Mass fluxes of nitrogen and phosphorus through water reclamation facilities: Case study of biological nutrient removal, aerobic sludge digestion, and sidestream recycle.

At water reclamation facilities, recycling of nutrients (nitrogen and phosphorus) from solids-handling processes to the mainstream treatment process can have detrimental effects on biological nutrient removal systems. In this study, mass fluxes of nitrogen and phosphorus were quantified through the treatment trains at the Northwest Regional Water Reclamation Facility (NWRWRF) and the adjoining Biosolids Management Facility (BMF), which receives sludge from several water reclamation facilities in Hillsborough County, Florida. The driving objectives were to determine (a) whether the return stream from BMF to NWRWRF (i.e., the "sidestream") represents a significant source of nitrogen and phosphorus to NWRWRF, and (b) whether the sidestream return from BMF is interfering with biological nutrient removal processes at NWRWRF. We determined that nearly half of the overall phosphorus flux into NWRWRF is recycled from the BMF sidestream. This leads to an increased cost of treatment, for example, for alum used in phosphorus removal at NWRWRF. In contrast to phosphorus, the flux of nitrogen from BMF to NWRWRF is small (~3%) compared with the flux of nitrogen entering NWRWRF in raw wastewater. However, nitrogen in the sidestream is mostly in the form of nitrate, which prevents anaerobic conditions from developing in the fermentation basin at NWRWRF, and thereby interferes with the enhanced biological phosphorus removal (EBPR) process. Some measurements suggest that fermentation and release of phosphorus may occur in the return activated sludge line (despite the relatively short residence time in that line), which supports EBPR and may partially compensate for anoxic (denitrifying) conditions in the fermentation basin. Therefore, overall, NWRWRF is able to meet its permit limits for phosphorus through a combination of EBPR and alum addition. Although the fluxes measured here are particular to the treatment systems under consideration, the general trends observed are likely to apply to many similar facilities that employ biological nutrient removal, aerobic digestion, and sidestream recycle, particularly those with regional biosolids management facilities. We recommend that such facilities consider (a) removal or recovery of phosphorus from their sidestreams and (b) returning sidestreams downstream of fermentation basins to avoid inhibition of EBPR processes. PRACTITIONER POINTS: Sidestreams from aerobic digestion can represent significant sources of phosphorus to mainstream wastewater treatment. Recycle of nitrate in aerobic digestion sidestreams can interfere with enhanced biological phosphorus removal (EBPR) during mainstream treatment. Fermentation of return activated sludge (RAS) can support EBPR, even under short average hydraulic residence times (minutes).

Novel Oleanolic and Maslinic Acid Derivatives as a Promising Treatment against Bacterial Biofilm in Nosocomial Infections: An in Vitro and in Vivo Study.

Oleanolic acid (OA) and maslinic acid (MA) are pentacyclic triterpenic compounds that abound in industrial olive oil waste. These compounds have renowned antimicrobial properties and lack cytotoxicity in eukaryotic cells as well as resistance mechanisms in bacteria. Despite these advantages, their antimicrobial activity has only been tested in vitro, and derivatives improving this activity have not been reported. In this work, a set of 14 OA and MA C-28 amide derivatives have been synthesized. Two of these derivatives, MA-HDA and OA-HDA, increase the in vitro antimicrobial activity of the parent compounds while reducing their toxicity in most of the Gram-positive bacteria tested, including a methicillin-resistant Staphylococcus aureus-MRSA. MA-HDA also shows an enhanced in vivo efficacy in a Galleria mellonella invertebrate animal model of infection. A preliminary attempt to elucidate their mechanism of action revealed that these compounds are able to penetrate and damage the bacterial cell membrane. More significantly, their capacity to reduce antibiofilm formation in catheters has also been demonstrated in two sets of conditions: a static and a more challenged continuous-flow S. aureus biofilm.

Synthesis and in vitro antiproliferative evaluation of PEGylated triterpene acids.

