Alkylbenzene Sulphonate Research Articles

A meta-analysis of the impact of water-solved pollutants on the protein content of Pistia stratiotes L.

Due to the high cost of conventional water cleaning procedures, an affordable alternative for developing countries is the use of Pistia stratiotes L. Although these plants adsorb toxic chemicals in their tissues, other studies report a high protein content in its biomass and propose to use it as a fodder or even for human consumption. Therefore, this study aimed to identify the impact of water-solved pollutants on the content of protein in the tissues of P. stratiotes through a meta-analysis of currently available literature. Scientific reports, which included the biochemical analysis of the species when exposed to pollutants in the growing media were retrieved. The statistical analysis identified that chromium, wastewater sludge from a sugar factory, fluoride and linear alkyl benzene sulphonate reduce the content of protein. On the contrary, metals such as copper and zinc showed a slight tendency to promote the accumulation of protein in the biomass. Only the use of municipal wastewater sludge consistently promoted the increase of protein. Since most pollutants reduced the protein content and others also pose a bioaccumulation risk, P. stratiotes is not recommended to be considered as a fodder or to be included in human diet without previously ensuring its chemical innocuity.

Biodegradation of linear alkylbenzene sulfonate contamination by pseudomonas aeruginosa isolates

Linear alkylbenzene sulphonate (LAS), a surfactant frequently incorporated into detergent formulations, typically ends up in wastewater treatment facilities after use. The present study aims to investigate the efficacy of bacteria isolated from Iraqi wastewater in removing LAS. This strain was identified as Pseudomonas aeruginosa by genetic analysis (16S rRNA). Three LAS concentrations (25, 50, and 100 mg/l) were employed in this investigation, along with three temperatures (30, 35, and 40 oC) and pH values (5, 7, 9). The LAS anionic surfactant demonstrated optimal biodegradation by Pseudomonas aeruginosa at a temperature of 30 °C and at pH levels of 7 and 9, with removal percentages of 93.76% and 90.4%, respectively, at a concentration of 25 mg/l of LAS. The study's findings demonstrated the possibility and importance of using aerobic biodegradation to remove LAS from actual effluents. This bacterium is useful for bioremediation because of its capacity to break down LAS.

Quantification of linear alkylbenzene sulphonates in complex sludge samples: Influence of matrix effects in calibration methods

Linear Alkylbenzene Sulfonates (LAS) are among the priority organic pollutants in sludge owing to their high concentrations, due to its use as a major cleaning agent (surfactant) in laundry detergents and household cleaning products, and to the concentration limits of 2,600 mg/kg outlined in the EU directive draft for land application of sludge. In this work, a method has been optimized and validated for the accurate quantification of LAS homologues C10-C13 in different types of samples in the sludge treatment and disposal process including primary, secondary, and digested sludge, compost, and soil. The type of matrix had a significant impact on the method’s validation process, resulting in the need of the use of distinct dilution factors for each matrix. Overall, the procedure propose involves a cost-effective and user-friendly technique that combines both extraction and clean-up in a single step (ultrasound-assisted extraction and dispersive solid phase extraction). Analytical determination is conducted using liquid chromatography-tandem mass spectrometry. The method demonstrated excellent accuracy (relative recoveries exceeding 84.5 % across all types of sludge samples) and the limit of quantification enables the measurement of LAS concentrations up to 1000 times lower than the concentration limits stipulated in the EU directive draft. For an accurate quantification, three calibration approaches were tested (external calibration, standard addition, and matrix-matched calibration). Standard addition was the preferred method for quantitative analysis. It helps mitigate matrix effects that could otherwise distort the accuracy of analyte measurements, making it crucial for quality control, especially in monitoring applications where matrix effects may introduce bias into concentration calculations.

