Suspended Organic Matter Research Articles

Oil and gas field water not only contains low concentrations of lithium but also a lot of suspended matter, inorganic salt, and organic matter. Both inorganic ions and organic substances influence the extraction of lithium. To improve the extraction efficiency of low-concentration lithium in oil and gas field water, the effects of Na+, K+, Ca2+, Mg2+, Cl−, Br−, SO42−, NO3−, and organic substances on the extraction efficiency of lithium were studied. The results showed that Na+ can promote the extraction of lithium to a certain extent, and lithium ions competed with K+ for extraction; however, the separation coefficient remained more than 13. Ca2+ and Mg2+ have a significant influence on the extraction of lithium and should be removed prior to extraction. Cl−, SO42−, and NO3− have little influence on the extraction solution of lithium. Among the organic components, a high concentration of long-chain alkane has a certain effect on the extraction efficiency of lithium, while other substances have little effect. On this basis, the first step for precipitating impurity ions and the second step for solvent extraction of lithium were established. After removing the impurity ions, the extraction efficiency of lithium can reach over 90%. Taking 15L of oil and gas field water as the research object, after extraction, back extraction, concentration, depth impurities removal by extraction, and precipitation drying, the purity of the lithium carbonate product can be achieved at 99.28%. This study can provide technical support for the efficient extraction of low-concentration lithium from oil and gas field water.

Abstract Bioavailable nitrogen governs ocean productivity and carbon fixation by regulating phytoplankton growth and community composition. Nitrogen input primarily results from fixation, while denitrification and anammox remove bioavailable nitrogen in oxygen‐depleted conditions. Traditionally considered limited to highly suboxic (i.e., <5 μM) waters, recent studies suggest that fixed‐nitrogen removal processes may extend beyond, elevating global nitrogen loss estimates. This study directly quantifies fixed‐nitrogen loss across oxygen gradients (from 140 to 32 μM) along the Estuary and Gulf of St. Lawrence using N cycle tracers (, , and ). Notably, we observe significant production when ambient concentrations fall below a threshold value of 58.9 ± 1.1 μM, including potential water column fixed‐nitrogen removal processes above suboxia. We hypothesis that ambient deoxygenation eases the formation of suboxic microareas in suspended organic matter. Benthic production remains unaffected under intensifying water column deoxygenation from 50 down to 32 μM, but the contribution of produced through nitrification in the sediment to denitrification diminishes as deoxygenation intensifies. Combined, water column and benthic fixed‐nitrogen removal processes drive anomalies and strong deficiency in bottom waters. Additionally, the observed threshold also triggers production. Overall, our study highlights the profound impact of coastal ocean deoxygenation on nitrogen cycling, suggesting unexpected shifts even at ambient oxygen concentrations traditionally considered well above suboxic conditions.

The rapid expansion of informal settlements near South African water bodies has led to a significant decline in water quality. Runoff from inadequate sanitation and drainage systems contaminates rivers, wetlands and groundwater, posing risks to aquatic ecosystems and human health. Addressing these challenges requires innovative, low-cost solutions such as nature-based infrastructure (NBI), which can be implemented in a decentralised manner. Among these, constructed wetlands (CWs) stand out as potentially effective NBI solutions, providing a sustainable approach for water treatment without relying on additional chemicals or energy. They can remove pollutants such as total suspended solids (TSS), organic matter, nutrients and heavy metals, although their efficacy depends on site-specific conditions and water quality characteristics. Despite their potential, research on field-scale CWs for treating surface water polluted by informal settlements remains limited. This study evaluates the performance of a field-scale CW, incorporating vegetated and non-vegetated cells, to treat surface water from an informal settlement. Rigorous monitoring and operational protocols were implemented to optimise CW efficiency and enhance water quality for irrigation and environmental discharge. The CW effectively reduced ammonia nitrogen (NH₃-N), orthophosphate (PO₄³⁻) and Escherichia coli (E. coli) concentrations by up to 84%, 75% and 100%, respectively. The treated water met standards for irrigation reuse, although additional disinfection was required in some cases. While the findings highlight CWs' potential, uncertainties persist about their sustained performance under fluctuating water quality and pollutant loads typical of informal settlement runoff. Further research is therefore needed to understand temporal water quality variations, optimise CW operation under peak pollutant loadings, and address emerging contaminants in surface waters affected by informal settlements.

