Water Corrosion Research Articles

A Critical Review on Corrosion and Fouling of Water in Water Distribution Networks and Their Control

Corrosion and scaling are among the problems that may arise when storing water in tanks. Several factors affect the corrosion and scaling of water, which include pH, temperature, alkalinity, Ca2+ hardness, TDS, concentrations of Cl–, SO42–, CO32–, and HCO3–. Also, several indices can be measured using these properties such as the Langelier saturation index, Ryznar index, Aggressive index, Larson, Scold index, water quality index, and Puckorius index. These indicators determine the degree of corrosiveness and sedimentation of water. The purpose of this review article was to study the impact of various factors on the corrosiveness and sedimentation of water. To this end, different sources of water in different countries were studied and the impact of physical and chemical parameters on their corrosiveness was investigated. Also, the reaction mechanism of water corrosion inside the pipe was studied. Finally, practical and constructive suggestions were presented to solve the problems of corrosion and sedimentation of desalination water.

THE IMPORTANCE OF URINE RECOVERY FROM MUNICIPAL WASTEWATER

Urine contains a high concentration of nutrients that could increase water pollution and corrosion in the sewerage system. Along with the decrease in global phosphorus reserves, this condition may aggravate the worldwide population’s vulnerability in food security, drinking water, sanitation, and hygiene. This paper aims to gain more knowledge on the importance of urine recovery from municipal wastewater. The previous implementation of the urine separation system, the importance of urine diversion, the potential product, and technologies for urine recovery was briefly described. Overall, urine diversion is expected to address those environmental problems by reducing water pollution and organic loading in wastewater treatment plants, providing valuable nutrients for agricultural production, and lessening the economic cost of improper sanitation.

Simple and eco-friendly fabrication of highly tolerant chitosan/alginate@sepiolite hybrid films on nylon textile for oil/water separation in harsh conditions

Because of the need of achieving efficient separation to oil/water mixture, the construction of separation coating with good mechanical strength and chemical resistance are highly desired. Although many polysaccharide-based coating for oil/water separation have been prepared, the poor durability and the environmentally unfriendly preparation process greatly restrict their applications. Herein, sepiolite (SP) was introduced into chitosan/alginate (CS/AG) matrix to produce nacre-like composite films with superb robustness and stability via a simple and green layer-by-layer (LbL) self-assembly technique. After the composite films are fabricated on nylon textile (NT), the hydrophilicity and underwater superoleophobicity of the NT surface are significantly improved. The composite coating also reveals excellent oleophobic stability after being subjected to corrosive liquids immersion, high-temperature treatment, strong abrasion, and organic solvents immersion. Furthermore, the modified NT is able to separate oil/pure water, oil/cold corrosive water, and oil/hot corrosive water mixtures with high filtration efficiency (>98.3 %). Especially, the separation to oil/hot corrosive solution mixtures can be repeated at least 40 times without obvious decrease of separation efficiencies. This investigation offers a new and eco-friendly strategy to prepare SP coating-based membrane materials with good superhydrophilicity, mechanical property, and recyclability for oily wastewater purification.

Achieving CVD diamond films on Mo0.5(TiZrTaW)0.5 highly concentrated alloy for ultrastrong corrosion resistance

The diamond film offers strong corrosion resistance but remains largely a challenge to synthesize the continuous film with simultaneous high nucleation density and growth on practical alloys. Here, we report herein diamond films deposited on Mo0.5(TiZrTaW)0.5 highly concentrated alloy by chemical vapor deposition and the corrosion behaviors in 3.5 wt% NaCl and 1 M HCl solutions. The result shows that the diamond films are oriented from the mixed-carbides MC [011] (M = Mo, Ti, Ta and W) layer. The specimens with the continuous film exhibit ultrastrong corrosion resistance, which provides an insightful approach in the fields of water treatment and corrosion protection.

