Treating wastewater from a pharmaceutical formulation facility by biological process and ozone

Wastewater from a pharmaceutical formulation facility (TevaKS, Israel) was treated with a biological activated-sludge system followed by ozonation. The goal was to reduce the concentrations of the drugs carbamazepine (CBZ) and venlafaxine (VLX) before discharging the wastewater to the municipal wastewater treatment plant (WWTP). Both drugs were detected at extremely high concentrations in TevaKS raw wastewater ([VLX] = 11.72 ± 2.2 mg/L, [CBZ] = 0.84 ± 0.19 mg/L), and resisted the biological treatment. Ozone efficiently degraded CBZ: at an O₃ dose-to-dissolved organic carbon ratio of 0.55 (O₃/DOC), the concentration of CBZ was reduced by >99%. A lower removal rate was observed for VLX, which was decreased by ～98% at the higher O₃/DOC ratio of 0.87. Decreasing the pH of the biologically treated effluent from 7 to 5 significantly increased the ozone degradation rate of CBZ, while decreasing the degradation rate of VLX. Ozone treatment did not alter the concentration of the effluent's DOC and filtered chemical oxygen demand (COD_f). However, a significant increase was recorded (following ozonation) in the effluent's biological oxygen demand (BOD₅) and the BOD₅/COD_f ratio. This implies an increase in the effluent's biodegradability, which is highly desirable if ozonation is followed by a domestic biological treatment. Different organic byproducts were formed following ozone reaction with the target pharmaceuticals and with the effluent organic matter; however, these byproducts are expected to be removed during biological treatment in the municipal WWTP.     

Deficit irrigation of a landscape halophyte for reuse of saline waste water in a desert city

Saline waste waters from industrial and water treatment processes are an under-utilized resource in desert urban environments. Management practices to safely use these water sources are still in development. We used a deeprooted native halophyte, Atriplex lentiformis (quailbush), to absorb mildly saline effluent (1800 mg l^?1 total dissolved solids, mainly sodium sulfate) from a water treatment plant in the desert community of Twentynine Palms, California. We developed a deficit irrigation strategy to avoid discharging water past the root zone to the aquifer. The plants were irrigated at about one-third the rate of reference evapotranspiration (ET_o) calculated from meteorological data over five years and soil moisture levels were monitored to a soil depth of 4.7 m at monthly intervals with a neutron hydroprobe. The deficit irrigation schedule maintained the soil below field capacity throughout the study. Water was presented on a more or less constant schedule, so that the application rates were less than ET_o in summer and equal to or slightly greater than ET_o in winter, but the plants were able to consume water stored in the profile in winter to support summer ET. Sodium salts gradually increased in the soil profile over the study but sulfate levels remained low, due to formation of gypsum in the calcic soil. The high salt tolerance, deep roots, and drought tolerance of desert halophytes such as A. lentiformis lend these plants to use as deficit-irrigated landscape plants for disposal of effluents in urban setting when protection of the aquifer is important.     

Lime based steam autoclaved fly ash bricks

About 10 million tonnes of fly ash are produced yearly as waste from coal fired thermal power plants in Turkey. Only a small portion of this waste is utilized as a raw material in the production of cement and concrete. In this study, Seyitömer power plant fly ash was investigated in the production of light weight bricks. Fly ash, sand and hydrated lime mixtures were steam autoclaved under different test conditions to produce brick samples. An optimum raw material composition was found to be a mixture of 68% fly ash, 20% sand and 12% hydrated lime. The optimum brick forming pressure was 20 MPa. The optimum autoclaving time and autoclaving pressure were found 6 h and 1.5 MPa, respectively. The compressive strength, unit volume weight, water absorption and thermal conductivity of the fly ash–sand–lime bricks obtained under optimum test conditions are 10.25 MPa, 1.14 g/cm³, 40.5% and 0.34 W  m⁻¹ K⁻¹ respectively. The results of this study suggested that it was possible to produce good quality light weight bricks from the fly ash of Seyitömer power plant.     

