Commercial Coagulants Research Articles

Effects of crab shell extract as a coagulant on the textural and sensorial properties of tofu (soybean curd).

To find an economic use of red snow crab (Chionoecetes japonicus) shell waste, we focused on its high mineral content. To evaluate its usability as a coagulant for tofu making, the effects of the crab shell extracts on the textural and sensorial properties of the tofu samples were investigated. The crab shell powder (CSP) and ash (CSA) were used for their extract preparation, and 1%–5% acetic acid treatment led to an abundance of calcium in the resulting extracts. The tofu yields of all the acetic acid extracts were comparable with those of the commercial coagulants MgCl2 and glucono‐δ‐lactone (GDL). Furthermore, the results for the textural attributes and sensorial acceptability demonstrated that either the extract from CSP prepared with 3% acetic acid or the extracts from CSA prepared with 1% or 3% acetic acid could be used as coagulants, because all the values of the extracts were statistically equivalent to those of the MgCl2 and GDL (p < 0.05).

Study of Sludge Particles Formed during Coagulation of Synthetic and Municipal Wastewater for Increasing the Sludge Dewatering Efficiency

Municipal wastewater sludge was produced by chemical coagulation of synthetic wastewater (sww) based on Synthene Scarlet P3GL disperse dye and real municipal wastewater (nww), coagulated by commercial coagulants PAX (prepolymerised aluminum coagulant) and PIX (a ferric coagulant based on Fe2(SO4)3). An attempt was made to correlate the sludge’s dewatering capacity (in terms of capillary suction time—CST) with operation parameters for wastewater treatment, size distribution and specific surface area of the sludge particles. It was found that the presence of phosphate ions in the system facilitates the removal efficiency of the above-mentioned dye (L) due to the interaction between the dye molecules and H2PO4− ions. Unlike sww, negatively charged organic substances (sorg) in nww are directly adsorbed on the surface of colloidal particles {Fe(OH)3} and {Al(OH)3} (prtc). It was also discovered that an increase in the dose of a coagulant led to an increase of CST for sww sludge and to a decrease of CST for nww sludge. It has been suggested that flocs composed of spherical {Al(OH)3} units possessed more internal space for water than aggregates consisting of rod-shaped {Fe(OH)3} units and, consequently, it is more difficult to remove water from Al-sww sludge than from Fe-sww. The results obtained showed that smaller particles dominate in sww sludge, while larger particles are prevalent in nww sludge. To explain this distinct difference in the size distribution of particles in sludge obtained with the use of Al3+ and Fe3+, simple models of aggregation and agglomeration-flocculation processes (aaf) of treated wastewater have been proposed. Except for PIX in nww, the analyzed particles of the investigated types of sludge were characterized by similar specific surface area (Sps), regardless of the kind of sludge or the applied coagulant. Slightly larger, negatively-charged sorg bridges, anchored directly on the surface of positive prtc are more effective in closing the structure of nww sludge than small L bridges of the dye molecules anchored on the surface of prtc via H2PO4−. All the discovered aspects could lead to improved performance of wastewater treatment plants (WWTP) by increasing the efficiency of sludge dewatering.

Valorisation of a wastewater in the treatment of leachate from municipal solid waste in Morocco

In most countries, sanitary landfilling is the common way to dispose municipal solid wastes. In general, leachate treatment is a difficult and expensive process. Although; leachate can be treated by biological processes, chemical oxygen demand removal efficiency is usually low due to high ammonium ion content and the presence of toxic compounds such as metal ions. This experimental study was conducted to investigate the effect of coagulation-flocculation process on the fresh leachate resulting from compacting of solid waste of Mohammedia city. The effects of steel industry wastewater (SIWW) rich in Fe3+ and commercial coagulant ferric chloride of 40% with various dosages and also coagulation pH on the removal of turbidity, colour, chemical oxygen demand (COD), biological oxygen demand (BOD5) and total suspended solids were studied. Based on the results of this study, the best coagulant for colour and turbidity removal was SIWW. An equivalent of 7,080 mg.L−1 of FeCl3 was needed to effectively remove 63% of turbidity. This liquid waste can remove 44.5% of COD at the concentration equal to 1,000 mg.L−1 of FeCl3. The physico-chemical process may be used as an effective pre-treatment process, especially for fresh leachate, prior to post-treatment (polishing) for partially stabilised leachate.

