Grease Removal Research Articles

Integrated processes for produced water polishing: Enhanced flotation/sedimentation combined with advanced oxidation processes

In this study, bench scale dissolved air flotation (DAF) and settling processes have been studied and compared to a novel flotation technology based on the use of glass microspheres of limited buoyancy and its combination with conventional DAF, (Enhanced DAF or E-DAF). They were evaluated as pretreatments for advanced oxidation processes (AOPs) to polish produced water (PW) for reuse purposes. Settling and E-DAF without air injection showed adequate turbidity and oil and grease (O&G) removals, with eliminations higher than 87% and 90% respectively, employing 70 mg L−1 of FeCl3 and 83 min of settling time, and 57.9 mg L−1 of FeCl3, 300 mg L−1 of microspheres and a flocculation rate of 40 rpm in the E-DAF process. A linear correlation was observed between final O&G concentration and turbidity after E-DAF. In order to polish the O&G content of the effluent even further, to remove soluble compounds as phenol and to take advantage of residual iron after these treatments, Fenton and photo-Fenton reactions were essayed. After 6 h of the Fenton reaction at pH 3, the addition of 1660 mg L−1 of H2O2 and 133 mg L−1 of iron showed a maximum O&G elimination of 57.6% and a phenol removal up to 80%. Photo-Fenton process showed better results after 3 h, adding 600 mg L−1 of H2O2 and 300 mg L−1 of iron, at pH 3, with a higher fraction of elimination of the O&G content (73.7%) and phenol (95%) compared to the conventional Fenton process.

Photocatalytic treatment of oil and grease spills in wastewater using coated N-doped TiO2 polyscales under sunlight as an alternative driving energy

To enhance the overall efficiency of oil and grease removal in wastewater coated N-doped TiO2 photocatalytic polyscales were fabricated through sol–gel technique. The materials fabricated were characterized using powder X-ray diffraction, Fourier transmission infrared spectroscopy, scanning electron microscopy, and UV–Vis spectroscopy. In order to enhance degradation efficiency of organic pollutant under natural sun light, shifting of absorption range of TiO2 to visible spectrum, various modifications such as surface modification and size optimization were carried out by doping of nitrogen under sol–gel processes. To ease recovery of suspended catalysts from aqueous media, the coated N-doped TiO2 were prepared by decorating photocatalytic particles onto suitable substrates. N-doped TiO2 polyscales with desired functionalities were coated onto the spherical supporting substrates using a binding agent. The photocatalytic treatment studies clearly indicated the considerable level of the oil and grease and other organic pollutants removal from wastewater (up to 85–90 % ± 2) using coated N-doped TiO2 under natural sunlight as an alternative driving energy source. Removal of oil and grease along with other organic pollutants in wastewater using coated N-doped TiO2 polyscales is a versatile, economical, and environmental friendly technique due to the ease of handling and recovery, utilization of natural sunlight which is renewable energy source.

Comparative Analysis on the Effectiveness of the Different Brands of Commercialized Dishwashing Liquids

This study was conducted to determine the effectiveness of different brand of commercialized dishwashing liquid namely: Joy, Axion, Surf, Mr. Clean, specifically it was conducted to compare the effectiveness of different brands of commercialized dishwashing liquid tested on Cagayan State University College of Medical Technology Clinical Laboratory using the organisms E. coli and Staphylococcus aureus. Likewise, the study determined the zone of clearance in the oil and grease. Both had used alcohol as a positive control and water as a negative control. The analysis of variance in the three replication and six treatments was used in the study. Based on the results of the study, it was found out that the four commercialized dishwashing liquid exhibited an antibacterial activity on the two test microorganism. Joy showed greater inhibitory activity on the test microorganism, followed by Axion, Surf and Mr. Clean. On the other hand, the results of the analysis of variance showed that there is no significant effect on the elimination of food borne bacteria and as to the removal of oil and grease. Commercialized dishwashing liquid are more effective against the elimination of E. coli then Staphylococcus aureus, and in the removal of oil and grease than alcohol and water.

Wastewater Treatment Works (WwTW) as a Source of Microplastics in the Aquatic Environment.

