We have produced three types of biochars from corn stalks, harvest residue of tomato and wheat straw. pH of all three biochars are higher than 9.0. We would like to lower the pH of biochars using phosphoric acid, and at the same time increase the plant available P content of biochar materials.
Thank you very much for your kind considerations in advance.
Si es posible con ácido fosfórico en proporciones de 1 a 2% de de peso
Can u tell me why you select phosphoric acid for acidifying Biochar ?
What is the soil type that u have ?
Thank you
Elif Ada Günal
Its true if you produce biochar at lower temperature say 350-400 it will give you neutral or slight basic pH depending upon the feedstock and pyrolysis conditions. I have seen in some studies, they used repeated distilled water washing to maintain the pH neutral. If you are using biochar for alkali soil then pH should be alkaline but if your experimental requirements needs a biochar with neutral pH then you can go for acidic wash followed by distilled water to remove any excess of acid. You can go through the literature whether phosphoric acid is a suitable choice or not. In my knowledge HCl and sulphuric acid are the most used reagents to neutralise the pH of biochar.