Municipal wastewater treated by membrane bioreactor, either aerobically (AeMBR) or anaerobically (AnMBR), can be reused to irrigate crops. However, post-AeMBR and post-AnMBR effluent have different ...water quality that may impact crop growth and yield. This study aims to assess for differences in water quality from both AeMBR and AnMBR, and determine if the type of treated wastewater matrix would impact seed germination and crop yield. Compared to post-AeMBR and control, post-AnMBR effluent had a negative impact on seed germination for both tomatoes and lettuces. The use of post-AnMBR but not post-AeMBR effluent also resulted in a higher number of unripe tomato fruits at the time of harvesting. However, when post-AnMBR effluent was diluted to 25% and 75% v/v with tap water, higher lettuce biomass was harvested compared to the same concentrations of post-AeMBR effluent and control. The observed differences in germination and yield were likely due to differences in the concentrations of heavy metals (e.g. Zn) and steroids or phytohormones (e.g. testosterone, gibberellic acid) present in both post-MBR effluents. This study demonstrated that the type of treated wastewater generated from different upstream treatment technologies can potentially impact crop yield based on the crop type. By understanding how the type of treated wastewater affect downstream agricultural activities, changes in management practices can be made accordingly.
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•Post-AnMBR and post-AeMBR effluent have different water quality that impacted crop growth and yield.•Post-AnMBR effluent detrimentally impacted lettuce and tomato seed germination.•Post-AnMBR effluent increased the harvested lettuce weight.•Post-AnMBR effluent delayed the tomato fruit ripening process.•Soil microbiota can change upon exposure to post-MBR effluent.
Increasing human activity, including commercial and noncommercial use of pharmaceuticals, personal care products, and agricultural products, has introduced new contaminants that can be challenging to ...remove with currently available technologies. Pharmaceuticals, in particular, can be especially challenging to remove from the water supply and can pose great harm to people and local ecosystems. Their highly stable nature makes their degradation with conventional water treatment techniques difficult, and studies have shown that even advanced treatment of water is unable to remove some compounds. As such, decontamination of water from pharmaceuticals requires the development of advanced technologies capable of being used in indirect and direct potable water reuse. In this review, we discuss pharmaceutical removal in indirect potable water treatment and how recent advancements in adsorption and photocatalysis technologies can be used for the decontamination of pharmaceutical-based emerging contaminants. For instance, new materials that incorporate graphene-based nanomaterials have been developed and shown to have increased adsorptive capabilities toward pharmaceuticals when compared with unmodified graphene. In addition, adsorbents have been incorporated in membrane technologies, and photocatalysts have been combined with magnetic material and coated on optical fibers improving their usability in water treatment. Advancements in photocatalytic material research have enabled the development of highly effective materials capable of degradation of a variety of pharmaceutical compounds and the development of visible-light photocatalysts. To understand how adsorbents and photocatalysts can be utilized in water treatment, we address the benefits and limitations associated with these technologies and their potential applicability in indirect potable water reuse plants.
Keeping an effective disinfectant residual concentration in reclaimed water is still a challenge, due to its high levels of ammonia and organic matter when compared with those in drinking water. This ...research proposes the integration of the reaction schemes of monochloramine auto-decomposition with an empirical kinetic mechanism accounting for reactive chlorine species decay in the presence of organic matter, for which three mechanisms were hypothesized and tested. A parallel second order mechanism, where monochloramine reacts both with fast and slow organic matter reactive fractions, was identified as the most suitable. The model, comprising two rate constants and two fictive concentrations of organic matter as parameters, was further successfully calibrated with real reclaimed waters with two initial free chlorine doses of 8.01×10−5 M (≈5 mg/L) and 2.67×10−4 M (≈20 mg/L). The proposed model is believed to support future studies aiming to predict and manage chlorine decay in reclaimed water distribution systems.
