Ammonia Bioremediation from Aquaculture Wastewater Effluents Using Arthrospira platensis NIOF17/003: Impact of Biodiesel Residue and Potential of Ammonia-Loaded Biomass as Rotifer Feed.

The present work evaluated the capability of Arthrospira platensis complete biomass (ACDW) and the lipid-free biomass (LFB) to remove ammonium ions (NH4+) from aquaculture wastewater discharge. Under controlled conditions in flasks filled with 100 mL of distilled water (synthetic aqueous solution), a batch process ion-exchange was conducted by changing the main parameters including contact times (15, 30, 45, 60, 120, and 180 min), initial ammonium ion concentrations (10, 20, 30, 40, 50, and 100 mg·L-1), and initial pH levels (2, 4, 6, 8, and 10) at various dosages of ACDW and LFB as adsorbents (0.02, 0.04, 0.06, 0.08, and 0.1 g). After lab optimization, ammonia removal from real aquaculture wastewater was also examined. The removal of ammonium using ACDW and LFB in the synthetic aqueous solution (64.24% and 89.68%, respectively) was higher than that of the real aquaculture effluents (25.70% and 37.80%, respectively). The data of IR and Raman spectroscopy confirmed the existence of various functional groups in the biomass of ACDW and LFB. The adsorption equilibrium isotherms were estimated using Freundlich, Langmuir, and Halsey models, providing an initial description of the ammonia elimination capacity of A. platensis. The experimental kinetic study was suitably fit by a pseudo-second-order equation. On the other hand, as a result of the treatment of real aquaculture wastewater (RAW) using LFB and ACDW, the bacterial counts of the LFB, ACDW, ACDW-RAW, and RAW groups were high (higher than 300 CFU), while the LFB-RAW group showed lower than 100 CFU. The current study is the first work reporting the potential of ammonia-loaded microalgae biomass as a feed source for the rotifer (Brachionus plicatilis). In general, our findings concluded that B. plicatilis was sensitive to A. platensis biomass loaded with ammonia concentrations. Overall, the results in this work showed that the biomass of A. platensis is a promising candidate for removing ammonia from aquaculture wastewater.

Potential Applications of Arthrospira platensis Lipid-Free Biomass in Bioremediation of Organic Dye from Industrial Textile Effluents and Its Influence on Marine Rotifer (Brachionus plicatilis).

Arthrospira platensis is one of the most important cultured microalgal species in the world. Arthrospira complete dry biomass (ACDB) has been reported as an interesting feedstock for many industries, including biodiesel production. The A. platensis by-product of biodiesel production (lipid-free biomass; LFB) is a source of proteins, functional molecules, and carbohydrates, and can also be reused in several applications. The current study investigated the efficiency of ACDB and LFB in bioremediation of dye (Ismate violet 2R, IV2R) from textile effluents. In addition, the potential of ACDB and LFB loaded by IV2R as a feed for Rotifer, Brachionus plicatilis, was examined. The surface of the adsorbents was characterized by SEM, FTIR, and Raman analysis to understand the adsorption mechanism. The batch sorption method was examined as a function of adsorbent dose (0.02-0.01 g L-1), solution initial concentration (10-100 mg L-1), pH (2-10), and contact time (15-180 min). The kinetic studies and adsorption isotherm models (Freundlich, Langmuir, Tempkin, and Halsey) were used to describe the interaction between dye and adsorbents. The results concluded that the adsorption process increased with increasing ACDB and LFB dose, contact time (120 min), initial IV2R concentration (10 mg L-1), and acidity pH (2 and 6, respectively). For the elimination of industrial textile wastewater, the ACDB and LFB sorbents have good elimination ability of a dye solution by 75.7% and 61.11%, respectively. The kinetic interaction between dye and adsorbents fitted well to Langmuir, Freundlish, and Halsey models for LFB, and Langmuir for ACDB at optimum conditions with R2 > 0.9. In addition, based on the bioassay study, the ACDB and LFB loaded by IV2R up to 0.02 g L-1 may be used as feed for the marine Rotifer B. plicatilis.

Community composition, abundance and biomass of tintinnids (Ciliata: Protozoa) in the Western Harbour, south-eastern Mediterranean Sea, Egypt.

Seasonal variations in species composition, abundance and biomass of tintinnids (Protozoa: Ciliata) were investigated in the Western Harbour, seasonally during 2012. There were remarkable seasonal variations in environmental parameters, phytoplankton concentrations and abundance and biomass of tintinnids: highest in spring and lowest in autumn. Annual average abundance and biomass of tintinnids were 8.435 ind. l(-1) and 3.725 µg C l(-1), respectively. A total of 29 species of tintinnids belonging to 11 genera was identified. Of which, Tintinnopsis was the most abundant genus in terms of number of species (9), but Favella was the best quantitatively (89% of the total tintinnids). The overall mean abundance and biomass were highest (mean 24.415 ind. l(-1) and 10.355 µg C l(-1), respectively) during spring than the remaining seasons. Due to significant positive relationship between the total biomass of tintinnids and phytoplankton concentrations, food supply is not a problem for tintinnids harbouring in the Western Harbour. Hence, predation loss by meso- and macrozooplankton might be the possible reasons for the estimated low biomass of tintinnids in the present study. Some of the seasonal environmental factors as water salinity, nitrite, dissolved oxygen and pH values exert an influence on the species composition, abundance and biomass of tintinnids.

Cultivation of Arthrospira (Spirulina) platensis using confectionary wastes for aquaculture feeding.

The microalga biomass production from confectionary effluent is a possible solution for the urgent need for a live food in aquaculture. Arthrospira (Spirulina) platensis was the dominant alga in effluent of "Biscomisr a confectionary factory", in Alexandria-Egypt. Therefore, it was isolated from the effluent samples and used throughout the study. The cyanobacterium, A. platensis was grown on the effluent using 22 Central Composite Design (22 CCD). This work addresses the best effluent dilution (WC, %) as well as sodium bicarbonate concentration (SBC) on the alga growth and biochemical composition. Total protein, carbohydrate, lipid contents and fatty acid profiles of the produced algal biomass were highly improved. The statistical analyses suggested that the main effect of (WC, %) is significant negative influences on the algal contents of proteins, lipids and carbohydrates (p > 0.01). Although it had a significant positive influence on chlorophyll (p > 0.01), no significant effect on algal ß carotenes (p > 0.05) had been reported. The inter action effect of SBC together with WC, % exerted a significant negative influence on the algal proteins (p > 0.01) and no significant effect on the other responses (p > 0.05). The produced alga biomass was used for feeding the rotifer, Brachionus plicatilis for further application in aquaculture. Growth rate, reproductive rate and fecundity attributes, fatty acid content of B. plicatilis were amended. The Pearson correlation test indicated that ß carotenes displayed a highly positive significant correlation with the growth rate of B. plicatilis (r = 0.733, p < 0.01) and the carbohydrates showed significant positive correlations with Egg % (r = 0.657, p < 0.05).