Suspended Oil Research Articles

Characterizations of Some Selected Clay Types for Cost Effective Wastewater Treatments

Water pollution poses a significant challenge to water consumption, particularly in relation to drinking purposes. Various factors such as industrial discharge, improper waste management, waste build-up, and natural activities contribute to the contamination of water bodies. Adequate water treatment plays a crucial role in the preservation of water quality and compliance with environmental regulations. The treatment process typically involves the application of physical, chemical, and biological techniques, with a common reliance on chemical substances and intricate systems. Recent studies have increasingly explored the utilization of cost-efficient natural materials for water treatment, highlighting benefits like affordability, user-friendliness, health advantages, and widespread availability. This particular investigation aimed to assess the suitability of selected natural substances for the treatment of wastewater, focusing primarily on methods like adsorption, absorption, and filtration. A number of earth materials, notably three distinct types of clays prevalent in Sri Lanka, were singled out for examination. The findings unveiled that these clays predominantly consist of over 75% iron in their mineral composition, with certain samples displaying finer particles to enhance porosity and permeability. These raw materials exhibit potential for the fabrication of wastewater treatment systems intended for the elimination of suspended particles, dissolved solids, heavy metals, pathogens, oils, and toxic compounds. Their distinct chemical properties render them appropriate for catalytic reactions and advanced chemical processes

Risk assessment through feature, event, and process for repurposing suspended oil and gas wells for geothermal purposes

Many countries have set the goal of net zero carbon emission and are diverting their energy source towards renewables. In that respect, geothermal energy is a continuous renewable energy source that is not affected by any metrological conditions. However, geothermal energy is not used to its full potential, and at present, less than 1 % of renewable energy is produced by geothermal sources. One of the biggest reasons that hinder its adoption is the cost of drilling and completion associated with the geothermal well, which almost takes 50 % of the project budget. Therefore, it is important that, where possible (with conducive geothermal conditions), conventional oil and gas wells that are old or temporarily suspended should be retrofitted into geothermal wells. In this way, the initial cost of the geothermal project can be reduced, which is mainly due to the drilling operations. However, before repurposing old retired wells, conducting a proper risk assessment is important to avoid any well integrity issues in the long run. Therefore, this paper presents a concept of accessing the risk using Feature, Event, and Process (FEP) that have been integrated with the interaction matrix, incident potential matrix (IPM), and cause-effect plot diagram. This risk assessment technique identifies the well components that might be susceptible to failure, and remedial work should be conducted on such elements. However, geothermal wells have no specific FEPs; hence, the FEPs from CCS wells have been used, which have their limitation when used for geothermal systems. Nonetheless, to show the feasibility of this approach in assessing the risk, two case studies of the fictitious tubingless geothermal well are presented in this paper.

Comparative analysis of water quality index and river classification in Kereh River, Penang, Malaysia: Impact of untreated swine wastewater from Kampung Selamat pig farms.