Development of electrochromic evacuated advanced glazing

Electrochromic evacuated advanced glazing has been developed, combining optimum dynamic control of the solar radiation penetrating into buildings with a high degree of thermal insulation. This was achieved by the optimisation of the electrochromic device materials (electrochromic, ion storage, protective layers, transparent conductors and polymer electrolytes) and by the refinement of a sealing method for evacuated glazing. Electrochromic evacuated glazing prototypes with dimensions up to 40 cm × 40 cm have been fabricated using vacuum techniques and chemical methods. The prototypes exhibit excellent optical and thermal performance, with a contrast ratio up to 1:32 (visible dynamic transmittance range T_lum,bleached = 63% and T_lum,colored = 2%), coloration efficiency up to 92 cm²/C and mid-pane U-values as low as 0.86 W m⁻² K⁻¹. Their durability in relation to real working environmental conditions has been assessed through indoor and outdoor testing. Such a glazing can be used in building applications to improve occupant thermal comfort, contribute to a reduction in space heating and cooling loads and allow for increased areas of fenestration thereby reducing artificial lighting loads. These factors reduce the energy demand for the building and therefore contribute to the reduction of carbon dioxide emissions.     

Modelling sheltering effects of trees on reducing space heating in office buildings in a windy city

Using statistical weather analysis, computational fluid dynamics and thermal dynamic simulation, a systematic method was developed to assess quantitatively the effects of a shelterbelt on space heating, particularly with regard to the energy consumption and CO₂ emission. It was then applied to estimate the heating loads of two typical office buildings in a windy city located at 57.2North, with and without a shelterbelt. Firstly, the statistical analysis of weather data was carried out to identify the prevailing wind direction during a typical winter heating season in the location. It was to ensure the windbreak planted rightly to maximise its sheltering benefits for the buildings in its leeward. This analysis, which revealed the main weather features in the location, would help to better comprehend the results of the thermal modelling and gain insight of how the load responses to the climate. In the second part, CFD modelling predicted wind reduction due to the shelterbelt under various wind directions. The predicted data were then used to prepare two sets of weather data, the original weather file and the revised one, in which the wind data had taken into account the reduction effect of the windbreak. The third part was a dynamic thermal modelling study where two types of office buildings were selected as the representative offices in Edinburgh for the assessment of sheltering effect on energy saving and CO₂ reduction. The predicted savings over a heating season due to the shelterbelt were in a range of 16–42% and the actual values in space heating were about 2.2 kWh m⁻² for new office buildings and 14.5 kWh m⁻² for offices converted from conventional houses without insulation improvement. These significant savings were due to the local weather that is typically known as long windy winter with many cloudy days.     

Isolation of an endosulfan-degrading bacterium from a coffee farm soil: Persistence and inhibitory effect on its biological functions

Endosulfan is a lypophilic persistent organic pollutant (POP) that has caused widespread concern due to its persistence in the environment, toxicity and bioaccumulation in living organisms. The aim of this study is to isolate endosulfan-degrading bacteria taken from five coffee farms historically exposed to this insecticide which could be used in future remediation strategies. The biodegradation capability of the isolated strain as well as endosulfan's impact on some of the strain's biological functions was studied. Endosulfan and its metabolites were analyzed using TLC and GC-MS. The isolated strain, capable of growing in a liquid culture treated with this insecticide as the sole sulfur source rather than a carbon source, was selected for further study. The isolated bacterium is Gram-negative, having the morphological and biochemical characteristics of Azotobacter sp. The remaining concentrations after 6 days, using 2 and 10 mg l^? 1 of endosulfan, were 57.6 and 72.3% respectively, and the degradation constants were 0.12 d^? 1 and 0.26 d^? 1. Four metabolites were detected, one of which was identified as endosulfan ether. Endosulfan reduced nitrogenase activity but had no impact on indole 3-acetic acid production. Thus, these results suggest that this strain has the potential to act as a biocatalyst in endosulfan degradation.     