Valorisation of a wastewater in the treatment of leachate from municipal solid waste in Morocco

In most countries, sanitary landfilling is the common way to dispose municipal solid wastes. In general, leachate treatment is a difficult and expensive process. Although; leachate can be treated by biological processes, chemical oxygen demand removal efficiency is usually low due to high ammonium ion content and the presence of toxic compounds such as metal ions. This experimental study was conducted to investigate the effect of coagulation-flocculation process on the fresh leachate resulting from compacting of solid waste of Mohammedia city. The effects of steel industry wastewater (SIWW) rich in Fe3+ and commercial coagulant ferric chloride of 40% with various dosages and also coagulation pH on the removal of turbidity, colour, chemical oxygen demand (COD), biological oxygen demand (BOD5) and total suspended solids were studied. Based on the results of this study, the best coagulant for colour and turbidity removal was SIWW. An equivalent of 7,080 mg.L−1 of FeCl3 was needed to effectively remove 63% of turbidity. This liquid waste can remove 44.5% of COD at the concentration equal to 1,000 mg.L−1 of FeCl3. The physico-chemical process may be used as an effective pre-treatment process, especially for fresh leachate, prior to post-treatment (polishing) for partially stabilised leachate.

REUSE OF LEATHER WASTE: COLLAGEN HYDROLYZATE FOR THE TREATMENT OF TANNERIES EFFLUENTS

The tannery industry is an important economic activity in Argentina. Due to the characteristics of their processes, tanneries generate liquid effluents in different acidity or alkalinity conditions, with high turbidity, suspended solids and color. These effluents must be treated to avoid environmental contamination. The objective of the present investigation was to study, at a laboratory scale, coagulation processes that allow the reduction of turbidity and color in tannery effluents. The work focused on the use of collagen hydrolyzate (CH) as a coagulant, obtained from the shavings that the leather process itself discards. Tests were made with pure CH, in combination with a commercial coagulant (aluminum sulfate) or a commercial flocculant (cationic quaternary polyamine), in order to compare the efficiency of the process. Effluents were generated with a generic tanning formula, which were treated by aeration followed by sedimentation. The results obtained show that the CH alone does not show sufficient effectiveness, but combined with both the aluminum sulphate and the cationic quaternary polyamine gives very good results, involving smaller amounts of these commercial additives. The fact that the CH is obtained from a residue of the industry itself and it can successfully replace other chemicals, lowers the costs of treating the liquid effluents while avoiding having to manage that solid waste.

Fluorides decontamination by means of Aluminum polychloride based commercial coagulant

The fluoride removal efficiency of the commercial product Actifluo (Brenntag) has been evaluated on both real industrial wastewater samples as well as on synthetic wastewaters. This study demonstrates that the treatment with the Aluminum polychloride (PAC) containing Actifluo, after a preliminary precipitation step with Ca(OH)2, improved the efficiency in the fluoride removal. This has been proved on wastewaters coming from four different companies of the south of Italy. In all the cases, the Actifluo treatment led to residual fluorides falling within the Italian law limits (fixed at 12 mg/L for sewage and 6 mg/L for surface waters). As a matter of fact, independently of the initial fluoride concentration, final values lower than 3 mg/L were obtained by treating wastewaters coming either from glass or dye factories.To determine whether pH and particle surface influenced the decontamination efficiency in surface water, synthetic wastewaters were analyzed by means of ζ-potential and Dynamic light scattering. The close relationship between pH and surface charge of the coagulant polymer present in the Actifluo was established and their effects on the fluoride removal efficiency assessed.

