Removal Of Anionic Surfactants Research Articles

Removal of anionic surfactant from aqueous solutions by adsorption onto biochars: characterisation, kinetics, and mechanism.

Biochar, a waste biomass-derived adsorbent, holds promise for decentralised wastewater treatment. However, limited research exists on its efficacy in adsorbing anionic surfactants in wastewater. To address this, the adsorption of sodium dodecyl sulphate (SDS), a common anionic surfactant, was studied using various biochar types: rice husk biochar (RH-550 and RH-700), wheat straw biochar (WS-550 and WS-700) produced at 550°C and 700°C, wood-based biochar (OB), and activated carbon (AC) as a control. The study investigated the impact of pH (3-9), adsorbent loading (1-10 g/L), adsorbent size (<0.5-2.5 mm), contact time (5-180 min), and initial concentration (50-200 mg/L) on SDS removal. Under optimised conditions (100 mg/L SDS, 4 g/L adsorbent, 1-2 mm particle size, pH 8.3, and 180 min contact time), maximum SDS removals were RH-550 (78%), RH-700 (82.4%), WS-550 (89.5%), WS-700 (90.4%), AC (97%), and OB (88.4%). Among the tested adsorbent materials, WS-550 exhibited the highest SDS adsorption capacity at 66.23 mg/g compared to AC (80.65 mg/g), followed by RH-550 (49.75 mg/g), OB (45.87 mg/g), RH-700 (43.67 mg/g), and WS-700 (42.74 mg/g). SDS adsorption followed a pseudo-second-order kinetic model, indicating chemisorption on the adsorbent surface. The Freundlich isotherm model exhibited a better fit for the experimental data on SDS adsorption using all tested adsorbents except for RH-550. This study showed that biochars produced from agricultural and forestry residues are effective adsorbents for SDS in aqueous solutions and can be a promising sustainable and low-cost material for the treatment of greywater containing anionic surfactants (e.g. handwashing, laundry, kitchen, and bathroom greywaters).

Integrating of electrocoagulation process with submerged membrane bioreactor for wastewater treatment under low voltage gradients

Treating and reusing wastewater has become an essential aspect of water management worldwide. However, the increase in emerging pollutants such as polycyclic aromatic hydrocarbons (PAHs), which are presented in wastewater from various sources like industry, roads, and household waste, makes their removal difficult due to their low concentration, stability, and ability to combine with other organic substances. Therefore, treating a low load of wastewater is an attractive option. The study aimed to address membrane fouling in the submerged membrane bioreactor (SMBR) used for wastewater treatment. An aluminum electrocoagulation (EC) device was combined with SMBR as a pre-treatment to reduce fouling. The EC-SMBR process was compared with a conventional SMBR without EC, fed with real grey water. To prevent impeding biological growth, low voltage gradients were utilized in the EC deviceThe comparison was conducted over 60 days with constant transmembrane pressure and infinite solid retention time (SRT). In phase I, when the EC device was operated at a low voltage gradient (0.64 V/cm), no significant improvement in the pollutants removal was observed in terms of color, turbidity, and chemical oxygen demand (COD). Nevertheless, during phase II, a voltage gradient of 1.26 V/cm achieved up to 100%, 99.7%, 92%, 94.1%, and 96.5% removals in the EC-SMBR process in comparison with 95.1%, 95.4%, 85%, 91.7% and 74.2% removals in the SMBR process for turbidity, color, COD, ammonia nitrogen (NH3–N), total phosphorus (TP), respectively. SMBR showed better anionic surfactant (AS) removal than EC-SMBR. A voltage gradient of 0.64 V/cm in the EC unit significantly reduced fouling by 23.7%, while 1.26 V/cm showed inconsistent results. Accumulation of Al ions negatively affected membrane performance. Low voltage gradients in EC can control SMBR fouling if Al concentration is controlled. Future research should investigate EC-SMBR with constant membrane flux for large-scale applications, considering energy consumption and operating costs.