The Kereh River in Penang, Malaysia, has faced severe pollution for over 40 years due to untreated wastewater from swine farms in Kampung Selamat, discharged via stormwater drains. Despite official claims that all 77 swine farms treat their wastewater to meet regulatory standards, local non-governmental organizations and villagers have challenged this, though their concerns lack scientific backing. This study evaluates the river's water quality by analyzing samples from upstream (US), midstream (MS), and downstream (DS), and from Parit Cina-Parit Besar, a conduit for untreated swine wastewater. Fourteen parameters were measured against Malaysia's National Water Quality Standards (NWQS). Significant differences were found in six parameters: ammonium nitrogen (AN), biochemical oxygen demand (BOD), chemical oxygen demand (COD), dissolved oxygen (DO), total suspended solids (TSS), and oil and grease (OG). While Dunn's post hoc pairwise comparison showed no significant differences among river segments, mean values indicated increased pollution downstream, particularly after the convergence with untreated swine wastewater. River classification worsened, with water quality index dropping from 69.88 ± 11.37 score (Class III) US to 38.49 ± 12.74 and 50.44 ± 3.14 scores (Class IV) MS and downstream, respectively. A significant positive correlation between E. coli and AN (r = 0.71, p < 0.01) suggests a common point source pollutant, particularly the untreated swine wastewater. The river exhibits low oxygen levels and high organic matter and nutrient concentrations, especially MS and downstream, highlighting substantial ecological and public health risks. Effective enforcement of waste treatment regulations and enhanced monitoring are crucial for mitigating pollution and restoring the river's ecosystem. Collaboration between authorities and pig farmers is essential to improve water quality and maintain the river's ecological balance. PRACTITIONER POINTS: Severe Kereh River pollution: Untreated swine wastewater from Kampung Selamat pig farms, primarily via Parit Cina-Parit Besar, has degraded the river for over 40 years. Regulatory non-compliance: Despite official claims, untreated swine wastewater continues to pollute the river, challenging regulatory standards. Significant pollution indicators: Elevated levels of AN, BOD, COD, DO, TSS, OG, and E. coli signal severe pollution midstream and downstream. Water quality index drop: WQI scores classify midstream and downstream sections as polluted, indicating worsening conditions downstream. Urgent need for action: Enforcing regulations, improving wastewater treatment, and relocating pig farms are crucial for restoring the Kereh River.

A digital image analysis approach to understand the microscopic and macroscopic phenomena in dissolved air flotation

Dissolved air flotation (DAF) is an effective method for separating suspended oil and solid particles from wastewater by utilizing small air bubbles. This study aims to investigate the impact of key factors, such as saturating pressure and water flow rate, on the separation of fine oil droplets from a water stream. The macroscopic flow patterns within the cell were analyzed using particle image velocimetry (PIV), while Digital Image Analysis (DIA) was employed to study microscopic phenomena, including oil droplet rising velocity and oil-bubble contact mechanisms. Our findings propose a safe operating window (specifically, water flow rate and saturation pressure) for the effective separation of oil droplets without any oil escaping into the clean water stream. It was found that the oil droplet rising velocity increases with the saturation pressure up to 200 kPa. However, a further increase in the pressure of the air saturating chamber leads to a decrease in oil droplet rising velocity. Additionally, we identified a peak in rising velocity at an oil droplet size of approximately 200 µm. Below this threshold, the rising velocity increases with droplet size, while for droplet sizes exceeding 200 µm, the rising velocity decreases with size. This behavior can be explained by the conflicting effects of droplet size increment according to the Stokes law for the rising velocity of oil droplets. As the droplet size increases, the average density of the bubbles/droplet aggregate rises, reducing the ∆ρ in the Stokes law and subsequently lowering the aggregate rising rate. However, as per the Stokes law, the oil droplet rising velocity increases proportionally to the square of its size.

Assessment of Changes in Water Quality of Enim River, Muara Enim, South Sumatera, Indonesia to Determine Environmental Designations

Enim river flows within several sub-districts in Muara Enim Regency, including Semendo Darat Laut, Semendo Darat Tengah, Semendo Darat Ulu, Tanjung Agung, Lawang Kidul, and Muara Enim. This study examines changes in the water quality of the Enim River due to domestic wastewater discharges and the presence of the coal mining industry and household industries. Water samples were taken from 4 sampling stations along the Enim River in 2018 and 2023. Data consisted of results of physical, chemical, and microbiological parameters. The status of river water quality was assessed from the pollution index. The results of Enim River surface water quality measurements showed that the parameters of total suspended solids, Dissolved Oxygen, iron (Fe), copper (Cu), oil, and grease concentrations had breached the criteria set for Class II water quality, referring to Government Regulation of the Republic of Indonesia Number 82 of 2001. The results showed that there has been a change in the water quality status of Enim River from 2018 to 2023. The river water pollution index was (1.43-2.47) in 2018 and (1.49-3.85) in 2023 (lightly polluted). Comprehensive water treatment and preventive measures are necessary to manage and mitigate additional pollution in the Enim River.

