Aluminum Sulfate Research Articles

Solidification and Stabilization of Fluorine and Phosphorus in Phosphate Mine Tailings and the Mechanism of F and P Fixation During Soilization

AbstractResearching methods for harmless and resourceful utilization of phosphate mine tailings presents a new approach to addressing phosphate mine tailings pollution. This study selected a formulation of agents for solidifying fluorine and phosphorus in phosphate mine tailings, investigating the solidification effects of phosphorus and fluorine under different temperatures and time, as well as the changes in the physicochemical properties of phosphate mine tailings. Solidified phosphate mine tailings soilization results showed that phosphate mine tailings: polymerized aluminum sulfate: ferrous sulfate=96.5 : 1.75 : 1.75 worked well, with a leaching toxicity of fluorine of 0.9569 mg/L, a fixation rate of 74.92 %, and a retention of water‐soluble phosphorus of up to 82.75 %. At 25 °C and 28 days of cultivation, the leaching toxicity of phosphate mine tailings treated with the solidifying agent was less. Solidified phosphate mine tailings were again added with solidifying agent to solidify phosphorus and fluorine, and the stabilization rate of fluorine reached 90.08 %. The “soil” cultivated for 28 days had an optimal structure of nutrients, and the germination rate of cabbage seeds was 83.33 %. This study demonstrates the possibility of using phosphate mine tailings as planting soil, and provides a useful theoretical basis for the fluoride fixation mechanism in phosphate mine tailings.

Integrated Transcriptome and Metabolome to Elucidate the Mechanism of Aluminum-Induced Blue-Turning of Hydrangea Sepals

Hydrangea macrophylla is an ornamental plant with varied calyx colors. Interestingly, from red, to purple, to blue, the colors of all Hydrangea macrophylla are formed by unique delphinidin-3-O-glucoside and aluminum ions (Al3+) and 5-O-p-coumaroylquinic acid. The sepals of ‘Blue Mama’ changed from pink to blue, and the contents of delphinidin-3-O-glucoside and aluminum ions increased under 3 g/L aluminum sulfate treatment. However, the mechanism of the effect of aluminum ions on the synthesis and metabolism of anthocyanins in Hydrangea macrophylla is still unclear. In this project, transcriptome sequencing and anthocyanin metabolome analysis were performed on the sepals of ‘Blue Mama’ during flower development at the bud stage (S1), discoloration stage (S2) and full-bloom stage (S3) under aluminum treatment. It was found that delphinidin, delphinidin-3-O-glucoside and delphinidin-3-O-galactoside were the main differential metabolites. The structural genes CHS, F3H, ANS, DFR and BZI in the anthocyanin synthesis pathway were up-regulated with the deepening in sepal color. There was no significant difference between the aluminum treatment and the non-aluminum treatment groups. However, seven transcription factors were up-regulated and expressed to regulate anthocyanin synthesis genes CHS, F3H, BZI and 4CL, promoting the sepals to turn blue. The KEGG enrichment pathway analysis of differentially expressed genes showed that the glutathione metabolism and the ABC transporter pathway were closely related to anthocyanin synthesis and aluminum-ion transport. GST (Hma1.2p1_0158F.1_g069560.gene) may be involved in the vacuolar transport of anthocyanins. The expression of anthocyanin transporter genes ABCC1 (Hma1.2p1_0021F.1_g014400.gene), ABCC2 (Hma1.2p1_0491F.1_g164450.gene) and aluminum transporter gene ALS3 (Hma1.2p1_0111F.1_g053440.gene) were significantly up-regulated in the aluminum treatment group, which may be an important reason for promoting the transport of anthocyanin and aluminum ions to vacuoles and making the sepals blue. These results preliminarily clarified the mechanism of aluminum ion in the synthesis and transport of anthocyanin in Hydrangea macrophylla, laying a foundation for the further study of the formation mechanism of ‘blue complex’ in Hydrangea macrophylla.

