Unit 1: Introduction to reuse

Expected Study Load : 8 hours.


Now that we know how to collect urine and faecal matter, and for a great deal how to treat it, we move to the chapters on how to reuse it in agriculture. Creating a demand is always a good motivation for keeping systems up and running. That can be done through creating a demand for for clean and safe toilets, but also by creating a demand for fertilisers. Fertiliser prices are already high, and prices for local farmers are in general much higher than for large scale farmers in countries with a much better bargaining position. By creating a demand from the agricultural side, there will be more motivation to implement sustainable sanitation - while other needs are met as well.

Fertilisation with wastewater has been common practise - and still is - in many places in the world. By applying sanitatisation processes we can use this process in a safe way.

In this Unit we will discuss first the principles of fertilisers and soil improvers. Then we will zoom into guidelines on reuse, and we will close off with some slides on reusing effluent of wastewater treatment plants in agriculture. There it will be the question on what is your pretreatment: does your treatment plant remove nutrients or not? What about other pollutants? Knowing more about this aspect will also help to making existing (more conventional) forms of sanitation more sustainable.

Learning Objectives:

After completing this unit, you will:

  • know basic agronomic principles of soil fertility, fertiliser types and costs, concept of limiting factor for plant growth, the meaning of NPK 12:5:10 (abbreviation for nutrient content in fertiliser)
  • know the difference between fertiliser and soil conditioner, and why they are both important for plant growth
  • know what are the currently recommended guidelines for using sanitation products in agriculture
  • know what are the common practices in reusing wastewater treatment plant effluent in agriculture.

Relevant links

Part A - Fertiliser and Soil Fertiliser Basics
Part B - Guidelines for reuse
Part C - Reuse of wastewater effluent

Last modified: Thursday, 9 June 2011, 11:08 AM