Chemical Oxygen Demand Levels Research Articles

The effectiveness of using coconut husk powder as an adsorbent to enhance the wastewater quality of the cepuk textile industry in Nusa Penida, Bali, Indonesia

Introduction: Tenun Cepuk (traditional woven) from Nusa Penida holds great potential as a traditional textile art form, cherished for its intricate patterns and cultural significance. However, the textile industry's wastewater, with its dye-related pollution, presents a significant environmental challenge that needs sustainable solutions. Coconut husk powder exhibits promising potential as an adsorbent for treating dye wastewater from the textile industry. Investigating the interplay between varying thicknesses and contact durations is crucial to maximizing coconut husk powder's adsorption capacity and efficiency for dye wastewater treatment. Method: This study, following an Experimental research design with a Posttest Only Control Group Design, aims to assess the impact of an intervention on the experimental group compared to the control group. Coconut fibers, sourced from Nusa Penida agriculture, serve as the adsorbent. Coconut powder is added to these tanks at thicknesses of 5 cm, 10 cm, and 15 cm. Subsequently, wastewater samples from the Cepuk weaving process are introduced into each experimental tank, along with a control group. The process is left for 24 and 72 hours as varying contact times. The adsorption results are subjected to analysis for parameters, including total suspended solids (TSS), total dissolved solids (TDS), five-day biochemical oxygen demand (BOD5), and chemical oxygen demand (COD) at the Panureksa Denpasar Laboratory. Results: The use of coconut husk powder as an adsorbent effectively lowers TDS, TSS, BOD5, and COD in Cepuk textile dye wastewater. The reduction depends on adsorbent thickness and contact time. Thicker adsorbents notably reduce TDS, TSS, BOD5, and COD, enhancing wastewater quality and environmental safety. A 15 cm-thick adsorbent effectively reduces TDS to permissible levels. Prolonged contact times also significantly lower levels. Conclusion: Coconut husk powder can be utilized to decrease TDS, TSS, BOD5, and COD levels in textile dye wastewater. Thickness and contact time significantly impact the enhancement of wastewater quality.

Identification of freshwater microbiota and physicochemical analysis of water Waduk Lhok Batee Jeumpa

Biota components can provide an overview of the physical, chemical and biological conditions of a waters. One biota that can be used as a biological parameter in determining the condition of a waters is biota. Changes in the quality of water and its living substrate greatly affect the abundance and diversity of biota. The aim of this study was to identify fresh water microbiota and physicochemical analysis of water in the Lhok Batee Jeumpa Reservoir. The research method used is a combination of qualitative and quantitative research. Based on the research results, there are 13 types of Plankton consisting of 12 families in the Lhok Batee Reservoir. Plankton diversity is included in the low category with a diversity index of 0.4296. Dissolved Oxygen (DO) levels obtained the lowest value in sample 2-A of 4.70 mg/L and the highest value in samples 1-B, 4-B and 5-A of 5.20 mg/L, according to the standard quality Class 2 (4 mg/L). Biochemical Oxygen Demand (BOD) levels obtained the lowest value in sample 5-A of 1.00 mg/L and the highest value in sample 3-A of 12.50 mg/L, in accordance with Class 2 quality standards (3 mg/ L). Chemical Oxygen Demand (COD) levels obtained the lowest value in sample 1-B of 20.22 mg/L and the highest value in sample 5-B of 84.76 mg/L, according to Class 2 quality standards (25 mg/L).

Fischer Tropsch Synthesis Wastewater Treatment Study using DW SIM

This project focuses on utilizing DWSIM to treat wastewater from the Fisher Tropsch Process. A well-known technique for transforming synthesis gas, a combination of carbon monoxide and hydrogen, into liquid hydrocarbons is the Fischer-Tropsch process. However, this procedure creates wastewater, which if not adequately treated, includes a variety of chemicals that can be detrimental to aquatic life. To get rid of these contaminants and satisfy regulatory standards, the Fischer-Tropsch process requires water treatment. The most often employed therapeutic modalities are physical, pharmacological, and biological therapies. In order to maintain the Fischer-Tropsch process' sustainability and environmental friendliness, efficient and effective water treatment is essential. The Fischer-Tropsch process can continue to be an effective way to make liquid hydrocarbons while minimizing its negative effects on aquatic habitats with the right water treatment. As a result, the goal of this research is to examine the treatment process, determine the chemical oxygen demand (COD) level of Fischer Tropsch water obtained by distillation, reduce its concentration, and prepare the water for neutralization.

