Alum Coagulation Research Articles

The Changing of Dissolved Organic Matter Based on Its Molecular Weight Through Alum Coagulation and Adsorption Activated Carbon

Surface water may contain dissolved organic matter (DOM), which is derived from microbial activities in water and discharged from the watershed. Source water is mainly used as raw water for clean and drinking water, and DOM in water could affect the treated water quality. Therefore, it is necessary to remove DOM in water. This study aims to know the efficiency of removal of DOM by using alum coagulation followed by adsorption with activated carbon. In addition, this study applied the chromatograms method to identify the changing of DOM based on its molecular weight. The results show that raw water was composed of two main organic fractions: humic substances and low molecular weight acids and neutral.The humic substances organic fractions have been removed through alum coagulation up to 48%, and removal increased up to 85% through adsorption with activated carbon. The low molecular weight acids and neutral organic compounds have been removed about 85% and 40% in alum coagulation and adsorption,respectively.

Alum, Chitin and Sago as coagulants for the optimization of process parameters focussing on coagulant dose and mixing speed

Water demand for consumption has been increasing continuously due to the expanding population worldwide. The current accessible water is continually contaminated by global climate change and anthropogenic activities. Economically viable and safe treatment technologies are required for the contemporary world to meet the water demand. The coagulation process is an economically feasible method and gaining much prominence in developing countries for water treatment. During the operation, Sludge and secondary by-products are formed due to the overdosage of the coagulant and improper mixing speeds. Optimizing process parameters is essential to reduce the costs associated with further treatment. Thus, the current study aimed to optimize the process parameters by using Alum, Chitin and Sago coagulants with three pH variations, i.e., 6, 7, and 8, with a mixing speed of 100-30 and 80-20 rpm. The results revealed that Sago performed better than other coagulants and removed the turbidity up to 99.42 %. In addition, Sludge was reduced to 90% with a dosage of 0.4 g/L, a minor dosage compared to the literature with an optimal pH of 7. Further, the coagulants were characterized to identify the functionalized groups by FTIR, the nature of the coagulant by XRD and Surface morphology by SEM. From the current study, it can be concluded that a coagulant dose ranging from 0.1 to 0.4 g/L with a mixing speed of 100 rpm for 2 minutes and 30 rpm for 30 minutes might be the best solution for obtaining greater coagulation efficiency.

Comparison of natural extract as a clean coagulant with alum and natural extract-alum hybrid coagulant for removal of water turbidity

Comparison of natural extract as a clean coagulant with alum and natural extract-alum hybrid coagulant for removal of water turbidity

Modeling Jar Test Results Using Gene Expression to Determine the Optimal Alum Dose in Drinking Water Treatment Plants

Coagulation is the most important process in drinking water treatment. Alum coagulant increases the aluminum residuals, which have been linked in many studies to Alzheimer's disease. Therefore, it is very important to use it with the very optimal dose. In this paper, four sets of experiments were done to determine the relationship between raw water characteristics: turbidity, pH, alkalinity, temperature, and optimum doses of alum [ .14 O] to form a mathematical equation that could replace the need for jar test experiments. The experiments were performed under different conditions and under different seasonal circumstances. The optimal dose in every set was determined, and used to build a gene expression model (GEP). The models were constructed using data of the jar test experiments: turbidity, pH, alkalinity, and temperature, to predict the coagulant dose. The best GEP model gave very good results with a correlation coefficient (0.91) and a root mean square error of 1.8. Multi linear regression was used to be compared with the GEP results; it could not give good results due to the complex nonlinear relation of the process. Another round of experiments was done with high initial turbidity like the values that comes to the plant during floods and heavy rain. To give an equation for these extreme values, with studying the use of starch as a coagulant aid, the best GEP gave good results with a correlation coefficient of 0.92 and RMSE 5.1

Pengolahan Limbah Cair Batik Banten secara Koagulasi Menggunakan Tawas dan Adsorpsi dengan Memanfaatkan Zeolit Alam Bayah

