Red Soil Filtration System

BDCF is excited to announce that we have received multiple research grants, including the Rising Explorer Grant, to research and identify a low-cost engineering solution to arsenic poisoning prevention in rural regions of Bangladesh. Our study will primarily be focused on the Satkhira city in the Khulna Division.

Arsenic is an element from within the Earth’s crust and in its organic form, highly toxic. Arsenic-contaminated water is an exceedingly prevalent occurrence in rural areas. In these areas, families use tube wells to pump out groundwater, which is often contaminated. Because of this, over 200 million people drink high levels of arsenic-contaminated water. Arsenic poisoning causes complications such as diarrhea, affected hair and nails, darkened skin tone, and skin and bladder cancer. In Bangladesh, over 20 million people drink arsenic-contaminated water and over 43,000 people die from arsenic related illnesses annually. Cognitive-related conditions in children have been linked to arsenic poisoning as well.

However, the timing to address this problem is pertinent, as climate change is worsening the decades-long problem of arsenic poisoning in groundwater in Nadia, the West Bengal district with the most victims. As climate change reduces the rate at which rainwater seeps underground, the arsenic concentration is getting worse. The problems caused by arsenic contamination in drinking water are not only medical, but socio-economic as well. As children lose fathers, mothers, and their main bread-bringers to the effects of arsenic poisoning, they are left with no means to support themselves, often turning to slums. Local politicians in the village areas including Nadia deny any issues with groundwater despite the thousands of victims.

Arsenic poisoning in Bangladesh is an issue that is deeply tied to poverty, lack of healthcare, and corruption. It is imperative that an accessible solution is developed in order to bring forth change that will improve the lives of thousands, if not millions.

We are developing a novel filtration system, our Red Soil Filtration System (RSFS), which is economical for poverty-stricken populations to afford and maintains safe drinking water. The quality of life is improved for rural, low-income populations through this filtration system. The poor can drink safe water that will improve their quality of life, and the implementation of this filter in other villages can improve rural quality of life around the world. Our filter reduces arsenic levels of up to 500 ppb down to the Bangladeshi safe standard of 50 ppb. It is economically advantageous for poverty-stricken people, costing about 3 USD. The key material in this filter is laterite soil, which seems to be an acceptable replacement to the filter that currently is used, the SONO filter, which uses direct iron chips. Iron chips are costly, and the SONO filter is overall difficult to maintain. Because laterite soil, which contains iron, is readily available in that area, it means that villagers can use the natural resource they have without paying for iron chips.

The Red Soil Filtration System (RSFS) is made of 3 stacked buckets filled with coarse river sand, a 4-5 cm thick layer of a specifically designed composite iron matrix (CIM), charcoal, and wet brick chips. By pouring water through the buckets, large particles are filtered through the sand, arsenic is removed through chemical reactions in the composite iron matrix, and the charcoal and wet brick chips remove organics. 

When river water is poured into the buckets, several chemical reactions take place with Iron, (Fe), which allow for the key arsenic filtration to actually occur. Here are the two central reactions:

Equation 1: FeOH+H2AsO4- FeHAsO₄- + H₂O (K=1024)

Equation 2: FeOH+HAsO₄²- FeHAsO₄²- + H₂O (K=1029) 

In summary, the Red Soil Filtration System (RSFS) significantly reduces arsenic and is maintainable and affordable for poverty-stricken populations. It substitutes iron, a costly material inaccessible to Bangladeshi villagers, for laterite soil, a naturally occurring soil in village regions. It directly improves the lives of millions of underprivileged, uneducated village children, adults, and seniors in Bangladesh that have no option but to drink arsenic contaminated river water and groundwater.

Currently, we are working with the Liesgang firm to design patent the Red Soil Filtration System (RSFS) in Bangladesh. The incentive of well-being in all aspects of life and improved quality of life, along with a cheap, low-cost of the Red Soil Filtration System, will cause it to be a strong contender for the Bangladeshi government to implement into their villages as a solution for arsenicosis poisoning and death. With these robust incentives, the government and other private engineering companies will invest in mass production of the filtration system to be placed in rural villages. 

In addition, by raising awareness and funding, patenting the Red Soil Filtration System design in Bangladesh, a relatively low-cost process in comparison to typical Western patents, will improve its credibility for potential investors.