기체투과막 기술을 이용하여 가축분뇨 폐기물 등으로부터 암모니아성 질소를 효과적으로 회수할 수 있다. 이는 폐기물 내 암모니아 기체가 폐기물에 함침된 기체투과막의 미세공극을 투과하여 막반대편에 도달하게 된다. 투과된 암모니아 기체분자는 막 반대편에 존재하는 용액 내 황산 등 산에 의해 포획 및 회수된다. 막 유입부 내 암모니아성 질소 제거 효과를 높이기 위해서는 우선 유입 폐기물 내 pH를 높게 유지해야 하는데 pH 상승에 필요한 염기성 약품 투입비용이 문제가 될 수 있다. 기존 연구에서는 보다 저렴한 소석회 투입하거나 폭기 혹은 질산화억제를 통해 높은 pH를 효과적으로 유지시키는 방 안이 거론되고 있다. 한편 암모니아성 질소 회수에 쓰이는 기체투과막의 재질은 적절한 내열성이나 내화학성 이외에도 소수 성을 띈다는 특징이 있으며 이를 통해 막기공을 통해 암모니아 기체를 선택적으로 투과시킬 수 있다. 향후 연구에서는 다양 한 성상을 가진 현장 폐기물을 이용하여 실증 Test를 수행하고 이를 기반으로 최적 설계/운전 조건 규명 및 경제성 제고 방안 을 수립하여야 한다.

This paper presents the applicability of natural zeolite (Clinoptilolite) for recovery of ammonium nitrogen from high-strength wastewater stream. Isotherm experiments showed the ammonium exchange Clinoptilolite followed Freundlich isotherm and its maximum exchange capacity was 18.13 mg NH4+-N/g zeolite. The X-ray photoelectron spectroscopy (XPS) analysis indicated that a significant amount of nitrogen was adsorbed to the Clinoptilolite. Optimal flowrate for recovery of high concentration ammonium nitrogen was determined at 16 BV/d (=19.2 L/min) throughout the lab-scale column studies operated under various flowrate conditions. This study also provided a method to determine the recovery rate of final product of nitrogen fertilizer based on the model application to the lab-scale continuous data.

유지(由地)의 경사도(傾斜度)(10˚, 20˚, 30˚) 및 3 요소(要素)(N-P2O5-K2O)의 시용수준(施用水準)(0-0-0, 14-10-10, 28-25-25, 42-40-40kg/10a)이 겉뿌림 산지초지(山地草地)(orchardgrass, tall fescue, redtop, ladino clover 혼파(混播)의 조성(造成), 생산성(生産性), 식생(植生) 및 목초품질등(牧草品質等)에 미

This study evaluated the feasibility of recovering and recycling nitrogen (N) and phosphorus (P) from livestock excreta as struvite (MgNH4PO4·6H2O) in South Korea. Our experimental results showed that struvite precipitation was a very effective way to recover N and P from livestock excreta. Moreover, our study demonstrated that struvite precipitates from livestock excreta (SPL) contain higher concentrations of N, P, and magnesium (Mg) as compared to compost and liquid manure from livestock excreta. In addition, although SPL contain high concentrations of copper (Cu) and zinc (Zn), they meet the fertilizer criteria for concentrations of heavy metals. In South Korea, SPL cannot currently be used as a fertilizer due to legal constraints. Legal permission for SPL use would offer greater choice in livestock excreta management. In conclusion, recovery and recycling of N and P from livestock excreta as struvite can be an effective tool for managing nutrients in livestock excreta.

This study assessed the fertilizing value of struvite deposit recovered from swine wastewater in cultivating Chinese cabbage. Struvite deposit was compared with commercial fertilizers: complex, organic and compost to evaluate the fertilizing effect of struvite deposit. Laboratory pot test obviously presented that the struvite deposit more facilitated the growth of Chinese cabbage than organic and compost fertilizers even though complex fertilizer was the most effective in growing Chinese cabbage. It was revealed that the growth rate of Chinese cabbage was simultaneously controlled by phosphorus (P) and potassium (K). Also, the nutrients such as nitrogen (N), P, K, calcium (Ca) and magnesium (Mg) were abundantly observed in the vegetable tissue of struvite pot. Specifically, P was the most abundant component in the vegetable tissue of struvite pot. Meanwhile, the utilization of struvite as a fertilizer led to the lower accumulation of chromium (Cr6+) than other pots, except for compost fertilizer pots, and no detection of cadmium (Cd), arsenic (As) and nickel (Ni) in the Chinese cabbage. The experimental results proved that the optimum struvite dosage for the cultivation of Chinese cabbage was 2.0 g struvite/kg soil. On the basis of these findings, it was concluded that the struvite deposits recovered from swine wastewater were effective as a multi-nutrient fertilizer for Chinese cabbage cultivation.

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.