Contact Lens (CLs) are often disposed of via toilet or sinks, ending up in the wastewater treatment plants(WWTPs). Millions of CLs enter WWTPs worldwide each year in macro and micro sizes. Despite WWTPs'ability to remove solids, CLs can persist and potentially contaminate watercourses and soils. This study evaluates whether different CLs degrade in WWTP aeration tanks. Six daily CLs (Nelfilcon A,Delefilcon A, Nesofilcon A, Stenfilcon A, Narafilcon A, Somofilcon A) and four monthly CLs (Lotrafilcon B,Comfilcon A, Senofilcon A, and Samfilcon A) were immersed in aeration tanks for twelve weeks. Theirphysical and chemical properties, including water content (WC), refractive index (RI), chemical prop-erties (Fourier Transform Infrared Spectroscopy), and mechanical properties were assessed. Results show that all CLs maintained their physical appearance after 12 weeks. Neither Nelfilcon A norNarafilcon A exhibited significant changes in WC and RI, (p>0.05, Tukey test), while other daily lensesshowed variations in at least one parameter. Among monthly CLs, only Senofilcon A showed significant differences in both WC (p0.05 Tukey test). However, Somofilcon A displayed significant changes in stress at break (p<0.0001,Tukey test), and Elongation at Break (p<0.05, Tukey test). No changes were found in the chemicalstructure of any CLs suggesting that twelve weeks in WWTP aeration tanks is insufficient for CLsdegradation. Thesefindings highlight CLs as a potential emerging pollutant, emphasizing their persis-tence in sludge or migration into watercourses and soils (c) 2025 The Authors. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd. Thisis an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

This study investigates the sustainable use of seabed dredged sediments and water treatment sludges as construction materials using combined dewatering and cement stabilization techniques. Dredged sediments and water treatment sludges, typically considered waste, were evaluated for their suitability in construction through a series of dewatering and stabilization processes. Dewatering significantly reduced the initial moisture content, while cement stabilization improved the mechanical properties, including strength and stiffness. The unconfined compressive strength (UCS), shear modulus, and microstructural changes were evaluated using various analytical techniques, including unconfined compression testing, free-free resonance testing, X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). The results show a direct correlation between reduced w/c ratios and increased UCS, confirming the potential of treated sludge as a subbase layer for roads and landfill liners. A chemical analysis revealed the formation of calcium silicate hydrate (CSH) and ettringite, which are critical for strength enhancement. This approach not only mitigates the environmental issues associated with sludge disposal but also supports sustainable construction practices by reusing waste materials. This study concludes that cement-stabilized dredged sediments and water treatment sludges provide an environmentally friendly and effective alternative for use in civil engineering projects.

This review paper explores the use of red mud as a sustainable alternative for construction materials and soil stabilisation due to its unique chemical and mineral composition, a waste produced during the extraction of aluminium from bauxite ore. The disposal of red mud is a major environmental issue worldwide due to its high alkalinity and large production volume. Although this material has already been utilised as construction material (e.g., bricks, cement, concrete), it can also be incorporated for waste water treatment and lead to waste reduction. In soil stabilisation, red mud's alkaline nature, pozzolanic properties, and fine particle size improve soil structure and strength, offering a cost-effective solution. Utilising red mud as a filling material for low-lying areas addresses the disposal problem while contributing to infrastructure development projects. This study highlights construction materials' mechanical properties and durability by incorporating bauxite tailings and also incorporating valorisation of red mud as a precursor for alkali-activated binder. This paper comprises recent research findings and practical applications associated with the use of this waste. Also, it discusses the benefits and challenges associated with the large-scale use of red mud. It gives an idea about how the strength and durability of construction materials can be improved considering overall environmental impact. Future perspectives on policy, technology, and environmental impact are also discussed to provide a comprehensive understanding of red mud's potential for sustainable development. Red mud enhances the properties of materials like strength, durability, and thermal resistance of construction materials like bricks, ceramic, and cement.Red mud increases soil load-bearing capacity, reduces plasticity, and enhances erosion resistance, making it ideal for foundations and road construction.Using red mud reduces dependency on traditional raw materials, conserving natural resources and lowering environmental impacts.Red mud in construction and soil stabilisation contributes to durable, eco-friendly structures and supports sustainable land use.

