Water Solution Research Articles

End-user participation in drinking water management through Awareness, Education, and Resources: tools for Water Partnerships

ABSTRACT The long-term success of safely managed drinking water systems requires participation from many stakeholders, especially the water users, but also community leaders, technical experts, health practitioners, teachers, NGOs, and others. However, people may need to be empowered before they can be confident or able to contribute to meaningful decision making or governance roles in Water Partnerships. Discussions with water leaders from nine organizations on four continents revealed surprisingly a similar three-step approach to empowering end-user participation in water management. The first step is creating the Awareness of local water challenges and their impact on health. The second step is Education about the options for safe water. Together, Awareness + Education lead to people understanding their challenges and being able to devise a locally appropriate solution. The third step is Resources for water action. Through Awareness, Education, and Resources, water stakeholders including households can be empowered to participate in safely managing drinking water solutions.

Advancements in Hydroponic Systems: A Comprehensive Review

Hydroponics, the practice of growing plants without soil using mineral nutrient solutions in water, represents a significant shift in agricultural methodologies. Modern hydroponic systems have evolved substantially since the early 20th century, with advancements in system design, automation, nutrient management, and environmental control enhancing efficiency, scalability, and applicability. This review examines recent innovations that have addressed traditional challenges and created new opportunities for hydroponic cultivation. Hydroponics offers advantages over traditional soil-based agriculture, including precise nutrient control, reduced water usage, and the elimination of soil-borne diseases and pests. These benefits are critical in addressing modern agricultural challenges such as soil degradation, water scarcity, and the need for increased food production for a growing global population. Hydroponic systems can be implemented in diverse environments, making them adaptable solutions for enhancing food security and sustainability. Key developments in various hydroponic systems are highlighted, including the Nutrient Film Technique (NFT), Deep Water Culture (DWC), Ebb and Flow, Aeroponics, Wick Systems, and Drip Systems. Innovations in these systems focus on optimizing nutrient delivery, oxygenation, and integrating sensors for precise control, improving overall performance and yield. Technological advancements, such as automation and control systems, sensors, and monitoring technologies, have revolutionized hydroponic farming by enabling real-time data collection and environmental management. The integration of the Internet of Things (IoT) and smart farming practices, combined with data analytics and machine learning, has further optimized system performance and decision-making. LED lighting and vertical farming techniques have maximized space utilization and improved crop yields, particularly in urban environments. Advances in nutrient solutions, disease management, and water quality have optimized plant health and resource efficiency. Economic and environmental considerations, including cost-benefit analyses and comparisons with traditional agriculture, highlight the potential for hydroponics to offer better returns on investment and reduce environmental impact. Despite the significant progress, challenges such as high initial setup costs and technical complexities remain. Future research opportunities and interdisciplinary collaborations are essential to address these challenges and drive further innovation in hydroponic farming.

Impact of Land Use Conversion on Soil Structure and Hydropedological Functions in an Arid Region

ABSTRACTLand use conversion critically affects soil structure and associated functions. This study investigated variations in soil structure and hydropedological characteristics across different land use types, that is, uncultivated, cultivated, and abandoned land under an arid condition. Water‐stable aggregates in the uncultivated land were 15.4%–37.1% of those in the cultivated and abandoned lands at depths of 0–60 cm. Reclamation of the uncultivated land enhanced soil aggregate stability, while prolonged tillage led to the loss of binding organic matter, breakdown of large aggregates and decrease in aggregate stability. The mean weight diameter of aggregates at 0–40 cm depth in the cultivated land was 39.0% lower than in the abandoned land. The volume fraction of micropores (< 100 μm) in the cultivated soils was 3.7%–39.7% of that in the uncultivated soils, whereas macropores (> 1000 μm) was 1.4–1.8 times greater. Following the abandonment, soil pore diversity recovered and a hierarchical structure developed. In the abandoned land, the volume fraction of micropores (< 100 μm) was 2.4–18.9 times that of the cultivated lands, while macropores (> 1000 μm) constituted 81.4%–93.9% of those in the cultivated lands. The permeability and longitudinal dispersivity of soils in the cultivated land were significantly lower than in the uncultivated and abandoned lands, particularly at deeper soil layers. The increase in large pores in the abandoned land, important for water movement and solute transport, resulted in an order‐of‐magnitude rise in both permeability and longitudinal dispersivity compared with the cultivated lands. Overall, the abandoned land showed potential for rehabilitation from the perspectives of soil aggregates and pore structure. The findings may provide reference for land reclamation and management in arid regions.

