Browsing by Author "Pillay, V. L."
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- ItemThe applicability of nanofiltration for the treatment and reuse of textile reactive dye effluent(Water Research Commission, 2015) Chollom, M. N.; Rathilal, S.; Pillay, V. L.; Alfa, DorcasThe main aim of the study was to test the feasibility of using nanofiltration (NF) processes for the treatment of reactive dyebath effluents from the textile industry, in order to recover the water and chemicals (salts) for reuse purposes. The study of the reusability of nanofiltered water for dyeing has been given little or no attention. About 30% of reactive dyes remain unfixed on fibres; the unfixed dyes are responsible for the colouration in effluents. Membrane processes were employed to treat reactive dye-bath effluents to recover the salts and water. Investigations were conducted firstly with ultrafiltration (UF) used as a pretreatment for NF. Secondly, evaluations were performed for 2 types of NF membranes (SR90 and NF90), in terms of quality of permeate produced and fluxes achieved for 2 different samples of effluent. The effect of cleaning on membrane performance was assessed. A reusability test was carried out on both permeate samples for dyeing light and dark shade recipes. The use of UF as pre-treatment to NF resulted in rejection of colloidal substances > 90% and a 15% flux improvement. Permeate from NF90 had a conductivity of 76 µS/cm and total organic carbon (TOC) of 20 mg/ℓ, as compared to SR90 which had a conductivity of 8.3 mS/cm and a TOC of 58 mg/ℓ. Light shade from NF90 gave satisfactory results on dyeing, with no colour difference. However a variation in colour was noticed when the medium sample was used to dye the light shade. Both NF permeates gave satisfactory results when used to dye the dark shades. Permeate from NF90 was within the accepted range for reuse, while permeate from SR90 had a higher salt recovery. Chemical cleaning resulted in 80% flux recovery. From the reusability test it was concluded that permeate from NF90 met the reuse criteria for feed water to the dye bath.
- ItemDegradation of synthetic xylan effluent using a membrane bioreactor(Academy of Science for South Africa, 2003) Edward, V. A.; Pillay, V. L.; Swart, P.; Jacobs, E.; Singh, S.We have built a novel membrane bioreactor for the degradation of synthetic xylan effluent. The reactor contains 30 internally skinned polysulphone membranes as an immobilization matrix for xylanase, the degrading agent, and was constructed with stainless steel to withstand high temperatures, as Thermomyces lanuginosus SSBP xylanase has an optimum temperature of 50°C. Overall, 85.1% of the xylanase was immobilized onto the polysulphone membranes by adsorption. Preliminary results showed that the immobilized enzyme was capable of degrading the xylan effluent. Prior to contact with xylanase, there was 0.0 μg ml-1 xylose, 14.2 μg ml-1 xylobiose and 7.2 μg ml-1 xylotriose present in the xylan effluent. After 180 min, the xylose, xylobiose and xylotriose concentrations were 246, 103 and 91 μg ml-1, respectively. Substantial increase in degradation products is promising for the development of a larger-scale bioreactor for effluent treatment.