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This study is focused on the utilization of waste microalgal sludge (MS) from microalgal extraction and its potential as an electrode material. The MS was activated under N 2 at high temperature for conversion to biochar (MSB). In addition, cobalt (Co; metal hydroxide) and chitosan were used as a mediator for electron transfer by immobilization on MSB (MSB/Co/chitosan). Through analysis of the surface and components of the MSB/Co/chitosan, it was shown that Co and chitosan were properly synthesized with MSB. The enzymatic fuel cell (EFC) system successfully obtained a power density of 3.1 mW cm −2 and a current density of 9.7 mA cm −2 . In addition, the glucose biosensors applied with the developed electron transfer mediator showed a sensitivity of 0.488 mA mM −1  cm −2 . [ABSTRACT FROM AUTHOR]

In this study single-chamber microbial electrolysis cells (MECs) were applied to treat cheese whey (CW), an industrial by-product, and recover H 2 gas. Firstly, this substrate was fed directly to the MEC to get the initial feedback about its H 2 generation potential. The results indicated that the direct application of CW requires an adequate pH control to realize bioelectrohydrogenesis and avoid operational failure due to the loss of bioanode activity. In the second part of the study, the effluents of anaerobic (methanogenic) digester and hydrogenogenic (dark fermentative H 2 -producing) reactor utilizing the CW were tested in the MEC process (representing the concept of a two-stage technology). It turned out that the residue of the methanogenic reactor – with its relatively lower carbohydrate- and higher volatile fatty acid contents – was more suitable to produce hydrogen bioelectrochemically. The MEC operated with the dark fermentation effluent, containing a high portion of carbohydrates and low amount of organic acids, produced significant amount of undesired methane simultaneously with H 2 . Overall, the best MEC behavior was attained using the effluent of the methanogenic reactor and therefore, considering a two-stage system, methanogenesis is an advisable pretreatment step for the acidic CW to enhance the H 2 formation in complementary microbial electrohydrogenesis. [ABSTRACT FROM AUTHOR]

The advanced treatment of polluted liquid streams containing traces of pharmaceutical compounds is a major issue, since more and more effluents from pharma labs and wastewaters containing the excretions of medically treated humans and animals are discharged in the conventional wastewater treatment plants without previous effective treatments. Ibuprofen is a widely used non-steroidal anti-inflammatory drug (NSAID), which explains why it is found in wastewaters so often. In this paper, the removal of IBP from simulated water streams was investigated by using a lab-scale experimental device, consisting of a batch reactor equipped with a lamp emitting monochromatic UV light at a fixed wavelength (254 nm) and various intensities. Three sets of experiments were carried out: the first to study IBP concentration as a function of time, at different volumes of treated solutions ( V = 10-30 mL); the second to explore the effect of pH on IBP degradation as a function of time (pH = 2.25-8.25) and the third to evaluate the effect of different UV light intensities on IBP degradation ( E = 100-400 mJ m). The IBP initial concentration ( IBP ) was varied in the range 30-60 mg L. The results obtained show that the concentration of IBP decreases along with treatment time, with a negative effect of the treated volume, i.e. smaller volumes, such as lower liquid heights, are more easily degraded. Moreover, the higher the pH, the better the IBP degradation; actually, when pH increases from 2.25 to 6.6 and 8.25, the IBP concentration, after an hour of treatment, decreases respectively to 45, 34 and 27 % of its initial value. In addition, as the intensity of light increases from 100 to 400 mJ m, the IBP concentration decreases to 34 % of its initial value. A reaction scheme is put forward in the paper, which well describes the effects of volume, pH and light intensity on the IBP degradation measured experimentally. Moreover, the IBP degradation by-products have been identified. [ABSTRACT FROM AUTHOR]

We used batch-type experiments to study F sorption/desorption on a forest soil, a vineyard soil, pyritic material, granitic material, finely and coarsely ground mussel shell, mussel shell calcination ash, oak wood ash, pine-sawdust, slate processing fines, and three different mixtures that included three components: sewage sludge, mussel shell ash, and calcined mussel shell or pine wood ash. The three waste mixtures, forest soil, pyritic material, and shell ash showed high sorption capacity (73-91 % of added F) and low desorption, even when 100 mg F L was added. All these materials (and to a lower extent wood ash) could be useful to remove F from polluted media (as certain soils, dumping sites, and contaminated waters). The vineyard soil, the granitic material, mussel shell, slate fines, and pine-sawdust were less effective in F removal. In most cases, sorption data fitted better to the Freundlich than to the Langmuir equation. These results can be useful to program the correct management of the soils, by-products, and waste materials assayed, mostly in situations where F concentrations are excessive and F removal should be promoted. [ABSTRACT FROM AUTHOR]

The viability of using two waste materials, water treatment sludge (WTS) and fly ash (FA), for developing sustainable masonry units has been previously investigated in terms of strength but the important aspect of durability against wetting.drying (w.d) cycles has yet to be studied. A study on durability against w.d cycles, an important parameter for service life design of the sustainable masonry units, is investigated in this paper. The liquid alkaline activator (L) was a mixture of sodium silicate (Na2SiO3) and sodium hydroxide (NaOH), and a high calcium fly ash (FA) was used as a precursor. The results of cyclic w.d test indicate that the WTS.FA geopolymer manufactured with an optimum ingredient (L.FA = 1.6, Na2SiO3.NaOH = 90.10) and at an optimum heat condition of 85¡ÆC for 72 h can be used as durable bearing masonry units; i.e., the compressive strength is greater than 12 MPa after 12 w.d cycles. For this optimum ingredient, the w.d cycle strength, qu(w-d) at heat temperatures between 65 and 95°C and durations between 24 and 120 h was found to be mainly dependent upon the initial soaked (without w.d cycle) strength qu0, and the normalized strength qu(w-d)/qu0 versus number of w.d cycles relationship expresses as a logarithm function. This relationship facilitates a mix design to attain the required strength at a target service life, which is very useful for civil engineering practitioners and researchers alike. It is evident from this research that portland cement is not a suitable cementing agent to manufacture WTS masonry units because alum in WTS retards the cement hydration, unlike a geopolymer binder, which was proven to be suitable. Compared with a traditional clay.cement sample at the same initial soaked strength, the WTS.FA geopolymer sample exhibits higher durability. This indicates that the WTS.FA geopolymer masonry units have a longer service life than clay.cement masonry units, which is typically used in many countries. This research enables WTS traditionally destined for landfill to be used in a sustainable manner as an aggregate in geopolymer masonry units, which is significant from engineering, economical, and environmental perspectives. [ABSTRACT FROM AUTHOR]

