Challenges and emerging approaches in life cycle assessment of engineered nanomaterials usage in anaerobic bioreactor

Nanotechnology has wide applications in all areas such as agriculture, the environment, and industry energy pharmaceuticals. The use of nanoparticles (NPs) is increasing, positive and negative effects in various environmental areas, including air, water, and soil, have recently been discovered. Various types of engineered NPs (ENPs) have been used in the renewable energy production system. Anaerobic digestion (AD) process is cost-effective and waste-to-energy production. Different types ENPs are applied in the AD method for improving biogas yield with suitable conditions. ENPs have their excellent performance in understanding their presence, behavior, and impact on water is critical during the AD process. This study aims to understand the consequence of ENPs on the biogas production rate in the AD system. ENPs interaction with bacteria in the AD process for increasing biogas yield rate in the AD process has been discussed. Cost-effective ENPs production, life cycle assessment, and challenges have been elaborated. Finally, the positive effect of ENPs in the AD system for enhancing biogas yield has been conclud

The effects of chemical modification on adsorbent performance on water and wastewater treatment - A review

Current strategies for removing inorganic pollutants from wastewater are expensive, energy-intensive, and necessitate the disposal of producing toxic waste. Hence, there is a need for an effective, selective, and cost-effective adsorbent material. Adsorption has become one of the oldest and most recognized approaches for treating water and wastewater. As an indirect observation, adsorption performance is highly influenced by the surface phenomenon (physical and chemical) of the unmodified and modified precursor. The surface chemistry with the modification method and the material's composition substantially affects the surface's functions. The chemical approach of surface activation is a process that modifies the surface properties and structure of the material to increase the adsorption efficiency. The adsorbent modification could provide a versatile, low-cost, and sustainable solution to pollution of freshwater's inorganic point source. This paper focuses on presenting a comprehensive assessment of the selection and influences of chemical modification on various well-known adsorptive feedstocks

Dyes removal from textile wastewater by agricultural waste as an absorbent – A review

Water pollution from the textile industry affects environmental conditions by generating large-scale effluent mixed with various dyes. Dyes are mostly organics with multiple compound structural and molecular weight variations; if not managed properly before release, they may harm the environment and organism. However, many dyes are categorized into distinct groups, and various adsorbents for dye adsorption have been identified. Among these dyes, methyl dyes, which come in multiple colours, are the most popular in research due to their availability and accessibility. It is imperative to use effective treatments using special adsorbents to remediate water contamination before discharging into streams. As awareness of environmental issues increases with time, the need for a wide range of adaptive alternative feedstock that satisfies ecological regulations has become a priority for researchers worldwide. Therefore, there is a need to develop other adsorbents from alternatively economic raw materials such as locally available industrial and mineral waste and by-products. Additionally, numerous materials have been used, prepared, or grafted from various agricultural peel-based adsorbents. Biomass is a significant source of renewable adsorption processes for hazardous compounds, including toxic organics and metals/elements. It is much cheaper, has abundance, effective adsorption capability, and reusability, have numerous advantages over conventional materials. This review focuses on using plant agricultural wastes to remove dyes. Different adsorption capacities, operating conditions, and application forms have been investigated. The adsorption kinetics and isotherms are demonstrated to illustrate the adsorbent's properties and adsorption mechanisms

Recent advancement and applications of biochar technology as a multifunctional component towards sustainable environment

Biochar is a rich carbon source formed through biomass's thermal decomposition. Biomass-derived biochar is gaining traction in a variety of industries to alleviate the most pressing environmental problems effectively. Biochar development utilizing biomass is generating tremendous attention as a low-cost amendment because of its multiple benefits for urban science, engineering, and the environment and its capability to trap carbon in the soil. Recently, there has been a shortage of specific data connecting biochar applications for environmental development and scientific research in climate change. This article analytically assesses reported studies and examines biochar's role in hydrogel-biochar composite technology, nanotechnology, hazardous pesticide detoxification, and as a nutrient source and a catalyst for various chemical reactions. Biochar's application in modern technological advancements and innovation has a discernible effect on renewable energy and activated carbon production. There is also a discussion of the scientific findings for biochar's capacity to improve agricultural physiology and alleviate salt plant growth and development and its function in promoting animal growth. In summary, biochar has a vast number of possible uses in environmental reduction, and the mechanism by which its performances should be further investigated. Thus, incorporating biochar into the environment appears to be a 'bonus' approach for urban science and engineering technology

