Screening Suitable Materials For Algal Biofilm Growth And Its Application On Nitrogen And Phosphorus In Wastewater Treatment

Algae biofilm technology is a biological nutrient removal technology that can absorb water through their nitrogen and phosphorus assimilation without expensive harvest operations.The new technology has improved the efficiency of biomass collection and reduce the cost of collection effectively. Currently, researchs on biofilm have been a hot topic.This work aimed to develop an algal biofilm cultivation system that can be widely adopted by microalgal producers for easy biomass harvest. The main findings are as follows:(1) Screening suitable materials for algal biofilm growthA total of 14 materials were tested for their capability of supporting attached algal growth, including cotton, polyester, hemp, cotton linen, velvet, plush, silk, organza, gauze,coral velvet, plastic wrap and sealing film. It was found that the best cell attachment occurred in plush, while gauze and cotton, cotton material was degraded due to poor durability during the experiment. SEM microscopy results also confirmed this phenomenon. Plush not only supported excellent attached algal growth, but also showed good durability with low cost. The highest yield was 93.064 g/m2. Comparative study of the plush, coral cashmere double-sided, double-layer velvet(stuffed prepared) three biofilm carrier material effect, found that the two velvet showed good reproducibility, and hung higher film yield, up to 129.664 g / m2.Through the analysis of SEM and FT-TR, The results showed that: with respect to natural materials, synthetic materials adhere better, higher biofilm production, material life cycle longer lasting and better.(2) Screening suitable conditionsTo ensure optimum utilization of solar energy, this experiment selected 15850 lux as the most suitable light intensity. Under optimal lighting conditions screened films pitch 4cm. The final working condition is : 15850 lux, 4cm, 20 r/min.(3) Sewage treatment experimentTwo experiments found that the average removal rate of nitrogen was 95.12%, COD removal rate was 89.84%, the average removal rate of phosphorus,was 65.89%.Collectively, the research shows that the system is an efficient algal culture system for easy biomass harvest with enhanced biomass productivity.