Cost-efficient Wastewater Treatment Technologies

Water is a vital component for sustaining life on the earth because it is interacted with all metabolic activities of all living beings (human, plants, and others). The decomposition of organic pollutants, in general, causes oxygen deficiency in water bodies that can lead to severe damages in the ecosystem. Therefore, cost-effective innovative methods for the purification of wastewater is always needed. One of the most important methods that has gathered attention is adsorption. This method has witnessed continuous development in the case of the selected materials as adsorbents. Low cost as well as the production of new nano-materials have been used for the decontamination of water. In this chapter, a general overview based on the information available in the literature was produced to highlight the importance of adsorption as a method for the purification of water from conventional and emerging organic compounds.

Water is one of the life requirements for individuals and societies, and it affects the global economy. The contamination of water is a worldwide problem that threatens the environment and poses abundant hazardous effects on the quality of water and aquatic species. Numerous techniques are known to remove the contaminants from wastewater. Biochar-based material has a novel ability to remediate wastewater due to its distinctive physicochemical properties. It has been considered a promising candidate material for the removal of pollutants through adsorption in the practical application processes. Researchers have reported numerous methods to modify the biochar to enhance their adsorption efficiency. Biochar is considered a cost-effective, environmentally friendly, and sustainable sorbent that has an extraordinary potential to proficiently remove potentially toxic organic and inorganic pollutants from water and wastewater. Adsorption is one of the most efficient techniques to remove pollutants from water and wastewater. These adsorption processes include several mechanisms for the removal of organic and inorganic pollutants as discussed in this chapter. Modified biochar, known also as engineered/designed biochar, has a larger surface area, high adsorption capacity, and predominant surface functional groups that gave a new type of biochar with a great application approach in different wastewater treatment plants compared to natural or pristine biochar. Additionally, the properties of biochar are depended on the type of feedstocks materials and pyrolysis conditions.

In this chapter, the currently available research regarding wastewater treatment using biochar technologies has been reviewed. Specifically, we have critically reviewed the (1) wastewater treatment; (2) production and characterization of biochar; (3) application of biochar for wastewater treatment concerning its role for removal of organic and inorganic pollutants; (4) capacity and mechanism of adsorbing hazardous pollutants from wastewater using biochar. Moreover, the economics and potential risks of biochar in wastewater treatment have been also discussed. This chapter demonstrates the predominant scientific chances for a comprehensive understanding of using biochar as an emerging technique for wastewater treatments. Finally, we also introduced some conclusions and recommendations for further work to enhance the efficiency of biochar for wastewater treatment.

A scarcity of water supply and inadequate wastewater treatment combined with intensified industrial activity have led to increased contamination in lakes, rivers, and other water bodies in developing countries. Nevertheless, some common techniques for wastewater treatment are not practicable for developing countries. The biotechnological approach is considered an important tool for wastewater treatment. The biological method is the method of choice for nutrient removal from wastewater because of its low cost and environmentally friendly. Also, it can be respected as a dynamic force for integrated environmental protection that leads to sustainable development. In this chapter, we show the useful tools of biotechnology to wastewater treatment such as activated sludge, membrane bioreactors, media filters, anaerobic treatment, biosorption, biocatalysts, soil biotechnology, and hydroponic system that are feasible in the context of the developing countries in addition to the role of the genetic engineering in this context.

The increasing environmental pollution because of wastewater generating in industry and municipal urban increases the need for sustainable and cost-effective treatment solutions. This helps to face many challenges in wastewater treatment applications and minimize treatment cost and energy consumption in the treatment phase. Therefore, the application of trickling filter technologies for years ago has provided valuable service in overcoming the above challenges. They have proven to be simple to operate, reliable, energy-efficient, and meet the treatment levels required for many discharge purposes.

This study demonstrates several applications of the trickling filters. These technologies were designed to treat different types of wastewater under different operational applications in different climate conditions. The operating experiences generally show in detail a high rate of efficiency removal of organic content (BOD, COD), nitrogen (TN, NH4), total suspended solids TSS, etc., as a secondary treatment level. Even Trickling Filter is a simple technology, there is a lack of mathematical design and operation experience, as trickling filter mechanics are poorly understood. Therefore, some design criteria, including operation, low energy requirements, and high treatment efficiency were demonstrated and summarized in this Chapter.

