scholarly journals The use of photocatalytic degradation to improve the quality of crude refinery effluent

2018 ◽  
Author(s):  
◽  
Dushen Bisetty Naidoo
Keyword(s):  
Photocatalytic Degradation ◽  
South African ◽  
Catalyst Concentration ◽  
Phenol Degradation ◽  
Degradation Process ◽  
Effluent Treatment ◽  
Optimum Conditions ◽  
Effluent Quality ◽  
Refinery Effluent ◽  
South African Water

Water plays a fundamental role in sustaining life on Earth. Water is largely used by industries to support their processes and utilities. Through growing industrialisation, each year more and more wastewater is generated and the demand for water rises rapidly. The incorrect and unsustainable use of water is placing a great strain on the South African water supply. Much emphasis is now being placed on industries re-using and treating their effluent and wastewater. Of recent, government has placed stringent specifications for industrial effluent quality and industry find it difficult to continuously improve their effluent quality to be within acceptable limits. Crude refineries are major contributors to wastewater, producing effluent comprising largely of Oil, grease and hydrocarbon. Much focus is placed on finding alternate means of wastewater treatment to assist with the removal of oil and hydrocarbon contaminants. More effluent treatment processes need to be explored to ensure industries operate in a sustainable manner and do not place unnecessary strain on the South African water supply. Photocatalytic degradation is a wastewater treatment technique that has drawn a lot of attention in the last decade. This is an Advanced Oxidation Process (AOP) which involves the production of a hydroxyl radical (OH-) which is then used for the degradation of organic contaminants. The degradation converts the organic pollutants into CO2 and H2O. A synthetic crude refinery effluent was developed and underwent the photocatalytic degradation process. The catalyst concentration was varied at 2 g/L, 5 g/L and 8 g/L. The oxidation reaction took place over time intervals of 30, 60 and 90 minutes and aeration to the reaction vessel was supplied at 0.768 L/min, 1.11 L/min and 1.48 L/min. This photodegradation took place under UV light conditions. The degradation process was conducted with the aim of evaluating the degradation of oil and phenol in crude refinery effluent. Sulphates were also monitored to observe if an effect was noticed. Design of Experiment (DOE) involved the development of experimental run matrices for a multilevel factorial design, Central Composite Design (CCD) and Box-Behnken Design (BBD) model. Randomized runs were then conducted as per the design matrix for each model. Model verification and evaluation was then conducted and the best suited degradation models were selected. It was observed that the best fitted model for the degradation of oil in water was the BBD. The best design model for phenol degradation was the CCD. Throughout the photocatalytic degradation process, it was noted that no change took place with the sulphates. The models were then optimised to determine the optimum degradation conditions. This was carried out using Response Surface Methodology (RSM) techniques. The CCD model yielded a combined oil and phenol degradation of 71.5%. This occurred at a catalyst concentration of 2.07g/L, a run time of 90 minutes and an air flow rate of 0.768L/min. The BBD model produced a combined oil and phenol degradation of 68%. This took place at a catalyst concentration of 2 g/L, a run time of 30 minutes and an air flow rate of 1.04 L/min. pH were monitored throughput the degradation process and both these models yielded output products within the stipulated pH band. The testing of a local crude refinery effluent was conducted using the CCD and BBD optimum conditions. When using the CCD optimum conditions degradation of 76.98% and 84.21% was observed for both oil and phenol respectively. The BBD optimum conditions yielded a degradation of 83.33% for oil and 78.95% for phenol. This indicated that the photocatalytic process can be considered for degrading crude refinery effluent as its products met the specifications of municipal industrial waste water. The above results clearly indicate a positive outcome for the treatment method of photocatalytic degradation on the synthetic crude refinery effluent. This technique can therefore be further explored when considering crude effluent treatment and the treatment advantages should be used by all industries to improve effluent quality and allow for more sustainable and environmentally friendly operations.

Modeling and Optimization of Photocatalytic Degradation of Methylene Blue Using Lanthanum Vanadate

2020 ◽  
Vol 1008 ◽  
pp. 97-103
Author(s):  
Mahmoud Samy ◽  
Mona G. Ibrahim ◽  
Mohamed Gar Alalm ◽  
Manabu Fujii
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Degradation ◽  
Removal Efficiency ◽  
Textile Industry ◽  
Degradation Process ◽  
Optimum Conditions ◽  
Photo Degradation ◽  
Operational Conditions ◽  
Degradation Rates ◽  
Effects Of Ph

