Sustainable dual-stage treatment of textile wastewater using Ti-Ti electrocoagulation and activated carbon for water reuse: a comparative study of synthetic and industrial effluent

© 2018 ICE Publishing. All Rights Reserved. The implementation of decentralised wastewater treatment systems, such as biodigesters, septic tanks and treatment ponds, provides opportunities for rural or remote communities to be self-reliant and avoid infrastructural connections to faraway urban areas. However, the effectiveness, sustainability and success of such systems is heavily tied to understanding the overall context (geographical, social, cultural, political and economic) in which they are installed, as well as the ease of their operation and maintenance in the long term. Shortcomings to addressing these aspects can lead to the failure of a project. Using the town of Lobitos, located in the Piura District on the northern coast of Peru, as the case study for this research, this paper is discussing and analysing the use of biodigesters as a more sustainable solution over larger municipal wastewater systems in the context of Lobitos. It explains reasons, such as community engagement, behind past failures of such systems and outlines lessons learned from a practitioner’s perspective. It concludes that addressing the local context as well as considering its impact throughout the project cycle, such as installation and future operation and maintenance, helps to ensure continued delivery of safe and sustainable wastewater treatment.

11 - Sustainable wastewater treatments in textile sector

Microbial fuel cells (MFCs) have been conceived and intensively studied as a promising technology to achieve sustainable wastewater treatment. However, doubts and debates arose in recent years regarding the technical and economic viability of this technology on a larger scale and in a real-world applications. Hence, it is time to think about and examine how to recalibrate this technology's role in a future paradigm of sustainable wastewater treatment. In the past years, many good ideas/approaches have been proposed and investigated for MFC application, but information is scattered. Various review papers were published on MFC configuration, substrates, electrode materials, separators and microbiology but there is lack of critical thinking and systematic analysis of MFC application niche in wastewater treatment. To systematically formulate a strategy of (potentially) practical MFC application and provide information to guide MFC development, this perspective has critically examined and discussed the problems and challenges for developing MFC technology, and identified a possible application niche whereby MFCs can be rationally incorporated into the treatment process. We propose integration of MFCs with other treatment technologies to form an MFC-centered treatment scheme based on thoroughly analyzing the challenges and opportunities, and discuss future efforts to be made for realizing sustainable wastewater treatment.

Microbial-based approaches have emerged as effective solutions for sustainable wastewater treatment and environmental restoration. Bioremediation, utilising diverse microbial agents, is pivotal in mitigating pollution by degrading organic contaminants, reducing heavy metals, and treating industrial and agricultural effluents. This chapter explores innovative microbial strategies, such as biostimulation, bioaugmentation, and biosurfactants produced by strains like Bacillus thuringiensis and Bacillus toyonensis. These biosurfactants demonstrate high stability across varying pH, temperature, and salinity, making them suitable for oil residue and pathogen remediation applications. Additionally, this chapter delves into the symbiotic potential of endophytic microbes, which not only enhance plant resilience to pests but also contribute to bioremediation through the degradation of pollutants in the rhizosphere. Rhizoremediation, a key focus area, emphasises the synergistic interactions between plant roots and microbial communities for contaminant removal. This chapter highlights sustainable wastewater treatment and environmental conservation approaches by examining these microbial insights, promoting a shift towards eco-friendly and biologically-driven solutions.

Microbiome regulation for sustainable wastewater treatment

Wastewater treatment plants can become a source of valuable resources, such as clean water, energy, fuels and nutrients and thus contribute to the sustainable development goals and a transition to a circular economy. This can be achieved by adopting advanced wastewater and sludge treatment techniques. However, these have to be evaluated on their sustainability to avoid any unintentional consequences. Therefore, this paper presents a life cycle sustainability assessment of advanced wastewater and sludge treatment techniques by integrating the environmental, economic and social aspects. The options considered for advanced wastewater treatment are: i) granular activated carbon; ii) nanofiltration; iii) solar photo-Fenton; and iv) ozonation. The technologies for advanced sludge treatment are: i) agricultural application of anaerobically digested sludge; ii) agricultural application of composted sludge; iii) incineration; iv) pyrolysis; and v) wet air oxidation. The results for the advanced wastewater treatment techniques demonstrate that nanofiltration is the most sustainable option if all the sustainability aspects are considered equally important. If, however, a higher preference is given to the economic aspect, ozonation and granular activated carbon would both be comparable to nanofiltration; if the social aspect is considered more important, only activated carbon would be comparable to nanofiltration. Among the sludge treatment methods, agricultural application of sludge is the most sustainable technique for mean-to-high resource recovery. If the recovery rate is lower, this option is comparable with incineration and pyrolysis with high recovery of their respective products. This work helps to identify the most sustainable techniques that could be combined with conventional wastewater treatments for promoting wastewater reuse and resource recovery across a wide range of operating parameters and products outputs. The findings also support the notion that more sustainable wastewater treatment could be achieved by a circular use of water, energy and nutrients contained in urban wastewaters.

