Cascade utilization of water chestnut: recovery of phenolics, phosphorus, and sugars

Overgrowth of aquatic plants, such as water chestnut, has been reported as a regional problem in various areas. We proposed cascade utilization of water chestnut through the recovery of phenolics, phosphorus, and sugars. Phenolics were extracted using 50 g (wet weight) of biomass with 300 mL of acetone, methanol, or hot water, and the yields of total phenolics were 80.2, 56.2, and 49.7 mg?g^?1 dry weight of native biomass, respectively. The rate of eluted phosphorus in the phenolic extraction step was 8.6, 14.8, and 45.3 % of that in the native biomass, respectively, indicating that the use of polar organic solvents suppressed phosphorus elution at the phenolic extraction step. Extraction of phosphorus following the phenolic extraction was combined with alkaline pretreatment (1 % NaOH solution) of biomass for saccharification; 64.1 and 51.0 % of phosphorus in the native biomass were extracted using acetone and methanol for the phenolic extraction, respectively. Saccharification following the alkaline pretreatment showed that the glucose recovery rates were significantly increased (p?<?0.05) with the phenolic extraction step compared to alkaline pretreatment alone. This finding indicates that extraction of phenolics not only provides another useful material but also facilitates enzymatic saccharification.     

Synthetic olive mill wastewater treatment by Fenton’s process in batch and continuous reactors operation

Degradation of total phenol (TPh) and organic matter, (expressed as total organic carbon TOC), of a simulated olive mill wastewater was evaluated by the Fenton oxidation process under batch and continuous mode conditions. A mixture of six phenolic acids usually found in these agro-industrial wastewaters was used for this purpose. The study focused on the optimization of key operational parameters of the Fenton process in a batch reactor, namely Fe²⁺ dosage, hydrogen peroxide concentration, pH, and reaction temperature. On the assessment of the process efficiency, > 99% of TPh and > 56% of TOC removal were attained when [Fe²⁺] = 100 ppm, [H₂O₂] = 2.0 g/L, T = 30 °C, and initial pH = 5.0, after 300 min of reaction. Under those operational conditions, experiments on a continuous stirred-tank reactor (CSTR) were performed for different space-time values (τ). TOC and TPh removals of 47.5 and 96.9%, respectively, were reached at steady-state (for τ = 120 min). High removal of COD (> 75%) and BOD₅ (> 70%) was achieved for both batch and CSTR optimum conditions; analysis of the BOD₅/COD ratio also revealed an increase in the effluent’s biodegradability. Despite the high removal of lumped parameters, the treated effluent did not met the Portuguese legal limits for direct discharge of wastewaters into water bodies, which indicates that coupled chemical-biological process may be the best solution for real olive mill wastewater treatment.     

Reconstruction of the pollution history of alkylphenols (4-tert-octylphenol, 4-nonylphenol) in the Baltic Sea

This paper reports the reconstruction of the pollution history of 4-tert-octylphenol (OP) and 4-nonylphenol (NP) in the Baltic Sea. Alkylphenols are endocrine-disrupting compound and therefore toxic to aquatic organisms. Sediment cores were collected from regions with relatively stable sedimentation conditions. The cores were dated by the ²¹⁰Pb method. The OP and NP were determined using HPLC-FL. The highest inventory of these compounds was observed in the Gotland Deep (610 μg m² of NP and 47 μg m² of OP) and the lowest—on the slope of the Gdansk Deep (24 μg m² of NP and 16 μg m² of OP). Such spatial distribution was probably, among other factors, the result of the uplift of the sea floor. The pollution trends of OP and NP in sediments coincided with the following: (1) the beginnings of eutrophication (1960s/1970s of the twentieth century) and (2) strong increase in the areal extent and volume of hypoxia and anoxia in the Baltic (present century).     