Origin of Intercrystalline Brine Formation in the Balun Mahai Basin, Qaidam: Constraints from Geochemistry and H-O-Sr Isotopes

The Balun Mahai Basin (BLMH), located in the northern Qaidam Basin (QB), is endowed with substantial brine resources; however, the genetic mechanisms and potential of these brine resources remain inadequately understood. This study investigated the intercrystalline brine (inter-brine) in BLMH, performing a comprehensive geochemical analysis of elemental compositions and H-O-Sr isotopes. It evaluated the water source, solute origin, evolutionary process, and genetic model associated with this brine. Moreover, a mass balance equation based on the 87Sr/86Sr isotopic ratio was developed to quantitatively evaluate the contributions of Ca-Cl water and river water to the inter-brine in the study area. The results suggest that the hydrochemical type of inter-brine in the north part of BLMH is Cl-SO4-type and in the south part is Ca-Cl-type. The solutes in brine are mainly derived from the dissolution of minerals such as halite, sylvite, and gypsum. The hydrochemical process of brine is controlled by evaporation concentration, water–rock interaction, and ion exchange interaction. Hydrogen and oxygen isotopes suggest that the inter-brine originates from atmospheric precipitation or ice melt water and has experienced intense evaporation concentration and water–rock interaction. The strontium isotopes suggest that the inter-brine was affected by the recharge and mixing of Ca-Cl water and river water, which controlled the spatial distribution and formation of brine hydrochemical types. The analysis of ionic ratios suggest that the inter-brine is derived from salt dissolution and filtration, characterized by poor sealing and short sealing time in the salt-bearing formation. The differences in hydrochemical types and spatial distribution between the north and the south are fundamentally related to the replenishment and mixing of these two sources, which can be summarized as mixed origin model of “dissolution and filtration replenishment + deep replenishment” in BLMH.

A Review on Nanofluids: Preparation, Stability Mechanisms, and Applications of Ethylene Glycol – Water Based Nanofluids Dispersed with Multi Walled Carbon Nanotubes

The current study examines the thermal conductivity and dynamic viscosity of ethylene glycol– water solutions comprising oxidized multiwalled carbon nanotubes. Nanofluids, the fluid suspensions of nanomaterials, have shown many interesting properties, and the distinctive features offer unprecedented potential for many applications. This paper summarizes the recent progress on the study of nanofluids, such as the preparation methods, the evaluation methods for the stability of nanofluids, and the ways to enhance the stability for nanofluids, the stability mechanisms of nanofluids, and presents the broad range of current and future applications in various fields including energy and mechanical and biomedical fields. At last, the paper identifies the opportunities for future research.

Synthesis of bagasse-derived magnetic biochar for the removal of fluoride from water solution

ABSTRACT Fluoride levels in drinking water pose a significant environmental threat, and adsorption is a common technique. However, many adsorbent materials have drawbacks such as poor adsorption capabilities, extended contact times, high pH levels, and large dosages. A biochar-based magnetic composite adsorbent has been developed for water defluoridation using a chemical co-precipitation process to immobilize iron particles on the biochar surface. X-ray diffraction analysis, Fourier transformed infrared spectroscopy, Brunauer–Emmett–Teller, and scanning electron microscopy were used to analyse the composite. The central composite design was used to design laboratory tests, which included four input variables: solution pH, dosage, contact time, and initial concentration. The adsorbent dosage was 5.92 g/L, the aqueous pH was 5.79, the contact time was 66.48 min, and the initial fluoride concentration was 12.38 mg/L. The removal efficiency was predicted to be 98.61%, with a 98.55% removal efficiency at optimum conditions. The study concluded that the composite adsorbent can be a reliable and sustainable solution for fluoride removal from water.

Influence of symmetry breaking on the absorption spectrum of crystal violet: from isolated cations at 5 K to room temperature solutions.

