Abstract Sewage sludge (municipal, or industrial) treatment is still a problem in so far that it is not satisfactorily resolved in terms of cost and final disposal. Two common forms of sludge disposal are possible; the first being direct disposal on land (including agriculture) and the second being incineration (ash production), although neither of these methods are universally applied. Simplifying the issue, direct sludge disposal on land is seldom applied for sanitary and environmental reasons, while incineration is not popular for financial (high costs) reasons. Very often medium and large wastewater treatment plants apply anaerobic digestion for sludge hygiene principles, reducing the amount to be disposed and for biogas (energy) production. With the progress in sewage biological treatment aiming at nutrient removal, primary sludge has been omitted in the working processes and only surplus activated sludge requires handling. Anaerobic digestion of waste activated sludge (WAS) is more difficult due to the presence of microorganisms, the decomposition of which requires a relatively long time for hydrolysis. In order to upgrade the hydrolysis effects, several different pre-treatment processes have already been developed and introduced. The additional pre-treatment processes applied are aimed at residual sludge bulk mass minimization, shortening of the anaerobic digestion process or higher biogas production, and therefore require additional energy. The water-energy-waste Nexus (treads of) of the benefits and operational difficulties, including energy costs are discussed in this paper. The intensity of pre-treatment processes to upgrade the microorganism’s hydrolysis has crucial implications. Here a low intensity pre-treatment process, alkalisation and hydrodynamic disintegration - hybrid process - were presented in order to achieve sufficient effects of WAS anaerobic digestion. A sludge digestion efficiency increase expressed as 45% biogas additional production and 52% of the total or volatile solids reduction has been confirmed.

中文翻译：

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厌氧消化前低强度剩余活性污泥预处理

摘要 污水污泥（市政或工业）处理至今仍是一个问题，在成本和最终处置方面没有得到满意的解决。两种常见的污泥处置形式是可能的；第一种是直接在土地上处置（包括农业），第二种是焚烧（灰生产），尽管这两种方法都没有普遍应用。简化问题，出于卫生和环境原因，很少在土地上直接处理污泥，而由于经济（高成本）原因，焚烧并不受欢迎。大中型污水处理厂经常根据污泥卫生原则应用厌氧消化，减少处理量和沼气（能源）生产。随着以去除养分为目的的污水生物处理的进展，在工作过程中省略了初级污泥，只有多余的活性污泥需要处理。由于微生物的存在，废弃活性污泥（WAS）的厌氧消化更加困难，其分解需要相对较长的水解时间。为了提高水解效果，已经开发并引入了几种不同的预处理工艺。应用的额外预处理过程旨在最大限度地减少残留污泥的体积，缩短厌氧消化过程或提高沼气产量，因此需要额外的能量。本文讨论了水-能源-废物 Nexus (treads of) 的好处和运营困难，包括能源成本。提高微生物水解能力的预处理过程的强度具有重要意义。这里介绍了一种低强度的预处理工艺、碱化和水动力分解 - 混合工艺 - 以实现 WAS 厌氧消化的足够效果。污泥消化效率提高表示为 45% 的沼气额外生产和 52% 的总或挥发性固体减少已被证实。