Addition Of Alum Research Articles

Demonstrating Purple Color Development to Students by Showing the Highly Visual Effects of Aluminum Ions and pH on Aqueous Anthocyanin Solutions

Students have long enjoyed color-change demonstrations and experiments. This paper describes the development of purple color in aqueous solutions of anthocyanins by the addition of alum, which enhances the color intensity, and neochlorogenic acid, which enhances the color stability. The range of colors can be further extended with high visual impact by changing the pH of the solutions. Variations of this demonstration are presented that can be adapted for a wide range of educational settings, including using typical anthocyanins to illustrate the chemistry of complexation for undergraduate students (part I); using morning glory flowers to observe a natural dye rainbow suitable for elementary school students; and using different combinations of pH and metal ions to demonstrate coordination complexes for high school students (part II). Follow-up lessons on chemical color stability are possible, given the enduring color of these solutions, even after several months. Suggestions for alternative materials that can be used to conduct these demonstrations are provided to ensure availability for teachers around the world.

FLOCCULANTS OPTIMIZATION IN HARVESTING FRESHWATER MICROALGAE Haematococcus pluvialis

Microalgae-based researches are one of the interesting topics to date due to its wide applications for commercial industries. One of the vital issues that remain in the production of large-scale microalgae is the harvesting process of microalgae culture. There are several techniques that can be used in harvesting microalgae and each algae will be showing a different result. In this research, the microalgae Haematococcus pluvialis were harvested using flocculation-filtration method. Alum in different dosages, range from 0.25-2 g/L, was used as flocculants and the mixing duration was investigated to seek out the best harvesting efficiency. Based on the research, it can be concluded that the optimum flocculation process was alum addition of 1 g/L culture that continuously stirring for 5 minutes long. In which the flocculation efficiency reaches 94.5%.

Insights drawn from a full-scale Intermittently Decanted Extended Aeration (IDEA) plant for optimising nitrogen and phosphorus removal from municipal wastewater

Intermittently Decanted Extended Aeration (IDEA) processes are widely used for wastewater treatment. However, in-depth performance evaluation of a full-scale IDEA plant is rare, making it challenging for water utilities to meet the increasingly stringent discharge requirements with these assets. This study aims to fill this gap through a comprehensive assessment of nitrogen and phosphorus removal in a full-scale IDEA plant in Australia. The plant consists of two identical IDEA tanks operated in-parallel. Upstream to each tank is a bioselector with four interlinked compartments. We conducted an eight-week monitoring program with four intensive cyclic studies to establish detailed nutrient profiles of the two IDEA tanks to assess the performance of nitrogen and alum assisted phosphorus removal. Results showed that the plant enabled good nitrification in the IDEA effluent. However, the denitrification efficiency was low (ca. 50%), and could be improved by decreasing oxygen supply to suppress nitrite oxidation and preserve influent carbon. The addition of alum to the IDEA tank appeared to be ineffective given the low P concentration (<1 mg-P/L) in the tank. The bioselector was identified as a better alum-dosing location, given its higher (~7-fold) phosphate concentration in comparison to the influent. Stopping the dosing of alum only marginally increased the effluent P (0.35 to 0.52 mg-P/L), implying that P removal was predominantly (94%) biologically mediated and achieved via P accumulating microorganisms. Overall, this study offers timely and useful process understanding of the performance of IDEA plants, as well as other similar wastewater treatment configurations.