We report the resolution of a long-standing puzzle in molecular spectroscopy: the origin of the shoulder in the room temperature solution absorption spectrum of crystal violet (CV) - an archetypal cationic triphenylmethane dye. This was achieved by comparing experimental and theoretical results for CV in solution at room temperature and as an isolated cation in gas-phase at 5 K. The two lowest energy electronically excited states involved in the visible region absorption are degenerate and coupled via a Jahn-Teller (JT) mechanism involving phenyl torsions, making CV particularly sensitive to environmental perturbations. The shoulder is absent in the low-temperature isolated cation spectrum, and vibronic simulations based on time dependent density functional theory (TD-DFT) indicate negligible JT effects under these conditions. Combining vibronic simulations with molecular dynamics, demonstrates that in water and toluene solution at room temperature the shoulder arises mainly from an intermolecular, Jahn-Teller-like symmetry-breaking effect induced by the fluctuating electrostatic potential of the disordered solvent environment, rather than from molecular distortions.

DRILLING MUD THINNER BASED ON TECHNICAL LIGNOSULFONATES FROM WASTE OF CATALYST PRODUCTION

The article presents the results of research on obtaining liquid thinners for drilling muds from waste generated at one of the technological stages in the production of sulfocationic catalysts from technical lignosulfonates.During the production of heterogeneous sulfo-cationic sorbents and catalysts from technical lignosulfonates, acidic waters containing low-molecular-weight fractions of lignosulfonates, residues of hemicellulose hydrolysis products, water-soluble, and extractive substances are generated at the stage of washing off the residual acid. One of the ways to utilize the generated waste could be its further processing into new reagents. Therefore, the aim of this work was to develop a formulation of a thinner based on the generated waste and study its effectiveness in typical drilling muds. A dry industrially produced lignosulfonate was used as a reference reagent.The possibilities of using the resulting liquid waste to obtain highly effective thinners for drilling muds based on lignosulfonates are shown. It is revealed that the resulting reagent reduces the rheological parameters of the drilling mud, is comparable in effectiveness to dry industrially produced lignosulfonate (0.5 % by weight and 1 % by weight), and is technologically easy to use. In fresh water solutions, the modified form of the reagent with the addition of oxyethylidenediphosphonic acid is more effective, while in mineralized solutions the unmodified form is more effective.

Amelioration of fructose-induced hepatic lipid accumulation by vitamin D3 supplementation and high-intensity interval training in male Sprague‒Dawley rats

BackgroundIntrahepatic lipid accumulation (IHL), a hallmark of metabolic disorders, is closely associated with de novo lipogenesis (DNL). Notably, fructose feeding increased the DNL. Lifestyle modifications resulting from dietary changes and increased physical activity/exercise can decrease the IHL content. We examined the effects of vitamin D3 supplementation (VDS), high-intensity interval training (HIIT), and their combination on the transcription factors and enzymes of the DNL pathway in male Sprague‒Dawley rats fed a high-fructose diet (HFrD).MethodsForty male rats were assigned to 5 groups (n = 8): CS (the control group had a standard diet); CF (the control group had HFrD (10% (w/v) fructose solution in tap water)); and FT (HFrD + HIIT: 10 bouts of 4 min of high-intensity running, corresponding to 85–90% of the maximal speed with 2 min active rest periods of 50% maximal speed, 5 days per week); FD (HFrD + intervention of intraperitoneal injection of 10000 IU/kg/week VDS); FTD (HFrD + HIIT + VDS) that were maintained for 12 weeks. ELISA, the GOD-POD assay, folch, western blotting, and oil red O staining were used to determine insulin, fasting blood glucose (FBG), hepatic triglyceride (TG) and cholesterol levels; SREBP1c, ChREBP-β, ACC1, FASN, p-ACC1, AMPK, p-AMPK, and PKA protein expression; and IHL content, respectively.ResultsBoth HIIT and VDS led to significant increases in the levels of PKA, AMPK, p-AMPK, and p-ACC1, as well as significant decreases in the levels of SREBP1c, ChREBP-β, ACC1, FASN, insulin, FBG, liver TG, liver cholesterol, and IHL. HIIT exhibited superior efficacy over VDS in reducing ChREBP-β, ACC1, insulin, FBG, liver TG and cholesterol, as well as increasing p-ACC1 and PKA. Notably, the combined intervention of HIIT and VDS yielded the most substantial improvements across all the parameters.ConclusionsHFrD causes IHL accumulation and the onset of diabetes, whereas VDS and HIIT, along with their combined effects, prevent the consequences of HFrD.

