Selected wastewater parameters from the vegetable washing process

P. Vaculik¹,*, A. Smejtkova¹, M. Prikryl¹, O. Drabek², Z. Votruba¹ and L. Lexa¹

¹ Czech University of Life Sciences Prague, Faculty of Engineering, Department of Building Technological Equipment, Kamýcká 129, 165 21 Prague 6-Suchdol, Czech Republic
² Czech University of Life Sciences Prague, Faculty of Agrobiology, Food and Natural Resources, Department of Soil Science and Soil Protection, Kamýcká 129, 165 21 Prague 6-Suchdol, Czech Republic
* Correspondence: vaculik@tf.czu.cz

Abstract:

This article follows selected parameters in wastewater which arise from the washing process for root vegetables, which is one of those problems which are current in terms of water usage. With a growing population, industrialisation, and urban development, there is also a growing demand for water resources. Industries which are dealing with the processing of agricultural products and food production in general significantly contribute to the growing consumption of water. Technology which is used for cleaning vegetables also significantly affect this growth in water consumption. Increasing demands on the quality of vegetables (eg. the cleanliness of vegetables at the point of sale), also leads to the necessity for more effective postharvest cleaning, something which is carried out both with dry and wet methods. This article examines the cleaning process for selected root vegetables, particularly carrots and potatoes, by determining selected properties of the output process water in an assessed technological line. This line is specific with regard to its methods for cleaning carrots and potatoes. Following the investigation, the line was assessed as being satisfactory with respect to the quality of the input and output water. The monitored parameters of the process water (eg. concentrations of selected elements in the process water and concentrations of selected inorganic anions in the process water, mainly Na and Pb) from cleaning carrots and potatoes were considered as being satisfactory for recirculation into the cleaning process and therefore a reduction was achieved in overall water consumption.

Key words:

food industry, technological line, vegetables, washing vegetables, wastewater

Statistical optimization of agro-industrial diets for the rearing of Cydia pomonella using response surface methodology

J. R. Gnepe¹, R. D. Tyagi¹*, S. K. Brar¹, J. R. Valero¹ and R. Y. Surampalli²

¹INRS Eau, Terre et Environnement (INRS-ETE), 490, de la Couronne, CP 7500,Québec, Canada G1K 9A9; Phone: (418) 654 2617; Fax: (418) 654 2600
²US EPA, P.O. Box-17-2141, Kansas City, Kansas, KS 66117e-mail: gnepej@yahoo.fr; satinder.brar@ete.inrs.ca; tyagi@ete.inrs.ca; josevalero@videotron.ca

Abstract:

In this study, apple pomace and brewery wastewater were used as nutritive agents and as alternative substitutes for the ingredients (soya flour, wheat germ and yeast extract) without affecting the production of the diet. The quantity of agro-industrial waste added during production was based on a regime where the different nutrients were maintained as a constant, such as proteins (3.71 ± 0.09 g), carbohydrates (4.2 ± 0.12 g) and lipids (2 ± 0.08 g) based on their concentration in the standard diet. Various diets produced using different concentrations of waste and ingredients were tested using the culture of Cydia pomonella in order to optimize the diet in terms of nutrition and optimal viscosity (to facilitate assimilation of nutrients). Optimization of the rearing parameters was carried out using response surface methodology. This demonstrated that the brewery wastewater (BWW-SF) diet provided the best results for insect-rearing (81% hatching, 76% larvae and 51% adults) which was closer to the control diet (90% hatching, 80% larvae and 65% adults) and was more significant than the other diets (40–70% hatching, 45–50% larvae and 9–30% adults). In addition, the viscosity was higher in diets where the solids content was higher. The increase in viscosity was in line with the solidification of agar, which evolved rapidly over time and in relation to the solids present in the diet.

Key words: