Optimum Coagulant Dose Research Articles

Potential reuse of sludge from a potable water treatment plant in Al Hoceima city in northern Morocco

Producing potable water generates a large amount of sludge, which consumes energy and must be managed and controlled. A case study of a potable water production plant in Al Hoceima City in northern Morocco is described here. The plant produces 15000 ​m3 of potable water each day to meet the water demand of Al Hoceima City, and this causes 3 ​t of sludge to be produced each day. Sludge extracted while producing potable water was characterized, and the possibility of reusing the sludge rather than disposing of it directly to the environment was assessed. The pH, turbidity, aluminum content, and other characteristics of the sludge were determined. Jar tests were performed to determine the optimum coagulant (aluminum sulfate) dose to ensure that the minimum required amount of aluminum sulfate was used. The characterization results indicated that the sludge was stable and reusable. The jar-test results allowed the amount of coagulant used to be optimized and will lead to markedly less sludge being disposed of than is currently the case.

Turbidity removal through the application of powdered azadirachta indica (neem) seeds

Various natural products used for water treatment are becoming more popular due to their general safety, eco-friendly sludge production, ease of degradation, cost-effectiveness, and local availability. This research assessed the efficiency of powdered neem (Azadirachta indica) seeds in removing turbidity from the water. Batch experiments determined the optimum coagulant dose, pH level, mixing time, and mixing speed to reduce turbidity from kaolin-based synthetic turbid water. Powdered neem seeds with a pore size of about 0.45 mm were prepared and used in water treatment under optimum conditions. Results showed that a coagulant dose of 3 g of neem seeds/L, 13.2 pH level, 60 mins mixing time at 80 rpm mixing speed could reduce turbidity levels to 35 NTU from 250 NTU (86% removal). Findings suggest that powdered neem seeds can be a potential substitute for conventional chemical coagulants for drinking water treatment.

Brewery Effluent Treatment with Conventional and Natural Coagulants

In water scarce countries such as Eritrea, maintaining brewery industry remain ever challenging task. Currently, Asmara breweries is the only beer producing factory consuming 8.46 L of water per every L of beer produced which is notably higher than Brewer’s Association (BA) benchmark and consequently generates 7.53 L of wastewater/L of beer. Bottle cleaning and brewery activities ascertain ample effluent bases. Wastewater from bottle cleaning (BCWW), brewery (BWW) and mixed (MWW) have attributed a wide spectrum of 3500-160000 mg/L of COD and 327-26667 mg/L of BOD<sub>5</sub>, which are significantly overtops other reported brewery effluents. Physicochemical treatments including coagulation with conventional (alum) and natural (MO seed) flocculants have tested to remove higher COD and BOD<sub>5 </sub>concentrations of brewery effluents. Optimal coagulant dosage determined by accounting turbidity as a key performance indicator. Alum treatment of BCWW and MO seed flocculation of MWW have resulted in lower turbidity levels of 0.49 and 6.17 NTU at 60 mg/L of dosages respectively. The optimal quantities of 92.2 % and 86.6% (by weight) of water recovered from alum treatment of BCWW and MO seed coagulation of MWW respectively. Higher sludge volumes recorded as a major disadvantage in alum coagulation whereas natural coagulant, MO seed manifested competitive results in removal of COD, BOD<sub>5</sub>, Chlorine, Nitrogen, Sulphate, Sodium, TDS and TSS along with P<sup>H</sup> stabilization. In addition, 97.2% of influent turbidity removed through MO seed coagulation treatment, an equipollent to alum despite of four fold increment in potassium levels.

