Waste Technologies of Australia - Water Recovery & Management

AquaMiner

	- What is AquaMiner?
	- Applications
	- Advantages
	- Graphic representation of AquaMiner
	- Background
	- Detailed Description
	- Footprint
	- Competitive Advantages
	- FAQs
	- Product brochure

Detailed AquaMiner Description

Pre-screen
As shown in the diagram, raw sewage is pumped from an existing sewer to the pre-screen consisting of a 200 to 500 micron stainless steel mesh screen. Screened sewage flows through the screen by gravity to the microfiltration feed tank. The pre-screen will remove gross suspended solids (mostly fibrous materials such as toilet paper) and some oil and grease present in sewage. Water sprays are used to wash the solids (screenings) from the screen and are collected in a bin and drained back to the sewer. Hence, there is no handling of the screenings.

Microfiltration
The microfiltration unit consists of thousands of hollow fibre membranes. The membrane wall has microscopic pores generally around 0.2 microns in size (1 micron is 0.001mm). The pre-screened sewage is filtered through the membrane and is collected as filtrate from the inside of the hollow fibre to a filtrate holding tank. Solids that accumulate on the membrane surface are periodically backwashed with a combination of air and filtrate. The backwash wastewater is collected in a storage tank and periodically returned to the sewer. Biofilm formed on the membrane wall through the filtration process will eventually block the membrane if not removed. Filtration performance is maintained by periodical cleaning of the membrane with either an acid or alkali (or combination of both) cleaning solution.

Chemical cleaning is required about every 10 to 14 days and the process is fully automated.

Biofilm film growth may also be controlled by the addition of chlorine to the pre-screened sewage. The chlorine also provides a residual disinfection that prevents recontamination and regrowth of bacteria in the reuse pipe works.

The membrane with 0.2 micron pore size will remove essentially all suspended solids including bacteria which are generally about 1 micron in size. The bulk of the viruses will also be removed as they are mostly attached to suspended solids.

Reverse Osmosis
The reverse osmosis unit uses flat sheet membranes and will not allow any suspended solids to pass through and is also able to remove most dissolved solids and salts. Hence, no bacteria or viruses should pass through the reverse osmosis membrane. The product water (permeate) quality will meet all drinking water criteria except for ammonia. The permeate appearance is similar to typical potable water with colour of about 3 PCU (apparent colour) and turbidity of <0.1 NTU. The dissolved solids content is approximately one tenth of that of typical potable water.