Evaluation of indoor environmental quality conditions in elementary schools׳ classrooms in the United Arab Emirates

This study presents findings of indoor environmental quality (IEQ) investigations conducted in elementary schools׳ classrooms in the United Arab Emirates (UAE). Average TVOC, CO₂, O₃, CO, and particle concentrations measured in the classrooms were 815 µg/m³, 1605 ppm, 0.05 ppm, 1.16 ppm, and 1730 µg/m³, respectively. Whereas, local authority known as Dubai Municipality recommended 300 µg/m³, 800 ppm, 0.06 ppm, 9 ppm, and 150–300 µg/m³ for TVOC, CO₂, O₃, CO, and particle, respectively. Dubai Municipality recommended temperature and relative humidity (RH) levels of 22.5 °C to 25.5 °C and 30%–60%, respectively. Average temperature and RH levels measured in the classrooms were 24.5 °C and 40.4%, respectively. Average sound level in the classrooms was 24 dB greater than recommended sound level limit of 35 dB. Six (6) classrooms had average lux levels in the range of 400–800 lux. Two (2) classrooms had average lux levels in the range of 100–200 lux. The remaining classrooms had lux levels around the recommended 300 lux. High occupancy density was observed in majority of the studied classrooms. Observations during walkthrough investigations could be used to explain measured IEQ data. Poor IEQ conditions in the studied classrooms highlight the need for further research investigation to understand how poor classrooms׳ IEQ condition could influence students׳ health, comfort, attendance rate, and academic performance.     

Organic matter accumulation during maturation of gravel-bed constructed wetlands treating farm dairy wastewaters

The accumulation of organic matter (OM) was investigated after two and five years in a series of four gravel-bed constructed wetlands supplied with different hydraulic loading rates (21, 26, 46 and 72 mm d⁻¹) of farm dairy wastewaters. At these hydraulic loadings, mean wastewater loadings of particulate OM (determined as volatile suspended solids) to the wetlands ranged between ∼1.7 and 5.8 g m⁻² d⁻¹. Vertical and horizontal gradients of OM accumulation, measured by “loss on ignition”, were sampled by stratified coring at 18 sites in each wetland, and their impact on wastewater residence times investigated in three of the wetlands using bromide as a conservative tracer. Mean accumulations of OM in the wetlands after five years operation ranged between 6.8 and 14.9 kg m⁻², increasing with wastewater loading rate. The annual rates of accumulation during the first two years were 1.2 to 2-fold higher than those in the subsequent three years. Around 50–60% of the OM occurred within the gravel substratum, the remainder forming surface sludges, commonly exceeding 50 mm depth over much of the wetland substratum. OM accumulation in the wetlands considerably exceeded that contributed from applied wastewaters, with wetland plant derived detritus supplying substantial additional quantities of OM. The effective void space of the wetland substrata was markedly reduced in the highest loaded wetland, with mean wastewater retention time reduced to ∼50% of its theoretical value (corrected for evapotranspiration losses). In contrast, the lowest-loaded wetland exhibited retention times close to theoretical values. There was, however, no direct relationship between OM accumulation and the effective retention times of the wetlands, suggesting other factors, such as differences in OM bulk density, spatial patterns of accumulation and plant root growth, and inorganic accumulations, were also influencing their hydrology.     

Experiments of evacuation speed in smoke-filled tunnel

Among tunnel fire safety strategies, evacuation speed in smoke, which is the basic evacuation performance characteristic, is one of the most important factors when assessing safety. An evacuation experiment in a full-scale tunnel filled with smoke has been done in order to clarify the relation between extinction coefficient up to Cs = 1.0 m⁻¹, which includes Cs = 0.4 m⁻¹ as a Japanese road tunnel fire prevention standard, and evacuation speed. The maximum, minimum and mean values of normal walking speeds are almost constant regardless of the extinction coefficient. As for the emergency evacuation speeds, the maximum speed is largely influenced by extinction coefficient, decreasing rapidly from 3.55 m/s at Cs = 0.30 m⁻¹ to 2.53 m/s at Cs = 0.75 m⁻¹ while the minimum and mean speeds are almost constant with a slight decrease as Cs increases. The maximum evacuation speed trends in the present experiments and those in Frantzich and Nillson (2003, 2004) and Fridolf et al. (2013), lie on the same decreasing logarithmic curve as a function of extinction coefficient.     

