猪粪堆肥过程保氮固磷及温室气体(N_2O)减排研究

Nutrients Conservation of N & P and Greenhouse Gas Reduction of N_2O Emission During Swine Manure Composting

针对畜禽粪便堆肥过程存在的氮素流失与温室气体(N2O)排放及畜禽粪便堆肥产品土地利用过程的磷素流失等不足,采用强制通风反应器堆肥系统进行小试规模的猪粪堆肥试验,以改性赤泥和改性镁橄榄石为添加剂,考察和比较了这2种改性金属盐添加剂在猪粪堆肥过程对氮磷保存与温室气体(N2O)减排的效果.结果表明,添加改性镁橄榄石(pH=7.0±0.2)堆体(R2)氮损失(以氨气和N2O形式)最少,损失量占TKN的6.38%,而添加改性赤泥(pH=5.0±0.2)堆体(R1)和对照堆体的N损失量分别为TKN的11.07%和14.68%.其中,氨气排放量最少的是添加改性赤泥堆体(R1),N损失为2.13%;N2 O排放量最少的是添加改性镁橄榄石堆体(R2),N2O造成的N损失仅为0.65%.与对照堆体相比,这2种改性金属盐的添加有利于保存氮素和减排温室气体(N2O).此外,堆肥结束后,添加改性金属盐的堆体中水溶性正磷酸盐的含量均低于对照堆体,可减少堆肥产品施用时的磷素流失.

Nitrogen loss and greenhouse gas（N2O） emission occur during animal manure composting,as well as phosphorus loss caused by runoff during land application of animal manure compost.Therefore,the purposes of this study were to simultaneously conserve nutrients of nitrogen phosphorus and reduce N2O emission during animal manure composting using modified salts which are made from industrial solid waste.Experiments of in-vessel swine manure composting at lab-scale were carried out to investigate and compare effects of modified red-mud（MR） and modified forsterite（MF） as additives on nutrients conservation and greenhouse gas（N2 O） reduction.As far as the nitrogen loss calculated on the basis of ammonia and nitrous oxide is concerned,the least nitrogen loss at only 6.38% of TKN occurred in the swine manure composting with MF addition at pH 7.0±0.2,compared with those of MR addition at pH 5.0±0.2 at 11.07% of TKN and the control at 14.68% of TKN,respectively.The best results of ammonia and nitrous oxide mitigation during swine manure composting were the treatments with MR addition and MF addition,which nitrogen losses were at 2.13% of TKN as NH3 and 0.65% of TKN,respectively.These results clearly showed that the modified salt additives from red-mud and forsterite were useful for saving nitrogen and reducing N2O emission.Moreover,the contents of soluble orthophosphate in swine manure compost with the addition of both modified salts were less than that of the control,which is helpful to reduce P loss during land application of swine manure compost.