Municipal effluent discharged from wastewater treatment works (WwTW) is suspected to be a significant contributor of microplastics (MP) to the environment as many personal care products contain plastic microbeads. A secondary WwTW (population equivalent 650 000) was sampled for microplastics at different stages of the treatment process to ascertain at what stage in the treatment process the MP are being removed. The influent contained on average 15.70 (±5.23) MP·L(-1). This was reduced to 0.25 (±0.04) MP·L(-1) in the final effluent, a decrease of 98.41%. Despite this large reduction we calculate that this WwTW is releasing 65 million microplastics into the receiving water every day. A significant proportion of the microplastic accumulated in and was removed during the grease removal stage (19.67 (±4.51) MP/2.5 g), it was only in the grease that the much publicised microbeads were found. This study shows that despite the efficient removal rates of MP achieved by this modern treatment plant when dealing with such a large volume of effluent even a modest amount of microplastics being released per liter of effluent could result in significant amounts of microplastics entering the environment. This is the first study to describe in detail the fate of microplastics during the wastewater treatment process.

REMOVAL OF OIL AND GREASE FROM WASTEWATER USING NATURAL ADSORBENTS

There are several pollutants that can harm our environment. Oil and grease are one of the examples of a pollutant that can cause a severe environmental problem. The highest concentration of oil and grease inside the sewer system can cause the sewer to clog that can lead to overflow. It can affect not only to the environment but can also affecting our health. There are various methods of oil and grease removal that one of the examples is by using adsorption method. This method commonly uses activated carbon that is one of the effective adsorbents. Although effective, the cost for activated carbon is expensive thus a study was conducted by using agricultural residues as alternative adsorbents for oil and grease removal. This study objective is to determine the ability of two adsorbents, which are sugarcane bagasse and banana pith as an adsorbent in removing oil and grease from wastewater. It involved the characterization of adsorbent and the performance studies of the adsorbent. The adsorbent was characterized in term of physical and chemical characterization. Dosage and contact time are the parameter used for performance studies, to see the ability of adsorbents in removing oil and grease.

An Insight into Oil and Grease Removal from Wastewater from Petroleum and Refinery Industries

An Insight into Oil and Grease Removal from Wastewater from Petroleum and Refinery Industries

전해액의 Fe 농도에 의한 크롬도금 탈락 연구

The internal chromium plating of a long-axis tube is widely used in military and industrial application, with the thick hard plating formed using a mixed solution of Chromium acid and catalytic . A large-caliber gun can endure a high explosive force as a result of the increased stiffness and wear resistance provided by this internal hard chromium surface. The internal chromium layer of a tube is prone to exfoliation caused by the high kinetic energy of the projectile and high pressure of the explosion. Therefore, we reviewed the plating process. Chromium plating comprises many steps, including the removal of Grease, water cleaning, electrolytic abrasion, etching, plating, water cleaning, and hydrogen brittleness removal. The exfoliated chromium plating layer is affected by the adhesion property of the plating. In particular, the Fe concentration of the electrolyte affects the adhesion property. The optimum Fe concentration for effectively suppressing the exfoliation of the plating layer was established by using a scanning electron microscope to determine the surface roughness, and the effectiveness was proved in an adhesion test, etc.

A green alternative for oily wastewater treatment: lipase from Acinetobacter haemolyticus NS02-30

Biological treatment of wastewater is negatively affected by high concentrations of oil and grease, which decrease the oxygen transfer rate in the aerobic process by forming a layer on the water surface, making removal of oil and grease from manufacturing wastewater essential. However, the most common currently used techniques are inadequate as well as costly, and chemical methods create environmental pollution. By contrast, fermentation can be used to produce extracellular microbial lipases relatively cheaply and in large quantities for industrial use. Biological methods that use lipase enzymes also represent an appropriate, “green” choice for removing oil and grease from wastewater. This study identified and characterized a novel lipase produced from bacteria isolated by screening soil and olive pomace samples for lipolytic activity. The bacteria was subsequently identified as Acinetobacter haemolyticus, and the lipase produced from this bacteria (LipAH02–30) was then purified and characterized. Findings are presented as means ± SD. Enzyme Km and Vmax were 0.8mM and 3.833 mmol/ml/min, respectively. Optimal temperature and pH for enzyme activity were identified as 40°C and 9.0, with good stability exhibited at temperatures ranging between 10 and 30°C and a pH range of 5.0–11.0. The effects of organic solvents, metal ions, surfactants, commercial detergents, enzyme inhibitors, oxidizing agents, protease and boric acid on LipAH02–30 activity were also examined. The enzyme was found to be highly stable at +4°C, displaying 90% activity even after 60 d, and to be effective in hydrolyzing oils found in kitchen wastewater. The high stability demonstrated by LipAH02–30 over a wide range of temperatures and pHs, along with its ability to maintain its activity in the presence of various surfactants, oxidizing agents, proteases and commercial detergents, indicates it to be an effective solution for the treatment of lipid-rich wastewater.