Discharge of textile wastewaters (WW) to municipal wastewater treatment plants (MWWTPs) entails the presence of colour in the final effluent. It causes a negative impact on the environment and, additionally, hinders an efficient disinfection by UV lamps. In this work, a combined process consisting of the addition of powdered activated carbon (PAC) to a sequencing batch reactor was studied. The main objective was to reduce WW colour in order to obtain transmittance values in the final effluent above 60%, measured at a wavelength of 254?nm, with the aim of ensuring disinfection with UV lamps. Experiments were performed with both simulated wastewater (SWW) including the azo dye Reactive Black 5 and WW from a MWWTP receiving discharges from textile mills. Biosorption increased the transmittance of the effluent around 25% for SWW and 24% for WW, in comparison with the values measured in the influent. The PAC concentrations for the achievement of a value of 60% in the transmittance of the treated water were 250 and 400?mg/L for the simulated effluent and for the WW, respectively. PAC had to be periodically added in order to cover its loss in the waste sludge. [ABSTRACT FROM PUBLISHER]

This study was undertaken to evaluate the potential use of electrolysis process for waste sludge stabilization in decentralization practices by focusing on the operating parameters such as sludge composition, detention time, and electric voltage. The laboratory batch scale results show that the sludge extracted from a packed bed biofilm reactor can reach the minimum concentration of 659 mg/L volatile suspended solids (VSS) merely within 5 h detention time at an applied voltage of 2 V, whereas the most identical level is obtained from activated sludge by 7 h with 3.6 V. The soluble COD in the supernatant phase of the former process would be increased to 297 mg/L by means of 27% VSS reduction. The economical pre-estimation indicates that electrolysis is more sustainable if stand as a preconditioning stage of biological digestion by 70% capital and operating cost reduction. This configuration can also cause occupying 54% lesser footprint area of aerobic digestion with total average reduction of 56% VSS within 77 h. The biological assay on digested product was also determined with reference to the growth ofPhragmitessp. plant. This study recommends the electrolysis-pretreated conditioning waste sludge followed by aerobic digestion incorporating with attached growth biological systems as a valuable process in decentralization. [ABSTRACT FROM PUBLISHER]

Aluminium-based water treatment sludge was used as a coagulant for removing/recovering phosphate from the effluent of upflow anaerobic sludge blanket (UASB) reactor treating municipal wastewater. The effect of three variables, namely sludge dose, initial pH and fresh coagulant (poly-aluminium chloride, PAC1) dose was studied using response surface methodology. About 87% phosphate removal could be obtained at the optimum conditions of sludge dose 13.8 g/L, initial pH 6, and fresh PAC1 dose 5.8 mg Al/L. In order to achieve a similar phosphate removal, a dose in the range of 30-40 mgAl/L of fresh PAC1 was required. The results suggest that water treatment sludge can be reused as a coagulant for post-treatment of UASB reactor effluent treating municipal wastewater and can be considered as a promising alternative for removing phosphate which can substantially reduce the consumption of fresh PAC1. The sludge generated during this process could potentially be used in land application which results in recycling of phosphate. [ABSTRACT FROM AUTHOR]

ABSTRACT Organic content and nutrients from dairy effluent by immobilized Chlorella pyrenoidosa and Euglena gracilis were removed in both open and closed systems. Biochemical constituents viz, carbohydrates, lipids, and proteins were analyzed to assess the changes in their proximate composition in both the systems for both species. Euglena gracilis has a high lipid content of 11% at the end of 7 days of cultivation period compared and to C. pyrenoidosa resulted in 7% at the end of 10 days, respectively. Whereas protein content of Chlorella sp . was found to be higher at 44% compared to 29% of Euglena sp. A significant increase was also observed in carbohydrates in C. pyrenoidosa at the end of 10 days. Whilst NH4+-N was completely removed by immobilized Chlorella sp ., it was reduced by 96% compared to Euglena sp. Further, 98% PO43−-P removal was achieved with immobilized cultures of both species in two modes of operation. Biological oxygen demand and chemical oxygen demand were observed in the range of significant decrease (~80%-96%) by this approach. © 2014 Curtin University of Technology and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In this study, porous suspended ceramsite with a specific density close to that of water was prepared by high-temperature calcination using fly ash, feldspar, calcite, fired talc and kaolin as the raw materials. The ceramsite was modified by activated carbon/Fe3O4magnetic composites. The optimum modification conditions determined by methylene blue adsorption experiment were: KOH/glucose ratio of 1.5:1, carbonization temperature of 400°C, activation temperature of 850°C, activation time of 1 h, and Fe3O4/KOH+glucose ratio of 1:10. The results demonstrated that the adsorption capacity of the modified ceramsite for methylene blue was significantly higher than that of the unmodified ones. The presence of the composites did not lead to significant decrease in the mechanical properties of the modified ceramsite. Moreover, the modified ceramsite showed good resistance towards acid and alkali. The modified ceramsite can be used as biocarrier and adsorbent for a wide range of contaminants in water and can subsequently be removed from the medium by a simple magnetic procedure. [ABSTRACT FROM PUBLISHER]

Copyright of Industria Textila is the property of Institutul National de Cercetare-Dezvoltare pentru Textile si Pielarie and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Recently, the reuse of waste activated sludge to produce short-chain fatty acids (SCFA) has attracted much attention. However, the influences of sludge characteristics, especially polyhydroxyalkanoates (PHA) and Gram-staining bacteria, on SCFA production have seldom been investigated. It was found in this study that during sludge anaerobic fermentation not only the fermentation time but also the SCFA production were different between two sludges, which had different PHA contents and Gram-negative bacteria to Gram-positive bacteria (GNB/GPB) ratios and were generated respectively from the anaerobic/oxic (AO) and aerobic/extended-idle (AEI) biological phosphorus removal processes. The optimal fermentation time for the AEI and AO sludges was respectively 4 and 8 d, and the corresponding SCFA production was 304.6 and 231.0 mg COD/g VSS (volatile suspended solids) in the batch test and 143.4 and 103.9 mg COD/g VSS in the semicontinuous experiment. The mechanism investigation showed that the AEI sludge had greater PHA content and GNB/GPB ratio, and the increased PHA content accelerated cell lysis and soluble substrate hydrolysis while the increased GNB/GPB ratio benefited cell lysis. Denaturing gradient gel electrophoresis profiles revealed that the microbial community in the AEI sludge fermentation reactor was dominated by Clostridium sp., which was reported to be SCFA-producing microbes. Further enzyme analyses indicated that the activities of key hydrolytic and acids-forming enzymes in the AEI sludge fermentation reactor were higher than those in the AO one. Thus, less fermentation time was required, but higher SCFA was produced in the AEI sludge fermentation system. [ABSTRACT FROM AUTHOR]