A comparative analysis of degradation efficiencies using alum and orange peel waste for the treatment of tannery wastewater

The tannery wastewater effluent consists of complex compounds requiring a series of treatment processes to meet the desirable effluent discharge standards. The current study deals with the comparison of degradation efficiencies obtained in terms of turbidity, total suspended solids (TSS) and chemical oxygen demand (COD) removal by using alum as a chemical coagulant, orange peel powder (OPP) and activated orange peel powder (AOPP) as naturally obtained adsorbents respectively. The experimental analysis showed that the maximum COD reduction of 49 % approx. was obtained using AOPP at optimum coagulant dosage of 2 g/L, at pH 4 and flocculation time of 30 min. Scanning Electron Microscope (SEM) showed that the AOPP consists of porous structure that leads to adsorption of pollutants over the surface. Brunauer–Emmett–Teller (BET) analysis resulted in surface area reduction of AOPP from 11.663 m2/g to 1.289 m2/g before and after adsorption correlating the experimental results of the study. Moreover, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Total organic carbon (TOC) proved that the chemical properties also play an important role in degrading the pollutants present in TWE. It can be concluded that the AOPP can be used as a cost-efficient alternative for pre-treatment of TWE.

Application of tannin-based coagulant for high-range turbidity surface water clarification

Abstract This study aimed to evaluate the performance of a tannin-based coagulant in clarifying drinking water from a high-range turbidity river and characterizing the sludge. Tanfloc MTH product was selected for this investigation. The study site was surface water located in southern Brazil (Caveiras River, Brazil). Samples were collected just before the Parshall flume in the municipal water treatment plant in Lages (Brazil) for nine months, at least once a week. Jar testing evaluated turbidity removal, alkalinity consumption, optimal coagulant dosage, and settling velocity. After flocculation and settling, the sludge generated from the jar test was submitted to metal and thermogravimetric analyses. The use of tannin reduced the average water turbidity from 26.1 ± 56.1 to 0.94 ± 0.26 NTU, apparent color from 145 ± 190 to 3 ± 3 Pt-Co, and there was no variation in the pH. Additionally, the settling velocity of the flocs reached a maximum turbidity removal at 3.5 cm·min−1. Furthermore, the metal concentrations in the sludge showed a majority of aluminum and iron, and thermogravimetric analysis revealed 64% weight loss. In conclusion, Tanfloc presented the potential to be used in surface water clarification from the Caveiras river, and the extensive turbidity range observed during this study did not affect the operational stability.

The Effectiveness of Moringa Oleifera in Purifying Pegasius SP Pond Wastewater

Pond water of silver catfish (Pangasius sp) has high color value, turbidity, and organic compound with the color concentration 250 Pt-Co, turbidity 13.5 NTU, and organic concentration 197.56 mg/L. High concentration of color, turbidity, and organic compound in pond water of silver catfish caused the water should be treated. One of the treatment method is chemical treatment with coagulation-flocculation method. Pond water of silver catfish was treated into clean water using powder of Moringa seed (Moringa oleifera) as organic coagulant using coagulation-flocculation method with Jar-Test system. The aim of this research is to purify water with knowing the removal efficiency of color, turbidity, and organic compound by treating pond water of silver catfish using coagulation-flocculation method and determining optimum dose of coagulant. Jar-Test result showed the color removal efficiency as 86.00% in day 1; 90.75% in day 2; and 88.77% in day 3 with 60 ppm as optimum dose. Turbidity removal efficiency was 84,52% in day 1 and 87.80% in day 2 with 60 ppm as optimum dose. Organic compound removal efficiency was 73.87% in day 1; 77.13% in day 2, and 77.29% in day 3 with 60 ppm as optimum dose.

Efektivitas Koagulan Terhadap Penurunan Energi Potensial Pada Pengolahan Air di PDAM Tirta Pakuan Kota Bogor

