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1.
BMJ Open ; 8(3): e018430, 2018 03 27.
Article in English | MEDLINE | ID: mdl-29593017

ABSTRACT

INTRODUCTION: This trial proposes to compare the effectiveness and cost-effectiveness of electroacupuncture (EA) plus on-demand gastrocaine with waiting list for EA plus on-demand gastrocaine in providing symptom relief and quality-of-life improvement among patients with functional dyspepsia (FD). METHODS AND ANALYSIS: This is a single-centre, pragmatic, randomised parallel-group, superiority trial comparing the outcomes of (1) EA plus on-demand gastrocaine group and (2) waiting list to EA plus on-demand gastrocaine group. 132 (66/arm) endoscopically confirmed, Helicobacter pylori-negative patients with FD will be recruited. Enrolled patients will respectively be receiving (1) 20 sessions of EA over 10 weeks plus on-demand gastrocaine; or (2) on-demand gastrocaine and being nominated on to a waiting list for EA, which entitles them 20 sessions of EA over 10 weeks after 12 weeks of waiting. The primary outcome will be the between-group difference in proportion of patients achieving adequate relief of symptoms over 12 weeks. The secondary outcomes will include patient-reported change in global symptoms and individual symptoms, Nepean Dyspepsia Index, Nutrient Drink Test, 9-item Patient Health Questionnaire (PHQ9), and 7-item Generalised Anxiety Disorder Scale (GAD7). Adverse events will be assessed formally. Results on direct medical costs and on the EuroQol (EQ-5D) questionnaire will also be used to assess cost-effectiveness. Analysis will follow the intention-to-treat principle using appropriate univariate and multivariate methods. A mixed model analysis taking into account missing data of these outcomes will be performed. Cost-effectiveness analysis will be performed using established approach. ETHICS AND DISSEMINATION: The study is supported by the Health and Medical Research Fund, Government of the Hong Kong Special Administrative Region of China. It has been approved by the Joint Chinese University of Hong Kong - New Territories East Cluster Clinical Research Ethics Committee. Results will be published in peer-reviewed journals and be disseminated in international conference. TRIAL REGISTRATION NUMBER: ChiCTR-IPC-15007109; Pre-result.


Subject(s)
Aluminum Hydroxide/therapeutic use , Aminobenzoates/therapeutic use , Atropine/therapeutic use , Cost-Benefit Analysis/economics , Dyspepsia/therapy , Electroacupuncture/methods , Magnesium Compounds/therapeutic use , Research Design , Standard of Care/economics , Adolescent , Adult , Aged , Aluminum Hydroxide/economics , Aminobenzoates/economics , Atropine/economics , Drug Combinations , Dyspepsia/economics , Electroacupuncture/economics , Female , Hong Kong , Humans , Magnesium Compounds/economics , Male , Middle Aged , Patient Satisfaction , Quality of Life , Surveys and Questionnaires , Treatment Outcome , Waiting Lists , Young Adult
2.
Environ Technol ; 36(13-16): 1892-901, 2015.
Article in English | MEDLINE | ID: mdl-25704607

ABSTRACT

Deliberate struvite (MgNH4PO4) precipitation from wastewater streams has been the topic of extensive research in the last two decades and is expected to gather worldwide momentum in the near future as a P-reuse technique. A wide range of operational alternatives has been reported for struvite precipitation, including the application of various Mg(II) sources, two pH elevation techniques and several Mg:P ratios and pH values. The choice of each operational parameter within the struvite precipitation process affects process efficiency, the overall cost and also the choice of other operational parameters. Thus, a comprehensive simulation program that takes all these parameters into account is essential for process design. This paper introduces a systematic decision-supporting tool which accepts a wide range of possible operational parameters, including unconventional Mg(II) sources (i.e. seawater and seawater nanofiltration brines). The study is supplied with a free-of-charge computerized tool (http://tx.technion.ac.il/~agrengn/agr/Struvite_Program.zip) which links two computer platforms (Python and PHREEQC) for executing thermodynamic calculations according to predefined kinetic considerations. The model can be (inter alia) used for optimizing the struvite-fluidized bed reactor process operation with respect to P removal efficiency, struvite purity and economic feasibility of the chosen alternative. The paper describes the algorithm and its underlying assumptions, and shows results (i.e. effluent water quality, cost breakdown and P removal efficiency) of several case studies consisting of typical wastewaters treated at various operational conditions.


