Nutrients and water play an important role in microalgae cultivation. Using wastewater as a culture medium is a promising alternative to recycle nutrients and water, and for further developing microalgae-based products. In the present study, two species of microalgae, Chlorella sp. (high ammonia nitrogen tolerance) and Spirulina platensis (S. platensis, high growth rate), were cultured by using poultry wastewater through a two-stage cultivation system for algal biomass production. Ultrafiltration (UF) or centrifuge was used to harvest Chlorella sp. from the first cultivation stage and to recycle culture medium for S. platensis growth in the second cultivation stage. Results showed the two-stage cultivation system produced high microalgae biomass including 0.39 g·L–1Chlorella sp. and 3.45 g·L–1S. platensis in the first-stage and second-stage, respectively. In addition, the removal efficiencies of NH4+ reached 19% and almost 100% in the first and the second stage, respectively. Total phosphorus (TP) removal reached 17% and 83%, and total organic carbon (TOC) removal reached 55% and 72% in the first and the second stage, respectively. UF and centrifuge can recycle 96.8% and 100% water, respectively. This study provides a new method for the combined of pure microalgae cultivation and wastewater treatment with culture medium recycling.
Many studies on methane emissions from animal manure have revealed that animal manure is a major source of methane emissions
to the atmosphere that can have negative consequences for people, animals and environment. In general, the release of methane can
be influenced by the type of feed taken by animals, temperature, manure characteristics and so on. This study aimed at quantifying
and comparing methane release from dairy manure with di erent piling treatments. Four treatments were designed including manure
piling height 30, 45, 60 cm and adding 6 cm manure every day until the piling height was 60 cm. Static chamber method and gas
chromatography were adopted to measure the methane emissions from April to June in 2009. Methane emission rates of all four
manure treatments were low in the first week and then increased sharply until reaching the peak values. Subsequently, all the methane
emission rates decreased and fluctuated within the steady range till the end of the experiment. Wilcoxon nonparametric tests analysis
indicated that methane emission rate was greatly influenced by manure piling height and manner. There were no significant relationships
between methane emission rates and the temperatures of ambience and heap. However, regression analysis showed that the quadratic
equations were found between emission rates of all treatments and the gas temperature in the barrels. 相似文献
Accurate monitoring of the atmospheric environment and its evolution are important for understanding the sources, chemical mechanisms, and transport processes of air pollution and carbon emissions in China, and for regulatory and control purposes. This study gives an overview of atmospheric environment monitoring technology and equipment in China and summarizes the major achievements obtained in recent years. China has made great progress in the development of atmospheric environment monitoring technology and equipment with decades of effort. The manufacturing level of atmospheric environment monitoring equipment and the quality of products have steadily improved, and a technical & production system that can meet the requirements of routine monitoring activities has been initiated. It is expected that domestic atmospheric environment monitoring technology and equipment will be able to meet future demands for routine monitoring activities in China and provide scientific assistance for addressing air pollution problems. 相似文献
China has established the largest clean coal-fired power generation system in the world by accomplishing the technological transformation of coal-fired power plants(CFPPs) to achieve ultra-low emission. The potential for further particulate matter(PM) emission reduction to achieve near-zero emission for CFPPs has become a hotspot issue. In this study,PM emission from some ultra-low emission CFPPs adopting advanced air pollutant control technologies in China was reviewed. The results revealed tha... 相似文献