Abstract: Nitrogen is among the main nutrients encouraging the growth of organic matter and algae which cause eutrophication in water bodies. Therefore, its removal from wastewater has become a worldwide emerging concern. In this research, an innovative Membrane Bioreactor (MBR) system named “moving bed membrane bioreactor (MBMBR)” was developed and investigated under intermittently-aerated mode for simultaneous removal of organic carbon and nitrogen.
Results indicated that the variation of the intermittently aerated duration did not have an apparent impact on COD and NH4+–N removal rate, yielding the effluent with average COD and NH4+–N removal efficiency of more than 92 and 91% respectively. However, in the intermittently aerated cycle of (continuously aeration/0s mix), (aeration 90s/mix 90s) and (aeration 90s/mix 180s); the average TN removal efficiency was 67.6%, 69.5% and 87.8% respectively. At the same time, their nitrite accumulation rate was 4.5%, 49.1% and 79.4% respectively. These results indicate that the intermittently aerated mode is an efficient way to controlling the nitrification to stop at nitrition; and also the length of anoxic duration is a key factor in improving TN removal.
Abstract: Composting is a controlled technology to enhance the
natural aerobic process of organic wastes degradation. The resulting
product is a humified material that is principally recyclable for
agricultural purpose. The composting process is one of the most
important tools for waste management, by the European Community
legislation. In recent years composting has been increasingly used as
a remediation technology to remove biodegradable contaminants
from soil, and to modulate heavy metals bioavailability in
phytoremediation strategies. An optimization in the recovery of
resources from wastes through composting could enhance soil
fertility and promote its use in the remediation biotechnologies of
contaminated soils.
Abstract: Anaerobic modeling is a useful tool to describe and
simulate the condition and behaviour of anaerobic treatment units for
better effluent quality and biogas generation. The present
investigation deals with the anaerobic treatment of brewery
wastewater with varying organic loads. The chemical oxygen demand
(COD) and total suspended solids (TSS) of the influent and effluent
of the bioreactor were determined at various retention times to
generate data for kinetic coefficients. The bio-kinetic coefficients in
the modified Stover–Kincannon kinetic and methane generation
models were determined to study the performance of anaerobic
digestion process. At steady-state, the determination of the kinetic
coefficient (K), the endogenous decay coefficient (Kd), the maximum
growth rate of microorganisms (μmax), the growth yield coefficient
(Y), ultimate methane yield (Bo), maximum utilization rate constant
Umax and the saturation constant (KB) in the model were calculated to
be 0.046 g/g COD, 0.083 (d¯¹), 0.117 (d-¹), 0.357 g/g, 0.516 (L
CH4/gCODadded), 18.51 (g/L/day) and 13.64 (g/L/day) respectively.
The outcome of this study will help in simulation of anaerobic model
to predict usable methane and good effluent quality during the
treatment of industrial wastewater. Thus, this will protect the
environment, conserve natural resources, saves time and reduce cost
incur by the industries for the discharge of untreated or partially
treated wastewater. It will also contribute to a sustainable long-term
clean development mechanism for the optimization of the methane
produced from anaerobic degradation of waste in a close system.
Abstract: Soil is a complex physical and biological system that provides support, water, nutrients and oxygen to the plants. Apart from these, it acts as a connecting link between inorganic, organic and living components of the ecosystem. In recent years, presence of xenobiotics, alterations in the natural soil environment, application of pesticides/inorganic fertilizers, percolation of contaminated surface water as well as leachates from landfills to subsurface strata and direct discharge of industrial wastes to the land have resulted in soil pollution which in turn has posed severe threats to human health especially in terms of causing carcinogenicity by direct DNA damage. The present review is an attempt to summarize literature on sources of soil pollution, characterization of pollutants and their consequences in different living systems.
Abstract: The aim of this work is to use an environmental, cheap; organic non-traditional admixture to improve the structural behavior of sustainable reinforced concrete beams contains different ratios of recycled concrete aggregate. The used admixture prepared by using wastes from vegetable oil industry. Under and over reinforced concrete beams made from natural aggregate and different ratios of recycled concrete aggregate were tested under static load until failure. Eight beams were tested to investigate the performance and mechanism effect of admixture on improving deformation characteristics, modulus of elasticity and toughness of tested beams. Test results show efficiency of organic admixture on improving flexural behavior of beams contains 20% recycled concrete aggregate more over the other ratios.
