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Industrial production operations generate huge amounts of heavy metals enriched sludge. Due to inadequate management and illegal disposal practices, this waste sludge can deteriorate human and environmental health. For sustainable environmental development and conserving human health, sludge should be recycled to recover the heavy metals and the treated sludge (with permissible or safe limits of heavy metals) should be used to improve the soil fertility and physical properties. Herein, a study is carried out to identify the optimum concentration of sulphuric acid (H2SO4) to remove copper (Cu), nickel (Ni) and chromium (Cr) from the waste sludge and the number of organic matter residues that remained after the acid digestion. Besides, the optimum pH to precipitate Cu, Ni, and dissolute the Cr in the form of metal hydroxide is determined. Acid digestion is done by using H2SO4 and precipitation is done by sodium hydroxide (NaOH). The heavy metals concentrations were determined through inductively coupled plasma-optical emission spectroscopy (ICP-OES). The result showed that the concentration of H2SO4 is significantly affecting the sludge organic content. The respective percentage of Cu, Ni and Cr removed by 30% of H2SO4 were 98.99, 99.27 and 97.22%. At pH 14, Cu, Ni and Cr precipitation to form metal hydroxide was the highest. About 4.01%, 23.75% and 13.93% of copper hydroxide, nickel hydroxide and chromium hydroxide are, respectively, precipitated out. However, slight dissolution occurred due to the nature solubility of metal hydroxide. [ABSTRACT FROM AUTHOR]

• Applied voltage and calcium addition increased biogas yield and CO 2 sequestration. • Wollastonite and CaCl 2 exhibited different CO 2 sequestration performances. • Wollastonite showed a better CO 2 sequestration effect with 2.22% CO 2 in biogas. • The contribution of chemical and biological CO 2 sequestration was clarified. The combination of microbial electrolytic cells and anaerobic digestion (MEC-AD) became an efficient method to improve CO 2 capture for waste sludge treatment. By adding CaCl 2 and wollastonite, the CO 2 sequestration effect with mineral carbonation under 0 V and 0.8 V was studied. The results showed that applied voltage could increase dissolved chemical oxygen demand (SCOD) degradation efficiency and biogas yield effectively. In addition, wollastonite and CaCl 2 exhibited different CO 2 sequestration performances due to different Ca2+ release characteristics. Wollastonite appeared to have a better CO 2 sequestration effect and provided a wide margin of pH change, but CaCl 2 released Ca2+ directly and decreased the pH of the MEC-AD system. The results showed methane yield reached 137.31 and 163.50 mL/g SCOD degraded and CO 2 content of biogas is only 12.40 % and 2.22 % under 0.8 V with CaCl 2 and wollastonite addition, respectively. Finally, the contribution of chemical CO 2 sequestration by mineral carbonation and biological CO 2 sequestration by hydrogenotrophic methanogenesis was clarified with CaCl 2 addition. The chemical and biological CO 2 sequestration percentages were 46.79 % and 53.21 % under 0.8 V, respectively. With the increased applied voltage, the contribution of chemical CO 2 sequestration rose accordingly. The findings in this study are of great significance for further comprehending the mechanism of calcium addition on CO 2 sequestration in the MEC-AD system and providing guidance for the later engineering application. [ABSTRACT FROM AUTHOR]

Nanotechnology has emerged as a promising approach for the controlled release of nutrients, particularly phosphorus and potassium. These essential plant nutrients are often applied in excess, leading to environmental pollution and loss of efficiency in crop production. Innovative economic and highly efficient fertilizers are urgently needed to achieve the targeted crop production worldwide in the presence of limited land and water resources. Therefore, in this study, novel, eco-friendly, cost-effective and enhanced efficiency nano-enabled fertilizers, NEF (nWTF1and nWTF2) were synthesized by impregnation of nanostructured water treatment residuals (nWTR) with (KH2PO4 + MgO) at 1:1 and 3:1 (w/w) ratios respectively using a planetary ball mill. The nWTR, nWTF1 and nWTF2 were extensively characterized. The water retention behavior and the sustained release of nutrients from the fabricated nano-enabled fertilizers (nWTF1 and nWTF2) in distilled water and sandy soil were investigated and monitored over time. The water retention capacity of the soil treated with nWTF2 after 26 days was 9.3 times higher than that of soil treated with conventional fertilizer. In addition, the nWTF2 exhibited lower release rates of P, K and Mg nutrients for longer release periods in comparison with the conventional fertilizers. This is a significant advantage over traditional fertilizers, which release nutrients quickly and can lead to leaching and nutrient loss. The main interaction mechanisms of PO4–K–Mg ions with nWTR surface were suggested. The results of the kinetics study revealed that power function was the best suitable model to describe the kinetics of P, K and Mg release data from NEF in water and soil. The produced NEF were applied to Zea maize plants and compared to commercial chemical fertilizer control plants. The obtained results revealed that the nano-enabled fertilizers (nWTF1 and nWTF2) significantly promoted growth, and P content compared with the commercial chemical fertilizer treated plants. The present work demonstrated the power of nano enabled fertilizers as efficient and sustained release nano-fertilizers for sustainable agriculture and pollution free environment. [ABSTRACT FROM AUTHOR]

In order to promote the yield and calorific value of combustible gas products in the pyrolysis, a CaO-based biochar (CSC) derived from waste crab shell was used as a low-cost sorption-enhanced catalyst to enhance oil-fried sludge (OS) pyrolysis. The effects of CSC addition and pyrolysis temperature on OS pyrolysis characteristics were analyzed in detail. The results indicated that adding CSC significantly enhanced OS pyrolysis and produced more combustible gas products with CO2 removal. At 700 °C, adding CSC promoted the combustible gas yields and greatly reduced CO2 by 96.9 %. And the corresponding LHV of pyrolysis gas products increased by 26.8 % and reached up to 33.7 MJ/N m3. Additionally, TG-FTIR analysis revealed that adding CSC reduced the formation temperature of CH4. Importantly, although there was only 35.5 wt% of Ca in CSC, CSC exhibited almost the same sorption-catalysis-enhanced effects compared to pure CaO. These findings suggest that biochar derived from crab shell has the potential to replace CaO for enhancing sludge pyrolysis into value-added fuel products. [ABSTRACT FROM AUTHOR]

