Martín María Ángeles, González Inmaculada, Serrano Antonio, Siles José Ángel
Department of Inorganic Chemistry and Chemical Engineering, University of Cordoba, Campus Universitario de Rabanales, Edificio Marie Curie (C-3), Ctra. N IV, km 396, 14071 Cordoba, Spain.
Department of Inorganic Chemistry and Chemical Engineering, University of Cordoba, Campus Universitario de Rabanales, Edificio Marie Curie (C-3), Ctra. N IV, km 396, 14071 Cordoba, Spain.
J Environ Manage. 2015 Jan 1;147:330-7. doi: 10.1016/j.jenvman.2014.09.022. Epub 2014 Oct 3.
Sewage sludge is a polluting and hazardous waste generated in wastewater treatment plants with severe management problems. The high content in heavy metal, pathogens and micropolluting compounds limit the implementation of the available management methods. Anaerobic digestion could be an interesting treatment method, but must be improved since the biomethanisation of sewage sludge entails low biodegradability and low methane production. A sonication pre-treatment at lab scale is proposed to increase the organic matter solubilisation of sewage sludge and enhance the biomethanisation yield. Sonication time was optimised by analysing the physicochemical characteristics of sewage sludge (both total and soluble fraction) at different pre-treatment times. The pre-treatment time was fixed at 45 min under the study conditions given that the solubilisation of organic matter did not increase significantly at lower sonication times, whereas the concentration of total nitrogen increased markedly at higher times. The volatile fatty acids generation rate was also evaluated for the pre-treatment conditions. The anaerobic digestion of untreated and pre-treated sewage sludge was subsequently compared and promising results were obtained for loads of 1.0 g VS/L (VS, total volatile solids). The methane yield coefficient increased from 88 to 172 mLSTP/g VS (STP, 0 °C, 1 atm) after the pre-treatment, while biodegradability was found to be around 81% (in VS). Moreover, the allowed organic loading rate and methane production rate observed for the sewage sludge reached values of up to 4.1 kg VS/m(3)·d and 1270 LSTP/m(3)·d, respectively.
污水污泥是污水处理厂产生的一种具有污染性和危险性的废物，存在严重的管理问题。其重金属、病原体和微污染化合物含量高，限制了现有管理方法的实施。厌氧消化可能是一种有趣的处理方法，但由于污水污泥的生物甲烷化具有低生物降解性和低甲烷产量的特点，必须加以改进。本文提出在实验室规模下进行超声预处理，以提高污水污泥的有机物溶解性并提高生物甲烷化产率。通过分析不同预处理时间下污水污泥的物理化学特性（总组分和可溶组分）来优化超声处理时间。在给定的研究条件下，预处理时间固定为45分钟，因为在较低的超声处理时间下有机物溶解性没有显著增加，而在较高的时间下总氮浓度显著增加。还评估了预处理条件下挥发性脂肪酸的生成速率。随后比较了未经处理和预处理的污水污泥的厌氧消化情况，对于1.0 g VS/L（VS，总挥发性固体）的负荷获得了有前景的结果。预处理后甲烷产率系数从88 mLSTP/g VS（STP，0°C，1个大气压）增加到172 mLSTP/g VS，同时发现生物降解性约为81%（以VS计）。此外，观察到的污水污泥允许有机负荷率和甲烷生产率分别达到高达4.1 kg VS/m³·d和1270 LSTP/m³·d的值。