Growth profile study of Escherichia Coli K12 by optical density measurement

Bioconversion by microorganisms plays an important role worldwide over chemical transformation. Thus, microbial fermentation offers a significant advantage in producing valueadded products. The biodiesel industry's primary by-product is crude glycerol. The glycerol waste from the biodiesel industry was used as the carbon source for the fermentation process. The biodiesel industry will benefit from the bioconversion of glycerol into valuable chemicals because it is a widely accepted renewable fuel. For the fermentation process for conversion of valuable product, bacteria's stability and growth conditions were monitored using the glycerol as a substrate. Therefore the growth of E.coli cells were required so bacterial growth are commonly analysed using optical density measurements in microbiology. Hence, in the present research focussed on the growth profile study of Escherichia coli K12 by optical density measurement using the spectrophotometer

The synthetization of activated carbon from electrocoagulated palm oil mill effluent sludge for wastewater treatment

Activated carbon (AC) as an adsorbent has been used widely to remove pollutants in wastewater. Many attempts have been made to produce economically accessible AC. This paper explores the idea of producing an AC, a value-added product from the by-product, sludge produced from the electrocoagulation process of palm oil mill effluents (POME) through chemical activation. AC has different applications after its discovery as a solid and reliable adsorbent. Its microporous structure, high surface reactivity, and surface area make it versatile and viable for removing pollutants from aqueous solutions. Electrocoagulation (EC) is a process whereby contaminants are removed by generating an electric current flow through the aqueous solution by using two electrodes made of iron and immersed into the solution. Aside from the wastewater treatment, the resulting by-product of the EC process known as sludge is recovered and converted into AC. POME sludge was utilized as a precursor of AC. The sludge is then carbonized and activated with an activating agent. The activating agents are phosphoric acid (H3PO4) and potassium hydroxide (KOH) solutions. The electrocoagulated sludge-based AC is characterized by its surface characteristics, elemental compositions, surface morphology, and available functional group. To validate the adsorption capacity of electrocoagulated sludge-based AC, textile dye wastewater treatment was carried out to test the efficiency of AC. The AC was used as an adsorbent to test the total suspended solids (TSS) and color removal of textile dye wastewater. The performance of this low-cost AC is comparable to that of many conventional adsorbents. Results indicate that TSS in textile dye wastewater decreased as the adsorbent dosage increased. The values of TSS removal by AC from H3PO4 activation decreased steadily compared to AC from KOH activation. Meanwhile, the color removal percentage decreased when the dye concentration increased. AC from H3PO4 activation has higher color removal percentage compared to AC from KOH activation. This shows that AC from H3PO4 activation has better adsorption due to its more extensive surface area. From BET analysis, AC by H3PO4 activation offers a higher surface area, 36.1017 m3/g, compared to AC by KOH activation, which is 8.9460 m3/g. A more extensive surface area has a higher tendency to adsorb contaminations. The findings of this work confirmed the potential use of electrocoagulated sludge-based AC as an alternative and economically adsorbent for effective dye pollution removal in wastewater

Environmental and economic life cycle assessment of biochar use in anaerobic digestion for biogas production

Due to the increasing demand for sustainable energy sources and effective management of the ever-increasing volume of organic waste, anaerobic digestion (AD) has continued to play a crucial role in biogas production in recent years. Biochar (BC) is a highly flexible material manufactured by carbonizing organic resources like biomass and trash in line with circular economy standards and “tailor-made” for certain purposes. The capacity of BC as an additive to address various well-established crucial difficulties in AD methods has been extensively studied during the last 10 years. Nevertheless, a comprehensive and credible explanation of the BC-AD link remains elusive. The life cycle analysis (LCA) of the biogas enhancement mechanism would provide a quantitative indicator of its long-term viability. The reported LCA studies of AD processes are analyzed in this chapter, showing that few systematic studies cover the whole process; thus results may be inconclusive. LCA results can be influenced by the heterogeneity of the AD method, reactor structure and conditions, and other influences. The absence of a conventional formation for LCAs utilized to the biogas yield method is a component in the inconsistent LCA results. Other considerations for instance systematic maintenance, transportation, system boundaries, temporal units, allocation preference, and waste disposal must be involved in the LCA plan. Notably, the economic pressure of both upstream and downstream systems should be included in the LCA phase. Inevitably, process design, optimization and modeling, and intensification will be the major future research subjects. This chapter provides a thorough and critical examination of the LCA and its sustainability evaluation for the whole AD procedure, which would be helpful in potential research

