Comparison of Five Advanced Oxidation Processes for Degradation of Pesticide in Aqueous Solution

The study compared the technical efficiency and economic cost of five advanced oxidation processes (Fenton, UV photo-Fenton, solar photo-Fenton, UV/TiO2/H2O2 and FeGAC/H2O2) for degradation of the pesticides chlorpyrifos cypermethrin and chlorothalonil in aqueous solution. The highest degradation in terms of COD and TOC removals and improvement of the biodegradability (BOD5/COD ratio) index (BI) were observed to be (i) Fenton - 69.03% (COD), 55.61% (TOC), and 0.35 (BI); (ii) UV photo-Fenton -78.56% (COD), 63.76% (TOC) and 0.38 (BI);  (iii) solar photo-Fenton - 74.19% (COD), 58.32% (TOC) and 0.36 (BI); (iv) UV/TiO2/H2O2 - 53.62% (COD), 21.54% (TOC), and 0.26 (BI); and  (v) the most technical efficient and cost effective process was FeGAC/H2O2. At an optimum condition (FeGAC 5 g/L, H2O2 100 mg/L, and reaction time of 60 min at pH 3), the COD and TOC removal efficiency were 96.19 and 85.60%, respectively, and the biodegradation index was 0.40. The degradation rate constant and cost were 0.0246 min-1 and $0.74/kg TOC, respectively. The FeGAC/H2O2 process is the most technically efficient and cost effective for pretreatment of the pesticide wastewater before biological treatment.

Comparison of Five Advanced Oxidation Processes for Degradation of Pesticide in Aqueous Solution

The study compared the technical efficiency and economic cost of five advanced oxidation processes (Fenton, UV photo-Fenton, solar photo-Fenton, UV/TiO2/H2O2 and FeGAC/H2O2) for degradation of the pesticides chlorpyrifos cypermethrin and chlorothalonil in aqueous solution. The highest degradation in terms of COD and TOC removals and improvement of the biodegradability (BOD5/COD ratio) index (BI) were observed to be (i) Fenton - 69.03% (COD), 55.61% (TOC), and 0.35 (BI); (ii) UV photo-Fenton -78.56% (COD), 63.76% (TOC) and 0.38 (BI);  (iii) solar photo-Fenton - 74.19% (COD), 58.32% (TOC) and 0.36 (BI); (iv) UV/TiO2/H2O2 - 53.62% (COD), 21.54% (TOC), and 0.26 (BI); and  (v) the most technical efficient and cost effective process was FeGAC/H2O2. At an optimum condition (FeGAC 5 g/L, H2O2 100 mg/L, and reaction time of 60 min at pH 3), the COD and TOC removal efficiency were 96.19 and 85.60%, respectively, and the biodegradation index was 0.40. The degradation rate constant and cost were 0.0246 min-1 and $0.74/kg TOC, respectively. The FeGAC/H2O2 process is the most technically efficient and cost effective for pretreatment of the pesticide wastewater before biological treatment. Copyright © 2018 BCREC Group. All rights reserved Received: 26th July 2017; Revised: 26nd September 2017; Accepted: 27th September 2017; Available online: 22nd January 2018; Published regularly: 2nd April 2018 How to Cite: Affam, A.C., Chaudhuri, M., Kutty, S.R.M. (2018). Comparison of Five Advanced Oxidation Processes for Degradation of Pesticide in Aqueous Solution. Bulletin of Chemical Reaction Engineering & Catalysis, 13 (1): 179-186 (doi:10.9767/bcrec.13.1.1394.179-186