Analysis of Environmental Impacts of Tuz gölü Natural Gas Storage Project on Tuz Lake

Tuz Gölü Natural Gas Storage Project is one of the most crucial projects developed by BOTAŞ within the framework of ensuring energy supply security. Within the scope of this project, artificial caverns are created for the storage of natural gas and for this purpose, salt layers located 700 to 1500 meters below the ground are leached with fresh water. The brine released as a result of the leaching is discharged into the Tuz Gölü through a 40 km pipeline. This study aims to analyze and interpret the effects of this discharge on the Tuz Gölü. pH, Electrical Conductivity, Salinity, Dissolved Solids Suspended Solids, Sulfate, Chloride Alkalinity, Nitrate, Nitrite, Ammonium Nitrogen, Sodium, Magnesium, Calcium, Oil and Gress parameters were analyzed to determine the water quality in the brine samples taken monthly from the brine discharge point from 2015 when the discharge started until 2023. Related measurements were taken monthly within the scope of this project and analyzed by an accredited laboratory. SPSS 25.0 for Windows package program was used for data analysis. Mean and standard deviation values were used to describe the data. Kolmogorov Smirnov normality test was performed to confirm conformity of the research parameters to the standard normal distribution. The present study aims to provide an environmental impact prediction for future projects.

Pemanfaatan Magnetic Biochar dari Cangkang Sawit Sebagai Adsorben untuk Menyisihkan COD, Total Suspended Solid, Minyak dan Lemak dalam Air Buangan Domestik

Greywater is wastewater from domestic activities sourced from kitchens, bathrooms, and laundry water. Greywater discharged directly into the environment can cause a decrease in surface water quality due to its high organic content, nutrients, pathogenic bacteria, and detergents and surfactants. One method that can be used to remove organic and nutrient content is adsorption. The success of the adsorption process is determined by several factors, such as adsorbent type, dosage, contact time, and others. One adsorbent that has attracted the attention of many researchers in recent years is magnetic biochar. This study aims to remove chemical oxygen demand (COD), total suspended solids (TSS), oil, and grease from greywater with a magnetic biochar adsorbent made from palm shells. The study was conducted by varying the dose of 1.2–8.55 g/l and the contact time of 30–150 minutes. The results showed that increasing the dose and contact time can increase the removal efficiency of COD, TSS, oil, and grease. The best results were obtained at a dose of 8.55 g/l and a contact time of 150 minutes. The removal of COD, TSS, oil, and grease was 87.91%, 88.46%, and 99.96%, respectively.

Dynamics of a Water Droplet Impacting an Ultrathin Layer of Oil Suspended on a Pool of Water

This study investigates water droplets impacting a two-layered pool, consisting of a deep pool of water above which an ultrathin a suspended layer of silicone oil is present. Initially, the difference between the impact dynamics of water droplets on ultrathin and thick layers of oil were studied. It was found that the existence of an ultrathin layer of oil changes the impact characteristics such how aggressively the jet rises, how the dimensions of the impact impression change, and how the jets are broken down on their tops. Then, in a series of experiments on ultrathin layers of oil, the droplet size, the velocity of the droplets upon impact, and the viscosity of the oil layers were changed to observe and measure the characteristic dimensions of the formed craters and the jets. It was observed that when the viscosity of oil layers decreased to a minimum of 1 (cSt), the jet height and crater sizes increased to their maximum value. In addition to the effect of the oil viscosity, it was found that the droplet size and the release heights of the droplets were in the next orders of significance in determining the impact dynamics. The impacts were also characterized qualitatively by specifically looking into the crown and crater formations, pinch-off modes in jets, and number of formed secondary droplets. As well as the quantitative conclusion, it was found that the major affecting parameter in changing each of these qualities was the viscosity of the suspended oil layer.

