Wang Yawei, Xiao Qingcong, Zhong Hui, Zheng Xiang, Wei Yuansong
State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; School of Environment and Natural Resources, Renmin University of China, Beijing 100872, China; CSD IDEA (Beijing) Environmental Test& Analysis Co. Ltd., Beijing 100192, China.
J Environ Sci (China). 2016 Jan;39:29-36. doi: 10.1016/j.jes.2015.10.008. Epub 2015 Dec 8.
Microwave (MW) hybrid processes are able to disrupt the flocculent structure of complex waste activated sludge, and help promote the recovery of phosphorus as struvite. In this study, to optimize struvite yield, (1) the characteristics of matter released in MW-hybrid treatments were compared, including MW, MW-acid, MW-alkali, MW-H2O2, and MW-H2O2-alkali. The results showed that selective release of carbon, nitrogen, phosphorus, Ca(2+), and Mg(2+) achieved by sludge pretreatment using MW-hybrid processes. MW-H2O2 is the recommended sludge pretreatment process for phosphorus recovery in the form of struvite. The ratio of Mg(2+):NH4(+)-N:PO4(3-)-P was 1.2:2.9:1 in the supernatant. (2) To clarify the effects of organic matter on struvite recovery, the composition and molecular weight distribution of organic matters were analyzed. Low molecular weight COD was found to facilitate the removal rate of NH4(+)-N and PO4(3)-P via crystallization, and the amorphous struvite crystals (<1kDa) from the filtered solutions had high purity. Therefore, the present study reveals the necessity of taking into consideration the interference effect of high molecular weight organic matters during struvite crystallization from sewage sludge.
微波（MW）混合工艺能够破坏复杂的废弃活性污泥的絮凝结构，并有助于促进磷酸铵镁形式的磷回收。在本研究中，为了优化磷酸铵镁的产量，（1）比较了微波混合处理中释放物质的特性，包括微波处理、微波-酸处理、微波-碱处理、微波-H2O2处理和微波-H2O2-碱处理。结果表明，通过微波混合工艺进行污泥预处理可实现碳、氮、磷、Ca(2+)和Mg(2+)的选择性释放。微波-H2O2是推荐的以磷酸铵镁形式回收磷的污泥预处理工艺。上清液中Mg(2+):NH4(+)-N:PO4(3-)-P的比例为1.2:2.9:1。（2）为了阐明有机物对磷酸铵镁回收的影响，分析了有机物的组成和分子量分布。发现低分子量化学需氧量有助于通过结晶提高NH4(+)-N和PO4(3-)-P的去除率，过滤溶液中无定形的磷酸铵镁晶体（<1kDa）具有高纯度。因此，本研究揭示了在从污水污泥中结晶磷酸铵镁的过程中考虑高分子量有机物干扰效应的必要性。