Enhanced coagulation by two-stage alum addition: the role of solution pH, floc breakage and assistant of non-ionic polyacrylamide

ABSTRACT Coagulation process is highly influenced by solution pH, floc breakage, and coagulant aid. In this work, two-stage addition of alum-based coagulants, polyaluminum chloride (PACl) and aluminum sulfate (Al2(SO4)3), was compared to their one-stage addition with the same total dosage. The dose ratio of primary and secondary addition was optimised. The effects of solution pH, floc breakage and dosing timing of coagulant aid of non-ionic polyacrylamide (NPAM) on coagulation efficiency and floc property were investigated. The results showed that two-stage addition of PACl showed less sensitivity with the variation of pH. Compared to PACl, two-stage addition of Al2(SO4)3 was more sensitive to the solution pH, especially when the pH ranged from 7 to 10. For all cases, the presence of floc breakage improved the removal of colloidal particles. The coagulation mechanism of primary coagulant was charge neutralisation, while other mechanism was involved with the secondary addition of coagulant. Compared to one-stage addition, the settling performance of aggregates and particulates removal in two-stage addition was more effective with the variation of dosage or dosing timing of NPAM. The present work provides detailed operating parameters for this coagulation strategy.

Effect of rapid-mixing conditions on the evolution of micro-flocs to final aggregates during two-stage alum addition

ABSTRACT In a coagulation-flocculation process, optimal separation of the resultant aggregates plays a decisive role on coagulation performance and provides a lower burden for subsequent treatment units. This separation highly depends on the stability of the micro-flocs formed during the initial, rapid stage of coagulation. In this work, a two-stage addition of aluminium sulphate (alum, Al2(SO4)3) was employed by adding 0.04 and 0.08 mM Al2(SO4)3 at the beginning and the end of rapid mixing, respectively. The coagulation performance and floc characteristics were compared to conventional single addition with the same total coagulant dosage, and the effects of variable rapid-mixing speeds (160–850 rpm) and duration time (10–120 s) were investigated. The results showed that the residual turbidity of two-stage coagulant addition was 85.1% lower than single addition when applied at a mixing speed of 580 rpm and a duration time of 120 s. The underlying coagulation mechanism revealed that the two-step addition more effectively neutralized colloids and formed larger aggregates that settled better and could more easily be removed. Moreover, the aggregates were less firm, which was attributed to different interactions among the micro-flocs, the second addition of Al2(SO4)3 and destabilized colloids. The present work provides data to broaden the window of rapid-mixing environments for more effective coagulation.

Effect of Alum (Aluminum Sulfate) Addition to Poultry Litter on Layer Performance, Litter pH and Litter Composition

The current experiment was conducted to assess the effect of using different litter types with or without alum on performance and litter quality of the hen layers. A total number of 120 Inshas layer hens of 24 weeks of age were randomly distributed into 4 groups (3 replicates each 10 hens) of floor litter: T1 birds were raised on wood shaving litter, T2 birds were raised on wheat straw litter, T3 birds were raised wood shaving with 100 g of alum / kg of bedding, and T4 birds were raised on wheat straw litter with 100 g of alum / kg of bedding. Topping of fresh litter with acidifier amendment improved body weight, egg weight, egg number, egg mass, feed intake and feed conversion ratio of layers compared to chickens in the untreated litter group. In comparison with the control group, alum treatment reduced the pH level of the litter. Regarding the NH4+-N content, alum-treated litter showed a higher value than the untreated litter. On average, alum-treated litter had lower P content than the untreated litter. Alum treated group showed a significant increase in dry matter and total nitrogen content when compared with the untreated group. The study results showed significant variability (p &lt; .05) in the moisture content and pH of the control and treated litter. This clearly shows the effectiveness of litter treatment products enhancing litter quality and therefore the bird’s environmental climate. Thus it can be decided that litter modification with alum treatment had a significant impact on litter quality and in turn enhanced the productive performance of layer chickens without any adverse effect.

Mass fluxes of nitrogen and phosphorus through water reclamation facilities: Case study of biological nutrient removal, aerobic sludge digestion, and sidestream recycle.

