Smart and sustainable approaches for self-sufficiency: Modeling energy-efficient effluent treatment and water conservation in the pharmaceutical industry.

Zero liquid discharge recovery system for maximized tailings water reuse.

Indias rapid industrial growth has intensified wastewater challenges, with Zero Liquid Discharge (ZLD) systems emerging as a regulatory solution. While ZLD enables partial water recovery, operator insights reveal persistent inefficiencies: 30 50% of wastewater remains unrecycled, often disposed of through unsustainable tanker discharge. High energy costs, heavy chemical use, and frequent breakdowns further undermine its viability, positioning ZLD more as a compliance tool than a sustainable practice. To address these gaps, this study explores sludge valorization as a complementary pathway. Textile effluent treatment plant sludge, after composting, demonstrated significant agronomic potential; enhancing germination, biomass, and yield across diverse crops by 13 40% compared to commercial NPK fertilizers. Laboratory analysis confirmed that heavy metals remained below FAO/WHO safety thresholds, ensuring crop and soil safety. This makes sludge-derived fertilizers safe and viable for farmer use, reducing reliance on costly chemicals. Together, the findings underscore the promise of hybrid models that integrate sludge valorization, innovation, and policy reform for sustainable wastewater management in India

The present study investigates a comprehensive treatment strategy for managing acidic effluent generated during the hydrometallurgical processing of discarded lithium-ion batteries (LIBs), specifically following cobalt oxalate precipitation. The effluent, characterized by extremely low pH (0.1), high total dissolved solids (TDS = 50,000 mg/L), and elevated chemical oxygen demand (COD = 1640 mg/L), was treated through a sequential combination of coagulation, adsorption, and distillation. Coagulation using ferric sulfate achieved 34% TDS reduction through precipitation of dissolved metal ions and oxalates. Subsequent adsorption employing thermally activated carbon derived from waste RO filters further reduced TDS by ~55% due to enhanced surface area and porous structure. Final distillation at 150°C yielded a >99% decrease in TDS and COD, producing condensate meeting CPCB discharge standards (TDS = 79 mg/L, COD = 32 mg/L). The integrated approach effectively transformed a high-strength acidic effluent into reusable water while concentrating recoverable metal residues. A preliminary techno-economic assessment indicated that the process is technically viable and scalable, with energy consumption during distillation being the major cost factor. The study demonstrates a sustainable and resource-efficient treatment pathway for LIB recycling effluents, contributing toward circular economy and zero-liquid discharge objectives.

The mechanical vapor compression (MVC) is an appealing technology for Zero Liquid Discharge (ZLD) processes, particularly in the context of the increasing global demand for freshwater and the protection of the natural environment. This approach supports the development of circular emerging technologies aligned with the Sustainable Development Goals. In this framework, an extended analysis is conducted to evaluate the performance of the MVC system under various operating conditions, with the objective of assessing the impact on energy consumption and distillate production. Reducing the consumption ratio is essential for enhancing process efficiency and advancing a more sustainable process. For this purpose, the paper examines how fluctuations in compressor boundary conditions affect temperatures and pressures. Moreover, feed brine concentration salinity is varied and related to the distillate flow. In the paper, a real ZLD process case study is provided, with experimental data collected. The real data correspond to four different operating conditions (scenarios), verifying that higher evaporation temperatures and lower compression ratio enhance the performance of such systems and lead to increased distillate production. In addition, the energy analysis reveals a consumption range of 165–214 kWh/m3 feed. Incoming electrical conductivities of up to 100 mS/cm are acceptable without scaling, with periodic HNO3 cleanings recommended. The proposed operating ranges can also be applied to other mechanical evaporation systems for wastewater treatment, desalination processes and ZLD technologies, or transferred to other locations.

Membrane distillation crystallization (MDCr) is an approach for treating hypersaline wastewaters and enabling zero-liquid-discharge (ZLD) systems. However, its performance is often inhibited by concentration polarization, scaling, and membrane wetting. Heterogeneous seeding has been proposed to shift crystallization into the bulk phase, yet its quantitative influence on flux stability, wetting resistance, and crystal growth remains poorly understood. This study investigates air-gap MDCr (AGMDCr) of 300 g L−1 NaCl using polypropylene (PP) and polytetrafluoroethylene (PTFE) membranes under seeded and unseeded conditions. Introducing 0.1 g L−1 SiO2 seeds (30–60 µm) enhanced steady-state permeate flux by 41% and maintained salt rejection ≥ 99.99%, indicating effective suppression of wetting. Seeding shifted the crystal size distribution from fine (mean 50.6 µm, unseeded) to coarse (230–340 µm), consistent with reduced primary nucleation and preferential growth on seed surfaces. At 0.6 g L−1, the flux decreased relative to 0.1–0.3 g L−1, consistent with near-wall solids holdup and hindered transport at high seeding concentration. The PTFE membrane exhibited a 47% higher flux than PP, primarily due to its reduced thermal resistance and optimized module geometry at the same flow rate. These results demonstrate that appropriately sized and dosed SiO2 seeding effectively stabilizes flux and suppresses wetting in MDCr.