Effect of the modification of Pinus Kraft pulp with aluminum sulfate in cementitious composites

Effect of the modification of Pinus Kraft pulp with aluminum sulfate in cementitious composites

Influence mechanism of leaching agent anions on the leaching of aluminium impurities in ionic-type rare earth ores: A DFT simulation combined with experimental verification

The aluminium impurity present during the leaching process of ionic-type rare earth ores increases the complexity and cost of the subsequent dealumination procedure, causing the loss of rare earth elements. Understanding the interactions between minerals and impurities is crucial for grasping interfacial reactions. However, the mechanism by which anions influence the adsorption behaviour of Al3+ remains unclear. This study examined the impact mechanisms of four typical leaching agent anions (SO42-, Cl-, NO3–, and CH3COO–) on the interaction between Al3+ and the kaolinite (001) surface using density functional theory (DFT). According to DFT calculations, the order of adsorption energy of Al3+ on the kaolinite (001) surface in the presence of anions is as follows: Al3+ < Al3+ in aluminium sulfate < Al3+ in aluminium chloride < Al3+ in aluminium nitrate < Al3+ in aluminium acetate. The adsorption strength of Al3+ on the kaolinite (001) surface is weakened to varying degrees by the presence of anions. Specifically, under the influence of acetate anions, it is difficult for Al3+ to adsorb and form bonds on the kaolinite (001) surface. In contrast, Al3+ can still adsorb mainly through Al-O ionic bonds under the influence of the other three anions. The density of states analysis showed that the 3p orbitals of Al atoms and the 2p orbitals of O atoms primarily contribute to the Al-O bond near the Fermi energy level. Experimental results from adsorption capacity tests, microcalorimetry, and zeta potential measurements support the DFT simulations, indicating that Al2(SO4)3 is the most easily adsorbed on the kaolinite surface, followed by AlCl3 and Al(NO3)3, with (CH3COO)3Al being the most difficult to adsorb. Column leaching tests further verified that adding CH3COO– to the leaching agent solution at pH > 4.5 can inhibit the leaching of aluminium impurities, enabling the efficient separation of rare earth elements from aluminium impurities, and reducing the aluminium content in the leachate.

Coagulation tests of waste pulp from copper mineral processing

The sustainable use of water in mineral processing is essential for maintaining the ecosystem that supports the mining environment and, consequently, for the operation itself that uses water resources. As an area that has such a finite resource as a basic operating condition and that uses this resource on a large scale, it is necessary to constantly seek to optimize its use, having as pillars quality and economy in the treatment of effluents generated. It is in stages like this that coagulating reagent work. In the processing unit in question, more than 90% of the water is recirculated and reused, a process that relies on the support of a coagulant to accelerate the sedimentation of solids and guarantee the reuse of water of sufficient quality to provide operations with the solvent necessary for the environment. physicochemical. The coagulant currently used in tailings dam operations is aluminum sulfate. Due to the high use and cost spent on this reagent, tests were conducted with two other alternative coagulants (iron III chloride and iron III sulfate), comparing the cost-benefit between the reagents assessed. To this end, a cost-benefit factor was used, calculated using the cost of the reagent, dosage, residual turbidity of the clarified liquid and the sedimentation speed of the solids. After the tests, it was found that aluminum sulfate, the reagent used in the operation until then, was the best option among the reagents assessed. However, a reduction of 21.43% in the dosage currently used of this reagent by the company, maintaining the final turbidity target is possible, thus generating cost reduction.

Removal of acephate and methamidophos from water: Coagulation and adsorptive treatment approaches