At water reclamation facilities, recycling of nutrients (nitrogen and phosphorus) from solids-handling processes to the mainstream treatment process can have detrimental effects on biological nutrient removal systems. In this study, mass fluxes of nitrogen and phosphorus were quantified through the treatment trains at the Northwest Regional Water Reclamation Facility (NWRWRF) and the adjoining Biosolids Management Facility (BMF), which receives sludge from several water reclamation facilities in Hillsborough County, Florida. The driving objectives were to determine (a) whether the return stream from BMF to NWRWRF (i.e., the "sidestream") represents a significant source of nitrogen and phosphorus to NWRWRF, and (b) whether the sidestream return from BMF is interfering with biological nutrient removal processes at NWRWRF. We determined that nearly half of the overall phosphorus flux into NWRWRF is recycled from the BMF sidestream. This leads to an increased cost of treatment, for example, for alum used in phosphorus removal at NWRWRF. In contrast to phosphorus, the flux of nitrogen from BMF to NWRWRF is small (~3%) compared with the flux of nitrogen entering NWRWRF in raw wastewater. However, nitrogen in the sidestream is mostly in the form of nitrate, which prevents anaerobic conditions from developing in the fermentation basin at NWRWRF, and thereby interferes with the enhanced biological phosphorus removal (EBPR) process. Some measurements suggest that fermentation and release of phosphorus may occur in the return activated sludge line (despite the relatively short residence time in that line), which supports EBPR and may partially compensate for anoxic (denitrifying) conditions in the fermentation basin. Therefore, overall, NWRWRF is able to meet its permit limits for phosphorus through a combination of EBPR and alum addition. Although the fluxes measured here are particular to the treatment systems under consideration, the general trends observed are likely to apply to many similar facilities that employ biological nutrient removal, aerobic digestion, and sidestream recycle, particularly those with regional biosolids management facilities. We recommend that such facilities consider (a) removal or recovery of phosphorus from their sidestreams and (b) returning sidestreams downstream of fermentation basins to avoid inhibition of EBPR processes. PRACTITIONER POINTS: Sidestreams from aerobic digestion can represent significant sources of phosphorus to mainstream wastewater treatment. Recycle of nitrate in aerobic digestion sidestreams can interfere with enhanced biological phosphorus removal (EBPR) during mainstream treatment. Fermentation of return activated sludge (RAS) can support EBPR, even under short average hydraulic residence times (minutes).

Compaction performance analysis of alum sludge waste modified soil

Sustainable construction is one of the ultimate requirements of the engineering field. Addition of waste materials not only contribute to the improvement of the density of soils but also help in the enhancement of its strength properties. In the field, compaction is achieved by compactors and rollers, which consumes a lot of energy for this purpose. In this study, two methods related to compaction energy have been applied to study the relation of compaction energy with the strength of soil before and after addition of alum sludge as a soil stabilizer. An advanced Artificial Neural Networks (ANNs) technique has been applied with reference to the addition of alum sludge percentage, plasticity index, specific gravity, optimum moisture content, maximum dry density, AASHTO classification, USCS classification, and group index. It was found that soil strength can be improved even at a low compaction energy level of 600KN-m/m3 by the addition of optimum percentage of 8% alum sludge as a soil stabilizer. So, roller compaction effort can also be reduced by addition of this soil stabilizer to save compaction cost i.e. saving of roller fuel consumption and rental cost as well. This study will not only help in environment-friendly construction but will also manage finance by utilization of optimum compaction energy in the mega projects.

The effect of alum addition on shrinkage temperature, chemical properties, and morphology in the manufacture of vegetable-tanned leather

Vegetable-tanned leather has several disadvantages, which one of them is low thermal stability due to insufficient cross-linking with the collagen. The addition of aluminum sulfate in the vegetable tanning process will strengthen the cross-linking between the polyphenol and collagen, as well as forms the matrix in collagen. Thus, it will improve the thermal stability. The research aimed to figure out the addition of mimosa and aluminum sulfate on the shrinkage temperature, chemical properties, and morphology of leather. The research was conducted by using a variation of mimosa concentration (15%, 20%, 25% w/w) and aluminium sulfate concentration (3%, 6%, 9% w/w). The results showed that the treatment influenced the chemical properties and shrinkage temperature. The optimum treatment was the addition of 9% (w/w) aluminium sulfate to 25% mimosa which resulted to shrinkage temperature of 99,33° (rise 18,34%); nitrogen content (8,00 ± 0,0141)%; raw skins substance content (44,46 ± 0,0778)%; tannin bound content (28,29 ± 0,0424)% and the degree of tannage (62,93 ± 0,0141)%. Based on the SEM image, the addition of aluminum sulfate after mimosa has made the collagen fiber structure to be dense, which indicates the improvement of the cross-linking between the polyphenol and collagen.