Besides, the trickling filter application in this study shows low energy consumption, compared with the activated sludge system solution. Therefore, the case studies in this chapter were considered as the best practice of trickling filter application especially in a hot dry climate where such experience is limited.

Membrane bioreactors (MBRs) for wastewater treatment are being extensively studied and optimized to achieve the following: (a) higher pollutant removal efficiency, (b) better fouling control, (c) lower energy consumption, or (d) higher energy production in MBRs. These efforts have led to the development of a number of alternative advanced configurations of MBR. This chapter presents a review of non-conventional MBR systems, the directions being pursued to develop them further, and a discussion on how these systems can improve the efficiency and other aspects of wastewater treatment.

The chapter highlights new advances in MBRs, specifically in Self-Forming Dynamic Membrane Bioreactors (SFDMBRs) and Electro Membrane Bioreactors (eMBRs). This chapter also presents designs and configurations of novel MBR systems developed for energy production, notably Anaerobic Membrane Bioreactors (AnMBR) and MBR coupled with Bioelectrochemical Systems (MBR-BES) that may be used for simultaneous wastewater treatment and energy harvesting. A comparison of the performances of these advanced MBR systems in terms of conventional and emerging contaminant removal, fouling mitigation, and energy production rates is also provided.

Another part of the chapter examines the economic feasibility of practical applications of advanced configurations of MBR. Particular attention is given to the specific energy demand of the advanced MBRs. Finally, the chapter discusses the challenges encountered in using non-conventional MBRs and their future prospects.

The membrane bioreactor (MBR) process is a ground-breaking innovation in the field of wastewater treatment, which involves a biological activated sludge process coupled with the membrane separation. The main highlights of the MBR are its low footprint, which is due to the elimination of secondary sedimentation process in the conventional activated sludge (CAS). MBR can produce high and consistent effluent quality, which can be a non-potable water source or be readily treated in downstream processes for potable water reuse. With the decrease in the cost of membrane modules over the years, full-scale deployment of MBR plants continues to increase worldwide with scale up to 800 MGD to date. Nevertheless, membrane fouling and energy consumption in MBRs are two technical challenges. MBR membranes are prone to fouling by organic matter originating from the microbial cells. Energy consumption in MBRs is higher than the CAS due to the aeration requirements, particularly for membrane scouring. Several mitigations strategies to address these challenges have been developed, which showed promising results by reducing the operating cost of the MBR plants. These strategies include the development of new membrane materials with chemical and biological resistant properties, novel configurations for enhanced process performance as well as fouling mitigation and control. This chapter aims to present a succinct overview of the status of MBR technology for municipal and industrial wastewater treatment to cover the recent development of energy reduction and fouling mitigation. It is envisioned that MBR will continue as a domain technology in wastewater treatment sector.

Anaerobic digestion (AD) of organic wastes is a popular biological treatment method. It is a useful technology in waste management and environmental health especially for mitigating greenhouse gases (GHSs). It is an economic process that treats a wide range of low- to high-strength organic materials for the production of value-added products such as feed biobased products and bioenergy through a diverse group of microorganisms. Several anaerobic digestion systems have been widely employed to treat both domestic and industrial wastes before they are discharged into the environment. The application of anaerobic technologies is considered a significantly viable economically sustainable system for treatment of both solid and liquid wastes. Its benefits include removal of organic matter, high treatment efficiency, pathogens removal, production of renewable energy, capable of power generation at a low cost, and less biomass production. Nonetheless, this chapter is a review of the following: different anaerobic digestion systems in the treatment of waste products; the bioeconomic and social importance of using anaerobic reactor for biofuel production and methods of identification and quantification of microbial consortia in an anaerobic reactor. The review further highlights the role of different methanogens as the major group of archaea for biogas production. Other ways to increase biofuel generation are also explored. The chapter concludes that environmental and economic challenges in waste management and energy resource scarcity could be alleviated sufficiently using an anaerobic digestion system.