The green synthesis of silver nanoparticles (AgNPs) using plant extracts is an eco-friendly method with potential for biomedical and environmental applications. This study aims to synthesize silver nanoparticles (SO-AgNPs) using Salvia officinalis L. extract and evaluate their antioxidant and antibacterial properties, positioning them as candidates for applications in sustainable biomedicine and wastewater treatment. S. officinalis L. extract was used to synthesize AgNPs under optimized conditions, with a 10% extract/AgNO₃ ratio and a reaction time of 180 min. The SO-AgNPs were characterized using ATR-FTIR, XRD, SEM, DLS, and Zeta potential analysis. The antioxidant activity of the extract and SO-AgNPs was evaluated using ABTS+• and DPPH• radical scavenging assays. Antibacterial activity was tested against 11 bacterial strains and bacteria isolated from industrial effluent, with minimal inhibitory concentrations (MIC) determined for both the extract and SO-AgNPs. The SO-AgNPs demonstrated potent antioxidant activity, with IC₅₀ values of 0.233 mg/mL and 0.305 mg/mL in the ABTS+• assay, and 0.173 mg/mL and 0.185 mg/mL in the DPPH• assay for the extract and SO-AgNPs, respectively. Antibacterial testing showed MIC values of 0.25 mg/mL for SO-AgNPs and between 3.12 and 6.25 mg/mL for S. officinalis L. extract against E. coli, P. aeruginosa, A. baumannii, MRSA, B. cereus, and S. epidermidis. For bacteria isolated from industrial effluent, the MIC values were 0.125 mg/mL for SO-AgNPs and 0.5 mg/mL for the extract. This study highlights the dual antioxidant and antibacterial capabilities of S. officinalis L. extract and SO-AgNPs, demonstrating their potential for use in both biomedical and environmental applications, including wastewater treatment.

This study was conducted to assess the effectiveness of a combined green and synthetic solution for the sustainable treatment of wastewater from the paint industry. Effluent was treated with a natural plant extract (Azadarachta indica) and a silver nitrate solution (AgNO3). Three composite samples of wastewater were collected from the paint industry, transferred to the laboratory for analysis, and three case studies were applied for treatment. The parameters of the treated water were compared with the Punjab Environmental Quality Standards (PEQS). Case 1 was a control treatment in which discharged industrial effluent was collected and analyzed for various pollutants (pH, COD, TDS, TSS, and BOD). All the target parameters were higher than the limits in the PEQS. In Case 2, the wastewater was treated by reaction with an A. indica solution for a 4 to 72 h retention time. Some pollutants were remediated as a result of the reaction, while the majority of pollutants required a longer retention time and a higher concentration of A. indica extract, making this case applicable for the treatment of wastewater. In Case 3, the discharged industrial effluent was reacted with A. indica solution combined with AgNO3 solution for wastewater treatment with a 4 to 72 h retention time; after reaction, all the pollutants were remediated at high pH of 12 at a retention time of 24 h. However, a longer retention time and a better solution are required for the treatment of priority pollutants. However, Case 3 treated more pollutants, so was far superior to Cases 1 and 2. As a result, this instance is suitable for the treatment of wastewater from the paint industry.

Increasing emission of greenhouse gases intensifies global warming. To tackle the problem, major economies in the world need to implement policy on energy saving. The wastewater treatment industry, being one of the energy consumers, has developed various technologies to improve energy efficiency and has started to use renewable energy with the aim of achieving energy neutrality in the wastewater treatment process. A literature review found that there is a series of energy-saving methods that can reduce the electricity consumption by 20% in wastewater treatment. Majority of the energy saving comes from energy conservation measures in pumping and aeration systems. In wastewater treatment works, two kinds of renewable energy are usually available, namely solar energy and biogas. The recent development of photovoltaic cells makes it a more practical and financially viable energy source which may cover 40% of the electricity consumption of a wastewater treatment works. Biogas, a by-product generated from the anaerobic digestion process in a wastewater treatment works, can also generate 40% of the electricity required. To achieve energy neutrality, the remaining electricity consumption can be generated through co-digestion of wastewater sludge and organic fraction in municipal solid waste.

Advanced oxidation process for the treatment of industrial wastewater: A review on strategies, mechanisms, bottlenecks and prospects

Sustainable wastewater treatment: How might microbial fuel cells contribute

The environmental, economic, and social dimensions of sustainability, were connected in a systems ecology model with focus on wastewater treatment. Life Cycle Assessment and similar approaches are the most common systems analysis models in the wastewater treatment context. These models are beneficial, but are not the only possible approach to systems analysis. The model in this paper showed that the social and economic dimensions were inseparable intertwined, and both of them dependent on the environmental dimension for ecosystem services in the form of natural resources and regenerating capacity. The holistic view, as applied by a systems ecology approach, put focus on how sustainable wastewater treatment are limited to deliver something that can be assimilated by the environmental systems, and in the best applications, produce something that is again useful to the society

Exploring zeolite-based composites in adsorption and photocatalysis for toxic wastewater treatment: Preparation, mechanisms, and future perspectives

The escalating concern over environmental pollution, particularly stemming from industrial effluents like textile dyes, has necessitated the development of sustainable wastewater treatment methods. This study focuses on utilizing agricultural waste, specifically sterculia foetida shells, to synthesize activated carbon for the removal of Acid Blue 158 (AB 158) dye from aqueous solutions. Through a comprehensive investigation, activated carbon samples were produced using various chemical activating agents and characterized using techniques such as BET surface area analysis, Fourier-transform infrared (FT-IR) spectroscopy, and scanning electron microscopy (SEM). Results indicate that the SFS-AC-K-13 adsorbent exhibited superior adsorption performance, with a maximum dye uptake of 388 mg/g and a removal efficiency of 97.89%, respectively. Equilibrium sorption data were analyzed using Langmuir and Freundlich isotherm models, with the Freundlich model demonstrating the best fit (R2=0.9896) to the experimental data. Comparison with literature values confirms the effectiveness of the synthesized adsorbent in AB 158 dye removal. Overall, this research contributes to sustainable wastewater treatment strategies and highlights the potential of agricultural waste-derived activated carbon for textile dye removal applications.

Electrochemical treatment of industrial wastewater and effluent reuse at laboratory and semi-industrial scale