Ha valakinek van türelme és késztetése mélyebben elmerülni a témában, akkor ajánlom ezt a WHO tanulmányt
BGA témában, rövidke 400 oldal:
Toxic
Cyanobacteria in Water: A guide to their public health consequences, monitoring and management (WHO, 1999)
http://www.who.int/water_sanitation_health/resourcesquality/toxcyanbegin.pdf
Érdekes fejezetek:
Chapter 2.
Cyanobacteria in the environment
Chapter 3. Cyanobacterial toxins
Chapter 4. Human health aspects
Chapter 5. Safe levels and safe practices
5.1.4 Recreational water exposure (avagy az akvakertészet veszélyei)
5.3.3
Cyanobacteria sold as dietary supplements
5.4 Tastes and odours (a szag és a mérgezőség összefüggései)
Chapter 8. Preventative measures (A számunkra legfontosabb fejezet)
Chapter 9. Remedial measures
A Hatékony Megelőzési Módok
1. Fény kontroll
2. Tápanyag kontroll (nitrogén és foszfor-vegyületek)
Részletek a 8-as fejezetben.
A Hatékony Ellenszerek
Amit eddig leszűrtem ezekből, az az, hogy ezeket megfelelően kell kombinálni.
Oxidáció, főleg ha az hidrogén peroxid használatával van megtámogatva
"Permanganate dose of 1-8 mg/L was effective for algae &
cyanobacteria destruction (Fitzgerald, 1966). Permanganate at a dose of 1 mg/L achieved 95% removal of microcystin-LR in 30 minutes."
"UV advanced oxidation process with hydrogen peroxide resulted in 50% to 90% with hydrogen peroxide doses of 2 to 4 mg/L and UV intensities of 100 to 900 mJ/cm2 (WaterRF, 2010)."
Ózonizáció
"The most consistently efficient process for destruction of both ultra- and extracellular microcystins appears to be ozonation, which can rapidly achieve essentially complete destruction of microcystins, nodularin and anatoxin-a at low doses and contact times (Keijola et al., 1988)( Himberg et al., 1989)( Rositano and Nicholson, 1994)( Croll and Hart, 1996)( Rositano et al., 1996)(Hart et al., 1997). At low pH, an ozone dose of as little as 0.4 mg/L removed 97% of microcystin-LR (WaterRF, 2010)."
UVC szűrés
"UV radiation was capable of degrading both microcystin-LR and anatoxin-a, but at very high doses of about 20,000 mWs/cm2 (Croll and Hart, 1996), (WRc, 1996). UV alone or UV with hydrogen peroxide achieved about a 50% removal of microcystin-LR after 30 minutes (Rositano and Nicholson, 1994). UV advanced oxidation process with hydrogen peroxide resulted in 50% to 90% with hydrogen peroxide doses of 2 to 4 mg/L and UV intensities of 100 to 900 mJ/cm2 (WaterRF, 2010)."
Aktív szén
Powdered Activated Carbon (PAC) There is general agreement that to achieve high removal efficiencies, very high doses of PAC are required for toxin removal and that contact time is very important. A dose of 20 mg/L of PAC was able to achieve 90% removal of hepatotoxins following conventional treatment combined with pre-ozonation (Keijola et al., 1988).
Biológiai szűrés
Riverbank filtration has been demonstrated to be effective for algae removal, providing 4-log removal of algae cells (USEPA IESWTR). It is also effective for removal of cyanotoxins except during massive blooms (CK Schmidt et al, 2003).
Vízmozgatás
"The artificial mixing rate must be higher than the rate of vertical movement of the colonies of
cyanobacteria. Rates of colony movement depend on colony size and thus are somewhat variable (see section 2.3), but as a general rule, a mixing rate of 1 m h-1 is sufficient to prevent cyanobacterial blooms."
Vízcsere
Az elpusztult, lebomló cyanobaktérium sejtek által kibocsátott toxinok részben a fenti módszerekkel semlegesíthetők, de a nagyobb telepek hirtelen pusztulása során felszabaduló káros anyagokat (toxinok, ammónia) a leghatékonyabban hatékony vízcserékkel tudjuk visszaszorítani. Tehát ez is egy fontos eleme a harcnak.
"Flushing with water of low phosphorus concentrations can greatly reduce external inputs and will also accelerate recovery from internal loading by removing in-lake phosphorus which would otherwise be recycled for a number of growing seasons. If suitable water is available in sufficient quantity, flushing can be a very effective tool for reduction of cyanobacterial proliferation."
Algafogyasztók
Kérdés, mi eszi meg ezt a vackot, de ez is számításbe veendő.
Még egy érdekes olvasnivaló a témában, ami jóval kompaktabb:
The Impact of Water Treatment Plant Processes on Algae and Algal Toxins
https://public.health.oregon.gov/He...eatment/Documents/algae/Odell-WaterOnline.pdf
Ez főleg a
BGA által termelt toxinok hatástalanításáról szól, ipari méretekben.
