化学工場の廃液処理によって生ずる活性汚泥の肥料化について

Utilization as Fertilizer of Activated Sludge Produced by the Treatment of Waste Water at a Chemical Factory

Creators Higashi Toshio

Creators Marumoto Takuya

Creators Shindo Haruo

A field experiment of rice was carried out to examine and activated slude, which is produced from the waster water at a chemical factory of ABS resin manufacture, for the heavy metal palution adn the characteristic ecffect of application as fertilizer on rice culture. In this case, it was proved that the pretreatment added to the incoming waster water to eliminater the dissolved heavy metals by a nertralization-precipitation technigue was very effective, and activated sludge produced was harmlees as for heavy metal polution in agricultural application. Because a fair portion of the nitrogen in activated sludge is not mineralized rapidly, higher rate of nitrogen application than the usual optimal rate in the case of chemical fertilizer (0.8kg/a) was requirea on the basal application with the activated sludge to get the best growth and grain yield. And even when the rate was 6.4kg/a, that is 8 times of the usual rate, any disease due to excess nitrogen absorpton was not observed. The basal nitrogen application of 3.2kg/a by the activated sludge gave a continued effect on the growth of rice, making unnecessary the additional application of nitrogen and resulting in higher grain-straw ratio, and fairly more grain yield than the usual application by ammonium sulpate. The 6.4kg/a application also had higher agein yield than usual application, but this treatment retarded the heading and ripening period of rice and lowered the grainstraw ratio, suggesting the upper limit of nitrogen application by the activated sludge. From these results, it would be said that activated sludge is an ideal slow-release nirogen fertilizer for rice culture. (Received June 30,1976)

[ISSN]0513-1715

[NCID]AN00244250