Effluent Concentrations Research Articles

SOIL POLLUTION AND HEAVY METAL CONTAMINATION: INSIGHT FROM EFFLUENT DISCHARGED FROM CHALLAWA INDUSTRIAL AREA, NIGERIA

The discharge of industrial wastewater represents a significant source of environmental pollution, particularly in developing regions where regulatory enforcement is often insufficient. This study examined the chemical characteristics of effluent discharged from three locations (LA, LB, and LC) close to the Challawa Industrial Area in Kano, Nigeria, and determined their effects on nearby soil. Effluent samples were analysed for pH, biochemical oxygen demand (BOD), phosphates (PO), nitrates (NO-N) and critical toxic heavy metals (HMs) such as lead (Pb), chromium (Cr), copper (Cu), Zinc (Zn) and cadmium (Cd). Simultaneously, soil samples from three locations near the discharge point were evaluated for pH, total nitrogen (TN), and total phosphorus (TP). The results revealed that effluent concentrations of HMs and nutrients far exceeded the permissible limits of the National Environmental Standards and Regulations Enforcement Agency. The Pb (90.79 mg/L), Cd (10.06 g/L), Zn (33.43 mg/L), Cr (4.49 mg/L), and Cu (12.76 mg/L) concentrations were well above the regulatory limits of 0.05 mg/L, 0.01 mg/L, 0.05 mg/L, 0.01 mg/L, and 0.02 mg/L, respectively. The Phosphate (299.74 mg/L) and nitrate (381.97 mg/L) levels also exceeded NESREA standards, indicating a significant risk of eutrophication in nearby water bodies. Regression analysis revealed that higher pH tended to increase the concentration of both nutrients, with P showing a more consistent and stronger association (p<0.05) than nitrogen. This study, therefore, highlight that HMs contamination is evident in the soils around the study area, posing risks to soil fertility and agricultural productivity.

Removal of organic pollutants from paper mill effluent using Taro (Colocasia esculenta L. Schott) in an electro-assisted horizontal subsurface flow constructed wetland: Experimental and kinetic studies.

In this study, the phytoremediation potential of Taro (Colocasia esculenta L. Schott) plant was examined, utilizing horizontal subsurface flow constructed wetlands with and without an electric current supply for the purpose of removing pollutants from paper mill effluent. For this, different wetlands were set up with varying concentrations of effluent: CW (Control), CW1 (25%), CW2 (50%), CW3 (75%), CW4 (100%). After 45days, the highest plant height (85.13 ± 4.24cm), leaf area index( 250.83 ± 10.14), fresh biomass (565.30 ± 6 .10g), root biomass (392.85 ± 4.34g), root-to-shoot ratio (2.41 ± 2.10), relative growth rate (0.044 ± 0.002 gg-1d-1), and chlorophyll content (3.29 ± 0.07mg/g fwt) was observed in CW2 with current supply, along with significant removal of pollutants (pH: 7.13 ± 0.15, EC: 2.33 ± 0.07 dS/m, TDS: 192.52 ± 6.12mg/L, COD: 490.17 ± 5.01mg/L, BOD: 206.74 ± 5.92mg/L, potassium: 73.27 ± 4.11mg/L, sodium: 46.62 ± 2.27mg/L, phosphate phosphorus: 34.08 ± 1.43mg/L, and nitrate nitrogen: 104.85 ± 5.94mg/L) and highest first-order rate constant (k) values. Furthermore, the microbial community assessment of constructed wetlands using V3-V4 16S rRNA sequence data was prepared on the Illumina MiSeq framework. The major phyla identified were Proteobacteria, Firmicutes, Bacteroidetes, Actinobacteria, Chloroflexi, Acidobacteria, Nitrospirae, Planctomycetes, and others. The findings offer innovative insights for sustainable wastewater treatment strategies through phytoremediation of paper mill effluent using Taro plants in modified constructed wetlands and highlight the role of diverse microbial communities capable of degrading various pollutants in wastewater.