STUDY OF GUAR GUM, ALUM, AND WATER ADDITION ON PHYSICAL CHARACTERISTICS OF EXTRUDED WET CORN NOODLE

Corn noodle was a form of food diversification, especially food that usually used wheat flour as its raw material. The objective of this research was to study the effects of guar gum, alum, and water addition on physical properties of extruded wet corn noodle. It was made by mixing wet and dried flours, steaming dough, pressing it using an paste extruder, and steaming the noodles. The alum, guar gum, and water concentrations were 0% and 0.01%; 0%, 1%, and 2%; and 60%, 70%, and 80%, respectively. The physical analysis of wet corn noodle were color, elongation, hardness, adhesiveness, and cooking loss analysis. The analysis showed that wet corn noodles have a reddish yellow color with °Hue of 83.21° - 86.42°. The statistical analysis showed that the higher the guar gum concentration led to the lower the hardness and cooking loss of wet corn noodle, while the greater the elongation. Alum addition increased the hardness and elongation of wet corn noodles, while it decreased the adhesiveness.

The Effectiveness of Alum from some Nigerian Kaolinites in Water Treatment

Alum is a useful product in both leather tanning and water treatment purposes where it serves as a coagulant and disinfectant. High quality alum has recently been produced from some Nigerian kaolinite (Bauchi and Kankara) via the energy-saving process. This process utilizes the heat generated when sulfuric acid is mixed with water to dealuminate the metakaolin, instead of the usual application of external heat source. This study focuses on testing their effectiveness in actual water treatment process in comparison with a commercial alum. Several parameters of the raw water and 50 to 300 ppm of alum-raw water solution were measured to determine the effects of the alum addition. The influence of both alums was found to be strikingly similar. While the total dissolved solids (TDS) and conductivity increased with alum concentration, the biological oxygen demand (BOD), chemical oxygen demand (COD), and alkalinity of the water showed reduction. The coagulating effectiveness of both alums was demonstrated by over 95% reduction in the turbidity of the raw water sample. The results also revealed that the alum from Nigerian kaolinites showed remarkable and desirable water treatment qualities and compares well with the commercial alum for all the tested parameters. The development of alum production plant using Nigerian kaolinite is therefore recommended as it can serve as alternative to the present commercial alum that is majorly imported.

Effect of potassium alum addition on the quality of potato starch noodles.

The objective of this study was to investigate the effects and mechanism of potassium alum (PA) on potato starch noodles to provide a theoretical basis for future searches for new alternatives for PA that are not harmful to the body. The amount of amylose leakage significantly decreased with the PA addition. SEM showed that the honeycomb structure of potato starch noodles with 0.1% PA was diminished. The number of internal pores and average area decreased from 92 and 580.09 units to 72 and 652.58 units, respectively. NMR indicated that the water holding capacity of potato starch noodles containing PA was greater than that of the control. XRD showed that the crystal structure of potato starch noodles was destroyed and that the crystallinity of potato starch noodles with PA increased from 16.65 to 19.64%. G' and G'' increased, but tanδ decreased. FT-IR showed that PA caused the O-H stretching vibration in the absorption peak to move in the high-field direction and that the ionic bond was dominant in the PA-potato starch interaction system.