This research presented, for the first time, the results of the successful application of the waste press sludges, WSLP (plant for lacquer and paint) and WSEP (powdery enamel plant), from a wastewater treatment plant generated during heating device production in the construction industry. The results of WSEP characterization and its influence on cement paste, mortar, and concrete properties showed that this material could be used as a cement replacement (with a maximum replacement amount of 20%) in producing mortar and concrete. Although waste WSLP sludge does not possess pozzolanic properties and does not meet the criteria prescribed by the standards for application in mortar and concrete due to its chemical inertness and fineness, as well as its extended setting time, it can be used as a replacement for stone filler or other powdered mineral admixture in the production of self-compacting concrete (SCC) in amounts up to 100%, with a maximum quantity of up to 100 kg/m3. The obtained results indicate that with the appropriate conversion, waste sludges, despite representing hazardous waste, can be used as safe products in the construction industry; i.e., the waste material can become a useful and valuable raw material by applying (respecting) all of the principles of the green economy. [ABSTRACT FROM AUTHOR]

Due to the high cost and limited sources of cerium coagulants, it is extremely important to take measures to recycle this raw material. This paper presents the new possibility of recovering cerium(III) chloride, cerium(III) sulphate, cerium(IV) sulphate, and potentially phosphate from sewage sludge (101.5 g/kg Ce and 22.2 g/kg total P) through a brewery wastewater treatment process using recycled CeCl3 as a coagulant. In order to recover the Ce and P, the sludge was subjected to extraction using an HCl solution. Optimal process conditions were determined by means of central composite design and response surface methodology (CCD/RSM) for three input parameters (HCl mass, reaction time, and extractant volume). Under optimal conditions (0.35 g HCl per 1 g of sludge, 40 min reaction time, extractant volume of 25 mL per 1 g of sludge), the highest efficiency obtained was 99.6% and 97.5% for Ce and P, respectively. Cerium(III) oxalate as Ce2(C2O4)3∙10H2O was precipitated from the obtained solution using H2C2O4 (99.97%) and decomposed into CeO2 (at 350 °C), which was afterwards subjected to a reaction with HCl (30%, m/m) and H2O2 (30%, m/m), which led to the crystallisation of CeCl3∙7H2O with a purity of 98.6% and a yield of 97.0%. The obtained CeO2 was also subjected to a reaction with H2SO4 (96%, m/m) and H2O2 (30%, m/m), which produced Ce2(SO4)3 with a yield of 97.4%. The CeO2 was also subjected to a reaction with only H2SO4 (96%, m/m), which produced Ce(SO4)2 with a yield of 98.3%. The filtrate obtained after filtering the Ce2(C2O4)3∙10H2O contained 570 mg/L of P, which enabled its use as a source of phosphorus compounds. The presented processes of Ce and potentially P recovery from sewage sludge originating from brewery wastewater contribute to the idea of a circular economy. [ABSTRACT FROM AUTHOR]

Inspired by simulation analysis, we found that Cu decoration could enhance the NH3 production rate of InVO4 through promoting N2 adsorption and reducing the activation energy of the key hydrogenation step. 5% Cu/InVO4 exhibited an optimal NH3 yield of 195.11 μmol gcat−1 h−1, approximately six times higher than that of InVO4. Cu/InVO4 was also fabricated by upcycling Cu from electroplating sludge, achieving a gratifying nitrogen fixation performance of 154.13 μmol gcat−1 h−1. [ABSTRACT FROM AUTHOR]

The rapid degradation of short-chain fatty acids (SCFAs) is an essential issue of anaerobic digestion (AD), in which SCFA oxidizers could generally metabolize in syntrophy with methanogens. The dynamic responses of active metagenome-assembled genomes to low concentrations of propionate and acetate were analyzed to identify specific syntrophic SCFA oxidizers and their metabolic characteristics in continuous-flow AD systems treating waste activated sludge with and without hydrochar. In this study, hydrochar increased methane production by 19%, possibly due to hydrochar enhancing acidification and methanogenesis processes. A putative syntrophic propionate oxidizer and two acetate oxidizers contributed substantially to the syntrophic degradation of SCFAs, and hydrochar positively regulated their functional gene expressions. A significant relationship was established between the replication rate of SCFA oxidizers and their stimulation-related transcriptional activity. Acetate was degraded in the hydrochar group, which might be mainly through the syntrophic acetate oxidizer from the genus Desulfallas and methanogens from the genus Methanosarcina. [ABSTRACT FROM AUTHOR]

[Display omitted] • Sludge dewatering extent was enhanced after Fe 3 O 4 -activated H 2 O 2 treatment. • Enhanced mechanism of sludge dewatering by Fe 3 O 4 -activated H 2 O 2 was unveiled. • Fe 3 O 4 -activated H 2 O 2 disrupted sludge EPS and released intracellular water. • Fe 3 O 4 as skeleton builder enhanced sludge floc strength and formed new channels. Homogeneous Fenton (Fe2+/H 2 O 2) serves as a high-efficiency conditioning method for sludge dewatering due to the generation of strong oxidizing hydroxyl radicals (OH). However, high dose of ferric salts produces iron-rich dewatered sludge and decrease sludge organic matters, which will not be conducive to the subsequent disposal and reutilization. Considering advantages of Fe 3 O 4 as heterogeneous Fenton catalyst, Fe 3 O 4 -activated H 2 O 2 (Fe 3 O 4 + H 2 O 2) in this study was adopted to improve sludge deep-dewatering. Reduction efficiency of the bound water (71.3 %) after Fe 3 O 4 + H 2 O 2 treatment (after a reaction time of 30 min) were much higher than those in the Fe2++H 2 O 2 treatment. Especially, the moisture content of treated sludge cake by Fe 3 O 4 + H 2 O 2 remarkably decreased from 86.4 % to 61.3 %. Improvement mechanism of sludge dewatering after Fe 3 O 4 + H 2 O 2 treatment mainly included electrostatic neutralization, reactive radical oxidation, and skeleton building by analysis of contribution factors. The generation of H+ in acidification could neutralize the negatively charged compounds to promote sludge hydrophobicity. Meanwhile reactive radicals generated from Fe 3 O 4 + H 2 O 2 destroyed sludge extracellular polymeric substances and cell structure to release intracellular water. Furthermore, Fe 3 O 4 as a skeleton builder could reconstruct destructive sludge flocs and form new dewatering channels. Finally, low Fe leaching content and recoverability of Fe 3 O 4 effectively will decrease environmental implication. [ABSTRACT FROM AUTHOR]