Choice of an environmentally friendly method of producing cellulose from flax biomass (<i>Linum usitatissimum linaceae</i>) grown in different regions of the Volga region

The experimental assessment of prospects of receiving cellulose material on the basis of use of vegetable raw materials – straw of a flax-dolgunetc is carried out. Results of researches showed a possibility of application for extraction of cellulose of the water solutions containing hydrogen peroxide, hydroxide and sodium bisulfite in the conditions of high-temperature influence within 2 hours with receiving the technical cellulose suitable for production of cardboard and packaging materials. For purification of technical cellulose, it was carried out additional processing by solution of hydrogen peroxide and acetic acid in similar parametrical conditions that allowed to receive a target product with high extent of maintenance of the main substance, at insignificant amount of the accompanying impurity. The presented results show a possibility of the solution of questions of environmental safety at the organization of process of receiving cellulose on the basis of renewable vegetable raw materials with use of the chemical reagents which are not containing compounds of sulfur.

Synthesis and application of pH- and thermoresponsive PVCL-PVA hydrogel/MWCNTs nanocomposite for efficient removal of methylene blue from water solutions

Synthesis and application of pH- and thermoresponsive PVCL-PVA hydrogel/MWCNTs nanocomposite for efficient removal of methylene blue from water solutions

A Universal Approach for High-Yield Synthesis of Single-Crystalline Ordered Macro-Microporous Metal-Organic Frameworks.

Despite the excellent properties of single-crystalline ordered macro-microporous MOFs (SOM-MOFs) compared to conventional MOFs, their further development has been hindered by the lack of versatile and high-yielding preparation protocols. This study introduces an innovative universal fabrication method that can easily solve the two major challenges of precursor stabilization and crystallization modulation, enabling the efficient synthesis of various SOM-MOFs with high yields. Notably, our approach has successfully yielded SOM-MIL-88A, a novel MOF showcasing exceptional stability in both water and acidic solutions, a remarkable achievement unprecedented in prior SOM-MOF research. SOM-MIL-88A has demonstrated exponentially improved performance over conventional MIL-88A in adsorption, catalysis, immobilized enzymes, and composite biosensing. Furthermore, our versatile protocol has been successfully applied to synthesize SOM-HKUST-1 and SOM-ZIF-8, resulting in significantly improved yields (increase by about 10-fold and 2-fold, respectively, compared to the previously reported protocol). This groundbreaking achievement marks a pivotal advancement in the preparation of diverse SOM-MOFs with tailored properties, presenting exciting prospects for future research on MOFs.

Sustained Regeneration of Hydrogen Peroxide at the Water-Gas Interface of Electrogenerated Microbubbles on an Electrode Surface.

Microbubbles, inside-out microdroplets, act as extraordinary microreactors to facilitate thermodynamically unfavorable reactions in bulk solutions of water. We explored the formation of hydrogen peroxide (H2O2) and its sustained regeneration at the interface of water-gas microbubbles. For this purpose, the chemiluminescence of luminol was recorded by a digital camera to map the intensity of blue light emission over the time of about 20 min. The formation and regeneration of hydrogen peroxide were also monitored by fluorescence microscopic imaging of a hydrogen peroxide probe. The microscopic images consistently show a stable glow around the microbubbles over time during which the formed hydrogen peroxide diffuses into the bulk solution. This observation confirms that the concentration of H2O2 at the interface is 30 times higher than that in the water solution bulk after several minutes, which can be attributed to its regeneration at the water-gas interface. These findings increase our understanding of why the chemistries of gas microbubbles in water and water microdroplets surrounded by gas are so distinct from those of bulk-phase water.

An MIP-Based PFAS Sensor Exploiting Nanolayers on Plastic Optical Fibers for Ultra-Wide and Ultra-Low Detection Ranges-A Case Study of PFAS Detection in River Water.

In this work, a novel optical-chemical sensor for the detection of per- and polyfluorinated substances (PFASs) in a real scenario is presented. The proposed sensing approach exploits the multimode characteristics of plastic optical fibers (POFs) to achieve unconventional sensors via surface plasmon resonance (SPR) phenomena. The sensor is realized by the coupling of an SPR-POF platform with a novel chemical chip based on different polymeric nanolayers over the core of a D-shaped POF, one made up of an optical adhesive and one of a molecularly imprinted polymer (MIP) for PFAS. The chemical chip is used to launch the light into the SPR D-shaped POF platform, so the interaction between the analyte and the MIP's sites can be used to modulate the propagated light in the POFs and the SPR phenomena. Selectivity tests and dose-response curves by standard PFOA water solutions were carried out to characterize the detection range sensor response, obtaining a wide PFAS response range, from 1 ppt to 1000 ppt. Then, tests performed on river water samples collected from the Bormida river paved the way for the applicability of the proposed approach to a real scenario.