Treatment of Waste Water Using Natural Coagulants

The use of natural coagulants like Moringa Oleifera and Okra plants are receiving attention for their effectiveness in waste water treatment. The technologies involved are economical, traditional and easy to implement and ideal for rural areas. The process being biological in nature does not generate any non-treatable wastes. These processes are easy to operate and require little or no maintenance. After the treatment of both the municipal and dairy waste water samples by two natural coagulants Moringa Oleifera and Okra seeds and synthetic coagulant alum, the results show that there is a reduction in the percentage of various polluting parameters like COD, BOD, turbidity, hardness, TSS and TDS etc. In the study different quantity of coagulants doses (50 mg, 200 mg, and 500 mg) were used but it is found that increasing the amount of coagulant increases the removal but it is not proportional and significant with respect to the quantity of coagulant added. By the effect of Moringa Oleifera coagulant the reduction of turbidity, COD, BOD, hardness, TSS and TDS are found to be 61.20 %, 65.3 %, 55 %, 25 %, 69 %, and 68% respectively. There is not much effect on the pH. By the effect of Okra coagulant, the reduction in percentages of turbidity, COD, BOD, hardness, TSS, and TDS are found to be 65 %, 67 %, 56 %, 30 %,72 %, and 69 % respectively. There is no significant change in pH due to natural coagulants. By the effect of alum coagulant the reduction percentages of turbidity, COD, BOD, hardness, TSs, and TDS are found to be 59 %, 59 %, 50.98%, 67 %, and 65 % respectively. The addition of alum makes the water more acidic.

Effect of ammonia stripping and use of additives on separation of solids, phosphorus, copper and zinc from liquid fractions of animal slurries

To increase the sustainable reuse of animal manure as fertiliser, in many cases suitable treatment techniques are needed to modify the composition and obtain a balanced nutrient content. This study was conducted to evaluate the best strategies to remove solids, P, Cu and Zn, using two additives Ca(OH)2 and Al2(SO4)3, in combination with an ammonia stripping process. The assessment was carried out on five type of liquid fractions derived from the mechanical separation of: raw pig slurry, pig digested slurry, pig digested slurry after ammonia stripping, pig and cattle digested slurry, pig and cattle digested slurry after ammonia stripping. After the addition of the chemicals, the liquid fractions were mixed and then separated using a static filter. The contents of total solids P, Cu and Zn were determined. The additives effectively improved separation efficiencies which depended on the type of slurry and additive used. The P separation efficiencies ranged from 72% to 93% using Al2(SO4)3, and from 20 to 74% using Ca(OH)2. The use of Al2(SO4)3 always had a more consistent effect on the removal efficiencies than Ca(OH)2. The ammonia stripping process, reducing the alkalinity of the digested liquid fractions, facilitated a higher concentration of elements in the separated fraction. With the addition of Al2(SO4)3 to digestate after stripping the concentration of P, Cu and Zn in the solid fraction generally increased when compared to the same liquid fraction without stripping. The addition of Ca(OH)2 might be effective in removing P before the stripping process with the additional benefit to raise pH and improve the ammonia removal efficiency. These findings indicate that solid-liquid separation of animal manure slurries, assisted by chemical additives and coupled with ammonia stripping, can be a viable option for improving the sustainable use of animal manure as a fertiliser.

Strategic differences in phosphorus stabilization by alum and dolomite amendments in calcareous and red soils.