[Display omitted] • Gum arabic was utilized as a green stabilizer to prepare water-soluble sulfur dots. • Corrosion inhibition reached the maximum value of 96.5% at 250 mg/L. • Antibacterial efficiency against Bacillus subtilis was up to 99.35% at 250 mg/L. • Fluorescent tracking of water treatment agents was realized. • Facilitated the development of a next generation of multifunction inhibitors agent. In this study, sulfur dots (GA-SDs) synthesized by using Gum Arabic (GA) as a green stabilizer were used as corrosion inhibitors and their inhibition effect for Q235 steel in 3.5- wt% NaCl solution was investigated by weight loss, electrochemical tests, and surface and interface analysis. The results revealed that the inhibition efficiency reached the maximum value of 96.5% at 250 mg/L and the water-soluble GA-SDs were able to adhere to the iron surface through the diffusion and agglomeration effect. The unique antibacterial activities demonstrated a 99.35% inhibition efficiency at 250 mg/L. Moreover, the optical properties endowed the inhibitors with the fluorescence tracing function, which is an effective approach to detecting the residual quantity of water treatment agents. This work may facilitate the development of the next generation of multifunction water treatment agents in industrial circulating water systems. [ABSTRACT FROM AUTHOR]

In recent years, the utilization of the peracetic acid (PAA)-based advanced oxidation process (AOP) for water treatment has gained significant attention. This is due to its ability to generate highly reactive species such as hydroxyl radicals (˙OH) and organic oxygen radicals (R-O˙), which efficiently degrade organic pollutants in water. However, traditional activation methods involving ultraviolet radiation, heat, and transition metal ions have limitations in terms of efficiency, control, and potential metal sludge production. To address these challenges, a novel heterogeneous PAA-based AOP process utilizing the HOF-Cu-g-C3N4 catalyst was developed for high-performance antibiotic removal. This approach effectively coordinates the reaction interfaces, activation sites, and light energy harvesting for enhanced activity and sustainability. X-ray photoelectron spectroscopy (XPS) analysis of HOF-Cu-g-C3N4 indicated that heterogeneous catalysis occurred at two different active sites on the catalyst's surface. The analysis also revealed that the presence of hydroxyl radicals (˙OH) and organic radicals (such as CH3C(O)O˙ and CH3C(O)OO˙) played a significant role in the generation of free radicals in the PAA system. These free radicals were found to dominate the oxidative degradation of antibiotics. The degradation of antibiotics was observed to be effective over a wide pH range, especially at near-neutral pH. Interestingly, the addition of Cl− ions was found to have a notable promotion effect on the degradation of antibiotics. The electrochemical characterization results and free radical measurement provided evidence for the most plausible free radical mechanism and the Cl− ion boosting mechanism. These findings highlight the environmental applicability and versatility of the HOF-Cu-g-C3N4 catalyst for the advanced treatment of refractory pollutants. [ABSTRACT FROM AUTHOR]

Sludge accounts for the highest percentage of waste emissions and needs to be treated efficiently for environmental issues, such as water problems, sanitation and CO2 emission. Although various processes for sludge treatment, such as dewatering, fermentation, drying, carbonization, composting etc., have been developed, effective sludge drying technique was investigated in this study, which can apply not only to organic, but also to inorganic sludge. Besides, the efficient sludge drying process has a potential to exceed the energy conversion efficiency of methane fermentation process by improving the drying efficiency. However, drying technique implemented in this study does not improve the efficiency of sludge drying equipment as in the traditional way, but accelerates sludge drying rate by changing the sludge properties itself to those suitable for drying by adding drying accelerator. In this experiment, resin emulsions were used as a drying accelerator, and sludge drying experiments were conducted using 30 different resin emulsions. The drying acceleration mechanism of resin addition sludge was also inferred by evaluating the change of the resin-addition sludge property. The results revealed that the physical properties of the resin have little influence on the drying acceleration, but the development of hydrophobicity associated with resin curing may have a significant effect on sludge drying acceleration. [ABSTRACT FROM AUTHOR]

Sludge biochar, a carbonized product of raw sludge, contains porous architectures that can act as epicenters for adsorbing external molecules through physical or chemical bonding. Sludge biochar also immobilizes innate micropollutants, which is advantageous over conventional sludge disposal methods. To date, numerous strategies have been discovered to improve sludge biochar morphology, but the influential factors, pore tuning mechanisms, and process feasibility remain imprecise. This knowledge gap limits our ability to design a robust sludge-based biochar. Herein, we present state-of-the-art sludge biochar synthesis methods with insight into structural and chemical transformation mechanisms. Roadblocks and novel concepts for improving sludge biochar porous architecture are highlighted. For the first time, sludge biochar properties, adsorption performances, and techno-economic perspectives were compared with commercial activated carbon (AC) to reveal the precise challenges in sludge biochar application. More importantly, sludge biochar role in carbon sequestration is detailed to demonstrate the environmental significance of this technology. Eventually, the review concludes with an overview of prospects and an outlook for developing sludge biochar-based research. Highlights: Utilizing sludge's unique feature can unlock many new and feasible biochar modulation strategies. Sludge carbonization and activation mechanisms reveal the crucial factors for micropore decorating. Sludge biochar is compared with activated carbon to reveal requirements for practicality. Sludge-based biochar application supports carbon sequestration and economic sustainability. [ABSTRACT FROM AUTHOR]

Novel nanocomposite sorbent was produced by depositing nanostructured water treatment residual (nWTR) onto zeolite (Ze) using high-energy ball milling process. The physicochemical properties of nanocomposite (Ze-nWTR) prior and after Cd adsorption were analyzed by SEM–EDX, FTIR, BET and XRD. A batch study of cadmium adsorption (Ze-nWTR) was performed at various process parameters (sorbent dose, contact time, solution pH, competing ions, initial concentration and temperature). The obtained data were fitted to various equilibrium and kinetics models. The Langmuir and power function models successfully described Cd adsorption equilibrium and kinetic processes, respectively. The maximum adsorption capacity (qmax) value of Cd by Ze-nWTR nanocomposite (147 mgg−1) was 3 and 5.9 times higher than those of nWTR and zeolite sorbents, respectively. Increasing temperature from 287 to 307 K has resulted in increasing the maximum Cd adsorption capacity (qmax) of the nanocomposite from 147.9 to 270 mgg−1. The calculated thermodynamics parameters suggested physical and chemical attraction between Cd and Ze-nWTR and the association of dissociative mechanism in Cd(II) sorption process. The excellent reusability and Cd removal ability of Ze-nWTR nanocomposite (98%) from industrial wastewater confirm its potential as promising adsorbent for wastewater treatment applications. [ABSTRACT FROM AUTHOR]