An Electrode‐Grounded Droplet‐Based Electricity Generator (EG‐DEG) for Liquid Motion Monitoring

AbstractTriboelectric nanogenerator (TENG) is a potential technology for harvesting water energy and serving as self‐powered sensors. Among the innovative designs of TENG, a droplet‐based electricity generator (DEG) has achieved high instantaneous power density under droplets impinging. However, the exposed top electrode is usually hydrophilic and subjected to water corrosion. This study reports an electrode‐grounded droplet‐based electricity generator (EG‐DEG) with graphene sheets embedded carbon (GSEC) electrode. Compared with traditional electrodes, the designed device with GSEC electrode exhibits great hydrophobicity, corrosion resistance under droplets impinging and better output performance. The working mechanism of the device is discussed in depth and the performance of EG‐DEG is systematically studied. To demonstrate the robust capability of EG‐DEG as self‐powered sensors, a three‐electrodes mode of EG‐DEG is developed to monitor droplet velocities on different triboelectric surfaces. Furthermore, the EG‐DEG can be assembled in the pipe to acquire the flow rate of fluid according to the frequency of the output signals. An intelligent system is further developed to display the flow rate of the fluid. Therefore, the EG‐DEG device also shows its great application prospects in particles detection and fluid analysis in the future.

Evidence for an effective defence against ocean acidification in the key bioindicator pteropod Limacina helicina

Abstract The pteropod Limacina helicina has become an important bioindicator species for the negative impacts of ocean acidification (OA) on marine ecosystems. However, pteropods diversified during earlier high CO2 periods in Earth history and currently inhabit regions that are naturally corrosive to their shells, suggesting that they possess mechanisms to survive unfavourable conditions. Recent work, which is still under considerable debate, has proposed that the periostracum, a thin organic coating on the outer shell, protects pteropods from shell dissolution. Here, we provide direct evidence that shows that damage to the L. helicina periostracum results in dissolution of the underlying shell when exposed to corrosive water for ∼8 d, while an intact periostracum protects the shell from dissolution under the same conditions. This important first line of defence suggests that pteropods are more resistant to OA-induced shell dissolution than is generally accepted.

Investigation into durability degradation and fracture of cable bolts through laboratorial tests and hydrogeochemical modelling in underground conditions

Premature failures of cable bolts caused by durability degradation in underground reinforcement systems have been more and more often observed. To identify various factors affecting the corrosion process, the corrosion processes were examined through laboratorial testing programs as well as hydrogeochemical modelling. Experiments were carried out in simulated underground conditions in “corrosion cells” containing stressed cable bolt specimens as well as groundwater, clay, coal or a combination of the materials. Water chemistry and corrosion pattern analysis of specimens in different testing conditions were conducted. Hydrogeochemical models were established and the formation of corrosion products, the change of ion concentration and factors related to corrosion rates were studied. The results showed the corrosion degree of specimens could be classified into three categories. The dissolved oxygen was the main factor affecting the general corrosion and stress level, pH and electrical conductivity were secondary factors. Erosive ions were main factors affecting localised corrosion which was mainly observed to form at high stress areas. A ‘staple’ like crack initiated at localised corrosion were observed which was identified as a potential site for stress corrosion cracking. The modelling results showed sulphide iron generated in presence of microorganisms which would also accelerate stress corrosion of specimens. The obtained results and proposed methodologies would establish quantifiable data to compare variable mine conditions and help understand the corrosion mechanisms in underground conditions.

Uniform Longitudinal Zinc Growth beyond Interface Guided by Anionic Covalent Organic Framework for Dendrite‐Free Aqueous Zinc Batteries

AbstractAqueous zinc (Zn) batteries hold considerable promise to address safety problems that frequently occur in electric vehicle cells or energy storage applications. However, Zn metal anode suffers seriously from dendrite, corrosion, and interface water decomposition in aqueous electrolytes, especially under large areal capacity or long charging duration. This is mainly because of the uneven longitudinal Zn growth induced by the anisotropic Zn2+ diffusion, which is usually neglected in a laboratory study with low areal capacity. Herein, we report an artificial interface of the anodic covalent organic framework (COF, which can be rapidly synthesized and facilely assembled with Zn anode in a large area) to guide the uniform longitudinal Zn growth for dendrite‐free Zn batteries. In‐situ optical microscope observes that compared with the bare Zn anode, COF interface can promote the formation of the smooth and dendrite‐free surface through spatial‐triggered uniform longitudinal Zn growth. Theoretical calculation uncovers that anodic COF with a negative charge at its N sites could attract Zn2+ to achieve uniform longitudinal Zn2+ diffusion. In addition, this COF interface with superior hydrophobicity could suppress water decomposition and Zn corrosion. Consequently, the COF‐functionalized Zn anode realizes a high coulombic efficiency under severe Zn plating/stripping conditions (10 mAh cm−2), contributing to a long Zn‐I2 full battery life of over 10000 cycles. This work highlights the high‐areal‐capacity Zn anode protection in external space beyond the interface.

