Water Treatment Agent Research Articles

Polyrhodanine-Functionalized Magnetic-Activated Carbon for Efficient Removal of Lead Ions and Malachite Green From Wastewater

The development of wastewater treatment agents with high treatment capacity and efficient separation is crucial for the remediation of heavy metal ions and organic dye wastewater. In this study, a polyrhodanine functional magnetic-activated carbon composite (PR-mAC) was synthesized via a one-step co-precipitation method combined with chemical oxidation polymerization. As an innovative water treatment agent, PR-mAC possesses not only environmentally friendly and easily obtainable raw materials but also magnetic properties that facilitate its reusability. Notably, PR-mAC exhibited remarkable removal efficiency towards lead ion (Pb(II)) and malachite green (MG). Experimental results demonstrated that the adsorption of Pb(II) and MG followed quasi-second-order kinetic model, while the Hill isothermal adsorption model and Redlich–Peterson isothermal adsorption model were suitable for Pb(II) and MG removal, respectively. All adsorption processes were spontaneous endothermic reactions. The maximum adsorption capacities reached 223.71 mg/g and 315.46mg/g, respectively. Even after undergoing 5 cycles, the material maintained satisfactory removal performance for Pb(II) and MG pollutants. Therefore, the prepared PR-mAC represents an optimal agent for wastewater treatment due to its effective capability in removing both metal ions and dyes.

Development of the method for obtaining and studying vitriol of the iron sulphate based on iron-containing wastes

Especially in recent years, a ferric sulfate solution has occupied the attention as a useful water treatment agent and, particularly, a ferric sulfate solution and a basic ferric sulfate solution have a quick sedimentation speed for the resulting flocs and show good deodorizing ability as compared with a water treatment agent of an aluminum type such as an aluminum sulfate solution and la basic aluminum chloride solution whereby they have been widely used as a water treatment agent for waste water from paper manufacturing industry, from food industry, from chemical industry, leather industry. The purpose and task of the research is to develop the technology for the production of iron sulfate salts. For this purpose used iron filings and sulfuric and hydrochloric acid acid were used for this purpose. Processes of dissolution of ferric waste in acid are well studied and are shown.

Study on synthesis and properties of environmental protection water treatment agent

The copolymers were obtained by a water-based polymerization reaction using maleic anhydride and acrylic acid as the main raw materials. And the scale inhibition performance of the resulting scale inhibitor was investigated by static scale inhibition experiments. The experimental results proved that the scale inhibitor has good scale inhibition performance for calcium carbonate and calcium sulfate. When the dosage is 100mg/L, the scale inhibition rate of the agent reaches 100%. This avoids the hidden danger of affecting normal production due to system scaling.

In situ green synthesis of copper-loaded chitin/hydroxyapatite hydrogels for efficient catalytic reduction of 4-nitrophenol

In this study, the in situ reduction of Ch/HA hydrogel with adsorbed Cu2+ was used for the efficient catalytic reduction of 4-nitrophenol, which provides a new idea for the reuse of water treatment agents and the reduction of secondary pollution.

The use of precipitation from water treatment plants

Urban water purification by sedimentation treatment is one of the important steps widely used in a large cities’ infrastructure. The waste of technology mentioned is a high-humidity sludge with a different mineral and biological composition and various particle size. Due to the presence of significant amounts of active fractions, these sediments can be secondary used as an additional water treatment agent. To explore this statement in a more detail, the study presented deals with the natural-derived waste obtained through Rostov-on-Don urban water sedimentation treatment with aluminum sulfate Al2(SO4)3 and polycationite VPK-402. The following parameters were analyzed: humidity, density, mass and volume fractions of solid phases coupled with its chemical and physical characteristics. It is shown that the secondary utilization of the sediment produced will lead to treatment agents’ economy up to 30%.