New insights on the removal of mineral oil from oil-in-water emulsions using cork by-products: Effect of salt and surfactants content

The present work focuses on the use of two different cork by-products, raw cork (RAC) and regranulated cork (RGC), as sorbents for oil and grease (O&G) removal from mineral oil-in-water (O/W) emulsions (lubricant oil 15W-40). Acidic conditions favored O&G removal from emulsions using cork granules, achieving values of about 90%. RGC showed the highest O&G removal capacity, associated with its thermal treatment with water vapor at 380°C, which increased its hydrophobicity. Sorption isotherms at 25°C were determined at different pH values (2, 4 and 6). Freundlich and linear models were able to fit well the equilibrium data regarding O&G removal using RGC, suggesting that the major sorption mechanism is partitioning (log KOW around 4.0). Kinetic studies showed that O&G removal rates using RGC were faster (<100min) than those using RAC (≈300min). Moreover, oil sorption onto cork is favored by acidic conditions, achieving values of 90mgg−1 at pH 2 (equilibrium oil concentration in the liquid phase of 4.5mg/L). In order to improve the oil uptake onto regranulated cork at near neutral pH, the use of different salts (NaCl, Na2SO4 and MgCl2) and surfactants (anionic: sodium dodecyl sulfate – SDS, cationic: hexadecyltrimethyl ammonium – HDTMA and nonionic: Tween 80) was tested. The best results were achieved using 0.1M NaCl and Tween 80. This paper also proposes a mass transfer model based on cork and oil properties, which adequately predicts the kinetic experimental data and attests that the rate-limiting step in the sorption process is the external fluid film resistance.

Suspended Solid, Color, COD and Oil and Grease Removal from Biodiesel Wastewater by Coagulation and Flocculation Processes

Coagulation and flocculation are essential processes in a number of diverse disciplines, including biochemistry, cheese manufacturing, rubber manufacturing, and in water and waste water treatment. Coagulation-flocculation is effective for removing high concentration organic pollutants and heavy metals in water and wastewater. However, limited information exists on the efficiency of this coagulation-flocculation process for biodiesel wastewater treatment. The biodiesel wastewater is basic (alkaline), with a high content of oil and grease, and a low content of nitrogen and phosphorus. As such, biological treatment of the biodiesel wastewater is expected to be very difficult. For this reason supportive physic-chemical methods are often used. Although one of the most frequently employed method is coagulation. Therefore, this study was conducted to investigate the efficiency of coagulation and flocculation processes for removing suspended solid (SS), color, COD and oil and grease from biodiesel wastewater. Aluminum sulfate, polyaluminum chloride, ferric chloride and ferric sulfate as a coagulant in biodiesel wastewater treatment were studied using a standard jar test apparatus. The result shows that, at the optimum dose of PAC (300mg/L), the percentage removal of SS, color, COD and oil and grease respectively 97%, 95%, 75% and 97% compared to only 92%, 92%, 53% and 99% at the optimal dose alum (500mg/L), 95%, 93%, 63% and 97% at the optimum dose of ferric chloride (350mg/L) and 88%, 88%, 54% and 94% at the optimum dose of ferric sulfate (450mg/L). The effect of coagulant dosages on suspended solid (SS), color, COD and oil and grease removal showed similar trend and PAC was found to be superior was observed at reasonable lower amount of coagulant i.e. 300mg/L. The results showed that coagulation-flocculation is effective as a pre-treatment for treating biodiesel wastewater.

Removal of Oily Wastewater Using Chitosan-filled Filter Media

The aim of this research is to evaluate the feasibility of the fibrous media for removal of total suspended solid and oil grease from palm oil mill effluent (POME). Wet lay-up method was adopted for filter fabrication where empty fruit bunches (EFB) were matted together with chitosan in non-woven manner. Chitosan-filled filter media were tested for their ability to reduce Total Suspended Solids (TSS) and Oil &amp; Grease (O&amp;G) from palm oil mill effluent. Filtration process results indicated that chitosan-filled filter media filtration only removed up to 28.14% of TSS and 29.86% of O&amp;G.

