REMOVAL OF ARSENIC FROM GROUNDWATER USING NATURALLY OCCURRING IRON OXIDES IN RURAL REGIONS OF MONGOLIA
Impact/Purpose:
A rural population of over a million in Inner Mongolia, one of the most disadvantaged regions in China, suffers serious health problems as a result of drinking water with arsenic concentrations as high as 1800 μg/L, which is 180 times over WHO’s drinking water guideline value. Because high arsenic concentrations are found in both shallow and deep wells and access to sanitized surface water and electricity is limited in this region, sustainable safe drinking water can only be supplied by effective removal of arsenic from groundwater. However, currently available methods for arsenic removal are unaffordable to the rural population where the average household income is in the range of 800-1200 RMB (about $100) per household per year. We aim to design a low-cost process for effective removal of arsenic from groundwater using naturally occurring iron-oxides that can be obtained at low prices in Inner Mongolia. The designed process has the potential to overcome the obstacles of previous methods and may be used affordably and on a small-scale, allowing for rapid dissemination into households in Inner Mongolia through collaboration with local governments and research institutions.
Description:
We have found that the iron oxide particles produced by grinding naturally occurring iron ores are very effective in removing arsenic from water. The arsenic adsorption isothermal of the particles has been characterized and an arsenic removal capacity of about 0.4 mg As/ g particle has been observed. This indicates that 1 pound of such particles is able to provide 30 gallons of arsenic-safe drinking groundwater in the arsenic-contaminated area of Mongolia by decreasing the arsenic concentration from about 1,800 μg/L to below 10 μg/L.
We have designed and made the magnet drum separator and optimized its performance using engineering design principles. The device can be operated in a continuous mode with only human power, and is able to process 1 gallon of water in 5 minutes. The water flow and the trajectory of the magnetic particles in the device have been simulated numerically to guide the design and operation of the device. Both experimental results and numerical modeling indicate that the magnetic particles can be efficiently separated from water and recovered by the magnet drum, and the concentrations of both the arsenic, the particles, and the iron in the treated water satisfy the WHO’s drinking water guideline value.
Students involved in the research have gained international views on the importance of clean water and sustainable engineering to the developing world. In addition, such research activities conducted by a US university improve the public awareness of arsenic contamination in drinking water and provide decision-makers in the surrounding communities of Mongolia with scientific information on the importance of clean drinking water.
We have established partnership with research institutions and universities in China and Mongolia, including (i) Shenyang Institute of Environmental Sciences (China) who has provided safe drinking water to more than 50,000 rural residents in the past 10 years, (ii) Tsinghua University (China), who has been our partner for international field study in China every summer for the past 5 years, and (iii) the National University of Mongolia (Mongolia), who has been our partner for the unique Mongolia Field Studies Program developed since its inception in 1998.
Record Details:
Record Type:PROJECT(
ABSTRACT
)
Start Date:10/01/2008
Completion Date:04/01/2009
Record ID:
200636
Keywords:
GROUND WATER, WATER PURIFICATION, ARSENIC REMOVAL, OXALIC ACID, HEMATITE, MAGNETITE, MAGNETIC PUMP,
Related Organizations:
Role
:OWNER
Organization Name
:UNIVERSITY OF PITTSBURGH - MAIN CAMPUS
State
:PA
Project Information:
Approach
:We propose to use magnetic particles of naturally occurring iron oxide as adsorbents to remove arsenic in groundwater. The magnetic iron oxide particles will be produced by grinding iron ores that are available at low prices in Inner Mongolia, and separated from non-magnetic materials using a magnet drum separator. The magnetic particles will be dispersed in water in a powder or sludge form to remove arsenic. The particles will be separated from water and recovered by a magnet drum separator after the treatment. The magnet drum separator is designed to be able to operate without the use of electricity or gasoline. The design team will develop a prototype of the magnet drum separator and demonstrate the arsenic removal process at the University of Pittsburgh, with Inner Mongolia groundwater and iron oxide samples obtained through collaboration with partners in China. The water treatment process and the magnet drum separator design will be optimized to improve the efficiencies of arsenic removal and recovery of iron oxides. With successful development of the prototype, a field test will be conducted in Inner Mongolia through collaboration with our partner in China.
Cost
:$9,999.00
Research Component
:Pollution Prevention/Sustainable Development
Approach
:We propose to use magnetic particles of naturally occurring iron oxide as adsorbents to remove arsenic in groundwater. The magnetic iron oxide particles will be produced by grinding iron ores that are available at low prices in Inner Mongolia, and separated from non-magnetic materials using a magnet drum separator. The magnetic particles will be dispersed in water in a powder or sludge form to remove arsenic. The particles will be separated from water and recovered by a magnet drum separator after the treatment. The magnet drum separator is designed to be able to operate without the use of electricity or gasoline. The design team will develop a prototype of the magnet drum separator and demonstrate the arsenic removal process at the University of Pittsburgh, with Inner Mongolia groundwater and iron oxide samples obtained through collaboration with partners in China. The water treatment process and the magnet drum separator design will be optimized to improve the efficiencies of arsenic removal and recovery of iron oxides. With successful development of the prototype, a field test will be conducted in Inner Mongolia through collaboration with our partner in China.
Cost
:$9,999.00
Research Component
:P3 Challenge Area - Water
Approach
:We propose to use magnetic particles of naturally occurring iron oxide as adsorbents to remove arsenic in groundwater. The magnetic iron oxide particles will be produced by grinding iron ores that are available at low prices in Inner Mongolia, and separated from non-magnetic materials using a magnet drum separator. The magnetic particles will be dispersed in water in a powder or sludge form to remove arsenic. The particles will be separated from water and recovered by a magnet drum separator after the treatment. The magnet drum separator is designed to be able to operate without the use of electricity or gasoline. The design team will develop a prototype of the magnet drum separator and demonstrate the arsenic removal process at the University of Pittsburgh, with Inner Mongolia groundwater and iron oxide samples obtained through collaboration with partners in China. The water treatment process and the magnet drum separator design will be optimized to improve the efficiencies of arsenic removal and recovery of iron oxides. With successful development of the prototype, a field test will be conducted in Inner Mongolia through collaboration with our partner in China.
Cost
:$9,999.00
Research Component
:P3 Challenge Area - Materials & Chemistry
Project IDs:
ID Code
:SU833934
Project type
:EPA Grant