VOCs治理技术在煤直接液化污水处理工艺中的应用

煤直接液化是将原料煤、氢气、补充硫、催化剂在高温、高压作用下,通过加氢裂化转变为液体燃料的过程。在此生产过程中,产生大量的废水,这些废水具有污染物浓度高、色度深、水质波动大、生物降解难度大等特点。废水集输、储存、处理处置过程中会有大量VOCs逸散,易造成环境污染事件。通过选用先进可靠的废气处理技术,可以有效降低废气的生物毒性,改善员工生产、生活环境,有利于企业及地区整体形象提升。

Combinations of nonstandard finite difference schemes and composition methods with complex time steps for population models

We propose an efficient numerical method for two population models, based on the nonstandard finite difference （NSFD） schemes and composition methods with complex time steps. The NSFD scheme is able to give positive numerical solutions that satisfy the conservation law, which is a key property for biological population models. The accuracy is improved by using the composition methods with complex time steps. Numerical tests on the plankton nutrient model and whooping cough model are presented to show the efficiency and advantage of the proposed numerical method.