ABSTRACT

Sludge drying is one of the main problems of wastewater treatment plants. It is very important to facilitate the drying process in terms of drying efficiency, time duration, and cost of the processes, so that transportation and dumping of sludge will accordingly be realized effectively. In this study, vacuum assisted thermal drying was studied. Under vacuum conditions, the water content of the sludge was examined easier than at atmospheric pressure in the drying process. For this reason, in this study, time, temperature, and sludge mass surface area on drying efficiency were evaluated under two different pressure levels, such as 30 mbar and 1,000 mbar. To optimize these parameters, the Response Surface Methodology approach was utilized. Results showed that the effect of vacuum condition on sludge drying was remarkable at obtaining at least 65% of solid material ratio in sludge, which is the lowest limit value on landfilling legislation in Turkey. Data obtained from the study shows that, especially at high temperatures, contribution on sludge drying of vacuum condition is more effective in terms of drying time. A smaller sludge surface area is also found more significant on vacuum drying.

Implications: Drying the sludge under low pressure shortens the drying time. It is possible to reach higher solid material ratio under low pressure. Time, temperature, and surface areas of sludge are effective parameters in vacuum drying.

摘要

污泥干燥是污水处理厂的主要问题之一。促进干燥过程在干燥效率、持续时间和过程成本方面非常重要，从而有效地实现污泥的运输和倾倒。在这项研究中，研究了真空辅助热干燥。在真空条件下，在干燥过程中比在大气压下更容易检查污泥的含水量。出于这个原因，在本研究中，时间、温度和污泥质量表面积对干燥效率的影响在两种不同的压力水平下进行了评估，例如 30 毫巴和 1,000 毫巴。为了优化这些参数，使用了响应面方法。结果表明，真空条件对污泥干燥的影响显着，污泥中固体物质比至少达到 65%，这是土耳其垃圾填埋法规的最低限值。研究数据表明，特别是在高温条件下，真空条件对污泥干燥的贡献在干燥时间方面更为有效。还发现较小的污泥表面积对真空干燥更为重要。

影响： 在低压下干燥污泥可缩短干燥时间。可以在低压下达到更高的固料比。污泥的时间、温度和表面积是真空干燥的有效参数。