Improving the Removal of Anionic Surfactant in Cardboard Industry Wastewater by Coagulation/Flocculation: Process Optimization with Response Surface Methodology

Response surface methodology (RSM) and Box–Behnken design (BBD) were investigated to optimize the coagulation–flocculation process (CF) of cardboard industry effluent using polyaluminum chloride (PAC) and cationic polyacrylamides (c-PAM). The aim is to identify the optimum combination of coagulant dose, pH, and flocculant dosage for the highest removal efficacy of chemical oxygen demand (COD) and anionic surfactant removal. According to the results, COD reduction was principally controlled by PAC and c-PAM, while anionic surfactant was affected by pH and PAC. In addition, COD and anionic surfactant removal models fitted well with the experimental results (R2 > 0.85). Coagulation/flocculation using optimum conditions of pH, PAC, and c-PAM led to the total removal of anionic surfactant and the reduction of more than 95% of COD.

High surface area mesoporous activated carbon produced from Iraqi reed via pyrolysis assisted H3PO4 activation: Box-Behnken design for surfactant removal

Herein, pyrolysis assisted H3PO4 activation was employed to produce activated carbon (AC) from Iraqi reed (IR) biomass waste. After pyrolysis assisted H3PO4 activation of IR, the BET surface area dramatically improved (0.5542 m2/g for IR to 1045.18 m2/g for IRAC). The removal of a model anionic surfactant (sodium dodecyl benzene sulfonate, SDBS) by IRAC was studied. Box-Behnken design (BBD) was implemented to investigate the critical adsorption factors (A: dose, 0.02–0.1 g; B: pH, 4–10; C: time, 30–120 min). Adsorption kinetics and equilibrium adsorption data revealed that SDBS adsorption by IRAC fits the pseudo-second order and Langmuir models for kinetic and equilibrium conditions, respectively. The maximum adsorption capacity (qmax) of IRAC for SDBS was specified to be 121.5 mg/g. This study demonstrates the utility of IR as a biomass precursor for the efficient synthesis of IRAC and its application for removal of anionic surfactants from industrial effluent.

A new and low-cost surface-functionalized corn straw adsorbent for adsorptive removal of sodium dodecylbenzene sulfonate: Adsorbent preparation and adsorption performance

Utilization of greywater can relieve the pressure of water scarcity. However, the widespread presence of anionic surfactants in greywater poses threats to the environment and the health of the human and ecosystem. In this study, bioinspired polyethyleneimine-tannic acid (PEI-TA) complexes were innovatively used for coating of corn straw (CS) and the as-prepared PEI-TA modified CS (PEI-TA@CS) was applied for adsorptive removal of the commonly found sodium dodecylbenzene sulfonate (SDBS) in greywater. The adsorption performance of the modified CS was maximized under the following optimized preparation conditions: 5 g/L of PEI concentration with molecular weight of 3000 Da, 0.5 g/L of TA concentration and 3 h of modification time. Investigation of the adsorption conditions showed that adsorption of SDBS on the adsorbent were pH-independent at pH ≤ 7 and the adsorption process reached equilibrium in about 3 h. The pseudo-second-order model and Freundlich model fit well the kinetic and isotherms data, respectively, and the nature of the adsorption was exothermic and spontaneous. Mechanism analysis showed that the adsorption of SDBS was dominated by hydrophobic interactions. With a dosage of 100 mg, PEI-TA@CS could satisfactorily remove 94.95 % of SDBS from its aqueous solution (50 mg/L). Even in the complex synthetic greywater, the removal of SDBS still reached as high as 81.99 %. The overall results indicated that PEI-TA@CS has promising applications in the removal of anionic surfactants from greywater.

Sequential biological and solar photocatalytic treatment system for greywater treatment.

In this study, sequencing batch reactor (SBR) using anaerobic/aerobic/anoxic process was coupled to a solar photocatalytic reactor (SPCR) for greywater treatment. The greywater effluent from SBR (operated at the optimal condition: 6.8 h hydraulic retention time (HRT), 0.7 Volumetric exchange ratio (VER) and 7.94 d solids retention time (SRT) with optimal corn cob adsorbent dosage (0.5 g/L)) was fed to the SPCR (operated at optimal conditions: pH - 3, H2O2 dosage - 1 g/L, catalyst dosage - 5 g/L). Chemical oxygen demand (COD) removal of 92.8±0.5% and ∼100% were achieved in SBR and SBR-SPCR, respectively. Similarly, total organic carbon (TOC) removal of 91±0.9% and ∼100% were observed in SBR and SBR-SPCR, respectively. After SBR treatment, average total nitrogen (TN) removal of 84% was found and this TN removal increased to 93% after combined SBR-SPCR treatment. The maximum PO43-_P reduction of 80±1.5% % was achieved with SBR-adsorption system. In addition, a maximum of 87±0.9% of net PO43-_P removal was reached after SBR-SPCR treatment. 58.9±2.3% BP (benzophenone-3) removal was obtained in the SBR while the integration of SBR and SPCR treatment was resulted in 100% BP removal. An effective anionic surfactant (AS) removal rate (80.1±2.2%) was observed in the SBR phase, which further improved to 94.9±1% at the end of 4 h SPCR treatment.