Fruit and vegetable wastes produced in astronomical quantities from food processing and agriculture industries often cause nuisance in municipal landfills owing to their high biodegradability. Biosorption by these waste-based adsorbents can be used as a cost effective and efficient technique for the removal of toxic heavy metals and dyes from wastewater. Recently, many papers claiming the feasible use of these biosorbents for water decontamination, treatment of industrial and agricultural wastewater and valuable metal recovery have been published. The organic waste-based adsorbents, characterized by good uptake capacity and rapid kinetics are expected to be economically and ecologically viable. This paper presents a judicious and pragmatic review depicting the key advances in implications of the fruit and vegetable wastes in pollution mitigation, the underlying mechanisms, major challenges and the future implementations. This compilation is expected to provide an impetus to the bioremediation research and promote green technology. [ABSTRACT FROM AUTHOR]

Conservation and preservation of freshwater is increasingly becoming important as the global population grows. Presently, enormous volumes of freshwater are used to mix concrete. This paper reports experimental findings regarding the feasibility of using treated effluents as alternatives to freshwater in mixing concrete. Samples were obtained from three effluent sources: heavy industry, a palm-oil mill and domestic sewage. The effluents were discharge into public drain without danger to human health and natural environment. Chemical compositions and physical properties of the treated effluents were investigated. Fifteen compositional properties of each effluent were correlated with the requirements set out by the relevant standards. Concrete mixes were prepared using the effluents and freshwater to establish a base for control performance. The concrete samples were evaluated with regard to setting time, workability, compressive strength and permeability. The results show that except for some slight excesses in total solids and pH, the properties of the effluents satisfy the recommended disposal requirements. Two concrete samples performed well for all of the properties investigated. In fact, one sample was comparatively better in compressive strength than the normal concrete; a 9.4% increase was observed at the end of the curing period. Indeed, in addition to environmental conservation, the use of treated effluents as alternatives to freshwater for mixing concrete could save a large amount of freshwater, especially in arid zones. [Copyright &y& Elsevier]

Ultraviolet (UV) filters are xenobiotic compounds that can enter the environment through the liquid effluent of wastewater treatment plants (WWTPs) and through adsorption in the sludge by-product because of their high hydrophobicity, as the sludge is subsequently applied as a fertiliser. A solid-state treatment of WWTP sludge with the white-rot fungus Trametes versicolor is reported in the present work as a feasible method for UV filter degradation, with reductions ranging from 87% in the case of 3-(4′-methylbenzylidene) camphor (4-MBC) to 100% for benzophenone-3 (BP3) and its metabolite 4,4′-dihydroxybenzophenone (4DHB). This study represents a first step in the development of a future fungal treatment for UV filters; thus, it is essential to prove that elimination is due only to the action of the fungus and not that of other microorganisms. To this end, the sludge was sterilised prior to fungal treatment. Biological assays indicate that T. versicolor readily eliminates oestrogenic activity, although it may be inefficient at eliminating other compounds, including some with dioxin-like activity. Degradation studies of 4-MBC in liquid media were also performed, and complete removal was achieved in less than 24 h. The main metabolites were identified, and the first steps of the transformation pathway were elucidated: a mono- or di-hydroxylation by cytochrome P450 and a subsequent conjugation with a pentose. None of 4-MBC transformation products was found to be responsible for increased dioxin-like activity in the sludge. [Copyright &y& Elsevier]

The electro-Fenton treatment of sulfachloro-pyridazine (SCP), a model for sulfonamide antibiotics that are widespread in waters, was performed using cells with a carbon-felt cathode and Pt or boron-doped diamond (BDD) anode, aiming to present an integral assessment of the kinetics, electrodegradation byproducts, and toxicity evolution. H2O2 electrogeneration in the presence of Fe2+ yielded •OH in the solution bulk, which acted concomitantly with •OH adsorbed at the anode (BDD(•OH)) to promote the oxidative degradation of SCP (kabs,SCP = (1.58 ± 0.02) × 109 M-1 s-1) and its byproducts. A detailed scheme for the complete mineralization was elucidated. On the basis of the action of •OH onto four different SCP sites, the pathways leading to total decontamination includes fifteen cyclic byproducts identified by HPLC and GC-MS, five aliphatic carboxylic acids, and a mixture of Cl-, SO42-, NH4+, and NO3- that accounted for 90-100% of initial Cl, S, and N. The time course of byproducts was satisfactorily correlated with the toxicity profiles determined from inhibition of Vibrio fischeri luminescence. 3-Amino-6-chloropyridazine and p-benzoquinone were responsible for the increased toxicity during the first stages. Independent electrolyses revealed that their toxicity trends were close to those of SCP. The formation of the carboxylic acids involved a sharp toxicity decrease, thus ensuring overall detoxification. [ABSTRACT FROM AUTHOR]

Abstract: A reliable and specific method was developed for the determination of the cytotoxic drugs cyclophosphamide and ifosfamide in sewage effluent. The most successful combination was found to be Strata-X solid-phase extraction followed by Florisil® clean-up with analysis by liquid chromatography–tandem mass spectrometry. Quantification by internal standardisation was achieved using custom synthesised d4-cyclophophosphamide. The mass spectrometer was operated in highly selective reaction monitoring (HSRM) mode, which significantly reduced matrix noise and improved sensitivity. Although it suffered from some ionisation suppression, electrospray ionisation (ESI) was found to give an order of magnitude better sensitivity in terms of limit of detection than atmospheric pressure chemical ionisation (APCI). Using final effluent from two different sewage treatment plants, the method was validated following official European guidelines and shown to be a high performance tool for routine analysis at the sub-nanogram per litre level. Depending on the matrix, the limit of detection for cyclophosphamide was between 0.03ng/L and 0.12ng/L and for ifosfamide between 0.05ng/L and 0.09ng/L. For cyclophosphamide the accuracy and precision, tested at 1.7ng/L, were 98–109% and ≤13%, CV respectively. For ifosfamide the accuracy and precision, tested at 1.1ng/L, were 98–113% and ≤15% CV, respectively. Depending on the sample matrix the absolute recovery of the internal standard was between 57% and 70%. The method was tested by analysis of spot samples taken from the final effluent discharges of two sewage treatment plants; the first using a conventional trickling filter treatment process and second employing activated sludge followed by ultra violet treatment. Cyclophosphamide was detected at 0.19ng/L at the first plant and at the second detected at 3.7ng/L and 3.5ng/L, before and after the UV treatment process; ifosfamide was not detectable at either plant. [Copyright &y& Elsevier]

Abstract: Effect of filter bed temperature on sewage treatment efficiency by vermifiltration was studied by analyzing influent and effluent quality of vermifiltration at hydraulic loading of 4.8m3/m2 d in a pilot scale. The results showed that the influence of the filter bed temperature on the removal of organics was in accordance with the binomial distribution and that on removal of NH4+-N was in accordance with the Sigmoidal equation. No obvious influence was detected on the removal of TN and TP. The experimental results also indicated that the optimal filter bed temperature of the quartz sand vermifiltration and the ceramisite grain vermifiltration were in the range of 15∼24°C and 18∼25°C, respectively. The ceramisite grain has a buffer capacity with the variations of the filter bed temperature, which has better resistance to the adverse impact of vermifiltration under lower and higher temperature conditions than that of the quartz sand. Additionally, the analysis of the insignificant influence of the different filter bed temperature on the removal of TN and TP was carried out. [Copyright &y& Elsevier]