The batik industry produces liquid waste from the coloring, washing and rinsing processes. This study was aimed to analyze the quality of Banten batik effluent before and after treatment. The processing is carried out using an experimental method with a batch system by coagulation using alum and adsorption using Bayah's natural zeolite by performing 3 variations of coagulant mass and adsorbent for the dye test parameters, TDS and TSS. The results of the test before treatment were the results for dyes of 344 TCU, TDS 620 mg/L, and TSS 218.5 mg/L. Based on the coagulation treatment using alum, the most efficient coagulant results were obtained to reduce the levels of dyestuffs and TDS, namely by using alum coagulant as much as 1500 mg/L which resulted in 96.6 TCU and 330.0 mg/L respectively, then to reduce TSS levels obtained an efficient coagulant that is 500 mg/L with a yield of 10 mg/L. The adsorption treatment using Bayah natural zeolite can reduce the levels of TDS and TSS with the most efficient results using an adsorbent of 150 g/L obtained for TDS 189.3 mg/L and TSS 13.3 mg/L. So based on the results of processing using coagulation and adsorption methods, it is hoped that the batik industry can apply it in processing the liquid waste produced.

Liquid smoke application in latex as an environment-friendly natural coagulant

Liquid smoke has many benefits, especially in the food, fishery, timber, and plantation industries. It is used as a preservative or durability increased and aroma and taste addition in the food and fishery industry. In the wood industry, liquid smoke can resist termite attacks, while in the plantation industry, it functions as a latex coagulant containing antifungal, antibacterial, and antioxidants that can improve rubber product’s quality. Most of the rubber farmers in Bangka Belitung still use alum as a coagulant to coagulate their latex. However, alum coagulant can reduce the quality of the processed rubber material (bokar). The reason farmers use alum is that raw materials are cheap, therefore getting coagulant raw materials at low prices and not pollute the environment with a less moderate aroma/odor caused by non-recommended coagulant materials (alum) are needed. This study aims to apply liquid smoke as a natural coagulant in latex freezing. The research method used a Completely Randomized Design, with liquid smoke concentration replicated three times. Parameters observed were clotting time speed and organoleptic test for odor during 14 days of storage. The results showed that the best concentration of liquid smoke was 15% no odor and a clotting time of 8.23 minutes.

Effective Treatment of Chocolate Industry Effluent Using Waste from Biocosmetic Industry

AbstractThe revaluation of industrial wastes has great environmental benefits. Bio‐cosmetic industry has known huge success worldwide and eventually large amounts of wastes are produced. A bio‐cosmetic industrial waste (BCIW) was experimentally evaluated for its efficiency compared to Moringaoleifera seeds powder (MOSP) and aluminum sulfate (alum) coagulants to treat chocolate industry wastewater (CIWW). Confectionery industrial wastewater is commonly defined by high turbidity, chemical oxygen demand (COD), total solids, total volatile solids, and carbohydrates that may cause detrimental environmental pollution if discharged directly. M.oleifera seeds are largely studied by several researchers and alum is widely used in the industrial wastewater treatment due to its performance and low price. However, industrial bio‐cosmetic waste has never been used as a coagulant in previous studies. In this study, the removal of turbidity and COD from CIWW is investigated in relation to coagulant concentration and coagulation pH. It is found that the industrial waste performs better than MOSP and alum in removing turbidity and COD. The results show that BCIW removes more than 99% turbidity and over 87% COD at optimal treatment conditions of coagulant concentration and pH. The findings suggest that the BCIW has the potential to be utilized as a bio‐coagulant for treating CIWW.

