Study On Physiology And Of A Spirulina Platensis Isolated From Digested Piggery Wastewater And Cultivation With Pretreated Piggery Wastewater Professsional Disciplines: Environmental Science

Abundant of Digested Piggery Wastewater (DPW) came from the rapiddevelopment livestock and poultry. It would cause serious pollution without treated.The DPW contains low ratio of nitrogen/phosphorus and it is costly and diiffcult toremove. At the same time, DPW is abundant in nutrients of nitrogen, phosphorus,potassium and trace elements such as zinc, magnesium, and is also rich in amino acids,vitamins, growth hormone and other growth regulation substances. On the other hand,Spirulina is high values feed additives which is rich in protein and enhance immunityof animals. But high production cost limits the application in aquaculture. Thecultivation of Spirulina platensis using the DPW offers several advantages, includingan effective utilization of the nitrogen and phosphorus in the wastewater and a savingin the cost of spirulina culture medium.In present commonly used spirulina can’t grow in the DPW, so we isolated aspirulina platensis M in the storage tank of DPW which can grow fast. This studydiscusses the physiology of the local separation spirulina M and a preliminary studyon cultivation using preteated DPW. The major conclusions as follows:1)It was no significant difference in a growth cycle(8d) when bicarbonates content,nirtrogen concentration, phosphorus concentration and pH were respectively4_g-L1,30m_l"g-L,3mg-L1,8.5-9.0.2)Spirulina growth wasn’t affected when ammonia concentration less than60mg-L"1, but grow slowly ammonia concentration exceeded100mg-L"1, better thanother3spirulina(NS-90020、DLMMS2、DLMMS6). And nitrite is more toxic atthe concentration less th1an50mg-L".3)The growth promoter NAA couldnot faster the growth, but extended thelogarithmic growth of spirulina.4)Inoculated with logarithmic growth of Spirulina, it growed as fast as culture inZarrouk medium, and got a longer strains. Inoculated between2similar mediumcould shortend lag phase.5)It was no when DPW colour less than200degree; Spirulina growth slowed withthe increase of colour. The optimized inoculation was0.4and the most economicwas0.2in cultivation with DPW. Spirulina growth was no significant difference inin flrtstly8days’ culture with50%or20%dilution of DPW. And Spirulina grewslower in20%dilution of DPW later.6)In2batches cuture with lfasks, spirulina grew well in the medium with half DPWand Zarrouk at the firstly8days. 7)Raceway pond culture in lab-scale, dry weight of spirulina achieved1.0g-L"1, andaverage productivity exceed^1ed40g-m-d". Protein content or ash content met thestandard of feed spirulina GB/T17243-1998. But the quantity of mycete,escherichia coli were over the standard. The removal of TN or TP was very low,about10%-25%. Thus conversion efficiency of TN or TP was more than80%.8)Raceway pond culture in pilot-scale outside, We conducted6batches cultureexperiments, only3of which could reach the Spirulina harvest requirements(OD56o〉0.8). Meanwhile, the3successful batches achieved removal andconversion eiffciency of TN, TP were very low. At last, we analysis the cause offailure.