酚类化合物在2-羧基苯甲酰基修饰的超高交联树脂上的吸附

合成了一种用来吸附和去除水溶液中酚类化合物的 2 羧基苯甲酰基修饰的超高交联吸附树脂 (ZH 0 1) ,并从动力学和吸附容量角度比较了XAD 4、AM 1和ZH 0 1分别吸附浓度为 80 0mg/L苯酚的情况。实验结果表明 ,ZH 0 1吸附剂有利于吸附苯酚、对甲苯酚和对硝基苯酚之类的酚类化合物。动力学和热力学研究都得到了相同的结果 :ZH 0 1对苯酚和对甲苯酚吸附是化学吸附的过渡状态 ,而对对硝基苯酚的吸附是一种物理吸附过程 ,并且显示了ZH 0 1表面均孔特性。苯酚在ZH 0 1上的小柱吸附研究表明了吸附穿透容量和总吸附量分别为 2 .38mmol/g和 3.0 5mmol/g ,溶剂甲醇对吸附在ZH 0 1上苯酚的脱附效果较好。     

Analysis of Herbicide Krovar I™ by Liquid Chromatography with Atmospheric Pressure Chemical Ionization Mass Spectrometry

Abstract

A simple, very efficient method is presented for routine analysis of herbicide Krovar I? (active components bromacil and diuron) in water and soil samples. Water samples were extracted by liquid–liquid extraction with dichloromethane (DCM) as extraction solvent. For soil samples two different extraction techniques were compared: microwave-assisted solvent extraction and a shaking technique using a platform shaker. Extracts were analyzed by high performance liquid chromatography using a water:methanol gradient. Liquid chromatography was coupled with atmospheric pressure chemical ionization mass spectrometry (LC-APCI-MS) for quantification of bromacil and diuron. Optimization of the APCI-MS was done by using standards in the flow injection analysis mode (FIA). Method detection limit for liquid samples for bromacil is 0.04 µg L^?1 and for diuron 0.03 µg L^?1. Method detection limit for soil samples is 0.01 µg g^?1 dry weight for both compounds. Results of analysis of field samples of water and soil are also presented.     

Sequential treatment of olive oil mill wastewater with adsorption and biological and photo-Fenton oxidation

Olive oil mill wastewater (OMWW), a recalcitrant pollutant, has features including high phenolic content and dark color; thereby, several chemical or physical treatments or biological processes were not able to remediate it. In this study, the treatment efficiencies of three treatments, including adsorption, biological application, and photo-Fenton oxidation were sequentially evaluated for OMWW. Adsorption, biological treatment, and photo-Fenton caused decreasing phenolic contents of 48.69 %, 59.40 %, and 95 %, respectively. However, after three sequential treatments were performed, higher reduction percentages in phenolic (total 99 %) and organic contents (90 %) were observed. Although the studied fungus has not induced significant color reduction, photo-Fenton oxidation was considered to be an attractive solution, especially for color reduction. Besides, toxicity of OMWW treatment was significantly reduced.     

Utilization of water chestnut for reclamation of water environment and control of cyanobacterial blooms

Overgrowth of water chestnut (Trapa spp.) is a regional problem throughout Asia and North America because of waterway blockage and water fouling upon decomposition. In the present study, we investigated the potential of water chestnut to control cyanobacterial blooms, via a high content of phenolic compounds. In addition, we assessed the impact of biomass harvesting and crude extract application on nutrient balance. We showed that the floating parts of water chestnut contained high concentrations of total phenolics (89.2 mg g^?1 dry weight) and exhibited strong antioxidant activity (1.31 mmol g^?1 dry weight). Methanol-extracted phenolics inhibited growth of Microcystis aeruginosa; the half maximal effective concentration (EC₅₀) of the extracted phenolics was 5.8 mg L^?1, which was obtained from only 103 mg L^?1 of dry biomass (the floating and submerged parts). However, the crude extracts also added important quantities of nitrogen, phosphorus, and potassium (1.49, 1.05, and 16.3 mg g^?1, respectively; extracted dry biomass weight basis); therefore, in practice, nutrient removal before and/or after the extraction is essential. On the other hand, biomass harvesting enables recovery of nitrogen, phosphorus, and potassium from the water environment (23.1, 2.9, and 18.7 mg g^?1, respectively; dry biomass weight basis). Our findings indicate that water chestnut contains high concentrations of phenolics and exhibits strong antioxidant activity. Utilization of these resources, including nutrients, will contribute to reclamation of the water environment, and also to disposal of wet biomass.     