Serpulids are an ecologically important group of sessile suspension feeders that play a key role in benthic-pelagic coupling by filtering and transforming suspended organic matter from the water column. Temperature is one of the main abiotic factors influencing marine ectotherm physiology and metabolic responses, including serpulids and their growth, survival and distribution patterns. Thus, the present study objective was to determine thermal acclimation effects on metabolic responses of two serpulid species-Spirobranchus spinosus and S. cf. corniculatus-distributed in the temperate Northern Pacific and tropical Eastern Pacific, respectively. Both adult tubeworm species were collected from the wild and acclimated for 30 days at different temperatures, directly affecting oxygen consumption (OCR) and ammonia excretion (AER) rates of both species. However, OCR decreased for warm-water species S. cf. corniculatus at 33°C. The O:N values of both species were low at all acclimation temperatures (0.5-3.9), indicating that individuals were using protein catabolism to obtain energy. The present study not only provides basic data on these two tubeworm species metabolic responses for the first time but also contributes to understanding how their metabolism is influenced by environmental changes (e.g., ocean warming), which may help assess their capacity to cope with climate change scenarios.

Nejayote (Nej), an effluent from nixtamalization process, has an alkaline pH and contains a high load of organic matter in suspension and dissolution, which makes it a highly polluting waste when discharged directly into the environment. However, the sustainable reuse of this effluent is relevant since it contains high-value compounds (ferulic acid (FA)) with appropriate activity for the ecological synthesis of silver nanoparticles (AgNPs). This study explores the synthesis of AgNPs using Nej as a reducing and stabilizing agent and evaluates the antibacterial effectiveness of AgNPs against Escherichia coli (E. coli). The AgNPs under study possess excellent optical (UV-Vis) and structural properties (XRD). HR-TEM images show predominantly spherical particles, with an average size of 20 nm. FTIR spectroscopy identified functional groups, including phenols and flavonoids, on the nanoparticle surface, acting as stabilizing agents. HPLC supports the existence of FA in the AgNPs. Biogenic AgNPs exhibit enhanced antibacterial activity due to the adsorption of these functional groups onto their surface, which contributes to bacterial membrane disruption. Finally, no hemolytic or cytotoxic activity was observed, suggesting that the AgNPs exert antimicrobial activity without potentially harmful doses (biocompatibility). The study highlights the potential of Nej as a sustainable source for use in nanoparticle synthesis, promoting the recycling of agro-industrial waste and the production of materials with technological applications.

Aquaculture effluents are a growing source of water pollution, releasing suspended solids, organic matter, nitrogen, and phosphorus into aquatic environments. Recirculating aquaculture systems (RASs) have emerged as a more sustainable solution, allowing water to be continuously treated and reused. Within RASs, coagulation–flocculation is a key treatment step due to its simplicity and effectiveness. Tannin-based coagulants have gained attention as natural alternatives to traditional chemical agents. Although natural coagulants have been studied in aquaculture, only a few works explore their use in continuous-flow systems. This study evaluates a chestnut shell-based (CS) coagulant applied in continuous mode for the post-treatment of aquaculture effluent. The performance of CS was compared with Tanfloc, aluminum sulfate, and ferric chloride in removing color and dissolved organic carbon (DOC). At natural pH (6.5) and 50 mg·L−1, CS and Tanfloc achieved color removal of 61.0% and 65.5%, respectively, outperforming chemical coagulants. For DOC, Tanfloc and chemical coagulants removed 45–50%, while CS removed 32%. All coagulants removed over 90% of phosphorus, but nitrogen removal was limited (30–40%). These results highlight the potential of tannin-derived coagulants, particularly from agro-industrial residues, as sustainable solutions for aquaculture wastewater treatment in continuous systems.

