沼液膜浓缩处理工艺的现状、问题和展望

我国畜禽养殖业在高速发展的同时也带来了严重的畜禽粪便污染问题。厌氧发酵是处理畜禽粪污的有效方式,但是也带来了大量的副产物——沼液。沼液有机物含量较高,碳氮比失调严重,可生化性较差,处置不及时会对环境造成严重污染。膜浓缩技术是沼液资源化处理的有效手段。文章根据国内外研究总结了不同粪污沼液的基本性质;对比了当前常见的沼液膜浓缩技术及其组合工艺的性能,明确了膜污染严重、成本和耗能高、浓缩肥认可度低等限制沼液膜浓缩工艺发展的主要因素;提出了前处理、膜工艺运行参数优化、膜材料改性、膜污染清洗等方式可以提高膜浓缩效率、控制膜污染、延长膜使用寿命。在此基础上,对今后沼液膜浓缩的研究方向进行了展望。

Membrane Process Concentrating Biogas Slurry:Current Situation,Problems and the Prospect

Rapid development of livestock industry has resulted in the large production of livestock manures and thus threatened our environment.Anaerobic digestion has been widely implemented for livestock manure treatment,but it also produces a large amount of byproducts,that is biogas slurry,which has high organic content,imbalanced carbon-nitrogen ratio,poor biodegradability.It will cause serious pollution to the environment if not disposed in time.Membrane technology is an effective means to concentrate biogas slurry for recycle utilization.Based on the researches at home and abroad,this paper summarized the basic properties of different slurry produced by different material,compared the performance of current common biogas slurry membrane concentration processes and their combinations.The main factors limiting the development of membrane process in biogas slurry concentration were identified as serious membrane pollution,high cost,high energy consumption,and low recognition of concentrated slurry fertilizer.The methods of pretreatment,parameter optimization,membrane material modification and membrane fouling cleaning were put forward to improve the efficiency of membrane process,control membrane fouling and prolong the service life of membrane.On this basis,the future research direction of biogas slurry membrane concentration process was prospected.