Turbidity changes caused by collapse of cyanobacterial gas vesicles in water pumped from lake Kinneret into the Israeli national water carrier

The cyanobacterium Aphanizomenon ovalisporum Forti appeared in Lake Kinneret for the first time in the summer and autumn of 1994 and reappeared in 1995–1997. In 1994 it formed a large bloom (6000 filaments ml⁻¹) that caused high turbidity (up to 7 NTU), which is attributed mainly to light scattering by gas vesicles. When lake water was pumped into the high-pressure pipe (2.5 MPa) of the Israeli National Water Carrier (INWC) the turbidity of the water decreased by 65%, the Aphanizomenon filaments lost their buoyancy and some filaments fragmented. Application of 0.6 MPa pressure to cultures of the Lake Kinneret strain of A. ovalisporum in a pressure nephelometer caused collapse of all gas vesicles; the turbidity decreased by 80% and all of the filaments sedimented. The mean critical collapse pressure of the gas vesicles (p_c) was 0.58±0.02 MPa (with cells suspended in hypertonic sucrose solution), the apparent mean critical collapse pressure (p_a) was 0.27±0.02 MPa (with cells suspended in culture medium) and the mean turgor pressure (p_t) was 0.33±0.02 MPa. The value of p_a is lower than the pressures in any of the five high-pressure pipes (0.6–2.5 MPa) along the INWC. It is concluded that gas vesicle collapse caused the observed decrease in turbidity in the system. The combined physical, chemical and biological treatments given in the INWC system resulted in a 99.9% decrease in the A. ovalisporum biomass.     

Safe velocity of on-fire train running in the tunnel

The safety of a running train on fire in a tunnel is a key issue for rescue operations, and the train velocity is mainly related to its safety. In this study, the relationship between the wind velocity and heat release rate (HRR), temperature field around the train, and flame/smoke pervasion rule were investigated under the conditions of variable train velocity, fire location, and fire source location. Beijing Metro was considered as a typical example, in which the safe velocity was estimated to be ∼41.83 km h⁻¹. Assuming the occurrence of fire at the center of the train, the numerical simulations of the flow field using the sliding grid of CFD were performed for a full-scale tunnel under different HRRs. When the fire source reached to the target section, the velocities of all the monitoring points rapidly increased. The velocities increased as the train tail arrived at the target section. The velocities at the measuring points increased with the increase in height, excluding the value of the position with a distance of 0.025 m from the tunnel ceiling. The average temperature and concentration of smoke in the annular space between the train and tunnel ceiling had the minimum values when the running train on fire moved with a speed of 45 km h⁻¹. Thus, the safe velocity of a subway train on fire should be managed between 41.83 km h⁻¹ and 45 km h⁻¹.     

Improved parameterization of dust emission (PM10) fluxes by the gradient method using the Naiman tower data at the Horqin desert in China