Interactions of ozone with organic precursors during water treatment may generate carcinogenic N-nitrosodimethylamine (NDMA) byproduct. This study investigates the reaction mechanisms responsible for NDMA formation from ozonation of the commonly used poly(diallyldimethylammonium chloride) (polyDADMAC) coagulant. Upon ozonation, polyDADMAC yields the highest amount of NDMA among several water treatment polymers, including polyamines and cationic polyacrylamides. Ozonation transforms polyDADMAC to dimethylamine (DMA) and NDMA formation is correlated to polyDADMAC degradation and DMA release. Hydroxyl radicals generated from ozone play an important role in the degradation of polyDADMAC's quaternary ammonium ring groups and subsequent release of secondary amine. Although nitrite and formaldehyde are detected as ozonation products of DMA and polyDADMAC, contribution of formaldehyde-enhanced nitrosation pathway is determined to be insignificant in NDMA formation. In contrast, reaction of hydroxylamine, another ozonation product of DMA, with DMA in the presence of ozone is deemed critical in the formation of NDMA during ozonation. The study results show that that contact of polyDADMAC with ozone will lead to release of the more potent NDMA precursor DMA but may not generate a significant amount of NDMA under typical drinking water treatment conditions due to low yield. The mechanistic understanding from this study can help develop source control strategies for minimization of NDMA formation risk at water and wastewater utilities. [ABSTRACT FROM AUTHOR]

Abstract: Sustainable waste management system for effluents treatment sludge has been a pressing issue for pulp and paper sector. Recycling is always recommended in terms of environmental sustainability. Following an approach of waste valorisation, this work aims to demonstrate the technical viability of producing fiber-cement roof sheets incorporating cellulose primary sludge generated on paper and pulp mills. From the results obtained with preliminary studies it was possible to verify the possibility of producing fiber-cement sheets by replacing 25% of the conventional used virgin long fiber by primary effluent treatment cellulose sludge. This amount of incorporation was tested on an industrial scale. Environmental parameters related to water and waste, as well as tests for checking the quality of the final product was performed. These control parameters involved total solids in suspension, dissolved salts, chlorides, sulphates, COD, metals content. In the product, parameters like moisture, density and strength were controlled. The results showed that it is possible to replace the virgin long fibers pulp by primary sludge without impacts in final product characteristics and on the environment. This work ensures the elimination of significant waste amounts, which are nowadays sent to landfill, as well as reduces costs associated with the standard raw materials use in the fiber-cement industrial sector. [ABSTRACT FROM AUTHOR]

This study investigated adsorption of chromium on to a bio-adsorbent, Moringa oleifera seed. Different by-products of the seed processing were used as adsorbents. These include: the Whole Seed Powder (WSP), the Residue after Coagulant Extraction (RaCE) and an Activated Carbon (AC) prepared from the seed husk. Adsorption studies for the removal of Cr(III) and Cr(VI) were carried out in batch experiments and the effects of adsorbent dosage, contact time, pH and initial chromium concentration were analysed. Experimental results showed that maximum removal of Cr(III) and Cr(VI) was observed at pH 7 and pH 2, respectively. The percentage removals of Cr(III) by WSP, RaCE and AC were: 97, 94 and 99.9%, respectively. And the percentage removals of Cr(VI) by RaCE and AC were 47 and 83.2%, respectively. RaCE showed similar adsorption capacity to the WSP, which indicates that it is possible to extract a coagulant and use the waste product for adsorption. By using the RaCE, residual dissolved organic carbon in the treated water was significantly reduced compared to using the WSP. These results indicate that biomaterials can be considered as potential adsorbents for heavy metals removal from water or wastewater systems. [ABSTRACT FROM AUTHOR]

Abstract: An attempt is made to address a few ecological and environment issues by developing different structural models for effluent treatment system for electroplating. The effluent treatment system is defined with the help of different subsystems contributing to waste minimization. Hierarchical tree and block diagram showing all possible interactions among subsystems are proposed. These non-mathematical diagrams are converted into mathematical models for design improvement, analysis, comparison, storage retrieval and commercially off-the-shelf purchases of different subsystems. This is achieved by developing graph theoretic model, matrix models and variable permanent function model. Analysis is carried out by permanent function, hierarchical tree and block diagram methods. Storage and retrieval is done using matrix models. The methodology is illustrated with the help of an example. Benefits to the electroplaters/end user are identified. [Copyright &y& Elsevier]

Abstract: In this research, a waste water treatment plant is systematically optimized. The waste water treatment plant is used to remove aluminium from waste water using precipitation, flocculation and flotation. In total 40 variables influence the combined unit. After systematic selection, the number of variables was reduced to six: the waste water flow, pH, agitation velocity, amount of poly-electrolyte, amount of dissolved air and aluminium concentration. For these variables an experimental design was set up and executed and the results were analyzed by means of ANOVA. With the results of the ANOVA, an empirical model was constructed. The model was used for maximization of the aluminium removal. Subsequently, validation experiments were performed to confirm the findings. The study showed that the amount of poly-electrolyte is a key factor for combined unit operation. [Copyright &y& Elsevier]

Abstract: Over the past 10–20years the amount of the natural organic matter (NOM) has been increased in raw water supplies on several areas. The presence of NOM causes many problems in drinking water treatment processes, including: (i) negative effect on water quality by colour, taste and odor problems, (ii) increased coagulant and disinfectant dose requirements (which in turn results increased sludge and potential harmful disinfection by-product formation), (iii) promoted biological growth in distribution system, and (iv) increased levels of complexed heavy metals and adsorbed organic pollutants. Thus, more efficient methods for the removal of NOM have emerged. Among these are advanced oxidation processes (AOPs). These include O3/H2O2, O3/UV, UV/H2O2, TiO2/UV, H2O2/catalyst, Fenton and photo-Fenton prosesses as well as ultrasound. In the present work, an overview of the recent research studies dealing with AOP methods for the removal of NOM and related compounds from drinking water is presented. [Copyright &y& Elsevier]