Enhancement of Fenton Performance at Near-Neutral pH by Using Ethylene Diamine Tetra Acetic Acid for Anionic Surfactant Removal from a Laundry Wastewater

Fenton process involving Fe2+ ions and H2O2 produces OH radicals, that act as a strong oxidizing agent for degradation of a variety of organic pollutants. However the process is poor performance at neutral pH limiting its application for industrial wastewater treatment. The short coming problem, in the current study, is solved by introducing ethylene diamine tetra acetic acid (EDTA) as a complexing compound. The degradation was conducted through batch experiment, by varying EDTA concentration and pH. In addition, the Fe2+ and H2O2 concentrations, and the reaction time were optimized. The research results assign that the addition of EDTA could remarkably enhance the degradation of anionic surfactant, that was 96% at pH 6-8. The increase of the degradation was proportional to the concentrations of EDTA and 6 mg/L showed the optimum level. The highest degradation of 162 mg/L anionic surfactant in 20 mL of the laundry wastewater could be achieved within 30 mins by using Fe2+ 10 mM, H2O2 50 mM, and in the pre12sence of EDTA 6 mg/L at pH 7. Key words : Fenton, EDTA, degradation, surfactant, wastewater

Production of magnetic sewage sludge biochar: investigation of the activation mechanism and effect of the activating agent and temperature

Sewage sludge-based porous materials were prepared through an integrated and energy-saving procedure that combines chemical activation with an alkali (NaOH or K2CO3) and physical activation with CO2 in a single step. The study was conducted in a wide temperature range (600–1000 °C), using higher temperatures than those commonly used. From the standpoint of textural properties, the impregnation results in a decrease in the optimum activation temperature: 800 °C for untreated samples, and 600–700 °C for impregnated samples. The impregnation increases the amount of –OH and –NH functional groups, and it also leads to the generation of new oxygen- and/or nitrogen-containing functionalities (above 800 °C for the impregnation with K2CO3 and in the whole temperature range for the impregnation with NaOH). The chemical treatment favors the development of magnetic properties on biochars, which is an advantage for its reuse in wastewater treatment, since it favors the removal of anionic surfactants and heavy metals such as lead, copper, zinc, and manganese. The uptake of phenol and methylene blue (MB) is maximized with the combination of the impregnation (with NaOH for phenol and K2CO3 for MB) and the use of a moderate temperature (600–700 °C). The optimum uptake values represent an increase of 87% and 152% for MB and phenol, respectively, compared to the highest value of non-impregnated samples (activated at 800 °C), with the advantage of the lower temperature required.Graphical abstract

Sodium Lauryl Sulphate removal using copper electrodes without and with perforations by electro coagulation process

The present investigation aims to study the removal of anionic surfactant (Sodium Lauryl Sulphate) from by the electrocoagulation method using copper electrodes without and with perforations from an aqueous solution. Different series of experiments were carried out to study the effect of each of NaCl concentration, pH, voltage, electrolysis time and initial surfactant dose on removal of anionic surfactant (SLS). The experimental results showed that the anionic surfactant (SLS) in the aqueous solution was effectively removed by electrocoagulation process. From the obtained optimal conditions the removal efficiency of anionic surfactant SLS by copper electrodes without and with perforations were 64.75% and 74.30% respectively at NaCl concentration of 1.5gL-1, pH 7, voltage 20 V, time 40 min and initial dose of surfactant of 25mgL-1-150mgL-1. The FT-IR analysis were also performed for the treated aqueous solution. The kinetics and energy consumption studies were also observed. Results indicated that the pseudo second order equation is the most suitable model for the system.