Image Analysis for Spectroscopic Elemental Dot Maps: P, Al, and Ca Associations in Water Treatment Residuals as a Case Study

The associations of elements upon a heterogeneous surface may control nutrients or pollutants sorption and release, having agricultural and environmental implications. This chemical behavior can be elucidated by spatial spectroscopy, followed by image analysis. The purpose of this paper is to present a working procedure for image analysis using the free program ImageJ that can be applied for dot maps of three or more elements produced by solid-state spectroscopy. Detailed step-by-step instructions lead to visual and quantitative information regarding elements associations. The working procedure was demonstrated for P, Al and Ca dot maps produced by scanning electron microscopy energy dispersive spectroscopy (SEM-EDS) for surfaces of Al-based water treatment residuals (Al-WTRs), a by-product of drinking water pretreatment with alum coagulant. Al-WTR was reused to adsorb the macro-nutrient P from polluted soil leach and dairy wastewater (WW). Surficial P onto Al-WTR, SL-Al/O-WTR, and WW-Al/O-WTR (0.56, 0.93, and 2.15%, respectively) displayed sorption dynamics, mostly with Al and Ca. Quantification of the spatial proportions of individual elements and their associations indicated P-Al pool > P-Ca pool (45–24% and 17–7%, respectively). Upon introducing P-rich dairy wastewater, the behavior of P sorption by Al and Ca changed and became more clustered. A ternary phase of P-Al-Ca covered 38% of the area with signal, compared to 4.3 and 4.6% of the area in Al-WTR and SL-Al-WTR, where it was limited to particles edges only. Thus, the presented protocol may promote employing image analysis for geochemical applications, elucidating chemical behavior and affinities. Advantages and pitfalls are discussed.

Optimization of process parameters in coagulation of landfill leachate by Al2(SO4)3 and PACl

In this study, landfill leachate treatment by coagulation and optimization of process parameters were aimed. Alum (Al2(SO4)3) and Poly Aluminum Chloride (PACl) were used as coagulants to remove total suspended solids (TSS) from landfill leachate, and coagulant dose, reaction time, and pH were optimized as process variables. The Box-Behnken, one of the response surface methodology designs, was used in modeling the coagulation process. The R2 values were very high (>95%) for TSS removal and the models were sufficiently in good agreement with experimental results. The TSS removal efficiencies in coagulation processes with alum and PACl under optimum process conditions determined by the model were 62.1% and 76.4%, respectively while the experimental values under optimum operating conditions were 60.8% and 75.1% in alum and PACl coagulation processes, respectively. According to the results of the study, both coagulation processes were effective in TSS removal from landfill leachate, and response surface methodology is a useful tool for optimizing the treatment parameters. The removal efficiency of the coagulation process conducted with PACl is higher than that of the alum process. Thus, it can be inferred that PACl is more effective under optimized conditions in this study.

Potential of Strychnos Potatorum and Eirchorrnia Crassipes in Treating Dyeing Industry Waste

The research aim is to the treatment of industrial dyeing waste water for the analysis of improved water treatment using natural coagulants. For waste water treatment, natural coagulants such as Strychnos potatorum (nirmali seeds) and Eirchorrnia crassipes (water hyacinth) are used. We have test the various properties of dyeing waste water before and after treatment like pH, sulphates, chlorides, total solids, total suspended solids (TSS), total dissolved solids (TDS), acidity, alkalinity, optimum coagulant dosage (jar apparatus), biological oxygen demand (BOD) and chemical oxygen demand (COD) .The test results showed that natural coagulants produce better results when used alone or in conjunction with the chemical coagulant alum. Since the natural coagulant generates less floc, the cost of sludge treatment is reduced. Water hyacinth outperforms nirmali seed in terms of natural coagulants. Natural coagulants may be used to manage and treat the dyeing waste water, anywhere there is an abundance of it.