Edible rape oil can be used as raw material to produce biodiesel. In this case, wastewater can be used for irrigation. In recent years wastewater use has gained importance in water-scarce regions. In this work yield and potential to produce biodiesel of a winter rape cultivar under two irrigation treatments (urban waste water (UWW) and ground water (GW)) were compared. The trial was conducted in the Urban Waste Water Treatment Plant of Obras Sanitarias Mendoza in Tunuyán (33° 32′ 89″ S; 69° 00′ 80″ W; 859 m osl). Seed yield was higher in UWW than in GW treatment (7690 and 3886 kg/ha respectively). Biodiesel potential production was 2800 kg/ha in UWW and 1400 kg/ha in GW treatment. Biodiesel production from urban waste water irrigation rape oil is an interesting niche to produce biofuels. [ABSTRACT FROM AUTHOR]

Abstract: Similarly to other catalytic advanced oxidation processes electro-oxidation by means of boron-doped diamond (BDD) anodes generates a very efficient oxidant media containing, among others, hydroxyl radicals. In this work BDD electro-oxidation is demonstrated to be an efficient alternative to treat a wide variety of saline industrial effluents, which main properties were as follows: TOC=266–4479mg/L; [N-NH3]=61–1150mg/L; [Cl−]=1996–37,645mg/L; conductivity=5.6–64mS/cm. Experiments were conducted at laboratory and pilot scale. Treatment efficiency was evaluated in terms of TOC and N-NH3 removal, and of formation of undesired by-products such as nitrate ions and trihalomethanes. The results showed that the high concentration of chloride ions in the wastewaters resulted in chloride oxidation taking place primarily, favouring ammonia oxidation in detriment of TOC elimination. Consequently, complete elimination of ammonia could be achieved for all the wastewaters studied while TOC removals reached values as high as 90%. Additionally, biodegradability of the effluent prior to and after treatment was also evaluated by means of the respirometry technique and the energy consumption of the process was estimated. The analysis of the energy consumption recommends the application of process integration approaches for the treatment of heavily polluted industrial effluents. [Copyright &y& Elsevier]

Copyright of Estudos Tecnológicos em Engenharia is the property of Universidade do Vale do Rio dos Sinos and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article investigates the alternative amendment for soluble phosphorus (P) removal from poultry litter (PL). Study shows that the removal of PL-soluble P through water treatment residual (WTR) was biphasic. It observes minimal water-extractable P (WEP) concentration reduction for all WTR rates due to P diffusion limitations. This suggests that WTR can be a cost-effective treatment for the reduction of P availability in PL.

Abstract: The wastewaters generated from wood pulping and paper production processes are traditionally treated by biological and physicochemical processes. In order to reduce chemical oxygen demand (COD) and color to meet increasingly strict discharge standards, advanced oxidation processes (AOPs) are being adapted as polishing treatment units. Various ozone-based processes were used in this study to treat simulated wastewaters prepared from black liquor from a hardwood Kraft pulp mill in Taiwan. The experimental results showed that the COD and color were primarily removed by direct ozone oxidation and activated carbon adsorption. While the addition of activated carbon could enhance the COD and color removal during ozonation, the addition of hydrogen peroxide improved the color removal only. For the various ozone-based treatment processes, kinetic models were developed to satisfactorily predict the COD and color removal rates. According to the kinetic parameters obtained from the various ozone-based processes, the enhanced COD and color removal of ozonation in the presence of activated carbon was attributed to the regeneration of the activated carbon by ozonation. These kinetic models can be used for reactor design and process design to treat pulping wastewater using ozone-based processes. [Copyright &y& Elsevier]

Sludge drying reed beds have been used for dewatering and mineralization of sludge since the beginning of the 90s, but their insufficient performances in terms of Dry Matter [DM] content and mineralization of the sludge have made necessary new studies. Therefore, 8 pilots of 2m2 each and a full-scale plant (13,000 p.e, 8 beds of 470m2 in operation for 4 years) have been monitored to examine the influence of the sludge loading rate, the sludge quality and the loading frequency on the dewatering and mineralization efficiencies. Two filtration layers and two loading rhythms were tested on pilots which were fed at a loading rate of 25-30 kg DMm-2 yr-1 during the first year of operation (commissioning period). Hydraulic behaviour (infiltration rate, outflow), O2 and CO2 relative concentrations in the filtration media, redox potential, pollutants removal and dry matter content were assessed during all the study. The rheological quality of the extracted sludge from full scale beds was assessed and showed that its mechanical behaviour exceed those of sludge of comparable dry matter content, making its spreading easier. Therefore, this sludge could easily claim the status of solid and stabilized sludge according to the French regulation. Design and management recommendations (number of beds, loading rates, feeding/rest period) gained from the experiments results are suggested. [ABSTRACT FROM AUTHOR]

The purpose of this work was to characterize an alkaline protease from the filamentous fungus Myrothecium verrucaria and to explore its capability to degrade native poultry feathers. The enzyme was purified to homogeneity using a single chromatographic step. Recovery was high, 62%, with a specific activity of 12,851.8 U/mg protein. The enzyme is a small monomeric protein with a molecular mass of 22 ± 1.5 kDa. It presented pH optimum of 8.3 and was stable over a broad pH range (5.0-12.0). The temperature optimum was 37°C, with thermal stability at temperatures up to 45°C. The enzyme presented an efficiency of 80.3% in the degradation of poultry feather meal, releasing amino acids and soluble peptides. It was able to hydrolyze β-keratin without necessity of chemical or enzymatic reduction of the disulphide bonds. Considering that, everyday, poultry-processing plants produce feathers as a waste products, this protease can be useful in biotechnological processes aiming to improve the transformation of poultry feathers through solubilization of β-keratin into usable peptides. Furthermore, it can also be useful in processes aiming to reduce the environmental pollution caused by the accumulation of feathers. [ABSTRACT FROM AUTHOR]

This study provides a preliminary contribution to the development of an industrial process for the UV/TiO2 water treatment by introducing a novel support for TiO2 immobilization. For the following study, Methylene Blue (MB) was chosen as the model dye to evaluate this novel immobilization system. The results showed that TiO2 immobilized in a Ca-alginate bead retained its photoactivity during all of the experiments and the TiO2-gel beads presented good stability in water for maintaining its shape after several uses. When a proportion of 10% (v/v) of these beads was used, the configuration system demonstrated an improved mass transfer and consequently enhanced degradation efficiency. Experiments were also performed using 'recycled' beads. The results showed an increase in the degradation efficiency when the beads were reused, with an eventual 'self-destructive' effect. These studies showed great promise regarding the recyclable reagents with a reduction in waste at no greater cost or reduction in efficiency. Therefore, the potential of TiO2-gel beads as a simple and environmentally friendly catalyst for continuous use was developed. [ABSTRACT FROM AUTHOR]

