Interesting question!

heavy metals and metaloids pose serious threat to life and if Cr is present in cow dung or farmyard manure as containment, it is very difficult to remove it. One option is its immobilization tom minimze its availability to plants. But again it will creat another challenge as any strategy adopted for its immobilization may immobilize important plant nutrients in cowdung for which it is specifically applied to soil.

The better solution is to calculate its total contents being added in soil based upon its concentration in the dung and the total quantity of dung to be applied per hectare. If the content is very low and is in permissible limit, then not a big issue. But if the Cr concentration in dung is very high then it should be avoided to apply such manure to field. Other factors to keep in consideration are (soil type, soil pH, nature of crop plants to be grown in the soil and the end use of plants material and main yield components.

Now, I am studying to solve this problem and find some important solution. Activated Carbon may be used. Also Hydroxide precipitation method may be used. There are also some other methods. Here I attach a file for more information.

Dear Mashiur,

Application of SO42- could reduce Cr accumulation in the plant species. Because from your question, it seems you are thinking for how much Cr could be reach in the food crops when this cow-dung used as fertilizer in the fields. A paper has published regarding Cr accumulation in Maize and it has showed application of sulphate could reduce Cr uptake in maize.

You can look this article; Gheju & Balcu (2017). Assisted green remediation of chromium pollution, J. Environ. Management.

Good Luck for your work!

Regards

Arifin

It would be easy to avoid chromium intake by the animal (from the feed) rather than removing chromium from the cow dung. First look for chromium sources to the livestock husbandry