Thanks for sharing. Does anyone know what part and how they use it? article seems to suggest that it is used green as it is obtained from garden.

Cilantro, a favorite ingredient in salsas and other dishes, can absorb heavy metals from water, making it usable for drinking and irrigation. Conventional methods for removing heavy metals from water such as treatment with activated carbon (used in the filters in home water purification pitchers) or more advanced technology like ion-exchange resins are very effective. However, they can be too expensive for use in developing countries, especially in rural areas. The need for lower-cost, sustainable alternatives has fostered research on biosorbents.

Thank you Prof. Walid Tawfik for posting this question. I am also eager to know more about "Studies on the use of cilantro for the biosorption of heavy metals in wastewater ". This discovery was presented on September 12 at the 246th annual National Meeting and Exposition of the American Chemical Society (ACS) by scientist Douglas Schauer of Ivy Tech Community College of Indiana, who led a research team to Mexico to find low-cost materials that could filter away industrial pollutants in groundwater.

Thanks for all the above valuable comments. I think in addition to Cilantro,they must use additional filters as well to remove biological traces like cheap activated carbon or so. Do you agree?

It's very interesting and useful.

Could you give more information about this?

Thanks @Peng Zhan for your question. The available information are in the following :

No longer just a flavorful garnish, cilantro has taken center stage in studies that show how the leafy herb might be a new, low-cost solution to purifying drinking water. Popularly used in Mexican and Southeast Asian cuisine, cilantro is being hailed for its potential as a “biosorbent” that can remove lead and other toxic heavy metals from contaminated water.

Typically, water purification relies on advanced technology that uses activated carbon — an approach that is often too expensive for most developing countries, particularly rural areas. Thus, Douglas Schauer, Ph.D. has focused his research on biosorbents, low-cost and sustainable alternatives that rely on natural materials such as microbes and plants. In explaining the appeal of biosorbents, Schauer describes a scenario: “When the filter in a water purification pitcher needs to be changed, they could go outside, gather a handful of cilantro or some other plant, and presto, there’s a new filter ready to purify the water.”

Also known as coriander and Chinese parsley, the plant is easily grown both at home and in the wild, making it readily available for many developing countries afflicted by a contaminated water supply. The key to the plant’s success lies in the architecture of its outer cellular walls that make cilantro ideal for absorbing toxic metals such as lead. Results from small-scale experiments carried out in Mexico have supported Schauer’s research and have even suggested that cilantro was more effective at water purification than conventional methods.

Thanks a lot.

Looks a good idea to expending the range of absorbent. It is worth to do something about it. especially for familiy using

Dr. P.R. Chaudhari, Retd. Scientist, NEERI, Nagpur and AGM, GRC India, Noida

Though Cilantro is having the property of adsorption of heavy metals, it can't be a cheap source of material for drinking water treatment, as it is used as ingredient in food in developing countries. There are lot many waste matter of biological origin like rice husk, which can be used as adsorbents in drinking water treatment. the rice husk is produced in large quantity and generally thrown as waste.

the rice husk is very good idea as well. But can it work alone?

Rice husk (raw as well as thermally activated) was found to be good for removing toxic metals from drinking water by my student in his post graduate desertation for use in rural area. similarly partialy pyrolised rice husk is also found to be suitable for this purpose during literature survey.

My Dear Dr. Pramod Chaudhari,

Okay, I agree with you about rice husk for heavy metal traces removal. The problem is many developing countries have biological water pollution as well. So that, rice husk can't work alone to remove all types of pollution from water. This is my point.

Dear Prof. Walid Tawfik,

You have raised a good question. I want to make it clear theat the natural adsorbants prepared from non-toxic waste biological material (for cost-effectiveness) like rice husk is mostly used for polishing the non-turbid river/lake water to remove toxic compounds and bacteria from it for family utility. For this purpose, a vertical two pot system connected through a filter containing natural adsorbant, in between the pots, shall be constructed. The raw river / lake water is poured in upper pot which will pass throgh the filer into lower pot having tap to draw water. the toxicants and bacteria are filtered out by the adsorbant.