Comparative study on the effectiveness of natural coagulant aids and commercial coagulant: removal of arsenic from water

A novel cellulose and chitosan-based natural biopolymer or coagulant aids with a commercial coagulant (ferric chloride FeCl3) have been used for the removal of arsenite As(III) from synthetic tap water at 2 mg/L of initial arsenic concentration by coagulation–flocculation method. The maximum As(III) removal efficiency of 69.25% was obtained without coagulant aids at 40 mg/L concentration of FeCl3. The addition of cellulose and chitosan with FeCl3 enhanced the removal efficiency of As(III). The percentage of As(III) removal reached 84.62 and 74.87% at the concentration of 1 and 1.5 mg/L for cellulose and chitosan, respectively, with 25 mg/L of fixed FeCl3 concentration. Comparable As(III) removal efficiencies were obtained using cellulose, chitosan, and FeCl3. Moreover, As(III) removal efficiency of cellulose was significantly found greater (p < 0.01) than chitosan and comparable to that of FeCl3 (p < 0.01). In addition, the maximum percentage of As(III) removal was found at the pH range of 6–8.

Phosphorus removal by application of natural and semi-natural materials for possible recovery according to assumptions of circular economy and closed circuit of P

In the last few years the idea of circular economy has become essential. Thus, designing methods of nutrients removal should be based on using materials that make it possible to recover those nutrients. Recently, methods applied in wastewater treatment plants cannot provide optimal results; moreover, the application of commercial coagulants like ferric chloride and polyaluminum chloride can cause difficulties in potential recovery of phosphorus from sludge. Sorption materials, both natural and modified, are appearing as successful for wastewater treatment, especially for treatment wetland effluent. To pursue circular economy principles, the capacity of waste materials needs to be tested with regard to nutrients removal. If in addition a possibility to recover them appears, it will be possible to close the circuit. The aim of the investigation, according to HELCOM and EU Water Framework Directive recommendations, was to explore the possibility of ensuring good and stable quality of effluent by the application of natural materials for phosphorous removal with possible minimum energy and material consumption. The objective was to determine the sorption capacity of two selected materials (waste material and chemically modified material) in steady conditions. The research focused also on the time of mixing, a period of sedimentation of absorbent materials, and the influence of used materials on the basic parameters of the solution: pH, temperature, total suspended solids, conductivity, turbidity, and color. M1 was a waste material after thermal treatment of carbonate-siliceous rock in temperature above 700 °C (Rockfos®). Material M2 was lanthanum-modified bentonite, a material of anthropogenic origin. Both selected materials have shown a high ability to reduce phosphates concentration in synthetic wastewater. Sorption capacity of materials M1 and M2 were 45.6 mg/g and 5.6 mg/g, respectively.

Milk-clotting activity of high pressure processed coagulants: Evaluation at different pH and temperatures and pH influence on the stability

Abstract This study evaluated the milk-clotting activity (MCA) at different pH values and temperatures of milk and the influence of pH on the stability of commercial coagulants subjected to high pressure processing (HPP). The pressurized enzymes showed higher MCA for almost all conditions studied, as compared to the non-processed samples, and the differences were more pronounced at higher temperatures and lower pH values. For the conditions used in industrial cheese making (pH 6.6 at 35 °C), the HPP led to an increase in MCA of 27, 9, 8, and 5% for the recombinant camel chymosin, bovine rennet, calf rennet, and porcine pepsin, respectively. In addition, HPP increased the pH stability for most of the enzymes. Therefore, HPP emerges as an effective technology to improve the hydrolytic profile of these enzymes as a function of pH and temperature. Industrial relevance HPP was able to promote increased in milk-clotting activity and stability of coagulants at different temperatures and pH values. For some enzymes the pressurization increased the activity at a natural pH of the milk (pH 6.6), resulting in activity similar to that observed for native enzyme at lower pH and higher temperatures. Thus, such conditions lead the use of less enzyme concentration in coagulation process, reducing costs. Additionally, it was also shown that lyophilization preserved the changes induced by the HPP in enzymes solution. Therefore, HPP technology is a unit operation can be used to increase activity and stability of milk-clotting enzymes.

