Nopharatana Annop, Pullammanappallil Pratap C, Clarke William P
Division of Environmental of Engineering, The University of Queensland, Brisbane, Qld. 4072, Australia.
Waste Manag. 2007;27(5):595-603. doi: 10.1016/j.wasman.2006.04.010. Epub 2006 Jun 22.
A series of batch, slurry anaerobic digestion experiments were performed where the soluble and insoluble fractions, and unwashed MSW were separately digested in a 200l stirred stainless steel vessel at a pH of 7.2 and a temperature of 38 degrees C. It was found that 7% of the total MSW COD was readily soluble, of which 80% was converted to biogas; 50% of the insoluble fraction was solubilised, of this only 80% was converted to biogas. The rate of digesting the insoluble fraction was about four times slower than the rate of digesting the soluble fraction; 48% of the total COD was converted to biogas and 40% of the total nitrogen was converted to ammonia. Soluble and insoluble fractions were broken down simultaneously. The minimum time to convert 95% of the degradable fraction to biogas was 20 days. The lag phase for the degradation of insoluble fraction of MSW can be overcome by acclimatising the culture with the soluble fraction. The rate of digestion and the methane yield was not affected by particle size (within the range of 2-50mm). A dynamic model was developed to describe batch digestion of MSW. The parameters of the model were estimated using data from the separate digestion of soluble and insoluble fractions and validated against data from the digestion of unwashed MSW. Trends in the specific aceticlastic and formate-utilising methanogenic activity were used to estimate initial methanogenic biomass concentration and bacterial death rate coefficient. The kinetics of hydrolysis of insoluble fraction could be adequately described by a Contois equation and the kinetics of acidogenesis, and aceticlastic and hydrogen utilising methanogenesis by Monod equations.
进行了一系列分批式、浆液厌氧消化实验，将可溶部分、不可溶部分以及未清洗的城市固体废弃物分别在一个200升的搅拌不锈钢容器中进行消化，pH值为7.2，温度为38摄氏度。结果发现，城市固体废弃物总化学需氧量（COD）的7%易于溶解，其中80%转化为沼气；不可溶部分的50%被溶解，其中只有80%转化为沼气。消化不可溶部分的速率比消化可溶部分的速率慢约四倍；总COD的48%转化为沼气，总氮的40%转化为氨。可溶部分和不可溶部分同时被分解。将95%的可降解部分转化为沼气的最短时间为20天。通过用可溶部分驯化培养物，可以克服城市固体废弃物不可溶部分降解的滞后期。消化速率和甲烷产量不受颗粒大小（在2 - 50毫米范围内）的影响。开发了一个动态模型来描述城市固体废弃物的分批消化。使用可溶部分和不可溶部分单独消化的数据估计模型参数，并根据未清洗的城市固体废弃物消化的数据进行验证。利用特定的乙酸分解型和利用甲酸型产甲烷活性趋势来估计初始产甲烷生物量浓度和细菌死亡率系数。不可溶部分的水解动力学可以用康托伊斯方程充分描述，产酸动力学以及乙酸分解型和利用氢气型产甲烷动力学可以用莫诺方程描述。