In our experimental work the pilot plant and full scale anaerobic bioreactors of a communal sewage treatment plant were tested by applying usual control parameters (pH, volatile acid content, alkalinity, gas composition), and enzyme activity (dehydrogenase, protease, lipase) measurements. Influence of temperature change was examined in pilot plant scale, while the effect of alteration in specific organic matter load both in pilot and full scale. Among the control parameters only the change of the volatile acid concentration reflected the occurred influences. During the temperature varying experimental phase the dehydrogenase enzyme activity excellently indicated the influence of the different conditions. The effect of altering substrate load onto the gas production was also well followed by the enzyme activity data (mainly protease, lipase), and more rapidly than by measuring volatile acid concentration. In practice it is expedient to use enzyme activity measurements in those cases, when changes in the substrate composition and load are frequent. Another advantage of these tests is that they can be carried out quickly and at a relative low cost. [ABSTRACT FROM AUTHOR]

A model-based evaluation of operation conditions and control strategies was conducted for phosphorus removal in a full-scale Advanced Phase Isolation Ditch (APID) process. The APID process is an alternating type and does not have a separated anaerobic reactor. We suggested that it would be a suitable operational option for robust phosphorus removal by having a different input point for the influent and return sludge flow at specific modes. For evaluation of control strategies, three cases of influent disturbance were assumed, and five manipulated variables were selected for controlling the cases of disturbance. In the case of an increased influent flow rate, a combination of four manipulated variables is proposed through our simulation results as the best control strategy. The optimal kLa value was found to be 250/d when pollutants loading kept increasing without variations in the flow rate. When both the pollutants loading and the influent flow rates were increased simultaneously, the robust control strategy is to combine the return sludge inflow point, the exclusive operation modes which have a relatively long hydraulic retention time (HRT), operation period of 30 minutes, and the increase of the return sludge flow rate in proportion to the influent flow rate added to 300/d of kLa value. [ABSTRACT FROM AUTHOR]

Hydrologists are often faced with the problem of missing values in a precipitation-runoff process database to construct runoff prediction models. They tend to use simple and naive methods to deal with the problem of missing data. Thus far, the common practice has been to discard observations with missing values. In this paper, we present some statistically principled methods for gap filling and discuss the pros and cons of these methods. We employ and discuss imputations of missing values by means of self-organizing map (SOM), multilayer perceptron (MLP), multivariate nearest-neighbor (MNN), regularized expectation-maximization algorithm (REGEM) and multiple imputation (Ml) in the context of a precipitation-runoff process database in northern Iran in order to construct a serially complete database for analyses such as runoff prediction. In our case, the SOM and MNN tend to give similar and robust results. REGEM and Ml build on the assumption of multivariate normal data, which we don't seem to have in one of our cases. MLP tends to produce inferior results because it fragments the data into 68 different models. Therefore, we conclude that it makes most sense to use either the computationally simple MNN method or the more demanding SOM. [ABSTRACT FROM AUTHOR]

Predicting the behavior of natural organic matter (NOM), alkalinity, and pH during drinking water coagulation is difficult because of the heterogeneous chemical nature of NOM and the complexity of carbonate chemistry. Parametric and nonparametric statistical regression methods were implemented to model the removal of NOM, as measured by total organic carbon (TOC), from raw water by conventional surface water treatment and to track the behavior of pH and alkalinity. The United States Environmental Protection Agency (U.S. EPA) Information Collection Rule (ICR) database was sampled for raw water and postsedimentation data from conventional surface water plants. All models were evaluated in terms of their fit and predictive capability, and for all variables explored, the nonparametric local polynomial models outperformed their parametric linear least-squares counterparts. This was most pronounced with the pH model, and was attributed to the nonlinear relationship found between pH and one of the predictors. Between the sedimentation basin and the plant effluent, alkalinity was found to remain relatively constant, TOC decreased by 12% by filtration, and pH increased, consistent with chemical additions required to minimize corrosion in the distribution system. Modeling efforts in this article are meant to be complementary to previous chemical and process models of water treatment. [ABSTRACT FROM AUTHOR]

The number of the cities with canalized water and sewage treatment stations has increased lately and consequently having in mind the great concern on environment preservation and the quality of the water used by society. However, these stations are nowadays causing another kind of problem: a huge quantity of sludge as residue. Due to the implication of the residue on the environment and, consequently, to human life quality, performing of an accurate investigation about the components of such sludge, as well as the thermal stability of this residue in the environment become necessary. This paper presents a study on sludge from water and sewage treatment station, as well as the thermal characterization of residue. Such study was performed through FTIR, atomic absorption, thermoanalytical (TG/DTG, DTA) techniques, that made it possible to observe that the main components of the sludge are clay, carbonates and organic substance, presenting a low rate of metals and a unique thermal behavior since the sludge from the treatment station has a higher thermal stability. [ABSTRACT FROM AUTHOR]

Palm kernel coat (PKC), a waste product of oil palm production, was studied as a biosorbent for Congo Red (CR) (an anionic dye) attenuation in an aqueous stream. A batch sorption system was used, and the system variables studied included initial CR concentration and PKC dosage. A batch sorption model, based on the assumption of pseudo-first-order and pseudo-second-order mechanisms, was applied to understand the sorption dynamics of CR onto PKC and to predict the rate constant of sorption, the equilibrium sorption capacity, and the initial sorption rate when the two process variables were optimized. The linear coefficient of determination (r2) and the nonlinear chi-square test (χ2) were used to assess the fitting of the sorption dynamics to either model. An equation was developed using the pseudo-second-order model, which predicts the amount of CR at any contact time and initial concentration within the given range. The rate-limiting step of the sorption reaction was also determined using the intraparticle diffusion, liquid film diffusion, and Boyd kinetic models. The results obtained showed that intraparticle diffusion becomes rate controlling at low concentration while at high concentration film diffusion is the main rate-controlling parameter. The results of the batch desorption studies showed that chemisorption played a prominent role in the sorption process. The elution curve obtained from the continuous desorption studies showed that the elution rate was fast and high elution efficiency could be obtained with 0.1 M CH3COOH as an eluting solvent. [ABSTRACT FROM AUTHOR]

Abstract: Background: Hexachlorobenzene (HCB) is a ubiquitous environmental contaminant that, even at low doses, causes destruction of ovarian primordial germ cells in experimental studies. However, its potential for reproductive toxicity in humans exposed to background levels has not been fully evaluated. Here we examined the association between maternal levels of HCB and their infants’ birth weight. Methods: HCB was measured in milk samples from a subset of women in the Norwegian Human Milk Study (HUMIS), 2003–2006; 300 subjects were randomly chosen from the cohort and 26 from all small for gestational age (SGA) children. Additional information was obtained through questionnaires and the Medical Birth Registry. Results: Overall, HCB was associated with birth weight (adjusted b=−90g per 8μg/kg milk fat, 95% CI-275 to 8) and with SGA (odds ratio 1.8, 95% CI 0.9–3.7 per 8μg/kg milk fat (difference between the 10th and the 90th percentile)). After stratification, however, the association was present only among smokers. For birth weight for past or current smokers: b=−282, CI −467 to −98; for never smokers: b=0.5, CI −149 to 150, p-value for interaction: 0.01. Similar results were observed for head circumference, crown-heel length, and SGA. Conclusions: We saw a moderate association between HCB and markers of impaired fetal growth among past and current smokers. This finding may be non-causal and due to underlying genetic variants tied to both growth and breakdown of HCB or to confounding by unmeasured toxicants that coexist in exposure sources. It may, however, also result from HCB exposure. [Copyright &y& Elsevier]

