title: Pretreated cheese whey wastewater management by agricultural reuse: chemical characterization and response of tomato plants Lycopersicon esculentum Mill. under salinity conditions.
abstract: The agricultural reuse of pretreated industrial wastewater resulting from cheese manufacture is shown as a suitable option for its disposal and management. This alternative presents attractive advantages from the economic and pollution control viewpoints. Pretreated cheese whey wastewater (CWW) has high contents of biodegradable organic matter, salinity and nutrients, which are essential development factors for plants with moderate to elevated salinity tolerance. Five different pretreated CWW treatments (1.75 to 10.02 dS m(-1)) have been applied in the tomato plant growth. Fresh water was used as a control run (average salinity level=1.44 dS m(-1)). Chemical characterization and indicator ratios of the leaves, stems and roots were monitored. The sodium and potassium leaf concentrations increased linearly with the salinity level in both cultivars, Roma and Rio Grande. Similar results were found in the stem sodium content. However, the toxic sodium accumulations in the cv. Roma exceeded the values obtained in the cv. Rio Grande. In this last situation, K and Ca uptake, absorption, transport and accumulation capacities were presented as tolerance mechanisms for the osmotic potential regulation of the tissues and for the ion neutralization. Consequently, Na/Ca and Na/K ratios presented lower values in the cv. Rio Grande. Na/Ca ratio increased linearly with the salinity level in leaves and stems, regardless of the cultivar. Regarding the Na/K ratio, the values demonstrated competition phenomena between the ions for the cv. Rio Grande. Despite the high chloride content of the CWW, no significant differences were observed for this nutrient in the leaves and stems. Thus, no nitrogen deficiency was demonstrated by the interaction NO3(-)/Cl(-). Nitrogen also contributes to maintain the water potential difference between the tissues and the soil. Na, P, Cl and N radicular concentrations were maximized for high salinity levels (≥2.22 dS m(-1)) of the pretreated CWW.
authors.affiliation: Departamento de Tecnologias e Ciências Aplicadas, Escola Superior Agrária de Beja, Instituto Politécnico de Beja, Rua de Pedro Soares, Apartado 158-7801-902, Beja, Portugal; Departamento de Ingeniería Química y Química Física, Universidad de Extremadura, Avenida de Elvas S/N, 06071, Badajoz, Spain. Electronic address: ana.prazeres@ipbeja.pt.
authors.forename: Ana R
authors.initials: AR
authors.lastname: Prazeres
authors.forename: Fátima
authors.initials: F
authors.lastname: Carvalho
authors.forename: Javier
authors.initials: J
authors.lastname: Rivas
authors.forename: Manuel
authors.initials: M
authors.lastname: Patanita
authors.forename: Jóse
authors.initials: J
authors.lastname: Dôres
mesh_terms: D002611:Cheese; D002712:Chlorides / Q000032:analysis; D018551:Solanum lycopersicum / Q000737:chemistry / Q000187:drug effects / Q000254:growth & development*; D008894:Milk Proteins / Q000737:chemistry; D018515:Plant Leaves / Q000737:chemistry / Q000254:growth & development; D018517:Plant Roots / Q000737:chemistry / Q000254:growth & development; D018547:Plant Stems / Q000737:chemistry / Q000254:growth & development; D011188:Potassium / Q000032:analysis; D059027:Recycling / Q000379:methods; D054712:Salinity; D055049:Salt Tolerance / Q000187:drug effects / Q000502:physiology; D012964:Sodium / Q000032:analysis; D014865:Waste Disposal, Fluid / Q000379:methods; D062065:Wastewater / Q000737:chemistry; D000067816:Whey Proteins
chemical_list: D002712:Chlorides; D008894:Milk Proteins; D011188:Potassium; D012964:Sodium; D062065:Wastewater; D000067816:Whey Proteins
keywords: Dairy effluents; Nutrient competition; Saline wastewater; Sodium accumulation; Tolerance mechanisms; Vegetative tissues