Preparation of cellulose nanofiber/Fe3O4/CaCO3 magnetic biocomposite by air capture and its application on purifying lead-contaminated water: Removal, immobilization and separation

Utilizing nature resource is one of the most effective ways to achieve sustainability development. In this work, super low-concentration CO2 in the atmosphere and rich and cheap biomaterial cellulose were used to prepare magnetic bio-composite, cellulose nanofiber/Fe3O4/CaCO3 (CFeCa). By capturing CO2 in air, Ca2+ was transformed into calcite CaCO3, which subsequently coated on cellulose nanofiber (CNF). Fe3O4 with about 50 nm in size were also observed to attach to the CNF. Thus, CNF bridged these two inorganic materials, which together fabricated stable composite with strong mutual coupling. The prepared CFeCa was applied to purify the lead-polluted water as water treatment agent. Its up-taken capacity for Pb2+ reached as high as 1010 mg·g−1. Almost 100% removal efficiency was attained, even treating Pb2+ wastewater in a wide concentration range from 5 to 250 ppm. Meanwhile, CFeCa is stable property during application. After running for 30 cycles, the treated water still met drinkable water standard. More importantly, the recovered lead was also bound on the surface of CNF, which make it easy to be separated from water and avoiding the risk of second pollution. Cheap raw materials and multiple merits of resulted composite offer CFeCa a perspective application as water treatment agent.

Enrichment and immobilization of heavy metal ions from wastewater by nanocellulose/carbon dots-derived composite

Heavy metal ions (HMIs) have been widely applied in various industries because of their excellent physicochemical properties. However, their discharging without appropriate treatment brought about serious pollution problems. So it is desirable but challenging to rapidly and completely clean up these toxic pollutants from water, especially utilizing environmentally friendly and naturally rich biomass materials. In this work, we prepared nanocellulose/carbon dots/magnesium hydroxide (CCMg) ternary composite using cotton via a simple hydrothermal method. The removal mechanism towards Cd2+ and Cu2+ was investigated using a combination of experimental techniques and density functional theory calculations. CCMg shows a good ability to remove HMIs. It is realized that the interaction between each component of CCMg and cadmium nitrate is mainly of hydrogen/dative bonds. Cadmium nitrate is preferentially enriched by the Mg(OH)2 moiety, proved by calculated thermodynamics, interfacial interactions and charges. After transformation, the cadmium carbonate precipitate is fixed on the surface by nanocellulose (NC) via chemical coupling; and of interest is that copper ion precipitates in the form of basic sulfate. Due to its high adsorption effect and simple recovery operation, CCMg is having a wide range of application prospects as a water treatment agent.

A novel Chitosan-Barbituric acid hydrogel supersorbent for sequestration of chromium and cyanide ions: Equilibrium studies and optimization through RSM

The objective of this study is to transform chitosan biopolymer by crosslinking with barbituric acid into an amine-rich product that could be applied as a water treatment agent. Chitosan-barbituric acid (CBA) was synthesized by lyophilization process and characterized using FT-IR, XRD, TGA-DTA, SEM-EDX, BET surface area and BJH pore size distribution analysis. The pHpzc was found to be 7.7 indicating applicability towards both cations and anion adsorption. The CBA was used for seizure of CrVI and CN– from aqueous solutions in batch adsorption as well as fixed bed column experiments. Response surface methodology (RSM) was used as a statistical tool to optimize the functioning parameters resulting in more than 90 % removal of these ions. As shown by isotherm and kinetics data, Langmuir isotherm and pseudo second order kinetics exhibited a good fit for the adsorption process. The maximum adsorption capacities of CBA towards CrVI and CN– evaluated using Langmuir isotherm fitment were 534.75 mg g−1 and 251.66 mg g−1 at pH 4.0 and 6.0 respectively. Thermodynamic studies indicated spontaneous and enthalpy driven course with large negative enthalpy changes of −56.39 and −31.81 kJ mol−1 respectively. Fixed bed column studies showed that the material could be used for larger sample volume treatment even at 200 mg/L CrVI and 100 mg/L CN−1 concentration. Regeneration studies of adsorbent was conducted over five adsorption–desorption cycles with removal efficiency more than 50 %indicating reusability of the adsorbent. Analysis of adsorbent sustainability revealed that the synthesis was eco-friendly as indicated by low value of E-factor of 0.32.

