Blanca Jiménez

The analysis of a group of acidic pharmaceuticals, carbamazepine, and potential endocrine disrupting compounds in wastewater irrigated soils by gas chromatography-mass spectrometry.

The analysis of pharmaceuticals and potential endocrine disruptors in the environment has rightly concentrated on their presence in wastewaters and possible contamination of receiving bodies, such as groundwaters. However, wastewater is increasingly being reused for irrigation and in order to fully understand the environmental fate of these compounds, reliable methods for their analysis in soil are required, of which there are relatively few available. This article reports a method for a range of acidic pharmaceuticals, carbamazepine, and endocrine disrupting compounds in soils with final analysis by gas chromatography-mass spectrometry. Two soil types (Phaeozom and Leptosol) and three fortification levels were used to validate the method. Recoveries of acidic pharmaceuticals varied between 62 and 102%, carbamazepine from 75 to 118%, and potential endocrine disruptors between 54 and 109%; most recoveries were between 75 and 95% and relative standard deviations were generally less than 10%. Detection limits were between 0.25 and 2.5 ng/g except for phthalates and 4-nonylphenols (25 ng/g). The method was used to analyze soils where untreated wastewaters have been used to irrigate crops for approximately 90 years. Concentrations of acidic pharmaceuticals in the soil were <1 ng/g and potential endocrine disruptors varied from below the limit of detection (estrone, 17beta-estradiol, and 17alpha-ethinylestradiol) to 2079 ng/L (bis-diethylhexyl phthalate). This data indicated that despite the continuous application of the contaminants over many years, concentrations were generally lower than those expected to be contributed by a single irrigation event. Only carbamazepine, at concentrations of 6.48 ng/g (in Phaeozem) and 5.14 ng/g (in Leptosol), showed any evidence of persistence in the soils analyzed.

Dextran blue colorant as a reliable tracer in submerged filters

Abstract A reliable method to evaluate residence time distribution in submerged filters is presented. This method is useful even when using a porous packing. The tracer employed is Dextran blue, which is better detected in the u.v.-zone (220 nm). The advantage of this colorant is that it avoids the tailing phenomenon, allowing accurate mean retention time evaluation. The tailing phenomenon is explained using the diffusion theory.

Ultrasound-assisted emulsification–microextraction of fragrance allergens in water

A method based on ultrasound-assisted emulsification-microextraction (USAEME) and gas chromatography-mass spectrometry (GC-MS) has been developed for the analysis of regulated fragrance allergens in water. Extraction conditions such as the type of solvent, extraction temperature, irradiation time, and salting-out effect were optimized using a multivariate approach. Compounds were extracted during 2 min in an acoustically emulsified media formed by 100 μL chloroform and 10 mL sample. The USAEME process provided an efficient and exhaustive extraction (enrichment factor ∼100) and, after centrifugation, the extract was ready for GC analysis. Validation was performed using spiked ultrapure water as well as other most complex matrices such as sewage water. Recoveries between 75% and 110% were generally obtained, and precision was characterized by RSD values <10% in most cases. The limits of detection (LODs) were at the sub-nanogram per millilitre level. The proposed procedure was applied to the determination of allergens in several real samples including tap water, baby bathwater, recreational place water, public washing place water, and sewage water. The presence of some of the target compounds was confirmed in all the samples excluding tap water, demonstrating the ubiquity of this group of cosmetic and personal care products ingredients.

Selected dyes for residence time distribution evaluation in bioreactors

A selection of dyes for tracer studies in bioreactors, specially for wastewater treatment, is presented. Substances that showed no adsorption on air or biomass, stability in time, good solubility and no color change between pH 6.5 to 8.5, were: bromocresol green, bromophenol blue, dextran blue, eosin Y and mordant violet. Consequently they seem to be adequate for common biochemical engineering processes. In addition, dyes that showed some limitations, but may be employed in special cases, were: bromophenol red and phenol red (color change between pH 5.0 to 6.8 and 6.8 to 8.4 respectively) and methylene violet Bernsthen (low spectrophotometric response).

Production and characterization of a Ca-alginate biocatalyst for removal of phenol and chlorophenols from wastewaters

Abstract The production of a Ca-alginate/Pseudomonas fluorescens biocatalyst, for the removal of phenol, chlorophenol, dichlorophenol, and trichlorophenol from wastewaters was studied. Rheological characterization (before and after heat treatment) of the Na-alginate solution was carried out. The effect of some operational parameters of production including air pressure, alginate solution concentration, feed rate, and alginate/cells ratio, on the size and quality of the spheres was evaluated. In addition, a study of the biocatalyst including the quantity of cells entrapped into the alginate spheres, the apparent and real catalyst densities, the humidity and the e void fraction was carried out together with a kinetic characterization of the Ca-alginate spheres through a first order expression. Finally, an assessment of the catalyst in the biodegradation of phenol, mono, di-, and trichlorophenol at medium-high concentrations (1000, 500, 400 and 100 mg l 1) is presented and discussed.