This study aims to enhance the suitability of expansive clayey soils for use as landfill liners by incorporating water treatment sludge ash (WTSA). Expansive soils, prone to swelling and desiccation cracking, compromise landfill liner integrity, increasing the risk of groundwater contamination. Local soils often do not meet the requirements for hydraulic conductivity and stability, prompting the use of additives like bentonite. However, bentonite-treated soils still face challenges in tropical regions due to moisture loss and cracking. This research investigates the effects of adding WTSA to bentonite-treated soils to mitigate swelling and shrinkage issues. Several geotechnical tests were conducted, including hydraulic conductivity, free swell percentage, swelling pressure, volumetric shrinkage, and desiccation cracking. Results show that WTSA significantly reduces hydraulic conductivity, free swell percentage, and swelling pressure, meeting the standard requirements for liners (hydraulic conductivity of at least 1x10-9 m/s and volumetric shrinkage of at least 4%). Moreover, WTSA addition reduces desiccation cracking to acceptable levels, demonstrating its potential as an effective reinforcement material. This study introduces an innovative approach to using WTSA, a waste product, as a sustainable alternative to conventional liner materials, reducing environmental impact and enhancing landfill liner performance.

This study aimed to develop an energy-efficient process for treating highly saline textile wastewater (TWW) in a 10 m3/day pilot plant and evaluate forage sorghum irrigation with treated wastewater in terms of crop production and soil and irrigation device performance. The TWW treatment pilot plant, consisting of a coagulation/flocculation unit followed by a sand filter and an anion exchange resin column, produced treated effluent that complied with the permissible limits specified in the ISO 16075-2:2020 standard for Category C irrigation water. The corresponding average energy consumption was 1.77 kWh/m3. Reusing treated TWW for forage sorghum irrigation over a 13-week cycle yielded crop performances comparable with freshwater irrigation, with no negative impact on the irrigation system. Although soil profiles were similar between treated TWW and freshwater irrigation, both soils featured an increase in electrical conductivity, which may reversibly or irreversibly affect soil quality and damage salt-sensitive crops. These findings demonstrate the effective treatment and reuse of saline TWW for irrigating salt-tolerant crops, offering significant implications for industrial wastewater management and cropping patterns in arid and semi-arid regions. A 10-m3/day pilot plant was developed for the treatment of highly saline textile wastewater. The pilot plant demonstrated average removal efficiencies of 63% for COD, 97% for colour, 96% for TSS and 21% for EC. Treated effluent met ISO 16075-2:2020 standards for Category C irrigation water, with an average energy consumption of 1.77 kWh/m3. The use of treated wastewater showed sorghum crop production comparable with freshwater irrigation. The use of treated wastewater had no adverse effects on the irrigation system; however, it led to an increase in soil electrical conductivity.

Agricultural waste presents a significant environmental challenge due to improper disposal and management practices, contributing to soil degradation, biodiversity loss, and pollution of water and air resources. To address these issues, there is a growing emphasis on the valorization of agricultural waste. Cellulose, a major component of agricultural waste, offers promising opportunities for resource utilization due to its unique properties, including biodegradability, biocompatibility, and renewability. Thus, this review explored various types of agricultural waste, their chemical composition, and pretreatment methods for cellulose extraction. It also highlights the significance of rice straw, sugarcane bagasse, and other agricultural residues as cellulose-rich resources. Among the various membrane fabrication techniques, phase inversion is highly effective for creating porous membranes with controlled thickness and uniformity, while electrospinning produces nanofibrous membranes with high surface area and exceptional mechanical properties. The review further explores the separation of pollutants including using cellulose membranes, demonstrating their potential in environmental remediation. Hence, by valorizing agricultural residues into functional materials, this approach addresses the challenge of agricultural waste management and contributes to the development of innovative solutions for pollution control and water treatment.

The worldwide pesticide marketplace was approximate 85 billion dollars in 2019, growing at a geometric progression rate of 4.2% from 2015, and by 2023 it is projected to grow at a rate of 11.5% to approximately 130.7 billion dollars. Pesticides' uniqueness is defined by the distinctiveness of their chemistry and their relationship with the environment. Pesticide mobility and bioavailability in water bodies are determined by their desorption and absorption processes from soil particles. Waterbodies are severely affected with the build-up of these poisonous impurities with its imbalance in pH and accumulation of heavy metals, which adversely distress the aquatic ecology in the waterbodies. Pesticides are not only damaging to the ecology of the waterbodies; it is also consequentially harmful to humans. It causes gastrointestinal disorders, cardiac and respiratory issues, and even affects the biotic molecules and organs subsequently leading to acute and/or chronic illnesses. This article reviews 200 scientific literatures for existence of pesticides in drinking water and the various remediation technologies available for the treatment to render the water potable. Upon review of more than 20 technologies, suggestions have been made for the best probable technologies for water with presence of pesticide.