Dust emission/deposition flux has been estimated using the gradient method with the two-level (3 and 15 m high) measured PM₁₀ concentrations and the sonic anemometer measured momentum and kinematic heat fluxes at 8 m high from a 20-m monitoring tower located at Naiman (Horqin desert) in the Asian dust source region in China for the winter of November 2007 to March 2008. The time series of measured PM₁₀ concentration at 3 m high is used to identify the dust event and the non-dust event periods. It is found that the dust emission/deposition flux (F_C) shows a significant diurnal variation with the maximum emission flux of 5.8 kg km^? 2 h^? 1 at noon and the minimum of ? 1.6 kg km^? 2 h^? 1 in the afternoon for the non-dust event cases. Whereas for the dust event cases, the dust emission flux is found to occur when the prevailing winds are westerlies to northerlies with the maximum flux of 1275 kg km^? 2 d^? 1, while the maximum dust deposition flux of 148 kg km^? 2 d^? 1 occurs with the prevailing winds of southerlies to easterlies without any diurnal variation. The optimal regression equation between F_C and the friction velocity (u_*) for the dust emission cases is found to be F_C = 9.55 u_*^3.13 with the R² value of 0.73. However, this regression equation can be improved by taking into account the convective velocity (w_*). The resulting optimal regression equation is found to be F_C = 9.3(u_* ? 0.1w_*)^3.19 for the stable stratification (w_* < 0) with the R² value of 0.77 and F_C = 10.5(u_* + 0.34w_*)^4.11 for the unstable stratification (w_* > 0) with the R² value of 0.78, suggesting the importance of the convective velocity on the dust emission flux.     

Numerical study of heat transfer by laminar and turbulent natural convection in tall cavities of façade elements

Laminar and turbulent natural convection flow in a two-dimensional tall rectangular cavity heated from the vertical side has been investigated numerically for aspect ratios of 20, 40 and 80. The finite volume method was used to solve the conservation equations of mass, momentum and energy for Rayleigh numbers from 10² to 10⁸, the flow was considered either laminar or turbulent. For turbulent flow, four different turbulence models κ−ɛ were compared along with their experimental results for a cavity with an aspect ratio of 30, it was found that the better approach was with the one reported by Ince and Launder turbulent model [N. Ince, B. Launder, On the computation of buoyancy-driven turbulent flows in rectangular enclosures, Int. J. Heat Fluid Flow 10 (1989) 110–117]. The average Nusselt numbers as a function of Rayleigh numbers for the aspect ratios range of 20–80 were calculated and compared with five convective Nusselt number correlations reported from the literature. Convective Nusselt number correlations for laminar flow in the range of 10² ≤ Ra ≤ 10⁶ and for turbulent flow in the range of 10⁴ ≤ Ra ≤ 10⁸ were presented. This study will help to have more accurate heat transfer parameters for applications such as façade elements, insulating units, double-skin façades, etc.     

Preparation and performances of a novel intelligent humidity control composite material

A novel intelligent humidity control composite material with excellent humidity control performances has been prepared, comprising a natural polymer derivative (carboxymethyl cellulose (CMC)), a porous natural mineral (sepiolite), and an acrylic acid (AA)/acrylamide (AM) copolymer. It features high moisture adsorption capacity, fast response to humidity changes, small equilibrium humidity control range and good acid gas absorbability. It is suitable for maintaining a proper micro-environment for places such as museums or galleries. The appearance and structural properties of the resultant material have been investigated by scanning electronic microscope (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The humidity control performances of the material at certain relative humidity (RH) and changed absolute humidity (AH) have been measured. The adsorption capabilities of the material for sulphur dioxide and nitrogen dioxide have also been investigated in this study. The results reveal that the material maintains a relative humidity in the 57–60.5% range at 25 °C, and reaches the equilibrium levels within 3.5 h. It is worth noting that the composite material shows an excellent humidity buffering effect at changed AH and temperatures. The equilibrium moisture adsorption amount is 78.6% of its own weight. The adsorption capacities for nitrogen dioxide and sulphur dioxide are 227 mg g^?1 and 288 mg g^?1, respectively.     

