● Sodium acetate significantly enriched the CGP synthetase-encoding gene.

In the sewage treatment process, facilitating the conversion of pollutants into value-added resources holds great potential for reducing the amount of greenhouse gas emissions and promoting economic circulation. Cyanophycin granule polypeptide (CGP), a recently discovered high value-added biopolymer present in activated sludge, has provided new avenues for the recovery of resources. However, the mechanisms that regulate CGP synthesis and the characteristics of this biopolymer in activated sludge remain unclear thus far. This study investigated the synthesis of CGP, polyhydroxyalkanoates (PHA), and alginate-like exopolysaccharides (ALE) in various microbial aggregates under different carbon sources feeding conditions. Our results showed that the CGP yields was superior that of PHA and ALE when subjected to identical carbon source feeding conditions. Furthermore, biofilm was more conducive to CGP accumulation than floc sludge. Compared with glucose and methanol, sodium acetate significantly enriched the CGP synthetase-encoding gene (cphA_abundance = ~17419), resulting in the highest CGP yield (average 107.1 mg/g MLSS) in both biofilm and floc sludge. This study is the first to reported the characteristic fluorescence of CGP (Ex/Em = ~360/450 nm) caused by the aggregated luminescence of arginine on the side chains. Overall, this study highlights the potential application of CGP as a fluorescent material and offers insights into CGP recovery from activated sludge in wastewater treatment plants.

● The main direct seal up carbon options and challenges are reviewed.

Carbon capture and storage (CCS) technology is an imperative, strategic, and constitutive method to considerably reduce anthropogenic CO₂ emissions and alleviate climate change issues. The ocean is the largest active carbon bank and an essential energy source on the Earth’s surface. Compared to oceanic nature-based carbon dioxide removal (CDR), carbon capture from point sources with ocean storage is more appropriate for solving short-term climate change problems. This review focuses on the recent state-of-the-art developments in offshore carbon storage. It first discusses the current status and development prospects of CCS, associated with the challenges and uncertainties of oceanic nature-based CDR. The second section outlines the mechanisms, sites, advantages, and ecologic hazards of direct offshore CO₂ injection. The third section emphasizes the mechanisms, schemes, influencing factors, and recovery efficiency of ocean-based CO₂-CH₄ replacement and CO₂-enhanced oil recovery are reviewed. In addition, this review discusses the economic aspects of offshore CCS and the preponderance of offshore CCS hubs. Finally, the upsides, limitations, and prospects for further investigation of offshore CO₂ storage are presented.

China has been committed to achieving carbon neutrality by 2060. China’s pledge of carbon neutrality will play an essential role in galvanising global climate action, which has been largely deferred by the Covid-19 pandemic. China’s carbon neutrality could reduce global warming by approximately 0.2–0.3 °C and save around 1.8 million people from premature death due to air pollution. Along with domestic benefits, China’s pledge of carbon neutrality is a “game-changer” for global climate action and can inspire other large carbon emitters to contribute actively to mitigate carbon emissions, particularly countries along the Belt and Road Initiative (BRI) routes. In order to achieve carbon neutrality by 2060, it is necessary to decarbonise all sectors in China, including energy, industry, transportation, construction, and agriculture. However, this transition will be very challenging, because major technological breakthroughs and large-scale investments are required. Strong policies and implementation plans are essential, including sustainable demand, decarbonizing electricity, electrification, fuel switching, and negative emissions. In particular, if China can peak carbon emissions earlier, it can lower the costs of the carbon neutral transition and make it easier to do so over a longer time horizon. China’s pledge of carbon neutrality by 2060 and recent pledges at the 26^th UN Climate Change Conference of the Parties (COP26) are significant contributions and critical steps for global climate action. However, countries worldwide need to achieve carbon neutrality to keep the global temperature from growing beyond the level that will cause catastrophic damages globally.