Environments

Sewage sludge (SS) management and wastewater (WW) treatment remain among the most critical environmental challenges. The pyrolysis of sewage sludge to produce biochar (BC) represents a sustainable and circular strategy for waste valorization and pollution mitigation. This scoping review provides a comprehensive overview of BC derived from SS (BCxSS), with particular emphasis on how pyrolysis conditions affect key physicochemical characteristics such as yield, ash content, pH, surface area, and functional groups. Although substantial research has focused on the removal of heavy metals and organic pollutants using BCxSS, far less attention has been directed toward its potential for pathogen adsorption and inactivation, revealing a notable research gap. Recent studies highlight BCxSS as a versatile material with considerable promise in adsorption and catalysis. However, its application in pathogen removal remains insufficiently investigated, underscoring the need for further investigation into sorption mechanisms and biochar–microbe interactions.

Climate change and unsustainable agricultural practices are triggering land degradation in semi-arid Mediterranean regions. Organic amendments, such as mulching materials, have shown promising potential to mitigate these impacts by improving soil chemical, physical, and biological properties, while enhancing grapevine growth and productivity. This study evaluated the effects of wheat straw mulch (M) and wheat straw combined with biochar (MB), together with vineyard topography (bottom vs. top), on grape chemical and phenolic composition in four Vitis vinifera L. cultivars (Syrah, Trincadeira, Alicante Bouschet, and Antão Vaz) grown in the Alentejo wine region. Grapes were sampled separately at top and bottom topographic positions, and classical and phenolic parameters were analyzed. The application of M and MB significantly modified must composition, mainly through changes in nitrogen and sugar levels across topographic positions. Only MB exhibited stronger effects, enhancing must quality, while MB and M reduced bottom–top variability. Similar patterns and positional effects were observed for phenolic and color parameters. Both organic treatments lowered total monomeric anthocyanin concentrations, although positional differences with wheat straw mulch were found. The results highlight that combining soil management with topography and variety response can optimize grape phenolic composition and promote sustainable viticulture through targeted, site-specific mulching strategies.

With the historical and consistent population declines of the eastern oyster (Crassostrea virginica), restoration projects commonly deploy plastic bags (polyethylene) filled with recycled oyster cultch. Oyster cultch bags are utilized as material to stabilize sediment and provide a substrate for oyster larval recruitment, which provides a habitat for associated organisms and decreases marsh erosion. In addition to the plastic mesh bags utilized to contain oyster cultch, this study also utilized three different biodegradable oyster bag material types (biopolymer, basalt, and cellulose) to determine (1) the influence of bag type on oyster population dynamics, (2) bag durability over time (<1 year), and (3) the cost–benefits for each bag type, calculated via a Weighted Product Model (WPM), within a subsection of the West Galveston Bay Estuary, Texas. For bag type, the results suggested that plastic bags were the most resilient, followed by biopolymer, basalt, and cellulose bags. Plastic bags supported the highest oyster abundance and growth, demonstrating their effectiveness for establishing breakwater reefs. The WPM analysis indicated that plastic bags are inexpensive to deploy and, due to their longevity, are easily monitored over time. However, degradation of plastic bags may introduce microplastics into the environment, posing ingestion risks for bivalves. Whereas the nature-based solutions degraded quickly, inhibiting continuous monitoring, yet the loose cultch may facilitate the natural formation of reefs over time. The results highlight tradeoffs between maximizing oyster recruitment and growth, minimizing environmental contamination, and balancing ecological performance with material sustainability in oyster reef restoration practices.