A set of PEGylated derivatives of oleanolic and maslinic acids has been semi-synthesised, attaching ethylene glycol, diethylene glycol, triethylene glycol or tetraethylene glycol to the C-28 carboxyl group of these natural triterpenes and some derivatives. Another set of PEGylated derivatives has been semi-synthesised by connecting the same four ethylene glycols to the hydroxyl groups of the A ring of these triterpenic acids, through a carbonate linker, by reaction with trichloromethyl chloroformate. The aqueous solubility of some of these PEGylated derivatives has been compared with that of maslinic acid. The cytotoxic effects of 28 triterpenic PEGylated derivatives in three cancer-cell lines (B16-F10, HT29, and Hep G2) have been assayed. The best results have been achieved with the HT29 cell line, and specifically with the oleanolic acid derivatives having ethylene glycol or tetraethylene glycol attached to the C-28 carboxyl group, which are approximately 27-fold more effective than their natural precursor. Eight PEGylated derivatives have been selected to compare the cytotoxicity results in the HT29 cancer-cell line with those of a non-tumour cell line of the same tissue (IEC-18), four of which were less cytotoxic in the non-tumour cell line. These compounds showed apoptotic effects on treated cells, with percentages of total apoptosis between 20% and 53%, relative to control, at 72h and IC50 concentration, and between 29% to 62%, relative to control, for the same time and IC80 concentration. We have also found that with the treatment of these compounds in HT29 cancer cells, cell-cycle arrest occurred in the G0/G1 phase. Finally, we have also studied changes in mitochondrial membrane potential during apoptosis of HT29 cancer cells, and the results suggest an activation of the extrinsic apoptotic pathway for these compounds.

Effect of the solvent and the sample preparation on the determination of triterpene compounds in two-phase olive-mill-waste samples.

A simple and rapid extraction method has been employed to determine several value-added compounds, mainly triterpenes, in two-phase olive-mill-waste samples. The compounds were extracted with methanol or ethyl acetate, and the initial fresh samples were treated for classic techniques such as drying, drying and oil extraction, and drying and sifting of the olive stones. For the identification and quantitation of the compounds, an ultra performance liquid chromatography-mass spectrometry method was employed. The best results of the triterpenic compound content were achieved by extraction with methanol from the fresh sample for the oleanolic and ursolic acids, and erythrodiol and uvaol; and from the dried-extracted sample for the maslinic acid. Conversely, the best results for the linoleic acid content were reached by extraction with ethyl acetate from the dried-sifted sample. These are remarkable processes that make the solid wastes from the olive-oil industry reach a high added value.

Identification in Rat Plasma and Urine by Linear Trap Quadrupole-Orbitrap Mass Spectrometry of the Metabolites of Maslinic Acid, a Triterpene from Olives.

Maslinic acid is a natural pentacyclic triterpenoid widely distributed in edible and medicinal plants with health-promoting activities. The identification and quantification of its metabolites is a requirement for a better understanding of the biological effects of this triterpene. Therefore, maslinic acid was orally administered to Sprague-Dawley rats at a dose of 50 mg/kg of body weight. Blood and urine were withdrawn at 45 min. Samples were extracted with ethyl acetate prior to liquid chromatography-atmospheric pressure chemical ionization-linear trap quadrupole-Orbitrap (LC-APCI-LTQ-Orbitrap) analysis. Screening of plasma yielded four monohydroxylated derivatives (M1-M4), one monohydroxylated and dehydrogenated metabolite (M5), and two dihydroxylated and dehydrogenated compounds (M6 and M7). In urine, M1, M4, M5, and M6 were detected. Quantification by LC-APCI-mass spectrometry (MS) revealed maslinic acid as the prevalent compound in both plasma (81.8%) and urine (73.9%), which indicates that metabolism is low and mainly attributable to phase I reactions.

Semi-synthesis of acylated triterpenes from olive-oil industry wastes for the development of anticancer and anti-HIV agents.

