Search

We evaluated the removal capacity of a coupled microalgal-bacterial biofilm (CMBB) to eliminate three recalcitrant pharmaceuticals. The CMBB's efficiency, operating at different biofilm concentrations, with or without light, was compared and analyzed to correlate these parameters to pharmaceutical removal and their effect on the microorganism community. Removal rates changed with changing pharmaceutical and biofilm concentrations: higher biofilm concentrations presented higher removal. Removal of 82-94% venlafaxine and 18-51% carbamazepine was obtained with 5 days of CMBB treatment. No iohexol removal was observed. Light, microorganism composition, and dissolved oxygen concentration are essential parameters governing the removal of pharmaceuticals and ammonia. Chlorophyll concentration increased with time, even in the dark. Three bacterial phyla were dominant: Proteobacteria, Bacteroidetes and Firmicutes. The dominant eukaryotic supergroups were Archaeplastida, Excavata and SAR. A study of the microorganisms' community indicated that not only do the species in the biofilm play an important role; environment, concentration and interactions among them are also important. CMBB has the potential to provide low-cost and sustainable treatment for wastewater and recalcitrant pharmaceutical removal. The microenvironments on the biofilm created by the microalgae and bacteria improved treatment efficiency.

Arsenic (As) contamination of freshwater resources constitutes a major environmental issue affecting over 200 million people worldwide. Although the use of microorganisms for the bioremediation of As has been well studied, only very few candidates have been identified to date. Here, we investigated bacteria associated with the Red Sea sponge Theonella swinhoei and their potential to reduce As in a low-salinity liquid medium. This Indo-Pacific common sponge has been shown to hyper-accumulate As, at an average concentration of 8600 mg/g-1 in an environment uncontaminated by arsenic or barium. Four isolated strains of bacteria exhibited arsenic reduction potential by transforming inorganic As in the form of arsenate (iAsV) to arsenite (iAsIII). Two of these isolates were identified as Alteromonas macleodii and Pseudovibrio ascidisceicola, and the other two isolates, both belonging to the same species, were identified as Pseudovibrio denitrificans. The four isolates were then cultured in a low-salinity iAsV-rich medium (5 mM) and As concentration was measured over time using a specifically designed high-performance liquid chromatograph coupled to a mass spectrometer (HPLC-MS). Out of the four isolates, A. macleodii and P. ascidisceicola grew successfully in a low-salinity liquid medium and reduced AsV to AsIII at an average rate of 0.094 and 0.083 mM/h, respectively, thereby demonstrating great potential for the bioremediation of As-contaminated groundwater.

Solid-phase extraction (SPE) based on trimethylsilyloxy-modified silica aerogel was developed for extraction of chemotherapeutic drugs from water. The developed method is easy and affordable, can be performed in separating funnel and does not require a vacuum and SPE manifold. The extraction and recovery of cyclophosphamide (CYP), dexamethasone (DEX), and paclitaxel (TAX) by the aerogel from water were investigated. The factors governing the extraction efficiency such as sample pH, sample volume, volume of eluent and concentration of analytes were studied. The LOD and LOQ of the developed method were calculated and linearity was found in the range of 4–100 μg L−1. The extraction efficiency of the aerogel was compared to that of other SPE cartridges, Oasis HLB, Strata-X-C, C18 and polymeric reversed phase, and the aerogel showed similar or better performance than the other commercial cartridges available on the market. The developed method was also used to extract chemotherapeutic drugs spiked in hospital wastewater.

Advanced technologies, such as reverse osmosis (RO), allow the reuse of treated wastewater for direct or indirect potable use. However, even highly efficient RO systems produce ~10&ndash, 15% highly contaminated concentrate as a byproduct. This wastewater RO concentrate (WWROC) is very rich in metal ions, nutrients, and hard-to-degrade trace organic compounds (TOrCs), such as pharmaceuticals, plasticizers, flame retardants, and detergents, which must be treated before disposal. WWROC could be up to 10 times more concentrated than secondary effluent. We examined the efficiency of several advanced oxidation processes (AOPs) on TOrC removal from a two-stage WWROC matrix in a pilot wastewater-treatment facility. WWROC ozonation or UV irradiation, with H2O2 addition, demonstrated efficient removal of TOrCs, varying between 21% and over 99% degradation, and indicating that radical oxidation (by HO&middot, ) is the dominant mechanism. However, AOPs are not sufficient to fully treat the WWROC, and thus, additional procedures are required to decrease metal ion and nutrient concentrations. Further biological treatment post-AOP is also highly important, to eliminate the degradable organic molecules obtained from the AOP.

