Comments on: Sewerage works taken over by a plant

By: John Hofmeyr

John Hofmeyr — Sat, 15 May 2010 19:19:49 +0000

In case this thread is still open:
During 2009 I was in contact with Working For Water(WfW) about disposal of Water Hyacinth infesting (inter alia) the Hartebeespoort & Roodeplaat Dams in Gauteng. The concept involves co-processing the hyacinth simultaneously with terrestrial invasive & alien vegetation such as sickle-bush, Port Jackson Willow, Black Wattle, Rooikrans etc , as well as feral pine & Eucalypt and chipped sawmill waste. The process involves carbonisation at >300degrees C. Therefore seeds, and any residual viable plant structure would be destroyed.
WfW expressed interest but later backed off claiming “no funds” to support even the transport of sun-dried hyacinth for test carbonisation.
Over the past 2 weeks I have been trying to contact the responsible person at Working for Energy (WfE), which is housed within the South African Energy Research Institute (SANERI). No response there yet, either.

QUESTIONS:
1) I think the moisture content of freshly-collected hyacinth is around 98%? Can this be reduced to <25% before delivery? Sun-drying may be viable in summer but I don't know about winter.
4) What tonnage of hyacinth (dried to <25% moisture) can be delivered to a processing plant if it can be disposed of without charging City of Cape Town any disposal fee. (Tonnage separately for each month of the year to establish seasonality of the arisings. In Gauteng it develops predominantly in summer).

By: MoonDance

MoonDance — Mon, 19 Oct 2009 09:13:19 +0000

I have forwarded your Details on to Asieff Kahn, the Manager of the False Bay Ecology Park as this is his area and hopefully he will contact you soon.

By: Meredith Saul

Meredith Saul — Fri, 02 Oct 2009 21:00:08 +0000

Deeply concerned to hear about the Hyacinth infestation. Not exactly sure what the effects are, but if you guys in the know call it an infestation it can’t be a good thing. Of more concern, is that the city claims it is under-resourced to deal with the problem. Could manual intervention by way of civic mobility be any help ? Possibly person-power by way of schools in the area ? Please let me know, as i am involved with Environmental Education and could possibly help.

Regards,
Meredith Joseph Saul (Head of Geography at Fairmount Secondary School and Zeekoevlei resident)