The effects of salinity on the growth and biochemical properties of Chlamydomonas mexicana GU732420 cultivated in municipal wastewater.

A freshwater microalga Chlamydomonas mexicana was grown on municipal wastewater with different levels of salinity up to 400 mmol/L NaCl, and the biochemical properties were characterized after 10 days of cultivation. C. mexicana showed the higher specific growth rates for 100 and 200mmol/L NaCl. Nitrogen was completely removed within 10 days as a result of algal growth promoted by the addition of 200-400 mmol/L NaCl. Phosphorus removal increased from 77-84% as the concentration of NaCI increased from 100 to 400 mmol/L. The highest removal of total inorganic carbon (66%) was obtained with the addition of 200 mmol/L NaCl. The lipid content increased from 17% to 38% as the concentration of NaCl increased from 0 to 400mmol/L. The total fatty acid content and glycerol yield of C. mexicana increased 1.8- and 4-fold in wastewater amended with NaCl, respectively. Fatty acids accumulated in the algal biomass were mainly composed of palmitic (27-29%), y-linolenic (27-30%), and linolelaidic acids (16-18%). The optimal condition for fatty acids production in C. mexicana was observed when the municipal wastewater was amended with 100-200 mmol/L NaCl with a simultaneous removal of nutrients.

Removal of nitrate and ammonium ions from livestock wastewater by hybrid systems composed of zero-valent iron and adsorbents.

The feasibility of hybrid systems for simultaneous removal of nitrate (NO3-) and ammonium ions (NH4+) from livestock wastewater was examined in batch experiments. As a part of efforts to remove nitrate and ammonium simultaneously, Fe0 and adsorbents including coconut-based granular activated carbon (GAC), sepiolite and filtralite were used. Various parameters such as adsorbent dosages and temperature were studied. Removal of NO3- increased with increase in temperature. Maximum NO3- removal (85.3%) was observed for the Fe0-filtralite hybrid system at 45 degrees C for a 24 h reaction time. Increase in GAC and sepiolite dosages had significant (P < 0.01) effect on the NH4+ removal efficiency, which was primarily due to the net negative surface charge of the adsorbents. The efficiency of hybrid systems for the removal of NO3- was in the order of filtralite > sepiolite > GAC, and the order of the removal of NH4+ was GAC > sepiolite > filtralite. The results of the present study suggest that the use of hybrid systems could be a promising innovative technology for achieving simultaneous removal of NO3- and NH4 from livestock wastewater.