Study on discharge characteristics of fermentor and oak barrel washing wastewater from typical wineries in Ningxia, China.

Wine wastewater management is critical to the sustainable development of the wine industry. In this study, three wineries were selected with growing wine production scales of Ningxia. The number of fermentors and oak barrels washing wastewater were counted during the production period of 2019. The water quality was analyzed and finally the pollutant production was estimated. The results showed that fermentor (barrel) cleaning method greatly influences wastewater amount. The five-step method during fermentor washing stage produced more wastewater than direct high-pressure washing. However, high-temperature fumigation in the oak barrels washing stage can effectively reduce wastewater. The residue of grape juice in fermentors and oak barrels made the main pollutant of washing fermentor (barrel) wastewater COD, and the unit product of washing oak barrels' wastewater produced more COD than washing fermentor wastewater. COD production of washing fermentor wastewater per unit product was ranked as Winery C (412.5 g·kL-1) > Winery B (331.5 g·kL-1) > Winery A (33.6 g·kL-1), in oak barrels washing stage, Winery C (679.2 g·kL-1) > Winery A (507.2 g·kL-1) > Winery B (350 g·kL-1). The results showed that a good linear relationship between annual wastewater production and COD production of the winery (R2 is 0.9777 and 0.9934, respectively). Compared with the first-level standard of cleaner wine production, the production of fermentors and oak barrels washing wastewater in winery accounts for 11-18% of total wine production wastewater, while COD production accounts for 17-43% of total COD.

The transformation and outcome of traditional cassava starch processing in Guangxi, China.

To improve the resource utilization, reduce the pollution generation, and increase the economic benefits of enterprises, a cleaner process to produce cassava starch was proposed based on potato starch processing, and it was applied to the transformation of a traditional cassava starch processing factory in the Guangxi Province in China. The transformation involves the implementation of several new techniques/facilities, including a rasper, horizontal centrifuge, and hydrocyclone. Based on the transformation, typical cassava starch factories in Guangxi were evaluated. The results show that, through the application of a series of cleaner techniques/facilities, the starch recovery rate increased to 84.5%. The water consumption, wastewater generation, and chemical oxygen demand generation decreased by 53.8%, 49.0%, and 20.7%, respectively. Based on the cleaner process, the wastewater can be treated to meet the national discharge standard by using common wastewater treatment technology.

[Selective catalytic oxidation of H2S over supported Fe catalysts on CeO2-intercalated laponite clay].

A series of Fe/CeO2-intercalated clay catalysts were synthesized successfully, the physicochemical properties of the catalysts were characterized by XRD, BET, XRF, TG, FT-IR, O2-TPD, H2-TPR and XPS methods. The catalytic performances for selective catalytic oxidation of H2S were further investigated, all catalysts exhibited high catalytic activities. Among them 5% Fe/Ce-Lap presented the best activity at 180 degreeC and the maximum sulfur yield was up to 96% due to the interaction between iron and cerium, which improved the redox ability of Fe3+ . Moreover, the strong oxygen adsorption capacity and the well dispersion of iron species improved the catalytic performance efficiently.

Selective catalytic oxidation of H2S over iron oxide supported on alumina-intercalated Laponite clay catalysts.

A series of iron oxide supported on alumina-intercalated clay catalysts (named Fe/Al-Lap catalysts) with mesoporous structure and high specific surface area were prepared. The structural and chemical properties were studied by nitrogen sorption isotherms, X-ray diffraction (XRD), UV-vis diffuse reflectance spectra (UV-vis DRS), X-ray photoelectron spectra (XPS), Fourier transform infrared spectroscopy (FTIR), H2 temperature-programmed reduction (H2-TPR) and NH3 temperature-programmed desorption (NH3-TPD) techniques. It was realized that iron oxide mainly existed in the form of isolated Fe(3+) in an oxidic environment. Fe/Al-Lap catalysts showed high catalytic activities in the temperature range of 120-200 °C without the presence of excessive O2. This can be attributed to the interaction between iron oxide and alumina, which improve the redox property of Fe(3+) efficiently. In addition, the strong acidity of catalysts and good dispersion of iron oxide were also beneficial to oxidation reaction. Among them, 7% Fe/Al-Lap catalyst presented the best catalytic performance at 180 °C. Finally, the catalytic and deactivation mechanisms were explored.

[Current research situation of H2S selective catalytic oxidation technologies and catalysts].

This review summarizes and discusses different selective catalytic oxidation technologies and various catalysts for removing H2S, the undesirable byproduct of the fluid catalytic cracking (FCC) processing. Currently the selective oxidation technologies used include Superclaus, Euroclaus, Clinsulf-Do, BSR/Hi-Activity, Selectox and Modop techniques, which have various characteristics and application areas. Catalysts for H2S selective oxidation mainly contain the following systems: carbon, supported SiC, zeolite, oxide, and pillared clay. Former studies focused on carbon and oxide systems. The research interest on zeolite system decreased in recent years, while SiC is regarded as a typical support with great potential for this reaction and continues to be attractive. Pillared clay system is at the preliminary research stage, and is still far from practical application.