Removal of Anionic Synthetic Surfactants from Petrochemical Enterprises Wastewater Using Carbonate Sludge

Removal of Anionic Synthetic Surfactants from Petrochemical Enterprises Wastewater Using Carbonate Sludge

Technical and economical viability of a graywater recycling system employing an integrated preliminary settlement and filtration process

AbstractThe collection and reuse of graywater has become an important strategy for achieving the goal of sustainable development. In this work, an integrated preliminary settlement and filtration process was developed for treating shower water which was obtained from a college bathroom toilet. The system's pollutant removal efficiency was examined for three different filter media: manganese sand, quartz sand and ceramsite. The results showed that for ceramsite, the average removal of turbidity, CODcr, NH3-N, and anionic surfactant was 93.3%, 68.6%, 78.9, and 83.5% respectively. For manganese sand, the values were 84.6%, 61.5%, 57.8 and 59%, while for quartz, they were 88.9%, 47.9%, 39.5% and 51.9%. A cost–benefit analysis revealed that the payback period of graywater recycling systems ranges from 3.16–5.30 years and benefit–cost ratios are in the range of 1.23–1.67, depending on tank size. The proposed system provides a new strategy for enhancing water-use efficiency in buildings in a more decentralized way.

Evaluation of Parameters in the Removal of Linear Alkylbenzene Sulfonate Anionic Surfactant Using Electrocoagulation

The objective of the present investigation was to construct an electrocoagulation cell in a batch system and to evaluate its capacity to remove the anionic surfactant of the linear alkylbenzene sulfonate (LAS), which is present in gray water determining the effect of the type of electrodes (Al or Fe), distance between electrodes (1, 1.5 and 2 cm) and voltages (10, 15 and 20 V). The experimental tests were carried out for 20 min. The dimensions of the short wave electrolysis cell built in glass were 26 cm long, 7 cm wide and 12 cm high, with 10 electrodes of 12x6 cm supported by a PVC structure. The concentration of LAS in the solution was determined by employing UV-Vis spectrometry applying the Methylene Blue Active Substances (MBAS) method. A higher removal of 65.55% was obtained when aluminum electrodes were used, and 69.11% with iron electrodes a separation of 1.5 cm and a voltage of 20 V, presenting less change in pH, conductivity, and energy consumption when using the Al3 electrode. When evaluating the effect of time at the best experimental configuration (Al, 1.5 cm, 20 V) it was established that the removal efficiency increased to 75.13% in 60 min. Electrocoagulation with aluminum electrodes is presented as an efficient alternative for the removal of LAS in solution.

Optimization of synthesis of geopolymer adsorbent for the effective removal of anionic surfactant from aqueous solution

This paper describes the optimization of synthesis of fly ash based geopolymer (FAGP) for removing the anionic surfactant sodium dodecylbenzene sulfonate (SDBS) using response surface methodology (RSM) by varying the synthesis parameters of silica to alumina (Si/Al), sodium to alumina (Na/Al) and water to solid (W/S) ratios with the adsorption capacity as the response. The geopolymer samples were designed, synthesized, characterized, used for removing SDBS surfactant, and regenerated. Surface area and pore size analysis, Fourier Transform Infrared Spectroscopy (FTIR) analysis, phase analysis, and microstructural analysis confirmed the synthesis of mesoporous and amorphous geopolymers with the presence of pores, cavities and rods in the geopolymer structure. Geopolymer sample synthesized with the composition of Si/Al-2.87, Na/Al-1.0 and W/S-0.35 (FAGP-2) achieved maximum surface area of 59.512 m2/g and displayed the highest adsorption capacity of 743.706 mg/g and removal efficiency of 84.5%. The ANOVA analysis showed a correlation coefficient (R2) of 0.952, F-value of 22.27, and p value of 0.05 which indicated the significance of the model and lack of fit was non-significant which showed good fitting of the experimental data to the quadratic model with 95% confidence level. The proposed geopolymer composition of Si/Al-2.353, Na/Al-1.056, and W/S-0.339 achieved adsorption capacity of 730.212 mg/g which is 99% similar to the predicted adsorption capacity. Thermal method successfully regenerated SDBS adsorbed geopolymer with only 13.8% loss of adsorption capacity after five cycles of regeneration. The adsorption capacity of optimized geopolymer is higher than other adsorbents such as cross-linked chitosan films, commercial activated carbon, surface functionalized mesoporous silica nanoparticles, multi-walled carbon nanotubes (MWCNTs), and others used for removing SDBS surfactant and only amino crosslinked chitosan microspheres (ACCMs) has higher adsorption capacity than geopolymer. This shows that geopolymer can also be effectively used to adsorb SDBS surfactant from wastewater.