In the processing of raw water into clean water need to add coagulant to remove turbidity when the turbidity exceeds the limit specified requirements. Coagulant commonly used for water treatment that Poly Aluminum Chloride (PAC), Aluminum Sulfate and Ferry Chloride. This study aims to determine the optimum dose of coagulant Poly Aluminum Chloride (PAC), Aluminum Sulfate and Ferry Chloride and to compare its effectiveness in water treatment Cisadane in PDAM Tirta Pakun Bogor with different turbidity levels.Cisadane river water sample taken on different days with different turbidity levels. Determination of the optimum dose of coagulant is done by providing different dosage variations. Test parameter and characteristics of raw ait water jar test result of the test, to test the turbidity mearused by the turbidymeter total dissolved solids mearused by conductometer, pH mearused by pH meter, Fe and Mn measured by spectrophotometer and organic substance using titration method. Then the experimental data obtained were compared with the reqquirements of Permenkes No. 492/Menkes/iv/2010.Of the result obtained optimum dose at low turbidity coagulant Poly Aluminum Chloride (PAC) 30,2 NTU at 14 mg/L and Ferry Chloride at 16 mg/L.. While high turbidity of 681 NTU, the optimum dose for coagulant Poly Aluminum Chloride (PAC) at 35 mg/L, Aluminum Sulfate at 5 mg/L and Ferry Chloride at 40 mg/L. Coagulant more effective water treatment raw cisadane river in the PDAM Tirta Pakuan Bogor is coagulant Poly Aluminum Chloride(PAC). Because Poli Aluminium chloride is more effective in reducing potential energy as a barrier energy in the aggregation process.

Combination of Coagulation and VUV+H2O2 for the Treatment of Color and Organic Matter in Treated Effluent Wastewater from a Sugar Factory

The removal of color and organic matter in treated effluent wastewater from a sugar factory by coagulation, combined with advanced oxidation processes (AOPs), including UV, UV+ hydrogen peroxide (UV+H2O2), vacuum UV (VUV), and VUV+H2O2, was investigated in this study. The effect of pH and a dose of coagulants (aluminum sulfate (alum), polyaluminium chloride (PACl), ferric chloride (FeCl3), and ferric sulfate (Fe2(SO4)3)), as a pretreatment step prior to AOPs, was analyzed. The optimum pH and coagulant dose for coagulation was pH 6 and 600 mg/L, respectively. The iron-based coagulants generally provided the better removal efficiency than the aluminium-based coagulants. Among four coagulants, FeCl3 was chosen for use in the pretreatment step since it provided the best performance for dissolved organic carbon (DOC) removal, UV transmission improvement, and cost-effectiveness. The removal efficiency and degradation rate of color, UV absorbance at 254 nm (UV254), and DOC increased along with the H2O2 dosage. The reduction of UV254 indicated a less aromatic portion of DOC after AOPs. The ratio of DOC:H2O2 at 1:3 yielded the highest DOC removal of 70 ± 0.42 and 73 ± 0.19% in 60 min by UV+H2O2 and VUV+H2O2, respectively. For energy efficiency, VUV+H2O2 (DOC:H2O2 =1:3) provided the lowest electrical energy per order (EEO) (26 kWh/m3). After coagulation, DOC combined with VUV+H2O2 was reduced to the appropriate level for reuse (4 mg/L). The findings from this research demonstrate the promise of coagulation coupled with the VUV+H2O2 process as a technology for water reuse application in the sugar industry.

Application of a 2k–p Fractional Experimental Design in Coagulation-Flocculation Processes in the Treatment of Wastewater from a Slaughterhouse

Determining the optimal dose of coagulant required to perform flocculation is critical in most water treatment plants’ planning and operation. This study implemented a 2k–p fractional factorial design of experiments to identify the factors influencing the color decrease of wastewater from a slaughterhouse. The variables assessed were the velocity gradient, residence time, primary coagulant dosage, chlorine dosage, and coagulation adjuvant dosage. The results indicate that the primary coagulant dose and the velocity gradient significantly affect the samples’ color and that the other factors can be run at a low technical-economic level to start up the water treatment plant. The fractional factorial design allowed reducing the number of experimental points without affecting the minimum information required to identify which factors are significant in reducing the color of a wastewater sample.

