Sewage Resourcer

System-Introduction

The pre-treated wastewater of about 25 million population equivalents is discharged on the river Rhine. A part of this water is pumped from this river into the dunes along the Dutch coast for the purpose of the potable water supply of Amsterdam and The Hague. More than 2 million people are provided with qualitative superior drinking water.

This drinking water supply of Amsterdam and The Hague is characterised by 50 years of experience. A great amount of data has been gathered during this period. These data show hardly any discontinuities in the quantity and chemical and micro-organic quality of the drinking water during that 50 years, and the water quality always complies with the strict quality requirements set for the water.

The Sewage Resourcer is developed based on the knowledge of and experience with the drinking water supply of Amsterdam and The Hague. The Sewage Resourcer is intended for the potable water supply of cities in tropical or subtropical regions with a shortage of water resources.

The Sewage Resourcer combines the processes of sewage purification and drinking water production in such a way that expensive and complicated tertiary water treatment systems do not have to be installed.

2 The composition of the Sewage Resourcer system

The Sewage Resourcer is composed of three integrated water treatment systems namely:

1 a sewage purification system that removes 95% to 99% of the organic substances in the sewage;

2 an infiltration basin feeded with pre-treated sewage, facilitating water store, removal of nutrients, a decline of water temperature and a dy-off of micro-organisms;

3 a drinking water production facility, fed with water from the infiltration basin;

3 The purpose of the Sewage Resourcer

The purpose of the Sewage Resourcer is:

- qualitative and quantitative superior water supply;

- for cities in tropical and subtropical regions;

- with a shortage of clean water resources;

- at low investment and running costs;

with additional advantages as:

· Improving the quality of surface water by stopping the discharge of raw, un-purified sewage in lakes, rivers, seas etc.

· Preventing the pollution of soil and groundwater resources by stopping the discharge of raw un-purified sewage in the soil.

· Production of agricultural crops in the infiltration fields for the removal of nutrients and improving the soil properties for good infiltration characteristics.

4 System description of sewage purification facilities

The raw un-purified sewage will be transported to the purification facility through a central sewage pipeline. One of the three following sewage purification systems can be selected depending on the required removal of nutrients and organic substances and the need for own power supply:

1 the Pre-fermer®, followed by the De-nutrifier® and sludge fermentation and own power supply

2 a high loaded activated sludge pre-treatment followed by a low loaded De-nutrifier® and sludge fermentation and own power supply

3 the De-nutrifier® in combination with a sludge drying installation and own power supply.

The system choice depends in particular on the requirements on the infiltration water quality, the power supply and nutrient removal.

5 Infiltration basin

The purified sewage is infiltrated in an area selected for that purpose to improve the characteristics of the water so that it is made suitable for human consumption. The following items will be considered, successively

§ The soil characteristics and dimensions of the infiltration basin;

§ The removal of nutrients and the shading through cultivation of the infiltration basin;

§ The system of irrigation and water reclamation;