The expansion and development of aquaculture activities in the Tam Giang-Cau Hai lagoon system, including the Thuy Tu and Cau Hai lagoons, has generated waste that impacts the natural environment. This research focused on assessing the isotopic compositions of carbon and nitrogen in suspended organic matter within the aquaculture ponds and surrounding ecosystems of the Thuy Tu and Cau Hai lagoons. The isotopic fingerprints of organic carbon and nitrogen in suspended matter showed significant differences between the Thuy Tu and Cau Hai lagoons, depending on the sampling period (March and July). The ratio of particulate organic carbon to particulate nitrogen (POC/PN) in suspended matter indicated a substantial contribution from phytoplankton. A mixing model was applied to determine the impact of aquaculture waste on the Thuy Tu and Cau Hai lagoons. By quantifying the contributions of each carbon and nitrogen source, this study successfully evaluated the significant influence of artificial fertilizer source on both lagoons for the first time. Fertilizer contributions relating to aquaculture activities increased progressively with distance in Thuy Tu lagoon, while in the Cau Hai lagoon, the impact of fertilizers came from both aquaculture activities and agricultural production.

Industrial effluent contaminants include insoluble substances, heavy metals and organic and inorganic compounds. The textile industry has a hard time dealing with its waste because it contains a lot of different colours and chemicals. To treat industrial effluent, coagulation-flocculation is frequently employed due to its efficacy in removing suspended particles organic matter, turbidity and colour. Conversely, employing a chemical coagulant may result in significant costs and the production of considerable quantities of non-biodegradable waste and metallic byproducts in the treated water, both of which face contamination risks by pollutants and diseases. An environmentally sustainable, non-toxic and biodegradable alternative method under consideration of utilising natural coagulants derived from plants, namely papaya seed and date seed. This study uses different NaCl concentrations to see how well papaya seed and date seed work as natural coagulants in treating textile industry wastewater. NaCl was the solvent and distilled water was used to extract the natural coagulant. Chemical Oxygen Demand (COD), turbidity, ammonia nitrogen and pH were assessed to evaluate the textile wastewater sample's response to papaya and date seed purification. The experiment's findings indicate that papaya and date seeds possess exceptional coagulation properties. The optimum turbidity reduction efficiency for papaya seed was 61.48% when 30 ml of a 1.0 NaCl concentration solvent was utilised. On the other hand, date seed removed turbidity with an efficiency of 83.96% when 10 ml of a 1.0 NaCl solvent was utilised. Aside from that, 1.0M NaCl was found to be the most effective COD reduction solution for the Carica papaya seed, while 2.0M NaCl resulted in a 56.19% reduction for the date seed. In addition, 30 ml Carica papaya seed coagulant dosage containing 2.0M NaCl produced the most significant reduction in ammonia nitrogen (82.84%). Also, the dosage of 20 ml date seed coagulant containing 2.0M NaCl eliminated 43.33% of ammonia nitrogen. The study's findings illustrated the potential advantages of utilising papaya and date seeds as organic coagulants in the remediation of effluents from the textile industry.

Abstract Municipal wastewater treatment philosophy shall shift from the conventional energy‐ and chemical‐intensive approach to a more circular, energy self‐sufficient system aligned with Sustainable Development Goals (SDGs) 7, 9, 11, and 13. Direct membrane filtration (DMF) using ultrafiltration provides a low‐energy alternative for recovering organics, which are utilized for energy recovery through anaerobic digestion (AD). However, DMF faces challenges from membrane fouling and elevated dissolved organics in the permeate. To address these issues, this study implements biological contact tank pre‐treatment before DMF, with a short hydraulic retention time (HRT) of 60 min. This pre‐treatment selectively removes 62% of dissolved organics without compromising the recovery of suspended or colloidal organic matter and enhances permeate quality by 40% in terms of chemical oxygen demand (COD). The DMF system without pre‐treatment exhibits 1.84 times higher irreversible pore‐blocking membrane resistance, with higher foulant concentrations per membrane unit area (up to 2.54 times) and enzymatic activity (up to 3.04 times). The recovered organics undergo AD, yielding methane up to 336 ± 23 mL‐CH4/g‐VS, making the DMF system net energy positive. Life cycle assessment (LCA) reveals that the DMF system has lesser environmental impacts than the conventional system in 10 out of 18 impact categories.

A novel process-based model of horizontal subsurface flow constructed wetlands for simulation of emerging organic contaminants: Conceptualization and calibration of BIO_PORE_EOC.

A sustainable solution for aquaculture wastewater treatment: Evaluation of tannin-based and conventional coagulants.

