La planta de tratamiento de aguas residuales industriales de alimentos para mascotas de Mars (China) ha sido completada

Mars Incorporated is an internationally renowned multinational fast-moving consumer goods company, producing and selling a variety of famous brands of chocolate, confectionery, and pet food worldwide. Mars Food (China) Co., Ltd. is Mars' wholly-owned enterprise in China, with numerous well-known domestic and international brands under its umbrella, including Dove chocolate, Snickers chocolate, M&M's chocolate, Skittles, Crunch (crispy rice milk chocolate), Pedigree dog food, Whiskas cat food, and more. Mars began producing pet food in 1935 and was the first company in the world to produce professional pet food. It entered China in 1993, becoming one of the earliest pet food manufacturers in the Chinese market. In 1995, Mars China invested in and established its first pet food factory in Huairou. Currently, the pet care product brands sold by Mars in the national market include Pedigree dog food, Whiskas cat food, Cesar dog food, Eukanuba dog food, Temptations cat food, Iams dog food, and Sheba cat litter. Product categories include dry food, wet food (pouch and canned), treats, and care products, boasting the most diverse and comprehensive range of pet care products in China today. This wastewater project pertains to the food processing wastewater from the Mars Petcare factory in Huairou.

The existing wastewater treatment station at Mars Food was designed with a pretreatment + anaerobic + aerobic process. During current operation, issues such as inefficient skimming in the grease trap, unstable UASB startup, and insignificant flotation process effects have been observed. There is a significant gap between the original process design and its current operation, rendering it unable to meet current operational requirements. Considering reclaimed water reuse and the existing engineering conditions, we propose an upgrade and renovation of the process based on the original system to meet the requirements for reclaimed water reuse. This plan starts from the collection well and includes the process design, equipment, electrical, and automation-related upgrades, maintenance, and equipment commissioning for the entire wastewater treatment system.

The designed treatment capacity for wastewater is 80 tons/day, with the designed influent water quality shown in the figure on the right. The low temperatures in northern winters pose a significant challenge to the stability of biochemical treatment. As an international enterprise, Mars (China) has imposed multi-faceted requirements on our design and construction that exceed industry standards, and demands that the treated wastewater quality meet the standards stipulated in the People's Republic of China's "Water Quality Standard for Reclaimed Water Used in Landscape and Environmental Purposes" GB/T18921-2002 and "Standard for Reclaimed Water Used in Landscape and Environmental Purposes" GB/T18920-2002. The final treated water will be used for landscape water and greening throughout the entire factory area.

A través de experimentos y una serie de argumentos, se han empleado varios métodos de tratamiento para las aguas residuales de producción de alimentos de este proyecto, como el método anaeróbico, el método aeróbico y el método anaeróbico-aeróbico. Estos métodos han logrado diferentes grados de reducción en CODcr y BOD5, pero el efecto en el tratamiento de aceites animales y vegetales no es bueno. Dada la situación real de alto contenido de aceites animales y vegetales en las aguas residuales de producción de esta empresa, se adoptan medidas de pretratamiento de separación de aceite y flotación por aire de alta eficiencia para eliminar la mayor parte de los aceites animales y vegetales de las aguas residuales antes de someterlas a tratamiento bioquímico aeróbico. A través de la depuración y la operación de prueba, el sistema de tratamiento de aguas residuales funciona de manera estable y las aguas residuales tratadas cumplen los requisitos del estándar de descarga.