Activity coefficients of 3-amino-1-propanol and 2-amino-1-propanol in aqueous solutions from surface tension data

Surface tension of 3-amino-1-propanol and (RS)-2-Amino-1-propanol in aqueous solution were measured in the temperature range from 293.15 to 308.15 K at intervals of 5 K over the whole concentration range. The concentration dependence of surface tension for both amino alcohols aqueous solution shows a similar behavior to that observed for other polar solutes in water. The surface tension data of 3-amino-1-propanol and 2-amino-1-propanol at the selected temperatures were accurately described using the integral Gibbs adsorption equation, the virial equation, and the Langmuir-Gibbs equation of state. The activity coefficients γ for both solutes were determined using the virial equation and found to be unitary within the experimental uncertainty, which was confirmed by the accurate representation of the experimental data by the Langmuir Gibbs Equation of State (LGSEOS). The standard adsorption energy calculated for both solutes from the fitting parameters of LGSEOS to the experimental data indicates that (RS)-2-amino-1-propanol has a higher hydrophobic character and a greater tendency to migrate to the surface than 3-amino-1-propanol as shown by the more negative ΔGads0 values for this solute than for 3-amino-1-propanol.

Hydrodynamic and Temperature Profile Analysis in a Gas-Solid Fluidized Bed with Liquid Atomization to Convert Fructose to Value-Added Chemicals

Carbohydrates specified C6 sugars dehydrate to produce platform chemicals like 5-hydroxymethyl furfural and furfural that further oxidize to chemicals 2,5-diformyl furan and 2,5-furan dicarboxylic acid. Here we propose a gas-phase in which a two-fluid nozzle atomizes a 0:1 ▪ fructose in water solution into a fluidized bed of Mo–V–▪/▪. However, the imperfect interaction between droplet and catalyst increases the agglomeration, which destroys the heat transfer efficiency and hydrodynamic stability. We evaluated the temperature and gas residence time distribution in catalytic bed to improve reaction and process performance by modifying the bed temperature, bed height, and gas velocity. A high mass of catalyst (>▪) degrades fructose and reduces the selectivity. At ▪ temperature distributes homogeneously within bed and with time on process it shifts toward higher values. Velocity in the range of ▪ to ▪ yield product with the highest selectivity (16%). These results demonstrate the potential of optimizing gas-phase catalytic processes to improve the selective production of platform chemicals from carbohydrates, supporting more sustainable chemical manufacturing.

Mechanistic Simulation of Salt‐Affected Soil‐Plant‐Atmosphere Continuum Dynamics in Seasonally Frozen Regions

AbstractThe salt‐affected Soil‐Plant‐Atmosphere Continuum (SPAC) is a dynamic, interactive system that is particularly complex in seasonally frozen regions where salt transport, precipitation‐dissolution, and soil freeze‐thaw processes play crucial, interrelated roles. Understanding these coupled processes and representing them with mathematical models is critical for effective management of SPAC systems. This study presents a new mechanistic approach and an improved model that integrates a chemical equilibrium module within a mechanistic‐based transport computational module (modified SHAW model). The chemical equilibrium module determines salt precipitation‐dissolution using thermodynamic theory and explains the effects of efflorescence and subflorescence on system dynamics. The model enables simultaneous solutions for heat, water, and salt transport with chemical equilibrium throughout non‐freezing and freezing seasons, as well as plant growth dynamics. Assessment of the model using laboratory experiments and field studies showed good performance, with coefficient of determination values exceeding 0.65 for simulated and measured evaporation rate, leaf area index, soil water content, salt content, and temperature. Furthermore, a comparison between simulation results considering and neglecting the impact of salt precipitation‐dissolution highlights potential inaccuracies in soil heat‐water‐salt dynamics and plant water use resulting from the omission of this process in mechanistic models.

