[Purification Effect of Piggery Wastewater with Chlorella pyrenoidosa by Immobilized Biofilm-Attached Culture].

Piggery wastewater treatment with microalgae is a biological recycling technology. To evaluate the purification effect, this study investigated the treatment of piggery wastewater at different dilution ratios with Chlorella pyrenoidosa by attached cultivation and lipid production of algae cells and explored the tolerance of Chlorella pyrenoidosa to the piggery wastewater, which has high ammonia nitrogen. The piggery wastewater was diluted with purified water 1-, 2-, 5-, and 10-fold in culture media. The removal efficiencies of COD, ammonia nitrogen, total nitrogen, and total phosphorus and the enrichment effect of the heavy metals copper, zinc, and iron were measured. Meanwhile, we investigated the lipid production of Chlorella pyrenoidosa in variously diluted wastewater (1-, 2-, 5-, and 10-fold). It turned out that the purification effects of COD, ammonia nitrogen, total nitrogen, and total phosphorus were best when the piggery wastewater was diluted 5-fold, and the removal efficiencies were 86.8%, 94.1%, 85.2%, and 84.3%, respectively. Correspondingly, the lipid content was as high as 32.7%, and the removal efficiencies of the heavy metals copper, zinc, and iron were 72.9%, 70.0%, and 73.0%, respectively. The biomass productivity was 4.21 g·(m2·d)-1 at the end of the experiment. This research makes an effective connection between microalgae and piggery wastewater, which is difficult to purify deeply, and provides a theoretical basis for achieving algal biofuel production and decreasing the cost of wastewater treatment.

[Coupling of Hydrocarbon Accumulation and Cobalt Removal During Treatment of Cobalt Enriched Industrial Wastewater with Botryococcus braunii Biofilm Attached Cultivation].

Industrial wastewater pollution is an increasing problem. The wastewater infiltrated cobalt is a key to purify wastewater because it is seriously hazardous and hard to treat. Traditional management method of heavy metals in industrial wastewater is difficult to apply. To seek for "green ecological" feasible approaches of industrial wastewater treatment, this paper studied the effect of industrial wastewater containing cobalt on the growth and hydrocarbon accumulation of Botryococcus braunii SAG 807-1 with biofilm attached cultivation. The research results obtained were as follows:B.braunii with biofilm attached cultivation could treat industrial wastewater, and 4.5 mg·L-1 cobalt could accelerate the accumulation of hydrocarbon while having little influence on the growth of B.braunii, the ability of B.braunii with biofilm attached cultivation to remove Co2+ from industrial wastewater was 1473.9 µmol·g-1, which was much higher than the report of P. littoralis culture. Through the study in this paper, the theoretical basis for the coupling of production of green high energy fuel hydrocarbon and industrial wastewater treatment was established.

Growth and biochemical composition of filamentous microalgae Tribonema sp. as potential biofuel feedstock.

Filamentous oleaginous microalgae Tribonema minus have advantages in relatively easy harvesting and grazers resistance in mass cultivation due to its filaments in previous study. To evaluate whether the genus Tribonema is a valuable candidate for use in biofuel production, the morphology, growth, biochemical composition and fatty acid profile of six filamentous microalgae strains Tribonema sp. were investigated. All the strains are unbranched filament in single row of elongated cylinder, attaining 0.5-3 mm in length. The growth rates of tested strains were 0.35-0.42 g L(-1) d(-1). Generally, for all strains, decrease in protein content was followed by a slight increase in lipid and significant increase in carbohydrate in early phase, afterwards, lipid increased constantly inversely to decrease in carbohydrate content. After 15-day cultivation, total lipid contents of tested strains ranged from 38-61 %, of which TAG were the majority and palmitic acid (C16:0) and palmitoleic acid (C16:1) were the dominant components. The study confirmed that the genus Tribonema is the potential for biodiesel and bioethanol production upon culture time.