Pesticides has transformed the agricultural industry, primarily by enhancing productivity. However, the indiscriminate use of such compounds can adversely affect human health and disrupt ecosystem balance. Limited knowledge exists regarding the removal of these compounds from water, particularly for organophosphate pesticides when employing conventional treatment technologies. Therefore, this study aimed to assess the removal of acephate (ACE) and methamidophos (MET) - considered priority pesticides in Brazil - from waters with high and low turbidity during the clarification process carried out with aluminum sulfate (AS) and ferric chloride (FC), either alone or combined with powdered activated carbon (PAC) adsorption. All water samples were submitted to solid phase extraction (SPE C18 cartridges) prior to acephate and methamidophos analysis by HPLC MS/MS. The clarification process with either AS or FC coagulant did not efficiently remove acephate or methamidophos and maximum average removal (27 %) was observed with waters of high turbidity when using ferric chloride as coagulant. Addition of mineral PAC was also ineffective for removing both pesticides. However, the use of vegetable PAC (10 mg/L) resulted in better removal percentages, up to 80%, but only for methamidophos. The limited removal rates were attributed to the high hydrophilicity of acephate and methamidophos, along with their neutral charge at coagulation pH. These factors hinder the interaction of such organophosphorus pesticides with the flocs formed during coagulation as well as with PAC surface.

Combined extraction of manganese during water purification of technogenic solutions

A method for demanganization of technogenic aqueous solutions is presented. This method involves electrocoagulation purification of aqueous systems from high metal contents and extraction of manganese (II) ions by carbon sorbent adsorption. A coagulation technology based on electrogenerated aluminum hydroxide was used. According to diffraction analysis, such a hydroxide exhibits an amorphous porous hydrogel structure with a developed sorbing surface. The micellar structure of the as-generated aluminum hydroxide, which was attributed to a modification of gibbsite, is represented by the following colloidal particle: {[m Al(OH)3] nAl(OH)2+ (n-x) OH-}x+ xOH-. The associative process of sorption on gibbsite occurs by dispersion interaction, which is governed by the force of electrostatic attraction of instantaneous and induced dipoles of electrically neutral sorbent molecules and the [Mn (OH2)2(OH)2]0 manganese hydroxo-aquo complex. The adsorption limiting value of manganese ions amounted to 4.9 mmol/g at 298 K and pH 5.8, with the adsorption equilibrium constant reaching 1.36 . 104. The electricity consumption corresponded to 12.0 А.h at an optimal electrocoagulation duration of 15 min and a current density of 1.6 мА/сm2. The final purification of aqueous solutions using carbon sorbents was conducted in a slightly alkaline medium at pH 7.5. The manganese sorption value reached 1.68 mmol/g. Therefore, the resource-saving effect of processing of technogenic hydro-mineral solution is manifested in a significant reduction of heavy metal salts and in obtaining of demanded mixed coagulants of aluminum and iron sulfates from water purification wastes. Another positive effect of electrochemical water purification consist in water disinfection and its improved ogranoleptic parameters.

Preparation and properties of hexafluorosilicic acid series accelerators

Shotcrete technology has been widely used in tunnel engineering, road repair, underground engineering, and other scenarios due to its advantages of simple construction and fast progress. Liquid alkali-free accelerator is a necessary additive used in sprayed concrete, which can quickly set the concrete in a short period of time. Therefore, the development of alkali-free liquid accelerator is of great significance. The purpose of this research is to obtain low-cost and high-performance accelerator products and explore the influence of aluminum sulfate, hexafluorosilicic acid, and other raw materials on performance and stability. The main research results are as follows: (1) The accelerator product with low cost and high performance has been prepared. Its aluminum sulfate content is about 43%, hexafluorosilicic acid content is about 17%, sodium aluminate content is about 21%, the initial setting time is 1′ 15″, the final setting time is 2′ 05″, and the 1-day compressive strength is 9.5 MPa. (2) F ion plays a solubilizing role in the solution, and the appropriate ratio of aluminum sulfate and fluorine ion can greatly enhance the stability of accelerator solution. (3) Under the same cost condition, the influence of aluminum sulfate on the condensation performance is far greater than that of hexafluorosilicic acid and sodium metaaluminate. Subsequent research and development should focus on how to effectively increase the solubility of aluminum sulfate.

