Sewage sludge is a potential precursor for biochar production, but its effective utilization involves costly activation steps. To modify biochar properties while ensuring cost-effectiveness, we examined the feasibility of using seawater as an agent to activate biochar produced from sewage sludge. In our proof-of-concept study, seawater was proven to be an effective activation agent for biochar production, achieving a surface area of 480.3 m²/g with hierarchical porosity distribution. Benefited from our design, the catalytic effect of seawater increased not only the surface area but also the graphitization degree of biochar when comparing the pyrolysis of sewage sludge without seawater. This leads to seawater activated biochar electrodes with lower resistance, higher capacitance of 113.9 F/g comparing with control groups without seawater. Leveraging the global increase in the salinity of groundwater, especially in coastal areas, these findings provide an opportunity for recovering a valuable carbon resource from sludge.

污水污泥是生物炭生产的潜在前体，但其有效利用涉及昂贵的活化步骤。为了在确保成本效益的同时改变生物炭的性能，我们研究了使用海水作为试剂激活污水污泥产生的生物炭的可行性。在我们的概念验证研究中，海水被证明是生产生物炭的有效活化剂，表面积达到480.3 m ²/ g，具有分层孔隙率分布。受益于我们的设计，当比较不含海水的污泥的热解时，海水的催化作用不仅增加了表面积，而且还增加了生物炭的石墨化程度。与不含海水的对照组相比，这导致海水活化的生物炭电极具有更低的电阻和更高的113.9 F / g电容。利用全球（特别是沿海地区）地下水盐度的增加，这些发现为从污泥中回收宝贵的碳资源提供了机会。