A review of recent developments in flammability of polymer nanocomposites

Polymer nanocomposite flame retardancy has become a critical parameter in industrial material application. Recent environmental policies have prohibited the incorporation of halogenated flame-retardant compounds into polymers owing to the high level of environmental degradation caused by high levels of toxic gas and smoke emission. The demand for zero-halogen flame-retardant compounds by both researchers and manufacturers is due to the inherent advantages accruable from their incorporation like very minimal toxic emission, minimal smoke release, zero corrosive gas release, reduced corrosion activities and absence of dripping in fire condition. This has necessitated the quest for eco-compliant replacements for halogenated flame suppressants. Recent insight has shown the eco-compliancy of exfoliated graphene nanoplatelets as flame retardants when incorporated into polymer nanocomposites (PNCs). Relative to the propensity to retard flame, increasing quantities of exfoliated graphene nanoplatelets have exhibited the capability to significantly repress critical flammability parameters like heat release rate (HRR), peak HRR (PHRR), rate of carbon monoxide production, smoke production rate and total mass loss rate while simultaneously increasing limiting oxygen index, time of ignition and total PHRR, thereby retarding flammability and creating better chance to reduce loss and casualty in real-life fire situation through the formation of even layers of carbonaceous char in the condensed phase capable of efficiently suppressing the thermal decomposition caused by oxygen and heat to the polymer matrix and cutting off the flaming path. This paper gives an insight into recent developments in flame retardancy of PNCs, with special emphasis on the flame-retardancy propensity of exfoliated graphite nanoplatelets

Removal of nutrients from pulp and paper biorefinery effluent : operation, kinetic modelling and optimization by response surface methodology

This study investigated the effectiveness of extended aeration system (EAS) and rice straw activated carbon-extended aeration system (RAC-EAS) in the treatment of pulp and paper biorefinery effluent (PPBE). RAC-EAS focused on the efficient utilization of lignocellulosic biomass waste (rice straw) as a biosorbent in the treatment process. The experiment was designed by response surface methodology (RSM) and conducted using a bioreactor that operated at 1–3 days hydraulic retention times (HRT) with PPBE concentrations at 20, 60 and 100%. The bioreactor was fed with real PPBE having initial ammonia-N and total phosphorus (TP) concentrations that varied between 11.74 and 59.02 mg/L and 31–161 mg/L, respectively. Findings from the optimized approach by RSM indicated 84.51% and 91.71% ammonia-N and 77.62% and 84.64% total phosphorus reduction in concentration for EAS and RAC-EAS, respectively, with high nitrification rate observed in both bioreactors. Kinetic model optimization indicated that modified stover models was the best suited and were statistically significant (R 2 ≥ 0.98) in the analysis of substrate removal rates for ammonia-N and total phosphorus. Maximum nutrients elimination was attained at 60% PPBE and 48 h HRT. Therefore, the model can be utilized in the design and optimization of EAS and RAC-EAS systems and consequently in the prediction of bioreactor behavior

Circular economy potential and contributions of petroleum industry sludge utilization to environmental sustainability through engineered processes - a review

The petroleum industry activities unavoidably generate a large quantity of sludge named Petroleum industry sludge (PIS). The generation rate has been increasing because of the ascending energy demand. It is a potential energy resource. PIS has been shown to contain hazardous constituents that may have negative consequences on the environment and public health. Thus, the treatment and disposal of this waste is a global issue. Numerous treatment methods have been demonstrated to reduce sludge volume and toxicity and recover petroleum components. The sludge qualities affect how effective they are. These treatment strategies can reduce the toxic substances in sludge and reduce their detrimental effects on human health and the environment. However, because of the sludge's tenacious character, only a few technologies can meet strict environmental laws while using a sizable amount of water, electricity, and chemicals. PIS treatment methods that are both waste-free and cost-effective are currently unavailable. In terms of environmental engineering significance, this study adopted the systematic review to discuss the waste to resource potential applications of PIS for reusability in sustainable construction, wastewater treatment applications, and gas generation. PIS application ineffective microorganism biofertilizer production, levan production, rubber tires manufacturing, metal catalysts synthesis, carbon–clay composites for use in sensors and electronic devices were also discussed. That is not enough, this review also found that the adoption of the circular economy that represents a new direction to create value and prosperity by elongating product lifespan and moving the waste from the end of the supply chain to the outset is very important. Thus, the circular economy potential of PIS to achieve self-cycle operation through the concept of “wastes-treat-wastes” in the petroleum industry was extensively discussed