Methylene blue (MB) is one of the commonly used dyes in the textile industry and can be used as a model pollutant for the textile industry wastewater. In this work, the photocatalytic degradation of MB by synthesized nanoparticles of lanthanum vanadate (LaVO4) was assessed. The effects of pH, initial MB concentration and catalyst dose on the removal performance of MB were investigated and measuring the optimum values of these operational conditions was performed using response surface methodology (RSM). Catalyst dose of 0.43 g/L, initial MB concentration of 5.0 mg/L, and pH of 6.86 were found to be the optimum conditions in reaction time of 60 min. A mathematical model was formed to relate the removal efficiency of MB to the aforementioned operating parameters. The removal efficiency of MB was 91% without any scavengers at a catalyst dose of 0.3 g/L, pH of 7 and initial MB concentration of 10 mg/L. The trapping experiments confirmed the participation of different reactive species in the photo-degradation process. The degradation rates of MB were 91%, 86%, 81%, 77.70% and 72% in five successive runs using LaVO4.

scholarly journals Photocatalytic Degradation of Acid Yellow 36 Using Zinc Oxide Photocatalyst in Aqueous Media

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Sajjad Khezrianjoo ◽  
Hosakere Doddarevanna Revanasiddappa
Keyword(s):  
Photocatalytic Degradation ◽  
Catalyst Concentration ◽  
Heterogeneous Medium ◽  
Batch Reactor ◽  
Aqueous Media ◽  
Electrical Energy ◽  
Degradation Process ◽  
Active Species ◽  
Catalyst Loading ◽  
Order Of Magnitude

A detailed investigation of photocatalytic degradation of Acid Yellow 36 (AY36) has been carried out in aqueous heterogeneous medium containing ZnO as photocatalyst in a batch reactor. The effects of some parameters such as pH, catalyst loading, and ethanol concentration were examined. Solutions with initial concentration of 50 mg L−1 of dye, within the range of typical concentration in textile wastewaters, were treated at natural pH of 6.93 and catalyst concentration of 1 g L−1 after 180 min irradiation. Investigations on the active species indicated that hydroxyl radicals play the major role in the process. Experiments showed that the most efficient pH on the removal of the dye with photocatalytic degradation process was 8; however, acidic pH was favored for the dark surface adsorption. Electrical energy consumption per order of magnitude for photocatalytic degradation of AY36 has been also determined.

scholarly journals Analysis of Photocatalytic Degradation of Phenol with Exfoliated Graphitic Carbon Nitride and Light-Emitting Diodes Using Response Surface Methodology

Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 898
Author(s):  
Adeem Ghaffar Rana ◽  
Mirjana Minceva
Keyword(s):  
Response Surface Methodology ◽  
Photocatalytic Degradation ◽  
Response Surface ◽  
Carbon Nitride ◽  
Light Emitting Diodes ◽  
Catalyst Concentration ◽  
Phenol Degradation ◽  
Graphitic Carbon ◽  
Graphitic Carbon Nitride ◽  
Light Emitting

Response surface methodology (RSM) involving a Box–Benkhen design (BBD) was employed to analyze the photocatalytic degradation of phenol using exfoliated graphitic carbon nitride (g-C3N4) and light-emitting diodes (wavelength = 430 nm). The interaction between three parameters, namely, catalyst concentration (0.25–0.75 g/L), pollutant concentration (20–100 ppm), and pH of the solution (3–10), was examined and modeled. An empirical regression quadratic model was developed to relate the phenol degradation efficiency with these three parameters. Analysis of variance (ANOVA) was then applied to examine the significance of the model; this showed that the model is significant with an insignificant lack of fit and an R2 of 0.96. The statistical analysis demonstrated that, in the studied range, phenol concentration considerably affected phenol degradation. The RSM model shows a significant correlation between predicted and experimental values of photocatalytic degradation of phenol. The model’s accuracy was tested for 50 ppm of phenol under optimal conditions involving a catalyst concentration of 0.4 g/L catalysts and a solution pH of 6.5. The model predicted a degradation efficiency of 88.62%, whereas the experimentally achieved efficiency was 83.75%.

KINETIC CONSTANTS DETERMINATION OF PETROLEUM REFINERY EFFLUENT TREATMENT IN A UASB REACTOR USING RSM

2017 ◽  
Vol 16 (1) ◽  
pp. 121-130 ◽  
Author(s):  
Seyyed Mohammad Mousavi ◽  
Seyed Omid Rastegar ◽  
Seyed Abbas Shojaosadati ◽  
Soheila Sheibani
Keyword(s):  
Petroleum Refinery ◽  
Kinetic Constants ◽  
Effluent Treatment ◽  
Uasb Reactor ◽  
Refinery Effluent ◽  
Petroleum Refinery Effluent

Developments in Legislation Related to Treatment of Petroleum Refinery Effluents: A Canadian Overview