Produce low-CO2 sustainable cement–slag binder incorporating aluminum sulfate

Using slag to produce low-carbon building materials is a sustainable strategy to recycle industrial byproducts. However, with a high clinker substitution rate, the delayed early strength development of slag–cement binders severely limits their applicability in practical engineering. This study investigated the mechanism of action by which aluminum sulfate promotes early strength. Its influence on hydration, microstructure, hydration products, mechanical properties, and CO2 emissions was investigated. The analysis indicated that aluminum sulfate accelerated the dissolution of C3S during the induction period, but the precipitation of a large amount of ettringite hindered further hydration. However, this hindering effect decreases as hydration continues. At a 1% dosage, the CO2 emission per unit strength is the lowest. At a 2% dosage, the early strength can be effectively increased by 38.01%. By comparison, alkali-free aluminum sulfate improves the sustainability and mechanical properties better than an alkaline accelerator (sodium carbonate).

Evaluation of the efficacy of tamarind as a coagulation assistant of aluminum sulfate for the removal of turbidity in water for human consumption

La coagulación es un proceso esencial en el tratamiento de aguas, por lo que requiere la adición de floculantes químicos. El objetivo de esta investigación fue evaluar la eficiencia de la pepa, cáscara y pulpa del tamarindo, como ayudante de coagulación de sulfato de aluminio para la remoción de turbidez en aguas para consumo humano. Se aplicó un diseño experimental completamente al azar 6Ax6B de dos factores: factor A: seis tratamientos; factor B: concentraciones aplicadas (correspondientes a las seis dosis) con tres repeticiones por tratamiento; se aplicó la metodología Cepis con pruebas de jarras (300 y 40 rpm en mezcla rápida y floculación) para evaluar la turbidez en seis concentraciones (25, 30, 35, 40, 45 y 50 mg/l), aplicado en muestras simuladas de 100 UNT, encontrando que el tratamiento 4 presentó un porcentaje de remoción (96.6%) reduciendo a una turbidez de 3.40 UNTM; por otro lado, los tratamientos 1, 2, 5 y 6 presentaron una diferencia no significativa, con porcentajes de remoción promedio de 57.12, 57.02, 61.70 y 67.73%, respectivamente; el tratamiento 3 presentó el valor más bajo de remoción. El tratamiento 4 presentó un valor superior a los demás tratamientos. Por esa razón, la pepa de tamarindo es eficiente en la potabilización de las aguas como ayudante de coagulación de sulfato de aluminio.

Combination of 70% ethanol and 2% potassium aluminum sulfate as a modified antibacterial disinfectant

Background: Mobile phones used by health-care workers can harbor pathogenic bacteria. Effective techniques are therefore needed to prevent bacterial transmission through mobile phones, including the development of new or modified disinfectants. Methods: In total, 100 swabs were collected from the mobile phones of health-care workers. All samples were directly cultured and incubated for 24 h at 37°C. The samples were divided into two groups (n = 50 each): one disinfected with 70% ethanol alone and the other with 70% ethanol containing 2% potassium aluminum sulfate (alum). Results: Bacterial growth before disinfection with 70% ethanol alone was observed in 92% of samples, which decreased to 66% after disinfection. With 70% ethanol plus 2% alum, bacterial growth before disinfection was 88%, decreasing to 16% after disinfection. The mean number of colonies before disinfection with 70% ethanol alone was 22.80 ± 10.38, while after disinfection, it was 3.48 ± 1.40 (P &lt; 0.00001). Similarly, the number of colonies before disinfection with 70% ethanol plus 2% alum was 19.84 ± 9.34, while that after disinfection was 0.68 ± 0.33 (P &lt; 0.00001). Conclusion: To the best of our knowledge, this is the first study to evaluate the combination of 70% ethanol with 2% alum to enhance the antimicrobial efficacy of ethanol as a new modified disinfectant.

