The contemporary world landscape is epitomised by a highly globalised world economy, where neo-liberal agendas push for ultimate competitiveness and much of the manufacturing and production processes have been relocated from core to semi-peripheral countries. To be able to compete in the global arena, many developing nations and newly emerging economies have sacrificed an approach to sustainable development by neglecting social and ecological aspects. A showcase of such unsustainable growth in recent years can be observed in Tirupur, South India. Tirupur’s heavy export orientation of ready-knitted garments transformed it into a major textiles cluster for fashion retailers and buyer groups worldwide. However, the substantial pollution of water resources due to the discharge of raw effluents by processing units into the Noyyal river and the overexploitation of groundwater cast a shadow on the city’s economic expansion. In order to tackle these challenges, a number of regulatory directives were issued from the mid 1990’s onwards, leading to the enforcement of strict Zero Liquid Discharge norms in the cluster. This study investigates whether intervention efforts directed at Tirupur’s textiles sector have been able to address inherent challenges impacting the local environment and population. The findings gathered from an extensive literature review and a field study to Tirupur suggest that while some problems of the past have been attended to, major sustainability issues remain. Serious concerns such as a shift in pollution and economical uncertainty in the cluster have been identified as consequences from the policy interventions.

The goal of this case study was to investigate the behavior of real textile wastewater in DCMD (Direct Contact Membrane Distillation) treatment and subsequently to develop a simple and effective pretreatment for it. To this moment, this work is one of the only studies to make an in-depth analysis of the treatment while considering the complexity of this effluent, which is inherently composed of Volatile Organic Compounds (VOCs) and surfactants. After the application of pretreatment, it became clear that the main concern with textile wastewater treatment using MD is wetting, not fouling. Sedimentation and filtration alone were effective in removing suspended solids, but insufficient in stopping wetting. However, neutralization before sedimentation and filtration was proven to be a fundamental step in reducing wetting rates. This improved performance happens due to the change in pH of the wastewater sample, which increases the rejection rates by the membrane. The best experiments, neutralized to pHs 7.40 and 9.06, achieved up to 99.89% rejection by the membrane, with up to 97% conductivity decrease when compared to an experiment without neutralization, 97% removal of COD, and 98% TOC. Overall, the permeate obtained in this work after pretreatment demonstrated excellent quality, and the recovered effluent can possibly be reused in the textile industry, aiming for Zero Liquid Discharge (ZLD) processes. Thus, scaling up this technology for real industrial use is still necessary, tailoring the treatment to the effluent's characteristics to obtain the best results.

The concept of resource nexus is an acknowledgement of the interconnections between the uses of natural resources. This research will further the work done on the resource nexus by examining the multiple effects of measures taken in the Indian textile industry to lower the costs incurred due to the implementation of Zero Liquid Discharge (ZLD). ZLD combines a variety of technologies to cease the discharge of untreated water from production processes to the surrounding area. The paper will, based on surveys answered by an IKEA supplier and four of IKEA’s sub-suppliers of textile in India, present a multiple case study of possible multiple effects of projects undertaken to lower the increased cost of manufacturing with ZLD. Building on the multiple case study, and marrying it with the knowledge of the multiple benefits of energy efficiency improvements, the Value Added Water (VAW) tool, and the rebound effect, this paper constructs and offers a Multiple Effects Framework (MEF) for measures taken in factories as a response to the increased cost of manufacturing with ZLD. The framework handles both quantifiable and non-quantifiable multiple effects of measures taken, such as changes in resource use (water, energy, chemicals, materials), productivity and work environment. The MEF aggregates a more comprehensive picture of the overall effects of measures taken to adapt to the increased costs associated with ZLD in the textile supply chain, and can to a certain extent be applied to other factories facing a future mandate for ZLD. When changed accordingly, the framework can also be applied to other situations and industries as a decision-making and evaluation tool. In order to deepen the understanding of customer expectations and future trends, interviews were made with IKEA co-workers and a consultant involved with the factories investigated. Lessons learnt by IKEA and the consultant regarding ZLD implementation and the resource nexus are presented for internalization by factories, customers and authorities.

Proper disposal of industrial brine has been a critical environmental challenge. Driven by the even-tightening environment protection regulations, the Zero-Liquid-Discharge (ZLD) has gradually become mandatory option for brine disposal, but its application is limited by the intensive energy consumption. The recent development of solar crystallizer provides a new strategy to achieve ZLD brine disposal. However, the research on solar crystallizer, employing photothermal material to convert solar energy to heat for interfacial brine evaporation and crystallization, is still at the early stage. This dissertation thoroughly investigated the solar crystallizer-based ZLD technology in a broad scientific and application context. The scaling formation while treating real brine, which has been the major barrier to the application of solar crystallizer, was confirmed first with a solar crystallizer device. With a rational designed anti-scaling mechanism, the scaling-free crystallization behavior and stable high water evaporation rate of 2.42 kg m-2 h-1 was achieved when treating real seawater brine. After verifying the feasibility of solar crystallizer towards real brine treatment, its performance was further improved by integrating convective airflow, which provided considerable environmental energy for water evaporation. Both experiment results and COMSOL simulation results confirmed that the maximum environmental energy harvesting can be achieved with the proper size of solar crystallizer. At last, this dissertation pioneered a novel concept of integrating adsorption process into solar crystallizer for simultaneously ZLD brine treatment and potassium extraction. Owing to the special ion concentration behavior of solar crystallizer, the adsorption capacity and selectivity coefficient of absorbent was enhanced by 19.5% and 48.8%, respectively, comparing with traditional bulk adsorption. This dissertation potentially unlocks a new generation of ZLD technology with low carbon footprint and source recovery. More research efforts will be inspired on its applications in real scenarios.

