摘要:种养结合是畜禽养殖场粪污处理与利用的一项重要措施。集约化生产条件下,种养结合主要依赖于工程措施来实现,然而工程措施对粪污水理化性状的影响研究不足,限制了粪污水的资源化利用。本文在综述近年来国内外粪污处理各环节理化性状变化研究基础上,重点对固液分离、厌氧发酵、贮存等3个工程环节对粪污理化性状的影响效果进行分析,旨在为规模养殖场粪污资源化利用提供依据。养殖污水经各环节工程措施处理,其颗粒物数量及大小、养分与重金属含量及形态均发生了显著变化。固液分离环节通过机械去除大颗粒物,显著减少粪污水中干物质(DM)总量,降低总氮(TN)和总磷(TP),粪污水中DM、TN、TP的去除效率分别为5.7%~65%、2.7%~49%、2.3%~82%。不同固液分离方法对粪污水中DM、TN、TP的去除效率差异显著,同时还显著地改变粪污水的N:P:K比例,但对Cu、Zn的去除效率较低。厌氧发酵环节主要分解小颗粒物,经厌氧发酵后,粪污水中干物质量大幅度减少,TN、K总量基本不变,但TN组成发生改变,NH4+-N含量显著增加,其占TN的比例达46%~93%;而P、Cu、Zn部分以晶体形式附着于发酵罐内壁,其余部分还会发生液相向固相大量转移的现象。贮存环节由于小颗粒物降解和大颗粒物转化、沉降,使粪污水中干物质总量削减,液相部分TN、NH4+-N、TP、K浓度显著降低。在20~25℃条件下,露天贮存90 d,畜禽粪污沼液TN、TP和K浓度分别降低39%~77%、61%~78%和23%~54%。以上研究对于制定粪污水农田利用工程方案、区域养分综合管理计划具有重要的指导作用。然而,由于我国粪污处理大多采用多级处理工艺措施,而国内外研究侧重于单项工程措施对污水理化性状的影响,现有数据支撑难以提出针对粪污水农田利用的最佳养殖粪污处理方案和组合。粪污水农田利用迫切需要加强两个方面的工作:1)处理工程对粪污水理化性状影响的全过程监测评估;2)基于农田消纳的粪污矿质养分固液相分配定向调控技术研发。
关键词:养殖污水/
固液分离/
厌氧发酵/
贮存/
理化性状
Abstract:The combination of livestock breeding and crops planting is an important strategy for manure utilization and management. Under intensive production, the combination of livestock breeding and crops planting mainly relies on efficient modern engineering measures. However, limited studies have been carried out on the effects of engineering measures on the physic-chemical properties of slurry, which restricts the utilization of slurry as a resource. This paper reviewed recent literatures and analyzed the effects of three engineering measures (manure solid-liquid separation, anaerobic fermentation and storage) on the physic-chemical properties of slurry. The results showed that the number and size of particles, the concentration and morphology of nutrients and heavy metals in slurry changed significantly under intervention of engineering measures. In solid-liquid separation process, almost all large particles in slurry were removed and dry matter (DM), total N (TN) and total P (TP) also significantly reduced, with respective removal efficiencies of 5.7%-65% for DM, 2.7%-49% TN and 2.3%-82% for TP. Removal efficiency of DM, TN and TP as well as the rate N:P:K in slurry significantly varied with solid-liquid separation method. However, few heavy metals such as Cu and Zn were removed in solid-liquid separation process. Small particles decomposition mainly occurred in anaerobic fermentation process, which greatly reduced DM concentration in slurry. After anaerobic fermentation, the total amounts of TN and K changed little, while NH4+-N concentration increased significantly with proportion of TN in the range of 46%-93%. Patches of P, Cu and Zn crystals were attached on the inside walls of the tank, while the remains transferred from liquid to solid in the anaerobic fermentation process. In the storage process, the concentrations of DM, TN, NH4+-N, TP and K significantly decreased in the liquid part of the slurry, due to the decomposition and deposition. After 90 days of storage at 20-25℃, TN, TP and K concentrations in biogas slurry decreased respectively by 39%-77%, 61%-78% and 23%-54%. The study provided relevant guide on designing slurry treatment engineering and formulating comprehensive nutrient management plans in a given region. Since the area of farmland under slurry application is limited in China, livestock manure treatment usually follows multi-stage treatment technology. However, most of the current studies have focused on single engineering measure for the physic-chemical properties of slurry. Thus, it is difficult to put forward the best manure treatment scheme and treatment combination through such data. It was recommended that future works of slurry utilization in farmlands focused on:(1) the monitoring and evaluation of the response of physic-chemical properties of slurry to the entire processes of engineering treatments; (2) the development of directional regulation technology of slurry nutrient between solid and liquid phases for better application of slurry in farmlands.
Key words:Livestock slurry/
Solid-liquid separation/
Anaerobic fermentation/
Storage/
Physical and chemical properties
PDF全文下载地址:
http://www.ecoagri.ac.cn/article/exportPdf?id=a02b187d-be11-4934-a373-0fa02925d597