A comparative study of surfactant distribution and fate (western and eastern) Egyptian Mediterranean coasts focusing on its environmental toxicity

One of the most difficult-to-manage new contaminants constantly released into the environment is linear alkylbenzene sulphonate (LAS), an anionic surfactant. Significant volumes of LAS are received by the Mediterranean coast of Egypt. The current study is a comprehensive assessment of the environmental fate of the LAS 1505 km off the Mediterranean coast of Egypt in the fall of 2023 in order to track its geographic spread and eventual demise in the water column. Critical analysis of LAS revealed that it is vertically distributed in various ways according to sources, uses, production amounts, and salinity levels. The vertical variation of LAS can be explained by its amphiphilic structure. A significant increase in surfactant concentration (>300 μg/L) was recorded in 66% and 43% of the total samples, ranging from 301.128 to 455.36 and from 304.556 to 486.135 for the western and eastern sides along the Egyptian Mediterranean coast, respectively. Evaluation of the average acute and chronic risk quotient (RQ) along the investigated locations revealed that fish were the most susceptible to LAS in both long and short exposure periods. The presented results also indicated significant LAS toxicity to three trophic levels (RQ values > 1). LAS toxicity to marine organisms was greater in the western than in eastern coastal regions according to acute and chronic mixture risk characterization ratios (RCRmix). The three trophic levels in the study area had the following order of acute relative contribution (RC) to LAS toxicity: fish > invertebrates > algae. The ANOVA test results showed that in both the western and eastern regions, LAS varied significantly (p < 0.05) with salinity (1.04E-60 and 5.44E-42) and depth (6.02E-65 and 1.59E-47), respectively. In addition, a significant difference was observed using the ANOVA test between the eastern and western regions of the Egyptian Mediterranean coast.

Synergistic Combination of Carbohydrate Polymer with Conventional Active Materials for Detergent Formulations

Novel ecofriendly polymeric surfactant based on Sorbitol and Maleic anhydride has been synthesized and used successfully in detergent composition. Sorbitol is obtained majorly as a vegetable product. In present research work a small quantity of Maleic anhydride and Benzoic acid along with major quantity of Sorbitol has been used in synthesis of polymer. The mole ratio of ingredients and cooking schedule has been standardized to get desired molecular weight, HLB ratio and surfactant properties. Powder detergents have been formulated based on these novel polymer and conventional active ingredients such as alpha olefin sulphonate, sodium lauryl sulphate. And linear alkyl benzene sulphonate. This synergistic combination of novel polymer has been used as a 60 to 80% replacement of conventional linear alkyl benzene sulphonate in detergent powder formulation. The preparation of this polymer is ecofriendly and has a potential for commercial use as an ecofriendly detergent in powder form. The surface tension, foam height, % detergency and stain removing characteristics have been evaluated and compared with commercially available powder detergent sample. The petroleum resources are soaring in price and their replacement with novel polymer of vegetable origin will certainly promote the cause of Green Chemistry and Green Environment. Key word: - Novel polymer, Sorbitol, Detergents, Surfactants, Maleic anhydride, Synergistic combination. HLB- Hydrophilic–lipophilic balance.

Mutagenicity Assessment of Homologous Series of Methyl Ester Sulphonates (MES) Using the Bacterial Reverse Mutation (Ames) Test.

Methyl ester sulphonate (MES) is an anionic surfactant that is suitable to be used as an active ingredient in household products. Four palm-based MES compounds with various carbon chains, namely C12, C14, C16 and C16/18 MES, were assayed by the in vitro bacterial reverse mutation (Ames) test in the Salmonella typhimurium strains TA98, TA100, TA1535, and TA1537 and the Escherichia coli strain WP2 uvrA, with the aim of establishing the safety data of the compounds, specifically their mutagenicity. The test was also carried out on linear alkylbenzene sulphonate (LAS) for comparison. The plate incorporation method was conducted according to the Organization for Economic Cooperation and Development (OECD) Test Guideline 471. All compounds were tested at five analysable non-cytotoxic concentrations, varying from .001mg/plate to 5mg/plate, with and without S-9 metabolic activation. All tested concentrations showed no significant increase in the number of revertant colonies compared to revertant colonies of the negative control. The Ames test indicated that each concentration of C12, C14, C16, C16/18 MES, and LAS used in this study induced neither base-pair substitutions nor frame-shift mutations in the S. typhimurium strains TA98, TA100, TA1535, and TA1537 and the E. coli strain WP2 uvrA. The results showed that C12, C14, C16 and C16/18 MES have no potential mutagenic properties in the presence and absence of S-9 metabolic activation, similarly to LAS. Therefore, the MES is safe to be used as an alternative to petroleum-based surfactants for household cleaning products.