Standing at a second place after agriculture, the textile industries are a source of income to almost 45 million Indian population. Indian textile industries contribute to around 2% of India’s GDP, 15% share in export earning, and 7% of industrial output. However, the alluring benefits delivered by the textile industries are intertwined with severe aquatic pollution, which if remains unchecked would soon prove to be catastrophic for humankind and aquatic life. Textile industries are one of the large consumers of harmful dyes, water, and chemicals. The industrial revolution that has first claimed to be a boon is now standing at the edge of turning into a bane for the marine ecosystem. The unchecked release of textile dyes into the water bodies has resulted in hazardous aftermath primarily for the vital human commodity (water). Synthetic dyes are broadly classified into azo, anthraquinone, and triphenylmethane dyes. The release of colored dyes and its harmful intermediates into the water streams blocks the sunlight, hampering its light penetration and causing disturbance to the ecosystem. Since safe drinking water is one of the most crucial commodities in the developing countries, the water pollution arising from tons of untreated-textile dye discharges needs a spearheaded, efficient, feasible, and eco-friendly approach. In recent decades, several chemical and biological mediated remediation strategies have been reported by several research groups that focused on evading textile dye menace by degrading the harmful chemical dyes into less-harmful forms. This objective has been attained by controlling the physical parameters of effluent such as Chemical Oxygen Demand (COD), Biological Oxygen Demand (BOD), Dissolved Oxygen (DO), Total Dissolved Solids (TDS) content, etc. This chapter discusses the current perspectives and future prospects of textile dyes remediation scenarios in India, and the associated challenges and reasons for its sustainable implementations for the revival of the existing parched marine environment.

The occurrence of xenobiotics in the aquatic environment is a consequence of the development of the chemical and pharmaceutical industries and the massive use of synthetic substances in various manufacturing sectors. It has a completely different effect on the environment than “normal” organic pollution. It does not primarily affect water quality but acts directly on organisms. It can damage immunity, growth, metabolic processes, reproduction, and the natural behavior of biota. The main source of xenobiotics in the water cycle is an outflow of wastewater treatment plants. Xenobiotics are a diverse group of micropollutants with high persistence and resistance to the normal process of biological treatment in WWTP. For this reason, it is necessary to look for and test new methods and possibilities of their elimination in the water management sector. Promising technology is the bioremediation system’s effective use of wood-destroying “white root fungi,” whose enzymatic apparatus is able to metabolize more complex substances.

Providing clean and potable water for human use is a great challenge of the twenty-first century. Globally, water supply wrestles to keep flow with the rapidly increasing demand which is aggravated by global climate change, increasing population and drop-down in water quality. Hence, to enable integrated water management, the need for technological innovation cannot be exaggerated. Nanotechnology shows high potential in improving water and wastewater treatment efficiencies as well as enhancement of water supply by safeguarding unconventional water sources. Therefore, next generation water supply systems can be the result of leapfrogging opportunities provided by advancement in nanotechnology. The sustainability of our current water treatment, their distribution and discharge system are no longer viable due to their dependency on conveyance and centralized systems. The provided review accounts for nanotechnology enabled water treatment solutions through various multifunctional nanomaterials capable of transforming the current water treatment systems. High surface area, tunable pore size, optical, catalytic and magnetic properties, antimicrobial activity and surface chemistry are some of the magnificent properties of nanomaterials which make them a potential candidate for multiple applications. These properties of nanomaterials are applicable in water treatment as adsorbents, sensors for water quality monitoring, disinfection and for preparation of high quality nanomembranes. More importantly, the highly efficient, flexible and multifunctional materials enabled by nanotechnology provide a promising route both to retrofit aging infrastructure and to develop high performance, low maintenance decentralized treatment systems including point-of-use devices.