Assessment of the allelopathic effect of leaf and seed extracts of Canavalia ensiformis as postemergent bioherbicides: A green alternative for sustainable agriculture

The herbicidal potential of aqueous extracts prepared from leaves and seeds of Canavalia ensiformis was tested by applying them postemergence to the crop weeds Ipomoea grandifolia and Commelina benghalensis. Considering the possible objective of using this bioherbicide on soybean fields, the extracts were also tested for deleterious effects on both transgenic and conventional soybean (Glycine max). In addition, the concentrations of four phenolic compounds and alkaloids with allelopathic properties in these extracts were estimated by high-performance liquid chromatography. The seed extract at concentrations of 25 g L^?1 and 50 g L^?1 was the most efficient postemergent bioherbicide. By applying these extracts, the development of the weed seed was progressively hindered until no recovery was observed. The application of 3.5 mL of crude extract on a plant that takes 30 days after germination of the seed to develop is sufficient for full control of the species within 5 days. Since both Ipomoea grandifolia and Commelina benghalensis are broadleaf dicotyledons, it is possible that other species with these characteristics can also be controlled or suffer the same effects under the action of the seed extract, if the same volume and mode of application are used. The selectivity of the treatments with 25 g L^?1 and 50 g L^?1 was assessed on transgenic and conventional cultivars. The treatments did not visibly affect the soybean cultivars, which developed normally during the observation period that continued up to 15 days after the death of the weeds.     

Identification and source apportionment of polycyclic aromatic hydrocarbons in ambient air particulate matter of Riyadh, Saudi Arabia

In an effort to assess the occurrence and sources of polycyclic aromatic hydrocarbons (PAHs) in the ambient air of Riyadh, Saudi Arabia, PM₁₀ samples were collected during December 2010. Diagnostic PAH concentration ratios were used as a tool to identify and characterize the PAH sources. The results reflect high PM₁₀ and PAH concentrations (particulate matter (PM)?=?270–1,270 μg/m³). The corresponding average PAH concentrations were in the range of 18?±?8 to 1,003?±?597 ng/m³ and the total concentrations (total PAHs (TPAHs) of 17 compounds) varied from 1,383 to 13,470 ng/m³ with an average of 5,871?±?2,830 ng/m³. The detection and quantification limits were 1–3 and 1–10 ng/ml, respectively, with a recovery range of 42–80 %. The ratio of the sum of the concentrations of the nine major non-alkylated compounds to the total (CPAHs/TPAHs) was 0.87?±?0.10, and other ratios were determined to apportion the PM sources. The PAHs found are characteristic for emissions from traffic with diesel being a predominant source.     

Occurrence, distribution, and sources of six phenolic endocrine disrupting chemicals in the 22 river estuaries around Dianchi Lake in China

The objectives of this study are to track the occurrence, distribution, and sources of phenolic endocrine disrupting compounds (EDCs) in the 22 rivers around Dianchi Lake in China, to estimate the input and output amounts of phenolic EDCs in the water system, and to provide more comprehensive fundamental data for risk assessment and contamination control of phenolic EDCs in aquatic environment. Six phenolic EDCs were systematically evaluated in water and surface sediment in the estuaries of those rivers. The water and sediment samples were preconcentrated by solid-phase extraction system and microwave-assisted extraction system, respectively. Phenolic EDCs were analyzed by GC-MS (Thermo Fisher Scientific, USA) after derivatization. Phenolic EDCs were found ubiquitously in the aquatic environment. The total concentrations ranged from 248 to 4,650 ng/L in water, and 113 to 3,576 ng/g dry weight in surface sediment. The residue amount of phenolic EDCs in Dianchi Lake was 258 kg/a. Concentrations of the phenolic EDCs in the Lake decreased with increase in distance to the estuaries of those rivers which run through urban and industrial areas. The rivers seriously contaminated by phenolic EDCs were Xin River, Yunliang River, Chuanfang River, Cailian River, Jinjia River, Zhengda River, and Daqing River which run through the old area of Kunming City. Satisfying correlations were observed between the concentrations of the target compounds in water and in surface sediment. NP1EO, NP2EO, and BPA were identified as the three predominant phenolic EDCs. There were significant correlations between phenolic EDCs and many basic water quality parameters. Urban and industrial areas are the major contributors for phenolic EDCs, especially in Kunming City. Compositional profiles of phenolic EDCs in surface sediment were similar to those in river water. The concentrations of phenolic EDCs in the rivers located in the northwest part of the valley were very high, and posed a potential risk to aquatic organisms and even human. The concentrations of NP2EO, NP1EO, and BPA were at moderate levels of other areas. The basic water quality parameters (TOC, TN, DO, and pH) play important roles on the distribution, fate, and behavior of phenolic EDCs in the valley.     