Production and quality evaluation of soy cheese (tofu) using various coagulants

Food formulations that incorporate soy ingredients are being exploited as veritable alternatives. Cheese analogues are healthy alternatives to obtain the benefits of consuming functional foods. There is a need to enhance the production and quality of soy cheese. In this study, soy cheese (tofu) samples were prepared from soybean using four selected coagulants - Moringa oleifera seed extract (MC), tamarind seed extract (TC), lime juice (LC) and alum (AC). The effects of the coagulants on the physicochemical, microbial and sensory qualities of the soy cheese samples were evaluated. The results of the physical properties of the samples showed that MC had higher yield (12.84%) and acidity (0.37%), while AC had the highest values in hardness (84.55%) and dry matter (36.72%) content. The result of the proximate composition revealed that MC had the lowest moisture content (60.52 %) and the highest protein content (22.51%). The ash content of the soy cheese samples from plant coagulants MC (3.00%), TC (2.80%) and LC (3.5%) were lower than that of the alum coagulant AC (3.89%). The cheese from alum coagulant (AC) had more minerals than those from plant coagulants. TC had the highest vitamin C (2.69 mg/100 g), while MC had the highest vitamin B1 (6.07 mg/100 g) and B2 (29.21 mg/100 g) contents. There was no detection of coliform in the soy cheese samples. There were no significant differences (p>0.05) in the appearance and overall acceptability of MC sample and LC sample MC sample from Moringa oleifera seed extract coagulant had the highest sensory scores for flavour (8.35), texture (8.40) and overall acceptability (8.63). The results of quality properties of the cheese samples differed with the coagulants used. Moringa Oleifera coagulated cheese (MC) had superiority in nutrients and sensory qualities Hence, it is recommended for tofu production.

Using electro- and alum coagulation technologies for treatment of wastewater from fruit juice industry in New Damietta City, Egypt.

Electrocoagulation technology is being increasingly used to treat various types of wastewater over the last several years. This study aimed to investigate the industrial wastewater treatment of a fruit juice factory as an example of food processing industries in New Damietta City, Egypt, by using electrocoagulation technology. This is to solve an environmental problem, represented in the high organic load of these effluents. The electrocoagulation treatment processes were examined by using two electrodes of aluminum (Al) and two electrodes of stainless-steel (SS) and also by using Al as an anode and SS as a cathode. In addition, treatment by alum coagulation was investigated. Results showed that electrocoagulation was more effective than alum coagulation. The use of two combined electrodes of Al as an anode and SS as a cathode resulted in an 83.78% COD removal efficiency, while the use of the alum coagulant yielded 57.57%. Furthermore, total operating cost was calculated, and the amount of hydrogen gas as a subsequent energy alternative was theoretically determined in order to solve the process' power problem.

Cement kiln dust as an alternative technique for wastewater treatment

This study was conducted to examine cement kiln dust (CKD) efficiency for wastewater treatment. We analyzed the physicochemical characteristics of wastewater before and after treatment and then we determined its removal potential. The optimum factors of the treatment process were determined using a jar test technique. It was pH (8.1), dosage (1.9 g) and grain size (0.1 mm) with contact time of 30 min at 150 rpm. CKD pollutant removal efficiency reached 85.3, 81.6, 97.1, 86.8, 36, 74, 61.2, and 94.6% for BOD, COD, TP, TN, TDS, salinity, conductivity and turbidity, respectively, with an increase in the concentration of DO of 84%. On the other hand, removal percent of heavy metals achieved were 88.4, 90.9, 88.5, 97.2, 94.2, 70, and 79.9% for Pb, Cd, Zn, Fe, Co, Ni, and Cu, respectively. These results were compared with alum removal potential of wastewater treatment for confirmation. Alum pollutant removal efficiency reached 86.6, 79.6, 96.6, 59.9, 39.7, 65, 59 and 95.2% for BOD, COD, TP, TN, TDS, salinity, conductivity and turbidity, respectively, with an increase in the concentration of DO of 85.3%. On the other hand, removal percent of heavy metals achieved were 82.1, 90.6, 89.1, 96.8, 93.2, 72.8, and 84.1% for Pb, Cd, Zn, Fe, Co, Ni, and Cu, respectively. The methodology carried out in this study indicated that CKD can be used as a good environmental alternative coagulant for low to moderate wasted water as it achieved removal percent similar to that achieved by the common coagulant alum.

