Decolourization of wood-ethanol stillage using a granular activated carbon packed anaerobic expanded-bed reactor : a thesis presented in partial fulfilment of requirements for the degree of Master of Technology in Biotechnology at Massey University /

The anaerobic treatment (including decolourization) of wood-ethanol stillage from the Forest Research Institute (FRI) wood-hydrolysis pilot plant at Rotorua has been investigated using granular activated carbon (GAC) packed expanded-bed reactors. Specifically, bioregeneration of the GAC in the reactors in terms of organic and colour removal has been considered. Two 7.2 1 anaerobic expanded bed (AEB) reactors were designed and built. Reactor One (R1) was used for the anaerobic digestion of raw wood-ethanol stillage and Reactor Two (R2) for the decolourization of anaerobic lagoon pretreated wood-ethanol stillage. For R1, a desulphated stillage feed (to 500 mg.1-1sulphate) was used. Depending on the organic loading rate (OLR), the additions of nitrogen (N), phosphorus (P) and alkalinity reagent ranged from 240-350 mg.l-1, 80-250 mg.l-1 and 2.5- 4.5 ml 20% w/v NaOH per litre feed respectively. Only N and P feed supplements were used for R2 at 240 and 80 mg.l-1 respectively. The reactors' performance and stability were closely monitored through analyses of volatile fatty acid's, pH, alkalinity, colour, chemical oxygen demand (COD), sulfide, biogas production rate and methane composition, solids concentrations, N and P. After operating R1 for 227 days, it was demonstrated that this system, is superior to the previous systems reported for the treatment of a similar stillage. A non-maximal OLR of 29.0 kg tCOD.m-3.d-1 at 0.85 d hydraulic retention time (HRT) with total and soluble COD (tCOD and sCOD) removals of 74.5 and 83.5% respectively were achieved. Digestion stability was excellent with acetate at 160 mg.l-1, propionate at 490 mg.l-1 and a gas methane composition of 61.0%. The colour loading rate was 4.7 kg chloroplatinate.m-3.d-1 with a 75% colour removal. Higher colour and COD removals may be obtained by operating at a longer HRT (e.g. the percentage colour and sCOD removals were 90.6 and 91.8% respectively at a 2 d HRT). Previously, no significant colour removal for the anaerobic digestion of wood-ethanol stillage has been reported. In this study, only approximately 9% w/v of the chromophoric materials present in the wood-ethanol stillage are particularly recalcitrant to anaerobic degradation. The methane gas yield was near to that predicted by theory (99.7% at 2 d HRT) with a very low sludge yield (2.8% based on 91.8% sCOD removal). Consequently, the AEB reactor had a very low nutrient requirement for effective treatment. In terms of reactor stability, it can accomodate very high hydraulic loading rates (less than 0.85 d) without problems of cell washout. The use of activated carbon medium also provides a toxicity sequesting potential against biological inhibitors present in the wood-ethanol stillage. Continuous bioregeneration of the GAC in R1 has also been demonstrated using sCOD and colour breakthrough curves for GAC adsorption with and without biological activity. Microbial degradation of the chromophoric species has been confirmed using UV-visible spectrophotometric scans. Little methanogenic activity was observed in R2 in its 191 days of operation due to the recalcitrant nature of the anaerobic lagoon pretreated stillage. Only approximately 20% bioregeneration of GAC in terms of colour removal was achieved at a colour loading rate of 1.2 kg chloroplatinate.m-3.d-1. This study has demonstrated that the GAC packed expanded-bed reactor (R1) provides a very effective treatment of wood-ethanol stillage (including decolourization) while recovering a very significant portion (89%) of the stillage energy. Considerable capital and operating cost savings are possible using the AEB system since effective treatment can be achieved in a single step utilizing a relatively small reactor with minimal nutrient, sludge disposal and GAC regeneration or replacement costs. The only disadvantages of the system are the carbon cost, a long start-up period of 5 months and a recycle energy cost to maintain an expanded-bed. It is believed that they can partly be reduced by using a GAC carrier with a smaller particle size. Anaerobic digestion, utilizing a GAC packed expanded-bed reactor, thus represents a cost effective and commercially attractive option for the utilization/disposal of wood-ethanol stillage