Resource recovery from potash brine effluent: integrated chemical precipitation and evaporative crystallization for zero liquid discharge and sustainable brine management.

Direct Contact Membrane Distillation–Crystallization (DCMD-Cr) is a synergistic technology for zero liquid discharge (ZLD) and resource recovery from high-salinity brines. In this study, DCMD-Cr was integrated to desalinate real oilfield-produced water (PW) with an initial salinity of 156,700 mg/L. The PW was concentrated to its saturation point of 28 wt.% via DCMD, and the integrated crystallization increased the overall water recovery from 42.0% to 98.9%, with a decline in water flux and salt rejection, mainly due to vapor pressure lowering and scaling. The precipitated salts in the crystallization unit were recovered and identified using different techniques. The results indicated that 91% of the crystals are sodium chloride, and less than 5% are calcium sulfate. A techno-economic analysis (TEA) was performed to evaluate the economic feasibility of the integrated DCMD-Cr process with a 500,000 gallons per day (GDP) capacity. The results showed that the crystallization operating cost was dominant at USD 0.50 per barrel, while the capital cost was only USD 0.04 per barrel. The economic viability can be enhanced by recovering value-added byproducts and using renewable or waste heat, which can reduce the total cost to USD 0.50 per barrel.

ABSTRACT This study presents the design and experimental validation of a photovoltaic-powered, vacuum-assisted solar desalination system optimized for zero-liquid discharge (ZLD) in brackish water treatment. The system integrates a vacuum chamber to lower the boiling point, a brackish water-cooled condenser to enhance condensation, and a capacitor-buffered photovoltaic supply for off-grid operation. It achieved a maximum yield of 20.4 kg/m²/day, about four times higher than a conventional single-basin still under the same conditions. Empirical models predicted production from solar radiation, wind velocity, and energy input with ~10% mean error, mainly due to simplified assumptions. Initial observations confirmed salt crystallization in the basin, indicating ZLD capability, though full recovery was not quantified. Compared with conventional ZLD methods such as vapor compression and electrodialysis, the proposed system offers higher energy efficiency, simpler construction, and modular scalability, making it promising for decentralized desalination in arid and semi-arid regions.

The global distillery industry plays a vital role in numerous economies but also produces large quantities of distillery spent wash (DSW), a highly polluting byproduct known for its high organic load, intense dark color, and low pH. In India alone, distilleries produce approximately 2.75 billion liters of alcohol annually, resulting in 30-45 billion liters of DSW. The dark color, primarily due to melanoidins, poses significant environmental challenges, including reduced light penetration in aquatic ecosystems and soil contamination. This paper provides a comprehensive review of DSW treatment technologies, focusing on color degradation. The review systematically categorizes treatment methods into physico-chemical, biological, and hybrid approaches, detailing their mechanisms, advantages, limitations, and cost-effectiveness. Physico-chemical methods like coagulation-flocculation, electrocoagulation, adsorption, and advanced oxidation processes (AOPs) show varying degrees of success in color and pollutant removal, though challenges like sludge generation and high energy consumption persist. Biological methods, including anaerobic digestion, aerobic treatment, and bioaugmentation, offer sustainable alternatives but are often limited by the recalcitrance of melanoidins. Hybrid methods, combining physico-chemical and biological treatments, demonstrate enhanced efficiency and potential for zero liquid discharge (ZLD). The paper also explores the utilization of treated DSW in agriculture, biogas production, and other valorization pathways, contributing to a circular economy. Despite progress, challenges remain in achieving complete color removal and cost-effective solutions. Future research should focus on developing innovative technologies, optimizing hybrid systems, exploring novel utilization strategies, and creating robust techno-economic models to promote sustainable DSW management practices. The ultimate goal is to transition from a linear waste management approach to a circular economy model, where DSW is viewed as a valuable resource rather than a waste product.