Abstract: Objectives: We investigated effects of chronic exposure (2 months) to ambient levels of particulate matter (PM) on development of protease-induced emphysema and pulmonary remodeling in mice. Methods: Balb/c mice received nasal drop of either papain or normal saline and were kept in two exposure chambers situated in an area with high traffic density. One of them received ambient air and the other had filters for PM. Results: mean concentration of PM10 was 2.68±0.38 and 33.86±2.09μg/m3, respectively, in the filtered and ambient air chambers (p<0.001). After 2 months of exposure, lungs from papain-treated mice kept in the chamber with ambient air presented greater values of mean linear intercept, an increase in density of collagen fibers in alveolar septa and in expression of 8-isoprostane (p=0.002, p<0.05 and p=0.002, respectively, compared to papain-treated mice kept in the chamber with filtered air). We did not observe significant differences between these two groups in density of macrophages and in amount of cells expressing matrix metalloproteinase-12. There were no significant differences in saline-treated mice kept in the two chambers. Conclusions: We conclude that exposure to urban levels of PM worsens protease-induced emphysema and increases pulmonary remodeling. We suggest that an increase in oxidative stress induced by PM exposure influences this response. These pulmonary effects of PM were observed only in mice with emphysema. [Copyright &y& Elsevier]

Abstract: Ground level ozone represents a significant air quality concern in Toronto, Canada, where the national 65 ppb 8-h standard is repeatedly exceeded during the summer. Here we present an analysis of nitrogen dioxide (NO2), ozone (O3), and volatile organic compound (VOC) data from federal and provincial governmental monitoring sites from 2000 to 2007. We show that summertime VOC reactivity and ambient concentrations of NO2 have decreased over this period of time by up to 40% across Toronto and the surrounding region. This has not resulted in significant summertime ozone reductions, and in some urban areas, it appears to be increasing. We discuss the competing effects of decreased ozone titration leading to an increase in O3, and decreased local ozone production, both caused by significant decreases in NO x concentrations. In addition, by using local meteorological data, we show that annual variability in summer ozone correlates strongly with maximum daily temperatures, and we explore the effect of atmospheric transport from the southwest which has a significant influence on early morning levels before local production begins. A mathematical model of instantaneous ozone production is presented which suggests that, given the observed decreases in NO x and VOC reactivity, we would not expect a significant change in local ozone production under photochemically relevant conditions. These results are discussed in the context of Toronto''s recent commitment to cutting local smog-causing pollutants by 20% by 2012. [Copyright &y& Elsevier]

Abstract: Determination of the chemical compositions of atmospheric single particles in the Yellow Sea region is critical for evaluating the environmental impact caused by air pollutants emitted from mainland China and the Korean peninsula. After ambient aerosol particles were collected by the Dekati PM10 cascade impactor on July 17–23, 2007 at Tokchok Island (approximately 50 km west of the Korean coast nearby Seoul), Korea, overall 2000 particles (on stage 2 and 3 with cut-off diameters of 2.5–10 μm and 1.0–2.5 μm, respectively) in 10 samples were determined by using low-Z particle electron probe X-ray microanalysis. X-ray spectral and secondary electron image (SEI) data showed that soil-derived and sea-salt particles which had reacted or were mixed with SO2 and NO x (or their acidic products) outnumbered the primary and “genuine” ones (59.2% vs. 19.2% in the stage 2 fraction and 41.3% vs. 9.9% in the stage 3 fraction). Moreover, particles containing nitrate in the secondary soil-derived species greatly outnumbered those containing sulfate. Organic particles, mainly consisting of marine biogenic species, were more abundant in the stage 2 fraction than in the stage 3 fraction (11.6% vs. 5.1%). Their relative abundance was greater than the sum of carbon-rich, K-containing, Fe-containing, and fly ash particles, which exhibited low frequencies in all the samples. In addition, many droplets rich in C, N, O, and S were observed. They tended to be small, exhibiting a dark round shape on SEI, and generally included 8–20 at.% C, 0–12 at.% N, 60–80 at.% O, and 4–10 at.% S (sometimes with <3 at.% Mg and Na). They were attributed to be a mixture of carbonaceous matter, H2SO4, and NH4HSO4/(NH4)2SO4, mostly from the reaction of atmospheric SO2 with NH3 under high relative humidity. The analysis of the relationship between the aerosol particle compositions and 72-h backward air-mass trajectories suggests that ambient aerosols at Tokchok Island are strongly affected not only by seawater from the Yellow Sea but also by anthropogenic pollutants emitted from China and the Seoul–Incheon metropolis, resulting in the dominance of complex secondary aerosol particles. [Copyright &y& Elsevier]

Abstract: In this work, we investigate the frequency-size distribution of three pollution indexes (PM10, NO2 and SO2) in Shanghai. They are well approximated by power-law distributions, which suggest that air pollution might be a manifestation of self-organized criticality. We introduce a new numerical sandpile model with decay coefficient to reveal inherent dynamic mechanism of air pollution. Only changing the number value of decay coefficient of pollutants, this model gives a good simulation of three pollutants'' statistical characteristic. This work shows that it is the self-organized criticality of the air pollutants that results in the temporal variation of air pollutant indexes and the minor air pollution sources can trigger the occurrence of large pollutant events by SOC behavior. [Copyright &y& Elsevier]

Volatile fatty acids (VFAs), the carbon source of biological nutrients removal, can be produced by waste activated sludge (WAS) anaerobic fermentation. However, because of high protein content and low carbon to nitrogen mass ratio (C/N) of WAS, the production of VFAs, especially propionic acid, a more preferred VFA than acetic acid for enhanced biological phosphorus removal (EBPR), is limited. After the addition of carbohydrate (rice was used as the model matter) to the WAS anaerobic fermentation system to balance the C/N ratio, the effect of pH on WAS protein conversion and VFAs production was investigated in this paper. Experimental results showed that the addition of carbohydrate matter caused a remarkable enhancement of WAS protein conversion and protease activity, and an apparent synergistic effect between WAS and carbohydrate matter was observed. The study of pH effect revealed that pH influenced not only the total VFAs production but the percentage of individual VFA. The maximal VFAs production (520.1 mg COD per gram of volatile suspended solids (VSS)) occurred at pH 8.0 and a fermentation time of 8 d, which was more than three times that at uncontrolled pH (150.2 mg COD/g VSS). The analysis of the composition of VFAs showed that propionic acid ranked first at pH 6.0-9.0 (around 50%) whereas acetic acid was the dominant product at other pHs investigated. Thus, the suitable conditions for propionic acid-enriched VFAs production were pH 8.0 and a time of 8 d. Further investigation showed that as there was more fermentation substrate consumption with lower biogas generation at pH 8.0, improved VFAs production was observed. Also, the key enzymes relevant to propionic acid formation exhibited the highest activities at pH 8.0, which resulted in the greatest propionic acid content in the fermentative VFAs. The 16S rRNA gene clone library demonstrated that Clostridia, β-Proteobacteria, and Bacteroidetes were the dominant microbial community when the current anaerobic fermentation system was operated at pH 8.0. With the fermentative VFAs as the additional carbon source of municipal wastewater, the EBPR performance was significantly increased. [ABSTRACT FROM AUTHOR]

