梁康强1，朱民1，林秀军1，孙宇2
(1．北京市环境保护科学研究院，北京100037；2．中国环境科学研究院，北京100012)

摘要：采用反渗透膜工艺浓缩沼液，针对沼液悬浮物颗粒过大浓度过高、钙镁离子超标等问题，采取预处理手段对反渗透膜片进行保护，以保证系统的产水量和运行成本达到最佳。结果表明，在自然沉淀、混凝、离心过滤和滤袋过滤四种去除悬浮物工艺中，自然沉淀和离心过滤效果最佳，其出水悬浮物粒径均在10以下。通过自然淀时间优化，自然沉淀最佳时问为1天，既能保证出水效果，又能节省沉淀池容和投资。对于钙镁离子和硫酸根离子结垢，采用反渗透膜厂家提供配方，并智能化添加阻垢剂，长期运行结果证明，防结垢效果较好，平均碱洗周期为120 h，酸洗周期为360 h。
    关键词：预处理；沼液；反渗透；膜浓缩
    中图分类号：X506；$216．4 文献标志码：A 文章编号：1000一1166(2013)02—0008—04

Pretreatment of Biogas Slurry for Its Concentrating by Reverse Osmosis／LIANG Kang-qian91，ZHU Minl，LIN Xiu-junl，SUN-Yu2／(I．Beijing Municipal Research Academy of Environmental Protection，Beijing 100037，China；2．Chinese Research Academy of Environmental Sciences，Beijing 100012，China)

Abstract：There ale some problems in biogas slurry concentrating by reverse osmosis method，which related to the suspended solid，calcium and magnesium ions in biogas slurry，for the diameter of suspend solid is too long and the concentration is too high，and both calcium and magnesium contents were exceed the standard．Accordingly，the pretreatment process protecting the reverse osmosis membrane is put forward in this paper SO as to ensure the maximunl water production and least operation cost．The results showed that，among the methods of natural precipitation，coagulation，centrifugal filter and bag filter pmcesse，the natural sedimentation and centrifugal filtration had the best effectiveness，for the particle size of SUS．pended solids in pretreated biogas slurry was smal]er than 10 Ixm．Through optimization，the best precipitation period was 1 day．In this way，not only the water production could be guaranteed，but also sedimentation tank volume could be smaller and investment cost could be lower．As for the calcium，magnesium and sulfate ion scaling，formula was provided by osmosis membrane manufacturers and intelligent scaling inhibitor Was added．The long-term operation results showed well anti· scaling performance．The average 8lkali—wash cycle was 120h and pickling cycle was 360 h．
    Key words：pretreatment；biogas slurry；reverse osmosis；concentration；membrane method

1前言
    针对沼气工程中沼液产量大、处理成本高、储存运输困难和营养物质含量偏低等问题，提出采用高耐污反渗透技术对沼液进行浓缩。膜分离是在分子范围内进行分离，同时以压力为推动力，装置简单，操作容易，控制、维修方便。沼液浓缩的要求和膜分离的特点使得膜分离工艺成为沼液浓缩的不二选择。