Biodegradation of pyrene by bacterial consortia: Impact of natural surfactants and iron oxide nanoparticles

Polycyclic aromatic hydrocarbons (PAHs) are potentially hazardous compounds that could cause a severe impact on many ecosystems. They are very challenging to remove using conventional methods due to their hydrophobic nature. However, this issue can be resolved by utilizing surface-active molecules to increase their bioavailability. In this study, pyrene was chosen as the PAH compound to explore its degradability by the effect of individual bacterial strains (Pseudomonas stutzeri NA3 and Acinetobacter baumannii MN3) and mixed consortia (MC) along with natural surfactant derived from Sapindus mukorossi and iron oxide nanoparticles (NPs). Additionally, fatty acids esters, dipeptides, and sugar derivative groups were identified as potent bioactive components of natural surfactants. Various techniques, such as XRD, VSM, TEM, and FE-SEM with EDX, were utilized to characterize the pristine and Fenton-treated iron oxide NPs. The analytical results confirmed that the Fe3O4 crystal phase and spherical-shaped NPs exhibited excellent magnetic properties. The impact of natural surfactants and iron oxide NPs has significantly contributed to the biodegradation process, resulting in a prominent decrease in chemical oxygen demand (COD) levels. Gas chromatography-mass spectrometry (GC-MS) analysis showed that biodegradation systems produced primary hydrocarbon intermediates, which underwent oxidative degradation through Fenton treatment. Interestingly, synthesized iron oxide NPs effectively produced hydroxyl radical (•OH) during the Fenton reaction, which was confirmed by electron paramagnetic resonance (EPR) spectra, and the pristine iron oxide NPs underwent a material transformation observed. The study demonstrated an integrated approach for biodegradation and the Fenton reaction process to enhance the pyrene degradation efficiency (90%) compared to other systems. Using natural surfactants and iron oxide NPs in aquatic environments serves as a crucial platform at the interface of microorganisms and contaminated oil products. This interaction offers a promising solution for PAHs bioremediation.

Energy balance survey for the design and auto-thermal thermophilic aerobic digestion of algal-based membrane bioreactor for Landfill Leachate Treatment(under organic loading rates): Experimental and simulation-based ANN and NSGA-II

Although algal-based membrane bioreactors (AMBRs) have been demonstrated to be effective in treating wastewater (landfill leachate), there needs to be more research into the effectiveness of these systems. This study aims to determine whether AMBR is effective in treating landfill leachate with hydraulic retention times (HRTs) of 8, 12, 14, 16, 21, and 24 h to maximize AMBR's energy efficiency, microalgal biomass production, and removal efficiency using artificial neural network (ANN) models. Experimental results and simulations indicate that biomass production in bioreactors depends heavily on HRT. A decrease in HRT increases algal (Chlorella vulgaris) biomass productivity. Results also showed that 80% of chemical oxygen demand (COD) was removed from algal biomass by bioreactors. To determine the most efficient way to process the features as mentioned above, nondominated sorting genetic algorithm II (NSGA-II) techniques were applied. A mesophilic, suspended-thermophilic, and attached-thermophilic organic loading rate (OLR) of 1.28, 1.06, and 2 kg/m3/day was obtained for each method. Compared to suspended-thermophilic growth (3.43 kg/m3.day) and mesophilic growth (1.28 kg/m3.day), attached-thermophilic growth has a critical loading rate of 10.5 kg/m3.day. An energy audit and an assessment of the system's auto-thermality were performed at the end of the calculation using the Monod equation for biomass production rate (Y) and bacteria death constant (Kd). According to the results, a high removal level of COD (at least 4000 mg COD/liter) leads to auto-thermality.

