Recent research has demonstrated the potential of using filamentous fungi to form pellets with microalgae (biopellets), in order to facilitate harvesting of microalgae from water following ...algae-based treatment of wastewater. In parallel, there is a need to develop techniques for removing organic pollutants such as pesticides and pharmaceuticals from wastewater. In experiments using the microalga
Chlorella vulgaris
, the filamentous fungus
Aspergillus niger
and biopellets composed of these microorganisms, this study investigated whether fungal-assisted algal harvesting can also remove pesticides from contaminated water. A mixture of 38 pesticides was tested and the concentrations of 17 of these were found to be reduced significantly in the biopellet treatment, compared with the control. After harvesting, the concentration of total pesticides in the algal treatment did not differ significantly from that in the control. However, in the fungal treatment and biopellet treatment, the concentration was significantly lower (59.6 ± 2.0 µg/L and 56.1 ± 2.8 µg/L, respectively) than in the control (66.6 ± 1.0 µg/L). Thus fungal-assisted algal harvesting through biopellet formation can also provide scope for removing organic pollutants from wastewater, with removal mainly being performed by the fungus.
The beer-brewing process produces high amounts of nutrient-rich wastewater, and the increasing number of microbreweries worldwide has created a need for innovative solutions to deal with this waste. ...In the present study, fungal biomass production and the removal of organic carbon, phosphorus and nitrogen from synthetic brewery wastewater were studied. Different filamentous fungi with a record of safe use were screened for growth, and
Trametes versicolor
,
Pleurotus ostreatus
and
Trichoderma harzianum
were selected for further work. The highest biomass production, 1.78 ± 0.31 g L
−1
of dry weight, was observed when
P. ostreatus
was used for the treatment, while
T. harzianum
demonstrated the best capability for removing nutrients. The maximum reduction of chemical oxygen demand, 89% of the initial value, was observed with this species. In the removal of total nitrogen and phosphorus, no significant difference was observed between the species, while removal of ammonium varied between the strains. The maximum reduction of ammonium, 66.1% of the initial value, was also found in the
T. harzianum
treatment. It can be concluded that all treatments provided significant reductions in all water-quality parameters after 3 days of growth and that the utilisation of filamentous fungi to treat brewery wastewater, linked to a deliberate strategy to use the biomass produced, has future potential in a bio-based society.
Wetlands have been successfully implemented as water purification systems for removal of plant nutrients and can play a significant role in nutrient recycling, depending on use of the harvested ...biomass. In a constructed wetland in southern Sweden examined in this study, assimilation of plant nutrients in wetland biomass corresponded to 234 kg/ha nitrogen, 22.8 kg/ha phosphorus, and 158 kg/ha potassium in the study year (2016). The harvested biomass, composed exclusively of common reed, was evaluated as a substrate for production of oyster mushrooms, one of the most widely produced edible mushrooms in the world. The biological efficiency of the substrate was 138 ± 10%, corresponding to production of 1.4 kg mushrooms (fresh weight) based on 1 kg reed (dry weight). The fruiting bodies had high quality, with total protein concentration 18.3 ± 2.8% and very low levels of contaminating heavy metals. Thus, nutrient assimilation in wetland biomass not only decreases the risk of eutrophication in recipient waters, but can be utilized for direct production of high-quality food. The biomass remaining after mushroom production, composed of mycelium and partly degraded wetland biomass, has potential for use in ruminant feed, i.e., as roughage.
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•Reed was harvested from a constructed wetland in southern Sweden.•Reed biomass was used as a substrate for production of oyster mushrooms.•The biomass supported high production of high-quality fruiting bodies.•Nutrients assimilated in reed biomass can be used for direct production of food.
Nutrient-rich liquid waste streams generated during the beer brewing were treated by submerged fungal growth. Among five filamentous fungal strains tested,
Pleurotus ostreatus
and
Trichoderma ...harzianum
were selected for treatment of run-off from spent grain and hot trub, respectively. In both waste streams, nitrogen was well removed by fungal treatment, with a maximum reduction of 91.5 ± 0.5% of total nitrogen in run-off from spent grain treated with
P. ostreatus
and 77.0 ± 3.1% in hot trub treated with
T. harzianum
. Removal of phosphorus was considerably lower, with maximum removal of total phosphorus of 30.8 ± 11.1% for the
P. ostreatus
treatment and 16.6 ± 7.8% for the
T. harzianum
treatment. Considering the high concentration of phosphorus in the waste sources (320–600 mg L
−1
), additional techniques for its removal are needed. In the
P. ostreatus
treatment, a total amount of 13.2 ± 2.2 g L
−1
dwt of biomass with a protein concentration of 11.6 ± 2.1% was produced.
