Abstract:Drainage water from the mandarin canning plants is a type of fruit and vegetable processing wastewater . Since large amounts of organic matter are present in the drainage water from mandarin canning plants, this water was collected separately and analyzed in this study for the first time. The sensory, physicochemical, and microbiological indicators of water quality were studied. The result showed that there are significant differences in the water quality between different processing steps during mandarin canning. The drainage water samples could be classified as mildly, moderately, or severely polluted, based on the comprehensive analysis of the water quality. The drainage water from the third rinsing, sorting/grading, conveying, sterilization, and cooling processing steps could be classified as mildly polluted water, with a small number of visible suspended solids, and the chemical oxygen demand (COD) values were between 31.30 mg/L and 110.35 mg/L. The drainage water from the first and second rinsing processing steps was classified as moderately polluted water, with an increased amount of visible suspended solids, and COD values between 500.40 mg/L and 1515.40 mg/L. The drainage water from acid treatment and alkali treatment processing steps was severely polluted, with a large number of visible suspended solids, and COD values between 6827.80 mg/L and 13207.10 mg/L. The processing steps of the third rinsing, sorting/grading, conveying, sterilization, and cooling accounted for 65% of the total water consumption, and they resulted in mildly polluted drainage water, which could be potentially reused.