Considerable attention is paid to improving the environmental safety of additive manufacturing. Manufacturing of articles from titanium using additive technologies (powder metallurgy) is characterized by a high water consumption, and, thus, a large amount of wastewater generated. The paper presents the main trends of using titanium compounds as coagulants for the treatment of natural water (treatment to industrial water grade) and wastewater from additive manufacturing of articles from titanium. It was ascertained that in the processes of wastewater and recycled water treatment, titanium-containing coagulants are much better that the traditional coagulants based on aluminium and iron salts. Treatment of water from surface sources to industrial water grade using titanium coagulants is also highly efficient, and the residual concentrations of pollutants are on average 2.0 - 3.0 times lower than when using the traditional reagents. The use of titanium salts as coagulants allows an average 2-fold reduction of reagent consumption. Coagulation sludge (sediment) forming in the course of water treatment is titanium dioxide and can be used in future as a raw material in different industries. [ABSTRACT FROM AUTHOR]

As the demand for sustainable construction practices increases, alternative materials are being explored to reduce waste and carbon emissions. This study investigates the feasibility of utilizing recycled geopolymer binder as a substitute for ordinary sand in the production of geopolymer mortar. The study examines the effects of various replacement rates of recycled geopolymer on the physical, mechanical, and thermal properties of the geopolymer mortar. The results indicate that geopolymer mortar incorporating recycled geopolymer binder as a replacement for ordinary sand exhibits similar mechanical properties to traditional geopolymer mortar, with minor decreases in compressive and flexural strength as the replacement rate increased. The geopolymer mortar also demonstrated lower thermal conductivity than traditional mixes, resulting in increased thermal insulation. These findings suggest that using recycled geopolymer binder as a replacement for ordinary sand in geopolymer mortar production could be a promising approach for sustainable construction practices. [ABSTRACT FROM AUTHOR]

In the present study, drinking water treatment sludge (DWTS) was reused as a catalyst in advanced oxidation processes for the removal of methylene blue (MB) from aqueous solutions. After determining their chemical and mineralogical compositions by X-ray Powder Diffraction (XRD), BET surface area, scanning electron microscopy with energy dispersive spectroscopy (SEM/ EDS), Inductively Coupled Plasma (ICP), and FT-IR spectra. DWTS has been used as a heterogeneous photo Fenton-Like catalyst for the oxidation of MB under different parameters, including pH (3-6), H2O2 concentration (9.79-29.37 mM), and dose (1-2.5 g/L). The results showed that within 180 min and under UV light irradiation, more than 86% of MB having a concentration of 50 mg/L were removed using a catalyst loading of 1.5 g/L, a H2O2 dosage of 23.17 mM and a solution pH of 5. The DWTS has a satisfactory stability as the catalyst is stable and have very less iron leaching property. [ABSTRACT FROM AUTHOR]

Jarosite is a specific type of hazardous waste determined by the origin of the primary raw materials of the hydrometallurgical process of zinc production. It represents a very demanding raw material for further treatment and recover of valuable metals due to their complex phase structures. The aim of this study was to collect relevant data for the designing the process of thermal decomposition of jarosite Pb–Ag sludge desired structure, which includes the transformation of Fe(II) and Fe(III) sulfates to insoluble hematite, retention of Cu, Zn and In in the form of soluble sulfates, with the possibility of their subsequent valorization by hydrometallurgical methods. Thermal decomposition of the industrial sample of jarosite Pb–Ag sludge is investigated under different temperatures (670–750 °C) and atmospheres (air and nitrogen) by thermodynamic, thermogravimetric and kinetic analysis. Physicochemical characterization of samples was done by ICP-MS, AAS, IMS, XRD, SEM techniques. The examined sample is ammonium jarosite type with the dominant phases NH4Fe3(SO4)2(OH)6 × H2O (44.00%) and ZnFe2O4 (15.25%). Experimental results, physicochemical characterization and thermodynamic analysis confirmed that the maximum content of hematite (Fe2O3) and metal sulfates (Cu, Pb and Zn), as required compounds for selective metal extraction, without the presence of unreacted ammonium jarosite, was obtained at 730 °C. A kinetic study obtained by thermogravimetric analysis showed that the thermal decomposition of jarosite Pb–Ag sludge takes place in two phases. The activation energy, calculated using the Kissinger–Akahira–Sunose iso-conversion method, was 235.4 kJ mol−1 and 208.8 kJ mol−1 for the decomposition of jarosite in air and nitrogen, respectively. [ABSTRACT FROM AUTHOR]

Bioreactor landfilling even being advanced technology for enhanced stabilization of municipal solid waste (MSW), often suffers with adverse acidogenic conditions. Such conditions reinforce poor leachate stabilization, and reduced biomethane yield. This work attempts to counter the challenges of adverse MSW landfilling conditions through incorporation of waste alkaline sludge from paper industry. The amendment in anaerobic bioreactor landfilling of MSW was practiced by adding lime sludge (LS) with MSW in three distinct proportions: 20 g LS/kg MSW (LS100), 50 g LS/kg MSW (LS250) and 100 g LS/kg MSW (LS500), keeping LS0 as control. Periodic leachate and biomethane analysis showed benefits of proportionate LS addition. The control reactor often experienced leachate ponding and inhibitory conditions for anaerobic digestion. However, reactor LS250 achieved highest decrease in leachate organic strength removal (76.47 %) and biomethane production (8.315 L) over the period of landfilling. The pH and volatile fatty acids (VFAs) were in coordination with LS proportions. The LS addition beyond 100 g LS/kg MSW (LS500) could decrease the leachate pollution removal and biomethane yield. Finally, the Gompertz growth model showed excellent fit (R2 >0.997) to recorded biomethane. The study expands the scope of utilizing similar sludges for amendment of existing landfilling practices for efficient bioconversion of organic fractions of MSW. [Display omitted] [ABSTRACT FROM AUTHOR]

Steel is a crucial industrial product with applications in various sectors, such as construction, engineering, and industry. However, the steel industry generates significant waste, contributing to greenhouse gas emissions and environmental challenges. To address this issue, incorporating solid waste, especially sludge with high moisture content, into the steel industry's operations is essential. This study aimed to construct and test an active indirect solar dryer for reducing the moisture content of sludge from a steel drawing industry. By employing principles of the circular economy and the environmental, social, and governance concept, the drying process showed promising results, achieving approximately 42% moisture reduction. This study involved collection and characterization of industrial sludge, design and assembly of a hybrid active indirect solar dryer, fluid dynamic analysis of the behavior of the air inside the device through CFD Ansys software 2012, tests with a thermographic camera to validate the simulation, and optimization of the sludge drying by calculating the thermal efficiency and drying efficiency of the equipment. The adoption of such drying processes can lead to substantial cost reductions in the transportation, handling, and landfilling of steel-drawing sludge, promoting innovation and aiding global steel industries in achieving their solid waste disposal targets. [ABSTRACT FROM AUTHOR]