A green technique that emerged as a promise in the degradation of numerous organic contaminants is photocatalysis. The aim of this study concerns photocatalytic degradation of organic using titanium ...dioxide nano particles (TiO
NPs) which syntheses from ilmenite by different leaching methods using different ingredients such as HCl, HNO
and Aqua Regia. The affecting factors such as rate of addition, reaction time, ilmenite grain size, acid to ilmenite ratio and reaction temperature were conducted. Comprehensive physicochemical characterization of Ilmenite and TiO
NPs were conducted using different analytical techniques such as XRD, XRF, SEM, TEM and FTIR. Photocatalytic degradation of organics is confirmed by studies of affecting factors on the effectiveness of TiO
NPs such as dose, agitation forces, light intensity, initial concentration, pH, time, and temperature. The removal percentages of TSS, COD, BOD and TN of organics were explored. From the results the maximum removal percentage of TSS were 97.3 and 96.9% before and after secondary treatment conducted using ferric chloride (FC). The maximum removal percentage of TKN, BOD, and COD before secondary treatment were conducted using mixture of TiO
NPs, FC, and chitosan, which reached 44.2, 44 and 46.3%, respectively. The maximum removal percentage of TKN, BOD, and COD after secondary treatment were conducted using mixture of TiO
NPs, FC, and chitosan, which reached 94.9, 99.7 and 99.6%, respectively. Overall, the results derived from this investigation suggest that the TiO
NPs/UV holds significant advanced treatment of sewage water, making it a viable choice for water reuse applications.
Advanced treatment technologies are being assessed as a proactive measure to assist with the transformation of treated wastewater into a source of water for potable water production. We investigated ...the biological effects along an advanced water treatment pilot plant, using zebrafish embryos throughout early development. The study compared phenotypic observations with global transcriptome responses, enabling us to keep an open mind about the chemicals that might influence the biological activity. There was no evidence of acute toxicity at any treatment stage, but skeletal, cardiovascular and pigmentation changes occurred in a small proportion of embryos along the treatment process, and in a tap water; not detected in the aquarium water control. Reverse osmosis (RO) reduced the concentration of measured chemical contaminants in the water the most, while eliminating the occurrence of abnormalities detected in fish embryos. Conversely, advanced oxidation reversed the benefits of RO treatment by increasing the frequency of teratogenic and sub-lethal abnormalities seen. Using the molecular responses of zebrafish embryos to different IPR water, we report the bioactivity within the water at different stages of advanced treatment and associate these to perturbed biological functions. Transcriptomic analysis revealed alterations to the retinoid system, which was consistent with the observed teratogenic effects. Changes to tryptophan metabolism (associated with the production of melatonin required for the control of normal circadian rhythms) and somatolactin-beta (associated with normal pigmentation in fish) were also found. We show that underexplored forms of biological activity occur in treated wastewater effluent, and/or may be created depending on the type of advanced treatment process used. By integrating the available analytical chemistry we highlight chemical groups associated to this response. Our study shows that more detailed and in-depth characterisation of chemicals and biological pathways associated with advanced treatment water systems are needed to mitigate possible risks to downstream organisms.
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•Safety of treatment technologies for indirect potable reuse investigated•A low incidence of abnormalities seen in exposed embryos•Transcriptomics linked teratogenicity to altered retinol metabolism.•Changes to retinol metabolism were associated with metalloids.•More research into retinoid disrupting chemicals needed
Water reuse to address water security Tortajada, Cecilia
International journal of water resources development,
07/2021, Volume:
37, Issue:
4
Journal Article
Reused water policies for potable use Tortajada, Cecilia; Nam Ong, Choon
International journal of water resources development,
07/2016, Volume:
32, Issue:
4
Journal Article
Water scarcity and strict legislation make water reuse in dye related industries like textile and leather become more important. Among the different types of dyes, soluble dyes are the most ...problematic. Nanofiltration was vital for the treatment of dye wastewater but the major limitation is fouling. Coagulation/flocculation can be effective to enhance nanofiltration performance towards water reuse and minimisation of fouling. The selection of the coagulant type (metal or polymer) and dosages are very critical in this technique. Factors that improved the coagulation were studied in detail and suitable metal coagulants were presented. Cationic, anionic and natural polymers as flocculant aids were also reported for successfully enhancing dye removal. Adding a suitable type of metal coagulant-polymer at an optimum dosage and mixing conditions increases the dye removal at a wider range of operating pH and reduces the production of sludge. In-depth studies on the effect of metal coagulant-polymer on membrane fouling are still lacking and visualisation techniques might be helpful in this regard.
