A Study On The Factors That Influence The Adhesion Of Ulva Prolifera Spores And The Flocculation Effects Of Ulva Prolifera Spores By Modified Clays

Reproduction modes of Ulva prolifera include sexual reproduction, asexualreproduction, and vegetation reproduction. Asexual reproduction includes sporereproduction and apomixis. Spore reproduction is an important way of Ulva proliferareproduction. Ulva prolifera spores can synthesis and release a kind of stickyglycoprotein. Spores will adhere rapidly when there was appropriate substratum andcan withstand unfavorable conditions. Under the appropriate nutrition andenvironmental conditions, a large number of adhered spores and other microscopicpropagules will germinate and grow rapidly. These microscopic propagules can be theprovenance of the green tides in the Yellow Sea. Therefore, studying how to limitUlva prolifera spores adhesion and germination is of great significance to preventUlva prolifera large area reproduction and prevent the green tides from the source.In this study, The impacts of environmental factors and substratums on adhesionof Ulva prolifera spores were investigated. Temperature, illumination intensity andsalinity were selected as the environmental factors, while nylon rope and bamboo asthe substratum for the adhesion trials. Then, the impacts of organosilicone antifoulingcoatings on the adhesion of Ulva prolifera spores were studied. Thepolydimethylsiloxane (PDMS), PDMS with the promoter sodium benzoate (NaB),PDMS with the promoter Sodium Pyrithione (NaPT) were selected as the antifoulingcoatings. In addition, Combined with the experience of harmful algal blooms removalby modified clays, the flocculation effects and germination rate of Ulva proliferaspores by used modified clays were studied. Modified clays include Aluminiumpolychlorid (PAC) modified clays from Wuxian, Jiangsu and PAC modified claysfrom Yicheng, Hubei. The results indicated that the adhesion rate of Ulva prolifera spores ontothese two substratums showed similar trend as environmental factors changed. Theoptimal temperature for adhesion of Ulva prolifera spores was25℃, the optimalsalinity was25, and the suitable illumination intensity range was2000~4000Lux.Because of the rougher surface, the adhesion rate of Ulva prolifera spores onto nylonrope was always higher than that of bamboo treatment under the same environmentalcondition. Adhesion rate of Ulva prolifera spores can be effectively reduced by usingorganosilicone antifouling coating PDMS. PDMS with NaB and PDMS with NaPTcan reduce the adhesion rate of Ulva prolifera spores more effectively than PDMS.Among them, the effect of PDMS with NaB is best, the adhesion rate of Ulvaprolifera spores is less than5%. PAC modified clays from Wuxian, Jiangsu and PACmodified clays from Yicheng, Hubei can remove the Ulva prolifera spores effectively.When the concentration of JSMC is0.5g/L, the removal rate of Ulva prolifera sporesis90%. When the concentration of HBMC is1.0g/L, the removal rate of Ulvaprolifera spores is91%. These two modified clays can inhibit the germination of Ulvaprolifera spores effectively when the concentration was1.0g/L.