Chitosan-modified cotton fiber: An efficient and reusable adsorbent in removal of harmful cyanobacteria, Microcystis aeruginosa from aqueous phases

In the present study, to remove harmful cyanobacterial species Microcystis aeruginosa from aqueous phases, adsorption-based strategy was utilized. For this strategy, the surface of cotton fiber was modified using chitosan molecules to develop a highly efficient and ecofriendly adsorbent in removal of Microcystis aeruginosa from aqueous solution. The pristine cotton fiber could not remove M. aeruginosa, while the chitosan-modified cotton (CS-m-Cotton) showed the 95% of cell removal efficiency within 12 h. The surface characteristics of chitosan-modified cotton compared to the pristine cotton fiber was examined by various surface analysis methods. In addition, the pre-treatment of pristine cotton using sodium hydroxide solution was an important factor for enhancement of chitosan modification efficiency on the cotton fiber. The developed chitosan-modified cotton fiber could be reusable for M. aeruginosa cell removal after the simple desorption treatment using ultrasonication in alkaline solution. During the repeated adsorbent regeneration and reuse, the chitosan-modified cotton maintained its M. aeruginosa removal efficiencies (>90%). From the acute toxicity assessment using the chitosan-modified cotton and, the measurements of chemical oxygen demand and microcystin level changes in the M. aeruginosa treatment process using the adsorbent, the environmental safety of the adsorption strategy using the developed adsorbent could be confirmed. Based on our results, the chitosan-modified cotton fiber could be proposed as an efficient and ecofriendly solution for remediation of harmful cyanobacterial species occurring water resources.

Application of combined hydrodynamic cavitation and Fenton reagent for COD reduction of cellulosic fiber industry effluents

The present work demonstrates the implementation of combined approach of hydrodynamic cavitation reactor and Fenton oxidation process for the treatment of three cellulosic fiber (CF) industry effluent streams using pilot scale reactor with operation at 500 L developed at an industrial site. In order to assess the techno-economic viability of the combined hydrodynamic cavitation (HC) and Fenton oxidation process, various sets of experimental runs were carried out. Effect of type of treatment approach, one step and stepwise addition of oxidants, number of cavitation passes, and finally the type of effluent varying in terms of initial chemical oxygen demand (COD) on the efficacy of treatment were studied. Based on the results, HC + Fenton oxidation scheme was demonstrated to be a viable option for the treatment of CF industry effluent streams. HC + Fenton treatment rapidly reduced COD, achieving almost 90 % reduction in just 10 min, highlighting its efficiency in industrial wastewater treatment. The treatment achieved substantial reduction in residual COD levels with actual value as up to 1000 mg/L COD in effluent-I, up to 150 mg/L COD in effluent-II, and up to 100 mg/L COD in effluent-III. The study also explored the operating cost expenditure (Opex) of the proposed system required to demonstrate it at a commercial level, including the cost of chemicals and electricity. The COD reduction cost evaluated were INR 140–230/kg COD depending on the effluent. The main highlight of the article is the practical demonstration at the manufacturing unit including the operating cost calculations.

Removal of BOD₅ and COD from Domestic Wastewater by Using a Multi-Media-Layering (MML) System

This study investigated the ability of the multi-media-layering (MML) to reduce Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) levels in domestic wastewater. MML used in this study is comprised of two MMLs (MML-1 and MML-2) with a total volume for each MML of 0.056 m³. Every MML was filled with gravel media, zeolite, activated carbon, and silica sand. The differences between MML-1 and MML-2 were only found at the height of the media, especially the height of gravel and zeolite media. This study showed that MML-1 had the highest efficiency in reducing BOD₅ (95.47%) and COD (93.10%) compared with MML-2 (BOD₅ of 85.39% and COD of 89.65%). Overall, MML showed promising results in removing pollutants from domestic wastewater. The study also suggested that the height of the gravel media and pH greatly influenced the removal of BOD₅ and COD levels in domestic wastewater.

Treatment of palm oil mill effluent using modified rotating biological contactor with organic loading rate variations

Indonesia is the world’s largest producer of palm oil or Crude Palm Oil (CPO). Palm oil production generates Palm Oil Mill Effluent (POME), which can harm the environment, if not properly treated. Untreated POME, with high Chemical Oxygen Demand (COD) levels, can lead to environmental degradations. Its high organic content and low acidity levels can also cause water pollution. This study modified the Rotating Biological Contactor (RBC) unit to treat POME, increasing the contact surface area between POME and microorganisms. It aimed to analyse the performance of the modified RBC unit, based on variations in organic loading rate (OLR). The study was conducted at a laboratory scale, with 2, 5, and 7 kgCOD/L/day organic loads. The results of this study revealed the highest percentage of removal obtained at an OLR variation of 7 kgCOD/L/day, with a removal rate of 70% for chemical oxygen demand (COD) concentration and 57% for ammonia concentration. Based on the research, the COD removal for organic loads of 7 kgCOD/L/day and 5 kgCOD/L/day decreased to 1900 mg/L and 2600 mg/L, respectively. Thus, the modified RBC unit would be more efficient with an organic load of 7 kgCOD/L/day. However, the COD concentration still did not comply with the water quality standards. Therefore, integrating the modified RBC unit with pre-treatment units, such as coagulation-flocculation, is necessary to achieve optimal effluent concentrations.