Development of a fully integrated hydrological fate and transport model for plant protection products: incorporating groundwater, tile drainage, and runoff

IntroductionPlant protection products (PPPs) such as pesticides and herbicides are experiencing increased use worldwide. In the context of PPP authorization and registration, water exposure assessments (drinking water and aquatic exposure) use numerical modeling to simulate relevant hydrological processes and exposure pathways. A common practice for estimating PPP leaching to groundwater, PPP loading onto surface water via tile drainage, or PPP transport via runoff utilizes multiple one-dimensional models, each representing a separate exposure pathway. Separate analysis of individual exposure pathways can result in disparate assumptions being made that represent relative worst-case scenarios for each pathway, rather than an integrated reasonable worst-case scenario for all pathways.MethodsThe interplay between PPP degradation, leaching to groundwater, transport in tile drainage, and runoff is well-suited for simulation using an integrated surface–subsurface hydrologic and chemical fate and transport model. This study presents functionality added to HydroGeoSphere (HGS), a three-dimensional, fully integrated, surface–subsurface hydrologic model. HGS was verified against other recognized models: PRZM, HYDRUS, PEARL, PELMO, and MACRO. Added features include automatic irrigation, non-linear adsorption, temperature and soil water content-dependent degradation, and solute uptake by plant roots.Results and DiscussionHGS results for leaching of PPP mass to groundwater showed the highest correlation, lowest error, and lowest bias relative to PEARL model results. Simulation of macropore flow to tile drains in HGS produced an intermittent tile drain flow in summer that resulted in generally lower peak effluent concentrations compared to the MACRO model. Simulation of runoff in HGS produced a higher total runoff compared to the PRZM model, attributed to lower evapotranspiration in HGS. Use of the integrated HGS model resulted in a greater agreement in water balance components relative to using multiple models to simulate individual hydrologic pathways.

Analysis on pollutants removal and sludge characteristics of a novel two-phase anaerobic/aerobic/integrated deoxygenated and anoxic reactor associated with membrane process for treating pesticide wastewater

Most frequently used biological method was improved anaerobic/anoxic/aerobic (A/A/O) process for treating actual pesticide wastewater presently. However, the effluent results were far away from what the national standard expects due to pesticide wastewater characteristics of high COD concentration, high total nitrogen (TN) concentration and high toxicity. In this study, a novel two-phase anaerobic/aerobic/integrated deoxygenated and anoxic reactor associated with membrane process (P1) were regarded as excellent candidates for the treatment of pesticide wastewater, compared the removal efficiency of pollutants with improved A/A/O process (P2) under different hydraulic retention times (HRTs). Effluent ethylene thiourea (ETU) concentration was reduced effectively by 67.1 % in P1. The average cyanide (CN−) effluent concentration in P1 and P2 was 0.40 mg/L and 6.67 mg/L, respectively. During the entire HRT change period, P1 significantly increased the biological oxygen demand (BOD5) removal efficiency by 12.98 %. The average effluent COD concentration of P1 was 36.41 mg/L, while that of P2 was 984.42 mg/L. In addition, TN removal efficiency of P1 exhibited distinct superiority. When HRT was 72 h, the average TN effluent concentration of P1 and P2 was 12.67 mg/L and 67.66 mg/L. The sludge performance indicators have been determined and results showed that the sludge viscosity of the membrane reactor in P1 had merely 32.6 % higher than that of the secondary sedimentation tank in P2, and the average vertical displacement of sludge settleability in P1 was 23.0 % slight lower than that of P2. The overall sludge performance proved that higher sludge concentration was allowed in P1. Moreover, experiment improved nitrite reductase (NIR) and nitrate reductase (NAR) in P1 were less susceptible to be suppressed by ETU and CN− increase compared with P2. Finally, the positive correlation relationship of sludge settleability with ETU and CN− has been identified successfully in P1.

Preparation and optimization of sulfur ferrous inorganic carbon composite filler for autotrophic denitrification nitrogen and phosphorus removal