Utilizing Bentonite as a Natural Material to Enhance the Quality of Community Water Resources in the Urban Area

In this study, the researchers investigated the state of water sources and the potential of bentonite as a water treatment agent. The study encompassed measurements of key water quality parameters for river and well water sources, including pH, TDS, conductivity, and salinity. The findings revealed that while pH levels were generally within the clean water standards, TDS values exceeded the threshold, particularly in river water samples. This suggests contamination due to urban activities and rising sea levels. Furthermore, the study explored using both activated and non-activated bentonite as an adsorption agent to remove contaminants from water sources. The results indicated that bentonite effectively increased pH levels, especially in well water samples, and significantly reduced TDS, conductivity, and salinity values, with non-activated bentonite being a preferred option for river water treatment and activated bentonite for well water treatment. These findings emphasize the potential of bentonite as a valuable water treatment solution. The specific characteristics of the water source should guide the choice between activated and non-activated bentonite. This tailored approach can lead to more effective and sustainable water treatment, contributing to improved water quality and availability for the community in the coastal region.

Sulfur dots corrosion inhibitors with superior antibacterial and fluorescent properties

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.

Optimization of the Methods to Develop Stable Polymer Gels for Water Management in Medium- and Ultra-High-Salinity Reservoirs.

Polymer gels suffer from a serious syneresis issue when exposed to high-temperature and high-salinity (HTHS) conditions, which limits their use as water-treatment agents in this type of reservoir. In this paper, the effects of the polymer type/concentration, deoxidizers, and stabilizers on the long-term stability of polymer gels were systematically studied; thus, the methods to develop stable polymer gels for two typical levels of salinity were optimized. The results show the following: (1) For a medium-salinity condition (TDS: 33,645.0 mg/L) at 125 °C, conventional HPAM gels completely dehydrate within only 1 day, and the addition of a deoxidizer hardly improved their stability. Some special polymers, e.g., AP-P5, MKY, and CPAM, are able to form stable gels if a high concentration of 0.8% is used; the syneresis rate of these gels is about 10% after 30 days. However, the addition of the complexant sodium oxalate significantly improves the stability of gels formed by all five of these different polymers, which behave with a 0% syneresis rate after 30 days pass. Complexants are the most economical and feasible agents to develop stable gels in medium-salinity water. (2) Gels enhanced using the methods above all become unstable in a more challenging ultra-high-saline condition (TDS: 225,068.0 mg/L). In this case, special calcium- and magnesium-resistant polymers are required to prepare stable gels, which show 0% syneresis rates after 30 days, have relatively low strengths, but do produce a good plugging effect in high-permeability cores.

Green mediated sol-gel synthesis of copper oxide nanoparticle: An efficient candidate for waste water treatment and antibacterial agent

Green mediated sol-gel synthesis of copper oxide nanoparticle: An efficient candidate for waste water treatment and antibacterial agent

Exploring the potential of metal and metal oxide nanomaterials for sustainable water and wastewater treatment: A review of their antimicrobial properties

Metallic nanoparticles (NPs) are of particular interest as antimicrobial agents in water and wastewater treatment due to their broad suppressive range against bacteria, viruses, and fungi commonly found in these environments. This review explores the potential of different types of metallic NPs, including zinc oxide, gold, copper oxide, and titanium oxide, for use as effective antimicrobial agents in water and wastewater treatment. This is due to the fact that metallic NPs possess a broad suppressive range against bacteria, viruses, as well as fungus. In addition to that, NPs are becoming an increasingly popular alternative to antibiotics for treating bacterial infections. Despite the fact that most research has been focused on silver NPs because of the antibacterial qualities that are known to be associated with them, curiosity about other metallic NPs as potential antimicrobial agents has been growing. Zinc oxide, gold, copper oxide, and titanium oxide NPs are included in this category since it has been demonstrated that these elements have antibacterial properties. Inducing oxidative stress, damage to the cellular membranes, and breakdowns throughout the protein and DNA chains are some of the ways that metallic NPs can have an influence on microbial cells. The purpose of this review was to engage in an in-depth conversation about the current state of the art regarding the utilization of the most important categories of metallic NPs that are used as antimicrobial agents. Several approaches for the synthesis of metal-based NPs were reviewed, including physical and chemical methods as well as “green synthesis” approaches, which are synthesis procedures that do not involve the employment of any chemical agents. Moreover, additional pharmacokinetics, physicochemical properties, and the toxicological hazard associated with the application of silver NPs as antimicrobial agents were discussed.