A Memory Model for Concept Hierarchy Representation and Commonsense Reasoning

Most associative memory models perform one level mapping between predefined sets of input and output patterns1 and are unable to represent hierarchical knowledge. Complex AI systems allow hierarchical representation of concepts, but generally do not have learning capabilities. In this paper, a memory model is proposed which forms concept hierarchy by learning sample relations between concepts. All concepts are represented in a concept layer. Relations between a concept and its defining lower level concepts, are chunked as cognitive codes represented in a coding layer. By updating memory contents in the concept layer through code firing in the coding layer, the system is able to perform an important class of commonsense reasoning, namely recognition and inheritance

Biodiversity characterization in Malaysia through biology and genetics.

It is often the case that every significant break through in agriculture was preceded by the discovery of some basic biological information. For example, the current widespread practice of planting the tenera type of oil palm in commercial plantations which significantly raised palm oil production was preceded by the discovery of the gene controlling the oil palm fruit shell thickness by Beirnaert and Vanderweyen in 1941 during the course of their research work in the Belgian Congo, Africa (now the Democratic Republic of Congo) (Corley and Tinker, 2003.).Hence, fundamental biological research is important and needs to continue to be supported with adequate and meaningful funding so that Malaysia’s rich biological resources can be well characterized and understood. This will enable them to be utilized economically for the benefit of humankind at their optimal sustainable levels that allow them to continue to thrive in our unique species rich tropical ecosystem. In this regard it is gratifying to note that in the effort to utilize the much touted marker assisted selection (MAS) approach to improve the production of our economic plants and animals, funding had been made available to develop molecular markers for species like oil palm (Singh et al., 2007,2008), Asian river catfish, Mystus nemurus, (Usmani et al., 2003) sea bass, Lates calcarifer, (Chong 2004, Hoh 2008) and the Malaysian giant freshwater prawn, Macrobrachium rosenbergii,(Bhassu et al., 2008) so that high density genetic maps can be generated for them. Such a map is essential before the MAS approach can be effectively applied in the breeding program of any one species (Liu and Cordes, 2004). A Malaysian company, Asiatic Center for Genome Technology (ACGT) is collaborating with the US based Synthetic Genomics Inc. (GSI) on a genome sequencing programme to analyze the entire oil palm genome with a view towards increasing its yield as well as to improve its oil composition to meet the growing market demands (ACGT2006). The Bio Nexus Project and the National Biotechnology Policy launched in May 2005 both aim to explore and utilize in a sustainable manner our rich biodiversity commercially. It is hoped that this policy together with the government’s current aim of revitalizing the nation’s agricultural sector would be accompanied by concrete measures such as the recruitment and retention of competent scientific human resources and increased research and development expenditure in the biological sciences. Then we, the biologists, should respond enthusiastically to our leaders’ clarion call for us to help achieve this noble aim. These actions would, in turn, rekindle interest among young Malaysians in the biological sciences. However, there is the danger that while careers and research in biotechnology, proteomics, genomics and molecular biology are becoming attractive, it must be borne in mind that to manage and utilize our bioresources responsibly, basic knowledge of their taxonomy, physiology, genetics and ecology are just as essential and the good health of our various ecosystems must be maintained. Therefore, biology in Malaysia is a diverse science but with a unity of purpose to enable us to be good trustees of the treasure trove of natural resources that our country has been richly endowed with

Tanda-tanda genetik Orang Asli dan Bangsa-Bangsa Bumiputera Sabah, Sarawak dan Brunei. Kumpulan-kumpulan darah dalam tiga bangsa terbesar di Malaysia dan Singapura: suatu penyusunan data

