Polyelectrolyte determination in drinking water

Optimization of coagulation–flocculation process for turbidity removal using response surface methodology: a study in Ilam water treatment plant, Iran

Algae-removing and algicidal efficiencies of polydiallyldimethylammonium chloride composite coagulants in enhanced coagulation treatment of algae-containing raw water

Wastewater generated by the industry manufacturing detergents and various kinds of consumer products normally contains very high contents of mixed surfactants, organic matters expressed as chemical oxygen demand (COD), and phosphates that must be treated prior to discharge to the aquatic environment. In this study, jar-test experiments were conducted to evaluate the waste activated sludge (WAS) as a coagulation aid in the coagulation-flocculation process with ferric chloride or aluminum sulfate as a coagulant for the treatment of wastewater collected from the aforementioned industry. The WAS was selected because of its adsorption capability of anionic surfactants and its availability from the wastage stream of biological wastewater treatment process. The effective dosages of both coagulants with and without the WAS additions were determined in this study. Without the WAS addition, the concentrations of 800 mg/L aluminum sulfate at the optimum pH value of 8 and 2208 mg/L ferric chloride at the optimum pH value of 12 were the optimum chemical dosages. It appears that aluminum sulfate was more effective than ferric chloride based on the chemical dosage and removal efficiency. The turbidity, suspended particles, anionic surfactants, COD, and phosphates removal efficiencies of aluminum sulfate and ferric chloride under the optimum dosage were 95.6, 88.2, 78.4, 73.5, 47.3% and 98.8, 92.0, 72.7, 67.5, 53.1%, respectively. The addition of 200 mg/L WAS was sufficient to reduce the optimum dosages of both chemicals by 200 mg/L. The cationic surfactant existing in the wastewater worked as a flocculating agent leading to the flocculation of waste activated sludge resulting in the enmeshment of the suspended particles and colloids on which the COD, anionic surfactants, and phosphates were adsorbed. However, the substances removal efficiencies of ferric chloride and aluminum sulfate were slightly enhanced and reduced, respectively. It is possibly explained that the settling time is insufficient to settle the aluminum hydroxide floc when it is compared to the ferric hydroxide floc because the iron floc is normally heavier than the alum floc.

Behaviour of Inorganic Coagulants in Secondary Effluents from a Conventional Wastewater Treatment Plant

The environment is considered as a composite term for the condition in which organisms live. Pollution of the environment is one of the most fatal ecological crisis to which we are subjected today. Earlier these amenities were pure, undisturbed and uncontaminated for living organisms. But situation is reverse today. The impurities present in water are threat to life. The impurities present in water and wastewater is decisive factor for selection of treatment scheme. Impurities are present in water in dissolved and suspended form. The suspended impurities present in water are non- biodegradable in nature. So it is necessary to remove suspension in water and wastewater. The coagulation-flocculation method is sustainable solution for different kind of surface water, ground water, synthetic water and industrial effluents. In conventional method, inorganic coagulants are used for coagulation-flocculation. But major drawbacks are high dosage of inorganic coagulants, poor results and large quantities of sludge generation. So, organic polyelectrolytes were introduced in conjunction with inorganic coagulants for the treatment of water and wastewater.

The aim of this study was to improve the wastewater treatment plant (WWTP) efficiency of a food industry. Despite the anaerobic-aerobic treatment, the efficiency of the plant is poor because of the high pollutants load derived mainly from the use of disinfectants and sanitizers. These cleaning products are used in the production process. In order to achieve the main goal of the study, the pollutants load reduction was targeted and a physicochemical treatment was added for that purpose. For this effort, the tests were divided in three parts. The first consisted of performing coagulation-flocculation laboratory tests to select the best chemical reagent for reduction of the high load of pollutants present in the influent. The evaluated compounds were ferric chloride, aluminum sulphate, hydroxychloride of aluminum (AHC) and polyaluminum sulphate (PAS). The second was a pilot plant study in which physicochemical and biological treatment werecombined. Finally processes were verified in the WWTP characterizing the effluent and evaluating the process for compliance with standards for reuse water. The results showed that the best coagulant was hidroxichloride of aluminium. Improving the relationship Chemical Oxygen Demand/ Biological Oxygen Demand (COD/BOD5) of 0.27 to 0.45 and getting a dose of 1 to 5 mg L− 1 in the laboratory, which improved to make scaling to plant 0.5 to 2 mg L− 1 with efficiencies removal of contaminants 98% for COD, 95% for BOD5, 99% for O&G, to 99% for TSS and helminth eggs were not detect. The wastewater was characterized with cyclic voltammetry and the sludge produced with AHC was analyzed by scanning electron microscopy (SEM) and energy-dispersion spectroscopy (EDS).

