Fate of Nutrients, Trace Metals, Bacteria, and Pesticides in Nursery Recycled Water

Yun-Ya Yang,Gurpal S Toor

doi:10.4236/jwarp.2015.74023

Yun-Ya Yang, Gurpal S Toor

Open Access

https://doi.org/10.4236/jwarp.2015.74023

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Abstract

Faced with rapid population growth and fresh water scarcity, reuse of reclaimed water is growing worldwide and becoming an integral part of water resource management. Our objective was to de- termine the fate of nutrients, trace metals, bacteria, and legacy organic compounds (organochlo- rine pesticides) in the recycled water from five commercial nursery ponds in Florida. The pH of recycled water at all sites was 8.1 - 9.3, except one site (6.5), while the electrical conductivity (EC) was 0.31 - 0.36 dS/m. Concentrations of trace metals in recycled water were low: Fe (0.125 - 0.367 mg/L), Al (0.126 - 0.169 mg/L), B (0.104 - 0.153 mg/L), Zn (0.123 - 0.211 mg/L), and Mn (<0.111 mg/L). Total phosphorus (P) and total nitrogen (N) in the recycled water were 0.35 - 1.00 mg/L and 1.56 - 2.30 mg/L, respectively. Among organochlorine pesticides, endrin aldehyde was the only pesticide detected in all nursery recycled water ponds, with concentrations from 0.04 to 0.10 µg/L at four sites and 1.62 µg/L at one site. Other detected pesticides in recycled water were me- thoxychlor, endosulfan sulfate, dichlorodiphenyldichloroethylene (DDE) and α-chlorodane, with concentrations < 0.20 µg/L. Total coliforms and Escherichia coli (E. coli) in recycled water were 20 - 50 colony forming units (CFU)/100 mL. We conclude that the concentrations of various inorganic and organic compounds in recycled water are very low and do not appear to be problematic for ir- rigation purposes in Florida's nursery recycled water ponds.

Highlights

Introduction60% to 90% of available water is used for agricultural purposes [1]. In the United States, approx-How to cite this paper: Yang, Y.-Y. and Toor, G.S. (2015) Fate of Nutrients, Trace Metals, Bacteria, and Pesticides in Nursery Recycled Water
In the world, 60% to 90% of available water is used for agricultural purposes [1]
It is well documented that the ideal pH for most plant production is 5.0 - 6.5 as this provides a balance of availability of essential plant nutrients [19]

Summary

Introduction

60% to 90% of available water is used for agricultural purposes [1]. In the United States, approx-How to cite this paper: Yang, Y.-Y. and Toor, G.S. (2015) Fate of Nutrients, Trace Metals, Bacteria, and Pesticides in Nursery Recycled Water. 60% to 90% of available water is used for agricultural purposes [1]. S. Toor imately 80% of the consumptive water is used in agriculturally related activities [2]. Agricultural and other industries may have to heavily rely on using recycled water to meet crop irrigation needs. Water reuse is a growing practice worldwide and Florida leads the United States in using reclaimed or recycled water [3]. The practice of using reclaimed water for irrigation purposes can result in savings of freshwater supplies and can partially supply some nutrients, nitrogen (N) and phosphorus (P). There are concerns about the impact of the quality of the reclaimed water on crops, soils, and irrigation systems

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