Performance of microbubble ozonation on treated tropical peat water: Effects on THM4 and HAA5 precursor formation based on DOM hydrophobicity fractions

The hydrophobicity properties of dissolved organic matter (DOM) found in tropical peat water has an impact on the formation of carcinogenic DBPs such as trihalomethanes-4 (THM4) and haloacetic acids-5 (HAA5). This study was conducted to determine the effect of microbubble ozonation on changes in DOM fraction and its effect on the formation of THM4 and HAA5. Alum coagulation and activated carbon adsorption were carried out to reduce the DOM concentration before microbubble ozonation. Microbubble ozonation was carried out at acidic (pH 5.5), neutral (pH 7) and alkaline (pH 8.5) conditions to determine the effect of pH. Coagulation and adsorption of activated carbon were successful in reducing the presence of the hydrophobic acid fraction (HPOA) in peat water completely, but the transphilic (TPH), charged hydrophilic (HPIC) and neutral hydrophilic (HPIN) fractions remained in the water. Microbubble ozonation succeeded in decreasing the presence of TPH fraction but increased the formation of HPIC and HPIN. The degradation of the TPH fraction resulted in reduced formation of chlorinated THM4 and HAA5 (C-THM4 and C-HAA5). On the other hand, the formation of HPIC and HPIN fractions increased the formation of brominated THM4 and HAA5 (B-THM4 and B-HAA5) after the final chlorination process.

Surface Water Pollution Study for Chinnandipalayam Lake, Tirupur and Remedial Measure by Wastewater Treatment

The dyeing industry is widely recognized as the main source of water contamination. These industries dispose of wastewater in the water bodies along with the solid waste. The physicochemical characteristic of an aquatic body gets affected and estimation of these parameters provides information on water quality and pollution status. Physicochemical parameters like pH, turbidity, chlorides, hardness, total solids, dissolved solids, BOD, COD and sulphates of the surface water samples obtained at different locations near to the Chinnandipalayam Lake, Tirupur were studied to find the influence of the dyeing waste. The water samples collected were treated using natural coagulant and the removal efficiency was studied. The initial pH, Turbidity, COD of the most contaminated sample are 7.95. 21.1 NTU, 666 mg/l respectively. Natural coagulants T.foenum-graecum (Fenugreek), Cicer arietinum (Chickpea), Azadirachta indica (Neem), Moringa Oleifera (Drumstick) and Dolichos lablab (Beans) and also chemical coagulant alum were used in this study and the efficiency of reduction of turbidity using these natural coagulants are 79.6%, 80.1%, 76.8%, 80.6% and 73.0% respectively and of using alum is 95.3%. When using natural coagulant at varying levels, total solids in the sample decreased considerably. At the same time pH and conductivity are not greatly. Moringa Oleifera’s output is greater than that of other four; this depends on the protein content in the natural coagulant. but chemical coagulant has treatment efficiency of 95.3%. Even though alum has more efficiency, natural coagulant is eco-friendly and do not affect the environment after disposing the sludge and also the lake water is being used for the agricultural purpose 80% treatment efficiency can be adopted.

Efficacy of selected pretreatment processes in the mitigation of low-pressure membrane fouling and its correlation to their removal of microbial DOM

Membrane fouling by dissolved organic matter (DOM), especially microbially-derived DOM, is a major challenge for ultrafiltration (UF) membranes in water purification. Fouling may be mitigated by pretreating feed waters; however, there are no comprehensive studies that compare the fouling reduction efficacies across different pretreatment processes. Further, there is a limited understanding of the relationship between fouling reduction efficacy and microbially-derived DOM removal from source waters. Accordingly, the objectives of this study were to: (i) evaluate and compare the efficacies of five pretreatment processes in reducing UF membrane fouling by DOM; and (ii) investigate whether a relationship exists between membrane fouling reduction and microbially-derived DOM removal by pretreatment processes. We investigated seven water sources and a polyvinylidene fluoride hollow-fiber UF membrane using bench-scale fouling tests. Dissolved organic carbon content, ultraviolet absorbance and fluorescence excitation-emission matrix spectroscopy were used to assess DOM concentration and composition. Alum and ferric chloride coagulation were the most effective pretreatment processes in reducing membrane fouling, anion exchange was moderately effective, and PAC adsorption and chlorine pre-oxidation were the least effective. Consistent with previous studies, microbially-derived DOM was the major contributor to UF membrane fouling regardless of water source or pretreatment type. Fouling reduction was strongly correlated with the reduction of microbially-derived DOM in foulant layers but not from source waters. This result indicates that a fraction of the total microbially-derived DOM in feed waters was responsible for UF fouling. Overall, pretreatment processes that remove microbially-derived DOM are well-suited for UF membrane fouling reduction.