Unveiling the origin, fate, and remedial approaches for surfactants in sewage-fed foaming urban (Bellandur) Lake

Foam formation in surface water bodies has become a global phenomenon, but the solutions to this crisis are often insufficient. Foam formation in water bodies is attributed to surfactants and requires a comprehensive assessment of various sources of surfactants to evolve mitigation strategies. The study is focused on thoroughly analyzing surfactants in the water and foam fractions of a large waterbody in Bangalore (India) spanning around 1000 acres (400 ha), which has been foaming for two decades. Results revealed that the key surfactants originate predominantly from anthropogenic sources with a small component emerging from naturogenic sources. Anthropogenic surfactants were found to be predominant (96.5%), with linear alkylbenzene sulphonates (LAS) of various C-chain lengths 12–20 being the most prevalent. Naturogenic surfactants derived from bacterial genera Pseudomonas exhibited significant microbial diversity, accounting for over 19% of total bacterial population in both the water and organic sediments of the lake. Modelling studies and field validation efforts were carried out to understand the fate of LAS in the foaming lake. The results indicated that these surfactants donot degrade under the prevailing conditions and timeframe as wastewater traverses through the lake, and their presence was also observed in the organic sludge sediment. Modeling the underlying processes revealed that a minimum dissolved oxygen (DO) concentration of 3.5 mg/l enables the degradation of over 90% of surfactants within the residence time of 8–10 days in Lake. Additionally, the process of desludging could contribute to an additional increase to the overall efficiency of surfactant removal, simultaneously removing legacy sorbed surfactants to sediments.

Studi Efektivitas Koagulan Kitosan-Kapur Dalam Menurunkan COD, MBAS dan Fosfat pada Limbah Laundry

Abstract. Environmental pollution that is often encountered in daily life that comes from laundry waste. Laundry waste includes pollutants or substances that pollute the environment because in it there is a substance called linear alkylbenzene sulphonate (LAS). LAS is a detergent that is classified as hard to brake down by microorganisms (non-biodegradable) so that it can cause environmental pollution. One method that is often used in laundry wastewater treatment is coagulation using chitosan and lime as a coagulant. The purpose of this study was to analyze the efficiency and effectiveness in reducing pollutant levels in laundry waste using chitosan-lime coagulant. This study used a completely randomized design with 200 mg/L chitosan and 0.1-0.5 g lime. The test parameters used were COD, MBAS, and phosphate. Data were analyzed using calculation of efficiency and effectiveness of reduction, linear regression, and one-way ANOVA test. The results showed that under the best conditions, chitosan 200 mg/L and lime as much as 3.5 g resulted in a reduction efficiency of 68.52%, 9.15%, and 92.44%. Chitosan-lime is effective in reducing MBAS and phosphate levels to quality standard, but chitosan-lime coagulant is less effective in reducing COD levels because it still exceeds the the established quality standards

Toxic Effect of Anionic Surfactants on Freshwater Sponge Lubomirskia baikalensis and Its Endosymbiotic Microalgae Chlorella sp.