The article is devoted to the experimental determination of thermokinetic parameters of oil sludge thermal degradation using the model-free Ozawa-Flynn-Wall method in the presence of a nanocatalyst (nickel, cobalt and iron-supported microsilicate) by calculating Arrhenius kinetic parameters (activation energy and pre-exponential factor). The phase composition of the reflex microsilicate was established – 4.12; 2.51 Å – SiO2, nickel-supported microsilicate reflexes: 2.09; 1.48 Å – NiO, reflexes: 4.25 Å – SiO2 and acid numbers of microsilicate – 64 μmol/g of prepared nanocatalysts. Using the method of Brunauer, Emmett and Teller, the specific surface area of the microsilicate was established – 18.3 ± 0.3 m2/g, the microsilicate with nickel applied – 20.9 ± 0.2 m2/g and the adsorption isotherm of the prepared nanocatalysts (microsilicate with nickel, cobalt and iron). Thermokinetic parameters of thermal decomposition of oil sludge without a catalyst and with a catalyst at an increment of 0.9 are 99.0 and 93.3 kJ/mol nickel-supported microsilicate, 51.9 kJ/mol cobalt-supported microsilicate, 111.3 kJ/mol iron-supported microsilicate and non-metal-supported microsilicate 173.7 kJ/mol, respectively. The study of the kinetic parameters of pyrolysis of oil sludge using various catalysts makes it possible to assess their influence on the process of decomposition of organic components. The results of the experiments showed that the use of catalysts significantly affects the destruction of oil sludge. Dynamic thermal analysis at different heating rates studied the dynamics of oil sludge decomposition. The study of the effect of catalysts on the kinetic parameters of oil sludge pyrolysis is an important step in the development of new methods for the disposal of petroleum products and the reduction of their negative impact on the environment. The obtained experimental data on thermal degradation kinetics of oil sludge will find application in designing a reactor for the process of destructive hydrogenation of heavy hydrocarbon raw materials. [ABSTRACT FROM AUTHOR]

Water treatment sludge (WTS) is produced daily and disposed of as hazardous material. It would be advisable to use locally available waste products as supplementary cementitious materials that ensure to be disposed of without harming the environment. As a novelty, this research investigated the potential of using recycled WTS with fly ash (FA) and ground-granulated blast furnace slag (BFS) as ternary blended binders. Thus, it can provide an economical solution and alleviate the adverse environmental effects of excessive production of wastes and cement production. Within this scope, the mortars with 0–30 wt% replacement of cement with modified WTS (MWTS) were produced as binary blend, and also, they were combined with FA/BFS as ternary blended binders. Therefore, optimum utilization of waste products into the mortar in terms of rheological, mechanical, durability, microstructural properties, and environmental-economical aspects was examined. Adding 10% recycled WTS as binary caused higher strengths with lower porosity measured by the mercury intrusion porosimeter test and denser microstructure, as revealed by XRD patterns and SEM results. However, the drawbacks of using recycled WTS, in terms of rheological parameters and environmental-economical aspects, were suppressed by adding FA/BFS with comparable strength values. Specifically, cost, CO2 footprint, and embodied energy were reduced by combining 10% MWTS with FA by 8.87%, 37.88%, and 33.07%, respectively, while 90-day compressive and flexural strength were 5.1% and 5.32% lower. This study developed a feasible solution to use recycled MWTS by obtaining more eco-friendly and cost-effective cement-based materials. [ABSTRACT FROM AUTHOR]

An aluminum sludge-based composite material was constructed against the problems of phosphorus pollution and the waste of aluminum sludge resources. Utilizing metal Ce doping and hydrogel microbeads with pore preparation, the adsorption performance of the original sludge was improved. Meanwhile, the macroscopic body was constructed, and on this basis, polyethyleneimine (PEI) was introduced to complete the amino functionalization further to enhance the adsorption of phosphorus by the adsorbent, and NH-CeAIS-10 microbeads were successfully prepared. In adsorption, microbeads with larger specific surface area and richer functional groups are better choice compared to original sludge. The results of SEM, BET, FT-IR, and XPS analyses indicate that the adsorption of phosphorus by the microbeads is mainly achieved through electrostatic interactions, ligand exchange, and the formation of inner-sphere complexes. According to the Langmuir model, the maximum phosphorus adsorption capacity of NH-CeAIS-10 was 29.56 mg g−1, which was four times higher compared to native aluminum sludge. This also confirms the significant enhancement of phosphorus adsorption through the modification of aluminum sludge. Besides, in dynamic adsorption column experiments, the material exhibited up to 99% removal in simulated wastewater for up to 30 days, demonstrating the great adsorption potential of NH-CeAIS-10 in engineering applications. [ABSTRACT FROM AUTHOR]

Modified sludge biochar, recognized for its notable economic and environmental benefits, demonstrates potential as an effective catalyst for peroxydisulfate (PDS) activation. Nevertheless, the specific mechanisms underlying its catalytic performance require more comprehensive investigation. In this study, a modified biochar (TSBC) doped with oxygen (O) and nitrogen (N) atoms was synthesized from sewage sludge and tannin extract, which significantly enhanced the activation of PDS for the degradation of sulfamethoxazole (SMX). The TSBC/PDS system demonstrated robust performance for SMX degradation, achieving over 90% efficiency over a wide pH range (3–10). Subsequent quenching experiments demonstrated that TSBC predominantly catalyzed PDS to generate O 2 1 , which effectively degraded SMX via a non-radical pathway. The O- and N-containing functional groups in TSBC were identified as the primary catalytic sites. Besides, density functional theory (DFT) calculations revealed that the incorporation of graphitic N significantly improved the adsorption capacity of PDS on the TSBC surface. Furthermore, based on the identification of intermediates and theoretical calculations, SMX was degraded mainly by two different pathways: S-N cleavage and O 2 1 oxidation. This study offers a foundational framework for the targeted modification of sludge biochar, thereby expanding its applications. [ABSTRACT FROM AUTHOR]

