42 research outputs found
Mechanical performance of concrete with partial replacement of sand by sewage sludge ash
The production of sewage sludge from waste water treatment plants is increasing all over the world. Disposal of sewage sludge is a serious environmental problem. If we think of the areas needed for sludge ash disposal, we clearly understand the importance of reusing sewage sludge ash
in concrete. This paper presents results related to the replacement of sand by sewage sludge ash. The sludge was
characterized for chemical composition (XRF analysis), crystalline phases (XRD analysis) and pozzolanic activity. The effects of incineration on crystal phases of dry sludge were investigated. Two (W/C) ratios (0.55 and 0.45) and three sludge percentages (5%, 10% and 20%) by cement
mass were used. The mechanical performance of SSAC at different curing ages (3, 7, 28 and 90 days) was assessed by means of mechanical tests. Results show that sewage sludge ash leads to a
reduction in density and mechanical strength. Results also show that concrete with 20% of sewage sludge ash and W/C=0.45 has a 28 day compressive strength of almost 30MPa
Novel removal of Anthracene from oil-contaminated water by synthesized modified magnetic nano-particles
Novel magnetic nanoparticles (MNPs) modified with (3-mercaptopropyl)-trimethoxysilane (MPTMS), grafted with allyl glycidyl ether and coupled with beta naphthol, were prepared for removal of anthracene in aqueous solutions. The grafted MNPs were characterized by transmission electron microscopy (TEM), infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA). The modified MNPs contributed to enhancement of the adsorption capacity and were prepared by co-precipitation. The modified MNPs were characterized by TEM, FT-IR and TGA and the adsorption and kinetic behavior of anthracene on the modified MNPs was examined. It was shown that the nano-adsorbent optimized adsorption capacity is at pH 7. Three kinetics models: pseudo-first-order, pseudo-second-order, and intraparticle diffusion were used to investigate the adsorption mechanism of the anthracene onto the modified MNPs. The best fit was obtained for the pseudo-second-order model. The synthesized nano adsorbent can be considered as a new method for anthracene adsorption in contaminated water with the benefit of fast removal by applying a magnetic field
Mechanical performance of concrete with partial replacement of sand by sewage sludge ash from incineration
"Advanced Materials Forum VI , vol. 730-732"The production of sewage sludge from waste water treatment plants is increasing all over
the world. Disposal of sewage sludge ash is a serious environmental problem. If we think of the
areas needed for sludge ash disposal, we clearly understand the importance of reusing sewage
sludge ash in concrete.
This paper presents results related to the replacement of sand by sewage sludge ash. The sludge was
characterized for chemical composition (XRF analysis), crystalline phases (XRD analysis) and
pozzolanic activity. The effects of incineration on crystal phases of dry sludge were investigated.
Two (W/C) ratios (0.55 and 0.45) and three sludge percentages (5%, 10% and 20%) by cement
mass were used. The mechanical performance of SSAC at different curing ages (3, 7, 28 and 90
days) was assessed by means of mechanical tests. Results show that sewage sludge ash leads to a
reduction in density and mechanical strength. Results also show that concrete with 20% of sewage
sludge ash and W/C=0.45 has a 28 day compressive strength of almost 30MPa
Simultaneous fault detection algorithm for grid-connected photovoltaic plants
In this work, the authors present a new algorithm for detecting faults in grid-connected photovoltaic (GCPV) plant. There are few instances of statistical tools being deployed in the analysis of photovoltaic (PV) measured data. The main focus of this study is, therefore, to outline a PV fault detection algorithm that can diagnose faults on the DC side of the examined GCPV system based on the t-test statistical analysis method. For a given set of operational conditions, solar irradiance and module temperature, a number of attributes such as voltage and power ratio of the PV strings are measured using virtual instrumentation (VI) LabVIEW software. The results obtained indicate that the fault detection algorithm can detect accurately different types of faults such as, faulty PV module, faulty PV String, faulty Bypass diode and faulty maximum power point tracking unit. The proposed PV fault detection algorithm has been validated using 1.98 kWp PV plant installed at the University of Huddersfield, UK
Mechanical performance and capillary water absorption of sewage sludge ash concrete (SSAC)
Disposal of sewage sludge from waste water treatment plants is a serious environmental problem of increasing magnitude. Waste water treatment generates as much as 70 g of dry solids per capita per day. Although one of the disposal solutions for this waste is through incineration, still almost 30% of sludge solids remain as ash. This paper presents results related to reuse of sewage sludge ash in concrete. The sludge was characterised for chemical composition (X-ray flourescence analysis), crystalline phases (X-ray diffraction analysis) and pozzolanic activity. The effects of incineration on crystal phases of the dry
sludge were investigated. Two water/cement (W/C) ratios (0.55 and 0.45) and three sludge ash percentages (5%,10% and 20%) per cement mass were used as filler. The mechanical performance of sewage sludge ash concrete (SSAC) at different curing ages (3, 7, 28 and 90 days) was assessed by means of mechanical tests and capillary water absorption. Results show that sewage sludge ash leads to a reduction in density and mechanical strength and to an increase in capillary water absorption. Results also show that SSAC with 20% of sewage sludge ash and W/C=0.45 has a 28 day compressive strength of almost 30 MPa. SSAC with a sludge ash contents of 5% and 10% has the same capillary water absorption coefficient as the control concrete; as for the concrete mixtures with 20% sludge ash content, the capillary water absorption is higher but in line with C20/25 strength class concretes performance