Performance of coagulation-flocculation followed by ultra-violet/ultrasound activated persulfate/hydrogen peroxide for landfill leachate treatment

The advanced oxidation processes (AOPs) were assessed for enhancing the treatment of stabilized landfill leachate previously pretreated using coagulation-flocculation (C-F).The primary treatment by C-F using 20 g.L−1 of FeCl3 (optimal coagulant dosage) has removed 71% of chemical oxidation demand (COD) and 95% of turbidity. Thereafter, secondary treatment was applied using different system combinations of two inorganic oxidants (potassium persulfate, K2S2O8 (PS) (1500 mg. L−1) and hydrogen peroxide, H2O2 (1327 mg. L−1)) that were used simultaneously or separately with UV-A and/or ultrasonic (US) irradiations.The obtained results indicated that the oxidation systems with the presence of H2O2 were more efficient than other systems. Indeed, the H2O2-PS-US-UV-A system reached the highest COD removal of 89%, while PS-based combinations were the less efficient (PS alone 19%, PS-UV-A 22%, PS-US 32%, and PS-US-UV-A 35%).Hence, the sequential process including C-F as pretreatment followed by the application of the H2O2-PS-US-UV-A system has proven high efficiency for COD removal, absorbance at 254 nm, and color number of 97%, 97%, and 99%, respectively.The sequential application of AOPs after preliminary treatment using coagulation-flocculation is a promising alternative to reducing the high organic load of stabilized leachate and that could be largely applied to other types of effluents.

Evaluation of a biocoagulant from devilfish invasive species for the removal of contaminants in ceramic industry wastewater

This study evaluated the effectiveness of a biocoagulant produced from the devilfish invasive species and its combination with two chemical coagulants (aluminum sulfate and ferric sulfate) to remove turbidity, chemical oxygen demand, and total suspended solids in ceramic industry wastewater using a combined experimental design of Mixture-Process. This design optimized the coagulation process and evaluated the effects and interactions between mixture components and coagulant doses. An analysis of variance was used to analyze the experimental data obtained in the study, and the response surface plots by response type (turbidity, chemical oxygen demand, and total suspended solids) were obtained. Results showed that the coagulation treatment could be technically and economically feasible since efficiencies of turbidity, chemical oxygen demand, and total suspended solids removal of 74, 79, and 94% could be achieved using an optimal coagulant dose of 800 mg/L with a mixture of 35% biocoagulant and 65% ferric sulfate. Analysis of variance results showed that the models are significant, and the lack of fit is not required according to the probability value (p value), which were < 0.0001, and > 0.05, respectively. Hence, the experimental data were fitted to a combined reduced special cubic x linear model. These results support the use of devilfish meal as a biocoagulant, being more feasible in dual systems when mixed with ferric sulfate.

Determination of optimum coagulant dosage in the treatment of abattoir wastewater, using calcium hydroxide as coagulant

This research was carried out to evaluate the effective and efficient treatment of abattoir wastewater using calcium hydroxide coagulant. Samples were collected from an abattoir unit in Ikpoba-Okha Local Government Area, Benin City, Edo State. The raw samples were characterized to determine: Dissolved oxygen (DO), chemical oxygen demand (COD), biochemical oxygen demand (BOD), temperature (T), pH, electrical conductivity (EC), turbidity, total dissolved solids (TDS), total suspended solids (TSS), total alkalinity (Alk), chloride, total Kjeldhal nitrogen (TN), hardness, potassium, phosphorous and total bacteria count (TBC). Thereafter, the samples were treated with several doses of calcium hydroxide coagulant (2g, 4g, 6g, 8g, 10g, 12g, 14g, and 16g). Results obtained were used to determine the optimum coagulant dosage in a plot of percentage COD against masses of coagulants used. From the optimum dose obtained (12g Ca(OH)2), a batch treatment was carried out. The treated wastewater was further characterized to ascertain compositional changes. Result revealed increase in oxygen and substantial reduction in chemical oxygen demand, total nitrogen, phosphorus and turbidity. Biochemical oxygen demand and total solids were also reduced. The treated effluent could be discharged into the environment without fear of pollution and may be reused for agricultural purposes.