A number of reports on sponge diseases, including from Lake Baikal, have increased dramatically all over the world in recent years. Herewith, there are various hypotheses for sponge mortality. Lubomirskia baikalensis (phylum Porifera, order Spongillida) is a unique endemic freshwater sponge of Lake Baikal that contains a complex community of eukaryotic and prokaryotic endosymbiotic microorganisms. In this work, we present the first results for the effect of anionic surfactants viz. linear alkylbenzene sulphonates (LAS) at low 10 and 20 µg L−1 concentrations on Baikal sponge species and their symbiotic community as an experimental model. A new toxicity test protocol under conditions close to natural is proposed. It uses the sponge amoebocytes called as SA1-cells, which contain eukaryotic green microalgae Chlorella sp. These SA1-cells are shown to be representative indicator in assessing the impact of anionic surfactants. The acute toxic effect resulted in 97–100% sponge cell death in less than 48 h, as well as 100% symbiotic microalgae Chlorella sp. death over 72 h was noted under LAS solution (20 μg L−1) exposure during in vivo experiments. This includes the cell membrane fatty acid changes, change in the cell sizes, cell swelling, and lysis. Long term exposure to LAS solution (10 μg L−1) reflected in cellular stress (oxidative stress) and accompanied by malondialdehyde formation (0.16–2.0 μg g−1 of dry weight) during 14-day exposure was noted. Oxidative stress and mortality of L. baikalensis are associated with their low antioxidant activity. Trolox-equivalent antioxidant capacity (TEAC) found in the range from 0.00031 to 0.00077 Trolox equivalents for these freshwater sponges.

Purification of domestic laundry wastewater in an integrated treatment system consists of coagulation and ultrafiltration membrane process

An integrated unit to purify and reuse domestic laundry wastewater consisting of coagulation, sand filtration, carbon adsorption, and ultrafiltration process is developed. Chitosan and Ameztreat 102 polyamine were used as coagulants and their treatability was measured by color, turbidity and concentration of Linear Alkylbenzene Sulphonates (LAS) at various operation conditions. As a result of the trial studies, the maximum removal efficiency was attained as (i) for Chitosan- 98.2% color, 99.3% turbidity, 100% LAS removal efficiency; (ii) for Polyamine-88% color, 99% turbidity, 100% LAS. The transport mechanism of the pollutant towards the coagulant was described using kinetic models. The thickener area calculated is 0.2436 m2 for the flow rate of 100 L/h by Kynch theory. The results were recommended that the laundry wastewater be efficiently treated in the proposed treatment train and could be reused effectively.

Nitrogen removal by Rhodococcus sp. SY24 under linear alkylbenzene sulphonate stress: Carbon source metabolism activity, kinetics, and optimum culture conditions

Artificial intervention combined with stress acclimation was used to screen a heterotrophic nitrifying-aerobic denitrifying (HN-AD) bacterial, strain Rhodococcus SY24, resistant to linear alkylbenzenesulfonic acid (LAS) stress. When LAS was<15 mg/L, strain SY24 performed better cell growth and carbon source metabolism activity. The maximum nitrification and denitrification rates of SY24 under LAS stress could reach 1.18 mg/L/h and 1.05 mg/L/h, respectively, which were 13.80 % and 8.81 % higher than those of the original strain CPZ24. Higher LAS tolerance was seen in the functional genes (amoA, nxrA, napA, narG, nirK, nirS, norB, and nosZ). Response surface modeling revealed that 2 mg/L LAS, sodium succinate as a carbon source, 190 rams, and carbon/nitrogen 11 were the ideal culture conditions for SY24 to nitrogen removal under the LAS environment. This study offered a new screening strategy for the functional species, and strain SY24 showed significant LAS tolerance and HN-AD potential.

Linear Alkylbenzene Sulphonate (LAS) in Nile delta lagoon and its effects on hematological and biochemical parameters in Nile Tilapia, Oreochromis niloticus

ABSTRACT The primary goal of this study is to assess the effects of detergent residues; Linear alkylbenzene sulphonate (LAS) on hematological and biochemical parameters in Nile Tilapia, Oreochromis niloticus, in Burullus and Edku lagoon water. Fish from Burullus and Edku lagoons had lower hemoglobin, hematocrit, red blood cells (RBC), platelet count, and total serum proteins than Nile River fish, which served as a control site. The number of WBC count, serum aspartate transaminase (AST), alanine transaminase (ALT), total lipids, cholesterol, and triglycerides were significantly increased in Burullus and Edku lagoons compared to Nile River.

