Effect of polymer and surfactant on bacteria and phage transport in subsurface

Land application of manure, sludge, and wastewater is common in many areas of the world, including the United States. Bacteria, viruses, and other pathogens can be found in these waste materials. In recent years, high molecular weight polymers, such anionic polyacrylamides (PAMs), have been used for soil erosion control. PAM is found to enhance infiltration. A laboratory study was conducted to examine the transport of bacteria and viruses in a tropical soil (an Oxisol) treated with 10 kg/ha of PAM as well as in a control column. In addition, experiments were conducted in laboratory soil columns using a mixture of 10 kg/ha of PAM and 25 mg/L of linear alkylbeneze sulfonate (LAS), a surfactant typically found in wastewaters. Results so far indicate that with a feed solution containing nearly 100 million bacteria or phage particles per mL, no breakthrough was obtained in 4-inch soil columns after passing between 20 and 100 pore volumes of water on a continuous basis. Addition of PAM to soil did not appear to affect bacteria movement in the columns; however, it slightly increased the mobility of phage. High iron oxide content (nearly 17%), high clay content (> 60%), low soil solution pH (∼ 5.5), and an unsaturated transport condition could have been responsible for the retention of the bacteria and phage in the soil columns. Copyright ASCE 2004.