Selective separation characteristics and mechanism of oil substances with different occurrence states in coal chemical wastewater

In response to the complex nature of oil substances in coal chemical wastewater (CCW), and the challenges they pose in separation and removal, this study conducted a detailed analysis of the occurrence, composition, and content of oil substances in CCW. The selective separation characteristics and mechanisms of various materials for oil substances in different occurrence states were explored. The results revealed four main states of oil substances in CCW: suspended oil, dispersed oil, emulsified oil, and dissolved oil, with respective contented of 37.17 %, 27.82 %, 17.79 %, and 17.22 %. These oil substances primarily consisted of alkanes, aromatic hydrocarbons, benzene series, and phenolic compounds, with a total concentration of 2942.18 mg/L. Based on the investigation of the characteristics of oil substances and relevant characterization analyses, the study further explored the selective separation characteristics and mechanisms of different materials for oil substances in various occurrence states. The results indicated that activated carbon, resin, fiber balls, and oil-absorbing felt exhibited excellent selective removal efficiency for dissolved oil, emulsified oil, suspended oil, and dispersed oil, with removal rates of 79.28 %, 63.33 %, 66.89 %, and 55.54 %, respectively. These findings provide theoretical support for the selective separation and recovery of oil substances in CCW, showcasing significant practical applications.

Assessment of the potentials of Autochthonous lipase-producing bacteria in the treatment of palm oil mill effluent

Pollution caused by the release of untreated palm oil mill effluent (POME) is a major environmental concern. This research assessed the potentials of single and consortium ofautochthonous lipase-producing bacteria as a non-invasive procedure in the biotreatment ofPOME. The identity of lipase-producing bacteria in POME were determined using morphological and biochemical techniques. Identified isolates were monitored for POME utilization by measurement of optical density at 600 nm in 25 ml Bushnell Haas broth supplemented with 0.25 ml sterilized POME. Individual isolates and consortium were then used for the bioremediation of POME. Quality parameters including pH, total suspended solid (TSS), oil and grease, chemical oxygen demand (COD), biological oxygen demand (BOD), total organic carbon (TOC), total organic matter (TOM) and total nitrogen (TN) of the raw and treated effluents were evaluated. The population (CFU/ml) of total heterotrophic, POME - utilizing and lipolytic bacteria were 3.9 x 106, 2.8 x 106 and 3.5 x 105 respectively. The lipolytic bacterial isolates include Brenneria nigrifluens, Bacillus circulans and Paenibacillus pectinilyticus. Results revealed varying pH of 5.03 and 6.81 - 7.26 for untreated and treated respectively. The lipolytic bacteria from POME caused reduction efficiency of 100% in TSS and oil and grease contents of the treated effluents relative to the raw samples. The COD, BOD, TOC, TOM and TN reduction ranged 17.90 - 93.55, 1.66 - 90.52, 16.34 - 59.79 %, 6.18 - 80.78 % and 11.71 - 93.66 % respectively. This research indicated that POME indigenous lipase-producing bacteria improved POME quality and therefore suggestive of their potentials in the bioremediation of POME-contaminated environment with the consortium being most effective.

Potentials of Aquatic Plants in the Treatment of Paint Industry Effluent: A review

Nigeria's population has increased dramatically in recent years, leading to massive urbanization and industrialization with a concomitant increase in environmental pollution. Chemical industries such as the paint industry use large quantities of water in their processes, resulting in the generation and release of a lot of effluent into the environment. These effluents contain suspended solids, pigments, colorants, heavy metals, oil, and grease, which, if not properly managed, could have a negative impact on the environment and human health. Therefore, the purpose of this paper is to review the effectiveness of the various conventional methods of treating paint effluent as compared to phytoremediation.

Innovative Approaches to Poultry Processing Wastewater Treatment: The Stainless Steel Ultrafiltration Membrane as a Viable Option.