This study represents, detailly, the validated method for the extraction and quantification of widespread phthalic acid esters (PAEs) bis(2-ethylhexyl) phthalate (DEHP), di-n-butyl phthalate (DBP) and di-n-octyl phthalate (DnOP) from solitary ascidians collected from a marine environment. The extraction was based on a pressurized liquid extraction method, using n-hexane as the solvent to extract the target PAEs from dry biological tissues, and was performed in an accelerated solvent extraction instrument. The average recovery of 89.2% was obtained from samples subjected to a pressure of ~1500 psi and 120°C in two 10-min cycles. GC-MS was used for quantification, conducted in single-ion monitoring mode. Following careful and rigorous cleanup procedures to prevent cross-contamination from laboratory glassware, PAE standards showed signals with good specificity. The obtained limits of detection were 130, 122 and 89 ng/g for DEHP, DBP and DnOP, respectively. Accordingly, the calculated limits of quantification were 394, 370 and 270 ng/g for DEHP, DBP and DnOP, respectively. The obtained linearity ranged from 5.4 to 269 ng/ml (equivalent to 135 - 6725 ng/g dry weight), with R2 ≥ 0.998. Concentrations in the range of 200 to 9000 and 400 to 5000 ng/g sample dry weight, for DEHP and DBP, respectively, were obtained from the ascidians. No DnOP was detected in any of the samples. These results indicate that the method presented in this study is applicable for detection of low and trace concentrations of the target PAEs in samples collected from a marine organism, which can serve as a bioindicator of plastic contamination.

Antibiotic resistance poses a serious threat to global public health, and antibiotic resistance determinants can enter natural aquatic systems through discharge of wastewater effluents. Hospital wastewater in particular is expected to contain high abundances of antibiotic resistance genes (ARGs) compared to municipal wastewater because it contains human enteric bacteria that may include antibiotic-resistant organisms originating from hospital patients, and can also have high concentrations of antibiotics and antimicrobials relative to municipal wastewater. Viruses also play an important role in wastewater treatment systems since they can influence the bacterial community composition through killing bacteria, facilitating transduction of genetic material between organisms, and modifying the chromosomal content of bacteria as prophages. However, little is known about the fate and connections between ARGs, viruses, and their associated bacteria in hospital wastewater systems. To address this knowledge gap, we characterized the composition and persistence of ARGs, dsDNA viruses, and bacteria from influent to effluent in a pilot-scale hospital wastewater treatment system in Israel using shotgun metagenomics. Results showed that ARGs, including genes conferring resistance to antibiotics of high clinical relevance, were detected in all sampling locations throughout the pilot-scale system, with only 16% overall depletion of ARGs per genome equivalent between influent and effluent. The most common classes of ARGs detected throughout the system conferred resistance to aminoglycoside, cephalosporin, macrolide, penam, and tetracycline antibiotics. A greater proportion of total ARGs were associated with plasmid-associated genes in effluent compared to in influent. No strong associations between viral sequences and ARGs were identified in viral metagenomes from the system, suggesting that phage may not be a significant vector for ARG transfer in this system. The majority of viruses in the pilot-scale system belonged to the families Myoviridae, Podoviridae, and Siphoviridae. Gammaproteobacteria was the dominant class of bacteria harboring ARGs and the most common putative viral host in all samples, followed by Bacilli and Betaproteobacteria. In the total bacterial community, the dominant class was Betaproteobacteria for each sample. Overall, we found that a variety of different types of ARGs and viruses were persistent throughout this hospital wastewater treatment system, which can be released to the environment through effluent discharge.

In this study, we present an innovative new bio-treatment approach for 17&alpha, ethynyestradiol (EE2). Our solution for EE2 decontamination was accomplished by using the SBP (Small Bioreactor Platform) macro-encapsulation method for the encapsulation of two bacterial cultures, Rhodococcus zopfii (R. zopfii ) and Pseudomonas putida F1 (P. putida). Our results show that the encapsulated R. zopffi presented better biodegradation capabilities than P. putida F1. After 24 h of incubation on minimal medium supplemented with EE2 as a sole carbon source, EE2 biodegradation efficacy was 73.8% and 86.5% in the presence of encapsulated P. putida and R. zopfii, respectively. In the presence of additional carbon sources, EE2 biodegradation efficacy was 75% and 56.1% by R. zopfii and P. putida, respectively, indicating that the presence of other viable carbon sources might slightly reduce the EE2 biodegradation efficiency. Nevertheless, in domestic secondary effluents, EE2 biodegradation efficacy was similar to the minimal medium, indicating good adaptation of the encapsulated cultures to sanitary effluents and lack of a significant effect of the presence of other viable carbon sources on the EE2 biodegradation by the two encapsulated cultures. Our findings demonstrate that SBP-encapsulated R. zopfii and P. putida might present a practical treatment for steroidal hormones removal in wastewater treatment processes.

