Occurrence and transformations of carbon, nitrogen, and phosphorus related to particle size fraction of sweet potato starch wastewater during hydrolytic acidification processes

Abstract

Sweet potato starch wastewater (SPSW) is an industrial food-processing waste product, which is a significant pollution source due to its high chemical oxygen demand (COD), nitrogen, and phosphorus loads. The influence of hydrolytic acidification (HA) process on C, N, and P as well as other main parameters were evaluated. It is essential to treat these wastewaters with effective methods such as HA, a general pretreatment application. In this study, we investigate the scientific link between the changes of different fractions of C, N, and P with particle size distribution in response to the newly introduced HA process. Results showed that the levels of COD, TN, and TP remained ultimately stable; pH and suspended solids (SSs) decreased obviously. HA process exhibits excellent capability of reducing the larger particulars (with diameter of >5 μm) into smaller ones (with diameter of <0.1 μm). The most significant initial concentration contribution to COD, TN, and TP pollution came from particles and matter with a diameter of >5 μm, at 41.8, 57.3, and 43.5%, respectively. While the most significant contribution to COD, TN, and TP was resulting from micro-molecular size particles (<0.1 μm) after 48 h. The smallest particles (<0.1 μm) were the most dominant contribution to all pollutants measured, with COD, TN, and TP contributions of 63.2, 50.4, and 59.3%, respectively. While the contribution of larger particles (particle size >5 μm) reduced to 10.2, 15.3, and 7.1%, respectively.

Effect of Hydrothermal Pretreatment on Anaerobic Digestion of Erythromycin Fermentation Dregs: Biogas Production, Antibiotic Resistance Gene Evolution, and Microbial Community Dynamics

“…After 5 days, all the groups presented positive methane production potential, possibly attributed to the alleviation inhibition of antibiotics which usually inhibited the activity of hydrolysis and acidogenesis bacteria (Tian et al, 2018). As the digestion progressed, the bacterial activity rebounded, and the organic macromolecule decomposes into small molecules, promoting methane production (Zhu et al, 2017).…”

Phosphomolybdic Acid-Catalyzed Oxidative Degradation of Waste Starch: A New Strategy For Handling The Pulping Wastewater

“…The starch, which accumulates abundantly in the papermaking system, has a serious effect on the papermaking production, particularly regarding environmental impact, stability of the system operation, and product quality. Simultaneously, the accumulated starch also causes proliferation of microorganisms (Zhu et al 2017), which results in rot and smell and further deterioration of the production system, the environment, and product quality (Lin et al 2020;Miao et al 2012). Generally, anaerobic fermentation is used for the production of biogas, wastewater treatment, and energy recovery (Chaterjee et al 2019;Sun et al 2011).…”

Extraction and profiling of proteins in yellow powder from sweet potato starch wastewater using response surface methodology and proteomic approach

“…It is estimated that about 15-20 m 3 wastewater was generated to produce 1 ton starch. Direct discharge of the wastewater can cause serious environmental pollution, such as deterioration of water quality, extensive death of fish, shrimp, and shellfish , because it is replete with nutrients and has a high chemical oxygen demand (Guo et al, 2015;Zhu et al, 2017). Various treatments for starch processing wastewater have been developed, including filtration (Li et al, 2020), flocculation precipitation (Li et al, 2020), and biological degradation (Zhong et al, 2017).…”