A contemporary review on plant-based coagulants for applications in water treatment

Solid particles were removed from a slaughterhouse liquid effluent by physicochemical treatment (coagulation‐flocculation process) using aluminium sulfate as the coagulant, and activated silica, powdered activated carbon, precipitated calcium carbonate, polyacrylic acid, or anionic polyacrylamide as coagulant aids to improve the settling time.Once the optimal conditions of the coagulation‐flocculation process had been established (speed and time of stirring during flocculation, pH, coagulant and coagulant aid doses), the particle number and size distribution were measured before and after the addition of aluminium sulfate as the coagulant and the different coagulant aids, to determine the efficiency of the coagulation‐flocculation process. When aluminium sulfate was used without the coagulant aids, overall efficiency of particle removal was 87%. Use of powdered activated carbon, polyacrylic acid, or anionic polyacrylamide improved removal to values between 92 and 98%.

Evaluation of using aluminum sulfate and water-soluble Moringa oleifera seed lectin to reduce turbidity and toxicity of polluted stream water

Ferric chloride and aluminium sulphate as coagulants and positive charged flocculants PDDMAC ((PDDMAC = poly (diallyldimethylammonium chloride) were used for pre-treatment of water and wastewater for removing humic substance prior to RO membrane filtration. It was found that a combination of flocculant and coagulant enhanced the coagulation-flocculation process and humic acid removal. The optimum conditions of coagulation-flocculation were established in reference to the ratio of humic acid and coagulant. Zeta potential and the ratio of E4/E6 were investigated to explore the possible micro-mechanisms of coagulation-flocculation. The ratios of E4/E6 show the molecular size variations using different coagulants and flocculants, which are expected to benefit membrane-fouling control.

The objective of this study is to compare organic and inorganic coagulants in coagulation-flocculation and sedimentation, using a jar test apparatus. Six types of coagulants, namely extract solution of moringa oleifera seed with distillation water (Moringa-H), extract solution of moringa oleifera with sodium chloride (Moringa-N), Micro-nice®bio separator A from Technogreen Limited, aluminium sulfate (alum), ferric chloride (FeCl3) and polyaluminium chloride (PAC) were investigated using three types of synthetic wastewater, kaolin suspension, soymilk solution and oily wastewater for determination of the optimum dosage and coagulation mechanism. The results indicated that PAC was able to remove turbidity of 90-94%, pH in the range of 6-7 in the kaolin suspension concentration range of 20-100 mg/L, while the Moringa-H showed turbidity removal of 66-91% which was better than Moringa-N and dry sediment using Micro-Nice®gave minimum sludge. The Micro-Nice®also showed high turbidity removal in colloid and oily wastewater. The optimum dosage of Micro-Nice®was in the range of 80-120 mg/L for colloid removal of 89-96% and COD removal of 37-73% at the colloid concentration range of 100-1000 mg/L, while 10 g/L oily wastewater showed that the optimum dosage of Micro-Nice®was 200 mg/L for turbidity removal of 99%, COD removal of 73% and oil removal of 97%.

Variables affecting melanoidins removal from molasses wastewater by coagulation/flocculation

Turbidity is one of the of drinking water treatment problems. Turbid water contains molecules, plankton and colloids, is dealt with through the addition of coagulation chemicals in a process called coagulation and flocculation. In this research, three of the most commonly used coagulants used in water treatment process were examined for their efficiency in reducing turbidity. Those are Aluminum sulfate (alum), Ferric chloride and Poly aluminum chloride (PACl). Experiments were conducted using synthetically prepared turbid water by adding kaolin and using a Jar test instrument to define the optimum dosage from each chemical. The tests were conducted for two turbidity levels; 52 and 580 NTU. The results showed that Poly aluminum chloride is more efficient than both alum and ferric chloride. A dosage of 75 mg/l from PACl reduces the turbidity of the water from 580 to 4.55 NTU (99.2%), and from 52 to 1.5 NTU (97.1%). Applying the same operating conditions, Alum and FeCl3 should be a lower efficiency for turbidity removal. The efficiency of Alum and Ferric were 98.5% and 93.8% for water with 580 NTU, and 98.8% and 86.1% for water with 52 NTU.