Abstract: 40L of hollow fiber membrane bioreactor with solids retention times (SRT) of 30, 15 and 4 days were setup for treating synthetic wastewater at hydraulic retention times (HRT) of 12, 8 and 4 hours. The objectives of the study were to investigate the effects of SRT and HRT on membrane fouling. A comparative analysis was carried out for physiochemical quality parameters (turbidity, suspended solids, COD, NH3-N and PO43-). Scanning electron microscopy (SEM), energy diffusive X-ray (EDX) analyzer and particle size distribution (PSD) were used to characterize the membrane fouling properties. The influence of SRT on the quality of effluent, activated sludge quality, and membrane fouling were also correlated. Lower membrane fouling and slower rise in trans-membrane pressure (TMP) were noticed at the longest SRT and HRT of 30d and 12h, respectively. Increasing SRT results in noticeable reduction of dissolved organic matters. The best removal efficiencies of COD, TSS, NH3-N and PO43- were 93%, 98%, 80% and 30% respectively. The high HRT with shorter SRT induced faster fouling rate. The main fouling resistance was cake layer. The most severe membrane fouling was observed at SRT and HRT of 4 and 12, respectively with thickness cake layer of 17mm as reflected by higher TMP, lower effluent removal and thick sludge cake layer.
Abstract: The possibility of using industrial hemp as a source of natural fibers for purpose of construction, mainly for the preparation of lightweight composites based on hemp hurds is described. In this article, an overview of measurement results of important technical parameters (compressive strength, density, thermal conductivity) of composites based on organic filler - chemically modified hemp hurds in three solutions (EDTA, NaOH and Ca(OH)2) and inorganic binder MgO-cement after 7, 28, 60, 90 and 180 days of hardening is given. The results of long-term water storage of 28 days hardened composites at room temperature were investigated. Changes in the properties of composites caused by chemical treatment of hemp material are discussed.
Abstract: The hydrolysis of lactose using β-galactosidase is one of the most promising biotechnological applications, which has wide range of potential applications in food processing industries. However, due to intracellular location of the yeast enzyme, and expensive extraction methods, the industrial applications of enzymatic hydrolysis processes are being hampered. The use of permeabilization technique can help to overcome the problems associated with enzyme extraction and purification of yeast cells and to develop the economically viable process for the utilization of whole cell biocatalysts in food industries. In the present investigation, standardization of permeabilization process of novel yeast isolate was carried out using a statistical model approach known as Response Surface Methodology (RSM) to achieve maximal b-galactosidase activity. The optimum operating conditions for permeabilization process for optimal β-galactosidase activity obtained by RSM were 1:1 ratio of toluene (25%, v/v) and ethanol (50%, v/v), 25.0 oC temperature and treatment time of 12 min, which displayed enzyme activity of 1.71 IU /mg DW.
Abstract: Muscid flies are known to be vectors of disease agents and species that annoy humans and domesticated animals. An example of these flies is Musca domestica (house fly) whose adult and immature stages occur in a variety of filthy organic substances including household garbage and animal manures. They contribute to microbial contamination of foods. It is therefore imperative to control these flies as a result of their role in Public health. The second and third instars of Musca domestica (Linn) were infected with varying cell loads of Bacillus subtilis in vitro for a period of 48 hours to evaluate its larvicidal activities. Mortality of the larvae increased with incubation period after treatment with the varying cell loads. Investigation revealed that the second instars larvae were more susceptible to treatment than the third instars treatments. Values obtained from the third instar group were significantly different (P
Abstract: Organic Rankine Cycle (ORC) has potential in reducing fossil fuels and relaxing environmental problems. In this work performance analysis of ORC is conducted based on the second law of thermodynamics for recovery of low temperature heat source from 100oC to 140oC using R134a as the working fluid. Effects of system parameters such as turbine inlet pressure or source temperature are theoretically investigated on the exergy destructions (anergies) at various components of the system as well as net work production or exergy efficiency. Results show that the net work or exergy efficiency has a peak with respect to the turbine inlet pressure when the source temperature is low, however, increases monotonically with increasing turbine inlet pressure when the source temperature is high.