Sulfur autotrophic denitrification (SAD) occurs without organic carbon sources, offering advantages in removing nitrogen pollutants from water with low carbon to nitrogen ratio. However, ensuring nitrate–reducing sulfide–oxidizing bacteria ability to access the necessary sulfur and inorganic carbon sources is a challenge. Therefore, this study investigated the feasibility of utilizing a SAD composite filler to mitigate nitrogen and phosphorus pollutants concentrations in secondary effluent of wastewater treatment plants (WWTPs) and reduce eutrophication risk in the receiving water. The use of paraffin optimized composite filler with a satisfying 3.70 % break rate and wear rate without dramatically deteriorating contaminant removal performance. The process achieved 94.26 % total nitrogen (TN) and 90.91 % PO43--P removal rates in treating synthetic wastewater; and 2.72±1.92 and 0.29±0.06 mg/L of TN and PO43--P discharge in treating WWTPs secondary effluent, respectively. The results indicated that denitrification performance of the filler was primarily influenced by variations in NH4+-N resulting from SAD and dissimilatory nitrate reduction to ammonia caused by differences in filler composition and preparation factors. Based on the performance difference in SAD, Fex+ leached by H+ in the filler changed, affecting phosphorus removal performance. The change in mechanical properties of the filler was primarily dependent on the surface characteristics of the filler and the content/type of the binder. This study demonstrates the feasibility of using SAD for advanced nitrogen and phosphorus removal from wastewater and applying sulfur/siderite integrated composite filler as a pilot, thereby offering insights for the preparation of SAD fillers.

Enhanced nitrogen removal for low C/N wastewater via preventing futile carbon oxidation and augmenting anammox

Efficient carbon use is crucial for biological nitrogen removal. Traditional aerobic processes can waste carbon sources, exacerbating carbon deficiency. This study explores an anaerobic/oxic/anoxic system with sludge double recirculation to improve nitrogen removal in low C/N wastewater. This system integrated aerobic nitrification after the carbon intracellular storage, separating carbon and nitrogen by denitrifying glycogen-accumulating organisms (DGAOs) with endogenous partial denitrification and Anammox within the anoxic units. A significant efficiency of 91.02±7.01% chemical oxygen demand (COD) was converted into intracellular carbon in anaerobic units, significantly reducing carbon futile oxidation in the aerobic units by effectively separating COD from ammonia. Intracellular storage of carbon sources and microbial adaptation to carbon scarcity prevent futile oxidation of COD in the aerobic units even with short-term high dissolved oxygen (DO), thereby enhancing nitrogen removal under anoxic conditions with sufficient intracellular carbon source. The microbial analysis identified Candidatus Brocadia as the dominant anammox bacteria, in combination with the activity of DGAOs and other related microbial communities, accounting for 37.0% of the TN removal. Consequently, the system demonstrated remarkable nitrogen removal efficiencies, achieving 81.3±3.3% for total nitrogen (TN) and 98.5±0.9% for ammonia nitrogen while maintaining an effluent COD concentration of 17.2±9.1 mg/L, treating the low C/N of 4.18 in the influent wastewater. The findings in this study provide a sustainable and energy-saving technique for conventional WWTPs to meet strict discharge standards by avoiding futile oxidation of COD and encouraging anammox contributions.

Optimized Irrigation Strategies for Saline Soil Remediation in Agricultural Lands Under Water-Limited Conditions

Soil salinization is a prevalent global issue, significantly impacting crop cultivation and food production. This study investigates the potential of sustainably harnessing rainwater for the remediation of saline soils in water-scarce regions. Soil column leaching experiments were performed to evaluate the effectiveness of different methods for salt removal from the tillage layer. The findings demonstrated that intermittent leaching was more effective than continuous leaching in remediating NaCl-type saline soils. When continuous leaching with 27 cm of rainwater was applied, the salt removal in soil layers below 5 cm ranged from 12.28% to 26.86%. Intermittent leaching increased the salt removal rate to between 44.49% and 54.18%. This higher desalination efficiency of intermittent leaching is attributable to the extended soil–water contact time. When the leaching time in continuous leaching was increased from 1.5 h to over 4.5 h, comparable desalination effects were produced. The rainwater leaching demonstrated similar salt removal patterns in Na2SO4-type saline soils. However, due to the stronger affinity of SO42− for clay particles, their effluent concentration and removal were lower than Cl− under the same conditions. To optimize desalination efficiency, operational parameters can be adjusted to reduce the leaching depth of rainwater from 27 cm to 15 cm, and the interval between leaching events from 24 h to 4.5 h. The findings of this study may serve as a valuable reference for saline soil restoration and improvement efforts in water-scarce regions.