Olive tree, Olea europaea L., leaves as a bioindicator of atmospheric PCB contamination

Olive tree leaf samples were collected to investigate their possible use for biomonitoring of lipophilic toxic substances. The samples were analyzed for 28 polychlorinated biphenyls (PCB) congeners. Twelve congeners were detected in the samples. PCB-60, 77, 81, 89, 105, 114, and 153 were the most frequently detected congeners ranging from 32 % for PCB-52 to 97 % for PCB-81. Σ₁₂PCBs concentration varied from below detection limit to 248 ng/g wet weight in the sampling area, while the mean congener concentrations ranged from 0.06 ng/g (PCB-128?+?167) to 64.2 ng/g wet weight (PCB-60). Constructed concentration maps showed that olive tree leaves can be employed for the estimation of spatial distrubution of these congeners.     

Effects of allelochemical extracted from water lettuce (Pistia stratiotes Linn.) on the growth, microcystin production and release of Microcystis aeruginosa

This study explored the optimisation of a method of extracting allelochemicals from Pistia stratiotes Linn., identified the optimal dose range for the allelochemicals’ anti-algal effect and investigated their impact on the growth of Microcystis aeruginosa, as well as the production and release of microcystin-LR (MC-LR). Based on measured changes in algal cell density and chlorophyll a (Chl-a) content, the allelochemicals were confirmed to have the strongest anti-algal effect with the lowest half-effect concentration of 65 mg L^?1 when they were extracted using ethyl acetate as the extraction solvent, 1:20 g mL^?1 as the extraction ratio and 1 h as the extraction time. The allelochemicals extracted from P. stratiotes using this optimal method exhibited the strongest inhibitory effect on the growth of algae when used within a dose range of 60–100 mg L^?1; the relative inhibitory ratio reached 50–90 %, and Chl-a content reduced 50–75 % in algae cell cultures within 3–7 days. In addition, the extracted allelochemical compounds demonstrated no significant impact on the extracellular release of MC-LR during the culturing period. The amount of intracellular MC-LR per 10⁶ algal cells increased depending on the increasing dose of allelochemicals from P. stratiotes after 7 days of culturing and maintained stability after 16 days. There was no increase in the total amount of MC-LR in the algal cell culture medium. Therefore, the application of allelochemicals from P. stratiotes to inhibit M. aeruginosa has a high degree of ecological safety and can be adopted in practical applications for treating water subjected to algae blooms because the treatment can effectively inhibit the proliferation of algal cells without increasing the release of cyanotoxin.     

Determination of phenols and pharmaceuticals in municipal wastewaters from Polish treatment plants by ultrasound-assisted emulsification–microextraction followed by GC–MS

A method combining ultrasound-assisted emulsification–microextraction (USAEME) with gas chromatography–mass spectrometry (GC–MS) was developed for simultaneous determination of four acidic pharmaceuticals, ibuprofen, naproxen, ketoprofen, and diclofenac, as well as four phenols, 4-octylphenol, 4-n-nonylphenol, bisphenol A, and triclosan in municipal wastewaters. Conditions of extraction and simultaneous derivatization were optimized with respect to such aspects as type and volume of extraction solvent, volume of derivatization reagent, kind and amount of buffering salt, location of the test tube in the ultrasonic bath, and extraction time. The average correlation coefficient of the calibration curves was 0.9946. The LOD/(LOQ) values in influent and effluent wastewater were in the range of 0.002–0.121/(0.005–0.403) μg L^?1 and 0.002–0.828/(0.006–2.758) μg L^?1, respectively. Quantitative recoveries (≥94 %) and satisfactory precision (average RSD 8.2 %) were obtained. The optimized USAEME/GC–MS method was applied for determination of the considered pharmaceuticals and phenols in influents and treated effluents from nine Polish municipal wastewater treatment plants. The average concentration of acidic pharmaceuticals in influent and effluent wastewater were in the range of 0.06–551.96 μg L^?1 and 0.01–22.61 μg L^?1, respectively, while for phenols were in the range of 0.03–102.54 μg L^?1 and 0.02–10.84 μg L^?1, respectively. The removal efficiencies of the target compounds during purification process were between 84 and 99 %.     

