S. Muryanto

Publications (13) View all

• Article: Phosphorus recovery from agroindustrial wastewater through struvite crystallisation: principles and applications

  S. Muryanto, A.P. Bayuseno, E. Supriyo, B. Hermanu
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  ABSTRACT: Intensified agriculture has often led to excessive nutrient discharges into water bodies causing eutrophication. An attractive method to help minimise eutrophication is to remove phosphorus (P) from wastewater by crystallising it into a phosphate mineral (MgNH4PO4.6H2O), commonly known as struvite. Due to its low solubility in water, struvite can be utilised as slow-release fertilizer. P removal and recovery as struvite is also an effective means to address the persistent problem of scale formation in wastewater treatment facilities. This paper discusses the change in morphology of struvite crystals obtained from synthetic liquors, as affected by two major ions commonly found in agroindustrial wastewater: Cu2+ and Zn2+. The principles of P recovery from agroindustrial wastewater through struvite crystallisation, and operation of a typical commercial-scale struvite crystallisation project are also presented.
  Journal of Agricultural Science and Technology. 01/2012; 2(4A).
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  Article: Wastewater Treatment for a Sustainable Future: Overview of Phosphorus Recovery

  S. Muryanto, A.P. Bayuseno
  Applied Mechanics and Materials. 01/2012; 110-116:2043-2048.
• Article: Development of a versatile laboratory project for scale formation and control

  S. Muryanto, A.P. Bayuseno, W. Sediono, W. Mangestiyono, Sutrisno
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  ABSTRACT: Development of a laboratory rig to provide graduate students with versatile equipment for final year projects is discussed in this paper. The laboratory demonstrated scale formation and control in pipes, a persistent problem encountered in many industries. As a sample study, the laboratory has been used to investigate the influence of four parameters on the formation and prevention of calcium sulphate dihydrate (gypsum) scale. These parameters were: concentration of solutions, fluid flow rates, temperature, and presence of additives. This laboratory project has been successfully implemented in the Mechanical Engineering Graduate Program at Diponegoro University. Since the results of the sample study agree well with the literature, the present laboratory would be of importance for final year projects concerning crystallization and its practical implications in scale formation and control. Wider utilization of the laboratory, including training in scale prevention for industry, has been planned.
  Education for Chemical Engineers 01/2012; 7(3):e78-e84.
• Conference Proceeding: Growth of calcium sulphate scale minerals in vessels and pipes: a comparison study of the influence of scale inhibitors

  Stefanus Muryanto
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  ABSTRACT: Scale formation on equipment surfaces and piping systems is one of the persistent problems encountered in many industrial operations such as evaporation, mixing, crystallisation, and heating and cooling of liquids. The scale formation and its subsequent deposition reduces the capacity of production through resistance to heat transfer and restriction of materials flow, thus increasing energy requirement. This paper presents an investigation on the formation and growth of calcium sulphate-based scale, namely gypsum, inside pipes of different materials: PVC, brass, copper and stainless steel. Effects of supersaturation, type and dosage of scale inhibitors, fluid velocity, and type of piping materials on the scaling rate were examined. The growth of these gypsum scale was compared with that of gypsum crystals grown in a seeded continuous MSMPR crystalliser. The scaling experiments showed that the mass of the gypsum scale deposited over a fixed period increases with the supersaturation of the scaling solutions, and that the correlation between the mass and the supersaturation can be represented by quadratic functions. Further, the deposited scale mass decreases with increasing concentration of the scale inhibitors used. It was also found that the flow rate of the solutions inside the pipes has no significant effect on the scale deposit. In addition, the amount of the scale deposit was highest on PVC, followed by brass and copper, and lowest on stainless steel. The MSMPR crystallisation experiment was initially started in a batch mode for one residence time of 15 minutes. When the batch mode period was ended, the system was run in a continuous mode uninterrupted for up to eight residence times to ensure that the system reached steady state. The MSMPR experiments revealed that the growth rate of gypsum crystals is dependent on crystal size, and a correlation between these two parameters and the inhibitor concentrations can be formulated as G = k Lα (1+C)β, where G: linear growth rate, (micron/hour), k, α and β: dimensionless constants, L: crystal size, (micron), and C: concentration of inhibitors, (ppm). The attempt to compare the rate of gypsum scale formation inside pipes and the growth rate of gypsum crystals in the crystalliser appears to be quantitatively reasonable. In the absence of scale inhibitors the rate of growth of crystals in the crystalliser is consistently higher than the scale formation in the scaling system, regardless of the flow velocity of the scaling solutions. Keywords: calcium sulphate, crystals, MSMPR, piping systems, scale inhibitors.
  The 3rd Sriwijaya International Seminar on Energy Science and Technology (SISEST) 2010, Sriwijaya University, Palembang, INDONESIA; 01/2010
• Conference Proceeding: Struvite scale formation and control. A review

  Stefanus Muryanto
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  ABSTRACT: Scale formation is one of the pertinent problems in wastewater treatment and related industries. One of the main components of the scale is frequently struvite or crystals of magnesium ammonium phosphate hexahydrate (MgNH4PO4.6H2O). Struvite crystallises along supernatant recirculation piping especially at the elbows and the suction side of pumps. It also occurs in the sludge derived from anaerobic processing of animal and agricultural wastes. Struvite crystallisation and its subsequent deposition on equipment surfaces and piping systems increase the energy required for pumping as well as the cost associated with maintenance and replacement of parts. Thus, the operational and technical problems eventually translate into substantial economic penalties. At the same time, struvite is a sparingly soluble mineral and considered potential as an alternative slow-release fertilizer. Hence, struvite crystallisation has been an extensive area of research. Struvite precipitates as stable white orthorhombic crystals according to the following reaction: Mg2+ + NH+ + HnPO4n-3 + 6 H2O → MgNH4PO4.6H2O + nH+ Depending on the pH, n may equal 0, 1 or 2. Industrially, scale formation occurs in an environment which is very rarely free from the presence of admixtures. The effects of admixtures on crystallisation kinetics and crystal morphology, hence on scale formation, can be very significant even if the admixtures are present in trace amounts. While research on the effects of admixtures on struvite precipitation has been extensive, the effects are mostly specific that there is no unified theory that applies to all and every situation. This paper presents a comprehensive review on struvite precipitation kinetics focusing on the effects of admixtures on struvite scale formation and control. Results of laboratory work on induction time of struvite crystallisation is also presented and scrutinized.
  International Conference on Sustainable Built Environment (ICSBE) 2010, Indonesian Islamic University, Yogyakarta, Indonesia; 01/2010