Adsorption Kinetics, Isotherms, and Thermodynamics of Removal of Anionic Surfactant from Aqueous Solution Using Fly Ash

Surfactants are organic compounds which can be used in several applications. However, they can contaminate world water resources causing detrimental effects to human beings, aquatic life, and animals. This paper investigates the adsorption kinetics, isotherms, and thermodynamic properties for the removal of an anionic surfactant, sodium dodecylbenzene sulfonate (SDBS), using fly ash. Characteristics of fly ash such as surface area and pore size analysis and the point of zero charge (PZC) were determined. The effects of parameters such as pH, surfactant concentration, and temperature and the adsorption kinetics, isotherms, and thermodynamic properties and adsorption mechanism were determined. Fly ash is a mesoporous material having surface area and pore size of 1.079 m2/g and 9.813 nm and PZC at pH 6.58. pH 2 and the temperature 25 °C were optimum for adsorbing SDBS onto fly ash. The adsorption capacity and removal efficiency increased by increasing the concentration of SDBS from 100 to 2000 mg/L, indicating that the increase of surfactant concentration could not saturate the surface of fly ash. The pseudo-second-order and the Langmuir isotherm models showed best fit to the adsorption data and the thermodynamic properties described adsorption as an exothermic, barrierless, non-spontaneous, and entropy-reducing reaction which is more feasible at a lower temperature of 25 °C. This indicated that the adsorption occurs by both physisorption and chemisorption with monolayer coverage of SDBS on the surface of fly ash. SDBS surfactant adsorbed onto fly ash mainly through electrostatic interactions between oppositely charged SDBS and fly ash.

Evaluation of optimal conditions for anionic surfactant removal in wastewater

This study was conducted to find the optimal conditions for removing anionic surfactants in wastewater using the coagulant-flocculant method. Optimal conditions must be found to minimize the amount of metal materials that can cause secondary contamination and to improve performance. Five parameters were selected to investigate their influence on surfactant removal. The ranges of the independent variables were 0.5–5% for coagulant concentration, 0.1–1% for flocculant concentration, and 20–650 mg/L for surfactant concentration; the coagulant type was FeCl3·6H2O or Ca(OH)2; and the pH ranged from 2 to 10. The experimental results were analyzed with Minitab 19.1 to find the optimal conditions to maximize the removal rate of surfactant. In this study, a total of 20 experiments were carried out using a half fractional factorial design (FFD) including two center points with a resolution of 5 and a pseudo-center point. The results demonstrated that coagulant concentration, flocculant concentration, and pH were significant independent variables with respect to surfactant removal. The fitted regression equation confirmed that the surfactant removal rate was maximized when the coagulant concentration was 5%, the flocculant concentration was 0.1%, and the pH was 10.

Micropollutant Removal from Laundry Wastewater in Algal-Activated Sludge Systems: Microbial Studies

The main objective of this research was to study the feasibility of using algal and algal-activated sludge systems in treating laundry wastewater. Three different types of systems—green microalgae (system A), diatoms + activated sludge (system B), and green microalgae + activated sludge (system C)—were studied at six different solid retention times (SRT)—6, 8, 10, 12, 14, and 16 days—to evaluate their performance in removal of total organic carbon (TOC), total nitrogen (TN), anionic surfactants, and micropollutants with added trace elements. System B showed relatively better performance in removal of TOC (79%) and TN (90%). A total of 64 compounds were detected in influent when analyzed by LC-MS, of which 19 were grouped under herbicides, pesticides, and insecticides, 25 under pharmaceuticals, and 20 under others. Linear alkylbenzene sulfonate (LAS) was detected only in the effluent of system A and was not detected in both system B and system C. Grotan OX, an anti-microbial, was the compound with least removal in all the systems. The bacterial LAS degrader/tolerant plate count in system B at 16-day SRT was 2000 CFU/mL, 50 times more than the plate count of system C (40 CFU/mL). The LAS degrader/tolerant bacterial species identified were Aeromonas caviae and Klebsiella pneumonia in both systems B and C. The LAS degrader/tolerant green microalgae plate count at 16-day SRT was 130 CFU/mL, whereas no LAS degrader/tolerant diatom colonies were observed.

