Anaerobic digestion is a suitable method for treating organic wastes and generating biogas. This biogas contains significant amount of CO₂ and some other contaminants. The coupling of wastewater treatment with biogas purification using saline microalgae could effectively upgrade biogas (through photosynthetic CO₂ fixation) and concurrently remove nutrients from the effluent, while producing valuable algal biomass. In this context, Tetraselmis suecica biomass production with the use of an impurity (CO₂) in biogas to supply carbon, and nutrients (nitrogen and phosphorus) from anaerobically-digested piggery effluent (ADPE) was investigated at four operating pH set points (6.5, 7.5, 8.5 and 9.5). Results showed that pH 7.5 produced the optimum conditions for T. suecica growth and biogas-based CO₂ removal, with the maximum biomass (59.8 mg L⁻¹ d⁻¹), lipid (25 mg L⁻¹ d⁻¹) and carbohydrate (6.5 mg L-1 d-1) productivities. Under this condition, CO₂, total nitrogen and phosphorus removal efficiencies were 94.7%, 96% and 72%, respectively. Furthermore, the results showed no inhibitory effect of dissolved CH₄ on the growth of T. suecica at pH 7.5, suggesting the technical feasibility of harnessing marine T. suecica for simultaneous nutrients removal from wastewaters, biogas upgrading, and production of energy-rich algal biomass. This process clearly harnesses anaerobically-digested piggery effluent not only as an asset but also uses an impurity (CO₂) in biogas to produce valuable algal biomass.

厌氧消化是处理有机废物和产生沼气的合适方法。这种沼气中含有大量的CO ₂和一些其他污染物。废水处理与使用盐水微藻进行沼气净化的结合可以有效地提升沼气（通过光合作用CO ₂固定），并同时从废水中去除营养物，同时产生有价值的藻类生物质。在这种情况下，扁藻suecica生物量产生与使用中的杂质的（CO ₂在四个操作pH设定点（6.5、7.5、8.5和9.5）下研究了从沼气中提供碳和来自厌氧消化的猪排泄物（ADPE）的养分（氮和磷）。结果表明，pH 7.5产生了最佳的蔗糖生长和基于沼气的CO ₂去除条件，其中最大的生物量（59.8 mg L ^-1  d ^-1），脂质（25 mg L ^-1  d ^-1）和碳水化合物（6.5 mg L-1 d-1）生产率。在此条件下，CO ₂，总氮和磷的去除效率分别为94.7％，96％和72％。此外，结果表明，溶解的CH ₄对木薯的生长没有抑制作用。T. suecica的pH值为7.5，这表明利用海洋T. suecica来同时去除废水中的养分，沼气升级和生产高能藻类生物质的技术可行性。该过程显然将厌氧消化的猪场废水不仅用作资产，而且还利用沼气中的杂质（CO ₂）产生有价值的藻类生物质。