Efficient bioremediation of distillery and dairy wastewaters: A three-stage biorefinery for high-quality aquaculture feed and bioenergy generation

The present study is motivated by the need to address the environmental issues related to dairy and ethanol plant wastewaters and to generate valuable products, including mycoprotein and bioenergy, through a novel three-phase fungi-based biorefinery. In the initial phase of the biorefining process, the cultivation conditions of Aspergillus oryzae were optimized. The objective was to maximize mycoprotein production using wastewater as a resource. The effluent generated during the first phase of the biorefinery underwent the second phase, where it was subjected to cultivation with Neurospora intermedia. In the third phase, the effluent obtained from the fungal growth underwent anaerobic digestion as a final treatment step, producing 306 NmL methane/g VS. This three-phase biorefinery contributed to a remarkable reduction in the chemical oxygen demand level of the wastewater by 56.8%, 11.6%, and 28.1% in each respective phase. Overall, the three-phase biorefinery process yielded promising results, generating 17.8 kg of mycoprotein and 5.0 Nm3 of biomethane per cubic meter of wastewater. The mycoprotein obtained through this process contains noteworthy quantities of essential amino acids, fatty acids, and minerals. These characteristics open up opportunities for substituting conventional feed in aquaculture with the produced mycoprotein.

Coupling Iron Sludge Addition and Intermittent Aeration for Achieving Simultaneous Methanogenesis, Feammox, and Denitrification in a Single Reactor Treating Fish Sludge.

An integrated anaerobic digestion system for the simultaneous removal of carbon and nitrogen from fish sludge was developed by coupling iron sludge supplementation with intermittent aeration. In terms of nitrogen removal, Fe(III) in iron sludge could trigger Feammox reactions and intermittent aeration could drive the Fe(II)/Fe(III) cycle to sustain continuous ammonia removal. Mass balance analysis suggested that nitrate was the main product of Feammox, which was subsequently removed through heterotrophic denitrification. In terms of carbon removal, the Fe(III)-induced dissimilatory iron reduction (DIR) process significantly promoted fish sludge hydrolysis and provided more simple organics for methanogens and denitrifiers, but aeration showed a negative impact on methanogenesis. To promote nitrogen removal and avoid serious methanogenesis inhibition, different aeration intensities were studied. Results showed that compared with the control without aeration or iron sludge addition, aeration for 5 min every 3 days (150 mL/min) contributed to a 29.0% lower NH4+-N concentration and a 12.1% lower total chemical oxygen demand level on day 28, and the decline in methane yield was acceptable (only 13.5% lower). Simultaneous methanogenesis, Feammox, and denitrification in a single reactor treating fish sludge were achieved, which provides a simple and low-cost strategy for the treatment of organic wastewater.

Natural sunlight-driven enhanced abatement of real resin industry wastewater using sludge-derived photocatalyst: Potential to generate carbon credits

The resin manufacturing industry is one of the industrial sectors that consumes huge quantities of water and generates enormous quantities of toxic wastewater with a high level of chemical oxygen demand (COD). In the present study, the performance of an optimized copped-doped raw galvanic waste-derived (CRGW) photocatalyst was evaluated in a novel stirred tank photoreactor in batch and continuous configurations as a possible solution for the treatment of real resin industry wastewater (RIW) under natural sunlight. Under optimal operating conditions, a COD removal rate of 70.3% and 43.5% was observed in batch and continuous configurations within 4 h, respectively. The photoreactor in continuous mode was aided by a magnetic bed that anchored the photocatalyst to the reaction segment without subsequent retrieval from the treated effluent. The mixture of pollutants in the RIW underwent photodegradation due to a pronounced bathochromic shift in UV absorption. Moreover, the XRD and XPS results confirmed the crystallinity and successful charge migration in the synthesized CRGW. The applicability of the photocatalyst for degradation of RIW was demonstrated through an economic analysis, and its specific cost was determined to be 9.5 USD/m3 of treated wastewater. Furthermore, this study aims to be a step toward generating carbon credits by avoiding the release of 18 tons of CO2/yr into the atmosphere by utilizing natural sunlight for photodegradation. The reduction, avoidance, or removal of greenhouse gases is pivotal in today’s world, and carbon credits can accelerate this transformational journey towards a sustainable future.