A broad set of potential bioactive conjugate compounds has been semi-synthesized through solution- and solid-phase organic procedures, coupling two natural pentacyclic triterpene acids, oleanolic (OA) and maslinic acids (MA), at the hydroxyl groups of the A-ring of the triterpene skeleton, with 10 different acyl groups. These acyl OA and MA derivatives have been tested for their anti-proliferative (against the b16f10 murine melanoma cancer cells) and antiviral (as inhibitors of the HIV-1-protease) effects. Several derivatives have shown high levels of early and total apoptosis (up to 90%). Most of the compounds that exhibited anti-proliferative effects also generated ROS, probably involving the activation of an intrinsic apoptotic route. The only four compounds that did not cause the release of ROS could be related to the participation of a probable extrinsic activation of the apoptosis mechanism. A great number of these acyl OA and MA derivatives have proved to be potent inhibitors of the HIV-1-protease, the most active inhibitors having IC50 values between 0.31 and 15.6 µM, these values being between 4 and 186 times lower than their non-acylated precursors. The potent activities exhibited in the apoptosis-activation processes and in the inhibition of the HIV-1-protease by some OA and MA acylated derivatives imply that these compounds could be used as new, safe, and effective anticancer and/or antiviral drugs.

Bioactive compounds with added value prepared from terpenes contained in solid wastes from the olive oil industry.

Starting from solid wastes from two-phase olive-oil extraction, the pentacyclic triterpenes oleanolic acid and maslinic acid were isolated. These natural compounds were transformed into methyl olean-12-en-28-oate (5), which then was transformed into several seco-C-ring triterpene compounds by chemical and photolytic modifications. The triene seco-products were fragmented through several oxidative procedures to produce, simultaneously, cis- and trans-decalin derivatives, both potential synthons for bioactive compounds. The chemical behavior of the isolated fragments was investigated, and a suitable approach to several low-molecular-weight terpenes was performed. These are interesting processes for the value-addition to solid waste from the olive-oil industry.

ent-Kauranoid derivatives from Sideritis moorei.

Seven new ent-kauranoid derivatives ent-7alpha,18-dihydroxykaur-16-en-3-one, ent-18-acetoxy-3beta,7alpha-dihydroxykaur-15-en-17-al, ent-3beta-acetoxy-7alpha,18-dihydroxykaur-15-en-17-al, ent-18-acetoxy-3beta,7alpha,17-trihydroxykaur-15-ene, ent-3beta-acetoxy-7alpha,17,18-trihydroxykaur-15-ene, ent-18-acetoxy-3beta,7alpha,17-trihydroxy-15beta,16beta-epoxykaurane and ent-3beta-acetoxy-7alpha,17,18-trihydroxy-15beta,16beta-epoxykaurane have been isolated from Sideritis moorei. The structures of these compounds have been established by spectroscopic means and chemical correlations.

Antioxidant activity of maslinic acid, a triterpene derivative obtained from Olea europaea.

We investigated the effect of maslinic acid (a triterpene derivative obtained from olive pomace), on the susceptibility of plasma or hepatocyte membranes to lipid peroxidation (LPO), induced respectively by the hydroxyl radical (OH*) generated by Fe2+/H2O2 ex vivo and by the system Fe3+/ascorbate in vitro; moreover, three groups of animals used in the plasma study were pretreated with CCl4 (to generate CCl3-*). Endogenous plasma lipoperoxide levels and susceptibility to LPO were decreased in rats treated with maslinic acid, after exposure to OH* by Fe2+/H2O2 (Fenton reaction). Co-incubation with maslinic acid prevented hepatocyte membrane LPO as shown by the reduction of TBARS. In conclusion, maslinic acid may offer some advantages in the resistance of oxidative stress in the animals.

Coffee increases state anxiety in males but not in females.

Coffee, reproducing the conditions under which caffeine is normally ingested, containing 3, 75, 150 or 300 mg of caffeine was given to healthy male and female volunteers. 25-30 min after drinking the beverage, they completed the Spanish version of the state-trait anxiety inventory (STAI). The beverage increased state anxiety, in a dose-dependent manner, in males but not in females. This could be due to a lesser sensitivity of females to coffee.