Evaluation of H2O2, H2, and bubble temperature in the sonolysis of water and aqueous t-butanol solution under Ar: Effects of solution temperatures and inorganic additives of NaCl and KI

The yields of H2O2 and H2 formed in the sonolysis of aqueous solution under noble gas are representative indexes for understanding the chemical effects of ultrasonic cavitation bubbles. In this study, the yields of H2O2 and H2 formed under Ar were evaluated as a function of the concentration of NaCl or KI. When these yields were analyzed by using a normalization technique, it was confirmed that the yields of H2 were more clearly related to Ar solubility than those of H2O2, suggesting that H2 is a more real probe to understand the chemical effects of cavitation bubbles in water. The effects of NaCl on sonochemical formation of oxidants were also compared with those of KI. When aqueous t-butanol solution was sonicated, the yields of H2 and the maximum temperature attained in a collapsing bubble (bubble temperature) decreased with increasing solution temperature and salt concentration, suggesting that these parameters affected the quantity related to the number (and/or size) of active bubbles as well as the quality related to the bubble temperatures.

Amelioration of extremely acidic environment of soy protein amyloid fibrils to enhance gelation performance by dialysis strategy: Effects of pH and ions

The application of soy protein amyloid fibrils (SAFs) to food industrialization field has received focused attention because of their advantages such as ordered supramolecular structure and anti-proteolytic properties. However, the comparatively weak gelation properties of SAFs make it difficult to form self-supporting hydrogels, limiting its potential for future applications. Additionally, the extremely acidic environment (pH 2) of SAFs hinders their practical application in the food pH range (4-7). To address this issue, a dialysis strategy was utilized to enhance the gel structure of SAFs in this paper. The SAFs were dialyzed by deionized water and zinc ions solutions with four different pHs (2, 4, 7, and 9), and the impact of various dialysates on rheological properties, water distribution, and microstructure was investigated. The results demonstrated the method significantly improved gelation properties and modified the extremely acidic environment of SAFs. Various samples were continuously deacidified during dialysis in solutions of different pHs (4, 7, and 9), transforming from pH 2 to a higher pH value. Visual images exhibited that self-supporting hydrogels can be formed by SAFs just at a low concentration of 3% (wt). SAFs-Zn2+-9 hydrogel exhibited the highest storage modulus with a 500-fold compared to SAFs-2. Notably, the SAFs-H2O hydrogels were fabricated without any exogenous substances, in which the storage modulus of SAFs-H2O-9 increased by over 300 times. AFM images demonstrated that the shift from long rigid fibrils to short flexible fibrils induced tightly entanglement among fibrils, which improved gelation performance. Moreover, the transform in pH and the incorporation of ions caused the hydrogels to show dense network structure and strong water retention capacity. The ingenious insights were provided for improving the gelation performance of SAFs and modifying the polar acidic environment in the study, fully exploiting the potential of SAFs as edible ingredients for food applications.

Efficacy of different disinfecting methods for contact lenses against Acanthamoeba castellanii

PurposeTo analyze the efficacy of different disinfecting methods for contact lenses (CL) against Acanthamoeba castellanii (AC) using quantitative PCR (qPCR) based on RNA detection. MethodsThree CL materials: rigid gas permeable (RGP), hydrogel (Hy), and silicone hydrogel (SiHy), were contaminated with 1x105 amoebae/ml and incubated for 24 h at 30 °C. After contamination, pre-cleaning steps were performed before using four maintenance solutions based on hydrogen peroxide (HP), sodium hypochlorite (SH), povidone-iodine (PI), and a multipurpose solution (MS). The pre-cleaning steps involved using a cleaner (20 % isopropyl alcohol) and rinsing the CL. Disinfection systems 1 and 2 involved no cleaner and rinsed the CL with tap water or saline solution, respectively. Systems 3 and 4 included a cleaner and rinsed with tap water or saline, respectively. After cleaning, A. castellanii was extracted and stored for qPCR analysis, using Hsp70 and TPBF genes to detect RNA A. castellanii. Results were presented as the percentage of positives or negatives (presence or absence of amoebae), with a p-value < 0.05 considered statistically significant. ResultsDisinfection system 1 with MS resulted in 56 % positives for RGP lenses and 100 % positives for both hydrogel materials. When MS was combined with a cleaner, 12.5 % positives were found for SiHy and 100 % negatives for Hy and RGP lenses (p < 0.05). PI solution alone yielded 38 % and 12 % positives for hydrogel and silicone hydrogel lenses, respectively, but was 100 % effective when combined with a cleaner. HP and SH, whether combined with a cleaner or not, were effective against AC for all CL materials except HP without a cleaner for Hy lenses. ConclusionAll disinfection methods showed some efficacy against Acanthamoeba on any CL material. The most effective solutions were those based on hydrogen peroxide and sodium hypochlorite. Using a cleaner enhanced the final disinfecting efficacy, especially with the multipurpose solution.