Comparative study of electrochemical wastewater treatment processes for bilge water as oily wastewater: A kinetic approach

In this study treatability of bilge water was investigated by electrochemical processes: electrocoagulation/electroflotation process and also the electro-fenton process as an indirect electrooxidation process. As the seawater is mixed into bilge water, the chloride content and the conductivity of bilge water are quite high, which is a great advantage in terms of electrochemical wastewater treatment. Treatability of bilge water by electrocoagulation/electroflotation process is investigated by using aluminum and iron electrodes in accordance with pH, time, temperature and current density. When the aluminum and iron electrodes are compared in electrocoagulation–electroflotation process, the results clearly showed that the aluminum electrodes were more efficient and as well as in a short period of time as 10min. Chemical oxygen demand and oil–grease removal values obtained as 64.8% and 57% from Al and 36.2% and 12.5% from Fe, respectively. On the other hand by electro-fenton process, it was seen that higher removal efficiencies were obtained in comparison to the electrocoagulation method, with the COD and oil–grease removal being equal to 71% and 69%, respectively. The discharge standards specified by MARPOL were obtained by the electro-fenton process. When processes are analyzed in economically way, the electricity cost of electrocoagulation process by aluminum, iron and electro-fenton process was 0.54$/m3, 0.53$/m3, 0.51$/m3, respectively. In addition, pseudo-second-order kinetic model was fitted for both COD and Oil&Grease removal in electrocoagulation process.

Construction and Testing of a radiation-beam powered TA (ThermoAcoustic) washer for grease removal

A small washer powered directly and solely by thermal radiation was constructed and tested to explore the feasibility of using solar energy or other types of thermal radiation for washing and cleaning. In principle, TA (ThermoAcoustic) washers have the benefits of simpler design and operation and fewer energy conversion processes, thus should be more energy efficient and cost less than electric washing/cleaning systems. The prototype TA converter we constructed could sustain itself with consistent fluid oscillations for more than 20 minutes when powered by either concentrated solar radiation or an IR (infrared) heater. The frequencies of water oscillations in the wash chamber ranged from 2.6 to 3.6 Hz. The overall conversion efficiency was lower than the typical efficiencies of TA engines. Change in water temperature had little effect on the oscillatory flow in the TA washer due to its low efficiency. On the other hand higher water temperatures enhanced grease removal considerably in our tests. Methods for measuring the overall conversion efficiency, frictional loss, and grease removal of the TA washing system we designed were developed and discussed.

Treatment of vegetable oil refinery wastewater by sorption of oil and grease onto regranulated cork – A study in batch and continuous mode

The feasibility of a novel sorption treatment using regranulated cork granules for oil and grease (O&G) removal from real vegetable oil refinery wastewaters (VORW) was investigated and compared to similar treatment of oil-in-water emulsions.O&G sorption from real VORW onto regranulated cork particles was studied at different pH and ionic strength conditions. Only wastewater acidification was able to effectively destabilize the O&G emulsion in the wastewater, enhancing the sorption process (efficiency over 80% at pH 2.0).A 3-factor, 3-level (33) Box–Behnken experimental design was used to examine the effect of pH, ionic strength and soap/oil ratio on O&G removal efficiency in oil-in-water emulsions. All effects were significant (p<0.05) when considered individually, but no significant interactions were observed. pH was found to have the strongest effect, supporting the initial observations in real VORW.The treatment of a simulated wastewater (60% soap/oil ratio, 0.2M NaCl and pH 2.0) was completed in batch and continuous mode. Freundlich and linear partitioning models were used to describe O&G sorption equilibria. Continuous treatment was successfully carried out in a stirred-tank reactor using a cork dosage of 3.4gL−1, a stirring speed of 250rpm and a flowrate of 10mLmin−1. The reactor was fed for 8h with simulated wastewater (205±30mgL−1 O&G) yielding an effluent with an O&G content below 15mgL−1 (discharge limit defined in Portuguese legislation). A mass transfer model was applied to describe the O&G sorption kinetics in batch and continuous stirred-tank reactors.

Fundamentals of mass transfer and kinetics for biosorption of oil and grease from agro-food industrial effluent by Serratia marcescens SA30

Biosorption mechanisms of oil and grease removal bySerratia marcescensSA30 from agro-food industrial effluent, attached on the oil palm frond.

Borate Free Cleaners for Aluminum Alloys

The paper analyzes four new borate-free aluminum alloys cleaners, designed for the removal of grease, ink or solid soils contaminating the surface of aluminum components before anodizing or painting stages. Different borate-free formulations (2 proposed by Italtecno MG19 NB2, MG19 NB3 and two available on the market) were tested and investigated evaluating the cleaning efficiency compared to formulation actually in use containing borates and also evaluating the impact in term of corrosion or damage of these new formulations on two different aluminium alloys used in aeronautical applications (2024 clad and unclad).