Inorganic phosphate regulated high luminescence NaYF4:Yb3+, Er3+ as an iron ion fluorescent nanoprobe

The iron ion in industrial circulating cooling water is an important indicator for early warning of equipment corrosion and control level. It is interesting to construct an upconversion luminescence iron ion nanoprobe with a common inorganic phosphate water treatment agent. Herein, inorganic phosphate sodium hexametaphosphate (SHMP) was used to regulate the morphology and functionalization of NaYF4:Yb3+, Er3+ upconversion luminescent nanoprobe (UCNPs) and applied to fluorometric detection of trace Fe(III) in water based on the fluorescence quenching which is caused by the selective coordination between hexametaphosphate on the surface of UCNPs and Fe(III). The structure, morphology, and luminous intensity of UCNPs were regulated by disodium hydrogen phosphate (ADSP), sodium tripolyphosphate (STPP) and sodium hexametaphosphate(SHMP). The UCNPs functionalized with SHMP has high sensitivity and selectivity for Fe(III) detection. The linear range and detection limit are 1.0–50 μM and 0.2 μM, respectively. The method has satisfactory results for the detection of trace Fe(III) in industrial circulating cooling water.

Degradation of ammonia nitrogen by an economic combined hydrodynamic cavitation method.

Hydrodynamic cavitation (HC) was a kind of advanced oxidation mode. There were defects in the common HC devices, such as high energy consumption, low efficiency, and easy plugging. In order to effectively utilize HC, it was urgent to research new HC devices and used them together with other traditional water treatment methods. Ozone was widely used as a water treatment agent that does not produce harmful by-products. Sodium hypochlorite (NaClO) was efficient and cheap, but too much chlorine will be harmful to water. The combination of ozone and NaClO with the HC device of propeller orifice plate can improve the dissolution and utilization rate of ozone in wastewater, reduce the use of NaClO, and avoid the generation of residual chlorine. The degradation rate reached 99.9% when the mole ratio γ of NaClO to ammonia nitrogen (NH3-N) was 1.5 and the residual chlorine was near zero. As for the degradation rate of NH3-N or COD of actual river water and real wastewater after biological treatment, the ideal mole ratio γ was also 1.5 and the ideal O3 flow rates were 1.0 L/min. The combined method has been preliminarily applied to actual water treatment and was expected to be used in more and more scenarios.

Preparation and Characterization of di- and Tricarboxylic Acids-Modified Arabinogalactan Plasticized Composite Films.

To ensure the high quality of water, it is necessary to remove toxic pollutants. At present, purification of water is implemented using various sorbents. The efficient sorption materials are modified polysaccharides. In this study, we report on a new environmentally friendly method for modifying larch hemicellulose-arabinogalactan (AG)-with polybasic carboxylic acids (citric, succinic, oxalic, and adipic) to obtain composite materials. The synthesized AG derivatives have been explored by a complex of physicochemical methods, including gel permeation chromatography (GPC), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffractometry (XRD), scanning electron microscopy (SEM), and sorption capacity investigations. It is shown that the heat treatment results in the formation of additional inter- and intramolecular bonds between carboxylic acids and polysaccharide molecules. The formation of ester bonds has been confirmed by the appearance of absorption bands in the IR spectra in the range of 1750-1690 cm-1. It has been found, using the TGA study, that the most thermally stable (up to 190 °C) sample is arabinogalactan oxalate obtained under heat treatment. The SEM study of the synthesized AG films has shown that the modified samples have the homogeneous film surface ensured by cross-linking. It has been established, when studying the sorption properties of the AG derivatives, that AG succinate (82.52%) obtained by lyophilization has the highest sorption capacity, due to the developed mesoporous surface, which, in turn, makes the synthesized films promising eco-friendly materials for use as drug carriers, sorbents, and water treatment agents.

