noble gases, major and trace elements Soil/Sediment Collection: Soil and sediment cores for chemistry and mineralogy Gas Collection: Noble gases, SF 6 in soils Field Measurement: Pumping test, slug test, geophysical survey Zahid Aziz p. 3 of 6
Well Monitoring: Drilling supervision, installation of wells, water level measurement Data acquisition equipment: Level logger, weather station etc tracking and maintenance GIS and Remote Sensing Spatial Analysis: Evaluated spatial relationship between arsenic concentrations in tube wells and soil types using ArcGIS, and Surfer. Fluvial Landform Characterization: Identified and categorized fluvial landforms using Erdas Imagine and ArcView. Coastal Erosion Rate: Calculated coastal erosion rate using ArcGIS and Erdas Imagine. Extent of Saline Groundwater: Determined the extent of saline groundwater using ArcGIS. Laboratory Water Sample Analysis: Major ions, trace elements, stable isotopes and organic carbons using ion chromatography (IC), mass spectrometry (ICPMS) and total organic carbon (TOC) Analyzer. Soil and Plant Sample Analysis: Major chemical constituents and trace elements. Computer Groundwater Modeling: Modflow, MT3DMS, PEST, GMS 6.5, PMWIN Hydrogeological: AquaChem, Rockworks GIS and Remote Sensing: ArcGIS, ArcView, ArcPad, Surfer, Erdas Imagine Statistics: MatLab, R-project, Geostatistics (GS+) Application: MS Office, Adobe Photoshop, Illustrator Languages Bengali (native), proficient in conversational Hindi and Urdu. TRAINING 29CFR1910.120 OSHA certification (OSHA 40 hr HAZWOPER) 02/ 2009 29CFR1910.120 OSHA certification (OSHA 8 hr Annual Refresher Course) 02/ 2010 ACADEMIC SERVICE Exhibitor, LDEO s Annual Open House, Columbia University 2003-2008 Demonstrated a class room model of Hydrologic Cycle and addressed soil and water contamination related issues to public. AFFILIATIONS American Association for the Advancement of Science (AAAS) Geological Society of America (Hydrogeology Division) Zahid Aziz p. 4 of 6
SELECTED PUBLICATIONS Z. Aziz, A. van Geen, R. Versteeg, A. Horneman, Y. Zheng, S. Goodbred, M. Steckler, M. Stute, B. Weinman, I. Gavrieli, M.A. Hoque, M. Shamsudduha, K.M. Ahmed (2008) Impact of local recharge on arsenic concentrations in shallow aquifers inferred from the electromagnetic conductivity of soils in Araihazar, Bangladesh, Water Resour. Res., 44, W07416, doi:10.1029/2007wr006000. Z. Aziz, B.C. Bostick, Y. Zheng, M.R. Huq, M.M. Rahman, K.M. Ahmed, and A. van Geen (in revision) Decoupling of arsenic and phosphate in shallow groundwater of Bangladesh by reduced sulfur. Environ Sci Technol. A. van Geen, Z. Aziz, A. Horneman, B. Weinman, R.K. Dhar, Y. Zheng, S. Goodbred, R. Versteeg, A.A. Seddique, M. A. Hoque, K.M. Ahmed (2006) Preliminary evidence of a link between surface soil properties and the arsenic content of shallow groundwater in Bangladesh, Journal of Geochemical Exploration. 88 (1-3): 157-161. A. van Geen, K. Radloff, Z. Aziz, Z. Cheng, M.R. Huq, K.M. Ahmed, B. Weinman, S. Goodbred, H.B. Jung, Y. Zheng, M. Berg, P.T.K. Trang, L. Charlet, J. Metral, D. Tisserand, S. Guillot, S. Chakraborty, A.P. Gajurel, B.N. Upreti (2008) Comparison of arsenic concentrations in simultaneously-collected groundwater and aquifer particles from Bangladesh, India, Vietnam, and Nepal, Applied Geochemistry 23, 3244-3251. A. van Geen, Y. Zheng, Z. Cheng, Z. Aziz, A. Horneman, R.K. Dhar, B. Mailloux, M. Stute, B. Weinman, S. Goodbred, A.A. Seddique, M.A. Hoque, K.M. Ahmed (2006) A transect of groundwater and sediment properties in Araihazar, Bangladesh: Further evidence of decoupling between As and Fe mobilization. Chemical Geology, 228(1-3): 85-96. B. Weinman, S. Goodbred Jr, Y. Zheng, Z. Aziz, A. Singhvi, Y.C. Nagar, S. Steckler, A. van Geen (2008) Controls of floodplain stratigraphy and evolution on the distribution of shallow groundwater arsenic in Araihazar, Bangladesh. GSA Bulletin 120, 1567 1580 A. van Geen, Y. Zheng, S. Goodbred Jr., A. Hornman, Z. Aziz, Z. Cheng, M. Stute, B. Mailloux, B. Weinman, M. A. Hoque, A.A. Seddique, M.S. Hossain, S.H. Chowdhury and K.M. Ahmed (2008) Flushing history as a hydrogeological control on the regional distribution of arsenic in shallow groundwater of the Bengal Basin, Environ. Sci. Technol. 