Research on recovery of nitrogen released in composting process

在堆肥过程中，氨气在良好的消化期释放。另一方面，由于消化速率高于供氧速率，在堆肥初期容易产生低脂肪酸。排放的氨气不仅造成环境污染，而且造成氮资源的损失。如果能够回收氨或将其吹入产生脂肪酸的堆肥中，则可以很好地解决1)环境污染问题，2)减少堆肥中氮的损失，3)通过ph中和提高消化速度。通过堆肥本身作为吸附介质回收释放的氨气的研究已经取得了基础知识。研究结果如下：1)堆肥过程中释放氨气造成的氮损失达到原料中氮的50%。2)堆肥吸附氨量与水干料比和酸浓度均成线性关系。3)堆肥填料塔可去除氨气量与气体浓度无关。4)由于堆肥液相铵浓度远高于最佳范围，即使控制在最佳pH和温度范围内，吸附的氨在第一消化期也很难硝化。

In composting process, ammonia gas is released in well digesting period. On the other hand, low fatty acids tends to generate in initial period of composting, because of higher digestion rate than oxygen supply rate.The released ammonia gas causes not only environmental polution but also lossof nitrogen as a resource. If it is abailable to recover ammonia or to blow it into the compost generating fatty acids, it well 1) solve environmental pollution problem, 2) minize the nitrogen loss in compost and 3) promote the digestion rate by neutralizing in pH.The research has conducted to get fundamental knowledge to recover the released ammonia gas by compost itself as adsorption media.The results are as follows;1) The loss of nitrogen by releasing of ammonia gas in composting process reaches 50% of nitrogen in raw material.2) Adsorbable ammonia quantity by compost is linear both to water/dry-solid ratio and acid concentration.3) The removable ammonia gas quantity by compost-packed-tower is independent from gas concentration.4) The adsorbed ammonia is hardly nitrified in first digestion period even if it is controlled in optimal pH and temperature range, because the ammonium concentration in liquid phase of the compost is much higher than optimal range.