Growth rate of AL2O3 Thin Film by Liquid Phase Deposition as an Anti-reflection Coating Layer on Crystalline Silicon for Solar Cell Applications

The fabrication of photovoltaic (PV) device requires that surface reflectance of solar cells has to be minimized to achieve higher photo-conversion efficiency (PCE). Antireflection coating layer is deposited on the surface of a p-type crystalline silicon material to reduce the surface reflections of solar radiation and increase its absorption for efficient solar cell application. In this work, aluminum oxide thin film by liquid phase deposition (LPD-Al2O­3) is synthesized from combined solution of aluminum sulfate octadecahydrate (Al2(SO4)3·18H2­O) and sodium carbonate (NaHCO3) with pH of 3.1. Some samples of p-type (100) crystalline silicon (c-Si) wafers of resistivity 1 – 10 mΩ were immersed inside the growth liquid of LPD-Al2O­3 thin film for 1hr – 2.5 hours. This is followed by annealing the samples at a temperature of 450oC, the deposition rate is faster in the range 1 – 1.5 hours is about 35nm/hr. As the growth time increases, the growth rate of the film decreases and remains nearly constant at about 10 nm/hour at 1 – 2 hours. When the growth time exceeds 2 hours, the film thickness remains unchanged showing that the liquid has lost in growth ability. The weighted average reflection (%) of planar c-Si is reduced from 44.9 % to 29.6 % after deposition of the LPD-Al2O­3 for 2.5 hours growth time, indicating a 34.1 % reduction in reflection within wavelength region of 300–1100 nm. While the root means square (RMS) surface roughness of 36.5 nm was also recorded at the highest growth time of 2.5 hours. This shows the effect of thicker LPD-Al2O­3 thin film layer increases the anti-reflecting coating property of the material.

Growth rate of AL2O3 Thin Film by Liquid Phase Deposition as an Anti-reflection Coating Layer on Crystalline Silicon for Solar Cell Applications

The fabrication of photovoltaic (PV) device requires that surface reflectance of solar cells has to be minimized to achieve higher photo-conversion efficiency (PCE). Antireflection coating layer is deposited on the surface of a p-type crystalline silicon material to reduce the surface reflections of solar radiation and increase its absorption for efficient solar cell application. In this work, aluminum oxide thin film by liquid phase deposition (LPD-Al2O­3) is synthesized from combined solution of aluminum sulfate octadecahydrate (Al2(SO4)3·18H2­O) and sodium carbonate (NaHCO3) with pH of 3.1. Some samples of p-type (100) crystalline silicon (c-Si) wafers of resistivity 1 – 10 mΩ were immersed inside the growth liquid of LPD-Al2O­3 thin film for 1hr – 2.5 hours. This is followed by annealing the samples at a temperature of 450oC, the deposition rate is faster in the range 1 – 1.5 hours is about 35nm/hr. As the growth time increases, the growth rate of the film decreases and remains nearly constant at about 10 nm/hour at 1 – 2 hours. When the growth time exceeds 2 hours, the film thickness remains unchanged showing that the liquid has lost in growth ability. The weighted average reflection (%) of planar c-Si is reduced from 44.9 % to 29.6 % after deposition of the LPD-Al2O­3 for 2.5 hours growth time, indicating a 34.1 % reduction in reflection within wavelength region of 300–1100 nm. While the root means square (RMS) surface roughness of 36.5 nm was also recorded at the highest growth time of 2.5 hours. This shows the effect of thicker LPD-Al2O­3 thin film layer increases the anti-reflecting coating property of the material.

The effects of hardening accelerator on microstructure and mechanical performance of fly ash-cement-based materials using response surface methodology

To enhance the engineering application range of fly ash-cement-based materials (FCM), the combined effects of hardening accelerator on FCM were investigated by using response surface methodology (RSM). Based on a three-factor three-level Box-Behnken design (BBD), the linear, quadratic and interaction relationships between the dosages of calcium chloride (CaCl2), aluminum sulfate (Al2(SO4)3) and triethanolamine (TEA) on the primary properties (setting time, mechanical properties and shrinkage rate) of FCM were discussed. The prediction model was established to determine the optimal ratio of the composite system. The microscopic performance and the mineral fraction of the paste were explored by using X-ray diffraction (XRD), thermogravimetric differential scanning calorimetry (TG-DSC), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). Results indicated that the paste performance was affected by the interaction of multiple factors, and the interaction between CaCl2 and Al2(SO4)3 was the most significant. The optimum ratio of paste was 2.81 % CaCl2, 0.75 % Al2(SO4)3 and 0.12 % TEA, achieving a 28 d compressive strength of 40.48 MPa, closely matching the predicted value. The dominant hydration products of the composite cementitious system were C–S–H gel, AFt and Friedel's salt, with changes observed in the morphology of CH. With the prolong of curing age, the hydration products and unhydrated fly ash particles were bonded to each other, so that the slurry maintains a certain strength performance.