Abstract: This study examined the effects of zinc (Zn) from
different sources and microbial phytase on the broiler performance,
biochemical parameters and digestibility of nutrients when they were
added to broiler diets containing low available phosphorus. A total of
875, 1-day-old male broilers of the Ross 308 strain were randomly
separated into two control groups (positive and negative) and five
treatment groups each containing 125 birds; each group was divided
into 5 replicates of 25 birds. The positive control (PC) group was fed
a diet containing adequate concentration (0.45%) of available
phosphorus due to mineral premix (except zinc) and feeds. The
negative control (NC) group was fed a basal diet including low
concentration (0.30%) of available phosphorus due to mineral premix
(except zinc) and feeds. The basal diet was supplemented with 0.30%
phosphorus and 500 FTU phytase (PH); 0.30% phosphorus and
organic zinc (OZ; 75mg/kg of Zn from Zn-proteinate); 0.30%
phosphorus and inorganic zinc (IZ; 75 mg/kg of Zn from ZnSO4);
0.30% phosphorus, organic zinc and 500 FTU phytase (OZ + PH);
and 0.30% phosphorus, inorganic zinc and 500 FTU phytase (IZ +
PH) in the treatment groups 1, 2, 3, 4 and 5, respectively. The lowest
value for mean body weight was in the negative control group on a
diet containing low available phosphorus. The use of
supplementation with organic and inorganic zinc alone or in
combination with microbial phytase significantly (P
Abstract: The objectives of the present study were to estimate the microbial-N flow to the small intestine and to predict the digestible organic matter intake (DOMI) in grazing Karayaka sheep based on urinary excretion of purine derivatives (xanthine, hypoxanthine, uric acid, and allantoin) by the use of spot urine sampling under field conditions. In the trial, 10 Karayaka sheep from 2 to 3 years of age were used. The animals were grazed in a pasture for ten months and fed with concentrate and vetch plus oat hay for the other two months (January and February) indoors. Highly significant linear and cubic relationships (P
Abstract: The volatile organic compounds - BTEX (Benzene, Toluene, Ethylbenzene, and Xylene) petroleum derivatives, have high rates of toxicity, which may carry consequences for human health, biota and environment. In this directon, this paper proposes a method of treatment of these compounds by using corona discharge plasma technology. The efficiency of the method was tested by analyzing samples of BTEX after going through a plasma reactor by gas chromatography method. The results show that the optimal residence time of the sample in the reactor was 8 minutes.
Abstract: Polyethylene glycol (PEG) is a condensation polymer of ethylene oxide and water. It is soluble in water and in many organic solvents. PEG is used to make emulsifying agents, detergents, soaps, plasticizers, ointments etc. Ethanol (C2H5OH) also known as ethyl alcohol is a well-known organic compound and has wide applications in chemical industry as it is used as a solvent for paint, varnish, in preserving biological specimens, used as a fuel mixed with petrol etc. Though their chemical and physical properties are already studied, still because of their uses in day to day life the authors thought it is better to study some more of their physical properties like ultrasonic velocity and hence adiabatic compressibility, free length, etc. A detailed study of such properties and some excess parameters like excess adiabatic compressibility, excess free volume and few more in the liquid mixtures of these two compounds with PEG as a solute and Ethanol as a solvent at various mole fractions may throw some light on deeper understanding of molecular interaction between the solute and the solvent supported by NMR, IR etc. Hence the present research work is on ultrasonics/allied studies on these two liquid mixtures. Ultrasonic velocity (U), density (ρ) and viscosity (η) at room temperature and at different mole fraction from 0 to 0.055 of ethanol in PEG have been experimentally carried out by the authors. Acoustical parameters such as adiabatic compressibility (β), free volume (Vf), acoustic impedance (Z), internal pressure (πi), intermolecular free length (Lf) and relaxation time (τ) were calculated from the experimental data. We have calculated excess parameters like excess adiabatic compressibility (βE), excess internal pressure (πiE) free length (LfE) and excess acoustic impedance (ZE) etc for these two chosen liquid mixtures. The excess compressibility is positive and maximum around a mole fraction 0.007 and excess internal pressure is negative and maximum at the same mole fraction and longer free length. The results are analyzed and it may be concluded that the molecular interactions between the solute and the solvent is not strong and it may be weak. Appropriate graphs are drawn.
