Potential Impacts of Industrial Reclaimed Water on Landscape Irrigation

Present study was conducted to check the feasibility of industrial reclaimed water (IRW) for irrigation purposes and its impact on plant growth and soil properties. Different types of grass, shrubs, ground cover and trees were grown in three experimental plots. Each plot was subdivided into three subplots for shrubs, ground cover and trees. Plot A was irrigated with industrial reclaimed water (IRW), plot B with (50/50) mixture of both IRW and treated sewage effluent (TSE) and plot C with TSE. Results showed that IRW is highly saline with high sodium (914 mg/L), SAR (42.8) and TDS (3054 mg/L) as compared to TSE (Na 220 mg/L, SAR 8.6 & TDS 1081 mg/L). Plants irrigated with IRW and mixture of IRW and TSE (50/50) indicated mortality rate of 57% and 12% respectively, while plants irrigated with TSE have only 4% mortality. Soil analysis reconfirmed the residual harmful effects of IRW on soil properties as indicated by substantial increase in pH from 8.56 to 10.72, carbonate and bicarbonate from 243 to 728 mg/kg and alkalinity from 220 to 800 mg/kg in soil irrigated by IRW. Notably mortality rate of some salt resistant varieties was less than others. It is concluded that pure IRW is not suitable for irrigation purposes, while mixture of TSE/IRW (50/50) may be fit for salt tolerance varieties. Industrial reclaimed water can be used if the quality of IRW is further improved at industrial wastewater treatment plant or some other amendment techniques as wash down the salts with TSE from root zone. © 2010 Friends Science Publishers