Challenges and emerging approaches in life cycle assessment of engineered nanomaterials usage in anaerobic bioreactor

Due to the increasing demand for sustainable energy sources and effective management of the ever-increasing volume of organic waste, anaerobic digestion (AD) has continued to play a crucial role in biogas production in recent years. Biochar (BC) is a highly flexible material manufactured by carbonizing organic resources like biomass and trash in line with circular economy standards and \“tailor-made\” for certain purposes. The capacity of BC as an additive to address various well-established crucial difficulties in AD methods has been extensively studied during the last 10 years. Nevertheless, a comprehensive and credible explanation of the BC-AD link remains elusive. The life cycle analysis (LCA) of the biogas enhancement mechanism would provide a quantitative indicator of its long-term viability. The reported LCA studies of AD processes are analyzed in this chapter, showing that few systematic studies cover the whole process; thus results may be inconclusive. LCA results can be influenced by the heterogeneity of the AD method, reactor structure and conditions, and other influences. The absence of a conventional formation for LCAs utilized to the biogas yield method is a component in the inconsistent LCA results. Other considerations for instance systematic maintenance, transportation, system boundaries, temporal units, allocation preference, and waste disposal must be involved in the LCA plan. Notably, the economic pressure of both upstream and downstream systems should be included in the LCA phase. Inevitably, process design, optimization and modeling, and intensification will be the major future research subjects. This chapter provides a thorough and critical examination of the LCA and its sustainability evaluation for the whole AD procedure, which would be helpful in potential research

Advanced techniques in the production of biochar from lignocellulosic biomass and environmental applications

Biochar is a carbon-rich product obtained from the thermochemical conversion of biomass. Utilizing biochar is essential for enhancing economic viability and maintaining the ecology effectively. This work reviews the techniques for producing biochar from various lignocellulosic biomass sources. Pyrolysis technology for converting lignocellulosic biomass into biochar has emerged as a frontier research domain for pollutants removal. The effects of biomass feedstock parameters, production techniques, reaction conditions (temperature, heating rate, etc.), activation, and functional group modification are compared on biochar's physical and chemical properties. This review also focused on environmental applications in several domains, such as agriculture and wastewater treatment. Considering the extensive availability of feedstock, excellent physical/chemical surface properties, and inexpensive cost, biochar has a remarkable potential for removing water pollutants efficiently. Studying the evolution properties of biochar by in-situ or post-modification is of great significance for improving the utilization value of lignocellulosic biomass. Biochar is a valuable resource, yet its application necessitates additional research into its properties and structure, as well as the development of techniques to modify those factors

Co-digestion of domestic kitchen food waste and palm oil mill effluent for biohydrogen production

Biohydrogen production from organic waste not only provides a sustainable way to produce biofuel but it also resolves the growing environmental concerns associated with agro-industrial waste. This research study investigated the biological hydrogen production potential in batch mode through co-digestion of domestic kitchen food waste (DKFW) and palm oil mill effluent (POME) under mesophilic conditions by immobilized Bacillus anthracis bacterial strain. The results showed that hydrogen production from co-digestion of DKFW and POME with an equal proportion of the combination is pH and temperature-dependent. Where, the elevated pH from 4.0 to 5.0 increases hydrogen production significantly; however, increasing the pH > 5.0 reduces productivity. Similarly, by raising the operating temperature from 25 °C to 35 °C the hydrogen production rate (HPR) increases up to 67 mL/h. Apart from hydrogen production, a reduction in chemical oxygen demand (COD) was observed by up to 72 % in this study. The improvement observed for HPR and a significant reduction in COD, suggests that the co-digestion of POME and DKFW is an ideal substrate for hydrogen production at operational temperatures and initial pH of 35 °C and 5.0, respectively. The strategy for utilizing the different organic waste together as a substrate provides a new avenue for the complex substrate for bioenergy production