Colour removal and its mechanisms in textile wastewater treatment by UASB reactor system with anaerobic granular sludge

Textile wastewaters generated from different stages of textile processing contain various toxicants orpollutants that are seriously harmful to natural aquatic environment when released without propertreatment. Although there are different methods, which can be adopted for the treatment of textilewastewater. biological approaches are considered as environmentally friendly, low cost and effectivemethods over other physico-chemical methods. In the present study, simulated textile wastewater(STW) prepared by mixing of three popular acid dyes (Acid blue 204, Acid red 131 and Acid yellow79) in synthetic wastewater was studied for the decolourization and removal of degradable organic inthe laboratory scale Upflow Anaerobic Sludge Blanket Reactor system with anaerobic granular sludgefor about five months at different organic and dye loading rates. The colour removal mechanismsunder .maerobic treatment were also examined since microbial colour removal occurs basically in twoways namely biological degradation, which is more important in textile wastewater treatment, andadsorption of dye molecules onto microbial biomass. Chemical oxygen demand (COD) removal ofacid red 131 (AR 131) containing STW was about 80% at 300 mg/l dye concentration and it was over89% in acid yellow 79 (AY79) dye containing STW under studied conditions. Although acid blue 204(AB204) showed a little inhibition over rnethanogenic consortia, about 93% of COD removal wasobserved at 100 mg/l dye concentration. Colour removal of AR 131 dye containing STW was 95% and.it was credited to biodegradation. Treatment of STW prepared using AY79 showed 95% colourremoval owing to biodegradation while AB204 was quite resistant to biodegradation by anaerobicrn icroorgan isms. Observed colour removal was merely due to the adsorption of dyes onto microbialgranules. Even though a little accumulation of volatile fatty acid (YFA) was observed in increaseddye concentrations, the detected values ofYFA, alkalinity and pH showed that those values were inthe range of desirable limits of anaerobic process. It seems that AR 131 and AY79 can be decolourizedalmost completely by UASB reactor system while AB204 cannot be decolourised since all colourremoval attributed to adsorption of dye onto microbial granules. It can be concluded that anaerobictechnology can be used for the treatment of textile wastewater containing different dyes as an alternativemethod over other methods. However, further study ofUASB reactor for the treatment of real textilewastewater is suggested to find out matrix effect of other chemicals present in real textile wastewaterbefore application to the real world situations

An Integrated Strategy to Study Muscle Development and Myofilament Structure in Caenorhabditis elegans

A crucial step in the development of muscle cells in all metazoan animals is the assembly and anchorage of the sarcomere, the essential repeat unit responsible for muscle contraction. In Caenorhabditis elegans, many of the critical proteins involved in this process have been uncovered through mutational screens focusing on uncoordinated movement and embryonic arrest phenotypes. We propose that additional sarcomeric proteins exist for which there is a less severe, or entirely different, mutant phenotype produced in their absence. We have used Serial Analysis of Gene Expression (SAGE) to generate a comprehensive profile of late embryonic muscle gene expression. We generated two replicate long SAGE libraries for sorted embryonic muscle cells, identifying 7,974 protein-coding genes. A refined list of 3,577 genes expressed in muscle cells was compiled from the overlap between our SAGE data and available microarray data. Using the genes in our refined list, we have performed two separate RNA interference (RNAi) screens to identify novel genes that play a role in sarcomere assembly and/or maintenance in either embryonic or adult muscle. To identify muscle defects in embryos, we screened specifically for the Pat embryonic arrest phenotype. To visualize muscle defects in adult animals, we fed dsRNA to worms producing a GFP-tagged myosin protein, thus allowing us to analyze their myofilament organization under gene knockdown conditions using fluorescence microscopy. By eliminating or severely reducing the expression of 3,300 genes using RNAi, we identified 122 genes necessary for proper myofilament organization, 108 of which are genes without a previously characterized role in muscle. Many of the genes affecting sarcomere integrity have human homologs for which little or nothing is known