Comparison of COD Determination Methods FAS Titrimetric with UV-Vis Spectrophotometry

Liquid waste is one of the factors causing contamination of the aquatic environment. One of the chemical parameters of water quality namely Chemical Oxygen Demand (COD). This research was conducted at three different concentration levels, namely low, medium, and high, with samples of river water, domestic wastewater, and sago liquid waste. The method used is UV-Vis spectrophotometry (SNI 6989.2: 2019) and FAS titrimetry (APHA, 2017 methods 5220 D); for the UV-Vis spectrophotometry method in the range 90 mg/L, the wavelength was measured at 420 nm, while for high levels in the range 100 mg/L x 900 mg/L, it was measured at 600 nm. The quality control parameters used are accuracy and precision parameters. The purpose of this study was to compare the COD determination between UV-vis spectrophotometry and FAS titrimetry and to determine the validity and correlation of the two methods—a comparison of the results of the two methods used in the F test. The results showed that the COD values from UV visible spectrophotometry and FAS titrimetry yielded good precision and accuracy values and met the acceptable limits, namely %RSD 10% and 90% accuracy %R 110%. However, the results of the COD analysis using the UV-Vis spectrophotometry method were lower by 0.8556 than the results of the COD analysis using the FAS titration method, with a correlation coefficient r2 = 0.982. The average concentration of UV-Vis spectrophotometry in samples of sago wastewater was 572.141 mg/L, domestic wastewater was 113.525 mg/L, and river water was 42.98 mg/L. The average COD level of the titrimetric method in sago wastewater was 641.888 mg/L, domestic wastewater was 219.251 mg/L, and river water was 58.016 mg/L. The results of the F test for these two methods produce an Fcount Ftable. The null hypothesis (Ho) is rejected, meaning there is a significant difference between the two methods.

Assessment of the Environmental Impact of Discharges from Fishmeal Factories Located in Levrier Bay, Nouadhibou-Mauritania

Levrier Bay, located in the western part of Mauritanian Cost, has a strategic position in Mauritania’s fish economy and reproduction environment. Recently, fishmeal factories have multiplied in the bay. This study was carried out in Levrier Bay. It is the first one in this area which is interested in assessing the environmental impact of fishmeal factory discharges by measuring several parameters such as suspended matter, chemical oxygen demand (COD), biological oxygen demand (BOD), conductivity, turbidity, and salinity. A total of 27 samples were collected at 9 sites distributed on the link between effluents from factories and the Atlantic Ocean (discharge site). Results show that some parameters are over permissible values, like suspended matter content (SS), which reached 2020 mg. L.-1 level. The turbidity measure shows excessively high values (50 to 961 mg.L.-1); impacted by effluents at the reject point, the seawater conductivity and salinity are particularly low (4.53 to 188.2 and 13 to 56.4, respectively). The total organic carbon (TOC) values ranged from 200 to 780 mg/L, whereas the highest measured level of chemical oxygen demand was 4010 mg.L.-1 Biochemical oxygen demand content ranged from 685 to 961 mg/L. The biodegradability index (COD/BOD) shows that these effluents are not easily biodegradable because the index > 3.

