Influence of layered degradable straw drainage system on eco-treatment of dredged sludge under vacuum preloading

In response to the long-term non-degradation and environmental pollution caused by the use of horizontal plastic drainage boards, a new approach is proposed in this study, which involves employing horizontal straw drainage system under vacuum preloading treatment for dredging sludge. Through laboratory model tests, the results show that horizontal straw drainage system exhibited excellent performance in treating dredged sludge, with an optimal spacing design of 40-60 cm. During the vacuum preloading test, the straw drainage system continuously degraded, and the degradation by-products of straw, in turn, enriched elements like nitrogen, phosphorus, potassium, etc., in the soil. The two processes of the degradation of straw drainage system and the eco-reinforcement of dredged sludge interacted actively with each other. Finally, a new reinforcement method for on-site dredging sludge was proposed by installing layered straw drainage boards. Therefore, straw drainage system was highly recommended for field application, due to their cost-effective and environmentally friendly characteristics.