Surfactant pollution, an emerging threat to ecosystem: Approaches for effective bacterial degradation

The use of surfactants in households and industries is inevitable and so is their discharge into the environment, especially into the water bodies as effluents. Being surface-active agents, their utilization is mostly seen in soaps, detergents, personal care products, emulsifiers, wetting agents, etc. Anionic surfactants are the most used class. These surfactants are responsible for the foam and froth in the water bodies and cause potential adverse effects to both biotic and abiotic components of the ecosystem. Surfactants are capable of penetrating the cell membrane and thus cause toxicity to living organisms. Accumulation of these compounds has been known to cause significant gill damage and loss of sight in fish. Alteration of physiological and biochemical parameters of water decreases the amount of dissolved oxygen and thus affecting the entire ecosystem. Microbes utilizing surfactants as substrates for energy form the basis of the biodegradation of these compounds. The main organisms for surfactant biodegradation, both in sewage and natural waters, are bacteria. Several Pseudomonas and Bacillus spp. have shown efficient degradation of anionic surfactants namely: sodium dodecyl sulphate (SDS), linear alkylbenzene sulphonate (LAS), sodium dodecylbenzenesulphonate (SDBS). Also, several microbial consortia constituting Alcaligenes spp., Citrobacter spp., etc. have shown efficacy in the degradation of surfactants. The biodegradation efficiency studies of these microbes/microbial consortia would be of immense help in formulating better solutions for the bioremediation of surfactants and help to reduce their potential environmental hazards.

Effect of individual or combined physical and chemical factors on the anaerobic biodegradation of linear alkylbenzene sulphonate

The effect of six important factors on the anaerobic biodegradation of linear alkylbenzene sulphonate (LAS) was evaluated using a response surface methodology. The factors were: (i) co-substrate concentration (CC), (ii) contact time between LAS and microorganisms, (iii) temperature, (iv) hardness, (v) pH, and (vi) LAS source. The results showed that individually or combined, CC with chemical oxygen demand (COD) ≤50 mg L−1 was the factor that mostly favoured LAS biodegradation; whereas at COD >50 mg L−1, adsorption to sludge and solubilisation in the aqueous medium were favoured. Two-factor interactions promoted the highest percentages of biodegradation (45–52%), adsorption (43–45%), and solubilisation (18–25%). The three-factor interactions resulted in small percentage increases of up to 11%, 5%, and 13% for biodegradation, adsorption, and solubilisation, respectively, compared to those of two-factor interactions. The interactions of four, five, and six factors resulted in a non-significant effect on LAS biodegradation, adsorption, and solubilisation, with percentages close to those quantified for the two- and three-factor interactions. Concentrations of up to 30 mg LAS L−1 did not significantly affect the COD removal efficiency (74–88%) from the medium. These values are commonly obtained in full-scale anaerobic systems used to treat domestic sewage.

Process simulation and optimization of dodecyl benzene sulfonic acid production plant