If the water is polluted with biological pollution and turbidity, the natural plant material containing natural coagulents, for ex. Moringa seeds (Moringa oleifera), seeds of Strychnos potatorum or pads of Cactus Opuntia can be used. Powder of the seeds of these former two plants or of pads of Opuntia, when added to water, removes the turbidity as well as bacteria and plankton (due to their coagulent and anti microbial activity) by the process: coagulation - flocculation - sedientation - sand/cloth filtration. This process removes the turbidity and 90-99% bacteria contained in water.

The method (powder of Moringa seeds) for family use is given below:

Prepare the paste by mixing proper dose of moringa powder in small amount of water, then add 250 ml water to it and shake it vigourously in a bottle for one minute, then filter the solution.

[Doses: powder of 1 to 2 seeds per two litre of water for low turbid water (NTU upto 150), powder of one seed per one litre of water for high turbid water (NTU !%) to 250), and powder of 2 seeds per litre of water for highly turbid water.]

Add the coagulent solution to the raw drinking water, stir water rapidly for 1 minute and then slowly for 5-10 minutes.

Let the treated water to settle down for at least 1-2 hours. Then the clean water can be poured off and used for drinking.

This is the best method for family purpose in remote area or in rural area where tap water supply is not available.

It is very interesting task to use natural adsorbents. I think I interest to read your students thesis if available please.

Also, what about if we reach the adsorbent saturation for rice husk, do you think I will converted to be contaminated source ??!!!

Dear Walid Tawfik,

Presently the thesis of my student is not with me but I will get it for you.

the saturation capacity of the adsorbant can be decided after experimentation in terms of volume of water passed through unit weight of adsorbant. After the adsorbant get saturated it can be rejuvenated by chemo-thermal method for few cycles and then can be disposed of suitably.

Okay , i will be waiting your thesis and any related papers as well.

So, It is very important for non-scientist people to know about the saturation capacity of the adsorbent and follow your procedures.

As like any other plant used as a bioabsorbent, Cilantro can also be used as bioabsorbant. It is available every where and usually used in the preparation of foood and known by all. It has better acceptance by people for filtering water.

Thanks for your valuable comment. Please Dr. Prakash Raut did Cilantro price is high for developing countries ? where we can found it?

In India the Cilantro price in comparision with other countries is low as it is used in cooking. Therefore it is a very good option for rural Indians to use this as a cheap source for purification of drinking water.

@ Kia Jackson, see these articles, I hope that helps you.

http://pubs.acs.org/doi/abs/10.1021/jf052858j

http://ir.cftri.com/9589/

http://www.sciencedirect.com/science/article/pii/S0896844606001008

http://www.unido.org/fileadmin/user_media/Publications/Pub_free/A_manual_on_the_essential_oil_industry.pdf#page=202

DEAR WALID, I'M REALLY INTERESTED IN THIS KIND OF METHODS, BECAUSE  I LIVE IN COLOMBIA AND HERE MOST OF THE POPULATION THAT USE WATER FROM BASINS THAT HAVE BEEN EXPOSED BY THE GOLD EXTRACTION INDUSTRY IS IN HIGHLY RISK. BUT I COULDN'T FIND ANYTHING CLEAR THAT SHOWS THE WAY TO IMPLEMENT THE IDEA. DO U HAVE ANY INFO?

THANKS

I see its a 6 yr old thread and hope by now we have some better answers available to the proposed water purification with cilantro. Prof. Walid Tawfik would you kindly share your findings? I saw a few articles on web mentioning about use of cilantro for water purification in Mexico but there are no references to actual studies provided and exploring pubmed wasn’t helpful either .

I came across a study where use of moringa seeds were found effective in cleaning flood water but no such study was found for cilantro. I look forward to hear from you and any other members who may have some better knowledge on the subject by now. Thanking you in anticipation.