Various factors, such as rainfall conditions, may influence nutrient removal by bioretention filters. The aim of this study was to evaluate how antecedent dry periods (ADP) affected the removal of nutrients by a laboratory-scale bioretention system. A bioretention filter system comprising columns with different media, treatment, and submerged zone combinations was set up. The treatments included 10% (v/v) water treatment residual to enhance the phosphorus (P) removal and 10% (v/v) zero-valent iron to enhance the nitrogen (N) removal. Semi-synthetic runoff was applied to explore how ADPs (from 1 to 10 days) affected the N and P removal. The denitrification efficiency was determined from the variations in the N concentrations in the submerged zone over 14 days. Without a submerged zone, the total nitrogen (TN) removal increased, the chemical oxygen demand (COD) removal decreased, and there was no clear trend for total phosphorus (TP), dissolved P, or particulate P as the duration of the ADP increased. When the bioretention filter had a submerged zone, the TN removal peaked at 82.64 ± 0.24% and 84.50 ± 0.28% for an ADP of 10 days. When zero-valent iron was added to a filter with a submerged zone, the denitrification improved significantly, and the TN removal reached 92.95 ± 1.50% and 92.16 ± 2.28% for an ADP of 5 days. The iron also significantly promoted the COD and TP removal efficiencies of the bioretention filter, but was not significantly related to the ADP. The TN and ammonia concentrations in a filter with a submerged zone decreased significantly in the first 3 days of the ADP, and then stabilized after 5 days. These results provide a reference for determining the effectiveness of a submerged zone in bioretention systems. [ABSTRACT FROM AUTHOR]

In recent years, the utilization of the peracetic acid (PAA)-based advanced oxidation process (AOP) for water treatment has gained significant attention. This is due to its ability to generate highly reactive species such as hydroxyl radicals (˙OH) and organic oxygen radicals (R-O˙), which efficiently degrade organic pollutants in water. However, traditional activation methods involving ultraviolet radiation, heat, and transition metal ions have limitations in terms of efficiency, control, and potential metal sludge production. To address these challenges, a novel heterogeneous PAA-based AOP process utilizing the HOF-Cu-g-C3N4 catalyst was developed for high-performance antibiotic removal. This approach effectively coordinates the reaction interfaces, activation sites, and light energy harvesting for enhanced activity and sustainability. X-ray photoelectron spectroscopy (XPS) analysis of HOF-Cu-g-C3N4 indicated that heterogeneous catalysis occurred at two different active sites on the catalyst's surface. The analysis also revealed that the presence of hydroxyl radicals (˙OH) and organic radicals (such as CH3C(O)O˙ and CH3C(O)OO˙) played a significant role in the generation of free radicals in the PAA system. These free radicals were found to dominate the oxidative degradation of antibiotics. The degradation of antibiotics was observed to be effective over a wide pH range, especially at near-neutral pH. Interestingly, the addition of Cl− ions was found to have a notable promotion effect on the degradation of antibiotics. The electrochemical characterization results and free radical measurement provided evidence for the most plausible free radical mechanism and the Cl− ion boosting mechanism. These findings highlight the environmental applicability and versatility of the HOF-Cu-g-C3N4 catalyst for the advanced treatment of refractory pollutants. [ABSTRACT FROM AUTHOR]

The subject of the research was the recovery of raw materials from waste generated in the production of cable insulation and the management of aluminum sludge. It was found that 49% (w/w) acetophenone, 6.8% (w/w) α-methylstyrene, and 17.2% (w/w) cumyl alcohol can be recovered from waste with a loss on ignition of 95% and used in various industries. A gas chromatograph equipped with a mass spectrometry detector was used to identify the recovered compounds. A waste distillation process was proposed to remove the water layer and obtain a concentrated acetophenone fraction. A method of neutralizing the water fraction and distillation residues is presented. The proposed waste management method is an alternative method to the currently used thermal transformation method. In turn, aluminum sludge was used to produce aluminum sulfate, which was used in the plant's sewage treatment plant as a coagulant. The effect of this action was a reduction of 67% in the content of total iron, 60% of trivalent iron, and 32% of chemical oxygen demand. The above-mentioned examples of waste management are part of a closed-loop waste management strategy. [ABSTRACT FROM AUTHOR]

Recent studies have reported that Fenton sludge and biochemical sludge contain high concentrations of toxic substances and heavy metals (HMs), whereas improper treatment can pose serious threats to environmental safety. Pyrolysis is considered an efficient technology to replace conventional sludge treatment. This study investigated the pyrolysis and kinetic processes of Fenton sludge and biochemical sludge, revealed the physicochemical properties of sludge biochar, and highlighted the role of co-pyrolysis in sludge immobilization of HMs and environmental risks. Results showed that Fenton sludge and biochemical sludge underwent three stages of weight loss during individual pyrolysis and co-pyrolysis, especially co-pyrolysis, which increased the rate of sludge pyrolysis and reduced the decomposition temperature. The kinetic reaction indicated that the activation energies of Fenton sludge, biochemical sludge, and mixed sludge were 11.59 kJ/mol, 8.50 kJ/mol, and 7.11 kJ/mol, respectively. Notably, co-pyrolysis reduced the activation energy of reactions and changed the specific surface area and functional group properties of the biochar produced from sludge. Meanwhile, co-pyrolysis effectively immobilized Cu, Pb, and Zn, increased the proportion of metals in oxidizable and residual states, and mitigated the environmental risks of HMs in sludge. This study provided new insights into the co-pyrolysis properties of sludge biochar and the risk assessment of HMs. [ABSTRACT FROM AUTHOR]

Copyright of Materials & Technologies / Materiali in Tehnologije is the property of Institute of Metals & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The management of cereal grain processing industry sludge through vermicomposting is an emerging prospect for researchers interested in the green economy. This work is designed to enumerate the enzymatic influence of three epigeic earthworm species — Eisenia fetida, Eudrilus eugeniae, and Perionyx excavatus on the industrial sludge. The vermicomposting experiment was conducted in plastic pots by blending the waste materials with 5% cow dung. The dynamics in activities of cellulase, amylase, invertase, phosphatase, protease, dehydrogenase, and urease were studied on 15 days intervals till the harvesting period. The periodical observations confirmed that the enzyme activities (in terms of μg reducing sugar/g/hr) of cellulase (26.45–128.09) amylase (205.43–878.96), invertase (105.32–841.65), phosphatase (85.29–435.54), protease (64.21–359.47), dehydrogenase (111.17–587.72), and urease (94.16–476.71) was low in the first 15 days of the vermicomposting experiment followed by a sharp increase in the next 45 days accompanied by a steady decline until the harvesting is carried out. Emerging statistical tools such as principal component analysis were employed to study the synergistic deviations of the enzymes during the vermicomposting process. The results confirmed that the enzyme activity efficiently influences the bio-oxidation of industrial waste at an individual level as well as synergistic level thereby allowing the vermicompost to mature much before the appearance of any physical symptoms on the surface of the vermireactors. [ABSTRACT FROM AUTHOR]

