NOPR Collection:

Decolourization of dye wastewater by microbial methods- A review

2018-09-05T09:33:12Z

Title: Decolourization of dye wastewater by microbial methods- A review Authors: Parmar, Neha D; Shukla, Sanjeev R Abstract: Waste water originating from textile processing and dyestuff manufacturing industries contain varying amounts of dyes, metals/metalloids, salts and organic pollutants out of which dyes are the visible toxic contaminants. Presence of dyes in water bodies causes several problems including decreased photosynthesis and higher BOD and COD load, apart from their displeasing appearance. Dyestuffs are organic molecules, which may be toxic or mutagenic. In the last few years, environmental legislation about the presence of colour in discharges, coupled with the increasing cost of water for the industrial sector, has made the treatment and reuse of dyeing wastewaters increasingly important to the industry. A variety of approaches are available for treatment, out of which the biological treatment is the genuinely ecofriendly and cost effective method. The decolourization efficiencies of different biological methods are discussed in this review along with the detailed discussion on bacterial treatment and their relative merits and drawbacks. Page(s): 315-323

Ultrasound-assisted removal of brilliant green from aqueous solution using banana and jackfruit peels

2018-09-05T09:31:05Z

Title: Ultrasound-assisted removal of brilliant green from aqueous solution using banana and jackfruit peels Authors: Pathak, Pranav D; Singh, Paradeep; Mandavgane, Sachin A Abstract: The potential use of banana (BP) and jackfruit peel (JFP) as eco-friendly and low-cost adsorbents for removal of brilliant green (BG) dye from waste water in the presence of ultrasonic field has been studied. Batch process has been used for adsorption kinetic, equilibrium, and thermodynamic studies. Results show that the amount of BG adsorbed and the rate of adsorption increased in presence of ultrasonic field. The adsorption of BG onto BP and JFP is fast (equilibrium time for the adsorption is about 25 min) and follows the pseudo-second-order kinetic model. The Langmuir isotherm shows the best fit for the adsorption of BG onto BP, where as both Langmuir and Freundlich adsorption isotherms show best fit for the adsorption of BG onto JFP (R²=0.99). The maximum adsorption capacities calculated using the Langmuir isotherm are 21.74 and 31.25 mg/g at 313 K for BP and JFP, respectively. The ΔG values are negative at all operating temperatures, confirming that the adsorption of BG is spontaneous and thermodynamically favorable. The positive value of ΔS suggests the increased randomness at the adsorbate–adsorbent interface. Overall, our study suggests that BP and JFP can be used as an ecofriendly and low-cost agro-material for removal of BG dye from aqueous solutions. Page(s): 324-335

Production and characterization of pyrolysis oil using waste polyethylene in a semi batch reactor

2018-09-05T09:28:26Z

Title: Production and characterization of pyrolysis oil using waste polyethylene in a semi batch reactor Authors: Gaurh, Pramendra; Pramanik, Hiralal Abstract: Plastic waste, polyethylene has been used as a feed stock for the production of valuable hydrocarbons via thermal pyrolysis. The thermal pyrolysis of waste polyethylene has been investigated in a specially designed semi batch reactor with L/D ratio of 1.2. Polyethylene sample of 50 g is used as feed using different reaction temperatures from 500-800°C. The reaction time of 30 min is maintained irrespective of variation in other experimental conditions. The pyrolysis oil are characterized using API gravity, flash and fire point, calorific value, carbon residue, proximate analysis, ASTM distillation and GC-FID, The maximum liquid yield of 72.6% is obtained at a temperature of 800°C, whereas the liquid yield was 61.5% at the temperature of 500°C. Though the liquid yield is maximum at 800°C, the pyrolysis oil solidifies at 32°C, which indicates higher paraffins are more. The solid char produced was minimum (9.4 wt %) at 800°C and it was maximum (20.44 wt. %) at 500°C. There is minor change in gaseous hydrocarbon yield irrespective of pyrolysis temperature. The liquid yield obtained at 700°C exhibit the properties similar to commercial diesel with boiling point range 270-320°C i.e., similar to beyond 50% distillate recovery as tested in ASTM D86. GC-FID tests of pyrolysis oil (700°C) gives comparable GC characteristics of commercial diesel. Page(s): 336-344

Removal of nitrites from waste waters using adsorbents derived from Phyllanthus Neruri plant

2018-09-05T09:25:47Z

Title: Removal of nitrites from waste waters using adsorbents derived from Phyllanthus Neruri plant Authors: Suneetha, M; Ravindhranath, K Abstract: The bio-sorbents prepared from leaves, stems and leaves ashes of Phyllanthus Neruri plants have been investigated for their adsorption abilities towards nitrites from polluted waters adopting batch methods of extractions. Physicochemical parameters such as pH, sorbent dosage, initial nitrite concentration and time of agitation have been optimized for the maximum extraction of nitrites. The effect of commonly found co-ions on the % of extraction of nitrite has been investigated. Freudlich and Langmuir isotherms are plotted and correlation coefficient (R²) value confirmed that the adsorption follows the Langmuir isotherm indicating formation of monolayer on the surface of the adsorbents. Kinetics of adsorption process is analyzed using pseudo first-order and pseudo-second-order equations and found the good correlation with pseudo second-order model. The methodologies are successfully applied in removing nitrites from water samples collected from polluted lakes. Page(s): 345-352