On the application of liquid metal cooling for electronic switching devices

Increasingly smaller and lighter power electronics converters are needed for the advancement of electrified transport. The development of high heat flux heat sinks is imperative to maintain modern converters at an operable temperature. So far, liquid metal based heat sinks have not received as much attention as other solutions, yet they provide a multitude of benefits beyond their superior thermal conductivity. Their use with compact magnetohydrodynamic pumping systems, straight-forward incorporations of active cooling techniques, elimination of water corrosion issues in power converter systems using press-pack IGBT’s and a significant increase in thermal performance in conventional pin–fin structures are demonstrated in this paper. Some additional functionalities of liquid metal systems which could be explored in the future are also highlighted.

Biocorrosion of Carbon Steel under Controlled Laboratory Conditions

In the Iberian Pyritic Belt (SW Europe), Acid Mine Drainage (AMD) is the consequence of the interaction of physical-chemical and biological factors, where aerobic Fe and/or S oxidizing chemolithotrophic and anaerobic sulfate reducing bacteria play an essential role. As a result, the polluted waters are highly acidic (pH 2–3) and contain numerous dissolved or suspended metals, which gives them a powerful corrosive action on constructions related to mining activities with high economic losses. To verify the role of bacteria in the corrosion of carbon steel, a common material in buildings exposed to corrosion in acidic waters, several experiments have been carried out under controlled conditions using carbon steel bars and acidic water containing bacteria consortia from an AMD river of the Iberian Pyritic Belt. In all the experiments carried out, a remarkable oxidation of supplemented iron was observed in the presence of bacteria. Using carbon steel as the sole iron source, we observed a slight corrosion of the bars, but when culture media was supplemented with elemental sulfur, steel bars was severely damaged. Since the bacteria inoculum come from the surface water, well oxygenated, nutrient-poor river, the obtained results are discussed based on facultative metabolism of acidophilic chemolithotrophic bacteria.

Cold-end corrosion caused by hygroscopic ammonium chloride in thermal conversion of biomass and waste

Optimization of energy recovery and efficient use of the energy in flue gases is of high importance for the economy of power plants. The fuel quality and additives to mitigate corrosion may dramatically affect cold-end deposits and corrosion. Ammonium chloride may form in the cold-end of the boiler if the flue gases contain both HCl(g) and NH3(g). Ammonia may be present in the cold-end when using ammonium-based additives or operating the boiler at low load leading to an NH3(g) slip. Ammonium chloride is a hygroscopic salt, which can cause corrosion of pre-heaters and flue gas cleaning equipment NH3(g) and HCl(g) can also pass through filters and form NH4Cl(s) after the baghouse filters. In this work, the hygroscopic properties of NH4Cl were determined by measuring the conductivity of the salt during decrease of temperature at various water vapor concentrations (10–35 vol%). The corrosiveness of NH4Cl salt on carbon steel was studied at 25 vol% water vapor in the temperature range of 70–160 °C. The cross-sections were analyzed using SEM-EDX, and corrosion rates were determined from panorama SEM images by analyzing the material loss in about 50 000 points. The material loss was also determined gravimetrically after removing the corrosion products with citric acid. The work revealed that hygroscopic NH4Cl is highly corrosive on carbon steel when water is absorbed. Water uptake and corrosion occurred at relative humidities well below the deliquescence relative humidity and depended on the temperature. An empirical equation for water uptake by NH4Cl was determined for water vapor concentrations between 10 and 35 vol% H2O. As corrosion proceeded, chlorine was enriched close to the carbon steel surface due to the formation of iron chlorides. The results can be used to avoid conditions typical for NH4Cl deposit build-up and create strategies to prevent corrosion.

Thermos-physical properties and corrosion behaviors of monoclinic Gd4Al2O9 ceramic exposed to pressurized water at 360 °C

For assessing the performance of monoclinic Gd4Al2O9 ceramic as burnable poison absorber in the pressurized water reactor, the basic properties of the high-density Gd4Al2O9 ceramics prepared by solid state reaction are studied herein, including the thermos-physical and water corrosion properties. Furthermore, the water-corrosion mechanism of Gd4Al2O9 ceramics is also disclosed associated with the composition and morphology evolution.