The aim of work is to design sulfonating plant on the basis of a hydrophilic sulfonate head-group and a hydrophobic alkyl benzene tail-group reaction mechanism, study of kinetics and thermodynamics followed by a steady-state simulation for the process was done by ASPEN HYSYS (V8.8) through using Peng-Robinson fluid package. Then heat integration of the process, done by using Aspen Energy Analyzer and studies of the influence parameters on the simulated process of dodecyl benzene sulfonic acid. Alkyl benzene sulphonate is produced due to the sulphonation reaction of an alkylbenzene (LAB) plus a sulphonating agent in a falling film sulphonator to produce sulfonic acid (LABSA).The modeling of dodecyl benzene sulfonic acid plant depends on : Air drying, Sulphur melting and proportioning, Sulphur combustion and SO3 production, Film sulfonation. Dodecyl benzene sulfonic acid production rate is influenced by changing of the following factors: the sulfur molar flow rate, molar flow rate of air and pressure of dodecyl benzene, the results of optimization shows that : The optimum operating Molar flow rate of sulfur is lies in the range of [3:3.5] Kg.mol/h, The optimum operating Molar flow rate of Air is 25 Kg.mol/h, The optimum operating Molar flow rate of Dodecyl Benzene is 3.1 Kg.mol/h and The optimum operating Pressure of Dodecyl Benzene is 70 KPa. For heat integration, a proposed heat exchanger network is generated which made the process functional without external heating. Generation of the top 10 heat exchanger network (HEN) leads to: the best case scenario from the top 10 scenarios from the point of cost and also from the point of cooling and heating required was design (9). After heat integration, the total amount of cooling demand decreased from 912620.50 KJ/h to 890261.56 KJ/h and the total amount of heating demand decreased from 22358.94 KJ/h to 0KJ/h.

Optimization of surfactants formulations to stabilise proteases and amylases

The stability of amylase and protease with linear alkylbenzene sulphonate, ethoxylated fatty alcohol, alkylpolyglucoside, and silica microparticles was analysed. Protease showed first order deactivation finding the highest stability (deactivation energy 62.9 Kcal/mol) with linear alkylbenzene sulfonate/ethoxylated fatty alcohol/silica microparticles (10/10/1.5% w/w). Other surfactant formulations with ethoxylated fatty alcohol (20% w/w), alkylbenzene sulfonate/ethoxylated fatty alcohol (10/10% w/w) or linear alkylbenzene sulfonate/ethoxylated fatty alcohol/alkylpolyglucoside (10/5/5% w/w) also stabilised the protease.Linear alkylbenzene sulfonate deactivated the amylase. Linear alkylbenzene sulfonate/ethoxylated fatty alcohol/ alkylpolyglucoside (10/5/5% w/w) and linear alkylbenzene sulfonate/ethoxylated fatty alcohol/silica microparticles (10/10/1.5% w/w) minimised the amylase destabilisation. These formulations also showed high detergency.Alkylbenzene sulfonate promoted protein unfolding and reduced the enzymatic activity, and the non-ionic surfactants stabilised the enzymes, possibly because they interact harmlessly with the enzymes and avoid interaction with the anionic surfactants at the same binding sites. Optimised surfactant formulations were suggested for detergent formulation with amylase and protease.

Purification of bathing wastewater by double suspended layer fluidized bed reactor.

An external radial magnetic field and built-in stainless steel balls formed a magnetic suspended layer (MSL), as observed in this study. Under the condition of crossflow inflow, the flocculating agent and coagulant aids form a flocculated particles suspension layer (FPSL). Thus a double suspended fluidized bed reactor was constructed to treat bathing wastewater. A particle image velocimetry device was used to detect flow patterns and analyze the flocculation conditions. The results showed that under the condition of crossflow inflow, at the same time, the flooding water was 0.023-2.101 m3/h, and the dosage of poly aluminum chloride (PAC) and polyacrylic amide (PAM) was 90 mg/L and 1.5 mg/L, respectively, and removal rates of turbidity, chemical oxygen demand (CODCr) and linear alkylbenzene sulphonates (LAS) reached more than 99, 90, and 80%. Filtration, grid flocculation and particle interception were functions of the MSL. Meanwhile, the crossflow input created additional vortexes, increasing the likelihood of flocculation particle collision, improving the flocculation conditions and cleaning the MSL. The reactor aids in the development of the initial flocculated particles suspension layer, flocculation strengthening, chemical dosage reduction, effluent qualities improvement, and effluent stability maintenance.