In pursuit of sustainability, we explored replacing conventional dissolved air floatation (DAF) in poultry processing wastewater (PPW) treatment with a precisely tuned 0.02 µm stainless-steel ultrafiltration (SSUF) membrane. SSUF is a robust, homogenously porous membrane with strong chemical resistance, ease of cleaning, and exceptional resistance to organic fouling. Unlike polymeric membranes, it can be regenerated multiple times, making it a cost-effective choice due to its compatibility with harsh chemical cleaning. The PPW used for the study was untreated wastewater from all processing units and post-initial screening. Our study revealed the SSUF membrane's exceptional efficiency at eliminating contaminants. It achieved an impressive removal rate of up to 99.9% for total suspended solids (TSS), oil, grease, E. coli, and coliform. Additionally, it displayed a notable reduction in chemical oxygen demand (COD), biochemical oxygen demand (BOD), and total Kjeldahl nitrogen (TKN), up to 90%, 76%, and 76%, respectively. Our investigation further emphasized the SSUF membrane's ability in pathogen removal, affirming its capacity to effectively eradicate up to 99.99% of E. coli and coliform. The measured critical flux of the membrane was 48 Lm-2h-1 at 38 kPa pressure and 1.90 m/s cross-flow velocity. In summary, our study highlights the considerable potential of the SSUF membrane. Its robust performance treating PPW offers a promising avenue for reducing its environmental impact and advocating for sustainable wastewater management practices.

Integrated Process of Immediate One-Step Lime Precipitation, Atmospheric Carbonation, Constructed Wetlands, or Adsorption for Industrial Wastewater Treatment: A Review

The transition from the linear economy paradigm to the circular economy in industrial wastewater treatment systems is on the global agenda. The search for new simple, eco-innovative, and low-cost processes for treating industrial wastewater, which can also be used by small and medium-sized industries, has been a constant challenge especially when environmental sustainability is considered. So, a new integrated industrial wastewater treatment system has been developed that includes the immediate one-step lime precipitation process (IOSLM) and atmospheric carbonation (AC), followed by constructed wetlands (CWs) or adsorption. The current review provides an overview of industrial wastewater treatment strategies for high- and low-biodegradable wastewater. A background on functionality, applicability, advantages and disadvantages, operating variables, removal mechanisms, main challenges, and recent advances are carried out for each process that makes up the IOSLM+AC+CW/adsorption integrated system. The prospects of the IOSLM+AC+CW/adsorption integrated system are also discussed. Not neglecting the improvements that still need to be made in the integrated treatment system as well as its application to various types of industrial wastewater, this review highlights that this treatment system is promising in industrial wastewater treatment and consequent by-product recovery. The IOSLM+AC integrated system showed that it can remove high amounts of organic matter, total suspended solids, oils and fats, phosphorus, and ammonium nitrogen from industrial effluents. On the other hand, constructed wetlands/adsorption can be alternatives for refining effluents still containing organic matter and nitrogen that were not possible to remove in the previous steps.

Field investigation of the transport and attenuation of fugitive methane in shallow groundwater around an oil and gas well with gas migration

‘Fugitive’ or ‘stray’ gas migration from deeper formations due to well bore integrity failure has prompted concern regarding environmental impacts. Unintended methane (CH4) migration can increase greenhouse gas emissions and affect groundwater quality in the critical zone. Although the CH4 transport in shallow aquifers has been investigated at experimental injection sites, no intensive groundwater studies have been published around an oil and gas well that has been leaking for a significant period of time. In this field study, groundwater samples were collected from sixteen groundwater monitoring wells (1.25 m below ground surface) installed around a suspended oil and gas well with decadal scale gas migration (estimated ~0.2 m3/day). Stray CH4 distribution and preferential pathways in the shallow groundwater zone were evaluated though high-resolution profiling of equivalent concentrations of hydrocarbon gases (C1-C6; >85 % CH4 at the study site) and bulk formation electrical conductivity to 6.0 m below ground surface. The highest dissolved CH4 concentration (0.074 mmol/L or 1.18 mg/L) in groundwater (1.25 m bgs) was observed immediately downgradient (1.25 m) of the oil and gas well head. Similarly, high-resolution profiling data also revealed the occurrence of relatively high CH4 concentrations in shallow groundwater along the groundwater flow direction and below fine-grained layers up to 10 m distance from the well head. Microbial DNA analysis from groundwater showed significant community shifts, with the highest relative abundance and diversity of methanotrophs observed in the vicinity of the oil and gas well. This study supports findings from experimental injection and laboratory studies, which also found that significant CH4 transport i) dominantly occurs in the groundwater flow direction, and ii) laterally as free phase below fine-grained layers. The occurrence of CH4 concentrations below saturation after more than two decades of gas migration suggests limited impacts have occurred in the shallow subsurface investigated.

