Liu Jianbo,Lv Gongcheng,Liu Xiaocong,Liu Junpeng,Jia Shouhao
The supernatant fluid and sludge produced by traditional polyacrylamide flocculant (PAM) flocculation of municipal sewage emit a strong odor, and the dewatering performance of flocculant flocculating sludge based on acrylamide as the main synthetic raw material remains undesirable. In this study, we investigated a new green bioflocculant called SDF. This bioflocculant was made using 3-chloro-2-hydroxypropyl-modified starch as the raw material, acrylamide as the monomer, cerium nitrate as the initiator, and dextrin and bone gum as fillers. The results of the study indicated that the SDF-flocculated sludge exhibited a larger pore structure, superior dewatering performance, and a lower intensity of malodorous substances in the supernatant compared to PAM. Furthermore, it was found that the component with the strongest odor in the supernatant detected through purge and trap-gas chromatography–mass spectrometry was ethanethiol, and it was observed that the signal intensity released from the SDF supernatant was 30.62% lower on the first day and 7.91% lower cumulatively over the course of 7 days when compared to PAM. As a consequence, the SDF materials offer promising potential for treating odorous gas and reducing sludge in sewage treatment plants due to their easy fabrication, low cost, and superior dewatering performance.
Shuli Chen,Yongliang Zheng,Chenyang Han,Haoqun Liu,Yi Chen,Jiangang Zhou,Sun Su
Old polyester fibre (OPF) was used for the first reported microbial flocculant (MBF) production by Diaphorobacter nitroreducens R9. Pretreatment of OPF was performed by different bases individually. The optimal pretreatment conditions were determined by total organic carbon (TOC) content of hydrolysate supernatants. Although all alkaline OPF-hydrolysate culture media were investigated for MBF production, KOH hydrolysate produced the highest yield. The influence of KOH OPF-hydrolysate culture condition factors were applied throughout the response surface methodology , and the optimal conditions with the maximum MBF yield (4.02 g/L) were 33.5 °C, pH 9.5, and hydrolysate TOC (4.416 g/L). Furthermore, the MBF was applied to treat polyester alkali-peeling wastewater (PAPW) for the first time, and the highest removal efficiency was achieved when 1.0 g/L MBF was added to PAPW. In general, this contribution reveals that KOH OPF-hydrolysate could be used as a potential inexpensive carbon source for production of MBF by sustainable processes that could reduce environmental pollution .