## 2 Wastewater Treatment by Microalgae
### Agricultural Wastewater
#### 2.2.3 Microalgae Treatment of Agricultural Wastewater
Different wastewaters can also be combined, such as piggery farm wastewater and winery industry wastewater, to be treated by _Chlorella_ sp. MM3 strain from the soil [70]. At the ratio 20:80 of piggery and winery wastewaters, _Chlorella_ sp. MM3 removed 89.36% for the TN removal efficiency and 56.56% for the TP removal efficiency, and achieved a high lipid yield of about 51% [70]. Recently, 2.5% of cattle wastewater was diluted with domestic wastewater as a substitute for freshwater to be treated by _Chlorella thermophila_ (MF179624), isolated from sewage wastewater [71]. They reported that _Chlorella thermophila_ grew well (2.17 g L\({}^{-1}\) of biomass) in 2.5% of cattle wastewater, compared to domestic wastewater (1.22 g L\({}^{-1}\) of biomass) and bold basal medium (1.24 g L\({}^{-1}\) of biomass), and gave interesting compounds such as lipids (18.27%), carbohydrates (29.39%) and proteins (44.91%) [71]. _Chlorella thermophila_ had the highest removal rates of ammonium (53.74 mg L\({}^{-1}\) d\({}^{-1}\)), nitrate (6.96 mg L\({}^{-1}\) d\({}^{-1}\)) and more than 99% of phosphorus [71]. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Algae Used** & **Wastewar Type** & **Conditions of Culture** & **Nutrient Concentration** & **Average Nutrient Removal Rate** & **References** \\ \hline _Actidesesum elegans_ & Piggery & 25\({}^{\circ}\)C for 138 h & COD: 11,100 mg L\({}^{-1}\); TN: & TN: 175 mg g\({}^{-1}\) d\({}^{  
\begin{table}
\begin{tabular}{c c c c c c} \hline
**Algae Used** & **Wastewater Type** & **Conditions of Culture** & **Nutrient Concentration** & **Average Nutrient Removal Rate** & **References** \\ \hline \hline \multirow{3}{*}{_Chlorella sp. MM3_} & Mixed piggery and winery (20\% C) & 23 °C & TN: 284 mg L\({}^{-1}\); TP: 11 mg L\({}^{-1}\) & TN: 89.36\%; TP: 56.56\% & [70] \\  & (20\%0 ratio) & & pH: 6.11, NH\({}_{4}\)N: 22.38 mg L\({}^{-1}\); & NH\({}_{4}\)N: 83.74 mg L\({}^{-1}\); & \\  & & 25 °C; 100 \(\rm{\mu E}\) m\({}^{-2}\) s\({}^{-1}\); aeration & NO\({}_{3}\)-N: 304 mg L\({}^{-1}\); FO\({}_{4}\)P; & NO\({}_{3}\)-N: 6.96 mg L\({}^{-1}\); \({}_{1}\)O\({}_{4}\)P; & [71] \\  & & 0.5\%VN & 760 mg L\({}^{-1}\) & more than 99\% \\  & & 21 °C; 212 light; dark; & 100.193 mg L\({}^{-1}\); TN: & \\  & & & First stage: add prepolution of & 163.40 mg L\({}^{-1}\); TP: 147.0 mg L\({}^{-1}\) & COD: 99\%; TN: 91\% PT: 85\% & [62] \\  & & & First stage: add prepolution of & & \\  & & & wastewater; Second stage: batch & & \\  & & & conditions: 25-27 °C, continuous & & \\  & & & illuminations 400 \(\rm{\mu E}\) m\({}^{-2}\) s\({}^{-1}\); & COD: 2185–7313 mg L\({}^{-1}\) & COD (first step): 80\%; COD & \\  & & & Continuous process: 25 °C, continuous & & (second step): more than 88\% & [80] \\  & & & continuous illumination & & \\  & & & 440 \(\rm{\mu E}\) m\({}^{-2}\) s\({}^{-1}\) & PH: 5.5–6.0; COD: & & \\  & & & 4924-500.7 mg L\({}^{-1}\); & COD: 8.47 mg L\({}^{-1}\); & \\  & & & & 17.425–545 mg L\({}^{-1}\); TP: & TN: 16.84 mg L\({}^{-1}\); & [57] \\  & & & 31.8–426 mg L\({}^{-1}\); TP: & TN: 14.00 mg L\({}^{-1}\) d\({}^{-1}\) & \\ Desundessums sp.