Studies on the treatment of surface water using rajma seeds

Abstract Indiscriminate disposal of wastewater with suspended solids have led to higher amount of pollution to the natural water bodies. Turbidity removal becomes an essential part in the water treatment when surface water is used for drinking purpose, this can be achieved by means of coagulation process. Coagulation process is the dosing of a coagulant in water, resulting in the destabilization of negatively charged particles. Commercial coagulants which were widely used can synthesize by-products in turn may pollute the environment and deteriorate the ecosystem at a slow rate. So, now-a-days natural coagulants are used as a potential substitute because it’s biodegradable, ecofriendly and non-toxic. In this study, the turbid surface water samples were treated using powdered seeds of Rajma (natural coagulant) followed by variations in dosage, settling time and pH were also studied. From the results obtained, it was found that the Rajma seeds powder achieved 48.80% efficiency for 0.5 g/l of optimum dose at pH 6 for 20 min settling time respectively.

Use of different coagulants for cassava processing wastewater treatment

The processes necessary for transformation of cassava into starch generate several residues, among them cassava wastewater (manipueira) that has high pollutant load. For the effluent treatment system it is essential to remove sedimented suspended solids, which can be performed by the coagulation/flocculation/sedimentation process (C/F/S), requiring a comparative study between coagulants for the successful selection of the coagulant and its dosage. Therefore, the aim of this work was to investigate the efficiency of different coagulants in color and turbidity removal of starch industry effluent. In this way, jar-test experiments were conducted. Four natural commercial coagulants (Acquapol WW, Acquapol S5T, Tanfloc SL, Tanfloc SG) and a chemical coagulant (Al2SO4) were tested at concentrations of 160, 320, 480, 640 and 800 mg L−1, setting the fast mixing stage for 2 min at 120 rpm and the slow mixing stage for 15 min at 20 rpm, at natural pH of the effluent. Among the studied coagulants, natural commercial coagulants presented greater efficiency of color and turbidity removal when compared to chemical coagulant, besides having the advantage of being non-toxic and from renewable source. All coagulants had a minimum sedimentation time of 15 min. The best natural coagulant (Acquapol S5T and Tanfloc SL) concentration determined from statistical analysis (ANOVA, p-value <0.05; Turkey’s test, p-value >0.05) was 320 mg L−1, capable in removing color (≥77.5%) and turbidity (≥88.5%) parameters for treatment of the studied effluent. The C/F/S process employing these two selected coagulants proves to be an effective physico-chemical method for primary treatment of this type of effluent, contributing to the improvement in wastewater quality.

Performance of aluminium formate in removal of colloidal latex particles from industrial wastewater

The coagulation efficiency of novel coagulant aluminium formate was studied in the treatment of highly contaminated effluent from a styrene butadiene latex manufacturing plant. The coagulation behaviour of the aluminium formate was compared to the behaviour of the commonly used polyaluminium chloride and aluminium sulphate. The effects of the coagulant type and dose and coagulation pH on the treatment efficiency were studied as well as the role of polyacrylamide coagulant aid. Floc separation was done using three different methods sedimentation, filtration and centrifugation. Their functionality was evaluated as part of the coagulation performance studies. Good purification results were obtained with all of the tested coagulants, the lowest residual turbidities achieved being 0.7 NTU with aluminium formate, 1.4 NTU with polyaluminium chloride and 0.7 NTU with aluminium sulphate. It was also observed that aluminium formate is as effective as commercial coagulants and is thus a potential novel coagulant chemical due to its less harmful and biodegradable counter anion. When using only aluminium coagulants, flocs were found to be too fine to be removed by sedimentation but they could be effectively removed by filtration or centrifugation. The use of polyacrylamide was found to be useful in the sense that it enables the separation of flocs by simple sedimentation because the floc size is significantly increased. In this study new knowledge about the coagulation behaviour of highly contaminated effluent from latex manufacturing was gained and aluminium formate was proved to be promising coagulant also in industrial effluent treatment.

