Simulation of Nutrient Fluxes from Deep Trenched Faecal Sludge with Hydrus-2D

Patrick Adadzi, David Still

Abstract

Ventilated Improved Pit-latrine is a commonly used toilet facility in most developing countries, and faecal sludge accumulating in this facilities need to be disposed carefully in an environmentally safe manner. One such option is through the deep row trenching of ventilated improved pit-latrine (VIP) faecal sludge as nutrients in forest plantations. This experiment was to simulate the process of leachate losses compared to measured values, to determine subsurface losses. The modelling and simulation of the process of water, nitrate and phosphorus transport processes was carried out to monitor changes in concentration over time and to monitor the movement of solutes and any change taking place in the surrounding soil water and groundwater using HYDRUS-2D model. The study demonstrated that the nutrient migration processes can be approximated with the conceptual simplifications of the inputs to the model based on field evidence, soil survey data and applicable literature. The study revealed the presence of sandy alluvial formation at the site, and the presence of unsaturated zone below the entrenched faecal sludge retarded nutrient transport.

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