PUB - Publikationen an der Universität Bielefeld

Small-scale agriculture and industries in remote areas often lack the access to cost-effective wastewater (WW) treatment. One techno-economical solution could be the WW treatment by algal biofilm in the Algal Turf Scrubber (ATS). Here, a systematic, and year-round case study on the efficiency of algal biofilms in nutrient recovery from municipal and agricultural WW was carried out at exemplary places in Mid-Germany. The nutrient recovery of ATS biofilms were quantified by operating four pilot-scale ATS with municipal, pig, cattle, or biogas-effluent WW, for one year. The obtained data were used to evaluate the techno-economic feasibility of algal-based fertilizer production in ATS from WW. The cultivation data were analysed and employed for a techno-economical evaluation. The results show that macro- and micronutrients were recovered from all WWs in the algal biofilm. Technical data indicate a limited potential of agricultural WWs with high solid or nutrient load. Economic results found ATS biofilm production costs under current settings of 272 to 565 € kg−1 for the municipal and agricultural WW, respectively. Economic evaluation indicates competitive costs of 2.22 € kg−1 for fertilizer production in municipal WW at an ATS size of 1760 m2. SWOT analysis highlight a competitive ATS-based fertilizer with new market opportunities and conceivable solutions to urgent environmental challenges.