Recently, electrochemical oxidation water treatment is a promising method to solve environmental pollution issues. During the electrochemical oxidation process, electrode material is a critical factor affecting the treatment efficiency. Sb-doped SnO₂ electrodes are reported as superiors for the decomposition of organic matters from water through the oxidation process. But the weak electrochemical stability is also a drawback of SnO₂ electrodes, which limits their application. This article tries to review SnO₂-based electrodes, which focuses on clarifying their stability and the application in water treatment as well as indicating future research prospects with the aim to highlight the attractive features of this electrode. Specifically, the properties and electrochemical oxidation mechanisms of SnO₂-based electrodes for different pollutants are presented. Furthermore, typical methods for preparation of SnO₂ electrodes along with respective nanostructures synthesized processes are also shown. Moreover, several studies on the application of SnO₂-based electrodes in the treatment of different contaminated-water sources such as textiles, landfills, and phenol wastewaters are reviewed. In addition, recent research trends on development of SnO₂-based electrodes and their recyclability are reported. As a result, this study indicates that the stability and electrochemical performance of SnO₂-based electrodes can be increased by many approaches including doping metal oxide, new fabrication routes, and combining TiO₂ nanotubes with SnO₂. The study also indicates some operational parameters, which need to be considered thoroughly for the practical applicability of SnO₂ electrodes in wastewater treatment.

Chlorine evolution now becomes important in many applications as chemical industry, polymer, pharmaceutical, and water treatment. In chlorine evolution reaction, the RuO₂-based Dimensional Stable Anode is a technologically good and important electrode because of its unique characteristics such as high thermal and chemical stability, low resistivity, and low overpotential. This chapter reviews the chlorine evolution reaction in the RuO₂-based electrode and its application in water treatment, especially in degradation of organic compounds and disinfection. The physicochemical, electrochemical properties and the mechanism of chlorine evolution at RuO₂-based electrode will be summarized in detail. Chlorine evolution reaction mainly happens at the electrode surface. Increasing the chlorine evolution efficiency, the stability and reducing energy consumption become critical issues for the sustainable development of chlorine evolution. The development of nanostructure material for chlorine evolution reaction is a hot topic for wastewater treatment in the near future.

The Gulf Corporation Council (GCC) countries consume approximately half of their oil production for water and energy cogeneration. This intricate situation of increasing water consumption and freshwater scarcity paradox have made wastewater treatment and reuse indispensable. Reuse of treated wastewater contributes to savings fossil fuels and entailed environmental impacts. The objective of this chapter is to demonstrate the application of life cycle assessment (LCA) to evaluate the environmental impact and missed opportunity of treating municipal wastewater to tertiary quality compared to conventional water production. The conventional method compared is the dominant seawater desalination using multistage flash distillation (MSF). The study follows the ISO 14040/44 standards and uses a functional unit of 1 M m³ of tertiary treated effluent (TTE). The modeling concept adopts the cradle-to-gate consequential modeling paradigm. The life cycle inventory is based on filed data collection, reports, literature, and Ecoinvent database processes. The inventories include: infrastructure, grid, materials, energy requirements, chemical additives, and sludge disposal; for primary, secondary, and tertiary treatment. The life cycle impact assessment is applied on both the characterized and normalized level using the ReCiPe method. The normalized results indicate that MSF has over 70 times the impact on fossil depletion and over 8 times the impact on particulate matter formation, human toxicity, and climate change for water production compared to the effects of TTE. The TTE effluent is best for agricultural use.