Water is one of the essential components of nature, frequently polluted by agricultural, industrial, and man-made activities. The exponential growth of population and industrial development has made potable water a rare commodity (Szygu et al. 2009). Chitosan, a biopolymer, is an aminopolysaccharide composed of glucosamine, 2-amino-2-deoxy-β-dglucose. It is prepared by alkaline deacetylation of chitin, a biopolymer extracted from shell sh sources. Chitosan exhibits a variety of physicochemical and biological properties, which could be used in the elds of biotechnology, agriculture, textile, biomedical engineering, food processing, pharmaceuticals, and ophthalmology. It is a weak cationic base insoluble in water and organic solvent but soluble in aqueous acidic solution with many amine (–NH2) and hydroxyl (–OH) groups and acts as a chelate to form complex with metal ion (Zeng et al. 2008, Bina et al. 2009, Renault et al. 2009). The nature of the pollutants present in the water and wastewater depends on the source generation that varies from place to place (Bhatnagar and Sillanpa 2009). Chitosan has been widely used for water treatment to remove the pollutants. It is a well-known biosorbent for metal cations; the reactive amino group binds with metal ion to remove the metal present in the water by ion exchange. Several methods have been used to modify the natural chitosan in order toCONTENTS38.1 Introduction ........................................................................................................................ 747 38.2 Physicochemical Characteristics of Chitosan ................................................................ 74838.2.1 Chitosan as Natural Flocculants or Coagulant ................................................. 749 38.2.2 Separation of Water from Alcohol Mixture ....................................................... 749 38.2.3 Recoveries of Protein from Surimi Wash Water ................................................ 749 38.2.4 Removal of Dyes .................................................................................................... 750 38.2.5 Removal of Phenol ................................................................................................. 750 38.2.6 Removal of Fluoride .............................................................................................. 750 38.2.7 Removal of Metal Ions........................................................................................... 753 38.2.8 Removal of Nitrate ................................................................................................. 75338.3 Conclusion .......................................................................................................................... 758 References ..................................................................................................................................... 759improve the adsorption capacity (Miretzky and Cirelli 2009). Water treatment plants face many problems when removing turbidity from raw untreated water to produce drinking water. Inorganic coagulants such as aluminum sulfate (alum) and polyaluminum chloride have been widely used for the removal of raw water turbidity because it is costeffective and easy to handle. However, the sludge obtained from those treatment leads to disposal problems and contains higher aluminum in treated water. Cationic polyelectrolytes have been used as effective coagulants or occulants in which chitosan, a biodegradable, nontoxic, and high-molecular-weight polymer, has also been used as an eco-friendly coagulant and occulant (Chatterjee et al. 2009).

In this study, co-pretreatment of municipal wastewater (MW) and landfill leachate (LL) was investigated by means of coagulation using ferric chloride and aluminum sulfate. The effects of operating conditions on process performance were examined, which included pH, coagulant type and coagulant dose. For both coagulants, the best removal efficiency was achieved at the initial pH of 5. At this pH, the removal efficiencies of chemical oxygen demand (COD), suspended solids (SS) and turbidity were 82%, %99 and %99, respectively with ferric chloride and 72%, 98% and 98.5%, respectively with aluminum sulfate. For the ratios ranging between 10:1 and 5:1 of MW to LL, the optimum dose was determined as 500 mg/L for both coagulants. When the ratio of MW to LL was reduced from 5:1 to 1:1, the coagulant dose required was raised from 500 to 1000 mg/L and the removal efficiency of pollutants reduced. Better removal efficiencies were achieved by ferric chloride in comparison to aluminum sulfate. The results revealed that coagulation could be applied as pretreatment for co-treatment of MW and LL.