Utilizing Tetradesmus obliquus for Phycoremediation Enhanced Nitrogen and Phosphorus Removal in Urban Wastewater Treatment

Microalgae can scavenge pollutants through a process called phycoremediation, which involves the removal or biotransformation of pollutants in wastewater and gaseous media. Algae must grow rapidly, tolerate seasonal and diurnal variations, and form aggregates easily. In this study, the phosphorus and nitrogen removal capacity of the microalga Tetradesmus obliquus, isolated from urban water bodies, was evaluated and its cultivation was proposed as an alternative for tertiary treatment of urban effluents. The inoculum was placed in a bioreactor at 25 ºC with natural lighting for 21 days in modified Bold Basal Medium (BBM). The experiment included a control group (BBM) and a treatment with distilled water (AD) and increasing concentrations of urban effluent (12.5%, 25%, 50%, and 100%), inoculated with 8.8x105 cells/ml of biomass. The treatments were carried out in triplicate for 15 days. pH, dissolved oxygen (DO), conductivity, NO3- and PO4-3 concentrations, and biological variables such as cell count and optical density were determined. Tetradesmus obliquus showed efficiency in removing phosphates and nitrates. Maximum efficiency was shown after 15 days of treatment with 100% effluent, removing 22.92% of phosphates and 65.66% of nitrates.

Insight into heterovalent metal modification for lanthanum carbonate to enhance phosphate removal at trace levels

Reducing phosphate concentrations from low levels to ultra-low levels (e.g., below 0.01 mg P/L) is crucial for preventing and treating eutrophication. Adsorption is promising but still challenged by the limited adsorption capacity at low phosphate concentrations, which leads to high costs. Herein, we propose a heterovalent metal modification strategy using Fe(II) to improve the adsorption capacity of lanthanum (La) carbonate for low-level phosphate removal. A La:Fe(II) molar ratio of 7:1 enabled the partial substitution of Fe(II) for La, resulting in a La/Fe carbonate with a high adsorption capacity. La/Fe carbonate exhibited fast adsorption kinetics, excellent applicability in a pH range of 5–7, and good reusability at low phosphate concentrations. Its adsorption capacity at low phosphate levels surpassed previously reported adsorbents. La/Fe carbonate demonstrated high resistance to complex water matrices and cost-effectiveness, achieving an effluent concentration below 0.01 mg P/L in real wastewater treatment. Mechanism analysis revealed that Fe(II) substitution led to super-saturated coordination and Fe(II) → Fe(III) conversion for charge compensation. The self-conversion of Fe(II) → Fe(III) donated electrons to neighboring La active sites, activating these active centers, which caused a positive shift in the d-band center of La active sites and enhanced interfacial electron transport between La/Fe carbonate and phosphate. This work offers an efficient, easy-to-operate, and low-cost approach to achieve ultra-low phosphate concentrations through adsorption, and fills the research gap on the mechanism of heterovalent metal modulation to enhance the phosphate adsorption capacity.

Molecular insights: zebrafish embryo damage linked to hospital effluent.

This study addresses the pressing issue of pollutants, particularly heavy metals and pharmaceuticals, infiltrating aquatic ecosystems due to untreated hospital effluents. These contaminants, known for their toxicity and bioaccumulative potential, adversely affect water quality and ecosystem health. The research focuses on the intricate relationship between oxidative stress and embryonic damage in Danio rerio exposed to hospital effluent, offering a detailed understanding of the underlying mechanisms. Concentrations of pharmaceutical residues (ng L-1) such as NSAIDs, corticosteroids, proton pump inhibitors, H2-receptor antagonists, and heavy metals (mg L-1) like Cd, As, Cu, Cr, Hg, Ni, Pb, and Zn were meticulously quantified. The effluent exhibited a significant embryolethal potential with an LC50 of 2.328% and an EC50 for malformation at 2.607%. Notable embryonic malformations included yolk sac edema, tail abnormalities, pericardial edema, scoliosis, craniofacial deformities, eye hypopigmentation, developmental delays, and body malformations. Zebrafish embryos were exposed to varying concentrations of the effluent (0.5% to 4.0%) and assessed for lethality and malformations at specific intervals (12, 24, 48, 72, and 96h post-fertilization). The study also scrutinized oxidative damage and monitored the expression of genes central to antioxidant processes, detoxification, and apoptosis (sod, cat, nrf2, cyp1a1, bax, casp3, casp6, casp7, and casp9) at 48-, 72-, and 96-h post-fertilization across all concentrations. Findings consistently revealed lipid and protein damage, heightened antioxidant activity, and altered gene expression at all time points and effluent concentrations. These results highlight the environmental threat posed by untreated hospital effluent, emphasizing the need for comprehensive effluent treatment measures to protect aquatic ecosystems from the detrimental impacts of pharmaceuticals and heavy metals. The study underscores the critical role of oxidative stress in embryonic damage and advocates for improved environmental stewardship and regulatory measures.