Reducing Chemical Oxygen Demand and Turbidity Levels in Laundry Waste Using Activated Carbon from Water Hyacinth Leaves

Lignocellulose compounds contained in water hyacinth leaves (WHL) (Eichhornia crassipes) can be used as raw material for the manufacture of activated carbon at a low and renewable rate. The ACWHL can be used as adsorbent for reducing a COD value and turbidity levels on laundry waste. The purpose of this study is to determine the best adsorption modelling of ACWHL on COD values and turbidity levels in laundry waste in kinetics and isotherm studies and determine the effectiveness of reducing a COD value and turbidity levels. The process of making ACWHL is carried out by carbonization at 400 °C for 1 hour, then activated using 30% H3PO4 at an impregnation ratio of 1:4 (w/w) for 24 hours and physical activation at 600 °C for 1 hour. The results showed that the adsorption of ACWHL on COD value and turbidity levels of laundry waste followed Freundlich isotherm and Elovich isotherm modelling with R2 values of 0.9535 and 0.9905, respectively. The modelling for adsorption kinetics of COD values and turbidity levels in laundry waste follows the Pseudo Second Order kinetics modelling. The effectiveness of ACWHL reduction in adsorption of COD value and turbidity levels of laundry waste was 80.76% and 64.71%.

Comparative evaluation of low-cost ceramic membrane and polymeric micro membrane in algal membrane photobioreactor for wastewater treatment

Algal-bacterial membrane photobioreactor (AMPBR) is proven as a highly energy-efficient process for treating domestic wastewater. This study compared the application of polymeric micro-membrane (PMM) and a low-cost ceramic membrane (LCM) to the AMPBR process for treating domestic wastewater with low and high organic pollution levels. Experiments were conducted over 57 days using two PMM-AMPBRs and two LCM-AMPBRs, operating on a 12-h dark/light cycle in a continuous mode. Simulated wastewater containing varying levels of chemical oxygen demand (COD) was fed to reactors for a consistent hydraulic residence time (HRT) of 7 d and a flux rate of 100 L/m2/d. PMM and LCM-AMPBRs demonstrated efficient wastewater treatment capabilities, achieving COD removal rates exceeding 94% and 95% for high and low COD loadings, respectively. PMM-AMPBR achieved 54.1% TN removal at low COD loading, while LCM-AMPBR achieved 57.2%. These removal efficiencies decreased to 45.6% and 47.0% under high COD loading. Total Phosphorus (TP) removal reached 29–33% for PMM-AMPBRs and 21–24% for LCM-AMPBRs, irrespective of COD loading. LCM-AMPBRs showed significantly lower fouling frequency than PMM-AMPBRs. The biomass production rate decreased with increasing COD loading and achieved 40 mg/L/d at low COD loading for both AMPBRs. Net energy return (NER) values for both AMPBRs were close to 0.87, indicating them as energy-efficient processes. Considering the cost-effectiveness and comparable performance, LCM-AMPBR could be a viable alternative to PMM-AMPBR for wastewater treatment, particularly under low COD loading conditions.

Efficacy of Biogenic Zinc Oxide Nanoparticles in Treating Wastewater for Sustainable Wheat Cultivation.

Water scarcity due to overuse and growing water pollution has led to the need for upgrading of conventional methods of wastewater treatment. The biological synthesis of zinc oxide nanoparticles (ZnO-NPs) and their photocatalytic capacity to degrade contaminants offer a promising and environment-friendly approach to municipal wastewater treatment. This technique is advantageous due to its cost-effectiveness, sustainability, and reduction in toxic residual substances. In this study, microbial-synthesized ZnO-NPs were used for the treatment of municipal wastewater. The objective of this study was to evaluate the potential of treated wastewater for wheat crop cultivation. Zinc oxide nanoparticles were synthesized from a pre-isolated bacterial strain, namely Shewanela sp., and characterized using UV-VIS, X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) analyses. The results showed that after the treatment of wastewater, the concentration of total dissolve solids (TDS), the chemical oxygen demand (COD), and sulfate and phosphate levels decreased by 76.5%, 57.1%, 81.1%, and 67.4%, respectively. However, the application of treated wastewater increased chlorophyll, carotenoids, and antioxidants by 45%, 40.8%, and 10.5 to 30.6%, respectively. Further, the application of treated wastewater also significantly decreased oxidative stress induced by hydrogen peroxide (H2O2) and malondialdehyde (MDA) by 8.1% and 30.1%, respectively. In conclusion, biosynthesized ZnO-NPs could be an important choice to treat municipal wastewater and to improve wheat productivity.