Determination of cost-effective optimum coagulant dosage for removal of disinfection by-product precursors in water treatment based on the theory of elasticity

Determination of coagulant dosage in drinking water treatment is related to the requirements for drinking water quality as well as the treatment costs. Selection of appropriate coagulant dosages has been an issue for water treatment utilities, though empirical approaches were normally considered or employed. Inspired by the theory of elasticity in microeconomics, this study explored a novel approach for the cost-effective optimum coagulant dosage. This could enable water utilities to achieve the maximum possible removal efficiency of precursors for disinfection byproducts (DBPs) while maintain an economical dosage without incurring an excessive cost. The relationships between DBP formation potential (DBPFP) and several relevant water quality parameters were first examined and evaluated. UV254 was found the most appropriate DBPFP indicator with the highest correlation coefficients. Based on the relationship of UV254 and DBPFP, an approach for determination of cost-effective optimum coagulant dosage was delineated. The results showed that use of the cost-effective optimum coagulant dosage, which account for approximately 33% of optimum coagulant dosage, could achieve 79% of maximum removal efficiencies of UV254 for the source waters tested, thereby substantially reducing the formation of DBPs. Further increase the coagulant dosage was believed uneconomical since the increase in UV254 removal was limited. Similar results were obtained with different coagulants and with raw water samples with diverse water qualities. The results suggest that the proposed approach could provide a mathematical tool for cost-effective optimum coagulant dosage control which could at the same time achieve sufficient removal of natural organic matter to reduce DBPs formation.

Experimental application of a zero-point charge based on pH as a simple indicator of microplastic particle aggregation

Micro/nanoplastics – a useful but threatening material – continuously require fundamental research on its behaviors and properties for aggregation. Zeta potential (ζ) has been using as an indicator to determine the optimal aggregation for particle removal in water treatment processes. In the field work, however, an alternative method for streamlining these tasks and reducing the variability in processing efficiency is necessary. To improve practical utility in the field work, this study aimed at investigating applicability of the zero-point charge (ZPC) of the isoelectric point (IEP; ψpI) as an alternative indicator for aggregation in place of ζ. For the purpose, this study conducted laboratory experiments and model simulations. The experiments measured ψpI of microplastics in a trivalent-electrolyte aqueous solution using various concentrations of polyaluminum chloride (PAC) for reproducing the behavior of microplastics in natural water environments. As a result, ψpI for polyethylene (PE) and polyvinylchloride (PVC) were found to be pH 6.59 and 6.43, respectively. The removal rates (r) depended on the aggregation at the initial pH and optimal PAC concentration. The experimental attachment efficiency (αE), 0.14 to 0.4, showed a good correlation of over 95% with r, 0.04 to 0.84, both based on the pH change and PAC concentration and differing slightly with the type and size of the plastic. The highest αE was achieved with the highest r when ψpI was close to zero in the pH range of 6–8 using the optimized PAC concentration. Based on the experimental results, the model confirmed the applicability of ψpI instead of ζ as an indicator of the aggregation by simulating αE based on ψpI and ionic strength, which are themselves based on the change in pH. Therefore, this study provides some insights into behaviors of microplastics by using the isoelectric point (IEP, ψpI) as an indicator of aggregation of microplastics in place of ζ. The IEP method is limited by initial pH, optimal dosage of coagulant, and type and size of microplastics, but it will increase practical utility in the field.

Online colloidal particle monitoring for controlled coagulation pretreatment to lower microfiltration membrane fouling at a potable water reuse facility

