a Department of Civil Engineering , University of British Columbia , Vancouver , British Columbia , Canada.
J Environ Sci Health B. 2014;49(7):532-9. doi: 10.1080/03601234.2014.896681.
Dairy manure, acidified using organic acids (acetic, oxalic, and citric acid) were treated with microwave enhanced advanced oxidation process (MW/H2O2-AOP). The effect of a mixture of oxalic acid and commonly used mineral acids (sulfuric and hydrochloric acid) on MW/H2O2-AOP was also examined. Substantial amounts of phosphorus were released under MW/H2O2-AOP, regardless of organic acid or mineral acid used. All three organic acids were good acidifying reagents; however, only oxalic acid could remove free calcium ion in the solution, and improve settleability of dairy manure. The MW/H2O2-AOP and calcium removal process could be combined into a single-stage process, which could release phosphate, solubilize solids and remove calcium from dairy manure at the same time. A mixture of oxalic acid and mineral acid produced the maximum volume of clear supernatant and had an ideal molar ratio of calcium to magnesium for effective struvite (magnesium ammonium phosphate) crystallization process. A single-stage MW/H2O2-AOP would simplify the process and reduce mineral acid consumption compared to a two-stage operation. The results of a pilot scale study demonstrate that MW/H2O2-AOP is effective in treating manure and recovering resource from dairy farms.
使用有机酸（乙酸、草酸和柠檬酸）酸化的牛粪经过微波强化高级氧化工艺（MW/H2O2-AOP）处理。还研究了草酸和常用矿物酸（硫酸和盐酸）混合物对 MW/H2O2-AOP 的影响。无论使用有机酸还是矿物酸，MW/H2O2-AOP 都会释放大量的磷。三种有机酸都是很好的酸化试剂；然而，只有草酸可以去除溶液中的游离钙离子，并提高牛粪的沉降性能。MW/H2O2-AOP 和钙去除过程可以组合成一个单级工艺，同时可以从牛粪中释放磷酸盐、溶解固体并去除钙。草酸和矿物酸的混合物产生了最大量的澄清上清液，并且具有用于有效鸟粪石（磷酸铵镁）结晶过程的理想钙与镁摩尔比。与两级操作相比，单级 MW/H2O2-AOP 可简化工艺并减少矿物酸的消耗。中试规模研究的结果表明，MW/H2O2-AOP 可有效处理粪便并从奶牛场回收资源。