Potential use of Plant Extract for Water Purification: A Review

Lack of treated water is one of the biggest problems encountered by humans. Microbial contamination is a major factor of water purity where enteric pathogens are typically responsible for water borne diseases. Research studies on the purification of water have been focused mainly on water purification systems using aluminium sulphate and chlorine which are expensive. Due to high cost of water treatment and rapid global spread of resistant microbes, there is the need for the discovery of new antimicrobial and water purification agents. The investigations into the possible usage of plant materials for water treatment is becoming a major focus. Many plants have been used to treat water due to their antimicrobial and purification properties. A number of effective coagulants and disinfectants have been identified of plant origin. Plants are rich in phytochemicals such as phenols, quinones, flavonols, tannins, coumarins and alkaloids which are responsible for the antimicrobial and water purification activities. This review discussed the potential application of indigenous plants to potabilisation. it was concluded that plant species have the potential to serve as water treatment agent. Keywords: Potabilisation; Plant extracts; Phytochemicals; Microbial contamination; Coagulants

Phycoremediation: Algae as an Effective Agent for Sustainable Remediation and Waste Water Treatment

Phycoremediation: Algae as an Effective Agent for Sustainable Remediation and Waste Water Treatment

Magnetic polyacrylonitrile/ZIF-8/Fe3O4 nanocomposite bead as an efficient iodine adsorbent and antibacterial agent

The efficient adsorption of radioactive iodine (129I and 131I) as nuclear waste is of great importance. Polymer nanocomposites consist of metal–organic frameworks (MOFs) developing for various pollutions sorption and separation have attracted much attention. This study reports the fabrication of magnetic polyacrylonitrile (PAN)/zeolitic imidazolate frameworks (ZIF-8) nanocomposites, PAN/ZIF-8(x%)/Fe3O4, x = 30 and 50, as iodine capture adsorbents. The PAN/ZIF-8(x%)/Fe3O4 nanocomposite beads were fabricated via the phase inversion method, and their potential for iodine capture and separation in solution and vapor was investigated through UV–vis and weighing methods, respectively. Also, antibacterial activity of the as-prepared beads was assessed against E. coil and S. aureus. The as-fabricated compounds were studied by various techniques such as Fourier-transform infrared, X-ray diffraction, scanning electron microscope, energy-dispersive X-ray spectroscopy mapping, transmission electron microscope, N2 adsorption isotherm, and vibrating sample magnetometer. The iodine capture results showed that the efficiency of nanocomposites is remarkably higher than the pure PAN beads. Additionally, the as-prepared nanocomposite adsorbents displayed higher capture capacities for iodine vapor (1524–4345 mg·g−1) than iodine solution (187–295 mg·g−1). The as-obtained magnetic nanocomposites can be successfully separated from polluted media by simple filtration or an external magnet, regenerated through washing with ethanol, and reused. Fast capturing, high sorption capacity, rapid separation, and good reusability make the PAN/ZIF-8(x%)/Fe3O4 nanocomposites highly effective adsorbents for the separation of iodine from wastewater. Additionally, PAN/ZIF-8(50%)/Fe3O4 bead can be considered as a potential new antibacterial agent for water and wastewater treatment.

Eco-Friendly and Facile Integrated Intumescent Polyelectrolyte Complex Coating with Universal Flame Retardancy and Smoke Suppression for Cotton and its Blending Fabrics

Cotton and its blended fabrics are widely used textile materials in daily life; however, their high flammability brings serious fire hazards. It remains a huge challenge to endow cotton and its blended fabrics through simple and universal technology. In this work, a novel water-based polyelectrolyte complex (PEC) coating was developed from chitosan and a water treatment agent (amino trimethylphosphonic acid). By controlling the degree of ion pair aggregation through pH adjustment, the intumescent and stable PEC coating can be constructed quickly via facile blading coating and curing processes. High transparency allows for the deposition of the coating with little effect on the original pattern of the coated fabric. Additionally, when the coated fabrics were exposed to flame, the PEC coating underwent a quick self-char-forming reaction in advance and formed a protective char layer covered on the fibers. Thus, the PEC coating with low adding-on (11.5–21.5 wt %) shows universally high flame retardancy for cotton, polyester/cotton blends, and polyester/poly(vinyl alcohol)/cotton blends. The coated fabrics show excellent extinguishing performances, high limiting oxygen index values of 27.5%–28.5%, and total release smoke inhibition of 42%. This work provides a promising universal technology for manufacturing fire-safety cotton and its blends in a simple and eco-friendly way.