Subject(s)
Fractional Precipitation/economics , Fractional Precipitation/instrumentation , Magnesium Compounds/economics , Phosphates/economics , Waste Disposal, Fluid/economics , Water Purification/economics , Algorithms , Computer Simulation , Computer-Aided Design , Equipment Design , Equipment Failure Analysis , Israel , Magnesium Compounds/chemistry , Magnesium Compounds/isolation & purification , Models, Chemical , Phosphates/chemistry , Phosphates/isolation & purification , Struvite , Waste Disposal, Fluid/instrumentation , Water Pollutants, Chemical/chemistry , Water Pollutants, Chemical/economics , Water Pollutants, Chemical/isolation & purification , Water Purification/instrumentation
3.
J Oleo Sci ; 61(12): 729-36, 2012.
Article in English | MEDLINE | ID: mdl-23196874

ABSTRACT

In this study, natural Iraqi low- cost locally available clay (palygorskite) was studied for its potential use as an adsorbent for removal Congo red from aqueous solutions. Batch type experiments were conducted to study the effect of contact time, initial pH of the dye solution, initial dye concentration, adsorbent dosage, and particle size of adsorbent on adsorption capacity of Congo red. The adsorption occurred very fast initially and attains equilibrium within 60 min. When the effect of pH of solution dye on the yield adsorption has been carried in a range of 2-10, the adsorption obtained was nearly the same with very slightly effect of pH and it was reported that above 49.07 mg/g of Cong red by palygorskite clay occurred in the pH range 2 to 10. It was observed that the removal of Congo red increase with increasing initial dye concentration and adsorbent dose, but, adsorption capacity decrease with increasing adsorbent dose. The adsorption capacity increase with decreasing particle size of adsorbent. The equilibrium adsorption data were interpreted using Langmuir and Freundlich isotherm models. The obtained results revealed that the equilibrium data closely followed both models, but the Langmuir isotherm fitted the data better. The maximum adsorption capacity was found to be 99 mg/g at ambient temperature. Results indicate that Iraqi palygorskite clay could be employed as a low cost alternative to commercial activated carbon in wastewater treatment for the removal of colour and dyes.


Subject(s)
Aluminum Silicates/chemistry , Aluminum Silicates/economics , Congo Red/chemistry , Congo Red/isolation & purification , Industrial Waste , Magnesium Compounds/chemistry , Magnesium Compounds/economics , Silicon Compounds/chemistry , Silicon Compounds/economics , Wastewater/chemistry , Adsorption , Clay , Costs and Cost Analysis , Hydrogen-Ion Concentration , Iraq , Molecular Structure , Surface Properties , Temperature
4.
Water Res ; 45(2): 852-62, 2011 Jan.
Article in English | MEDLINE | ID: mdl-20980038

ABSTRACT

This research investigated the possibility of transferring phosphorus from human urine into a concentrated form that can be used as fertilizer in agriculture. The community of Siddhipur in Nepal was chosen as a research site, because there is a strong presence and acceptance of the urine-diverting dry toilets needed to collect urine separately at the source. Furthermore, because the mainly agricultural country is landlocked and depends on expensive, imported fertilizers, the need for nutrient security is high. We found that struvite (MgNH(4)PO(4)·6H(2)O) precipitation from urine is an efficient and simple approach to produce a granulated phosphorus fertilizer. Bittern, a waste stream from salt production, is a practical magnesium source for struvite production, but it has to be imported from India. Calculations show that magnesium oxide produced from locally available magnesite would be a cheaper magnesium source. A reactor with an external filtration system was capable of removing over 90% of phosphorus with a low magnesium dosage (1.1 mol Mg mol P), with coarse nylon filters (pore width up to 160±50 µm) and with only one hour total treatment time. A second reactor setup based on sedimentation only achieved 50% phosphate removal, even when flocculants were added. Given the current fertilizer prices, high volumes of urine must be processed, if struvite recovery should be financially sustainable. Therefore, it is important to optimize the process. Our calculations showed that collecting the struvite and calcium phosphate precipitated spontaneously due to urea hydrolysis could increase the overall phosphate recovery by at least 40%. The magnesium dosage can be optimized by estimating the phosphate concentration by measuring electrical conductivity. An important source of additional revenue could be the effluent of the struvite reactor. Further research should be aimed at finding methods and technologies to recover the nutrients from the effluent.