Turbidity adalah ukuran dari tingkat kejernihan atau kekotoran air, yang disebabkan oleh partikel-partikel tersuspensi yang ada di dalamnya. Pengujian Turbidity dapat dilakukan melalui proses Jar test. Jar test adalah metode uji laboratorium yang digunakan dalam pengolahan air untuk menentukan dosis bahan kimia (seperti koagulan dan flokulan) yang optimal, dengan tujuan untuk menghilangkan partikel tersuspensi dan bahan organik yang menyebabkan kekeruhan dalam air. Dalam proses Jar test, terdapat tiga tahapan utama yang penting, yaitu koagulasi, flokulasi, dan sedimentasi. Ketiga tahapan ini merupakan langkah penting dalam menghilangkan partikel tersuspensi, bahan organik, dan kotoran lainnya dari air. Turbidity air pada konsentrasi optimum 90 ppm yang diperoleh setelah penambahan Alumunium Sulfat Al2(SO4)3 memenuhi standar kualitas air minum berdasarkan Permenkes RI No. 492/MENKES/X/2010 yang sesuai sistem manajemen baku mutu ISO 9001:2015 dan standar baku mutu air baku yang digunakan yaitu Peraturan Pemerintah RI No.22 Tahun 2021 tentang Penyelenggaraan Perlindungan dan Pengelolaan Lingkungan Hidup. Kata Kunci: Air, Turbidity, Jar test Abstract Turbidity is a measure of the level of clarity or dirtiness of water, caused by suspended particles in it. Turbidity testing can be done through the Jar test process. Jar test is a laboratory test method used in water treatment to determine the optimal dosage of chemicals (such as coagulants and flocculants), with the aim of removing suspended particles and organic matter that cause turbidity in water. In the Jar test process, there are three main stages that are important, namely coagulation, flocculation, and sedimentation. These three stages are important steps in removing suspended particles, organic matter, and other impurities from water. The turbidity of water at an optimum concentration of 90 ppm obtained after the addition of Aluminum Sulfate Al2(SO4)3 meets the drinking water quality standards based on the Regulation of the Minister of Health of the Republic of Indonesia No. 492/MENKES/X/2010 which is in accordance with the ISO 9001:2015 quality standard management system and the raw water quality standard used is Government Regulation of the Republic of Indonesia No. 22 of 2021 concerning the Implementation of Environmental Protection and Management. Keywords: Water, Turbidity, Jar test

Abstract Oxygen Deficient Zones (ODZs) are the largest pelagic sinks of N containing nutrients in the ocean. The offshore Eastern Tropical North Pacific (ETNP) ODZ has been shown to be limited by organic matter. We propose zooplankton/forage fish as a key source of particulate and dissolved organic matter for N2 production that has previously been ignored. We examined data sets from four cruises (April 2012, January 2017, April 2018, October 2019) at a station in the central ETNP. Backscattering data were used to determine zooplankton vertical migration depths (250–450 m, maximum at 270–280 m). Metazoan DNA concentrations, as measured by quantitative PCR, had a reproducible maximum at 270–280 m, confirming that these signals indicate the presence of zooplankton/forage fish. Additionally, a large maximum in sinking pteropod shells was found at 270 m, indicating that pteropods were part of the migrating community. While crustacean zooplankton have been shown to reduce respiration and excretion of ammonium under anoxia, we found intermittently measurable ammonium concentrations at 270 m. Here we show signatures consistent with organic matter of zooplankton/forage fish origin in the C:N and δ13C of suspended and sinking organic matter at the vertical migration depth that suggest transportation to these depths by migrating zooplankton/forage fish. Also coincident with the migration maximum was a reproducible‐between‐years maximum in the biological N2 gas, and a repeatable shoulder on the nitrite maximum, which suggest that the migrating zooplankton partially fuels N loss. Thus, zooplankton/forage fish appear to be one source of organic matter which can fuel N2 production in ODZs.