Simultaneous determination of estrogenic odorant alkylphenols,chlorophenols, and their derivatives in water using online headspace solid phase microextraction coupled with gas chromatography-mass spectrometry

A simple online headspace solid-phase microextraction (HS-SPME) coupled with the gas chromatography-mass spectrometry (GC-MS) method was developed for simultaneous determination of trace amounts of nine estrogenic odorant alkylphenols and chlorophenols and their derivatives in water samples. The extraction conditions of HS-SPME were optimized including fiber selection, extraction temperature, extraction time, and salt concentration. Results showed that divinylbenzene/Carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber was the most appropriate one among the three selected commercial fibers, and the optimal extraction temperature, time, and salt concentration were 70 °C, 30 min, and 0.25 g/mL, respectively. The developed method was validated and showed good linearity (R ²?>?0.989), low limit of detection (LOD, 0.002–0.5 μg/L), and excellent recoveries (76–126 %) with low relative standard deviation (RSD, 0.7–12.9 %). The developed method was finally applied to two surface water samples and some of these target compounds were detected. All these detected compounds were below their odor thresholds, except for 2,4,6-TCAS and 2,4,6-TBAS wherein their concentrations were near their odor thresholds. However, in the two surface water samples, these detected compounds contributed to a certain amount of estrogenicity, which seemed to suggest that more attention should be paid to the issue of estrogenicity rather than to the odor problem.     

Valorization of treated olive mill wastewater in fertigation practice

Olive mill wastewater (OMW) brings about a major environmental problem in Tunisia as well as in the other Mediterranean countries. Its strong organic load and its toxicity due to the presence of complex phenolic compounds have dire effects when applied to soil. To overcome this difficulty, the OMW pretreatment was investigated in the present work using the Fenton oxidation reaction with zero-valent iron. Then, this pretreated wastewater was valorized in fertigation practice. The effects of the addition of different concentrations of both treated and raw OMW on soil and cropping system were investigated. The treatment by Fenton oxidation with zero-valent iron could reduce 50 % of COD and decrease 53 % of phenolic compounds. OMW application had a temporary effect on the soil pH and EC. The results showed that the evolution of soil pH and EC was related to the organic matter of the soil which depends on the spread concentrations of raw or treated OMW. After 15-day incubation period, the soil pH and EC tended to stabilize and return to the control level. Moreover, this stabilization is faster in treated OMW than that in raw OMW especially for concentrations as high as 3 and 4 %. Plants cultivated with treated OMW showed an increase in their germination. The results pointed an improvement in the stem length of plants which is almost similar to that of the control for both pea and tomato, especially for high concentrations of 3 and 4 %.     

Extraction procedure optimization for perfluorooctane sulfonate and perfluorooctanoic acid in food packaging determination by LC-MS/MS

This research aimed to optimize the extraction method parameters for sample pretreatment and determine the levels of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) contamination in food packaging made of paper. Techniques used were pressurized liquid extraction (PLE) followed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Influence parameters of PLE were carefully evaluated for extracted concentration of samples in low level (ng g^?1). The study found that the optimal conditions for PLE were 30 min static extraction time with a flush volume of 100% cell volume and one extraction cycle at 80°C and 1,000 psi. The extraction technique validated the absolute recovery from PFOS and PFOA fortified control samples at three different levels (5, 50, and 200 ng g^?1), with seven repeats at each fortification level. The average recoveries were 79% or higher, with relative standard deviation (RSD) less than 11%. Optimization of the PLE method was established based on recovery data, accuracy, precision, and repeatability of the method. Using optimal PLE technique, PFOS and PFOA were extracted from 34 food-packaging samples collected in Thailand. PFOS and PFOA were detected in all kinds of collected samples, with average concentrations of 4.89 and 2.87 ng g^?1, respectively. The concentrations of PFOS and PFOA were highest in fast-food container samples: 36.99 and 9.99 ng g^?1, respectively.     