Compounds such as terpenes, alcohols and aldehydes, are key odorants in orange juice. One of the common methods to evaluate the concentration of odorants is headspace-gas chromatography (HS-GC). The concentration of odorants found in the gas phase indicates on their concentration in the liquid, and together with their odor thresholds, can be directly related to odor sensation. However, the addition of water to samples of orange juice concentrate (OJC) that reduces the absolute odorants concentrations in the liquid, seems to significantly increase the signal response of terpenes and long-chain aldehydes measured in the gas phase. This study indicates the effect of water content in OJC on the detection and the intensity of odorants in the gas phase. Therefore, these results demonstrate that water has a significant role in the transition of odor to the gas phase above the liquid matrix.

Global increase in the use of pharmaceutically-active compounds (PhACs), and their insufficient removal in wastewater treatment plants, have resulted in their continuous release into the marine environment. We investigated the use of the solitary ascidians Herdmania momus, Microcosmus exasperatus, and Styela plicata as bioindicators of three common PhACs in the Israeli coastal waters: Bezafibrate, carbamazepine and diclofenac. Both the Mediterranean and the Red-Sea coasts were found contaminated with PhACs, detected at all 11 sampling sites, with four sites contaminated with all three studied PhACs. Diclofenac was most frequent, present in nine of the 11 sites with concentrations reaching 51.9 ng/g of dry weight sample (dw). Bezafibrate and carbamazepine reached concentrations of 47.8 ng/g dw and 14.3 ng/g dw, respectively. The alarming detection of such high concentrations of PhACs in ascidians along Israel's coasts demonstrates both the extent of PhACs contamination in the region, and the potential of ascidians as bioindicators, and emphasizes the urgent need for additional research into PhAC contamination sources and effects.

Microalgae applications are becoming more and more diverse, from wastewater treatment to biofuel and plastics production. Another promising and sustainable application is the removal of organic compound from drinking water and wastewater sources. This study focused on the removal of the iodinated contrast media, iohexol by the microalga Chlorella vulgaris. C. vulgaris removed 40–50% of the iohexol from the medium in 27 days, 23–30% of which was biodegraded through two main pathways: oxidation and hydrolysis. Similar transformation pathways, producing the same degradation products, were observed for incubation with microalgae and for ozonation.

The interaction of microplastic (MP) with marine organisms is crucial for understanding the significant effect that MP and its additives may have on marine environments. However, knowledge regarding the magnitude of these pollutants in the Eastern Mediterranean Sea and the tropical Red Sea is still scarce. Here we examined the levels of phthalate acid esters (PAEs) and MP in Herdmania momus and Microcosmus exasperatus sampled along the Mediterranean and Red Sea coasts of Israel. High levels of dibutyl phthalate (DBP) and bis (2‑ethylhexyl) phthalate (DEHP) were found in ascidians at the majority of sampling sites, and MP particles were found in ascidians at all sites. As efficient filter-feeders and being widely-distributed, invasive ascidians present fundamental opportunities for the environmental monitoring of microplastic and its additives worldwide. The high levels of pollutants revealed emphasize the need for further research into the magnitude and effects of MP and PAEs in these regions.

Plastic products in municipal solid waste result in the extraction of phthalates in leachate that also contains large amounts of organic matter, such as humic substances, ammonia, metals, chlorinated organics, phenolic compounds, and pesticide residues. Phthalate esters are endocrine disruptors, categorized as a priority pollutant by the US Environmental Protection Agency (USEPA). Biological processes are inefficient at degrading phthalates due to their stability and toxic characteristics. In this study, the peroxone (ozone/hydrogen peroxide) process (O3/H2O2), an O3-based advanced oxidation process (AOP), was demonstrated for the removal of diethyl phthalate (DEP) in synthetic leachate simulating solid-waste leachate from an open dump. The impact of the O3 dose during DEP degradation, the formation of ozonation intermediate by-products, and the effects of H2O2 dose, pH, and ultraviolet absorbance at 254 nm (UVC) were determined during ozonation. Removal of 99.9% of an initial 20 mg/L DEP was obtained via 120 min of ozonation (transferred O3 dose = 4971 mg/L) with 40 mg/L H2O2 in a semi-batch O3 system. Degradation mechanisms of DEP along with its intermediate products were also determined for the AOP treatment. Indirect OH radical exposure was determined by using a radical probe compound (pCBA) in the O3 treatment.