Mechanical Biological Treatment (MBT), widely spread in Europe, is a process combined with mechanical separation and biological treatment. This is an alternative technology that can accomplish WtE (Waste-to-Energy) and landfill diversion. Bio-drying, aimed to produce high quality SRF, focused on removing moisture of waste through generated heat when biodegradable organic material is partially degraded by micro-organism. However, most of SRF production facilities in Korea consist of mechanical treatment. In those, 40% of input waste have been generated as residue disposed of in landfill. As a result of physico-chemical characteristic analysis of residue from target facilities, composition of food wastes, papers and plastics ranged 6.7 ~ 18.3%, 9.1 ~ 17.3%, and 5.8 ~ 12.2%, respectively. The moisture content of residue was about 43%, and low heating value was analyzed a range of 1,300 up to 1,900 kcal/kg. Results showed that combustible material having potential to produce SRF is discarded and the amount of biodegradable material such as food waste is still large. Therefore, we assumed it may cause pollution in terms of landfill gas emission and high concentrated leachate generation. In this study, recent trends of Bio-drying is discussed as the alternative technology to solve problems at SRF production facilities in South Korea.
Low temperature is a major factor restrict to growth and limiting productivity of rice crops. We used a cDNA microarray approach to monitor the expression profile of rice (Oryza sativa) under chilling stress and identified 20 chilling inducible genes in previously study. Ten such genes encoding bHLH, metal transporter and, zinc finger protein with unknown functions showed a significant change in expression under various abiotic stresses. Among them, OsCHI1 (Os07g15460), OsCHI2 (Os02g43660), and OsCHI3 (Os01g61160), were selected for further study. They have structural features such as metal-binding signature sequences in their protein sequences, and OsCHI genes were expressed in root of rice seedling and induced in chilling and salt or drought. Expression of OsCHI1, OsCHI3 and OsCHI2 were targeted to membrane and ER when transiently expressed in tobacco cell, respectively. The Arabidopsis (Arabidopsis thaliana) transgenic plants overexpressing showed increased tolerance to salt and drought stress in the seed germination and root elongation than that of wild type. This comprehensive study provides insight into the biological function of OsCHIs, which may be useful in understanding how rice plants adapt to unfavorable environmental conditions.
TILLING (Targeting Induced Local Lesions IN Genomes) is broadly regarded as an excellent methodology for reverse genetics applications. Approximately 15,000 M3 TILLING lines have been developed via the application of gamma-ray irradiation to rice seeds (cv. Donganbyeo), followed by subsequent selections. In an effort to evaluate the genetic diversity of the TILLING population, we have employed the AFLP multiple dominant marker technique. A total of 96 (0.64%) TILLING lines as well as Donganbyeo were selected randomly and their genetic diversity was assessed based on AFLP marker polymorphisms using 5 primer combinations. An average of 100.4 loci in a range of 97 to 106 was detected using these primer combinations, yielding a total of 158 (31.4%) polymorphic loci between Donganbyeo and each of the 96 lines. A broad range of similarity from 80% to 96% with an average of 89.4% between Donganbyeo and each of the 96 lines was also observed, reflecting the genetic diversity of the TILLING population. Approximately 28 polymorphic loci have been cloned and their sequences were BLAST-searched against rice whole genome sequences, resulting in 20 matches to each of the gene bodies including exon, intron, 1 kb upstream and 1 kb downstream regions. Six polymorphic loci evidenced changes in the coding regions of genes as compared to the rice pseudomolecules, 4 loci of which exhibited missense mutations and 2 loci of which exhibited silent mutations. Therefore, the results of our study show that the TILLING rice population should prove to be a useful genetic material pool for functional genomics as well as mutation breeding applications.
TILLING (Targeting Induced local Lesions IN Genomes) is known to be an excellent methodology for reverse genetics approach. About 15,000 M3 TILLING lines have been developed after gamma-ray irradiation to the rice seeds of Donganbye. In order to assess genetic diversity of the TILLING population. we have employed a multiple dominant marker technique, such as AFLP. A total of 96 (0.64%) lines including Dongganbye were randomly selected and their genetic diversity was assessed on the basis of AFLP marker polymorphism by using 5 primer combinations. An average of 100.4 loci with a range of 97 to 106 were detected by using the primer combinations, resulting in 173 (34.6%) polymorphic loci among 96 lines. A broad range of similarities with 80% to 96% was evidenced between Donganbye and each of 96 TILLING lines, reflecting genetic diversity of the TILLING population. About 30 polymorphic loci have been cloned and their sequences have been blasted against rice whole genome sequences. The sequences evidenced highly significant matches to each of genes including exons and introns, upstream sequences and downstream of genes, and intergeneic sequences. Therefore, the TILLING rice population would be valuable genetic sources for rice functional genomics.