Purpose of ReviewAn increase in the generation of waste within cities is unavoidable due to the increasing global population growth, particularly in urban areas. Municipal wastewater treatment plants (WWTPs) in these urban areas are being pushed to their design limits resulting in issues with WWTP residual management. This paper reviews potential applications of transitioning a municipal WWTP into an urban biorefinery for converting wastes into various value-added chemicals and energy.Recent FindingsPrimary WWTP-based residuals produced are waste-activated sludge, biosolids, grit, and effluent. These components are becoming viable feedstocks for producing many potential products and can be recovered for commercial purposes as opposed to simple disposal. Example products include chemicals, energy, and transportable biofuels. An advantage to biorefinery operations composed of WWTPs is that they provide greener solutions while posing little to no threat to the environment. There has also been an increasing interest in co-feedstocks to WWTPs, such as municipal solids, food wastes, agriculture wastes, and lignocellulosic biomass, which can enhance product yields while providing sustainable management solutions to these additional waste streams.SummaryMunicipal wastewater influents generated within the USA have a chemical energy potential of 1.3 MJ/person/day which represents about 4% of the total daily electricity consumed globally. The cost of waste management is expected to rise by 5.5% by 2027 which can be significantly lowered by having WWTPs integrated into biorefineries. This review found that there is great potential for converting WWTPs into true biorefineries that can effectively produce numerous value-added chemicals. Often, minor process changes can be applied which will yield the envisoned products. This paper provides the framework towards both commercialization opportunities and needed research.

Microplastics in drinking water captured widespread attention following reports of widespread detection around the world. Concerns have been raised about the potential adverse effects of microplastics in drinking water on human health. Given the widespread interest in this research topic, there is an urgent need to compile existing data and assess current knowledge. This paper provides a systematic review of studies on microplastics in drinking water, their evidence, key findings, knowledge gaps, and research needs. The data collected show that microplastics are widespread in drinking water, with large variations in reported concentrations. Standardized methodologies of sampling and analysis are urgently needed. There were more fibrous and fragmented microplastics, with the majority being <10 mu m in size and composed of polyester, polyethylene, polypropylene, and polystyrene. Little attention has been paid to the color of microplastics. More research is needed to understand the occurrence and transfer of microplastics throughout the water supply chain and the treatment efficiency of drinking water treatment plants (DWTPs). Methods capable of analyzing microplastics <10 mu m and nanoplastics are urgently needed. Potential ecological assessment models for microplastics currently in use need to be improved to take into account the complexity and specificity of microplastics.

Resources recovery can improve the economic efficiency and reduce the negative environmental impacts of municipal wastewater treatment plants (MWWTP). The recovered resources can also actively benefit the natural environment enabling a reciprocal relationship between human society and nature. Focusing on these benefits can reveal new resources recovery opportunities. Moreover, for certain environmental impact categories such as emissions of reactive nitrogen, mere damage reduction is insufficient because these emissions are already beyond planetary limits. However, quantitative methods to assess nature benefits are lacking. A new method is developed to calculate the potential nature benefits in three categories: Freshwater restoration, biomass assimilation of nutrients, and soil organic matter sequestration and it is demonstrated on a real-life MWWTP. Focusing on resources recovery helps to purify the wastewater sufficiently for discharge and to benefit the natural environment. Treated wastewater discharge into a river can support freshwater restoration depending on the effluent quality. High quality is achieved by the sufficient removal of the nutrients and organic matter and discharging into a high-flow stream. The recovery of nutrients helps to close the nutrient cycle through biomass assimilation. To maximize this benefit, the nutrient recovery efficiency from the MWWTP must be maximized. But, increasing the nutrient uptake efficiency in agriculture is also crucial, especially for nitrogen. The wastewater sludge products can be applied to soil to sequester organic matter and the products with low volatile solids should be preferred. The development of the new method is a start to recognizing and assessing the potentially positive role of humans in nature.