Total ammonia removal from anaerobic digestion effluents of municipal sewage sludge using Nordic microalgae

The treatment of organic waste using anaerobic digestion is a promising and well-matured organic waste management method. However, the effluent from anaerobic digestion has a significant discharge risk due to its high ammonium content. Microalgae could be a valuable solution to remove this nitrogen. This work aimed at evaluating the growth of three Nordic microalgae strains (Chlorella vulgaris, Chlorococcum sp. and Coelastrella sp.) in different concentrations of effluent from anaerobic digestion of municipal sewage sludge. None of the strains was able to grow in effluent diluted two times (X2) or three times (X3) due to the high ammonium content (600 and 400 mg L−1, respectively). While Chlorococcum sp. showed a lag phase of 7 and 11-days in 5 times (X5) and 7 times (X7) diluted effluent, respectively, this strain demonstrated 53 % and 86 % total ammonia nitrogen (TAN) removal efficiency after 15 days; in X10 its TAN removal was 100 %. Without any lag phase Coelastrella sp. showed the same TAN removal efficiencies in X5 and X7 as Chlorococcum sp. However, C. vulgaris had the highest TAN removal in X5 (90%) and X7 (90%). Furthermore, this strain showed the highest amount of biomass dry weight production in all media (1.1 g L−1 in X5). Therefore, C. vulgaris and Chlorococcum sp. are promising candidates for nitrogen removal and sustainable algae biomass production, resulting in mitigating the environmental issues of anaerobic digestion effluents in Nordic countries through the conversion of waste streams into resources.

Microplastic Contamination in Landfill Leachate and Surface Water: Assessment of Wastewater Treatment Efficiency at the Nonthaburi Waste Management Center, Thailand

Microplastics (MPs), plastic particles smaller than 5 mm, have emerged as a significant environmental concern, particularly as contaminants originating from landfills. Landfills can serve as a major source of MPs, potentially releasing them into surface water through leachate. This study aims to investigate the contamination of MPs in leachate and surface water, as well as to evaluate the efficiency of landfill wastewater treatment in removing these particles. The research was conducted at the Waste Management Center of the Nonthaburi Provincial Administrative Organization, Thailand, with samples collected in June 2023. Sampling included two leachate sources, influent and effluent from the treatment system and surface water. The abundance and characteristics of MPs in each sample were analyzed. Results indicated a significant presence of MPs in leachate, with an average concentration of 173.98 pieces/L, while concentrations in influent, effluent and surface water were 38.40 pieces/L, 10.80 pieces/L and 11.33 pieces/L, respectively. MPs in all samples were predominantly in the size range of 16-100 µm, corresponding to 71.28-93.75% of the total particles. Polypropylene was the dominant polymer in leachate (69.66%) and effluent (48.94%), whereas acrylate copolymer (96.53%) and polytetrafluoroethylene (44.12%) were the major types found in influent and surface water, respectively. The wastewater treatment system of the landfill demonstrated an overall removal efficiency of 71.88% for MPs in leachate. These findings highlight the extent of MP contamination in landfill environments and the importance of improving treatment processes to mitigate their release into surrounding ecosystems.