Bathymetric data are crucial for benthic monitoring in coastal areas but are traditionally obtained through costly and geographically limited acoustic methods. This study uses satellite-derived bathymetry (SDB) in the Eastern Mediterranean, focusing on the Cretan Sea in Greece. It explores how variations in water surface optical properties affect SDB models over four years (2019–2022), using Sentinel-2 satellite data. The research covers two areas with contrasting features: the Chania Gulf and the open waters around Chrissi Island. Three methodologies were tested: the band-ratio method, the linear-logarithmic method, and an inherent optical properties linear model. Significant spatiotemporal variations in the SDB models were found, due to seasonal changes in water surface properties, such as temperature and suspended organic materials. Linear optical properties-based methods performed best, achieving a mean RMSE close to 1 m, slightly outperforming the ratio-based method. The logarithmic method was less effective, with RMSE values ranging from 1.3 to 1.5 m. A preliminary Kalman filter (KF) analysis increased RMSE to the decimeter level. This study demonstrates the impact of water surface optical properties on SDB models. It highlights the value of SDB for cost-effective, high-resolution coastal mapping in complex coastlines like those in Greece.

The Sewon domestic wastewater treatment plant (WWTP) plays a crucial role as a domestic wastewater treatment unit in the densely populated areas of Yogyakarta. Domestic wastewater generally contains suspended solids, organic matter, pathogens, and nutrients. Uncontrolled management of domestic wastewater effluent can cause serious environmental impacts, such as the spread of diseases and a decrease in water quality that has the potential to hinder reuse. Sedimentation and eutrophication processes can also occur, further impacting the performance of wastewater treatment units. The phenomena and challenges that occur in WWTPs can be examined through mathematical modeling, especially dynamic models, to understand the relationship between waste components and the working mechanism of the wastewater treatment system. Numerical approaches, especially the finite difference method, play a significant role in solving the complexity of models that are difficult to solve using exact methods. This article presents a study based on field observations and analysis of relevant scientific literature, to identify various potentials and challenges in wastewater management, analyzed through mathematical model approaches and numerical techniques.

Monsoon variability plays a pivotal role in Malaysia's economy, yet research has overlooked its impact on chlorophyll-a distribution in the South China Sea. Our study addresses this gap, focusing on the monsoon's influence on chlorophyll-a levels in Malaysian waters, enhancing the understanding of regional marine ecosystems and their economic significance. The objective of this research is to examine the Northeast Monsoon (NEM) and Southwest Monsoon (SWM) influence on the variability of chlorophyll-a concentration distribution and its relation to the total number of fish landings in East Malaysia in the year 2019. To achieve this goal, MODIS data was utilized. Literature reviews have indicated that remote sensing wavelength reflectances at 443 and 555 nanometers were also employed to assess phytoplankton biomass and suspended sediment concentrations. An increase in the phytoplankton absorption coefficient at 443 nanometers, coupled with a higher backscattering constant for dissolved and detrital material, correlates with elevated phytoplankton biomass and suspended sediment concentrations. The investigation revealed significant variability in chlorophyll-a concentrations across monsoon seasons, with values peaking at 36.5 mg mˉ³ during the SWM, which contrasts markedly with the NEM. This influence of suspended sediment and organic matter may introduce bias to chlorophyll-a concentration measurement. Accordingly, an increase in the phytoplankton absorption constant at 443 nanometers, coupled with a higher backscattering coefficient for dissolved and detrital material, correlates with elevated phytoplankton biomass and suspended sediment concentrations. The investigation revealed significant variability in chlorophyll-a concentrations across monsoon seasons, with values peaking at 36.5 mg mˉ³ during the SWM, which contrasts markedly with the NEM. This variability underscores the profound impact of monsoon dynamics on chlorophyll-a distribution in East Malaysia, influencing both marine biomass and fishery yields. These findings suggest that different monsoon seasons lead to varying total fish landings in East Malaysia. Established on the observed differences in chlorophyll-a dispersion, remote sensing technology explains higher fish catches during the SWM than the NEM. This information is vital for fishers, as it aids in optimizing their operation and reducing overall costs.