Advanced leachate treatment at Mascara landfill (Algeria): A hybrid pilot approach with activated sludge and ferric chloride

This study investigates a hybrid treatment approach, that combines a Sequencing Batch Reactor (SBR) with a coagulation-flocculation process, to reduce the contaminants in Landfill Leachate (LL), targeting Chemical Oxygen Demand (COD), Turbidity, and Total Suspended Solids (TSS). The experimental set-up incorporated a batch reactor at room temperature and a pH between 7.7 and 8.7, with an Arduino monitoring system for heightened precision. The SBR was operated continuously over a 24-hour cycle, with a Hydraulic Retention Time (HRT) set at 5 days and variable sludge retention times (SRT) of 5, 10, and 15 days. The Aluminum sulfate (Al2 (SO4)3), Ferric Chloride (FeCl3), and Lime (CaO) were assessed for the coagulation-flocculation process. The results indicate a promising removal efficiency of 40 % for COD, 31 % for turbidity, and 47 % for TSS using the SBR process. FeCl3 showed higher findings, achieving removal yields of 87 % for COD and 86 % for turbidity, at an optimized dose of 10 g/L and pH 5.5. Furthermore, adding 0.25 g/L of CaO significantly improved the removal efficiency to 94.14 % for COD, 98.22 % for turbidity and 99.78 % of the TSS. Therefore, this study's results underline the effectiveness of combining SBR with coagulation-flocculation, particularly using FeCl3 and CaO, in treating landfill leachate.

Brilliant green and methyl violet 2B dyes removal using aluminium sulfate (AS) in single and binary systems

This study aims to evaluate the removal of Brilliant Green (BG) and Methyl Violet 2B (MV2B) dyes using aluminum sulfate (AS) in single and binary coagulation-flocculation systems. Several factors were considered in the experimental runs, including AS dosage (5–150 mg/L), initial dye concentration (1–50 mg/L), and pH level (2−10). To improve the effectiveness of AS, some coagulants aid were added to the combined coagulation-flocculation process, including activated carbon (PAC) (0–2 g/L), calcium hydroxide (Ca(OH)2) (0–2 g/L), and polymer (0–0.2 mg/L). According to the experimental results, 60 mg/L of aluminum sulfate was the optimum dose for BG (57.39 %) and MV2B (32.45 %) removal at 30 mg/L of initial dye concentration without pH adjustment. The removal of BG and MV2B was reduced more in the acidic and alkaline solutions (pH levels 2 and 10), which was estimated by 64.8 % (pH 2) and 70.25 % (pH 10) for the BG and 45.35 % (pH 2) and 45.52 % (pH 10) for the MV2B. Moreover, the increase in the initial dye concentration leads to decreased treatment efficiency. The combination of AS with coagulants aid confirmed that the CAP obtained high removal efficiency. Whereas, in the binary system, the results with the different coagulant doses confirmed that the maximum efficiency colour removal was obtained, in the binary system with AS alone at (pH of 5.3 and 30 mg/L of the initial dye concentration of each dye), for two optimum doses, which are 130 mg/L and 25 mg/L for BG and MV2B, respectively. The removal efficiency of BG is more considerable than MV2B. Overall results suggest that the coagulation-flocculation of dyes in binary systems could be considered an effective process with socioeconomic and environmental benefits and can give more efficiency in the presence of another process.