Aplication of Solar Energy for Drying of Sludge from Pharmaceutical Industrial Waste Water and Probable Reuse
Sludge, which is produced as a by-product of all treatment processes,
has considerable potential as a fertilizer and soil conditioner. Many
authorities now discharge the sludge after treatment directly to
agricultural land in liquid form, while some others dewater and dry it
first. In either case, with proper marketing, it is generally possible
for an authority to earn revenue by this means, although it is rare for
the income to cover all the cost involved. In some industrial sludge
the total solid concentration may range between 2000-100000 ppm and it
is reported that more than 6000 waste water treatment plants use the
conventional sludge drying sand bed. An experimental investigation was
carried out to assess the efficacy of solar energy for drying of sludge
from pharmaceutical industrial waste over a sand bed covered with glass
as compared to the conventional sludge drying over a sand bed as well
as to reduce environmental pollution .The two drying beds are
constructed in 12 cm thick brick wall with cement mortar and has an
effective area of 0.5 m 2. On the 0.4 m thick layer of gravel and send
the sludge layer from pharmaceutical industry was deposited. The Solar
Sludge Drying Sand Bed (SSDSB) reduced drying time by about 25-35% as
compared to the Conventional Sludge Drying Sand Bend (CSDSB). The rate
of evaporation from the sludge surface and hence the drying was a
function of solar radiation. The condensed evaporated water was
qualitatively analyzed for probable reuse
DETERMINATION OF DESIGN CRITERIA OF AN H-IFAS REACTOR IN COMPARISON WITH AN EXTENDED AERATION ACTIVATED SLUDGE PROCESS
Advanced compact wastewater treatment processes are being looked for by
cities all over the world as effluent standards are becoming more
stringent and land available for treatment plants more scarce. In this
investigation, a new biofilm process for this purpose was studied. The
design and operational criteria of a full scale extended aeration
activated sludge system was compared with an H-IFAS reactor which has
been operated at a pilot scale. The objective was to define the
feasibility of using the H-IFAS (Hybrid Integrated Fixed Film Activated
Sludge) reactor for upgrading the existing wastewater treatment plants
with conventional processes. The results showed that besides the
considerable difference between the organic loading of the two
processes, H-IFAS reactor has a very good capability to reduce
simultaneously the concentration of nitrogen and phosphorus. Organic
degradation rate in extended aeration and H-IFAS systems were 0.3 and
6.22 kgCOD/m3.day at 23.48°C, respectively. Nitrification,
denitrification and phosphorus removal rate for the H-IFAS reactor were
343.28 g N/m3.day, 338.17 gN/m3.day, and 204.78gPO4-P/m3.day,
respectively. At the same conditions, these criteria for extended
aeration activated sludge processes were obtained as 75gN/m3.day, 28.5
gN/m3.day and 7 gPO4-P/m3.day), respectively
Recycling and Reuse of Household Plastics
The study was undertaken with the objectives to: (1) Study the present
status of plastic waste management and the existing Phnom Penh
household willingness and their influence factors to segregate plastics
for recycling and reuse (plastics & non plastics); (2) Study how
other cities encouraged and obtained the participation of their
population in plastics recycling and reuse and (3) recommend which
policythegovernment should implement plastic wasterecycling in Phnom
Penh. The study was conducted in two phases. Phase one involved
secondary research such as reviewing of relevant literatures, journals,
publications, books, and reports. The second phase involved collection
of primary data via structured questionnaires. The study is analyzed
based on 429 qualified questionnaires thatwerecollected from households
in PhnomPenh byusing:percentage, mean and standard deviation. It
investigated household’s behavior toward their waste and their
willingness to separate plastics and non-plastics wastes. The
researcher considers the question of waste from households as it is
most likely the root of waste behaviors. By looking at the current
state of process and recycling plastics waste –an important
element of waste equation, the researcher hopes to shed the lights on
plastic waste issues
Kinetic analysis of enhanced biological phosphorus removal in a hybrid integrated fixed film activated sludge process
Hybrid integrated fixed film activated sludge is a promising process
for the enhancement of nitrification, denitrification and phosphorus
removal in conventional activated sludge systems that can be used for
upgrading biological nutrient removal, particularly when they have
space limitations or need modifications that will require large
monetary expenses. In this research, successful implementation of
hybrid integrated fixed film activated sludge process at temperate zone
wastewater treatment facilities has been studied by the placement of
fixed film media into aerobic, anaerobic and anoxic zones. The primary
objective of this study was to investigate the incorporation of
enhanced biological phosphorus removal into hybrid integrated fixed
film activated sludge systems and study the interactions between the
fixed biomass and the mixed liquor suspended solids with respect to
substrate competition and nutrient removal efficiencies. A pilot-scale
anaerobic-anoxic-oxic configuration system was used. The system was
operated at different mean cell residence times and influent chemical
oxygen demand/total phosphorus ratios and with split influent flows.
The experimental results confirmed that enhanced biological phosphorus
removal could be incorporated successfully into hybrid integrated fixed
film activated sludge system, but the redistribution of biomass
resulting from the integration of fixed film media and the competition
of organic substrate between enhanced biological phosphorus removal and
denitrification would affect performances. Also, kinetic analysis of
the reactor with regarding to phosphorus removal has been studied with
different kinetic models and consequently the modified Stover-Kincannon
kinetic model has been chosen for modeling studies and experimental
data analysis of the hybrid integrated fixed film activated sludge
reactor