Surplus phosphorus (P) above agronomic requirements can negatively affect the water status of connected surface and subsurface water bodies. The in situ stabilization of soil P through soil amendment has been recognized as an efficient way to reduce this environmental pressure. However, the mechanism of how P is stabilized during this process and how plant available P is affected are unknown. This can be achieved by sequential chemical extraction and synchrotron-based X-ray absorption near-edge structure (XANES) spectroscopy investigations. Therefore, in the present study, P-enriched calcareous and red soils were amended with alum, dolomite, and a 1:1 mixture of alum and dolomite (MAD) at a 20g/kg soil rate, and soil properties and P fractions were measured after a 45-day period. Results showed that alum amendment significantly decreased CaCl2-P and Olsen-P contents in calcareous and red soils when compared with dolomite. However, dolomite incorporation maintained relatively high P availability and even increased CaCl2-P and Olsen-P contents by 1.32% and 40.5% in red soil, respectively, compared to control. Amendment with MAD was not as effectively as the alum in P stabilization. Sequential inorganic P extraction indicated that alum dominantly contributed labile P transformed to Al-P in both soils. P K-edge XANES spectroscopy measurements further explained that alum adsorbed phosphate in calcareous soil and precipitated phosphate as AlPO4 in red soil. Results of P fractionation and Mehlich-3-extracted Ca showed that dolomite mainly adsorbed loosely bound P in calcareous soil and red soil. However, dolomite incorporation in red soil led to Al-P and Fe-P release. The P sorption isotherms showed that dolomite and alum increased soil P sorption maxima and decreased the degree of P saturation (DPS) in both soils, while dolomite declined the Langmuir bonding energy in red soil. Differences in P stabilization by alum and dolomite addition across soil types were closely related to their characteristics, and soil properties changed, especially soil pH.

Effect of multiple chemical activators on mechanical property of high replacement high calcium fly ash blended system

Although the alkali activation of high calcium fly ash has been well studied, there is limited research has been conducted about the activation with carbonates and aluminum sulfates in the high replacement high calcium fly ash blended system. In this study, the activation effect of four types of chemical activators (Li2CO3, Na2CO3, K2CO3 and Al2(SO4)3) on the mechanical property was researched, and the high replacement of high calcium fly ash was kept as 50%. The activation mechanisms were revealed by the analyses of the non-evaporated water content, the reaction degree of fly ash and the hydration products. It was found that the addition of Li2CO3 was more effective to enhance the compressive strength development and reduce the setting time of the blended mixture due to distinct acceleration of hydration of cement with more formation of C-S-H. Due to the effective promotion of hydration of cement and activation of pozzolanic reaction by the addition of Al2(SO4)3, the combination of 0.6% Li2CO3 and 0.6% Al2(SO4)3 was used to obtain the superior mechanical property, and the mechanism of which was also proposed that the existence of the LiAl2(OH)7·2(H2O) and Li2SO4·H2O might induce the precipitation of amorphous Li-containing C-S-H and that would act as the seeds for the nucleation of C-S-H, so that the compressive strength development would be faster. However, the above hypothesis requires further research to confirm it.

Development of statistical models for trihalomethane (THM) removal in drinking water sources using carbon nanotubes (CNTs)

This research developed models using the multiple linear regression technique for prediction of trihalomethane (THM) removal from chlorinated drinking water sources through a combination of a coagulation process with carbon nanotubes (CNTs). Terkos Lake water (TLW), Buyukçekmece Lake water (BLW) and Ulutan Lake water (ULW) samples were coagulated by a conventional coagulant (alum) and increasing doses of single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs) with the addition of alum. Also, chlorination experiments were conducted with water reservoirs from TLW, BLW and ULW, with different water quality regarding bromide concentration and organic matter content. The factors studied affecting THM removal were contact time, chlorine dose, coagulation process, total organic carbon (TOC), and specific ultraviolet absorbance (SUVA). Statistical analysis of the results focused on the development of multiple regression models, as Models 1 and 2, for predicting total trihalomethane (TTHM) based on the use of contact time, SWCNTs and MWCNTs doses, chlorine dose and TOC. When the two models were compared, Model 1 proved best suited to describe THM removal for the three water sources. The developed models provided satisfactory estimations of THM removal; the model regression coefficients for Models 1 and 2 were 0.88 and 0.77, respectively. Furthermore, the root-mean-square error (RMSE) values of 0.083 and 0.126 confirm the reliability of the two models. The results show that THM removal can be simply predicted by using the multiple linear regression technique in chlorinated drinking water sources.

Phosphorus Leaching from Soil Cores from a Twenty-Year Study Evaluating Alum Treatment of Poultry Litter.