1989 ◽  
Vol 24 (3) ◽  
pp. 345-354
Author(s):  
David L. Putnam
Keyword(s):  
Drinking Water ◽  
Petroleum Refinery ◽  
Current Knowledge ◽  
Environmental Regulations ◽  
Public Concern ◽  
Effluent Quality ◽  
Refinery Effluent ◽  
Petroleum Refinery Effluent

Abstract Public concern over toxic contaminants in drinking water and the environment in general has put increasing pressure on governments to develop and enforce stringent environmental regulations. An overview of developments in Canadian federal and provincial legislation related to the regulation of petroleum refinery effluent quality is provided. Current knowledge of Canadian petroleum refinery effluent quality and level of treatment is summarized.

scholarly journals Photodegradation of Phenolic Compounds from Water in the Presence of a Pd-Containing Exhausted Adsorbent

2020 ◽  
Vol 10 (23) ◽  
pp. 8440
Author(s):  
Lavinia Lupa ◽  
Laura Cocheci ◽  
Bogdan Trica ◽  
Adina Coroaba ◽  
Adriana Popa
Keyword(s):  
Phenol Degradation ◽  
Magnesium Silicate ◽  
Degradation Process ◽  
Liquid Ratio ◽  
Phenol Solution ◽  
Secondary Sources ◽  
Great Economic Importance ◽  
Phenol Photodegradation ◽  
Cyphos Il 101 ◽  
Solid Liquid

A closed-cycle technology regarding the use of an exhausted Pd-based adsorbent as a photocatalyst in the degradation process of phenol is presented. Pd (II) represents a precious metal of great economic importance. Its obtained from natural sources become more difficult to achieve. Therefore, also considering the regulations of the “circular economy,” its recovery from secondary sources turn out to be a stringent issue in the last years. Pd(II) ions are removed from aqueous solution through adsorption onto Florisil (an inorganic solid support—magnesium silicate) impregnated with Cyphos IL 101 (trihexyl tetradecyl phosphonium chloride). It was observed that the presence of the ionic liquid (IL) in the adsorbent structure doubles the adsorption efficiency of the studied materials. The newly obtained Pd-based photocatalyst was exhaustively characterized and was used in the degradation process of phenol from aqueous solutions. The phenol degradation process was studied in terms of the nature of the photocatalyst used, time of photodegradation and solid: liquid ratio. It was observed that both the presence of IL and Pd lead to an increase in the efficiency of the phenol degradation process. The new Pd-based photocatalyst could be efficiently used in more cycles of phenol photodegradation processes. When is used as a photocatalyst the Florisil impregnated with IL and loaded with 2 mg/g of Pd, a degree of mineralization of 93.75% is obtained after 180 min of irradiation of a phenol solution having a concentration of 20 mg/L and using a solid:liquid ratio = 1:1.

Overview of the water policy process in South Africa

Water Policy ◽  
2006 ◽  
Vol 8 (6) ◽  
pp. 505-528 ◽  
Author(s):  
Christo De Coning
Keyword(s):  
South Africa ◽  
South African ◽  
Policy Process ◽  
Water Policy ◽  
Process Model ◽  
Transfer Of Knowledge ◽  
The South ◽  
Systematic Analysis ◽  
Policy And Strategy ◽  
South African Water

This research article provides an overview of the policy process followed by the South African Government in developing and implementing the White Paper on a National Water Policy for South Africa between 1994 and 2003. The research is based on a report published by the South African Water Research Commission (WRC), which formed part of a project entitled: Consolidation and Transfer of Knowledge and Experience Gained in the Development and Implementation of Water and Related Policy in South Africa (WRC Project number K5/1295). An attempt was made in the research project to solicit lessons of experience from the last ten years and to suggest findings regarding future options. It was found that valuable experience exists that is relevant not only to present and future policy and strategy initiatives in South Africa but also to policy process development in a regional and global context. The review of the water policy process has included a deliberate attempt to apply a selected policy process model to the South African water policy process in order to attempt a systematic analysis of the process. Specific findings were made regarding policy and strategy processes, institutional capacity and policy research in the water sector. The findings of the study included a confirmation of the technical quality of the policy and identification of several opportunities and priorities in the implementation of water policy.

scholarly journals Conventional and High Resolution Chemical Characterization to Assess Refinery Effluent Treatment Performance

Chemosphere ◽  
2021 ◽  
pp. 130383
Author(s):  
M. Hjort ◽  
K.H. den Haan ◽  
G. Whale ◽  
J. Koekkoek ◽  
P.E.G. Leonards ◽  
...  
Keyword(s):  
High Resolution ◽  
Chemical Characterization ◽  
Effluent Treatment ◽  
Refinery Effluent ◽  
Treatment Performance
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