Measuring Microplastic Concentrations in Water by Electrical Impedance Spectroscopy

Plastics are vital for society, but their usage has grown exponentially and contributes to the growth of pollution worldwide. The World Health Organization, WHO, already reported that microplastics (MPs) are found everywhere, in waste and fresh water, and in the air and soil. Regarding water effluents, waste-water treatment plants only minimize the problem, trapping only larger size particles. In contrast, smaller ones remain in oxidation ponds or sewage sludges, or are even released to aquifers environment. Classic procedures for MPs detection are still quite laborious, and are usually conducted off-line, involving several steps and expensive equipment. Electrical Impedance Spectroscopy, EIS, is a technique that allows the analysis of a system’s electrical response, yielding helpful information about its domain-dependent on physical-chemical properties. Due to the superficial electronegativity of MPs’ particles, EIS may allow to attain the purpose of the present work: to provide a fast and reliable method to detect/estimate MPs’ concentration in water effluents. Among the most common microplastics are Polyethylene, PE, and Polyvinyl Chloride, PVC. Using the developed setup and experimental data collection methodology, the authors could differentiate between MPs’ suspensions containing the same concentration of the different evaluated MPs, PVC and PE, and assess PVC concentration variation, in the interval between 0.03 to 0.5 g (w/w), with an error, estimated based on the obtained impedance modulus, around or below 3% for the entire stimulus signal frequency range (from 100 Hz to 40 MHz) for the PVC particles.

Study on Operation Effect of Two-Stage MSL System for Rural Decentralized Sewage Treatment

To improve the removal efficiency of rural domestic sewage, a two-stage multi-soil-layer sewage treatment system with an “aeration section + non-aeration section” was designed, and its treatment performance was observed under different influent loads and aeration intensities. The experiment ran for a total of 150 days, and the results showed that the two-stage multi-soil-layer (MSL) system could effectively reduce the effluent concentration of sewage to meet discharge standards. Under the operating conditions of an influent hydraulic load of 1000 L·m−2·d−1 and an air–water ratio of 4:1, the final effluent average concentrations of COD, NH3-N, TN, and TP were 106.5 mg·L−1, 7.4 mg·L−1, 13.9 mg·L−1, 0.12 mg·L−1, and 18.6 mg·L−1, respectively, with average removal rates of 85.3%, 82%, 72.5%, 96%, and 85%. A longer hydraulic retention time and ideal anoxic conditions were ensured by designing a certain effluent height in the system. Adding aeration to the system allowed for a synchronous nitrification–denitrification reaction under reasonable influent loads, ultimately enabling the effluent to meet discharge standards.

Systematic evaluation of swale length, shape, and longitudinal slope with simulated highway runoff for better swale design.

Swales are a low-cost, conveyance and treatment system to manage roadway runoff, but available design guidance is limited. Eight grass swales were constructed in Raleigh, North Carolina, USA, to systematically evaluate the effects of design factors: length, shape, and longitudinal slope under two different storm sizes. Water from an onsite reservoir was used to generate synthetic runoff and simulate flow through the swales. Inflow volume, total suspended sediment (TSS), nitrogen, phosphorus, and four total metals (copper, lead, zinc, and cadmium) were tested with simulated levels representing highway runoff. Efficiency ratios were used to estimate the reductions in inflow volume, pollutant concentrations, and mass loads. Swale length, shape, longitudinal slope, and storm size significantly influenced runoff volume reduction. The longer (30m) trapezoidal swale constructed on the flatter (1%) longitudinal slope provided maximum reductions in sediment and heavy metal concentrations during small-medium storms. Larger storms had modestly reduced pollutant and volume mitigation. Effluent nutrient concentrations generally exceeded the influent exporting nitrogen and phosphorus from all swale configurations. Significantly better pollutant load reductions were provided by the longer swales for all pollutants, except dissolved phosphorus. Therefore, to optimize swale function, designers could maximize the swale length to the greatest extent practicable, particularly when swales receive inflow from end-of-pipe systems draining roadway surfaces. The trapezoidal cross-section was superior to the triangular cross-section for stormwater treatment. Proper vegetation establishment and maintaining optimal grass height are key to proper swale functioning.

Influence of rubber particle inputs on nitrogen removal efficiency of bioretention systems.

