Studies on removal of phenol sulfonic acid-syntan in aqueous medium using ozonation

<p>The removal of phenol sulfonic acid-syntan (PSAS) in terms of chemical oxygen demand (COD) was studied at different pH, ozone and initial PSAS concentrations and the optimum condition was found to be pH 7, ozone concentration of 5.2 × 10⁻³mmol/L and initial PSAS concentration of 500 mg/L. The increase in BOD₅/COD ratio confirmed the bio-treatability of ozonated PSAS effluent. The excitation–emission matrix intensity and Fourier transmission infra-red spectroscopy confirmed the generation of intermediate by-product during degradation of PSAS. The ozonation of PSAS was found to obey fast regime pseudo-first-order reaction with a rate constant of 3.7 × 10^–9 mol⁻¹ s⁻¹. The mean oxidation state of carbon value between +2 and +3 confirmed that the ozonation of PSAS resulted in partial mineralization.</p

Enhanced Biogas Production from Co-digestion of Intestine Waste from Slaughterhouse and Food Waste

The presence of higher protein and lipids contents of the intestine waste from slaughterhouse affects the anaerobic digestion (AD) process due to volatile fatty acids accumulation and ammonia toxicity. The aim of the present batch reactor study was to evaluate the effect of the mixing ratio on anaerobic co-digestion of intestine waste from the slaughterhouse (IWS) and carbon-rich food waste (FW) to enhance the biogas production and to optimize the C/N ratio for improving the efficiency and better performance of AD. Biogas productions were estimated for various mixing ratios on volatile solid (VS) basis (IWS/FW: 1:1, 1:2, 1:3, 1:4, and 1:5) keeping the inoculum to substrate ratio maintained at 0.5 as per German method VDI 4630. On the basis of the present study, the biogas productions of different mixing ratios at the end of 30th day were found to be on the order of 0.43 (1:2) > 0.39 (1:3) > 0.38 (1:1) > 0.36 (FW) > 0.35 (1:4 and 1:5) > 0.18 (IWS) L/g of VS added. Similarly, the VS removal efficiencies were on the order of 64.02% (1:2) > 61.28% (1:3) > 60.91% (FW) > 60.34% (1:4) 60.21% > (1:2) > 60.15% (1:1) > 47.69% (IWS). Results of the study reveal that the mixing ratio of 1:2 is found to be the suitable mixing ratio which resulted in enhancement of biogas production by 57% and 17% when compared with IWS and FW alone, respectively. The lowest theoretical retention time of 12 days was observed in the mixing ratio of 1:4 with biogas production of 0.28 L/g of VS added while in the mixing ratio of 1:2, the biogas production of 0.35 L/g of VS added was achieved in 13 days

Microfiltration of pretreated sanitary landfill leachate

A laboratory study using a bench scale model of two units operation involving coagulation process with Moringa oleifera seeds extract as a coagulant and filtration process using hollow fibre microfiltration membrane, was adopted to treat Air Hitam Sanitary Landfill leachate in Puchong, Malaysia. The performance of the microfiltration membrane in pretreated sanitary landfill leachate treatment was investigated through a continuous process. The leachate sample was passed through conventional coagulation process before being filtered through a hollow fibre microfiltration membrane of 0.1 µm surface pores. The hollow fibre microfiltration membrane decreased the turbidity, colour, total suspended solids, total dissolved solids and volatile suspended solids in the leachate by 98.30, 90.30, 99.63, 14.71 and 20%, respectively. The results showed that microfiltration is capable of removing high percentage of solids from leachate and might be considered as a polishing stage after on-site biological treatment for sanitary landfill leachate

Pollution reduction and biodegradability index improvement of tannery effluents

Al2 (SO4)3, 18H2O, FeCl3 and Ca (OH)2 were used for the treatment of tannery wastewaters. The influences of pH and coagulant dosages were studied. Conditions were optimised according to the pollutant removal efficiencies, the volume of decanted sludge and the biodegradability index improvement. The results indicate that 6771% of total COD, 76-92% of color and 79-97% of Cr can be removed using the optimum coagulant dosages at the optimum pH range. Al2 (SO4)3, 18H2O and Ca (OH)2 produced better results than FeCl3 in terms of COD, color and Cr removal as well as in terms of biodegradability improvement. Moreover, Al2 (SO4)3, 18H2O and FeCl3 produced the least amount of sludges for a given amounts of COD, color and Cr removed in comparison with Ca (OH)2. Al2 (SO4)3, 18H2O seems to be suitable for yielding high pollutant removals and corresponding low volumes of decanted sludges in addition to improving wastewaters biodegradability index