Abstract: These SOAP project Pacific Ocean measurements reveal that phytoplankton blooms with sunny conditions make possible secondary organic contribution to ultrafine particles size and composition, and thus on cloud formation ability, and finally on climate. This is in agreement with other biologically active region observations about the presence of secondary organics even the exact fraction is also depending on the local marine life (e.g. plankton blooms, seaweeds, corals). An organic contribution is clearly needed to add to CLAW hypothesis.
Abstract: In order to investigate the properties of coral reef origin secondary aerosol and especially the contribution of secondary organic aerosol, ethanol affinity to atmospheric nucleation mode particles (diameter
Abstract: Due to climate warming and consequently due to ice and snow melting of the Arctic Ocean, the highly biologically active ocean surface area has been expanding quickly making possible longer marine biota growth seasons during polar summers. That increase the probability of the remote marine environment secondary contribution, especially secondary organic contribution, to the particle production and particle growth events and particle properties, consequently effecting on the open ocean, pack ice and ground based regions radiation budget and thus on the feedbacks between arctic biota, particles, clouds, and climate.
Abstract: Organic solvents find various applications in many industrial sectors and laboratories as dilution solvents, dispersion solvents, cleaners and even lubricants. Millions of tons of spent organic solvents (SOS) are generated each year worldwide, prompting the need for more efficient, cleaner and safer methods for the treatment and resource recovery of SOS. As a result, acetone, selected as a model compound for SOS, was gasified in supercritical water to assess the feasibility of resource recovery of SOS by means of supercritical water processes. Experiments were conducted with an autoclave reactor. Gaseous product is mainly consists of H2, CO, CO2 and CH4. The effects of three major operating parameters, the reaction temperature, from 673 to 773K, the dosage of oxidizing agent, from 0.3 to 0.5 stoichiometric oxygen, and the concentration of acetone in the feed, 0.1 and 0.2M, on the product gas composition, yield and heating value were evaluated with the water density fixed at about 0.188g/ml.
Abstract: Coagulation is a process that sanitizes leather effluents. It aims to reduce pollutants such as Chemical Oxygen Demand (COD), chloride, sulfate, chromium, suspended solids, and other dissolved solids. The current study aimed to evaluate coagulation efficiency of tannery wastewater by analyzing the change in organic matter, odor, color, ammonium ions, nutrients, chloride, H2S, sulfate, suspended solids, total dissolved solids, fecal pollution, and chromium hexavalent before and after treatment. Effluent samples were treated with coagulants Ca(OH)2 and FeSO4 .7H2O. The best advantages of this treatment included the removal of: COD (81.60%); ammonia ions (98.34%); nitrate ions (92%); chromium hexavalent (75.00%); phosphate (70.00%); chloride (69.20%); and H₂S (50%). Results also indicated a high level of efficiency in the reduction of fecal pollution indicators. Unfortunately, only a modest reduction of sulfate (19.00%) and TSS (13.00%) and an increase in TDS (15.60%) was observed.
Abstract: Microfibrous palygorskite and tubular halloysite clay mineral combined with nanocrystalline TiO2 are incorporating in the preparation of nanocomposite films on glass substrates via sol-gel route at 450oC. The synthesis is employing nonionic surfactant molecule as pore directing agent along with acetic acid-based sol-gel route without addition of water molecules. Drying and thermal treatment of composite films ensure elimination of organic material lead to the formation of TiO2 nanoparticles homogeneously distributed on the palygorskite or halloysite surfaces. Nanocomposite films without cracks of active anatase crystal phase on palygorskite and halloysite surfaces are characterized by microscopy techniques, UV-Vis spectroscopy, and porosimetry methods in order to examine their structural properties.
The composite palygorskite-TiO2 and halloysite-TiO2 films with variable quantities of palygorskite and halloysite were tested as photocatalysts in the photo-oxidation of Basic Blue 41 azo dye in water. These nanocomposite films proved to be most promising photocatalysts and highly effective to dye’s decoloration in spite of small amount of palygorskite-TiO2 or halloysite-TiO2 catalyst immobilized onto glass substrates mainly due to the high surface area and uniform distribution of TiO2 on clay minerals avoiding aggregation.