Fluorine‐phosphate copolymerization waterborne acrylic resin coating with enhanced anticorrosive performance

AbstractThe modified waterborne acrylic resin was synthesized successfully by emulsion polymerization with octafluoropentyl methacrylate and phosphate functional monomer as monomers, showing an improved anti‐corrosion performance of the resin coating. The existence and general distribution of the elements of the modified monomer in the emulsion were explored, and the anti‐corrosion mechanism was disclosed. The results show that the modification of octafluoropentyl methacrylate and phosphate functional monomers improved the water resistance, corrosion resistance and thermal stability of acrylic resins. Compared with unmodified acrylic resin, the contact angle of the modified resin was increased from 74.23° to 83.51°, and the initial decomposition temperature was increased from 264 to 305 °C. At the same time, the corrosion voltage of the modified resin was increased, the corrosion current density was decreased, and the salt spray resistance was improved. This study provides a new way for the preparation of environmentally friendly, stable, and corrosion‐resistant waterborne acrylic resins.

Salt Water Corrosion Behaviour of Composite Coated Al-6061 Developed Through HVOF

Salt Water Corrosion Behaviour of Composite Coated Al-6061 Developed Through HVOF

Effect of the stearic acid modified metakaolin on sulfate resistance of mortar based on the experimental study and capillary theory analysis

In this study, a stearic acid modified metakaolin (MMK) was developed to improve the sulfate resistance of cement-based materials, which could effectively avoid the adverse effects of traditional hydrophobic modifier on the mechanical properties of cement mortar itself. Firstly, the effects of the stearic acid content and grinding time on the water contact angle of the MMK were studied, and the results showed that the MMK had the maximum water contact angle when the stearic acid content was 5% and the grinding time was 20 min. On this basis, abundant systematic tests were conducted to study the effects of the MMK mass fraction on water contact angle and water absorption of the mortar. Subsequently, the sulfate resistance of the mortar with MMK was examined under partial immersion, including the apparent morphology, linear expansion rate, relative dynamic elastic modulus, compressive strength and microstructure. Finally, a mathematic model considering water absorption and evaporation was developed, and the effects of the MMK on the corrosion height, capillary absorption and water evaporation of the specimen under partial immersion in sulfate solution were analyzed. The model analysis showed that the MMK could reduce the capillary water absorption height of the specimen under partial immersion in sulfate solution, and the mechanism of sulfate resistance for the mortar with the MMK was to reduce the amount of corrosive ions by reducing the capillary coefficient.

Study on nanocrystalline coating prepared by electro-spraying 316L metal wire and its corrosion performance

Abstract In this work, we study the corrosion performance of coatings prepared by electrical explosion spraying of metal wires. 316L metal wire with a diameter of 1.5 mm is used as spray material, and the coating is prepared on the 45# steel substrate by electrical explosion spraying. The oil–water corrosion experiment of the coating is carried out in a constant temperature water bath of 60°C for 168 h. The scanning electron microscopy and energy-dispersive spectroscopy results of the experimental samples have shown that some metal oxides are found inside the coating, most of which are distributed at the grain boundaries with a size range of 30–50 nm. The corrosion rate of the coating is measured by weight loss method with a corrosion rate of 0.079 mm/annum. XRD results show that the corrosion generates CaCO3, Fe3O4, and MgFe2O4. Coating corrosion is mainly caused by the formation of electrochemical corrosion between oxides and non-oxides in the coating, and pitting corrosion and intergranular corrosion in the presence of chloride ions.

The effect of sambiloto leaf (Andrographis paniculata Nees) extract inhibitor concentration on the corrosion rate of iron in the corrosive HCl medium and well water

