Biological treatment of palm oil mill effluent by using a downflow hanging sponge reactor

The performance of biological treatment using a downflow hanging sponge reactor as post-treatment of agro-industrial wastewater has been recognized worldwide. However, the effectiveness of the system in treating POME is remain unknown. Therefore, with this background in mind, an anaerobic treatment operated at COD loading rate of 0.4-0.6 kg/m3/day, HRT of 2 hours and input pH of 7.6 was run using a DHS reactor packed with sponge media for the treatment of POME. During the study, the output concentration performances of COD (32-58%), Colour (41-76%), ammoniacal nitrogen (66-92%) and phosphate (54-87%) were recorded. These results indicate comparable performances with the existing biological treatment system. However, it also offered additional credits in-term of fouling and clogging issues, practically as well as lower cost and energy consumption. Thus, it will be great to have a system that is capable to provide a simple technology which is affordable to various industrial scales.

Protection of biomass from snail overgrazing in a trickling filter using sponge media as a biomass carrier: down-flow hanging sponge system

This study investigated down-flow hanging sponge (DHS) technology as a promising trickling filter (TF) using sponge media as a biomass carrier with an emphasis on protection of the biomass against macrofauna overgrazing. A pilot-scale DHS reactor fed with low-strength municipal sewage was operated under ambient temperature conditions for 1 year at a sewage treatment plant in Bangkok, Thailand. The results showed that snails (macrofauna) were present on the surface of the sponge media, but could not enter into it, because the sponge media with smaller pores physically protected the biomass from the snails. As a result, the sponge media maintained a dense biomass, with an average value of 22.3 gVSS/L sponge (58.1 gTSS/L sponge) on day 370. The snails could graze biomass on the surface of the sponge media. The DHS reactor process performance was also successful. The DHS reactor requires neither chemical treatments nor specific operations such as flooding for snail control. Overall, the results of this study indicate that the DHS reactor is able to protect biomass from snail overgrazing.

Drying of Sponge Media Using Swirling Fluidized Bed Dryer

Surface preparation is a process of treating a surface to increase its attraction to coatings and imperative to ensure satisfactory coating can be attained. Conventional techniques of surface preparation usually involve blasting of abrasive material on the surface which usually associated with airborne debris and hazardous contaminant from the process. A relatively new technology in surface preparation is the usage of sponge media as an alternative to the conventional abrasive material. Being soft and elastic, sponge media can reduce airborne emission from surface preparation significantly while being able to be recycled. Unfortunately, the recovery of used sponge media becomes difficult during rainy conditions in which the sponge absorbs water and quickly becomes saturated. Therefore, this paper presents the drying characteristics of sponge media using a swirling fluidized bed dryer (SFBD) for rapid drying to overcome the long, inefficient sun drying as per current practice. Several laboratory scale experiments were carried out to dry water laden of the sponge media in the SFBD. Three bed loadings of 1.7, 2.0 and 2.3 kg were used at drying temperatures of 80°C, 90°C and 100°C. The experimental works revealed the excellent potential of the SFBD in drying the sponge media rapidly. The behaviour of moisture ratio and drying rate against time were discussed. Keywords: Sponge media drying, Swirling Fluidized Bed Dryer (SFBD), Moisture ratio, Drying rate