Impact of mixing energy and dispersant dosage on oil dispersion and sedimentation with microplastics in the marine environment

Recently, the fate of spilled oil in the presence of microplastics (MPs) in the sea has attracted attention of researchers. Merey crude oil and polyethylene terephthalate (PET) were used as the experimental materials in this study. The effects of mixing energy and dispersant dosage on oil dispersion and sedimentation in the presence of MPs in the water column were investigated by laboratory experiments simulating actual sea conditions. The increase of mixing energy showed a promoting effect on oil dispersion. When the oscillation frequency increased from 140 rpm to 180 rpm, the oil dispersion efficiency (ODE) ranged from 2.1 %–3.7 % to 17.4 %–30.8 %, and the volumetric mean diameter (VMD) of the suspended oil droplets/MPs-oil agglomerates (MOA) decreased from 99.9–131.4 μm to 76.6–88.2 μm after 2 h oscillation. The application of chemical dispersant led to an increase in both the quantity and size of the formed sunken MPs-oil-dispersant agglomerates (MODA). At the dispersant-to-oil ratio (DOR) of 1:5, the ODE declined from 77.7 % to 62.6 % when the MPs concentration increased from 0 to 150 mg/L, while the oil sinking efficiency (OSE) rose from 3.4 % to 15.6 % when the MPs increased from 25 to 150 mg/L; the maximum size of the sunken MODA reached 13.0 mm, and the total volume of the MODA formed per unit volume oil reached 389.7 μL/mL oil at the MPs concentration of 150 mg/L. Meanwhile, the results showed that the presence of MPs inhibited the oil dispersion by increasing the oil-water interfacial tension. The outcomes of this work may provide assistance in predicting the transport of spilled oil and developing emergency measures.

Experimental study on the effect of tight gas fracturing flowback fluid composition on the performance of modified polyacrylamide viscosity reducing and slippery water system

AbstractTight gas belongs to unconventional gas reservoirs, and to obtain high gas production, it needs to be fractured and reformed. After the construction is completed, a large amount of flowback fluid is produced. In order to reduce the cost of flowback fluid treatment and avoid environmental pollution, a slippery water system with flowback fluid is usually used on the site of hydraulic fracturing. Almost all flowback fluids contain high‐order cations such as calcium ions, magnesium ions, iron ions, and a large amount of suspended solids. Some flowback fluids contain incomplete gel‐breaking micelles and unseparated condensate oil. The performance of the viscosity‐reducing and slippery water system with flowback fluid as the base fluid is poor, usually manifested as low viscosity of the slippery water, low friction reduction rate, and high formation damage. To study the effect of tight gas fracturing flowback fluid on the performance of modified polyacrylamide viscosity‐reducing and slippery water system, this paper found through cryo‐electron microscopy scanning experiments that the flowback fluid made the modified polyacrylamide molecular chain unable to form a complex network structure and showed the phenomenon of reduced strength and aggregation. The effects of mineralization degree, calcium and magnesium ions, divalent and trivalent iron ions, suspended solids, pH value, and oil content on the viscosity, friction reduction performance, and rock damage of the viscosity‐reducing and slippery water system were analyzed experimentally. It was found that the viscosity of the viscosity‐reducing and slippery water system was mainly affected by divalent iron ions, calcium and magnesium ions and other divalent cations; the friction reduction rate was mainly affected by the content of suspended solids and oil content; and the rock damage was mainly affected by the pH value and the content of suspended solids. Based on this, recommended parameters for reusing tight gas fracturing flowback fluid are given to guide the smooth progress of hydraulic fracturing construction on‐site.

