Effects of Laundry Detergent Residues on Some Biochemical Properties of the Farming Soil and Seeds Germination Rates.

Laundry detergents play a very large role in daily life. Commercial laundry detergent, however, contains many irritating, and potentially toxic ingredients.

The objective of this study is to determine the effects of solution of different powdered laundry detergent (PLD), which is sold by the commercial market, on soil biochemical properties and seed germination rate under greenhouses conditions.

Concentrated detergent solutions (Ccon) have been prepared by taking into consideration the instructions indicated on the packaging of the medium soiled laundry (150 g detergent in 49 L water=3061 mg PLD L^-1) for each of six different PLD’s (D₁, D₂, D₃, D₄, D₅ and D₆). Soils were taken from 0-30 cm depth from experiment sites. Polluted soils with six different concentrated detergent solutions were compared with non-polluted (control) soils about on soil biochemical properties e.g. soil reaction, bacteria and fungi population and basal respiration (CO₂respiration) in two different textured (heavy texture and light texture) soils and four different time periods (0, 30, 60 and 90 days).

In addition; OSSK-596 TAREX corn (Zea mays L.) and LARA bean (Vicia faba) seeds were sown to the planting trays as test crops for germination test in this experiment. Six different concentrated detergent solutions and four different detergent concentrations (C₁: 1 ppm laundry PLD (1780 µl Ccon L^-1 water), C₂: 2 ppm PLD (3561 µl Ccon L^-1 water), C₄: 4 ppm PLD (7123 µl Ccon L^-1water) were applied to the pot soils as irrigation water. We observed seeds germination rates in the planting trays within fifteen days.

The results showed that microbial population and basal respirations of the soils have been shown significant correlation between non polluted and polluted soils with detergent solutions and different time periods in different textured soils.

Ccon applications have been shown a significance (p<0.01) negative effect on bacteria and fungi populations in heavy texture and light texture soils at 0, 30, 60 and 90 days time periods. Ccon applications have been decreased soil bacteria and fungi populations and CO₂respiration in light and heavy textured soils according to control soils. Significant differences were observed among different detergent solutions on seed germination rates. Ccon applications have been increased seed germination rates and shown a positive effect on corn and bean seeds germination rate.

Based on the results of this investigation, it was determined that commercial laundry detergent solutions or residues have a negative impact by depending on detergent type and ingredients of the detergent on soil reaction, microbial population, basal respiration and seed germination rates in polluted soils with detergent solutions.