Seasonal variation and impact of linear alkyl sulphonate (LAS) toxicity on Nile tilapia, Oreochromis niloticus in two Nile Delta Lagoons, Egypt

ABSTRACT The aim of the present study is to assess the accumulation of detergents residues; linear alkylbenzene sulphonate (LAS) in Burullus and Edku lagoons water, sediments, and muscles of Oreochromis niloticus and investigate hazards effect on fish. The data revealed a significant accumulation of LAS in Burullus and Edku water, sediments, and fish muscle compared to those recorded in the Nile River as a reference site. The study showed seasonal changes in the serum concentrations of superoxide dismutase (SOD), catalase (CAT) and glutathione reductase (GSH) for fish tilapia. The ANOVA test displayed a significant difference between different seasons (p ≤ .001). The results of the current study exhibited the effect of increasing the concentration of LAS on the fishes of Burullus and Edku lagoons. The study showed low concentrations of serum activity, CAT, SOD and GSH in comparison with the values in the control fish (Nile River fish). It causes oxidative stress, severe disruption, followed by cytotoxicity. In excessive production of reactive oxygen species, the serum of SOD, CAT and GSH are exploited for detoxification. Alterations in histopathological structure were observed in both Burullus, and Edku fish liver and gills compared to those in the control fish.

Effect of matrix composition on the flowability of spray-dried detergent powders

The flowability of spray-dried laundry detergent is important for manufacturing process performance and reliability, and product quality; it is strongly dependent on formulation. In this work, a detailed study of four model formulations provides fundamental understanding of the role of particle composition, and micro-structure, on spray-dried detergent powder flow behaviour. All spray-dried powders studied contained the sodium salt of linear alkylbenzene sulphonate (NaLAS) and sodium sulphate. However, their formulation varied depending on either the initial water content (30.0 or 63.0wt%) of the slurry or the addition of sodium silicate with molar-ratios of 1.6 and 2.35 SiO2:Na2O. The nil-silicate powder, made from low water content slurry, had the poorest flow characteristics. The addition of the silicate binder, significantly improved flowability, 2.35 ratio silicate, providing better flowability than 1.6 ratio. Remarkably, increasing the water content of the slurry also improved flowability significantly. Detail analysis showed that this was due to changes in composition and micro-structure of the composite matrix formed on drying the liquid components of the slurry, and that the improved flowability was due to improvements in mechanical strength of this matrix. These changes in mechanical robustness were significantly more important to the flowability than the powder shape.

Occurrence of organic micropollutants and heavy metals in the soil after the application of stabilized sewage sludge.

Stabilized sewage sludge could be used as a fertilizer in the soil because of nitrogen, phosphorus, and other micronutrition material to improve the properties of the soil. In this study, clover and fodder corn plants were planted in the soil to which stabilized sewage sludge was applied. The soil was analyzed and evaluated by collecting samples to determine changes in the application fields before plantation and one year after the harvest. To monitor changes in the soil and after the application of stabilized sludge to the soil, the stabilized sewage sludge was evaluated for the suitability of parameters such as heavy metals, halogenated organic compounds including adsorbable organic halogens (AOX), nonylphenol ethoxylates (NPE), polycyclic aromatic hydrocarbon compounds (PAH), polychlorinated biphenyls (PCB), di(2-ethylhexyl) phthalate (DEHP), linear alkylbenzene sulphonates (LAS), polychlorinated dibenzo-p-dioxins and dibenzo-p-furans (PCDD/F), and pathogens and other parameters containing organic matter (OM), pH, conductivity (EC), total nitrogen (TN), and total phosphorus (TP). After the sludge application, the heavy metal content increased, except for Zn. The application of stabilized sludge as a soil conditioner and humus caused a significant increase in the TN and TP content since the product increased the harvest that increased soil nutrition. After the sludge application to the soil, the concentration of organic micropollutants in the soil did not change. The concentration of AOX and PCDD/F in the soil increased by 141% and 125%, respectively.