Mechanistic Modeling and Process Design for Removal of Anionic Surfactant Using Dolochar

Abstract The rapid rise in consumption of surfactants day by day and the consequent increase in discharge from both industrial and residential areas into bodies of water has become a cause for conc...

Removal of non-ionic and anionic surfactants from real laundry wastewater by means of a full-scale treatment system

Surfactants are considered emerging contaminants, that can represent a source of problems for environment and human health. This paper aims to quantify the effect of a thermophilic aerobic membrane reactor (TAMR), nanofiltration (NF) and adsorption on activated carbon (AC) for the removal of non-ionic surfactants (TAS) and anionic surfactants (MBAS) from a real laundry wastewater. This study included daily monitoring of a full-scale plant for more than three months. The results showed that the TAMR process has been able to withstand high stress conditions (sudden load peaks) and resist to a high concentration of surfactants, allowing it to perform an effective pre-treatment activity. Both in the case of the removal of TAS and of MBAS, the combination of processes made it possible to obtain higher removal yields. Evaluating the operating costs, the results suggested that TAMR+NF represented the optimal combination of processes for the removal of TAS and MBAS. The TAMR+NF+AC sequence allowed almost complete removal of TAS (> 95%) and high removal of MBAS (> 76%) but the costs per unit of mass removed were high.

Removal of anionic surfactants from aqueous solutions using Fe-aluminosilicate sorbents

Fe-aluminosilicate sorbents were obtained by modifying bentonite clay with iron polyoxocations and heat treatment at 400°C and 500°C. The specific surface of the sorbents determined by the method of low-temperature nitrogen adsorption was 118-136 m2 · g–1. The iron content in sorbents was equal 7.8 %. The adsorption properties of the obtained sorbents were studied with respect to anionic surfactants (sodium dodecyl sulfate and sodium dodecylbenzenesulfonate) in aqueous solutions. It was shown that the modification of clay leads to a significant increase in anion-exchange capacity. The value of the adsorption capacity was in good agreement with the increase in the number of the basic groups of Fe – OH and the value of the specific surface of the sorbents. Adsorption isotherms of sodium dodecyl sulfate on bentonite clay and on Fe –aluminosilicate sorbents are described by the Langmuir adsorption isotherm equation which describes monolayer adsorption on a homogeneous surface with a correlation coefficient of 1.000 at initial surfactant concentrations of 10-1000 mg · l–1. The adsorption capacity of Fe-aluminosilicate sorbents was more than 3 times higher than the capacity of the original clay in the adsorption of sodium dodecyl sulfate and was about 5 times higher in the adsorption of sodium dodecylbenzenesulfonate. The results of the study suggest that the Fe-aluminosilicate sorbents can be effective for removing anionic surfactants from wastewater.

Removal of Anionic Surfactant from Residential Laundry Wastewater using Jackfruit (Artocarpus heterophyllus) seeds

The study presented in this article investigated the removal of a long chain anionic surfactant from residential laundry wastewater using jackfruit (Artocarpus heterophyllus) seeds. The main ingredients of laundry wastewater are the surfactants. Therefore, great attention should be given to the treatment and disposal of laundry wastewater. The use of natural substitutes in treating wastewater has no harmful effects, and it is considered an effective step towards protecting the environment and promoting sustainability. Jar test experiments were conducted in order to determine the optimum conditions for the removal of surfactants, chemical oxygen demand (COD), biological oxygen demand (BOD), turbidity in terms of effective dosage, and pH control. The surfactant, COD, BOD, and turbidity removal efficiencies were 91.66%, 82.86%, 77.66%, and 85.14% at the optimum initial pH value of 6, the optimum dose of 2.5 g/L, and optimum mixing time of 25 minutes, respectively. It can be concluded that Artocarpus heterophyllus seed powder was a feasible and cost-effective natural coagulant for the removal of anionic surfactant from laundry wastewater. The results showed that the pseudo-second-order equation is the suitable model for this system.