Utilization of Drinking Water Treatment Slurry to Produce Aluminum Sulfate Coagulant.

In Egypt, water treatment consumes about 365 000 tons of aluminum sulfate and produces more than 100 million tons of sludge per year. The common disposal system of sludge in Egypt is to discharge it into natural waterways. Toxicity of aluminum, environmental regulations and costs of chemicals used in water treatment and sludge treatment processes led to an evaluation of coagulant recovery and subsequent reuse. The present work aimed at aluminum recovery from sludge of El-Shiekh Zayd water treatment plant (WTP) to produce aluminum sulfate coagulant. Sludge was characterized and the effect of five variables was tested and the process efficiency was evaluated at different operating conditions. Maximum recovery is 94.2% at acid concentration 1.5 N, sludge weight 5 g, mixing speed 60 rpm, temperature 60 °C and leaching time 40 min. Then optimum conditions were applied to get maximum recovery for aluminum sulfate and compared to commercial coagulant on raw water of El-Shiekh Zayd (WTP).

Influence of vegetable coagulant and ripening time on the lipolytic and sensory profile of cheeses made with raw goat milk from Canary breeds.

Free fatty acids and sensory profiles were obtained for cheeses made with raw goat milk and vegetable coagulant, derived from the cardoon flower ( Cynara cardunculus), at different ripening times (7 and 20 days). A solid-liquid phase extraction method followed by solid-phase extraction and gas chromatography was used. Profiles were also obtained with cheeses made with commercial coagulant, traditional kid rennet paste, and mixture coagulant (vegetable coagulant-kid rennet). The use of vegetable coagulant and vegetable coagulant-kid rennet is common in traditional Protected Designation of Origin cheeses such as " Queso Flor de Guía" and " Queso Media Flor de Guía" (Spain). Contents of short-chain free fatty acids (7.5-22.5 mmol·kg-1), medium-chain free fatty acids (0.4-3.7 mmol·kg-1), and long-chain free fatty acids (0.2-2.1 mmol·kg-1) varied depending on the coagulant type and the ripening time. Vegetable coagulant cheeses present odour intensity and flavour intensity much higher than commercial coagulant cheeses in the sensory analysis for cheeses obtained with seven days of ripening, but the values decrease when increasing the ripening time. Multivariate analysis allowed us to differentiate cheese samples according to the ripening time when using lipolytic profile and according to the coagulant type using the sensory profile.

Cationic nanocelluloses in dewatering of municipal activated sludge

This study used cationic nanocelluloses (CNFC I and II) produced by nanofibrillizing periodate oxidized and aminoguanidine hydrochloride reacted wood cellulose as flocculation agents for municipal activated sludge. For both CNFC I and II, the diameters ranged from about 2–8nm. Lengths ranged from hundreds of nanometers for CNFC I and about 50–100nm for CNFC II. The charge densities for CNFC I and II were 1.07 and 1.70meqg−1, respectively. The study examined the flocculation performance of the two CNFCs in the conditioning treatment of municipal activated sludge and compared the results with the performance of both a commercial coagulant and polyelectrolyte (polyacrylamide). Results showed that both CNFC I and II were able to flocculate activated sludge efficiently at effective doses similar to those of the commercial cationic polymer and at doses lower than the reference coagulant. Their efficiency in reducing turbidity was nearly as good as that of the synthetic reference polymer, and their COD was even better than that of the synthetic reference polymer. The performance of CNFC II was slightly better than that of CNFC I. In centrifugation analyses, the use of both CNFCs resulted in dense sludge cakes with moderate swelling and good colloidal-removal efficiency.