Bioretention systems effectively capture rubber particles and other microplastics in stormwater runoff. However, it is uncertain whether long-term particle accumulation affects pollutant removal efficacy. This study investigated the impact of various concentrations of ethylene-propylene-diene-monomer (EPDM) particles (0, 50, 100, and 400 mg/L) on bioretention system nitrogen removal performance. The input of EPDM during short-duration (2 h) rainfall favored the removal of nitrogen, and the total nitrogen effluent concentration of the bioretention system with EPDM was reduced by 0.59-1.52 mg/L compared with that of the system without EPDM. In addition, the input of EPDM reduced the negative effects of drought. During long-duration (24 h) rainfall, higher concentrations of EPDM led to lower nitrate-nitrogen concentrations in the effluent. The bioretention system with EPDM required less time for nitrate-nitrogen removal to reach 50% than that without EPDM input. Microbial community analysis showed that EPDM increased the relative total abundance of denitrifying bacteria (such as Dechloromonas, Zoogloea, Ramlibacter, and Aeromonas) by 7.25-10.26%, which improved the denitrification capacity of the system.

Effect of Palm Oil Mill Effluent (Pome) Concentration and Soil Type on the Growth of Oil Palm (Elaeis guinensis Jacq) in Pre-Nursery

The place of research was carried out at Educational and Research Garden of the STIPER Agricultural Institute which is located in Maguwoharjo Village, Depok District, Sleman Regency, Yogyakarta, Indonesia. The research location is located 118 meters above sea level. This research was conducted between March to June 2024. Two components make up the factorial experiment used in the Complete Randomized Design (CRD). The soil type had three levels: A1 = latosol soil, A2 = regusol soil, and A3 = grumusol soil, was the first factor. Palm Oil Mill Effluent (POME) concentration was the second factor. It was consisted into four levels: X1 was the control (NPK fertilizer), X2 was 150 ml per polybag, X3 was 300 ml per polybag, and X4 was 450 ml per polybag. So there were 12 treatment combinations (3 x 4 = 12) with 4 repetitions, so all the experiment 48 plants. Analysis of variance (ANOVA) was applied at the significant level of 5% to check the observation data. Duncan's Multiple Range Test (DMRT) was then used at a noticeable 5% level if there was significant difference. The weight parameters of fresh roots and the amount of chlorophyll in the leaves are influenced by the interaction of the soil and POME concentration. The composition, regusol soil and POME 450 ml/polybag provide an optimal combination of treatments. The type of soil has an impact on the weight of fresh and dry crowns, the number of leaves, the chlorophyll content in the leaves, the volume of roots, and the height of the plant. The best type of soil is regusol soil. Plant height, root volume, fresh and dry crown weight, and leaf chlorophyll content are all affected by POME concentration. The concentration of POME 450 ml/polybag showed the best results.

Measurement of Acrylamido Tertiary Butyl Sulfonate Polymer Retention on Limestone by Three Methods Under Varying Temperature and Oil Presence

Summary Polymer retention poses a significant challenge in polymer flooding applications, emphasizing the importance of accurately determining retention levels for successful project design. In carbonate reservoirs of the Middle East, where temperatures exceed 90°C, conducting adsorption tests under similar temperature conditions becomes crucial for the precise determination of adsorption values. The choice of analytical method potentially impacts the accuracy of retention measurements from effluent analysis. This study investigates the effect of temperature on the performance of a polymer, specifically its rheological behavior and retention. Rheological and polymer flooding experiments were carried out using an acrylamido tertiary butyl sulfonate (ATBS)-based polymer in formation water (167,114 ppm) at different temperatures (25°C, 60°C, and 90°C) with required oxygen control measures. Dynamic polymer retention was conducted in both the absence of oil (single-phase tests) and the presence of oil (two-phase tests). In addition, different analytical techniques were evaluated, including viscosity measurements, ultraviolet (UV)-visible spectroscopy, and total organic carbon-total nitrogen (TOC-TN) analysis, to determine the most accurate method for measuring the polymer concentration with the least associated uncertainty. Furthermore, the study investigates the effects of these uncertainties on the final dynamic polymer retention values by applying the propagation of error theory. The effluent polymer concentration was determined using viscosity correlation, UV spectrometry, and TOC-TN analysis, all of which were reliable methods with coefficient of determination (R2) values of ~0.99. The study analyzed the effects of flow through porous media and backpressure regulator on polymer degradation. The results showed that the degradation rates were around 2% for flow through porous media and 16% for mechanical degradation due to the backpressure regulator for all temperature conditions. For the effluent sample, the concentration of polymer was lower when using the viscosity method due to polymer degradation. However, the TOC-TN and UV methods were unaffected as they measured the TN and absorbance at a specific wavelength, respectively. Therefore, all viscosity results were corrected for polymer degradation effects in all tests. During the two-phase coreflooding experiment conducted at 25°C, the accuracy of the UV spectrometry and viscosity measurements was affected by the presence of oil, rendering these methods unsuitable. However, the TOC-TN measurements were able to determine effluent polymer concentration and, subsequently, the retention value. Moreover, the use of glycerin preflush to inhibit oil production during polymer injection in the two-phase studies showed that all three methods were appropriate. The error range was obtained using the propagation of error theory for all the methods. Accordingly, it was noted that the temperature did not affect the dynamic retention values in both single-phase and two-phase conditions. The findings of this study highlight that when adequate oxygen control measures are implemented, the temperature does not exhibit a statistically significant impact on the retention of the ATBS-based polymer under investigation. Furthermore, TOC-TN has been identified as the optimal analytical method due to its minimal uncertainties and ease of measuring polymer concentration under varying experimental conditions.

