Integrating nutrient removal and solid management restricts the feasibility of algal biofuel generation via wastewater treatment

详细信息    查看全文

• 作者：E. Posadas^a ; ^b ; R. Muñ ; oz^b ; B. Guieysse^a ; ^{B.J.Guieysse@massey.ac.nz}
• 关键词：Biosolids ; High rate algal pond ; Nutrients reuse ; Wastewater treatment
• 刊名：Algal Research
• 出版年：2017
• 出版时间：March 2017
• 年：2017
• 卷：22
• 期：Complete
• 页码：39-46
• 全文大小：503 K
• 卷排序：22

文摘

While numerous studies have demonstrated the efficiency of secondary wastewater treatment (WWT) in high rate algae ponds (HRAPs), little consideration has been given to how the algal unit should be best integrated within a full treatment system complying with typical nutrient discharge standards. Using the case study of a 2000 person equivalent (P.E.), we first demonstrate that algal treatment is most efficiently used for combined carbon and nutrient removal because an HRAP designed for compliant N (or P) removal de facto provides free and environmentally-benign carbon removal. The large O2 excess capacity for aerobic carbon removal also suggests primary suspended solid removal is unlikely needed, although grit removal remains necessary. We then demonstrate combining algal cultivation with anaerobic digestion is not economic at small scale because it offers marginal energy savings (e.g. 10.7€ P.E.− 1 yr− 1) while incurring significant costs for digestate transport offsite (e.g. 32.5€ P.E.− 1 y− 1 at a distance of 50 km). Subsequent sensitivity analyses confirmed that while the potential of algae-to-biogas via WWT is limited (e.g. total cost of 38.2€ P.E.− 1 y− 1 in our base case), integrating the use of HRAPs with solar drying has the potential to provide a more economical and energy-efficient WWT alternative for nutrient removal and recovery (24.4€ P.E.− 1 y− 1).