Adding alum to poultry litter is a best management practice used to stabilize P in less soluble forms, reducing nonpoint-source P runoff. However, little research has been conducted on how alum additions to litter affect subsequent leaching of P from soil. The objective of this study was to evaluate the effects of alum-treated versus untreated poultry litter on P leaching from soil cores receiving long-term poultry litter applications. Two intact soil cores were taken from each of 52 plots in a long-term study with 13 treatments: a control, four rates each of untreated and alum-treated litter (2.24, 4.49, 6.72, and 8.96 Mg ha), and four rates of ammonium nitrate (65, 130, 195, and 260 kg N ha). One core from each plot received the same fertilizer as for the previous 20 yr, whereas the other was unfertilized in the study year, resulting in a total of 25 treatments. Cores were exposed to natural rainfall, and P leaching was measured for 1 yr. The average soluble reactive P concentrations in the leachate varied from 0.16 to 0.44 mg P L in fertilized alum-treated cores, whereas leachate from cores fertilized with untreated litter ranged from 0.40 to 2.64 mg P L. At the highest litter rate (8.96 Mg ha), alum reduced total dissolved P and total P concentrations in leachate by 83 and 80%, respectively, compared with untreated litter. These results indicate that alum additions to poultry litter significantly reduced soluble and total P fractions in leachate.

Utilization of phosphogypsum for the preparation of α‐calcium sulfate hemihydrate in chloride‐free solution under atmospheric pressure

AbstractBACKGROUNDThis work aims to investigate the possibility of recycling by‐product phosphogypsum (PG) as raw material for preparing α‐calcium sulfate hemihydrate (α‐CSH) in chloride‐free salt solution under mild conditions. The dehydration of PG in a concentrated Ca(NO3)2 solution at 97 °C under atmospheric pressure was analyzed. The effect of Al2(SO4)3 on the phase‐transition kinetics as well as succinic acid concentration on the crystal morphology of α‐CSH were investigated in detail.RESULTSα‐CSH was successfully prepared from PG in 3.7 mol L‐1 Ca(NO3)2 solution at 97 °C under atmospheric pressure. Addition of Al2(SO4)3 accelerates dehydration rate of PG and decreases crystal size of α‐CSH. Moreover, succinic acid is an effective morphology modifier for α‐CSH. When the reaction is carried out with 5.84 mmol L‐1 Al2(SO4)3 and 0.15 wt% succinic acid, the α‐CSH obtained has aspect ratio of 1.2, and the corresponding paste shows enhanced 3D bending/compressive strengths of 11.3/41.7 MPa, which are comparable with those of commercial α‐CSH.CONCLUSIONSThis chloride‐free system provides an improved alternative for preparing high quality α‐CSH, and helps to promote value‐added utilization of PG. © 2018 Society of Chemical Industry

Use of Tectonagrandis Leaf Extract in Colouring Silk Cloth Material Based on pH and Mordant Variations

One of the very potential use of plant natural colour in the industrial activities was Anthocyanin. This substance contains in a number on plant organs such as Tectona Grandis (Fabaceae) particularly in their leaf materials. In order to get this secondary metabolism, the aim of this research was to find out the optimum condition of mordant and the pH combination in producing natural colour of Tectonagrandis leaf extract. To get this chemical substance, 1 kilogram of young leaves were cut into smaller size and soaked in 7 litre of H2O for 12 hour9. The solution was then boiled for 15 minutes. To get the best colour, variations of pH (5, 7 and 9) respectivelly were applied. The results showed that purple to redness were resulted when pH 5 and no additional mordant was added. Conversly the greyness to black, were produced when ferrosulphate were added. When the addition of alum was made the redies purple will appear. These colours were considered quite good quality under examination of grey and staining scales (4-5) after treated by both wet and dry rubbing methods. The test for wash fastness resulted in sufficiently good value of color change (value of 3 on Grey Scale standard), while test for staining demonstrated good staining (value of 4 on Staining Scale standard). This early finding was quite promosing to be applied in the near future in providing natural colours for industrial purposes.