A Mini Review on Microalgae Biomass Production: Recent Progress in Cultivation Systems

Single-celled photosynthetic microscopic algae (microalgae) have numerous significances for human wellbeing. From medicine to fuel industry these tiny organisms have tremendous potentials and in future they would be game changer to mitigate global warming and environmental pollutions. The current production cost is a matter of consideration during its applications. Scientists all over the world are trying to reduce the production costs as well as to develop new or improve the existing culturing methodologies and techniques. Open pond and closed pond (PBRs) culturing system are two most prominent ways to culture microalgae. Open pond culturing techniques for microalgae have several advantages over closed pond system such as low operational costs and easy to make. However, the main drawback of this system is contamination by other microorganisms, which is possible to control in closed pond system. Among the many types of PBRs systems, the advanced tubular PBRs presently considered as more useful than open pond culture system. To meet the minimum production costs, more research is needed on both the culturing systems.

Land-Use Modes of the Dike–Pond System in the Pearl River Delta of China and Implications for Rural Revitalization

Rural revitalization is a global problem. The measures should be adjusted to local conditions to make targeted efforts. Natural and socioeconomic resource factors should be considered in rural revitalization. Therefore, this study focuses on the dike–pond system, which is an important traditional agricultural cultural heritage in the Pearl River Delta of China, to illustrate the importance of identifying the utilization mode of a certain land-use type in village integrated with socioeconomic factors to promote rural revitalization. The study used principal component analysis (PCA) and the variance inflation factor (VIF) to identify the main factors influencing the land-use modes of the dike–pond systems, systematic cluster analysis to identify the modes, and interpretive structural modeling to clarify the influence relationships and structures of the factors. We found that the seven modes reflected the different characteristics, organizational structures, and interaction relationships of the factors. There were significant differences in the ecological processes between the seven modes. More detailed village planning should be performed. Strengthening the economic affordability of the operator should be regarded as important in policy guidance and support measures. Agricultural support measures need to be adjusted to different land-use type systems, and localized resources should be revitalized by the theory of “human–earth–sphere”.

Economic and Environmental Assessment of Two Different Rain Water Harvesting Systems for Agriculture

Increasing aridity and subsequent water scarcity are currently among the major problems of agriculture. Rainwater harvesting could represent a way to tackle this issue, and, as a consequence, scientific research has been more and more focused on such topic. On the other hand, few scientific studies related to economic and environmental assessment of rainwater harvesting systems in agriculture are available. The present study carried out an economic and environmental analysis of two different systems for rainwater harvesting: a typical pond and an innovative flexible water storage system (FWSS). The environmental and economic performance of the systems was compared using the Life Cycle Assessment (LCA) and Life Cycle Costing (LCC) methodologies, referring to a functional unit (FU) of 1 m3 of storable water. The FWSS showed better environmental end economic performance than the pond system, resulting with both lower environmental impacts (17.04 g per m3 CO2vs 28.2 g per m3 CO2) and lower costs (16.94 € per m3vs 20.41 € per m3). Moreover, the pond system was more impactful than the FWSS for all the 17 categories investigated. Therefore, the FWSS can be a suitable solution for water harvesting in agriculture sector, showing interesting features for farmers.