Comprehensive reuse of drinking water treatment residuals in coagulation and adsorption processes

While drinking water treatment residuals (DWTRs) inevitably lead to serious problems due to their huge amount of generation and limitation of landfill sites, their unique properties of containing Al or Fe contents make it possible to reuse them as a beneficial material for coagulant recovery and adsorbent. Hence, in the present study, to comprehensively handle and recycle DWTRs, coagulant recovery from DWTRs and reuse of coagulant recovered residuals (CRs) were investigated. In the first step, coagulant recovery from DWTRs was conducted using response surface methodology (RSM) for statistical optimization of independent variables (pH, solid content, and reaction time) on response variable (Al recovery). As a result, a highly acceptable Al recovery of 97.5 ± 0.4% was recorded, which corresponds to 99.5% of the predicted Al recovery. Comparison study of recovered and commercial coagulant from textile wastewater treatment indicated that recovered coagulant has reasonable potential for use in wastewater treatment, in which the performance efficiencies were 68.5 ± 2.1% COD, 97.2 ± 1.9% turbidity, and 64.3 ± 1.0% color removals at 50 mg Al/L. Subsequently, in a similar manner, RSM was also applied to optimize coagulation conditions (Al dosage, initial pH, and reaction time) for the maximization of real cotton textile wastewater treatment in terms of COD, turbidity, and color removal. Overall performance revealed that the initial pH had a remarkable effect on the removal performance compared to the effects of other independent variables. This is mainly due to the transformation of metal species form with increasing or decreasing pH conditions. Finally, a feasibility test of CRs as adsorbent for phosphate adsorption from aqueous solution was conducted. Adsorption equilibrium of phosphate at different temperatures (10–30 °C) and initial levels of pH (3–11) indicated that the main mechanisms of phosphate adsorption onto CRs are endothermic and chemical precipitation; the surfaces are energetically heterogeneous for adsorbing phosphate.

Novel milk-clotting enzyme from Bacillus stearothermophilus as a coagulant in UF-white soft cheese

The Crude enzymatic extract produced by Bacillus stearothermophilus exhibited high milk-clotting activity (MCA). Optimized medium and conditions increased the enzyme production to 189.68%. Moreover, dissolving skim milk in acetate buffer and in acetate buffer containing CaCl2 increased the activity to 353.01% and 394.01%, respectively. MCA was increased to 462.76% when assayed at higher temperature (60 °C). Mn+2 and Ca+2 ions stimulated MCA to 642.11% and 134.92%, respectively. In the presence of 0.1 M NaCl the activity was increased to 128.34%, however, at 0.8 M the activity was decreased to 38.40%. MCE showed excellent thermal and pH stability by retaining all of its activity after incubation at 40 °C for 60 min and at pH 4.0 for 90 min. Furthermore, milk-clotting enzyme (MCE) retained its complete activity when stored at −18 °C and 4 °C for 40 and 30 day, respectively. UF-white soft cheese chemical characteristics were similar of both B. stearothermophilus MCE and other commercial coagulants. Moreover, cohesiveness, springiness, gumminess and chewiness were similar of cheese made with all tested coagulants. The flavor of B. stearothermophilus cheese was similar with other commercial coagulants during all storage period. Also, the total score of organoleptic properties of cheeses made by B. stearothermophilus coagulant were lower than other commercial coagulants during all storage period. Thus this novel coagulant (26 ml/l milk) could be used to produce acceptable UF-white soft cheese.