Ensuring electricity availability and acquiring access of potable water during emergencies in remote areas are becoming a global challenge around the world. Utilizing solar energy electricity generation by photovoltaics and clean water production by solar distillation have shown its great potential to meet the world’s future energy and water demands. In this work, we fabricated a photovoltaic-membrane distillation-evaporative crystallizer device (PV-MD-EC), in which high electricity generation efficiency (~15%), clean water production rate (~2.66 kg/m2 h) and salt crystallization from seawater can be achieved in such an integrated system under one sun illumination. In addition, the solar cell operates in a much lower temperature at around 48 oC, which is much lower than previous work. The advanced performance is attributed to the utilization of a highly porous and thinner hydrophobic membrane. This design provides a new strategy to address the challenge of water-energy nexus.

Este trabalho apresenta uma análise de ecoeficiência de cinco cenários de reúso de água a partir do efluente de uma unidade petroquímica para atendimento parcial da demanda de uma torre de resfriamento, dentro da perspectiva de Descarga Zero de Líquidos. O processo-base foi constituído de membranas de osmose reversa, evaporador e cristalizador, e cada cenário foi modelado para um pré-tratamento diferente, abrangendo adição de anti-incrustante, dessupersaturação de íons de bário e coprecipitação de sais de baixa solubilidade para aumento de recuperação de água na osmose. A análise de ecoeficiência foi dividida em duas partes, sendo a primeira uma Avaliação de Ciclo de Vida atribucional com enfoque \'berço-ao-portão\' para avaliação do desempenho ambiental e energético de cada cenário, onde as categorias avaliadas foram: Aquecimento Global, Demanda de Energia Primária, Consumo de Água e Ecotoxicidade de Água Doce. A segunda parte correspondeu a uma análise econômica da instalação e operação da unidade de tratamento e reúso para um horizonte temporal de 9,5 anos. Por conta do pré-tratamento, foi possível aumentar a recuperação de água na osmose de 84% para mais de 94%. As simulações realizadas sobre o sistema de tratamento chegaram em uma recuperação de água de até 99,9% com o efluente do processo apresentando fração de sólidos de até 18,2%, isto é, em um regime muito próximo ao de Descarga Zero. A análise ambiental-energética apresentou forte influência da energia elétrica, consumida sobretudo nas etapas térmicas do tratamento. Além disso, os compostos derivados de cloro usados no pré-tratamento também acrescentaram cargas ambientais significativas. A análise econômica, por sua vez, mostrou que, para o tempo de vida da unidade, os custos de operação têm maior influência no custo total, sendo que a eletricidade consumida nos processos também é responsável pela maior parcela dos gastos. A água de reúso apresentou custo variando entre R$ 3,94/m3 e R$ 6,57/m3, valores estes considerados elevados para a condição brasileira. Na análise unificada de ecoeficiência, houve empate em dois cenários, um com melhor desempenho ambiental-energético e outro com menor custo, sendo que este último foi projetado tendo em vista a redução das cargas ambientais presentes nos demais cenários, mostrando que é possível obter ganhos de rendimento do processo levando-se em conta a variável ambiental. / This work presents an eco-efficiency analysis of five water reuse scenarios in which a petrochemical plant effluent is used to resupply partially the water demand of a cooling tower in a Zero Liquid Discharge perspective. The baseline process was consisted of reverse osmosis membranes, evaporator and crystallizer and each different scenario was modelled for a different pre-treatment, comprising anti-scalant, barium ions desupersaturation and coprecipitation of low-solubility salts for increase water recovery in reverse osmosis. The eco-efficiency analysis was divided in two parts. The first one was composed by an attributional \'cradle-to-gate\' Life Cycle Assessment for the evaluation of environmental and energy performance for Global Warming, Primary Energy Demand, Water Consumption and Freshwater Ecotoxicity impacts. The second part was an economic analysis of the investment and operation costs of the water reuse equipment during a 9.5-years timespan. Because of the pre-treatment, the water recovery in reverse osmosis raised from 84% up to 94%. According to the simulations, it would be possible to reach a water recovery rate of 99.9% and a process effluent with a maximum of 18.2% in solids, i.e., achieving a near Zero Liquid Discharge. The environmental-energy analysis showed strong influences of electric energy consumption, mainly in thermal processes. Furthermore, chemical products used in pre-treatment which are derived from chlorine added some significant environmental burdens. The economic analysis presented major influences of the operating costs on the total treatment plant costs, mostly influenced by energy consumption. The reuse water costs were estimated to be between R$ 3.94/m3 and R$ 6.57/m3, which are excessively high values for the Brazilian situation. The eco-efficiency unified analysis showed similar general results for two scenarios, one with better enviromental-energy performance and the other one with lower costs. This last scenario was projected regarding environmental burdens reduction observed in all other scenarios, from which it can be concluded that it is possible to obtain higher process yields if environmental issues are considered.