Comparative evaluation of piggery wastewater treatment in algal-bacterial photobioreactors under indoor and outdoor conditions

Abstract

This work evaluated the performance of four open algal-bacterial photobioreactors operated at ≈26days of hydraulic retention time during the treatment of 10 (×10) and 20 (×20) times diluted piggery wastewater (PWW) under indoor (I) and outdoor (O) conditions for four months. The removal efficiencies (REs) of organic matter, nutrients and zinc from PWW, along with the dynamics of biomass concentration and structure of algal-bacterial population were assessed. The highest TOC-RE, TP-RE and Zn-RE (94±1%, 100% and 83±2%, respectively) were achieved indoors in ×10 PWW, while the highest TN-RE (72±8%) was recorded outdoors in ×10 PWW. Chlorella vulgaris was the dominant species regardless of the ambient conditions and PWW dilution. Finally, DGGE-sequencing of the bacterial community revealed the occurrence of four phyla, Proteobacteria being the dominant phylum with 15 out of the 23 most intense bands.

A systematic comparison of the potential of microalgae-bacteria and purple phototrophic bacteria consortia for the treatment of piggery wastewater

“…These higher IC 305 concentrations recorded in the effluent of both PBRs compared to the IC concentration 306 in the piggery wastewater evidenced the accumulation of inorganic carbon mediated by 307 the active microbial TOC oxidation. This finding was in agreement with previous 308 observations in HRAPs treating PWW (García et al, 2017b). Overall, the higher IC-REs 309 during the treatment of PWW in PBR-AB were likely mediated by the higher biomass 310 concentrations and the oxygenic nature of the photosynthesis prevailing in PBR-AB 311 (Table 1).…”

The effect of the algal microbiome on industrial production of microalgae

“…Although next-generation sequencing (NGS) has led to an explosion of microbial diversity studies in microbial ecology research, only a limited number of studies have been published on NGS-based microbiota analysis in the context of microalgal production systems. In fact, most knowledge of alga-bacteria communities in applied settings come from wastewater treatment studies (Garc ıa et al, 2017;Sun et al, 2018;Yang et al, 2018). However, those systems are too different to microalgae production systems due to the presence of high concentrations of organic and inorganic material to expect a large overlap in microbial communities in wastewater treatment systems and algae production facilities.…”

Lab‐scale testing of operation parameters for algae based treatment of piggery wastewater

“…7 Moreover, microalgae produce oxygen available for bacteria, thus reducing or eliminating the need for aeration and improving the interaction between algae and ammonia-oxidizing and nitrite-oxidizing bacteria. 8 According to the intensive research conducted on the use of microalgae-bacteria consortia to treat piggery wastewater (PWW) in the last few years, pretreatment or dilution of PWW seems to be needed for adequate microalgal growth, 9 owing to its intense color, limited light penetration 10 and high ammoniacal N concentration, which can be toxic for microalgae. 11 Owing to the limitation of fresh water supply and potential problems with the management of a larger volume of water, the dilution of PWW for microalgae growth cannot be considered as a viable option.…”