Cavitation based on advanced oxidation processes (Cav-AOPs) is interesting alternatives for already implemented wastewater treatment technologies. Destructive and strongly undesirable phenomena in the industry, i.e., cavitation, revealed to be useful in a positive manner as a source of energy for chemical reactions. During the implosion of cavitation bubbles, focused energy and resulting high temperature and pressure allows to effectively degrade many chemical compounds present in the cavitated liquid phase. The main reactions taking place in the cavitation zone are the thermal decomposition of chemical moieties as well as oxidation with dissolved oxygen and hydroxyl radicals produced during the implosion of cavitation bubbles. Great interest on this topic is supported by an increased number of publications dedicated to several aspects relating to the formation of cavitation phenomena and its application for water and wastewater treatment as well as hybrid processes based on external oxidants providing effective formation of radical species in cavitation conditions. In this chapter, a state of the art of cavitation-based water treatment technologies, including AOPs, as well as recent trends in this field is discussed. The principles of cavitation combined with AOPs are presented, followed by the evaluation of their effectiveness in the oxidation of organic contaminants. A comparison of hydrodynamic and acoustic cavitation processes for the same type of pollutants has been discussed. For example, the sanitization (disinfection) of water, as well as the degradation of pollutants including sulfide ions and several groups of organic compounds such as sulfur, nitrogen, and oxygen-containing organic compounds, aromatic hydrocarbons, dyes, and pharmaceuticals, has been taken into account while comparing the different cavitation processes.

There is a growing concern about the presence of EOCs in the environment, which could be preferably called “the contaminants of emerging concern,” including pharmaceuticals, specifically antibiotics, antiseptics, hormones, and pesticides that are available commonly in untreated wastewater. These substances that are produced due to various industrial and human activities constitute a significant environmental risk worldwide. Currently, several treatment methods have been investigated for the removal of EOCs that entail different processes (e.g., adsorption, ozonation, and biological) and advanced processes (e.g., advanced oxidation processes and membrane-based technologies). However, these processes often suffer from operational problems and have inadequate treatment capacity when used as stand-alone solutions for all types of EOCs. Due to the fact that EOCs have different physicochemical properties and distinctive toxic concentrations in water, the treatment processes that are combined with innovative technologies and/or materials are required to sustainably remove EOCs at desirable levels. The combined processes are defined as holistic treatment technologies that could synergistically amass several advantages of single processes such as modularity, low cost, and high removal efficiency. Thus, the membrane processes appear as one of the best available technologies to effectively and safely eliminate EOCs due to their improved applicability potential in combined treatments via maximizing the technical performance of overall treatment. This chapter reviews the technological aspects, performances, and economic analysis of EOC removal methods. The innovative or promising combined technologies and membrane processes has been suggested based on the risk groups that rely upon the basic specific properties of EOCs.

Effective wastewater treatment is critical to public health and well-being. The main function of a wastewater treatment plant is to minimize the environmental impact of discharging untreated wastewater into natural water systems. Disinfection is a vital process to inactivate pathogenic microorganisms in drinking water and wastewater. It also acts as the cornerstone unit operation of the water treatment process that secures drinking water safety. Since the 1970s, it has been recognized that disinfection can produce harmful by-products and cause health concerns. Chlorination is the most widely used approach to achieve the disinfection of wastewater but it leads to the formation of disinfection by-products (DBPs) on reaction with the organic matter present. Trihalomethanes (THMs) are the major DBPs formed during the disinfection of water and wastewater. Several water quality operational parameters influence the formation of THMs. The presence of ammonia in wastewater leads to the formation of nitrogenous DBPs in addition to chlorinated and brominated THMs. THMs have been recognized as potential carcinogenic substances, which adversely affects the human health. Owing to the carcinogenic nature of DBPs, guidelines values have been recommended by the regulatory agencies to control their formation and subsequent discharge. The present chapter would describe all the aspects related to THMs formation in wastewater.

Climate change affects significantly the natural water cycle in many locations as projected for the future. Due to the increasing scarcity of water resources, reusing wastewater will become more crucial especially because of climate change acceleration. As well, climate change is one of the main challenges to wastewater treatment systems in the future. On the other hand, greenhouse gas (GHGs) emissions during wastewater treatment can be released into the atmosphere (such as carbon dioxide (CO₂) that results from (oxidation processes), methane (CH₄) that results from anaerobic processes, and nitrous oxide (N₂O) associated with nitrification and denitrification processes). The water demand increased per capita due to the pressures associated with population growth. Thus, many researchers try to address sustainable and green water management approaches that can state the root causes of such challenges. This not only mitigates the climate change impacts on water resources but also facilities using treated wastewater safely in sustainable and greenways.