The bottom-up construction and operation of mechanical machines of molecular size is a topic of high interest for nanoscience, and a fascinating challenge of nanotechnology. Like their macroscopic counterparts, nanoscale machines need energy to operate. Although most molecular motors of the biological world are fueled by chemical reactions, light is a very good choice to power artificial molecular machines because it can also be used to monitor the state of the machine, and makes it possible to obtain systems that show autonomous operation and do not generate waste products. By adopting an incrementally staged design strategy, photoinduced processes can be engineered within multicomponent (supramolecular) species with the purpose of obtaining light-powered molecular machines. Such an approach is illustrated in this tutorial reviewby describing some examples based on rotaxanes investigated in our laboratories. [ABSTRACT FROM AUTHOR]

Activated sludge from the municipal waste water treatment plant in Hamburg was seeded with mineral nitrite medium and incubated at 10°C, 17°C and 28°C. Dominant lithoautotrophic nitrite-oxidizing bacteria have been identified by electron microscopy, denaturing and temperature gradient gel electrophoresis and PCR with genus-specific primer pairs. The results have revealed the existence of three different genera of nitrite-oxidizing bacteria, namely Nitrospira, Nitrobacter and a novel cold-adapted nitrite oxidizer. As shown by electron microscopy members of the novel genus coexisted in activated sludge together with Nitrospira. A temperature-dependent shift in the population structure was demonstrated by cultivation-based approaches. The novel nitrite oxidizer was enriched at temperatures of 10°C and 17°C. Representatives of Nitrospira were able to grow in a broad temperature range between 10°C and 28°C and members of Nitrobacter were enriched during incubations at 17°C and 28°C. By subsequent 16S rDNA sequencing, the cold-adapted nitrite oxidizer was shown to be closely related to the betaproteobacterium ‘ Candidatus Nitrotoga arctica’. These findings demonstrated that the population structure of nitrite-oxidizing bacteria in activated sludge is more complex than previously thought and responds strongly to long-term temperature changes. [ABSTRACT FROM AUTHOR]

Abstract: The vertical distributions of five potential pollutants – Zn, As, Br, Sn, and Sb – were determined via epithermal neutron activation in the upper 50cm of unconsolidated sediments from the Black Sea, which were collected 600m below sea surface. This analysis demonstrated increasing concentrations towards the upper limits of sediments, which were greater than alert concentrations in the case of As and Br, and in accordance with Romanian Environment Regulations. The utilization of Chernobyl 137Cs as a time marker allowed for dating of this region to the last 100 years. [Copyright &y& Elsevier]

Continuous flow experiments were performed to study the effects of acidogenic biomass development, induced by feeding with non-acidified substrate, on the operation and performance of an anaerobic membrane bioreactor (AnMBR). The AnMBR was operated at cross-flow velocities up to 1.5m/s and fed with a gelatine–starch–ethanol mixture. A significant fraction of acidogenic biomass developed during reactor operation, which fully determined the sludge rheology, and influenced the particle size distribution. As a result, flux levels of only 6.5l/m2 h were achieved, at a liquid superficial velocity of 1.5m/s. Even though the soluble microbial products levels in the AMBR were as high as 14g COD/l, the observed hydraulic flux was not limited by irreversible pore fouling, but by reversible cake layer formation. Propionate oxidation was the limiting step for the applied organic loading rate. The assessed specific methanogenic activity (SMA) with propionate as substrate was, however, similar to the values found by others during thermophilic treatment of non or partially acidified substrates in granular sludge bed reactors, indicating an appropriate level of the propionate oxidation capacity. [Copyright &y& Elsevier]

Abstract: Waste glass creates serious environmental problems, mainly due to the inconsistency of waste glass streams. With increasing environmental pressure to reduce solid waste and to recycle as much as possible, the concrete industry has adopted a number of methods to achieve this goal. The properties of concretes containing waste glass as fine aggregate were investigated in this study. The strength properties and ASR expansion were analyzed in terms of waste glass content. An overall quantity of 80kg of crushed waste glass was used as a partial replacement for sand at 10%, 15%, and 20% with 900kg of concrete mixes. The results proved 80% pozzolanic strength activity given by waste glass after 28 days. The flexural strength and compressive strength of specimens with 20% waste glass content were 10.99% and 4.23%, respectively, higher than those of the control specimen at 28 days. The mortar bar tests demonstrated that the finely crushed waste glass helped reduce expansion by 66% as compared with the control mix. [Copyright &y& Elsevier]

Abstract: Open waste dump systems are still widely used in Indonesia. The Jatibarang landfill receives 650–700 tons of municipal waste per day from the city of Semarang, Central Java. Some of the leachate from the landfill flows via several natural and collection ponds to a nearby river. The objectives of the study were to identify seasonal landfill leachate characteristics in this surface water and to determine the occurrence of natural attenuation, in particular the potential for biodegradation, along the flow path. Monthly measurements of general landfill leachate parameters, organic matter-related factors and redox-related components revealed that leachate composition was influenced by seasonal precipitation. In the dry season, electrical conductivity and concentrations of BOD, COD, N-organic matter, ammonia, sulphate and calcium were significantly higher (1.1–2.3 fold) than during the wet season. Dilution was the major natural attenuation process acting on leachate. Heavy metals had the highest impact on river water quality. Between the landfill and the river, a fivefold dilution occurred during the dry season due to active springwater infiltration, while rainwater led to a twofold dilution in the wet season. Residence time of leachate in the surface leachate collection system was less than 70 days. Field measurements and laboratory experiments showed that during this period hardly any biodegradation of organic matter and ammonia occurred (less than 25%). However, the potential for biodegradation of organic matter and ammonia was clearly revealed during 700 days of incubation of leachate in the laboratory (over 65%). If the residence time of leachate discharge can be increased to allow for biodegradation processes and precipitation reactions, the polluting effects of leachate on the river can be diminished. [Copyright &y& Elsevier]