Evaluating magnetic nano-ferrofluid as a novel coagulant for surface water treatment

In the area of environmental remediation, nanomaterials offer the potential for the efficient removal of pollutants and biological contaminants. With the rapid development of nanotechnology, nano-ferrofluid or magnetic fluids are currently being widely studied in water treatment field. The utilization of iron oxide nanomaterials or magnetic nanoparticles (MNs) has received great attention due to their unique properties, such as biocompatibility, small size, high surface area to volume ratio, and easy separation from solution using an external magnetic field. However, a few works have been conducted on coagulant and enhancing coagulation process using simple nano-ferrofluid without any modification. In the present study, at first, we synthesized nano-ferrofluid; then, after characterizations, we use the magnetic fluid for water treatment. For this purpose, we choose Karun River in the southwest of Iran as a model and water samples are collected. Then, they are treated with a small amount of magnetic fluid. In this process, the effect of this nanomaterial on turbidity, hardness, alkalinity, removal of some important heavy metal cations, and important anions like phosphate, population of coliform bacteria and fecal coliform bacteria, and amount of chemical oxygen demand (COD) is investigated separately. Also, the effect of some important parameters such as time and rate of mixing steps, pH, temperature, and reusability of these nanomagnetic particles as a coagulant is investigated and the interesting and applicable results are obtained. In general, the combination of removing important hazardous ions with 1μgmL−1 such as Cd2+, Co2+, Mn2+, Fe2+, Pb2+, Zn2+, Ni2+, and Cu2+ cations (more than 90%), great ability in decreasing turbidity (about 90%), excellent antibacterial efficiency (98% of fecal coliform bacteria and 97% of coliform bacteria were removed), decreasing COD (about 60%), green and cheap preparation, ease of use, and decreased time of separating those with external magnetic field compared to available commercial coagulants. To the best of our knowledge, most of available coagulants can only decrease turbidity. Notably, in decreasing turbidity, MNs have the same efficiency over the pH range (4.0–8.0) and temperature range (15–45°C) in real samples. Meanwhile the most coagulants do not have these properties simultaneously.

Effect of crude and defatted Moringa oliefera seeds as natural coagulants in the removal of physical, chemical and bacteriological parameters from turbid river water

There is a great concern about commercial coagulants and their residues in treated water which leads to Alzheimer disease in old people. For this reason, a lot of research is focused on plants with coagulating properties. A lot of interest is on Moringa oliefera as a plant with clarifying properties, this study was aimed at investigating efficiency of crude and defatted Moringa oliefera seed in aiding removal of turbidity, chemical and bacteriological parameters from turbid Ndarugo river water in comparison with alum. Conventional jar test apparatus was used in coagulation process. The optimum dosages was obtained at 50 mg/L, 175 mg/L and 150 mg/L which gave represented residual turbidity of 3.73±0.09, 4.93±0.31 and 3.27±0.45 for alum, crude Moringa oliefera seed powder and defatted Moringa oliefera seed powder respectively. Total coliforms were reduced to between 93.48% to 96.96% by all the coagulants; however E. coli was not detected in raw turbid water and clarified sample. In the study, it was observed that Moringa oliefera seed showed a good alternative as coagulants reducing water parameters to values below maximum permissible limits as stipulated by WHO.

Coalho Cheese Made with Protease from Thermomucor indicae-seudaticae N31: Technological Potential of the New Coagulant for the Production of High-Cooked Cheese.

The aim of this study was to explore the use of a new coagulant from Thermomucor indicae-seudaticae N31 for the manufacture of a high-cooked starter-free cheese variety, by evaluating its physicochemical and functional characteristics in comparison to cheeses made with a traditional commercial coagulant. Coalho cheese was successfully produced with the new protease as it exhibited comparable characteristics to the one produced using the commercial enzyme: pH behavior during manufacture; cheese composition; protein and fat recovery; and cheese yield. In addition, during storage, melting was low and not affected by storage time; the increase of TCA 12% soluble nitrogen (% of total nitrogen) was lower than half of that of pH 4.6 soluble nitrogen (% of total nitrogen); concentration of β-CN significantly decreased, whereas αs1 -CN concentration was not affected by storage time.