The spatial distribution characteristics of nitrogen and phosphorus nutrients in cascade reservoirs in high-altitude regions are crucial for water quality management. Water samples were collected from 20 typical section points in the middle and upper reaches of the Heihe River. The research focused on the nutrient concentrations in the surface, middle, and bottom layers of the cascade reservoirs. Nutrient distribution characteristics in the reservoirs were analyzed using both longitudinal and vertical sampling. The results showed significant depth-dependent variations in nitrogen and phosphorus concentrations, influenced by hydrodynamic processes, sediment dynamics, and nutrient cycling. The overall trend for TP, and TN concentrations at the selected sampling points was consistent, with bottom-layer concentrations being significantly higher than those in the surface layer. concentration was highest in the middle layer and lowest in the bottom layer, while the CODMn was highest in the surface water and lowest in the middle layer. The primary factors affecting these spatial distribution characteristics include the types and quantities of microorganisms and biological communities at different water depths, water movement and convection, sedimentation rates of suspended particles and organic matter, as well as human activities.

Membrane bioreactor (MBR) technology has gained significant attention in the realm of wastewater treatment. Using membrane bioreactors in wastewater treatment provides numerous advantages, including high-quality effluent, space efficiency, higher treatment performance, flexibility, reduced sludge production, improved process control, and environmental benefits. Membrane fouling, on the other hand, continues to be a major issue, resulting in higher operational costs, a shorter membrane lifespan, and frequent maintenance requirements. Fouling is produced by deposits of suspended particles, colloids, bacteria, and organic materials on the membrane's surface or within its pores, resulting in decreased permeability. This review critically explores the fouling mechanisms in MBR systems. This review provides a comprehensive analysis of membrane fouling in the Membrane Bioreactor (MBR), focusing on the mechanisms that lead to fouling, its impacts on system performance, and the state-of-the-art techniques employed to control fouling. Membrane fouling is one of the most critical challenges in the operation of MBRs, significantly affecting their efficiency and operational costs. This paper provides an overview of fouling phenomena in MBR systems while also highlighting innovative techniques to improve membrane performance and longevity.

As the scale of shrimp aquaculture continues to expand, the environmental impacts of shrimp effluents have become increasingly severe. The purification of aquaculture effluents can no longer be overlooked. Effectively reducing the discharge of aquaculture wastewater and mitigating its potential pollution risks to the surrounding aquatic ecological environment are key issues that need to be addressed to promote the industry’s development towards a greener, more environmentally friendly, and sustainable path. This study explored the purification effect of the integration of tilapia and Spirulina on tail water from a zero-water-exchange aquaculture of whiteleg shrimp (Litopenaeus vannamei) in seawater, with the aim of assessing the growth performance of tilapia and the efficacy of the fish–algae integration in purifying tail water from the perspective of tail water resource utilisation. The study found that the removal rates of the biofloc sedimentation volume and total suspended particle concentration in the fish–algae group were 42.6% and 29.6%, respectively. The removal rates of phosphate and total phosphorus in the fish–algae group were 26.3% and 20.8%, respectively. Research indicates that tilapia effectively removes suspended organic matter from water. Introducing Spirulina into this water body aids in the removal of soluble nitrogen and phosphorus from the effluent, and tilapia exhibit a favourable feeding response to Spirulina.

The most significant pollutant produced from agricultural industry in Kalimantan, Indonesia is Palm Oil Mill Effluent (POME). Due to the high levels of suspended particles and organic matter, POME has become a brownish color with high turbidity, color, chemical oxygen demand, and oil and grease content. To recycle the POME wastewater as clean water, these pollutants must be eliminated. In this study, we compare the effectiveness of hollow fiber (HF) and flat sheet (FS) membrane to remove total dissolved solid (TDS) and turbidity from POME with varied filtration pressure. HF and FS membrane were prepared from PVDF and nylon66 polymer, respectively. The PVDF HF membrane was modified using TiO2 and SBE (spent bleaching earth) to improve HF membrane properties to maintaining fouling. Meanwhile, FS membrane was added by pectin to increase the hydrophilic properties. Overall membrane’s morphology was determined by Scanning Electron Microscopy (SEM) to investigate the membrane structure. Both of HF and FS membrane were operated via ultrafiltration (UF) under cross flow system. The filtration pressures were varied at 1-3 bar and followed by flux and rejection evaluation. The results show both HF and FS membranes has stability flux. In addition, TDS rejection up to 25% while turbidity is excellent high over 95% for all membranes. The fabrication HF membrane has finger like-sponge structure and FS membrane exhibits sponge asymmetric structure. Overall, all membranes perform highest water flux (FS membrane) while highest rejection conducted by HF membrane for POME wastewater treatment.