The discharge of textile wastewater containing dye in the environment is varying for both toxicology and esthetical reasons as dyes impede light penetration, damage the quality of the receiving streams. Upflow anaerobic sludge blanket reactor with anaerobic digester sludge treating starch wastewater has been used to investigate the removal efficiency of chemical oxygen demand (COD) and colour of textile dye wastewater. In this study, the starch and textile dye wastewater was mixed at 70 and 30%, respectively, and the experiments were carried out with recycle of treated wastewater at different percentage as 10, 20, 30 and 40. Maximum removal of COD and colour was 96% and 93.3%, respectively, at 30% recycle. At various OLR and HRT, the maximum removal of COD, colour was 95.9%, 93% at 6.81 kg COD/m 3 d and 96%, 93% with 24 h of HRT. The maximum production of biogas at 24 h of HRT with 30% recycle was about 355 l/d. The Volatile fatty acid/Alkalinity ratio of methanogenic reactor was found to be 0.049-0.053. The result provided evidence, the starch and dye wastewater have wide variation in their characteristics was treated on combination, this new technology supports the effective utilization of starch waste in destruction of dye.

16S rRNA: 16S ribosomal RNA; COD: Chemical oxygen demand; DNA: Deoxyribonucleic acid; dS/m: deciSiemens per metre; g/L: gram per litre; HRT: Hydraulic retention time; mg/L: milligram per litre; OLR: Organic loading rate; PCR: Polymerase chain reaction; RNA: Ribonucleic acid; UASB: Upflow anaerobic sludge blanket; VFA: Volatile fatty acid; VSS: Volatile suspended solid.

Biological degradation of 2-chlorophenol (2-CP) was investigated in an anaerobic batch reactor using starch water as co-substrate. Experiments were carried out with various mixing ratios of synthetic starch water and 2-CP viz. 90:10, 80:20, 70:30, 60:40, 50:50 and the extent of degradation were quantified. High COD removal efficiency of 97.1% and 97.5% of 2-CP removal was achieved at mixing ratio of 80:20. The bio-kinetic parameters such as maximum specific growth rate (µmax), half velocity constant (Ks) and inhibition constant (Ki) were determined for a mixed anaerobic consortia by both Monod and Haldane models. The growth kinetics represented by Haldane model is found to be very suitable than the Monod model for degrading the combined wastewater of 2-CP and starch The maximum specific growth rate (µmax, h-1), substrate half saturation coefficient (Ks, mg/L) and the substrate inhibitory coefficient (Ki, mg/L) for Haldane model are in the range of 0.00005-0.02, 51.3-774 and 146.6-2272.7 .The correlation coefficient R2 was found to be 0.99 for Haldane model and 0.89 for Monod model.

Chlorophenol compounds are environmental pollutants that are both anthropogenic and xenobiotics. Some of these chemicals are carcinogenic and toxic to a number biochemical processes. The present research aims at 2-CP degradation in a UASB reactor with starch water as cosubstrate. Synthetic 2-CP and starch water were given as feed to UASB reactor at an HRT of 24 h. The performance of the reactor was remarkably stable and efficient during 2-CP additions at a range of 5-800 mgL -1 . The reduction of 2-CP and COD was found to be 100-67.9 and 98.1-59.3% respectively. The optimum 2-CP and COD removal efficiencies were 97.5 and 90.4%. The VFA concentrations of the reactor were lesser than 250 mgL -1 . The biogas production at 600 mgL -1 of 2-CP was 20 Ld -1 .