title: Management of wastewater from the vegetable dehydration industry in Egypt--a case study.
abstract: Management of wastewater from the vegetable dehydration industry was the subject of this study. A continuous monitoring programme for wastewater was carried out for almost four months. The characterization of the wastewater indicated that the vegetable dehydration wastewater contains moderate concentrations of organics, solids and nutrients. The wastewater was subjected to three different treatment processes, namely aerobic treatment, anaerobic treatment and chemical coagulation-flocculation treatment. For aerobic treatment, the removal of chemical oxygen demand (COD), biochemical oxygen demand (BOD5) and total suspended solids (TSS) was accomplished within 5 h, and no further reduction was observed after that, with the steady state COD and BOD5 removal efficiencies being 95% +/- 10% and 97% +/- 8%, respectively. For anaerobic treatment, the removal efficiencies for COD, BOD5 and TSS were 67-81%, 70-86% and 56-69%, respectively at hydraulic retention times (HRTs) of 5, 6 and 8 h. Chemical coagulation-flocculation treatment also achieved good results. The COD removal efficiency was 72%, 51% and 75% for ferric chloride (56 g/m3 of wastewater), lime (140 g/m3 of wastewater) and ferric chloride aided with lime (100 g/m3 for ferric chloride and 200 g/m3 for lime), respectively. The corresponding TSS removal values were 92% +/- 17%, 20% +/- 7% and 93% +/- 9%. Based on the available results and the seasonally operated mode of this industry in Egypt, the chemical coagulation-flocculation process is therefore considered to be moste applicable from a technical point of view and for the simplicity of operation and maintenance.
authors.affiliation: Water Pollution Research Department, National Research Centre, El-Tahrir Street, Cairo, Egypt.
authors.forename: Fatma
authors.initials: F
authors.lastname: El-Gohary
authors.forename: Hala
authors.initials: H
authors.lastname: El-Kamah
authors.forename: Rifaat
authors.initials: R
authors.lastname: Abdel Wahaab
authors.forename: Mohamed
authors.initials: M
authors.lastname: Mahmoud
authors.forename: Hamdy A
authors.initials: HA
authors.lastname: Ibrahim
mesh_terms: D000332:Aerobiosis; D000693:Anaerobiosis; D019149:Bioreactors; D003681:Dehydration; D004534:Egypt; D005427:Flocculation; D005525:Food-Processing Industry; D007220:Industrial Waste / Q000032:analysis*; D014675:Vegetables; D018508:Water Purification / Q000191:economics / Q000379:methods*
chemical_list: D007220:Industrial Waste