Life Cycle Analysis for Hibiscus Sabdariffa Powder Manufactured by Freeze Drying for Wastewater Application

Synthetic coagulants currently used to treat dye wastewater in the water treatment industry has been found to produce large amounts of waste and is bad for the environment. The research then presents two different methods of preparing Hibiscus Sabdariffa as a natural coagulant which are direct method and freeze-drying method to possibly replace synthetic coagulant in treating dye wastewater. The two different methods of preparing natural coagulant Hibiscus Sabdariffa are compared in terms of protein retention and coagulation performance at removing dye from dye wastewater. This is to determine which method of preparation is better at preparing a Hibiscus Sabdariffa as a natural coagulant to be used in the water treatment industry. Three analysis are done to determine the optimum concentration of Hibiscus Sabdariffa powder and freeze-drying duration is based on (i) surface morphology, (ii) water solubility and (iii) water activity. Optimum concentration of Hibiscus Sabdariffa powder is 20wt% and 24-hour freeze-drying duration. Another analysis is done to compare protein retention of each methods of preparation using (iv) Fourier Transform Infrared (FTIR) spectroscopy testing. Protein in Hibiscus Sabdariffa prepared using freeze drying is completely retained based on Fourier Transform Infrared spectroscopy results. Supporting data of protein retention properties of freeze drying is proven by water activity in Hibiscus Sabdariffa powder is at 0.478 and below the 0.6 threshold value. Water activity of 0.478 means that there is not enough water content in Hibiscus Sabdariffa powder for microorganisms to grow and degrade the protein. Optimum coagulant dosage and pH value that Hibiscus Sabdariffa prepared using the two different methods best works in is determined based on two experiments called (v) effects of coagulant dosage on dye removal percentage and (vi) effect of pH value of preparation methods on colour removal percentage. Coagulation performance of both preparation methods are also determined using experiment (v) and (vi). Hibiscus Sabdariffa prepared using freeze drying has better coagulation performance with higher colour removal percentage at lower required coagulant dosage and higher dye removal percentage at varied pH values compared to direct method. As a result, freeze drying is better in terms of coagulation performance compared to direct method at preparing natural coagulant Hibiscus Sabdariffa. Coagulation performance of natural and chemical coagulant is compared using (vii) jar test comparison between natural and chemical coagulant on colour removal. This is to determine if coagulation performance of natural coagulant is comparable to chemical coagulant. Coagulation performance of natural coagulant is only slightly lower than synthetic coagulant at colour removal percentage of 91.2% compared to 92.3%. This makes the coagulation performance of natural coagulant comparable to synthetic coagulant allowing it to be an alternative to synthetic coagulant based on coagulation performance. Therefore, Life Cycle Analysis (LCA) will then be conducted to compare the better method of preparation of natural coagulant which is freeze-drying of natural coagulant Hibiscus Sabdariffa to chemical coagulant alum. Life Cycle Analysis done is to determine, evaluate and compare natural against chemical coagulant based on 3 sustainability aspects economic, environment and social aspects. This is to determine the feasibility of natural coagulant Hibiscus Sabdariffa in the water treatment industry on whether it is a possible alternative or replacement to the currently used synthetic coagulant alum. Based on Life Cycle Analysis natural coagulant is the better alternative compared to chemical coagulant based on impact towards the environment and health and well-being of society. However, the implementation of natural coagulant in the water treatment industry is still not feasible as production cost of natural coagulant is 126.86 times more expensive compared to chemical coagulant. As a result, currently Hibiscus Sabdariffa as a natural coagulant is not able to replace synthetic coagulant alum in the water treatment industry.

