Aren’t you astonished at the vegetables that seem to grow on wastewater?

These green leafy veges are usually difficult to ignore simply because of their size and intense color.

They seem to attract the eyes yet they thrive in what we see as refuse…waste…

This means that there is value in the waste we frown upon.

That sewage, industrial effluent, domestic wastewater seem to carry value is a notion worth investigating further.

AGRICULTURAL NUTRIENTS

Wastewater by itself is a concoction of many things including nutrients that could support agriculture.

Just picture how a body of wastewater turns green over time which is just algae growth being supported by these nutrients.

Nitrogen and phosphorus are key in this regard. 

These pollutants create a myriad of problems including rendering water bodies as dead zones and polluting water with poisonous algae 

So what if we were to recover them and rechannel them back where they are needed?

IN THE FARMS

The phosphorus problem has been made worse by global events such as the Ukrainian war.

But even before this, phosphorus (or P as  it is known in agriculture) seems to be an elusive agricultural input altogether.

The soaring costs of fertilizers seem to be caused by twin problems:

First, since P is mined, it’s price will be on the increase since the deposits are dwindling by the day.

But secondly, it’s high costs are also driven by the excessive losses we see in the farmlands.

Because crops take up P slowly, chances are that it might be washed off by torrential rainfall and deposited in rivers and lakes.

The result is the problem we were talking about earlier – dead zones, algae etc.

But P isn’t only lost from the farmlands.

Domestic waste, sewage and effluent from some industries contain astonishing levels of P.

Take for instance wastewater at the Athi River treatment plant outside Nairobi.

All this points to one thing…

A valuable resource being lost.

So an entrepreneur has an opportunity.

RECOVERY OF P

Phosphorus recovery from wastewater need not be complex.

Several materials have been tested and researched on such as biochar and clays.

So that’s not the issue.

The issue is partnering with producers of this waste so that there’s a constant supply of the raw material– wastewater.

Several firms seem to have found a sweet spot through venturing into domestic wastewater treatment systems.

However, the industrial front is an unexploited space.

There is space for more innovators and makers to take up.

Prototyping, testing and iterating models of P recovery and reuse in agriculture is an area waiting to be exploited.

But it will take forming partnerships with industries and putting a case for treatment of their effluent as a means to generate more income.

So it’s worth the effort because fertilizers are crucial today more than ever.

So if we can derive them from waste, the better.