Fly ash-based geopolymers have emerged as a sustainable alternative in construction, leveraging industrial by-products to mitigate CO2 emissions. This study investigates the novel incorporation of drinking water treatment sludge (DWTS) into fly ash-based geopolymers at varying proportions (5–40%). Authors focus is to analyze the thermophysical properties and environmental implications, including a robust life cycle assessment case study conducted within the Moroccan context. The comprehensive analysis encompassed X-ray powder diffraction, apparent porosity, water absorption, scanning electron microscopy, hot disc, compressive strength, and a comparative assessment of fly ash-based geopolymer containing 20% of DWTS (GP-DWTS-20) and ordinary Portland cement (OPC). Notably, the results reveal that DWTS enhances thermal performance, with a remarkable 33% reduction in thermal conductivity observed in geopolymers containing 20% DWTS. This enhancement motivates the potential for innovative fly ash-based geopolymers. Moreover, the study contributes quantifiable evidence of a substantial 48% reduction in global warming potential for DWTS-based geopolymers compared to OPC. These findings underscore the environmental benefits of this alternative while emphasizing avenues for optimization in alkaline solution, curing, and renewable energy integration. [ABSTRACT FROM AUTHOR]

This study investigated the effect of cation polyacrylamide (CPAM) on the dewatering performance of dredged sludge by batch experiments and compared it with a novel organic agent (DRC-300) and a traditional inorganic agent (PAC). The results of batch experiments suggested that the CPAM could promote the dewatering performance of dredged sludge inland lake. And at the dosage of 0.07% g/g suspended solids (SS), the moisture content of 37% could be achieved with CAPM. CPAM could reduce the sludge resistance filtration (SRF) and capillary adsorption time (CST) by 73% and 62%, respectively. Mechanism experiments revealed that CPAM improved the dewatering performance of dredged mud by increasing the sedimentation rate, accelerating the dissolution of organic matter, neutralizing the surface charge of sludge, and improving the void structure. Furthermore, CPAM outperformed DRC-300 and PAC in above aspects. [ABSTRACT FROM AUTHOR]

The building blocks of biofilm are called extracellular polymeric substances (EPSs), and they are composed of biopolymers. The optimal properties of EPSs include chemical interactions, resistance to dehydration, and resilience in the face of hazardous shock loads. It is necessary to have an understanding of EPSs extraction, composition, and the biomatrix's reaction to contaminants. This research aims to conduct chemical extraction to determine the amounts of EPSs found in unspiked-metaldehyde and spiked-metaldehyde rubber aerobic granular sludge (rAGS) and newly invented molasses aerobic granular sludge (mAGS). The rAGS was produced by feeding synthetic wastewater into sequencing batch reactors (SBRs). The mAGS was developed by adding the rAGS with different volumes of molasses wastewater. The EPSs were successfully extracted and identified by quantifying the number of proteins and carbohydrates present in each rAGS and mAGS condition. Hydroxyl, carboxyl, and amino groups showed that rAGS and mAGS EPSs contained carbohydrates and proteins. The compositions of the EPSs showed a strong correlation with the concentrations of metaldehyde in the spiked-metaldehyde rAGS and mAGS samples. When the total EPSs are taken into consideration, both rAGS and mAGS that are formed are effective treatments for metaldehyde treatment in wastewater. [ABSTRACT FROM AUTHOR]

Copyright of Petroleum Geology & Oilfield Development in Daqing is the property of Editorial Department of Petroleum Geology & Oilfield Development in Daqing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The bottom ash (OIBA) generated from the incineration of hazardous oil sludge is classified as a hazardous waste. In this work, the OIBA was applied as raw material to prepare SiO 2 -Al 2 O 3 -CaO system glass-ceramics by melt-sintering with the addition of waste glass wool (GW). The effects of basicity (CaO/SiO 2 ratio, 0.52-1.05) and sintering temperature (900–1050 °C) on the crystallization kinetics, properties, microstructure, leaching concentrations of heavy metals and potential toxicity of glass-ceramics were investigated. The results showed that the crystallization pattern was two-dimensional crystallization, and with the decrease of basicity, the main crystalline phase evolved from gehlenite to diopside. And the glass-ceramics with basicity of 0.88 and sintering temperature of 950 °C exhibited the best comprehensive properties, including density (2.72 g/cm3), water absorption (0.06%), compressive strength (452.45 MPa) and chemical corrosion resistance. In addition, the reduction of heavy metal leaching concentration indicates that produced glass-ceramics showed excellent solidification effect on heavy metals, the low toxicity of glass-ceramics leaching solution to the wheat seeds and Artemia suggests the environmental protection characteristics of OIBA-based glass-ceramics. These findings proved that the glass-ceramics produced by OIBA and GW could be a promising method to dispose hazardous waste with preparing high value-added construction materials. [ABSTRACT FROM AUTHOR]

The river sludge in Wujin District, Changzhou City has seriously affected the surrounding environment, and the treatment and disposal of sludge has become a major problem. In this project, the combined technology of cutter suction and plate-frame pressure filtration is used to effectively treat the dredged river sludge. The combined technology specifically includes environment-friendly dredging system, pre-treatment system, conditioning and modification system, dehydration and consolidation system, and tail water treatment system. The results showed that the river sludge was separated into sludge cake and tail water from the solids/liquid mixture, wherein the sludge cake met the requirements of GB/T 23485-2009 Standard for Sludge Disposal and Mixed Landfill in Urban Sewage Treatment Plants, and the tail water met the standard of Class V water specified in GB 3838-2002 Environmental Quality Standard for Surface Water, meeting the design discharge requirements, with good social benefits. [ABSTRACT FROM AUTHOR]

The technological process of natural water treatment before being supplied to the water supply network is accompanied by the formation of water treatment sludge. The chemical composition of water treatment precipitation is characterized by the presence of aluminum and iron hydroxides, manganese oxide, and an undissolved residue of chemical reagents used in water treatment. The strategy of sustainable development presupposes proper management of man-made waste, capable of ensuring their reuse and reducing the associated environmental burden on the environment. There are known options for using water treatment sludge in the production of bricks, expanded clay, and cement. The use of water treatment sediments in the production of burnt ceramic materials is effective. A promising direction for the utilization of water treatment sludge is the possibility of its use in a mixture with peat as a potential raw material for the production of construction and ceramic materials. An installation is developed for the collection of milled peat, its mixing with water treatment sludge, and subsequent drying of the resultant mixture. [ABSTRACT FROM AUTHOR]