42 (7), 2283-2288. A. Horneman, A. van Geen, D. Kent, P.E. Mathe, Y. Zheng, R.K. Dhar, S. O'Connell, M.A. Hoque, Z. Aziz, M. Shamsudduha, A. Seddique, and K.M. Ahmed (2004) Arsenic mobilization in Bangladesh groundwater decoupled from dissolution of iron oxyhydroxides. Part I: Evidence from borehole cuttings, Geochimica et Cosmochimica Acta, vol 68, No.17, pp 3459-3473. Manuscripts in Preparation Z. Aziz, A. van Geen, M. Stute, M.W. Rahman, M. M. Rahman, M.R. Huq, K.M. Ahmed (in prep) Declining groundwater As concentration in a very shallow aquifer of Bangladesh: natural forcing or irrigation pumping?. Z. Aziz, M. Stute, R. Versteeg, M.R. Huq, K.M. Ahmed, A. van Geen (in prep) Distribution of As in Bangladesh aquifers controlled by desorption and flushing: An evaluation at the village-scale using a 3-D groundwater flow model ABSTRACTS & PRESENTATIONS Aziz Z, van Geen A., Stute M., Rahman M.W., Rahman M.M., Huq M.R., Ahmed K.M. The Hydrology of Shallow Aquifers in Araihazar, Bangladesh: A Potential Link to Temporal Variability in Dissolved Arsenic Zahid Aziz p. 5 of 6
Concentrations. Oral Presentation. Session on Groundwater Arsenic: A Global Environmental Health Problem and Sustainable Mitigation I (297-4, T149) at the Geological Society of America 2008 Annual Meeting. George R. Brown Convention Center, Houston, TX. October 8, 2008. Aziz Z., van Geen A., Stute M, Versteeg R., Horneman A., Zheng Y., Goodbred S., Steckler M., Weinman B., Gavrieli I., Hoque MA., Shamsudduha M., K.M. Ahmed KM. Impact of local recharge on arsenic concentrations in shallow aquifers inferred from the electromagnetic conductivity of soils in Araihazar, Bangladesh. Oral Presentation. 2 nd International Congress, Arsenic in the environment. Session: Arsenic in rocks, soils, groundwater and air. Valencia, Spain. 21-23 May 2008. Aziz Z., van Geen A., Stute M., Zheng Y., Bostick BC., Rahman MW., Rahman MM., Huq MR., Ahmed KM. A new mechanism for arsenic removal from shallow aquifers of Bangladesh linked to local hydrology. Oral Presentation. Columbia Superfund Basic Research Program Monthly Seminar Series. New York. December 17 2007. Aziz Z., van Geen A., Stute M., Cheng Z., Rahman MW., Rahman MM, Ahmed KM. The Hydrology of Shallow Aquifers in Araihazar, Bangladesh: A Potential Link to Temporal Variability in Dissolved Arsenic Concentrations. Poster Presentation. Workshop on Arsenic in Groundwaters of South-East Asia: With Emphasis on Cambodia & Vietnam Joint organizers: Michael Berg (EAWAG, Switzerland) and David Polya (University of Manchester, UK). Manchester, UK 29th & 30th October 2007 Aziz Z., van Geen A., Stute M., Cheng Z., Rahman MW., Rahman M., Ahmed KM. Temporal variability in arsenic concentrations in shallow groundwater: the role of local hydrology. Poster Presentation. Session on Distribution of Arsenic and Related Metalloids in Surface and Ground Waters: Controls and Challenges at the Geological Society of America 2006 Annual Meeting. Pennsylvania Convention Center, Philadelphia. October 23, 2006. van Geen A, Aziz Z, Goodbred SL, Zheng Y, Horneman A, Dhar RK, Weinman B, Cheng Z, Stute M, Hoque MA, Seddique AA, and Ahmed KM. Regional and Local Control of Arsenic Concentrations in Shallow Aquifers by the Permeability of Surface Soils. Oral Presentation. Session on Arsenic in the Environment at American Geophysical Union's Fall 2004 Meeting. Moscone Center, San Francisco. December 15, 2004. Zahid Aziz p. 6 of 6