Subject(s)
Fertilizers/economics , Magnesium Compounds/chemical synthesis , Phosphates/chemical synthesis , Phosphorus/urine , Adolescent , Adult , Agricultural Irrigation , Child , Female , Filtration , Flocculation , Humans , Magnesium Compounds/economics , Magnesium Oxide , Male , Middle Aged , Nepal , Phosphates/economics , Phosphates/urine , Struvite , Waste Disposal, Fluid/instrumentation , Waste Disposal, Fluid/methods , Water Purification/methods
5.
Water Res ; 36(7): 1834-42, 2002 Apr.
Article in English | MEDLINE | ID: mdl-12044083

ABSTRACT

Formation of struvite (MgNH4PO4 x 6H2O) at sewage treatment works can cause operational problems and decrease efficiency. Struvite has a commercial value and the controlled formation and recovery of it would be beneficial. A mass balance was conducted at full scale across the whole sewage treatment plant in order to identify a stream to conduct bench-scale struvite crystallisation studies. The most suitable stream was identified as the centrifuge liquors. The average flow of the liquor stream was 393 m3 d(-1) and the composition was as follows: 167 mg L(-1) phosphorus, 44 mg L(-1) magnesium, 615 mg L(-1) ammonium, 56 mg L(-1) calcium and 2580 mg L(-1) of alkalinity. The pH averaged at 7.6 and the stream had a predicted struvite precipitation potential of 140 mg L(-1). Struvite crystallisation occurred quickly during the trials, by raising the pH of the centrifuge liquors to 9.0 and dosing with magnesium. Up to 97% phosphorus removal as struvite was achieved. Struvite formation occurred when the molar ratio of magnesium:phosphorus was at least 1.05:1. Below this ratio phosphorus removals of 72% were observed, but not exclusively as struvite. Annual yields of struvite were calculated to be 42-100 tonnes a year, depending on the dose regime. Revenue from the sale of produced struvite could be between Pound Sterling8400 and Pound Sterling20,000 a year.


Subject(s)
Magnesium Compounds/chemistry , Magnesium Compounds/isolation & purification , Phosphates/chemistry , Phosphates/isolation & purification , Phosphorus/isolation & purification , Water Purification , Costs and Cost Analysis , Crystallization , Hydrogen-Ion Concentration , Magnesium/chemistry , Magnesium Compounds/economics , Phosphates/economics , Pilot Projects , Sewage/chemistry , Struvite , Water Purification/economics
6.
Environ Technol ; 22(11): 1373-81, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11804359

ABSTRACT

The adoption of phosphorus removal at sewage treatment works (STW) creates two main problems. Firstly large amounts of sludge are produced and secondly the quantity of the effluent deteriorates due to the increase in the phosphorus load of the sidestream. Furthermore, these processes do not remove phosphorus in a form that would enable it to be recycled. Therefore in order to control these process difficulties and produce a recyclable phosphorus product a sidestream struvite crystallisation reactor was developed. The struvite was produced in a fluidised bed reactor using dewatered filtrate from anaerobic sludge digestion. Magnesium hydroxide was added in a magnesium to phosphate ratio of 1:1 and the pH was adjusted to between 8.2-8.8 with the addition of sodium hydroxide. A retention time of 10 days alowed the growth of pellets between 0.5-1.0 mm in size. The recovered struvite contained only minute traces of toxic substances and was sold to fertiliser companies for 27,000 yen tonne(-1). It is used to enhance existing fertilisers, which are widely used on paddy rice, vegetables and flowers.


Subject(s)
Agriculture , Conservation of Natural Resources , Hemostatics/chemistry , Magnesium Compounds/chemistry , Phosphates/chemistry , Phosphorus/chemistry , Waste Disposal, Fluid/methods , Commerce , Fertilizers , Hemostatics/economics , Magnesium Compounds/economics , Phosphates/economics , Quality Control , Sewage , Struvite , Time Factors
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