Environmental problems associated with water sanitation are gradually on increase by superfluous human activities and also due to developmental issues. Wastewater contains various types of pollutants such as pesticides, heavy metals, dyes, and petrochemicals. This has become a global issue for balanced ecosystem since different types of pollutants are responsible for health hazards, owing to their toxicity and poor biodegradability. The removal of these pollutants as well as their sources from water is one of the biggest challenges for both researcher and community. Recently, methods using microbes and microbial products have been employed for the removal of petrochemicals, heavy metals, and pesticides from the water and soil. These methods have been positively used to treat different wastewater types like sewage, sludge, and industrial effluents. There are other treatment approaches also, such as chemical, physical, and other conventional methods, but some of them are not cost effective and some result in secondary pollutants and therefore unsafe to the environment. In this chapter, we will discuss the effective biological treatment approaches, which is bioremediation using microbial biosurfactants. Biosurfactants are the surface-active biomolecules that have several unique properties such as amphipathic in nature, biodegradable, emulsion forming property, tolerant to extreme conditions, and biological origin. Biosurfactants have a great potential for the removal of complex hydrophobic pollutants and pesticides from wastewater because they can be easily interact with those pollutants by their amphipathic nature. It is an extracellularly produced bio-product, and also considered as microbial secondary metabolite which is being produced in the stationary phase of the growth pattern of microbes. Here we have also briefly discussed the production of biosurfactants.

Growing demand for water with its limited resources requires rational water management. The problem of proper water management is not only decreasing fresh water resources, but also its quality deteriorating to an extent that prevents natural self-purification processes. The paper presents the state of water and sewage management in Poland. Particular attention was paid to the issues related to water recovery and reuse. The current state of water and sewage management in Poland, including infrastructure and growing demand for water by various sectors of the national economy requires special attention to water quality. The paper provides a short review of technological processes used in wastewater treatment in Poland. As a case study the issue of recovery of water used in swimming pools and possibilities of its further use were discussed.

The depletion of water has been recognized as the most pressing challenge to socioeconomic and human development. The implementation of Zero Liquid Discharge strategies is essential to drive the transition from linear to circular water management.

Mining ventures require enormous amounts of water and energy in the extraction and transformation phases while generating tremendous volumes of wastewater with a detrimental impact on the environment. By modernization of mining process and implantation of novel technologies (i.e., membrane technologies), there are opportunities such as reduction of water and energy consumption, and extraction of water and valuable components from mine tailings.

For instance, Chile, an arid country experiencing a mega drought, has established the mining sector as the central pillar of its sustainable economic development. However, the intensive mining activities have exacerbated the water-energy nexus. Therefore, a new approach for optimization of water and energy consumption is a necessity for Chile.

This chapter provides the prospects of the exploitation of membrane technologies in the Chilean mining industry, coherently with the Zero-Liquid Discharge paradigm. Besides the traditional practices for freshwater production and remediation, possible applicable strategies are discussed taking into account the recent achievements in membrane technologies for the wastewater valorization by the recovery of valuable minerals.

Recently, increasing the population growth rates has been associated with substantial evolution in urbanization, municipal activities, and the agro-industrial practices. These current progress and developments have contributed to the increase of wastewater disposals, carrying pathogenic organisms and several organic and inorganic pollutants. The design and implementation of wastewater treatment technologies have been upgraded to maintain pollution reduction strategies and cost-saving opportunities. Wastewater treatment systems could be classified into either natural (ecological) or mechanized (equipped) based, mainly according to resource utilization and operating conditions. The natural wastewater treatment systems, such as ponds, wetlands, and retention soil filters, are commonly constructed outdoor from simple and ecological material (sand, gravel, plants, etc.). The engineered systems are used to treat wastewater (primary, secondary, and tertiary processes) by installing several reactors connected to equipment such as pumps, diffusers, heaters, etc. This chapter contains some updates and conclusions acquired from the application of the engineered-based processes in wastewater treatment. Some recommendations that could enhance the performance of mechanized systems in treating different wastewater types to meet the strict national and international regulations are given.