Fast determination of sulfonamides and their acetylated metabolites from environmental water based on magnetic molecularly imprinted polymers

Group-selective magnetic molecularly imprinted polymers (MMIPs) that can extract four widely used sulfonamide antibiotics and their acetylated metabolites from environmental water were synthesized in this study. The MMIPs with saturation magnetization value of 16.7 emu g^-1 could be separated from the environmental water samples easily by the application of an adscititious magnetic field, reducing the time consumption of pretreatment. The extraction conditions were evaluated, and optimal extraction conditions were as follows: extraction time, 25 min; amount of polymers, 90 mg; washing solvent, 30 % methanol aqueous solution; and elution solvent, methanol–acetic acid (95:5, v/v). The target analytes were detected by liquid chromatography–tandem mass spectrometry, and the detection limits of the method are in the range of 0.38–1.32 ng L^-1. The relative standard deviations of intra- and inter-day are in the range of 1.3–6.8 % and 1.7–9.1 %, respectively. The proposed method is suitable for the analysis of environmental water samples.     

Trace analysis of parabens preservatives in drinking water treatment sludge,treated, and mineral water samples

Parabens have been widely used as antimicrobial agents, mainly in food products, pharmaceuticals, and cosmetics. Although they are known as safe preservatives, they also cause some harm to human health, which has been discussed lately. Therefore, the aim of this study was to evaluate the occurrence of nine parabens (including isomers) in mineral and drinking waters, besides in drinking water treatment sludge (DWTS) samples with determination by liquid chromatography tandem mass spectrometry (LC-MS/MS). Both methods solid phase extraction (SPE) and QuEChERS were validated. Calibration curves showed a correlation coefficient of 0.99 for all compounds. LOQ values ranged from 0.04 to 4 μg L^?1 in aqueous matrices and from 5 to 500 ng g^?1 in DWTS. Recoveries between 70 and 115% were reached with RSD below 20% for all compounds in SPE whereas recoveries between 62 and 119% were found with RSD below 20% for almost all compounds in QuEChERS. Matrix effect had low values (<?20%); it was only above 20% for methylparaben in the SPE and for pentylparaben in the QuEChERS. Using a quick and simple extraction procedures with SPE, QuEChERS, and LC-MS/MS analyses, these methods proved to be selective and sensitive. They were successfully applied to real samples (treated water, mineral water, and sludge), and methylparaben was detected at concentration levels below 0.242 μg L^?1 in mineral and treated water samples and 10 ng g^?1 in DWTS samples.     

Rapid metal extractability tests from polluted mining soils by ultrasound probe sonication and microwave-assisted extraction systems

Ultrasonic probe sonication (UPS) and microwave-assisted extraction (MAE) were used for rapid single extraction of Cd, Cr, Cu, Ni, Pb, and Zn from soils polluted by former mining activities (Mónica Mine, Bustarviejo, NW Madrid, Spain), using 0.01 mol L^?1 calcium chloride (CaCl₂), 0.43 mol L^?1 acetic acid (CH₃COOH), and 0.05 mol L^?1 ethylenediaminetetraacetic acid (EDTA) at pH 7 as extracting agents. The optimum extraction conditions by UPS consisted of an extraction time of 2 min for both CaCl₂ and EDTA extractions and 15 min for CH₃COOH extraction, at 30% ultrasound (US) amplitude, whereas in the case of MAE, they consisted of 5 min at 50 °C for both CaCl₂ and EDTA extractions and 15 min at 120 °C for CH₃COOH extraction. Extractable concentrations were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). The proposed methods were compared with a reduced version of the corresponding single extraction procedures proposed by the Standards, Measurements and Testing Programme (SM&T). The results obtained showed a great variability on extraction percentages, depending on the metal, the total concentration level and the soil sample, reaching high values in some areas. However, the correlation analysis showed that total concentration is the most relevant factor for element extractability in these soil samples. From the results obtained, the application of the accelerated extraction procedures, such as MAE and UPS, could be considered a useful approach to evaluate rapidly the extractability of the metals studied.