Molecular dynamics simulation of oily wastewater treatment by air floatation

Molecular dynamics (MD) method was used to study the process of treating oily wastewater by air flotation. The bubbles generated by the machine combine the suspended oil droplets in the oily wastewater in the way of entrapment. In the process of upward movement, bubbles will collide with oil droplets suspended in water, the oil droplets will slightly deform on the surface of foam film, and the oil droplets will stick to the surface of foam film. Moreover, in the process of oil droplets floating up with bubbles, the foam film will further depress the position of oil droplets to the gas phase, and the closer oil droplets will coalesce in the depression, while the farther oil droplets will approach each other without coalescence.

Biomass Fuel Production through Fermentation of Lysinibacillus sp. LC 556247 in Various Ratios of Palm Oil Mill Effluent and Empty Fruit Bunch

Biomass wastes originating from palm oil milling activities can be characterized by their high biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solid (TSS), and oil and grease content. The utilization of oil palm wastes such as palm oil mill effluent (POME) and empty fruit bunch (EFB) has great potential for a sustainable energy biomass pellet as it reduces the reliance on conventional materials for energy production. A mixture of POME and EFB in various ratios ranging between 7:3, 8:2, 9:1, and 10:0 was fermented in the presence of Lysinibacillus sp. LC 556247 for 120 h at 37 ± 2 °C and 180 rpm with the aim of elucidating the biodegradation of complex organic material in terms of BOD, COD, TSS, total organic carbon, inorganic carbon, and total carbon content. After fermentation, the mixtures were oven dried at 105 °C overnight and then subjected to calorific energy value (CEV) determination. The highest CEV of 20.26 MJ/kg was achieved for a ratio of 10:0 (slightly higher than the control experiment with the value of 18.67 MJ/kg), with maximum removal efficiencies of COD (12.19%), BOD (11.72%), TSS (93.94%), and oil reduction of 17.43%. The addition of EFB did not positively increase the CEV.

Treatment of Industrial Saline Wastewater Using Eco-Friendly Adsorbents

The wastewater generated from the oil and gas sector is one of the major environmental issues. Varieties of techniques are employed for the treatment of generated wastewater. In this work, an attempt has been made to treat industrial saline wastewater from the oil and gas industry using a combination of synthesized biopolymer, chitosan, with graphene. Chitosan has been synthesized from a bioresource using marine spent. Chitosan was characterized using field emission scanning electron microscopy (FE-SEM), Fourier transform infrared (FT-IR) spectroscopy, energy dispersive X-ray (EDX) spectroscopy, and thermogravimetric analysis (TGA). Batch experiments were conducted by varying the composition of graphene viz 1, 2, 3, 4, and 5 w/w with respect to a fixed amount of chitosan. The percentage removal efficiency of chemical oxygen demand (COD), total dissolved solids (TDS), total suspended solids (TSS), turbidity, and oil and grease were evaluated. A combination of chitosan and graphene has effectively removed the pollutants present in oil produced water (OPW) compared to chitosan alone. The maximum percentage removal efficiencies of COD (84%), TDS (91%), TSS (80%), turbidity (95%), and oil and grease (99.9%) were obtained for a mixture of chitosan (0.5 g/100 mL) and 5 wt% graphenes. The Freundlich equilibrium isotherm model suited the adsorption data well.

Stormwater treatment using an ultrafiltration membrane and pulsatile fluid flow

ABSTRACT A polymeric ultrafiltration (UF) membrane was used for stormwater treatment, with the focus on evaluating the increase in the membrane process productivity by adding pulsatile fluid flow to UF membrane treatment. Sedimentation and sieving were used as pre-treatment. The result showed that increasing the pulse frequency from 0 to 4 Hz increased productivity from −6.6 to 82 LMH. UF membrane removed suspended solids, oil and turbidity below detection limit. The UF membrane also separated total coliforms, E. coli and P. aeruginosa below detection limit. Total organic carbon (TOC) was reduced by between 81%, in average. In addition, the UF membrane was able to reduce BOD7 and COD to below 7 mg/L in the permeate. According to the US EPA, WHO, and national regulations in Canada, Japan, and South Korea, treated stormwater can be used for flushing toilets and streets irrigation and agricultural use.