|Collecting information for upscaling Baffled membrane bioreactor|
Baffled membrane bioreactor can remove nitrogen only single tank. That’s
why B-MBR is expected to remove nitrogen with reducing space and energy.
Nevertheless, previous works about B-MBR is experiments with labo-scale or
pilot-scale and these results cannot use for building full-scale B-MBR. In
my research, I collect details information about nitrogen removal with
building full-scale in mind.
|Research of making urea-formaldehyde (UF) fertilizer from human urine|
In the world, the amount of nitrogen fertilizers consumption keeps growing
because of population increasing. Ammonia and urea fertilizers which are
easily dissolved in water cause low efficiency of nutrients utilization by
plants resulting from evaporation, washing out by stormwater and
groundwater penetration. Slow release fertilizers can solve this problem by
insoluble property in water. On the other hand, human urine appeared to
have an important potential for the nitrogen fertilizer owing to high
nitrogen concentration. So, I try to produce a slow release fertilizer of
methylene urea from human urine and find the efficiency of nitrogen release
|Concentration of municipal wastewater by FO process with RO brine|
High salt concentration of RO brine from disalination process causes unpreferable effect on the sea. Municipal wastewater has a potencial as an energy source in spite of its low concentration of organic matter. FO process can concentrate the wastewater with RO brine and less energy. This study investigates the feasibility of concentration of wastewater by FO process with RO brine from the view point of energy self-reliance.
|Characterization of biopolymers causing MF/UF membrane fouling in the surface water|
Hydrophilic macromolecular organics referred to as biopolymers have been shown to be major players in the membrane fouling. Biopolymers are mainly composed of polysaccharides and proteins, however, why biopolymers cause membrane fouling is not still sufficiently clarified. In this study, biopolymers were refined from some drinking water sources and then the advanced water quality measurement such as LC-OCD and QCM were carried out in order to investigate the characteristics of biopolymers causing membrane fouling.
|Design of solid fertilizer production process from dairy liquid waste|
A significant amount of livestock waste, consisting feces, urine and washing water, is discharging from cattle barns. In Japan, half of dairy farmers separate the livestock waste into solid and liquid fractions. The solid fraction is composted to make solid fertilizer, while some of solid compost is provided to farmers cultivating grains. The liquid fraction is stored in a storage tank then used as liquid fertilizer. Although the liquid fertilizer contains ammonia and sodium which might respectively cause the odor problem and salt damage. These factors make it difficult for farmers to apply liquid fertilizer for cultivating plants. On the other hand, the liquid fraction of livestock waste from cow barn is rich in nitrogen and potassium and could be considered to be resource. Therefore, production of solid fertilizers with controlled composition is required for livestock-waste management. The objective of this research is to propose a solid fertilizer production unit from the liquid fraction of the livestock waste.
|Assessment of MBR sludge filterability by capillary suction time (CST) and lipopolysaccharide (LPS)|
Filterability of sludge in membrane bioreactors (MBRs) fluctuates and
affects the operation of MBRs. Therefore, it is important to establish an
easy method to quickly and adequately assess filterability of MBR sludge
for wider application of MBR technology. Variation of sludge filterability
in a long-term operation of a pilot-scale MBR was investigated in this
|Direct membrane filtration of municipal wastewater for recovery of organic
matter with flat-sheet ceramic membranes|
Organic matter contained in municipal wastewater should be regarded as a
new energy resource. However, concentration of organic matter in domestic
wastewater is too low to directly apply an energy recovery process such as
anaerobic digestion. Hollow fiber membrane made from PVDF can efficiently
retain organic matter in municipal wastewater, but the reversible fouling
couldn't be efficiently controlled. The use of ceramic membrane allowed us
to carry out intensive physical cleaning. And we have demonstrated that
circulation of granular materials in the filtration tank could completely
control the formation of cake. The objective of this study is to operate
direct membrane filtration in long term by applying granular materials to
flat-sheet ceramic membranes.
|Mitigation of membrane fouling caused by biopolymers by application of ultrafiltration|
Although low-pressure membrane processes such as microfiltration and
ultrafiltraion are promising for drinking water treatment, problems caused
by membrane fouling are still major obstacles for widespread use of such
process. In recent studies, hydrophilic macromolecular organics referred to
as biopolymers have been shown to be the major players in membrane fouling.
It has also been shown that large biopolymers with molecular weights of
more than 1 million Da have high fouling potential. Thus, it was postulated
that application of UF can prevent membrane fouling caused by such large
biopolymers because the small pore size of a UF membrane does not allow
them to intrude into micropores. In the present study, this postulation is
investigated in a series of filtration tests in which hollow-fiber MF/UF
membranes made from the same polymer material with three different drinking
|Membrane Fouling on Urine Concentration by FO process|
Urine is rich in nutrients which can be used as a fertilizer. It must be transported from urban to rural areas, because it is mainly produced in urban area, with the high transport cost resulting from its balky volume. A forward osmosis (FO) process was applied for volume reduction of urine. Many papers report membrane fouling problems for long term operation on membrane filtration processes owing to high concentration of organic matter and precipitates, although there is no report on FO membrane fouling under long term operation. Thus, the objective of this paper is to investigate the fate of FO membrane fouling by repetition of urine concentration.
|Synthesis of coated magnetic nanoparticles for urine concentration by forward osmosis process|
In urban slums, it is difficult to introduce sewage system for physical and economic reasons. Therefore, it is common that untreated sewage is discharged directly to rivers. In order to recover urine from households and to use them as fertilizer to improve sanitation environment at such places, it is necessary to reduce the volume of urine and cut the cost of collection and transportation. In my study, we use forward osmosis process and investigate the process using magnetic nanoparticles as draw solution.
|Research of the mechanism of inactivated SAP from disposal diaper|
Disposal volume of adult paper diaper is increasing because of an aging in
Japan.However almost paper diapers are not recycled but incinerated.When
pulp, SAP and urinary nutrients recycle from disposal diaper, inactivating
SAP is necessary process. The object of this research is to establish
recycle system of paper diaper by clarifying the mechanism of inactivating
process of SAP by experiment.
|Modelling for Baffled MBR upsizing|
There was a fault such as energy consumption being big for the nitrogen
removal in conventional MBR which both aerobic cistern and anoxic cistern
need, but I partition it off, and nitrification can denitrify it with
single cistern in version insertion type MBR and can realize it with energy
saving, ministry setting area.
For further upsizing of BMBR operating on a pilot scale, I aim at
deciding the details of operating conditions and the device appropriate
effectively by building a model, and performing computer simulation now.
|Investigation of effective CEB condition for flat-type ceramic membrane in
During the operation of MBRs, membrane fouling is an unavoidable problem.
With flat-type ceramic membranes, there is a possibility that membrane
fouling can be efficiently controlled by chemically enhanced backwash
(CEB). It is thought that the effect of CEB changes with the concentration
of chemicals and frequency of input, but there are few examples of studying
these. This study is aimed to investigate CEB conditions that can control
membrane fouling effectively.
|Direct membrane filtration of municipal wastewater for recovery of
Organic matter contained in municipal wastewater can be converted into an
energy resource. But it is difficult to apply anaerobic processes, which
are viable options for producing energy from organic matter in wastewater,
to wastewater because COD concentrations of wastewater is too low. Direct
membrane filtration of municipal wastewater (DMF) can be a solution because
it is a treatment system that can concentrate organic matter effectively.
But it is difficult to operate DMF for a long term due to severe membrane
fouling. So in this study, I investigate operation conditions for membrane