Aluminum is present in significant concentrations in water treatment residue (WTR), a waste product obtained during turbidity removal in drinking water treatment. This study aimed at exploring the potential for recovery of coagulant from WTR using Acidithiobacillus ferroxidans (ATF) and reusing the recovered coagulant (RC) for turbidity removal from water. The activity of ATF was measured by monitoring the pH and Al recovery (in %, AlR%). The effects of two factors (WTR and sulfur dose) on the activity of ATF were studied using central composite design (CCD) and response surface methodology (RSM). The results indicated that the bacteria activity decreased with an increase in WTR dose. The results also revealed that the sulfur dose does not have a significant effect on the ultimate AlR%; however, it significantly reduced the time required for achieving AlR%. ANOVA analysis indicated that the obtained model and factors were significant. The maximum AlR% around 70.9% was obtained with 10 g/L of WTR dose and 8 g/L of sulfur dose. The RC was reused for the turbidity removal from lake water and synthetic turbid water (STW) and compared with the turbidity removal achieved with 1% (w/v) aluminum sulfate. The doses of RC to bring the turbidity <5 NTU in lake water and STW were found to be 0.75 and 1 mL/L respectively. To obtain similar turbidity level, the dose required with aluminum sulfate was 2.5 and 1.5 mL/L for lake water and STW, respectively. There was no significant change in the pH and sulfate and metal concentrations in the effluent treated with RC. The results obtained indicate that the RC is efficient in turbidity removal. The RC, therefore, has potential to reduce the demand for fresh alum for water treatment purposes and provide an alternative use of a waste material. [ABSTRACT FROM AUTHOR]

In this study, drinking water treatment sludge was activated and used as an efficient, cheap and cost effective sorbent in the removal of Fe(III) ion from water samples. The prepared material was characterized by Fourier transfer infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), scanning electronic microscopy (SEM), surface analysis (BET method) and X-ray fluorescence (XRF) analysis. The effects of various parameters such as the solution pH, adsorption time, adsorbent dosage, and initial metal ion concentration upon adsorption were investigated. Equilibrium isotherm studies were carried out with different initial concentrations of Fe(III), and two models (Langmuir and Freundlich isotherms) were utilized to analyze the equilibrium adsorption data. The results revealed that the adsorption process obeyed the Langmuir model, with the maximum monolayer capacity (qmax) and the Langmuir constant (KL) calculated as 54.3 mg g-1 and 1.19 L mg-1, respectively. Kinetic studies indicated that the adsorption process followed a pseudo-second-order model. The results showed that activated sludge is an efficient and selective material for adsorption of Fe(III). [ABSTRACT FROM AUTHOR]

Sludge from a purification plant for waste waters are studied for presence of pathogenic and non-pathogenic microflora. Their disinfection is carried out by applying lime treatment (10%, 20%, 30% lime) with two species vegetation – lavender (Lavandula) and basil (Ocimum). The results obtained after the processing of the sludge about the quantity microflora in them are studied for presence of a correlation connection between the concentration of the lime solution and the quantity of microorganisms. The obtained results show a strong correlation connection among the studied quantities. This gives grounds to be looked for a mathematical model on description of the microflora quantity in the sludge. More factors are added for the purpose – temperature, humidity and pH. In the article are presented the regression equations for the different methods of disinfection. The results give grounds to be affirmed that most of them can be used successfully for finding the quantity microflora in studied sludge with known data for concentration of the solution, temperature, humidity and pH. [ABSTRACT FROM AUTHOR]

The dewatering treatment is an essential process for the treatment and disposal of surplus activated sludge (SAS), and improving sludge dewatering performance is still a challenge and has become a research hotspot in recent years. The oxidation and disintegration of bacterial cells and extracellular polymeric substances (EPS) by active radicals produced by advanced oxidation processes (AOPs) were extremely promising to achieve deep sludge dewatering. This paper systematically studied the efficiency and mechanism of thermally activated persulfate (TAP) oxidation technology to the improvement of SAS dewatering performance. The results showed that the relative filterability (CST0/CST) was increased 2.52 times with 2.0 mmol/g VSS potassium peroxydisulfate (PDS) at 80 °C in 90 min. Under this condition, the Zeta potential of SAS significantly decreased from − 14.8 to − 1.44 mV, while the average particle size (dp50) decreased from 52.981 to 48.259 μm. Thermal treatment disrupted the sludge structure to release large amounts of EPS including polysaccharides and protein. Meanwhile, the results of three-dimensional excitation–emission matrix (3D-EEM) fluorescence spectra showed that the TAP treatment could expedite the disintegration of sludge, facilitating the decrease of total EPS content and conversion of tightly bound EPS (TB-EPS) to loosely bound EPS (LB-EPS) and soluble EPS (S-EPS). The mechanism of TAP process to improve SAS dewatering performance was revealed, which could contribute to breaking the bottleneck of sludge depth dewatering and provide a theoretical and technical basis for its practical application. [ABSTRACT FROM AUTHOR]

Environmental protection is becoming a primary objective when choosing processes and technologies for treating oily waters resulting from hydrocarbon production. The focus of treating oily waters is to eliminate contaminants from effluents before discharging them into the receiving environment while adhering to discharge standards. Our work aims to analyze the treatment process for oily waters in the API unit of the North Industrial Center (CINA), which involves a physical–chemical treatment using activated silica and Kurifix. The study aims to improve the treatment process used for oily water treatment to ensure water conservation for reuse. To enhance the CINA-HMD oily water treatment process, we created coagulants with different doses (C1–C6) using sodium silicate, activated silicate (sodium silicate + sulfuric acid), distilled water, Kurifix, and an oxygen scavenger while measuring pH, HC (hydrocarbon), and SS (suspended solids) levels. Coagulation and flocculation processes were used to remove suspended solids and hydrocarbons from the water. The results show that the coagulant used reduces suspended matter and hydrocarbon content and increases pH. The best treatment is achieved with a coagulant prepared with distilled water, 5% sodium silicate, and 2% sulfuric acid. The optimal dose of coagulant is 16 ppm. Automatic dosing provides better efficiency than manual dosing. The study recommends continuous verification of chemical preparation and injection, periodic cleaning of settling tanks, and monitoring of oily water entering the station. [ABSTRACT FROM AUTHOR]