Fluorine (F) recovery from wet process phosphoric acid (WPA) is essential for sustainable resource utilization and environmental protection. This work systematically investigates the F recovery mechanism by air stripping from three simulated systems: H3PO4- H2SiF6-H2O, H3PO4- HF-H2O, H3PO4- H2SiF6-HF-Al3+-H2O, and from two industrial systems: WPA and WPA-Al3+ under different stripping temperatures (60–110 ℃) and stripping times (0–120 min). The influence on the existence form of F, the content of Al3+ cations and the addition of active silica on the F removal rate in the phosphoric acid solution is studied by analyzing the changes in the contents of F, P and Si. The results indicate that the F in the form of H2SiF6 is more easily released from the phosphoric acid solution than that in the form of HF. While, the release of F is inhibited in the presence of the Al3+ in the solution due to the formation of Al-F complexes that are characterized by 19F NMR, 31Si NMR and FTIR techniques. Interestingly, the addition of active silica can promote the conversion of HF to H2SiF6 in the solution and significantly improve the release rate of F. The researching results can provide an important guidance for industrial practice of WPA.

가축분뇨의 퇴/액비를 통한 자원화는 경종농가에서의 화학비료 사용으로 인한 양분집적 문제가 발생하고 있다. 따라서 가축분뇨 및 공동자원화시설과 연계한 질소 회수 기술 개발 및 적용을 통해 지역별 양분관리 기술 제공 및 양분총량제에 대응한 가축분뇨 자원화 기술 제공이 필요한 실정이다. 이에 본 연구에서는 가축분뇨 내에 존재하는 암모니아를 50% 회수함으로써 경제성을 증가 시키고 공정에서 발생하는 악취 문제를 2차적으로 해결함으로써 부가적인 효율을 증대시킬 수 있다. 또한 회수된 암모니아를 이용하여 암모니아수, 황산암모늄 등 암모니아화합물을 제조하여 제품화함으로써 부가가치를 창출할 수 있어 시설 투자비와 운전비 대비 부가가치 창출을 기대할 수 있다. 이에 실험실 규모에서의 50% 암모니아 회수 최적 조건과 회수된 암모니아를 이용하여 암모니아화합물 생성 최적 조건을 도출하였다.

Air stripping of ammonia is a widely used process for the pretreatment of wastewater. Lab scale experiments were removal of 50% to air stripping from livestock excretions. The effects of air to liquid flow ratio and pH were investigated using wastewater with a range of Total suspended solid concentration and pH values. Four sets of air stripping experiments were carried out using two identical 0.5 L and 1 L reactor made of pyrex. At a temperatures of 20℃, pH 11 and air flow rate of 10 L/min, aeration 180min to achieve 90% removal efficiency. However, at a pH 9~9.5 there was 50% removal efficiency. The results showed that an influent with a low pH required a longer period of time to achieve the same treatment efficiency.

The amount of nutrients entering the soil annually about 100 million tonnes. Among the 100 million tons of nutrients is chemical fertilizers 600,000 tons with manure compost/liquid fertilizer 400,000tons. Fifty percent of nutrients is sprayed to soil but the crop is not used. So building up nutrients in the soil is released into the water together. There is no system that can maintain nutrient balance of the country. Chemical fertilizers and manure compost manure is used on an ongoing basis. Rivers, oceans, lakes, and reservoirs become serious problems of eutrophication. Nitrogen and phosphorus is the cause of eutrophication. As the excessive accumulation of water discharged to the environment, resulting in algae and red tides. The government responded by introducing the amount of total nutrient system in 2008. So the amount of nutrient that can be sprayed on the soil was picked reduced. For the reason, the farmers is became the handling of manure seriously. Since 2012, the manure is that speculation was banned in the ocean. Processing method and system response measures on land was needed. In this study were investigated for reuse and to remove the ammonium nitrogen contained less than 80 % of the total nitrogen with the Air stripping technique.