Cactus opuntia as coagulant in treating landfill leachate via coagulation process

Coagulation-flocculation treatment is often used for the treatment of stabilized landfill leachate. However, uses a non-environmentally friendly chemical coagulant which is a threat to environment quality, therefore Cactus opuntia is proposed to replace the use of current chemical coagulants such as aluminium sulphate in order to achieve sustainable growth. In this regard, the comparative suitability of Cactus opuntia and alum as coagulants for the treatment of the stabilised leachate of the Padang Siding Landfill Site was evaluated via a series of Jar Test experimental works with a rapid mixing speed of 100 rpm for 3 minutes, a slow mixing speed of 30 rpm for 10 minutes and a set-up period of 30 minutes. In addition, the sludge volume index (SVI) of the treated leachate sample was calculated under optimised conditions. Cactus opuntia was able to remove 66.8 per cent turbidity and 42 per cent COD at optimal pH 2 with a favourable dose of 8000 mg / L, while the optimal pH 5 with a coagulant dose of 8000 mg / L induced 94.5 per cent turbidity and 69 per cent COD reduction from the same leachate sample. In addition, the SVI of alum coagulant was 42.2 while the Cactus opuntia was 4.45 with a relative ratio of alum to opuntia of 9:1. Cactus opuntia may also be proposed as a plentiful coagulant of metal cationic ions such as aluminium, iron and silica elements for the treatment of leachate.

Studies on Alum as Milk Coagulating Agent in the Manufacture of Paneer – An Indian Cottage Cheese

Alum is a white crystalline double sulphate of aluminum and potassium that is commonly used as an astringent. Utilising its protein binding property, alum was studied as coagulating agent of milk in the preparation of paneer. Paneer is a soft variety of cottage cheese very popular in Indian sub-continent, used in various culinary dishes. Its preparation essentially involves acid coagulation of hot milk and pressing of the hot coagulum to form a compact block which is then cooled by immersing in chilled water. Citric acid and vinegar are commonly used as coagulating agents of milk during paneer manufacture. However, when alum was used as a coagulating agent, it was observed that most of the proteins were amalgamated during coagulation process resulting in enhanced yield of paneer. It also resulted in reduced solids losses in whey. However, use of alum resulted in a slight astringency in paneer, hence it was recommended to be used in combination with common coagulant i.e. citric acid. The solids content (losses) in whey were 6.62, 6.08, and 6.32 %, respectively for citric acid, alum and citric acid + alum mixture used as coagulating agents. Similarly, the yields of paneer were 16.42, 19.04 and 16.99 %. The alum coagulated paneer looked glossy and attractive which was indicated by reflectance values of 83.75% as against 79% for control paneer sample. The paneer made by alum coagulation had slightly brittle texture.

Performance assessment of pulsating floc blanket clarifiers and conventional clariflocculators in pilot‐scale models

Continuous upflow pilot plants based on conventional clariflocculation (CC) and pulsating floc blanket clarification (PFBC) technologies were designed and fabricated for a capacity to treat about 8,000L/day, to understand the fundamental differences in their functioning and assess their relative performance, especially under low turbidity conditions. Influent turbidity varying from 2 to 10 NTU was treated using coagulant alum, and efficiency of CC and PFBC in terms of average turbidity removal was found to be 23% and 48%, respectively. On observing this vast difference, it was postulated that total residual aluminum should also be lower in water treated from PFBC. Experiments and MLR analysis confirmed the hypothesis, with residual aluminum ranging from 0.055 to 0.040mg/L and 0.036mg/L to below detectable levels for CC and PFBC, respectively. These findings are of high significance, since minimization of residual aluminum in drinking water is a priority of WHO due to its reported neurotoxicity and can be complied with simple replacement of CC with PFBC. PRACTITIONER POINTS: Pulsating floc blanket clarifier (PFBC) performed better than conventional clariflocculator (CC) in terms of turbidity removal. Pulsating floc blanket allowed more effective utilization of coagulant alum, resulting in significantly lower residual aluminum in clarified water. Turbidity levels of influent and effluent are related to residual aluminum in treated water. PFBCs are more compact and modular, and can facilitate a good alternative to CCs.