Lightweight concretes of activated metakaolin-fly ash binders,with blast furnace slag aggregates

This work investigated geopolymeric lightweight concretes based on binders composed of metakaolin with 0% and 25% fly ash, activated with 15.2% of Na₂O using sodium silicate of modulus SiO₂/Na₂O = 1.2. Concretes of densities of 1200, 900 and 600 kg/m³ were obtained by aeration by adding aluminium powder, in some formulations lightweight aggregate of blast furnace slag was added at a ratio binder:aggregate 1:1; curing was carried out at 20 and 75 °C. The compressive and flexural strength development was monitored for up to 180 days. The strength diminished with the reduction of the density and high temperature curing accelerated strength development. The use of the slag had a positive effect on strength for 1200 kg/m³ concretes; reducing the amount of binder used. The thermal conductivity diminished from 1.65 to 0.47 W/mK for densities from 1800 to 600 kg/m³. The microstructures revealed dense cementitious matrices conformed of reaction products and unreacted metakaolin and fly ash. Energy dispersive spectroscopy and X-ray diffraction showed the formation of amorphous silicoaluminate reaction products.     

Effect of loading rate and oxygen supply on nitrification in a non-porous membrane biofilm reactor

A nitrifying membrane biofilm reactor (MBfR) was operated over 170 days, to assess the effect of ammonia loading rate under O₂-excess conditions, and the effect of dissolved oxygen under O₂-limiting conditions on nitrification efficiency. The MBfR was fed pure oxygen by diffusion through a non-porous membrane. Five different loading rates, ranging from 1.92 to 5.53 g N/m² d, were tested, yielding specific nitrification rates (SNR) ranging from 1.54 to 2.60 g N/m² d. SNR increased linearly with specific loading rate, up to the load of 3.5 g N/m² d, which indicated that mass transfer was linearly related to the bulk ammonia concentration. Beyond that load, substrate diffusion limitation inhibited further increase of SNR. When operating the system under limited oxygen supply conditions, 100% oxygen utilization was achievable. Maintenance of higher oxygen supply allowed a slightly higher SNR due to the growth of nitrifiers at the outer side of the biofilm (away from the membrane surface). Nitrification batch tests confirmed that the fraction of nitrifiers in the solids detached from the surface of the biofilm (and washed out with the effluent), was twice as high during oxygen-excess conditions when compared to oxygen-limiting conditions.     

decolourisation of cotton bleaching effluent with wood rotting fungus

The decolourisation of cotton bleaching effluent by a wood rotting fungus was studied. It was found that fungus No. 7 could remove more than 70% of the colour (initial A₄₀₀=2.0–2.4) from the effluent within 4 days under agitated conditions. The fungal mycelia could be reused for a prolonged time and the decolourisation activity of mycelial pellets was quite stable during a long period of cool storage. Many factors affecting the decolourisation process were studied, including: concentration of glucose, effluent, NH₄⁺ and Mn(II); initial pH; temperature. The activity of manganese peroxidase (MnP) appeared to correlate well with the decolourisation rate. After the fungal treatment, an improvement in the treatability of the effluent by other microorganisms was observed.     

Mechanical and microstructural characterization of an alkali-activated slag/limestone fine aggregate concrete

Four limestone-based, alkali-activated slag fine aggregate concretes, two of which contained amorphous silica in the form of diatomaceous earth, were fabricated using different activating solutions (NaOH/waterglass or Na₂CO₃). Emphasis in this work was placed on using simple manufacturing methods and widely available materials, to ensure that these formulae are practical as construction materials in the developing world. Although cured only at room temperature, these fine aggregate concretes have good compressive strengths (～45 MPa) and their tensile strengths increased from ～2.6 MPa after 1 day of curing to ～4 MPa after 28 day for the NaOH-activated formulae. Samples activated with Na₂CO₃ had negligible tensile strengths after 1 day, increasing to ～2.5 MPa after 28 day. The main cementing phase was shown to be calcium–silicate–hydrates in all formulae; those activated with Na₂CO₃ also showed the presence of hydrotalcite. No evidence of geopolymeric phases was found, though incorporation of Na to form N–S–H that balance charges arising from Al substitution of Si in C–S–H is likely. Despite the short (～120 s) pot life of the strongest formula, NaCl was shown to be an effective retarding agent, which reduced the strengths of different formulae, at worst, by less than 25% after 28 day of curing.