•Equivalent water productivity (WP) was proposed and proved to be useful in WP assessment.•WP is scale dependent due to water reuse through shallow groundwater systems.•Natural vegetation should not ...be ignored when considering water productivity of a whole region.•Water reuse reduces WP compared with direct use in salt affected areas.•Efficient irrigation systems are needed for WP improvement in salt affected areas.
Water productivity (WP) expressed as the yield produced per unit volume of water is an important indicator of water use in arid and semi-arid areas. Due to complex plant cover and hydrological processes, the quantification and assessment of WP are usually difficult to determine, especially at the regional scale. In this study, an arid irrigated agro-ecosystem in the upper Yellow River basin was selected as a case study area. Based on field observation and model simulation results, the WP of irrigation water (WPI), water applied (WP(I+P)) and evapotranspiration (WPET) were calculated. Equivalent water productivity (EWP) of irrigation water (EWPI), water applied (EWP(I+P)) and evapotranspiration (EWPET) were proposed and calculated to unify the disparate WP for various crops and natural vegetation. Results showed WPI and WP(I+P) decreased with the increase of water application for all plants except watermelon, indicating supplemental irrigation to watermelon is urgent to improve its production and WP(I+P). The spatially averaged WPET (kg m−3) was 2.47 for maize, 0.80 for sunflower, 12.3 for watermelon, 1.39 for wheat and 0.65 for natural vegetation. WPET for natural vegetation was usually lower in this salt stressed area compared with other water stressed areas. The EWP revealed the rank order of WP for different crops and natural vegetation: watermelon > wheat > maize > sunflower for EWPI; natural vegetation > wheat > watermelon > maize > sunflower for EWP(I+P); and wheat > sunflower > watermelon > maize > natural vegetation for EWPET. The relationship between EWP(I+P) and EWPET was scale dependent due to the water reuse phenomena among different land cover types and the canals through the shallow groundwater system. Ignoring natural vegetation will result in considerable bias in the estimation of the regional scale water productivity (16 % in this study). WP improvement strategies such as transferring irrigation water from less productive (sunflower) areas to productive (vegetable and natural vegetation) areas, reducing bare soil evaporation and constructing a timely and accurate irrigation-drainage system were provided.
Egypt faces great challenges to manage its limited freshwater resources. Shortage in freshwater, due to expected stresses of climatic changes and upper Nile projects, will have major impacts on ...Egypt's water and food security. About 85% of the annual total freshwater resource is consumed by agriculture. The objective of this work is to assess the future water security situation of Kafr El-Sheikh governorate, Nile Delta, Egypt, under climate change and urbanization stresses, compared to the current situation. Main investigated water security elements for this study were the irrigation water requirements and agricultural land areas. Two different reference evapotranspiration equations were used to calculate the future irrigation water requirements under three different Representative Concentration Pathways (RCP) (2.6, 4.5 and 8.5 scenarios) for the period 2010–2100, based on the intergovernmental panel on climate change’s 5th assessment report. Remote sensing and Geographical Information System (GIS) were used to generate a land use classification map, which was used to estimate the losses in each land use category of the study area under 0.5 and 1.0 m relative sea level rise (SLR) estimates. Combined scenarios of future changes in irrigation water consumption and agricultural land area were analysed. The results show that the future water security situation of the governorate is highly sensitive to projected climatic changes. Moreover, most future scenarios revealed that the agricultural land area would decrease, which will cause serious food security problems. The maximum decrease by about 55.9% of the agricultural land area for year 2095 compared to year 2016 is estimated, due to the current annual decreasing rate of 0.4% and 1.0 m SLR, whatever the applied RCP scenario. While the maximum increase in the required irrigation water would be about 6% due to the RCP85 scenario, assuming no change in the irrigation land area, with a mixing ratio of 1.34 (freshwater): 1 (drainage water) which would affect the crop yield productivity. A regular assessment of water security elements for each of the Egyptian governorates should be managed and an urgent integrated plan for food security to adapt with the future climate change impacts is essential.
•Future climatic and land use changes should be combined to estimate future impacts.•Selection of evapotranspiration equations affects future projected values.•Future water security situation of the governorate is highly sensitive to projected climatic changes.•Expected shortage in agricultural land area due to urban sprawl and/or sea level rise will significantly affect the Egyptian food security.
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