Experimental performance and cost assessment of an energy-efficient zero liquid discharge treatment technology for high-salinity wastewater in arid regions

Demand for polyacrylamide (PAM), has been much raised by the Indonesian government’s which now focusing on downstream mineral processing. Scaling up the company to produce PAM from 15 KTA to 100 KTA presents a significant potential and challenge for a division of SNF Group, a worldwide leader in water-soluble polymer manufacture. However, this raises complex problems requiring strategic reorganization and efficient application of advanced environmental technologies, especially Zero Liquid Discharge (ZLD). This research examines the organizational development necessary to effectively support its production capacity expansion, particularly addressing key challenges in workforce management, organization structure, and skill development. Additionally, the research explores strategic methods by which company can integrate advanced technological innovations, with primary focus on Zero Liquid Discharge (ZLD) technology. This aims to ensure environmental sustainability, maintain compliance with increasingly stringent regulatory requirements, and optimize operational efficiency during the expansion. Primary and secondary data sources were included into a qualitative method. Interviews with important managerial staff from other subsidiaries in China, Korea, India, and top executives from headquarters gathered the primary data. To evaluate internal and external environments impacting PT SPI’s expansion plan, the analytical framework used includes PESTLE, Porter’s Five Forces, VRIO, SWOT analysis, and the TOWS matrix. Based on this thorough study, strategic organizational restructuring is recommended, benchmarked by effective organizational frameworks of SNF China and Korea, implying a workforce scale-up from the current 38 employees to between 75 and 90 personnel. This research especially addresses the junction of organizational growth strategies and sustainability technology adoption in high-growth sectors, therefore greatly adding to strategic management expertise. Practically, the research results offer PT SPI and related companies in the specialty chemicals industry strategic direction and practical insights to help them properly and sustainably negotiate challenging expansions.

Solar-driven zero-liquid discharge (ZLD) is a promising wastewater management strategy for freshwater recovery and salt resource harvesting. However, currently developed interfacial solar crystallizers fail to maintain high evaporation capability when treating hypersaline wastewater due to the salt scaling problem. The accumulated salt on the solar crystallizers hinders the efficiency of solar-driven ZLD. This study reports a solar membrane crystallizer consisting of CuO nanoarrays covered by a hydrophobic and smooth fluoride-co-hexafluoropropylene (PVDF-HFP) coating, capable of preventing salt scaling during desalination. During solar-driven water evaporation, salt crystals migrate and aggregate inward on the crystallizer surface and finally agglomerate together, forming a discontinuous contact with the crystallizer surface. The salt crystals exhibit extremely low adhesion to the crystallizer with adhesive force as low as 1.50 mN mg-1. With this ultralow adhesion, salt crystals can be easily detached from the surface by tilting the solar crystallizer, leaving a regenerated surface that is used continuously. During a 6-hour outdoor test (from 9:30 to 15:30), the solar crystallizer shows a treatment capacity of 7.52kg m-2 for hypersaline wastewater with 25 wt.% salt content under natural sunlight irradiation. This work provides a low-cost and feasible ZLD strategy for sustainable hypersaline wastewater treatment.

Abstract Water demand in the United States is projected to increase by up to 140% by 2050 and 220% by 2070 while climate change will reduce the availability of freshwater in large parts of the country. Here we quantify the magnitude of this challenge and define pathways of sustainable water desalination that can satisfy projected deficits between supply and demand on a US county-level. Simulations using verified models and databases on water, solar and wind resources and prices show the potential of desalination technologies with zero liquid discharge (ZLD), mainly powered by solar and wind energies, sustainably meeting the needs of the municipal, thermoelectric and industrial sectors. This analysis offers a new reference point for supplemental social studies addressing issues and perceptions regarding the sustainability of producing fresh water via desalination.

The pharmaceutical industry significantly contributes to healthcare advancements and the global economy, generating approximately $50 billion annually. However, it also produces around 200,000 tons of pharmaceutical waste per year, including active pharmaceutical ingredients (APIs) and chemical by-products, which pose serious environmental and health risks. India, a major pharmaceutical producer, exports 40% of the world's generic drugs but struggles to manage an estimated 50,000 tons of pharmaceutical waste annually. Current waste management practices remain insufficient, with only 30% of pharmaceutical waste effectively treated in developing nations, leading to contamination, antibiotic resistance, and bioaccumulation. This study explores sustainable waste management strategies, emphasizing waste characterization and treatment. Advanced technologies such as advanced oxidation processes (AOPs) degrade up to 95% of pharmaceutical pollutants, supercritical fluid extraction achieves 98% API removal, and bio-electrochemical systems remove 85% of contaminants. Circular economy principles, including pharmaceutical waste valorization into raw materials, further enhance sustainability. India's Zero Liquid Discharge (ZLD) policy in pharmaceutical hubs like Hyderabad and Gujarat reflects a commitment to waste reduction, though compliance remains below 60%. Lastly, this study highlights the link between waste management and UNSDGs, particularly SDGs 3, 6, 9, and 11-15. Ultimately, strengthening regulatory enforcement and adopting innovative waste treatment solutions can help mitigate environmental and health risks, ensuring a more sustainable pharmaceutical industry, especially in emerging economies like India.