Moringa oleifera organic coagulant to eliminate pollution in olive oil mill wastewater

Wastewater from the olive oil mill (OMW) is an environmental hazard as it contains toxic and persistent compounds with significant organic load and high turbidity. The purpose of the present investigation is to assess the effectiveness of OMW treatment by flotation and coagulation procedure using Moringa oleifera. Physicochemical analysis of OMW showed high levels of the original chemical oxygen demand (COD) with a concentration of about 230.4 g/L, turbidity, and polyphenols with an initial concentration of around 5.4 g/L. After natural flotation, polyphenols, turbidity, and COD were reduced by 16.6%, 50%, and 31.2%, respectively. Turbidity, suspended solids, COD, polyphenols, and nitrates were all removed by natural flotation and coagulation by Moringa oleifera with percentages of about 83%, 74.5%, 57.6%, 65.6%, and 73.3%, respectively. Principal component correlation analysis between pollution removal parameters indicates that all variances are in the first component, with pH, nitrate, polyphenol, COD, and turbidity concentrations positively correlated. The proposed treatment process, which uses Moringa oleifera as a coagulant, can be applied in many industries due to its unique characteristics, including cheap cost and environmentally friendly approach.

Performance of tubular microbial fuel cells using different industrial wastewater

Microbial fuel cells (MFCs) can potentially ameliorate the extensive use of energy in the biological treatment step of wastewater treatment, among other benefits. This paper investigated the use of MFCs for different types of industrial wastewater using carbon fuel cell electrodes. The MFCs were inoculated with activated sludge and operated with industrial wastewater collected from Kuwait's most common industries (dairy, detergents, petrochemicals, and soft drinks). The results showed that MFCs have successively generated electricity from all industrial wastewater, except for that from the petrochemical industry. The MFCs achieved a maximum power density of 86 mW/m3 (dairy wastewater), 41 mW/m3 (detergents wastewater), 20 mW/m3 (soft drink wastewater), and 1 mW/m3 (petrochemical wastewater). Furthermore, the MFCs achieved an average Chemical Oxygen Demand (COD) removal efficiency of 75 % (dairy wastewater), 44 % (detergent wastewater), 7 % (petrochemical wastewater), and 79 % (soft drink wastewater). Conceivably, these removal rates correspond to bioelectrochemical utilization of the organic matter present in the different types of industrial wastewater to produce energy. Increasing batch duration from 7 to 14 days did not influence nutrients and heavy metals removal. In addition, it was found that the application of MFCs for petrochemical wastewater treatment was influenced by (high COD level = 15,114 mg/L), the content of inhibitive chemicals (such as surfactant, dimethylpolysiloxane, ferric sulfate, and benzalkonium chloride), and the hydrophobicity of the organics leading to deterioration in fuel cell electrode performance, catalyst deactivation, and generally unfavourable microbial growth conditions.

A Hybrid Ultrasonic Membrane Anaerobic System (UMAS) Development for Palm Oil Mill Effluent (POME) Treatment

The high chemical oxygen demand (COD) and biochemical oxygen demand (BOD) levels in palm oil mill effluent (POME) wastewater make it an environmental contaminant. Moreover, conventional POME wastewater treatment approaches pose economic and environmental risks. The present study employed an ultrasonic membrane anaerobic system (UMAS) to treat POME. Resultantly, six steady states were procured when a kinetic assessment involving 11,800–21,700 mg·L−1 of mixed liquor suspended solids (MLSS) and 9800–16,800 mg·L−1 of mixed liquor volatile suspended solids (MLVSS) was conducted. The POME treatment kinetics were explained with kinetic equations derived by Monod, Contois and Chen and Hashimoto for organic at loading rates within the 1–11 kg·COD·m−3·d−1 range. The UMAS proposed successfully removed 96.6–98.4% COD with a 7.5 day hydraulic retention time. The Y value was 0.67 g·VSS/g·COD, while the specific micro-organism decay rate, b was 0.24 day−1. Methane (CH4) gas production ranged from 0.24 to 0.59 litres per gram of COD daily. Once the initial steady state was achieved, the incoming COD concentrations increased to 88,100 mg·L−1. The three kinetic models recorded a minimum calculated solids retention time of 12.1 days with maximum substrate utilization rate, K values ranging from 0.340 to 0.527 COD·g−1·VSS·d−1 and maximum specific growth rate, µmax from 0.248 to 0.474 d−1. Furthermore, the solids retention time (SRT) was reduced from 500 to 12.1 days, resulting in a 98.4% COD level reduction to 1400 mg·L−1.