ADVANCED OXIDATION PROCESS-SEQUENCING BATCH REACTOR TREATMENT OF PESTICIDE WASTEWATER

Pesticides are enumerated among persistent organic pollutants (POPs) which make up the emerging contaminants in the aquatic environment. The risk inherent to pesticide pollution is prominent due to their low solubility in water, low sorption affinity to soils, toxicity, chemical stability, bioaccumulation and low biodegradability. The major sources of pollution by pesticides are drainage water from intensive agriculture, including water from washing pesticides containers and application equipment, and effluent from agricultural industries and pesticide manufacturing plants. The overall objective of the study is development of an effective treatment system for pesticide wastewater from a company producing chlorpyrifos. cypermethrin and chlorothalonil pesticides. There has been no work reported on complete treatment of pesticide wastewater containing these pesticides. The study was conducted in two phases. In phase I, five advanced oxidation processes (AOPs) (Fenton, UV photo-Fenton, solar photo-Fenton, UV/Ti02/H20 2 and FeUAC/H202) were applied for degradation of chlorpyrifos, cypermethrin and chlorothalonil pesticides in aqueous solution

OPERATIONAL PERFORMANCE OF VERTICAL UPFLOW ROUGHING FILTER FOR PRE-TREATMENT OF LEACHATE USING LIMESTONE FILTER MEDIA

This study was conducted to investigate the removal of COD, BOD, turbidity and colour from leachate using vertical upflow filtration technique. Limestone media with a density of 2554 kg/m³ was crushed and graded in sizes of 48 mm, 812 mm and 12-18 mm. Trial runs were done before the main experiment at an interval of 24 h analysis. Leachate was between pH 7.94 to 8.12 before experiments but increased to pH 8.42 after the filtration process. Maximum headloss at steady flow rate 20mL/min was 0.5 cm. The optimum treatment was achieved with 4–8 mm, 8–12 mm & 12–18 mm media size in combination and removal efficiency was 22 to 81%, 22 to 75%, 32 to 86%, and 36 to 62% for BOD, COD, turbidity and colour, respectively. Vertical upflow roughing filter can be used for pre-treatment of leachate before further treatment

Degradation of Pesticide Chlorothalonil by Visible Light-Responsive Photocatalyst Ferrioxalate and under Solar Irradiation

Ferrioxalate is a visible light-responsive photocatalyst. The solar ferrioxalate/ process has high degradation efficiency because ferrioxalate is able to absorb light strongly at longer wavelength and generates hydroxyl radical with high quantum yield. Degradation of pesticide chlorothalonil in aqueous solution by ferrioxalate/ under solar irradiation was examined. The optimum operating conditions for treatment of a 300 mg/L chlorothalonil aqueous solution were obtained by using the central composite design of the response surface methodology. Under the optimum operating conditions (/COD molar ratio 2.75, /Fe3+ molar ratio 75, /C2H2O4 molar ratio 37.5, reaction time 90 min, and pH 3), COD, NH3-N, and TOC removal of 75.71, 47.11, and 54.33%, respectively, was achieved and the biodegradability (BOD5/COD ratio) improved from zero to 0.42. Model prediction and actual removal were in close agreement (<4% error). The solar ferrioxalate/H2O2 process is effective in pretreatment of the chlorothalonil aqueous solution for biological treatment

Can Induced Magnetic Field Enhance Bioprocesses? - Review

This review presents a compilation of works with particular interest in the application of static magnetic field (SMF) to biological systems, wastewater treatment and few available reports on microbial granulation technology. It also highlights the effects of SMF on biological systems and wastewater treatment process. With an increasing need for environmentally conscious solutions to water purification and disinfection, wastewater treatment, bioremediation and other cheap alternative means, the application of SMF in biological water and wastewater treatment without increase in chemicals required may become an attractive option. Application of SMF has been reported to be successful in a number of fields including treatment of wastewater. However, there are sparse reports on SMF application in the formation and development of microbial granule and production of extracellular polymeric substances (EPS). Achieving a short start-up time in a bioreactor towards the development of microbial granule is of paramount importance in granulation technology. Ascertaining how effective varying strength of SMF and other input variables may enhance the microbial granule with respect to its physical, chemical and biological characteristics requires further research