Green Approach for Water Treatment

The common first step for water treatment is removing the particulate impurities by coagulation and flocculation. The conventional treatment uses polyvalent salts such as aluminum sulfate, iron (III) chloride, and synthetic polymers as coagulating agents which leads to potential toxicity. The purpose of this study is to identify environmentally friendly natural products as coagulant agents for water treatment. Four plant seeds (Amaranth, chia, quinoa, and wheat germ), corn cob, orange peel, and avocado peel were tested. Turbidity measurements were conducted with a wireless, portable turbidity sensor. Data was collected on a smartphone. The performance of the turbidity sensor was evaluated by preparation of a calibration curve (r2 = 0.9928). Results show that all four plant seeds and avocado peel demonstrated the ability to decrease the turbidity of the water sample. Among the four seeds that were studied, Amaranth and chia were identified as the top two natural coagulant agents. Inter-day and Intra-day studies were performed for the turbidity measurements. The relative standard deviation (RSD) was found to be less than 10%, indicating the method has good precision. The method can serve as a point-of-use water treatment in remote areas of developing countries with limited resources.

Microplastics removal from natural surface water by coagulation process

The present study aimed to compare the efficiency of microplastic removal from natural surface water by coagulation with ferrous and aluminum sulfate in the presence and without the selected coagulant aids. Coagulation with Fe(II) and Al(III) sulfates at doses conventionally used for drinking water treatment (10 – 80 mg.L−1) was effective in polystyrene and polyvinyl chloride removal. Fe(II) salts showed up to 5 % efficiency higher in microplastic removal under the conditions of the experiment. The addition of the flocculating agent to support the aggregation of flocs allowed for the improvement of microplastic removal efficiency at the same dose of up to 10 %. Based on the results, flocculating agents are recommended for microplastic removal. Coagulation without flocculating agent amendment is enough to remove most microplastics if filtration is applicable.

Optimasi Dosis Koagulan Aluminium Sulfat Al2 (SO4)3 Pada Ipam PT Hanarida Tirta Birawa Sidoarjo

In drinking water treatment plants, there is a coagulation unit that requires coagulant substances. Coagulant dosage determination can be done using the jartest method. By carrying out a jar test, the correct dose will be known so that the coagulation process runs well, and the use of coagulants can be optimized. This research was carried out by analyzing jartest results from the company's internal laboratory for one week with two variations in jartest times in one day. The raw water used comes from shipping rivers with a company production capacity of 500 l/second. The dosage of Aluminum Sulphate coagulant used in the field is 165 mg/l, while the jastest results show that the optimum dosage is 140 mg/l. This research is expected to provide scientific information regarding determining coagulant dosage at IPAM PT Hanarida Tirta Birawa which makes it easier for installation operators.

Enhanced removal of lead and zinc by a 3D aluminium sulphate-functionalised graphene aerogel as an effective adsorption system

The discharge of heavy metals into the environment has adversely affected the aquatic ecosystem due to their toxic and non-biodegradable nature. In this research, a three-dimensional graphene oxide/carboxymethylcellulose/aluminium sulphate (GOCAS) aerogel was synthesised and evaluated as a novel means for lead and zinc removal. The GOCAS aerogel was prepared via ice-templating of graphene oxide with carboxymethylcellulose and aluminium sulphate as the crosslinking and functionalisation additives. Characterisation of the aerogel by various analytical techniques confirmed the successful integration of the chemical additives. The hydroxyl and sulphate groups in the aerogel were found to participate in the adsorption of both metals. The equilibrium of lead adsorption was found to correlate well to the Freundlich isotherm, while zinc adsorption fitted closely the Langmuir isotherm. The kinetic adsorption behaviour of both metals was best described as pseudo-second-order. The interactive influences of concentration, temperature, contact time and adsorbent dose on the metal removal were explored by a central composite design, and the optimum adsorption capacity for lead was determined to be 138.7 mg/g at a GOCAS dose of 20 mg, initial concentration of 100 mg/L, temperature of 50 °C and contact time of 45 min. The optimum adsorption capacity for zinc was 52.69 mg/g at 30 mg, 65 mg/L, 45 °C and 40 min. Furthermore, regeneration studies with hydrochloric acid eluant were successfully conducted for up to four adsorption-desorption cycles. Overall, this work demonstrates that GOCAS aerogel is a viable nanosorbent for the adsorption of lead and zinc from water systems.