Hydrogen as a quick indicator of organic shock loading in UASB

This study investigates the influence of organic shock loading on H-2 production in an upflow anaerobic sludge bed (UASB) reactor. An esterification wastewater produced from a polyethylene terephthalate (PET) manufacturing plant was applied; the major organic pollutants are ethylene glycol and acetaldehyde. Experiments of two influent modes were performed here: a continuous-flow mode with a step input of shock loading and a batch mode with a pulse input of shock loading. Results of the continuous-now experiments indicate that biogas production parameters such as H-2 concentration and biogas production rate are more sensitive than water quality parameters such as pH, ORP, COD and TOC. In particular, H-2 increasing by 140% within I hour, is a very important index upon the organic shock loading. It changes from 120 ppm to over 600 ppm as the organic loading rate increases from 4.4 to 13.2 kgCOD/m(3) day through 4 hours of shock loading. Experiments of the batch shock loading with different pulse dosages of ethylene glycol, acetaldehyde and the raw wastewater were also investigated. The amount of H-2 production increased in proportion to an increase of organic load. Furthermore, the sequence of H-2 production among the three types of shock loading is acetaldehyde> ethylene glycol> raw wastewater. To sum up, Hp shows a faster response rate than the other parameters. Therefore, H-2, can be adopted as an important parameter for organic shock loading in UASB.