The straw ammonium sulfite pulp is completely free from chlorine-based bleaching agents

(1) Increasing fertilizer sources: The raw effluent obtained from the ammonium process typically contains 12.8%–14.68% organic matter; these organic components primarily consist of lignosulfonates dissolved in the cooking liquor, reaction products formed with cellulose, as well as lost fine fibers. These organic substances are beneficial for improving soil quality and enhancing soil fertility. Liu Jinsheng and Sun Zhaomin from the Tanghai County Environmental Monitoring Station conducted research on the effects of irrigating rice fields with papermaking wastewater; their results demonstrated that when papermaking wastewater from the ammonium process is mixed with Luan River water at specific ratios, it can increase rice yield by 8–11%.

(2) Expanding the sources of chemical raw materials and accelerating the development of the papermaking industry. The vast majority of paper mills in China utilize caustic soda combined with a small amount of sodium sulfide to produce pulp. Since caustic soda has a wide range of applications, its consumption increases rapidly alongside the rapid growth of the papermaking industry. Compared with the alkali process, the ammonium hydroxide process requires abundant chemical raw material resources and involves simpler solution-based processes; therefore, developing the ammonium hydroxide pulping method holds significant importance for addressing the raw material sourcing challenges faced by the papermaking industry.