Biofilm characterization and dynamic simulation of advanced rope media reactor for the treatment of primary effluent.

Biofilm modeling is inherently complex, often requiring multiple assumptions and simplifications. In biofilm modeling, default or literature-based values in biofilm systems are usually used to estimate biofilm parameters, including boundary layer, biofilm density, thickness, attachment, and detachment rates. This study aimed to characterize and model the biofilm of a specific rope-type fixed media system, removing carbon and total inorganic nitrogen, coupled with sensitivity analysis. Among the five model parameters, the sensitivity analysis of this study showed that boundary layer thickness is the most influential parameter for predicting effluent ammonia and nitrate concentrations, and biofilm density is most sensitive with respect to effluent chemical oxygen demand (COD). The least sensitive parameter is the detachment rate. Based on the calculated mean absolute error (MAE) and root mean squared error (RMSE), the calibrated BioCord fixed-film reactor (BFFR) model accurately predicted effluent ammonium and dissolved oxygen (DO) in the continuously aerated bench-scale reactor (R1) and failed to predict well in the intermittently aerated bench-scale reactor (R2). RMSE values calculated for NH3-N and DO in R1 are 0.95 and 0.53 mg/L, respectively. In the BioCord pilot plant's case, ammonium-N predicted by the model fit the measured values well, while it overpredicted DO concentrations. PRACTITIONER POINTS: Fixed biofilm BioCord reactors were studied for primary effluent treatment. A methodology was developed to characterize biofilms. Boundary layer thickness is the most influential parameter for predicting effluent ammonia and nitrate concentrations. Biofilm density is the most sensitive parameter with respect to effluent COD. The calibrated BFFR model can predict effluent ammonium, nitrite, and nitrate-nitrogen.

Performance evaluation of a brewery wastewater treatment plant: A case of Heineken Brewery, Addis Ababa, Ethiopia

Untreated wastewater from the brewing industry poses significant environmental risks due to its high organic content. Therefore, this study evaluates the wastewater treatment system at Heineken Brewery in Addis Ababa, Ethiopia. Key parameters analyzed include COD, BOD₅, TSS, pH, ammonia (NH₃), total nitrogen (TN), total phosphorus (TP), electrical conductivity (EC), temperature, turbidity, and volatile fatty acids (VFA). These parameters were analyzed following the procedures of the American Public Health Association's standard. The treatment system demonstrated notable efficiency, with influent temperature decreasing from 29.37 °C to 25.35 °C, remaining well below the acceptable limit of 40 °C. The pH dropped from a mean of 9.3 to 7.5, aligning with the acceptable range of 6–9. COD and BOD₅ were significantly reduced by 97.2 %, achieving levels well below discharge limits of 250 mg/L and 60 mg/L, respectively. TSS levels decreased by 95.7 %, with a mean of 32.3 mg/L. However, TP and TN removal efficiencies were lower at 49.4 % and 57.6 %, respectively, with TP slightly exceeding the limit of 5 mg/L. The system effectively reduced VFA by 94.3 % and turbidity by 71.5 %. While parameters such as pH, temperature, TN, NH₄-N, and EC were within acceptable limits, the high nutrient concentrations in the final effluent indicate potential environmental contamination if discharged untreated. Overall, while the treatment plant shows commendable pollutant removal efficiency, further optimization is needed for improved nutrient management.