Previously, the wheat non-specific lipid transfer proteins (TaLTP), members of a small multigene family, appear to show a complex pattern of expression regulation. For further assessment of expression diversity of the TaLTP genes, we have attempted to evaluate their expression profiles of responses to abiotic stresses via the semi-quantitative RT-PCR method. The expression profiles revealed that the TaLTP genes in group A evidenced highly similar (but not identical) responses against abiotic stresses, whereas much differential expression pattern among genes in each group. The four promoters of TaLTP1, TaLTP7, and TaLTP10 of group A and TaLTP3 of group B were fused to a GUS reporter gene and the recombinant genes were introduced into Arabidopsis. The promoters of TaLTP1, TaLTP7 and TaLTP10 of group A, drove strong but various GUS expression in cotyledons, hypocotyls, epidemic and sub-epidemic cells of young shoots and leaves, floral organs as well as siliques. By contrast, the promoter of TaLTP3 just directed trace expression in cotyledons, young emerged leaves and epidemic cells of flower ovaries. The promoter of TaLTP1 directed the expression in root system whereas the promoters of TaLTP1 and TaLTP10 showed some degree of expression during seed development. The expression diversity of TaLTP genes suggests their multiple physiological functions, evidencing subfunctionalization over evolutionary time.
The objectives of this study have been carried out to investigate the solubilization of municipal sewage sludge by single and dual frequency ultrasonic pretreatment, and the methane production characteristics of pretreated sewage sludge by specific methanogenic activity test for sewage sludge reduction. The waste activated sludge was collected from thickened tank of Suyoung sewage treatment plant in Busan city, and its concentration was adjusted to 1.0% total solids. Ultrasonic frequency was varied 15, 20, 15+20 kHz, and acoustic density was used a maximum 176W/L. The dual frequency ultrasonic pretreatment was found to be more effective than single frequency ultrasonic in the solubilization rate and methane production. The SCODCr/TCODCr rate were 15.2%, 13.9%, 17.0% with single frequency of 15 kHz, 20 kHz, dual frequency of 15+20 kHz, respectively. The application of dual frequency ultrasound for sewage sludge pretreatment can be interest for sewage treatment plants having problems in sludge treatment and disposal.
Comparing predicted PCDF isomer patterns with those obtained from a municipal waste incinerator assessed the role of two-phenol condensation pathways in the formation of PCDFs. Complete PCDF homologue and isomer distributions were obtained from a Fluidized Bed Incinerator (FBI). Two-phenol condensation model, dependent only on the distributions of phenols, was developed to predict the PCDF congeners produced from phenol precursors. R-squared values from linear correlations are presented for the dichlorinated through hexachlorinated isomer distributions between measured and predicted. They range from 0.003 to 0.1 for the dichlorinated through hexachlorinated isomer sets. Agreement between predicted and measured PCDF isomer distributions was very poor for all homologues. Two-phenol condensation pathways are not likely to be the predominant pathways in the formation of PCDF in a FBI. However, dibenzofuran (DF) is likely to be produced from a condensation of two phenols. This work demonstrates the use of PCDF homologue and isomer patterns for testing PCDF formation mechanism from two-phenol condensation pathways in municipal waste incinerators.
This paper analyzes the separation efficiency of vehicles mat residual product, and caloric value, element analysis and heavy metal of separated PE & PVC mat residual product. A results of separation efficiency, fiber fraction of PE & PVC mat residual product was analyzed 71.9% and 18.6%, respectively. Caloric value of PE & PVC mat residual product was analyzed 3,894kcal/kg and 10,203kcal/kg, respectively. A results of element analysis, main component of PVC mat were carbon(33.2%) and oxygen(21.0%), and main component of PE mat fiber were carbon(75.4), hydrogen(11.3%) and oxygen(9.1%). Lead and cadmium concentration of PVC powder was detected 98.9mg/kg and 19.8mg/kg, but Lead and cadmium concentration of fiber was detected 15.7mg/kg and 6.1mg/kg.
This study has been conducted to optimum operating conditions for effective acid fermentation according to OLR(organic loading rate) in the mesophilic and thermophilic acid fermentation process. The results are summarized as follows.
In order to obtain reasonable acid fermentation efficiency in performing acid fermentation of food wastes in thermophilic condition, organic loading rate was required below 20 gVS/L.d. As SCODCr/TKN, SCODCr/T-P of thermophilic acid fermented food wastes in organic loading rate 20 gVS/L.d were 18.9, 73.4 respectively, it was possible to utilize as external carbon source for denitrification in sewage treatment plant after solid-liquid separation as well as co-digestion of fermented food wastes and sewage sludge.
This study has been conducted to investigate biodegradation characteristics and optimum mixing ratio for co-digestion with thermophilic acid-fermented food waste and sewage sludge using batch anaerobic digester. As the basis operating conditions for anaerobic digestion, the reaction temperature was controlled 35±1℃ and stirrer was set 70rpm. Thermophilic acid-fermented food waste and sewage sludge were mixed at the ratio of 10:0, 7:3, 5:5, 3:7, 0:10 and 5;5(food waste : sewage sludge) as the influent substrates. In results of co-digestion according to mixing ratio of thermophilic fermented food wastes and sewage sludge in batch mesophilic anaerobic digestion reactor, 385mL CH4/g VSadded of methane production rate at 1:1 mixing ratio was more than that of any other mixing ratios. Compared with 293mL CH4/g VSadded of methane production rate at 1:1 mixing ratio of food wastes and sewage sludge, pretreatment of food wastes by thermophilic acid fermentation was more effective in co-digestion with sewage sludge.