Chemistry Department, University of Allahabad, Allahabad
Retention of Cu++ by compost has been found to be affected by pH and the soluble salts present. An acid compost shows a lower retention but a major portion of the retained ion is easily replaceable whereas the normal sample holds back a greater amount of Cu++ and only a small percentage is exchangeable. The destruction of organic matter, which is responsible to a greater degree for the retention, helps in the release of that form of retained Cu++ by the compost which is not extractable by 0.1N HCl. The maximum amount of Cu++ is extracted by 0.1N HCl. Hydroxy organic acids are able to release appreciable amounts of retained Cu++. Only a fraction of the latter remains in the residual form.