While desalination is a key solution for global freshwater scarcity, its implementation faces environmental challenges due to concentrated brine byproducts mainly disposed of via coastal discharge systems. Solar interfacial evaporation offers sustainable management potential, yet inevitable salt nucleation at evaporation interfaces degrades photothermal conversion and operational stability via light scattering and pathway blockage. Inspired by the mangrove leaf, we propose a photothermal 3D polydopamine and polypyrrole polymerized spacer fabric (PPSF)-based upward hanging model evaporation configuration with a reverse water feeding mechanism. This design enables zero-liquid-discharge (ZLD) desalination through phase-separation crystallization. The interconnected porous architecture and the rough surface of the PPSF enable superior water transport, achieving excellent solar-absorbing efficiency of 97.8%. By adjusting the tilt angle (θ), the evaporator separates the evaporation and salt crystallization zones via controlled capillary-driven brine transport, minimizing heat dissipation from brine discharge. At an optimal tilt angle of 52°, the evaporator reaches an evaporation rate of 2.81kgm-2h-1 with minimal heat loss (0.366 W) under 1-sun illumination while treating a 7 wt% waste brine solution. Furthermore, it sustains an evaporation rate of 2.71kgm-2h-1 over 72h while ensuring efficient salt recovery. These results highlight a scalable, energy-efficient approach for sustainable ZLD desalination.

Concentrated solar supercritical water desalination and multi-effect distillation hybrid systems for efficient zero liquid discharge

Multi-functional solar evaporator towards integrated zero liquid discharge desalination and potassium extraction

The growing reliance on reverse osmosis (RO) in zero liquid discharge (ZLD) and seawater desalination has underscored membrane fouling as a critical challenge, requiring predictive tools for proactive management. This study proposes a novel multidimensional machine learning (ML) framework for forecasting RO performance in industrial ZLD systems. The framework includes data acquisition, feature engineering, ML modeling analysis, multidimensional evaluation, and integrated decision-making, which collectively enable accurate forecasting of fouling-related trends through the prediction of flux and salt rejection. Six ML models were assessed, and the convolutional long short-term memory (ConvLSTM) network exhibited superior performance for midterm (7 d, R2 = 0.942) and short-term (1 d, R2 = 0.960) predictions, capturing spatial and temporal dynamics. For long-term (30 d) forecasting, LSTM and ConvLSTM models achieved comparable performance, confirming suitability for extended prediction horizons. External validation across multiple industrial scenarios demonstrated the adaptability of the framework, enabling selection of optimal models for reliable predictions under diverse operational conditions. These findings demonstrated the capability of the framework to support proactive operational adjustments in response to fouling trends and enhance RO system stability. This study highlights the value of data-driven strategies in supporting operational decisions for industrial wastewater reuse and sustainable ZLD applications.

Abstract Solar‐driven interfacial evaporation has emerged as a sustainable strategy for high‐salinity brine treatment, yet salt crystallization on evaporators severely limits evaporation efficiency and long‐term stability. While most research focuses on enhancing evaporation rates and preventing salt accumulation, the economic and ecological value of simultaneous salt collection is often overlooked. Achieving both efficient evaporation and high salt collection remains a major challenge. Here, we present a tree‐inspired biomimetic evaporator (TBE) is presented that leverages co‐directional Marangoni flows, driven by synergistic thermal and solute gradients, to enable directional salt crystallization and autonomous salt collection. In a one‐week continuous test with 23 wt.% brine, the TBE achieved an exceptional evaporation rate of 6.29 kg m−2 h−1, a salt production rate of 1.08 kg m−2 h−1, an automatic salt detachment rate of 94.1%, and zero liquid discharge (ZLD). Moreover, the TBE exhibited a high freshwater production rate of 4.30 kg m−2 h−1 and a salt collection rate of 0.45 kg m−2 h−1 in outdoor tests. This work provides a scalable, energy‐efficient solution to address both freshwater scarcity and brine pollution, aligning with UN Sustainable Development Goals (SDGs) 6 (Clean Water) and 14 (Life Below Water) by eliminating harmful brine discharge and reducing reliance on fossil fuels.