Corrosion is a chemical reaction between metal and chemical substances in free air influenced by typographical conditions, climate, and humidity levels around the metal object. If left unchecked, it can cause damage to the metal infrastructure, material losses, and harm in terms of safety and security. Therefore, a way to inhibit corrosion is needed by creating an environmentally friendly inhibitor from natural materials. One of them is by utilizing Sambiloti leaf as a natural inhibitor. Sambiloto leaves contain tannins which can inhibit corrosion well. This study aimed to determine the efficiency of Sambiloto leaves ethanol extract in inhibiting the corrosion rate of metals in the corrosive medium of well water. HCl was soaked for seven days to determine the correlation between the corrosion rate and extract concentration in different corrosive media. Sambiloto leaves were extracted using the soxhletation method using 96% ethanol solution, then distilled to obtain a pure extract. Sambiloto leaf extract was then varied in concentration, namely 1%, 5%, 10%, and 15%. The corrosive medium is well water and HCl, and the metal material used is nails. The results showed that adding Sambiloto extract with a concentration of 15% in both corrosive mediums had the highest inhibitor efficiency values, namely 97.32% in the corrosive HCl medium and 69.3% in the corrosive well water medium. The results of the regression analysis showed that the addition of Sambiloto extract had a significant effect on the corrosion rate in well water media. In contrast, in the HCl medium, the addition of Sambiloto extract did not significantly affect the corrosion rate.

Impact of pipeline materials on water quality stability of desalinated seawater in the pipeline network

Desalinated seawater is usually weakly acidic, extremely low in hardness and alkalinity, has poor stability, and is highly corrosive.-Before water enters the municipal pipe network, its stability and safety must be guaranteed. We found that the pipe material has a big impact on the water quality of reverse osmosis (RO) desalinated seawater. Cement mortar lined ductile iron pipe (CMDIP) reduces water corrosion. Desalinated seawater requires regulation to ensure chemical stability. Disinfection should occur before transmission and distribution of post-treatment (PT) desalinated seawater to control microorganism growth to ensure biological safety. The pH, TDS, alkalinity, Ca2+, Mg2+, Cl−, and SO42− concentration of PT desalinated seawater effluent varies with original water quality and is less affected by the pipe material or disinfectant dose. Polyethylene pipe (PE) is the hardest of the three pipe types for microorganisms to cling to and grow in. Water corrosion is decreased and water chemical stability can be improved by cement mortar lined ductile iron pipe (CMDIP). The epoxy resin-lined ductile iron pipe (ERDIP) involves organic matter dissolution, and the effluent water has a higher turbidity and DOC, affecting biological stability. We provide technical support for water quality regulations and pipe selection for desalinated seawater.

Zincophobic Electrolyte Achieves Highly Reversible Zinc‐Ion Batteries

AbstractZinc metal batteries show tremendous applications in wide‐scale storages still impeded by aqueous electrolytes corrosion and interfacial water splitting reaction. Herein, a zincophobic electrolyte containing succinonitrile (SN) additive is proposed, the SN electrolyte shows a lower affinity for zinc but a stronger affinity for solid‐state interphase (SEI). In the SN electrolyte, zinc hydroxide sulfate (ZHS) is more inclined to accumulate horizontally, forming a dense SEI protective layer on the surface of the Zn anode, effectively slowing down the corrosion of Zn and dendrite growth. The zincophobic SN electrolyte enables excellent performance: zinc plating/stripping Coulombic efficiency of 99.71% for an average of 400 cycles; stable cycles in a symmetric cell for 4000 h (0.9% zinc utilization) and 325 h (86.1% zinc utilization). The soft pack battery using limited zinc delivers maximum energy density of 57.0 Wh kg−1 (based on mass loading of cathode materials and anode materials). Such a simple additive strategy provides a theoretical reference for zinc chemistry in a mild electrolyte environment in practical applications.

Water-Immersion Stability of Self-Compacting Potassium Magnesium Phosphate Cement Paste

For the repair of narrow cracks in concrete, the potassium magnesium phosphate cement (MKPC)-based material paste should have high fluidity and self-compacting ability, making it convenient for pouring and compacting. A self-compacting MKPC paste that meets the index requirements recommended by the European Federation of National Associations Representing for Concrete (EFNAFC) was prepared by increasing the water-cement ratio and adding water glass and fly ash (FA). Specimens of self-compacting MKPC paste were subjected to long-term water corrosion tests, which found that those high-fluidity MKPC paste specimens (reference sample M0) that were produced with only an increased water-cement ratio lost 15-30% of their strength. The residual ratio of folding to compression was 84.6%, and the volume expansion rate was 7.78 × 10-4 after immersion in water for 560 days. The strength residual rate of MKPC slurry (M1) modified by sodium silicate and fly ash is over 90% after 560 days of immersion in water, and the residual rate of flexural-compressive ratio is 101.3%, which meets the requirements of hydraulic cement-based materials. The volume expansion rate of M1 is 5.19 × 10-4, which is 67% of the reference sample M0 with the same water immersion age.