Removal of cadmium (Cd) present at low levels (1 µg L
−1
) in water was investigated using three different microorganism treatments: the microalga Chlorella vulgaris, the fungus Aspergillus niger, ...and for the first time biopellets composed of C. vulgaris and A. niger. After 5 days, all microorganism treatments resulted in significantly lower Cd concentrations compared with the control. Biopellets treatment resulted in significantly lower pH values than other microorganism treatments, indicating that the biopellets should be investigated further for their water treatment capacity, since pH is a factor affecting the fate of numerous pollutants in water. Use of biopellets as a method to simplify harvesting of microalgae from water is also suggested.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The effect of the microalgae Chlorella vulgaris on a wide range of different pesticides in water was studied. Treatments included short-term exposure (1 h) to living and dead microalgal biomass and ...long-term exposure (4 days) to actively growing microalgae. The initial pesticide concentration was 63.5 ± 3.9 µg L ⁻¹. There was no significant overall reduction of pesticides after short-term exposure. A significant reduction of the total amount of pesticides was achieved after the long-term exposure to growing microalgae (final concentration 29.7 ± 1.0 µg L ⁻¹) compared with the long-term control (37.0 ± 1.2 µg L ⁻¹). The concentrations of 10 pesticides out of 38 tested were significantly lowered in the long-term algal treatment. A high impact of abiotic factors such as sunlight and aeration for pesticide reduction was observed when the initial control (63.5 ± 3.9 µg L ⁻¹) and the long-term control (37.0 ± 1.2 µg L ⁻¹) were compared. The results suggest that water treatment using microalgae, natural inhabitants of polluted surface waters, could be further explored not only for removal of inorganic nutrients but also for removal of organic pollutants in water.
Removal of seven pharmaceuticals (acetaminophen, carbamazepine, diclofenac, metoprolol, naproxen, ranitidine and sulfamethoxazole) from water was investigated using three different microbial ...treatments with: (1) the microalga Chlorella vulgaris, (2) the fungus Aspergillus niger and (3) biopellets composed of both microorganisms. The three-day experiment was performed under laboratory conditions and pharmaceuticals were spiked at the environmentally relevant concentration of 10μgL−1. The biopellets and fungal treatments resulted in significantly lower ranitidine concentration compared with the initial value. Also, treatment with biopellets resulted in significantly lower final ranitidine concentrations compared to those found after control and microalgal treatments. Low removal rates were obtained for other substances, possibly because the amount of microbial biomass used was 16–500-fold lower than that normally used in activated sludge processes in wastewater treatments plants. Thus, the pharmaceutical removal potential, elimination potential and performance of biopellets should be further investigated at higher biomass concentrations.
•Influence of tracer data analysis method on wetland hydraulics was investigated.•Influence of method was higher for dispersion (N) than for effective volume (e).•Method influenced estimation of ...wetland pollutant removal rate least of all.•Published articles may contain overestimated e values and removal rate.•Unrealistic e values can be avoided by proper RTD truncation.
Hydraulic tracer studies are frequently used to estimate wetland residence time distributions (RTDs) and ultimately pollutant removal. However, there is no consensus on how to analyse these data. We set out to (i) review the different methods used and (ii) use simulations to explore how the data analysis method influences the quantification of wetland hydraulics and pollutant removal. The results showed that the method influences the water dispersion (N) most strongly and the removal least strongly. The influence increased with decreasing effective volume ratio (e) and N, indicating a greater effect of the method in wetlands with low effective volume and high dispersion. The method of moments with RTD truncation at 3 times the theoretical residence time (tn) and tracer background concentration produced the most dissimilar parameters. The most similar parameters values were those for gamma modelling and the method of moments with RTD truncation at tracer background concentration. For correct removal estimates, e was more important than N. However, the results from the literature review and simulations indicated that previously published articles may contain overestimated e and underestimated N values as a result of frequent RTD truncations at 3tn when using the method of moments. As a result, the removal rates may also be overestimated by as much as 14% compared to other truncation methods or modelling. Thus, it is recommended that wetland hydraulic tracer studies should use the same method, specifically, RTD truncation. We conclude that the choice of tracer data analysis method can greatly influence the quantifications of wetland hydraulics and removal rate.
This study investigated, using a lithium salt tracer, how macrophyte species and hydraulic loading rate (HLR) of wastewater influenced hydraulics in constructed wetlands (CWs). Four pilot-scale CWs ...received 45 mm day-1 of pre-treated sugar factory effluent and another four received 110 mm day-1. Half the CWs were planted with Cyperus papyrus and half with Echinochloa pyramidalis. Results showed a significant negative connection between tracer mass recovery and wetland water leakages. Also, a significant negative relationship between active wetland water volume and macrophyte density was detected. Further, a significant effect of HLR on mass removal rates of NH4+-N was observed. However, no significant effect of either HLR or macrophyte species on wetland hydraulic parameters was found.
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