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The majority of research in the carbon-based nanomaterials (CNMs) field has concentrated on the classification and synthesis of CNMs, with relatively few studies focusing on CNMs' roles in photocatalytic hydrogen production. CNMs have proven their potential as an effective addition to the appeal of photocatalytic hydrogen evolution because of their superior chemical and physical properties. This paper explores the recent advancements in photocatalytic hydrogen (H 2) production utilizing CNMs. As evidenced in the literature, carbon quantum dot (CQD)-sensitized titanium dioxide (TiO 2) can demonstrate to have a photocatalytic hydrogen generation activity of 472 mol g−1 h−1 and 1458 mol g−1 h−1 without and with loading metal co-catalyst (Pt). The optimum catalyst, 0.4 CQD/CdS, contributes to the highest H 2 production rate of 309 mmol g−1 h−1 (apparent quantum yield of 32.6%), which is 1.5 times greater than that of bare CdS. This would significantly accelerate the hydrogen production process. There are still challenges to reaching maximum photocatalytic hydrogen production, including low hydrogen storage. The overall price of hydrogen produced via photocatalysis is also higher because of the energy needed to store the hydrogen. Even though the problem is not directly related to the usage of CNMs, this restriction generates uncertainty and limits commercial investment. Given the rising demand for energy and the trend toward green power, it is recommended that extensive industrial uses of photocatalytic hydrogen produced by employing CNMs be investigated for better and more sustainable energy frameworks. • Recent advances in photocatalytic H 2 production are investigated utilizing CNMs. • The optimum catalyst, 0.4 CQD/CdS can produce the highest H 2 at 309 mmol g−1 h−1. • CQD-sensitized TiO 2 can generate 1458 mol g−1 h−1 photocatalytic hydrogen with Pt. • Photocatalytic H 2 production using CNMs should be investigated for industrial use. [ABSTRACT FROM AUTHOR]

• Seaweed, a marine biomass, identified as an underutilized renewable resource with potential for biofuel. • Seaweed conversion demonstrated to aid carbon sequestration, nutrient recycling, and waste management. • Marine biomass utilization seen as promising yet intricate pathway to global sustainability. • Future research proposed to involve rigorous feasibility analysis and interdisciplinary collaboration. Amid the global energy crisis and environmental concerns, marine biomass, specifically seaweed, serves as a type of marine biomass with potential for conversion into sustainable energy in alignment with the United Nations Sustainable Development Goals (UN SDGs). There is a pressing need to shift towards sustainable energy resources, and seaweed emerges as an underexplored renewable energy source. A thorough analysis of past, current, and emerging trends in seaweed biomass conversion takes place. Thermochemical processes and other conversion methods are detailed, evaluating their efficiencies, limitations, and advancements. Due to its rapid growth and rich carbohydrate content, seaweed proves to be a prime candidate for bioenergy production. Converting seaweed aids in carbon capture, nutrient recycling, and waste management, which positively impacts several UN SDGs. Challenges, including technological barriers, economic feasibility, and environmental concerns related to large-scale seaweed farming and energy conversion, are present. The potential of marine biomass, especially seaweed, in sustainable energy production becomes evident, highlighting its intricate nature. Advancements in conversion technologies, thorough life-cycle assessments, and stringent sustainability protocols are recommended. Future efforts should concentrate on in-depth feasibility studies and foster inter-disciplinary collaborations to address the multifaceted challenges of this energy transition, aligning it with the UN's sustainability aspirations. [ABSTRACT FROM AUTHOR]

• Implications for efficient pyrolysis processes using municipal green waste. • Potential for increased process economics and sustainability. • Optimal parameters boost bio-oil yield (52.8%) and energy efficiency (72.9%). • Holding time enhances bio-oil and syngas yields, while decreases biochar yields. • Smaller feedstock particle size leads to higher energy and exergy efficiency. This study aims to determine how different operating conditions for a fast pyrolysis process employing municipal green waste (MGW) in an auger reactor affect product yields, overall energy efficiency, and total exergy efficiency. In this study, a range of pyrolysis conditions, including temperatures from 400 to 600 °C (in 50 °C increments), holding times from 1 to 5 min (in 1-minute increments), and feedstock particle sizes from 2 to 10 mm (in 2-mm increments) were used. MGW and pyrolysis products were characterised using separate pieces of equipment and in accordance with applicable ASTM standards. The results demonstrate that a yield of 52.8% for bio-oil and a yield of 23.7% for syngas can be achieved at temperatures of 500 and 600 °C, respectively. At 400 °C, the biochar production was highest as 21.5%. Bio-oil and syngas yields improved with holding times, whereas biochar yields declined. At a feedstock particle size of 2 mm, the overall energy efficiency was at its maximum (72.9%), while the total exergy efficiency was also at its highest (68.4%). As feedstock particle size increased, overall energy efficiency and total exergy efficiency dropped. In conclusion, this study provides valuable insights into the effects of different operating parameters on the pyrolysis process using MGW, which can be used to optimize the process and increase its efficiency. [ABSTRACT FROM AUTHOR]

Discharging microplastics into the environment with treated wastewater is becoming a major concern around the world. Wastewater treatment plants (WWTPs) release microplastics into terrestrial and aquatic habitats, mostly from textile, laundry, and cosmetic industries. Despite extensive research on microplastics in the environment, their removal, and WWTP management strategies, highlighting their environmental effects, little is known about microplastics' fate and behaviour during various treatment processes. Microplastics interact with treatment technologies differently due to their diverse physical and chemical characteristics, resulting in varying removal efficiency. Microplastics removed from WWTPs may accumulate in soil and harm terrestrial ecosystems. Few studies have examined the cost, energy use, and trade-offs of large-scale implementation of modern treatment methods for the removal of microplastics. To safeguard aquatic and terrestrial habitats from microplastics' contamination, focused and efficient management techniques must bridge these knowledge gaps. This review summarizes microplastic detection, collection, removal and management strategies. A compilation of treatment process studies on microplastics' removal efficiency and their destiny and transit paths shows recent improvement. Bioremediation, membrane bioreactor (MBR), electrocoagulation, sol-gel technique, flotation, enhanced filtering, and AOPs are evaluated for microplastic removal. The fate and behaviour of microplastics in WWTPs suggest they may be secondary suppliers of microplastics to receiving ecosystems. Innovative microplastic removal strategies and technologies such as nanoparticles, microorganism-based remediation, and tertiary treatment raise issues. These new WWTP technologies are examined for feasibility, limitations, and implementation issues. Pretreatment modifies microplastic size, adsorption potential, and surface morphology to remove microplastics from WWTPs. Membrane bioreactors (MBR) can remove 99.9% of microplastics more efficiently than other approaches. MBR systems require membrane cleaning and fouling control, which raises operational and capital costs. To reduce MPs, plastic alternatives and strict controls, including microplastic waste transformation, should be prioritized. Microplastics must be controlled through monitoring policy execution and awareness. [Display omitted] • Discharging microplastics (MPs) via industrial wastewater is a pressing global issue. • MPs harm soil and ecosystems requiring a search for effective removal technologies. • Membrane bioreactor (MBR) showed effectiveness in removing more than 99.9 % of MPs. • Despite being expensive, bioremediation is demonstrated as an effective approach. • Plastic alternatives and stringent control approaches should be prioritized. [ABSTRACT FROM AUTHOR]