Fouling of microfiltration (MF)) membranes during water/wastewater treatment is predominantly caused by colloidal particles (size <1 µm) in the feed water. Until recently no online technology was available to directly measure the occurrence of colloidal particles in these waters. This study evaluated the viability of a novel online light scattering technology (Nanoparticle Tracking Analysis) to continuously monitor colloidal particles in the membrane feed water (a secondary-treated wastewater) for targeted removal by injecting coagulant at a dosage proportional to the measured concentration of colloidal particles. A diurnal variation was observed in the colloidal particle concentration in the feed water with the lowest concentration occurring at approximately 6 am and the highest concentration occurring after mid-day. The peak colloidal particle concentrations were 4 to 6 times higher than the lowest concentrations measured on the same day. Bench-scale studies were performed to develop a relationship between colloidal particle concentration and the optimum coagulant dosage required for their removal. Subsequently, a pilot-scale study was performed using two MF pilot units operated in parallel, one receiving targeted coagulant dosing and the other with no coagulant dosing, to demonstrate the effectiveness of targeted coagulant dosing in preventing membrane fouling. The pilot unit that received targeted coagulant dose experienced only 4 to 20% of the transmembrane pressure increase of the increase experienced by the pilot unit that received no coagulant. Evaluation of fouling resistance indicated that targeted coagulation improved flux by predominantly lowering the irreversible fouling. The filtrate water quality measured by colloidal particle concentration, chemical oxygen demand (COD), and turbidity were very similar for the two pilot units. This suggests that although the efficiency of particle and organic materials removal does not change with coagulant addition, the particles filtered by the membrane in the control unit contributed to membrane irreversible fouling, while in the coagulant-treated unit, the coagulated colloidal particles were removed away from the membrane into the backwash stream during the frequent backwash/air scour procedures.

Moringa oleifera-derived coagulants for water treatment: Floc structure, residual organics, and performance trade-offs.

The study explored the suitability of unfractionated extracts from the seeds of the Moringa oleifera tree as a coagulant for water treatment. The coagulant was obtained by soaking crushed and sieved seeds in a low salinity aqueous solution: a simple and inexpensive alternative to conventional coagulants in settings where specialized expertise and equipment are lacking. The performance of M. oleifera-derived coagulants was quantified in terms of turbidity removal, bacteriophage clearance, concentration of residual organics, as well as meta-parameters such as floc size and fractal dimension. Treating high turbidity clay suspensions at the optimal coagulant dosage (14.7mg(DOC)/L) and flocculation mixing conditions ([Formula: see text]= 22.4s-1) removed > 94% of turbidity, similar to that recorded in reference tests with alum. Floc size distribution shifted to larger sizes during the first 10min of flocculation with no change afterwards, while the floc fractal dimension, [Formula: see text], continued to increase, pointing to the gradual formation of denser ([Formula: see text]= 2.1 to 2.2), more settleable flocs. Preliminary tests with MS2 bacteriophage showed that coagulation with M. oleifera decreased the viable MS2 titre by ~ 1.3log, which was significantly above the turbidity removal (~ 1log). The extraction process, however, allowed a large amount of residual organics (> 78% of extracted DOC) into the treated water. Combining the coagulants with downstream filtration and adsorption, employing UV or solar disinfection, or limiting applications to non-potable reuse is suggested for mitigating the concerns related to residual DOC.

Serbuk Biji Asam Jawa (Tamarin Dusindica L) untuk Pengelolaan Limbah Industri Cair Tempe (Studi Kasus Mataram)

Most of the tempe industry have not been equipped with a waste water treatment unit. It is usually a water soaked soybeans and soybean excess water is still discharged directly in the into the environment. Liquid waste industrial of tempeh contain high organic materials. One of the process for wastewater treatment is coagulation with the addition of a positively charged polyelectrolyte in tempeh wastewater as negatively charged. One of plants in Indonesia that can be used as an alternative coagulant is tamarind seeds (Tamarindus indica, L).it can be used for wastewater treatment is more economical. The aims of this experiment is to determine the optimum stirring time, optimum pH of the waste and optimum coagulant dosage for treatment of the tempeh wastewater with coagulant tamarind seed powder. The experiment studied were stirring time, the pH of thetempeh wastewater and coagulant dosage to the percentage decrease in turbidity and COD (Chemical Oxygen Demand). The variables in the experiment were stirring time (10,15, 20, 25 and 30 minutes), the pH of the waste (3; 3.5; 4; 4 and 5) and the dosage of tamarind seed powder (100, 300, 500, 700, and 900 mg / L). COD testing methods is closed reflux method by spectrophotometry and turbidity testing using Turbidimeter. The results showed that the with coagulant tamarind seed powder effectively lowered cod levels and the dryness of tempeh liquid industrial waste. The optimum pH obtained is pH 4, optimum stirring time is 25 minutes and the increase in optimum coagulant dose is 500 mg with a percentage decrease in COD levels and noise by 90.57% and 78.94%. Key words: liquid waste; sour power; turbidity; COD