English

The production of biodiesel through the transesterification method produces a large amount of wastewater that contains a high level of chemical oxygen demand (COD) and oil and grease (O&G). In this study, coagulation was adopted to treat the biodiesel wastewater. Two types of coagulation were examined using a standard jar test apparatus, i.e. polyaluminium chloride (PAC) and aluminium sulphate. The effects of pH and coagulant dosage were examined at 150 rpm of rapid mixing and 20 rpm slow mixing and 30 min settling time. Higher removal of suspended solids (SS), colour, oil and grease (over 90%), and COD (over 80%) were achieved at pH 6. PAC was found to be superior to aluminium sulphate, yielding a lower amount of coagulation, i.e., 300 mg/L. The result indicated that the coagulation and flocculation process played bigger roles in the integrated treatment system.

Treatment of the petroleum refinery wastewater using combined electrochemical methods

This study explores the performance of electrochemical and combined oxidation methods for the treatment of petroleum refinery wastewater (PRW). The electrocoagulation operating parameters studied includes reaction time and applied voltage. In situ hydrogen peroxide treatments at different dosages and hybrid electrochemical systems (ECEO, ECS25, ECS33, ECEO + US33) have been studied. The efficacy of the treatment system has been evaluated in terms of reduction of phenols, COD, TOC, oil, and grease. The most effective method for PRW treatment is ECEO + US33 where the maximum % removal of phenols, TOC, COD, oil, and grease are reported to be 98, 92, 92, and 92%, respectively. The results demonstrate the technical feasibility of using hybrid electrochemical process as a possible and reliable methods for the treatment of PRW.

Nitrogen Removal to Minimize Energy Consumption of the Two WWTPs Choutrana II and Menzel Bourguiba in Tunisia

Abstract The control of the aeration time and the dissolved oxygen in a reactor plays an important role in the management of the plant and the reduction of energy consumption. For this, two full-scale municipal wastewater treatment plants were chosen. The first plant (Choutrana II) designed for 600,000 population-equivalents (p.e), consists of a primary treatment step (screening, grit and grease removal), followed by four parallel oxidation ditches with a total volume of 60,000 m3. Aeration is ensured by air diffuser. The second plant (Menzel Bourguiba) designed for 140,000 p.e consists of a primary treatment stage (screening, grit and grease removal), followed by anoxic tanks and two aerobic reactors with a total volume of 14,000 m3. Aeration is ensured by six surface aerators which are operated episodically to create aerobic and anoxic conditions. Currently, the aeration management is controlled by a timer with a maintained oxygen concentration at a given level in the aerobic reactor. The nitrogen removal is done during air-on and air-off periods. The process can be seen as a succession of aeration periods followed by an anoxic period. This category of plant operation is far from the optimal and raises energy consumption and operative costs. The purpose of this study is to implement a new strategy to control aeration taking into account the variation of the daily organic load received by plants (feedforward control) and to create favorable conditions for nitrification and denitrification steps (feedback control). The Activated Sludge Model 1, which is calibrated and validated by respirometry tests, is used. Simulation results show the potentialities of the chosen strategy, which could save 28% of aeration energy and could adjust the aerobic and anoxic times. As first results, daily aeration time could be considered enough to produce treated water conform to standard terms. For Choutrana II plant, the results obtained have allowed to achieve a nitrogen removal rate of 85% and an output concentration between 6 and 12 mg/L. Rates of nitrification and denitrification were estimated at 4 mg NO3-N/L/h and 6 mg NH4-N/L/h, respectively. At the same time, aeration periods (on/off) are connected with daily organic load received by the plant and created favorable conditions for nitrification–denitrification. A good agreement between input biological loads, aeration profile and nitrogen removal is approved.

Study on the Application of Water Jet Technology in Artillery Maintenance

To coat with much of lubricating grease is an effective approach to slow down the wearing and rusting trend of each mechanism, the lubricating grease must be removed before grease-change maintenance and overhauling of the artillery. At present, the grease removing methods mainly include physical heating, mechanical removal, chemical cleaning, etc. Comparing the advantages and disadvantages of various methods, this paper proposes to use the technology of a high-pressure water jet cleaning. This method overcomes the problems in the process of grease removal.