Wastewater irrigation and health: challenges and outlook for mitigating risks in low-income countries

In Drechsel, Pay; Scott, C. A.; Raschid-Sally, Liqa; Redwood, M.; Bahri, Akissa (Eds.). Wastewater irrigation and health: assessing and mitigating risk in low-income countries. London, UK: Earthscan; Ottawa, Canada: International Development Research Centre (IDRC); Colombo, Sri Lanka: International Water Management Institute (IWMI).In most developing countries wastewater treatment systems have very low coverage or function poorly, resulting in large-scale water pollution and the use of poor-quality water for crop irrigation, especially in the vicinity of urban centres. This can pose significant risks to public health, particularly where crops are eaten raw. Wastewater Irrigation and Health approaches this serious problem from a practical and realistic perspective, addressing the issues of health risk assessment and reduction in developing country settings. The book therefore complements other books on the topic of wastewater which focus on high-end treatment options and the use of treated wastewater. This book moves the debate forward by covering also the common reality of untreated wastewater, greywater and excreta use. It presents the state-of-the-art on quantitative risk assessment and low-cost options for health risk reduction, from treatment to on-farm and off-farm measures, in support of the multiple barrier approach of the 2006 guidelines for safe wastewater irrigation published by the World Health Organization. The 38 authors and co-authors are international key experts in the field of wastewater irrigation representing a mix of agronomists, engineers, social scientists and public health experts from Africa, Asia, Europe, North America and Australia. The chapters highlight experiences across the developing world with reference to various case studies from sub-Saharan Africa, Asia, Mexico and the Middle East. The book also addresses options for resource recovery and wastewater governance, thus clearly establishes a connection between agriculture, health and sanitation, which is often the missing link in the current discussion on حaking wastewater an assetٮ

Coagulation-flocculation pretreatment of high-load chemical-pharmaceutical industry wastewater: mixing aspects

The selection of a coagulant-flocculant agent which, based on the maximum chemical oxygen demand removal, warrants the best performance of the removal system for a very complex high-load chemical-pharmaceutical industry wastewater, is described. A total of 23 coagulants/flocculants was tested, including salts, poly-hidroxyaluminates, synthetic polymers as well as natural gums. In a second stage, some mixing aspects were studied. The effects of the specific impeller, the agitation speed during the coagulation and flocculation stages, and the absence or presence of baffles were evaluated in a six-place agitation system. The conventional impellers were replaced by the following types of propellers: Rushton, marine, A310 (Lightning), three flat blades, 45° inclined six blades, and conventional flat blade propeller. It was demonstrated that the appropriate coagulation-flocculation system is capable of diminishing the COD, the apparent color and the dissolved solids up to 40.6, 25.6 and 39.4%, respectively. The best results were observed when using BL-5086, guar gum, Niad II-3, Niad II-4 and locus beam gum. The impeller performance was highly dependent on the agitation speed for each fixed system. With respect to the mixing aspects, it was shown that the selection of the right propeller for the coagulation and flocculation stages is crucial in determining the quality of the treated water, as well as the quantity and quality of the residual sludges generated in the process.

Evaluation of the WHO helminth eggs criteria using a QMRA approach for the safe reuse of wastewater and sludge in developing countries

An analysis of the actual WHO recommendations to develop standards for the safe reuse of wastewater, excreta or sludge in agriculture using a quantitative microbial risk assessment (QMRA) is presented. The proposed values are defined using a risk-based model for Ascaris lumbricoides infection to assess the human risks associated with exposure to this pathogen from crops irrigated with polluted water, or from crops grown in biosolid-enriched soil. From the results it becomes evident that, with regard to helminth eggs, the WHO guidelines for wastewater reuse in agriculture seem more stringent than are needed in developing countries, while for the reuse of sludge they appear to be the opposite. Although more information is needed to confirm this conclusion, which was derived from a single piece of research, at the very least a more cautious approach is recommended when evaluating excreta or sludge for agricultural purposes in developing countries. Additionally, this work shows that the application of some barriers, other than wastewater and sludge treatment as suggested by WHO, can play an important role in controlling risks.

Regulation of fatty acid oxidation by adenosine at the level of its extramitochondrial activation.

Conditions for the conversion of palmitate into CO2 and acetoacetate by liver homogenates and isolated liver mitochondria are described. In this system, using liver homogenates, adenosine inhibited the conversion of palmitate into CO2 and acetoacetate. The inhibition was not observed if the homogenate was substituted by mitochondria or if palmitate was substituted by palmitoyl CoA or palmitoyl carnitine. Intraperitoneal injection of adenosine produced a marked decrease in the level of acetoacetate and β-hydroxybutyrate in plasma, without changing the concentration of serum free fatty acids. Thus, the nucleoside depressed in vivo the oxidation of long chain fatty acids in liver by inhibiting the extramitochondrial acyl CoA synthase(s). The paramount importance of the extramitochondrial activation of fatty acids as a key control in their oxidation and in the production of ketone bodies is discussed.

Performic acid for advanced wastewater disinfection.

The disinfection efficiency of performic acid (PFA) against various microbial contaminants has been studied in municipal secondary effluent. The study demonstrated that PFA provides rapid, efficient and safe disinfection, degrading both bacteria and viruses even at low doses. The resistance order starting from the most resistant microorganism is as follows: MS2-coliphages > DNA-coliphages > enterococci and Escherichia coli. PFA is also efficient in the elimination of Salmonella spp., Clostridium perfringens spores and Giardia cysts. The results showed that a PFA dose as low as 0.5-1 mg L(-1) with contact time of 10 min was efficient in achieving and maintaining for 72 h the disinfection level required for unrestricted agricultural water reuse (≤3 log units for faecal coliforms). However, the optimal dose will depend on the quality of wastewater. Regarding the formation of by-products during disinfection with PFA, very low amounts of hydrogen peroxide and organic per-acids were observed; active oxygen was not detected. The amounts of adsorbable organically bound halogens (AOX) compounds formed were significantly lower compared to the amounts generated during chlorine disinfection. This chlorine-free solution enables compliance with microbiological criteria for various water reuse applications and is already on the market for advanced disinfection.