Pyrite bio-leachate, mine wastewater can sterilize the rice (Oryza sativa L.) seeds and promote the germination.

We developed the way to use pyrite bio-leachate (PBL), the wastewater of bioleaching of refractory gold ore in agriculture. PBL contains high amount of iron and at certain concentration, iron has toxicity on microorganisms. Therefore PBL can be used for rice seed sterilization. Method 1 is soaking rice seeds in 100%, 10%, and 2% PBL for 1, 2, 3, and 4 days (25℃) and drying them. Method 2 is soaking rice seeds in 100%, 10%, and 2% PBL for 30 min, 60 min, and 120 min (25℃), wetting for 2 days under the shade and drying for 5 days. Method 1 with 100%, 10%, and 2% PBL did not sterilize rice seeds completely. Method 2 with 100% and 10% PBL showed the complete sterilization effect and enhanced the germination of rice seeds in any soaking time. Similar results were achieved in seedbed experiments. PBL which has serious potential to pollute the environment can be used for rice seed sterilization. Soaking rice seeds in 100% and 10% PBL for 30 min, 60 min, and 120 min (25℃), wetting for 2 days under the shade and drying them for 5 days, can sterilize the rice seeds completely and enhance the germination.