Suatu senarai data berkenaan dengan kumpulan-kumpulan darah untuk orang-orang Melayu, China dan India (tiga bangsa terbesar di Malaysia dan Singapura) dan juga untuk Orang Asli dari Semenanjung Malaysia dan Bangsa-Bangsa Bumiputera dari Sabah, Sarawak dan Brunei, telah disusun dari sastera sains. Data untuk tanda-tanda genetik biokimia dalam Orang Asli dari Semenanjung Malaysia dan Bangsa-Bangsa Bumiputera dari Sabah, Sarawak dan Brunei pun telah disusun. Taraf adanya data genetik untuk bangsabangsa tersebut dan prospek untuk pengkajian pada masa hadapan telah dibincangkan. Kertas ini menyempurnakan suatu percubaan (dalam dua bahagian) untuk menyusun semua data yang ada pada masa sekarang berkenaan dengan tanda-tanda genetik dalam penduduk-penduduk Malaysia dan Singapura

Automated linear motif discovery from protein interaction network

Master'sMASTER OF SCIENC

Genetic relationship between Kadazans and fifteen other Southeast Asian races

Genetic distance analysis based on five polymorphic biochemical genetic markers was done to determine the genetic distance between Kadazans and fifteen other races living in Southeast Asia. Kadazans were found to he closer to Iban, Paiwan, Visayan, Ifugao, Atyal, Aboriginal ilialays, Land Dayah, Tagalog and Southern Chinese titan they are to Bataks, Senoi, Bunun,malays, Aetas and Southern Indians. Gene frequency comparisons for several new biochemical genetic markers such as soluble glutamate pyruvate transaminase, glyoxalase I and esterase D were made between Kadazans and those few Southeast Asian races 'which had been analysed for these new marhers. In case of those markers in which no data is available for other Southeast Asian races, the Kadazan gene frequencies 'were compared to those of races found elsewhere in the world

The use of a virtual environment in the education of engineering students

This study explores die educational value of using duree-dimension (3D) interactive technology in a virtual reality (VR) environment to augment the learning of engineering students at the polytechnic level in Temasek Polytechnic, Singapore. The virtual environment (VE) consists of a factory floor with different planning tools and machines which students need to interact with to achieve an optimum production rate. Forty second- year engineering students opting for the Computer Integrated Manufacturing (CIM) third year elective were used as subjects. They were separated into two groups of twenty students. The second-year examination results from these two groups of students showed that there was no statistical difference between them, implying that both groups of students had similar initial knowledge. The VR augmentation group used a combined lecture/tutorial format to cover theories of the subject and used die VE as a learning tool to further improve their understanding by solving problems. The traditional instruction group used course notes, tutorial work sheets and teacher-led discussions. The instruments used include a post-test to measure performance, a survey questionnaire consisting of thirty-three 4-point Likert Scale questions, three essay questions, one ranking question and a final concept map type of question. This was followed by an interview to provide a deeper understanding of the use of VR in augmenting the learning process by probing for further details. Results in die post-test indicated that there was no significant difference in the score obtained by students undergoing VR augmentation and the traditional group (p=0.167, d=0.44). However, it was noted that the mean for every question was consistently higher for the VR augmented group. A more detailed analysis showed that for questions relating to problem solving, there was statistical significance (p=0.038, d=0.68) between the scores from the VR augmented group scores and the traditional group. Analysis of inputs from the survey questionnaire and the interview led to a further understanding of the learning aspects of VR, namely the features, learner characteristics, interactive experience, learning experience and the learning itself. This consequently led to an enhanced model of learning in VR

Focus on export potential with Focus Taiwan

Western Australian efforts to increase agricultural and fisheries exports to Asia were given a significant boost in November 1998 with the launch of the Focus Taiwan Project. Dr Soon Chye Tan reports on the aims of Focus Taiwan and how the project is already influencing Western Australian export opportunities