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Anaerobic digestion found limited use in sludges from industrial wastewater treatment plants (WWTPs). So, it is of interest to assess the biodegradability and co-digestion performance of industrial sludges of biological origin alone and when mixed with municipal sludge. In this study, sludge from two different organized industrial districts (OIDs) and textile industry WWTPs are individually mixed with municipal sludge with and without ultrasound pretreatment to investigate their energy production potential and digestibility using biochemical methane potential tests. Sludges were used at different mass ratios in reactors with F/M ratio of 1. During operation, biogas amount and methane percentage were measured. Before and after reactor operation, total solids (TS), volatile solids (VS), chemical oxygen demand (COD) and pH were measured as performance indicators of digestion. Methane production potential was highest in reactors containing only municipal sludge and lowest containing only industrial sludge. The specific methane production normalized with COD removed for OID I, OID II and textile sludges were 0.13 L/g, 0.11 L/g and 0.11 L/g, respectively; whereas average specific methane production for municipal sludge was 0.31 L/g. COD, TS and VS reductions were lower in industrial sludges compared to domestic sludge. The co-digestion reactors with mixed industrial and municipal sludge performed in accordance with the proportion of two sludges. Ultrasonication improved the digestion performance. Although adding industrial sludge reduced the observed biogas amount to lower than that expected, results show that it is possible to co-digest some industrial sludges with municipal sludge in closely coordinated additions (about

SUMMARY: As human mobility decreased in 2020, the interaction between humans and nature changed significantly. On one hand, water clarity improved in the Amsterdam canals because boat traffic was reduced. On the other hand increased use of fishing water and national parks formed potential threats to the aquatic ecosystems. It is important to use these experiences to foster a more eco-centric mindset, building up to handling handling climate change and future pandemics. ABSTRACT: The anomalous past two years of the COVID-19 pandemic have been a test of human response to global crisis management as typical human activities were significantly altered. The COVID-instigated anthropause has illustrated the influence that humans and the biosphere have on each other, especially given the variety of national mobility interventions that have been implemented globally. These local COVID-19-era restrictions influenced human-ecosystem interactions through changes in accessibility of water systems and changes in ecosystem service demand. Four urban aquatic case studies in the Netherlands demonstrated shifts in human demand during the anthropause. For instance, reduced boat traffic in Amsterdam canals led to improved water clarity. In comparison, ongoing service exploitation from increased recreational fishing, use of bathing waters and national parks visitation are heightening concerns about potential ecosystem degradation. We distilled management lessons from both the case studies as well as from recent literature pertaining to ecological intactness and social relevance. Equally important to the lessons themselves, however, is the pace at which informed management practices are established after the pandemic ends, particularly as many communities currently recognize the importance of aquatic ecosystems and are amenable to their protection.