Effect of clariflocculator and pulsator based sedimentation technology and poly-aluminium chloride coagulant type on the efficiency of the water treatment plant

Abstract Polyaluminium chloride (PAC) with different basicity is used as a coagulant in most drinking water treatment plants (WTP). The aluminium concentration in PAC and its hydrolysis mechanism varied with the basicity of PAC. Incremental addition of PAC changes various physico-chemical properties and turbidity removal mechanisms in water. Water treatment plants use the PAC concentration beyond its optimum dose without considering other aspects, including residual aluminium concentration. In the present work, the effect of high and medium basicity of PAC on different physico-chemical properties like pH, zeta potential, and residual aluminium concentration of water was investigated. The pH of treated water decreases with the incremental addition of PAC, and an increase in zeta potential and residual aluminium concentration in treated water was evidenced. The change in pH after PAC addition is responsible for deciding the coagulation mechanism and efficiency of the coagulation process. pH reduction is comparatively more in high basicity PAC than medium basicity. PAC hydrolysis mechanism is controlled by the zeta potential of water and can be used as an alternative method to decide the optimum coagulant dose. The performance of clariflocculator and pulsator-based WTP was also evaluated for raw water from the same source. To reduce down the turbidity below the acceptable level, the coagulant requirement for clariflocculator based WTP is comparatively less than pulsator based WTP. The floc blanket in the pulsator gets disturbed with a slight change in the coagulant chemistry and quantity.

Performance evaluation of composite coagulant in treating textile wastewater

Our modernized world needs colourful cloths. As per the requirements we need textile industries to fulfil the demands. These industries need a huge quantity of freshwater for dyeing. As a result, a large amount of wastewater is released. The released wastewater starts to contaminate natural sources and leads to several serious environmental health problems. Coagulation is one of the techniques which is used to treat all these wastewaters of various industries. In this paper, a composite coagulant of Polyaluminium chloride (PACl) and polyamine is used to remove colour of the textile wastewater. The optimum coagulant dosage and pH values were determined by comparing colour removal efficiency. It was found that 1:1 ratio gives the optimum result at pH 5 for the optimum dosage of 600 mg/L with the 95% decolourisation. Finally, the treatment of the actual textile wastewater has shown that PACl-polyamine is an effective composite coagulant.

Utilization of citrus microcarpa peels and papaya seeds as a natural coagulant for turbidity removal

Coagulation and flocculation are an essential component of both the treatment of drinking water and the treatment of wastewater. The coagulant is one of the materials or substances that is added to the water to remove, stabilizes and causes colloidal particles to settle. Chemical coagulants such as aluminum sulphate (alum), ferric chloride, and synthetic polymers are the most commonly used coagulants in the industry due to their efficacy in turbidity removal. However, the use of chemical-based coagulants has had some negative impacts on human health and the environment, such as Alzheimer’s disease, and has produced a high volume of toxic sludge. In order to reduce negative impacts, this led to the discovery of an alternative to the natural coagulant (plant-based) for drinking water treatment. The coagulant used in this study is a combination of fruit waste containing citrus microcarpa peels and papaya seed with a ratio of 80:20 and 40:60. In addition to determining the potential of the composite natural coagulant, the optimal dosage and the effect of the mixing duration are also studied in order to determine the best mixing duration for each stage of the coagulation-flocculation process. Laboratory-scale studies using jar test experiments were conducted on surface water to determine the percentage of turbidity removal. Fruit waste was collected from the UiTM Pulau Pinang cafeteria, dried in the oven for 24 hours at a temperature of 105°C. The optimum dosage of composite natural coagulant is 90 mg/L using an 80:20 ratio of citrus microcarpa peels and papaya seeds with 97% of turbidity removal. The optimum mixing time is determined where the fast mixing time is 180 rpm for 3 minutes, the slow mixing time is 20 minutes with 10 rpm and the settling time is 30 minutes. The study shows that citrus microcarpa peels and papaya seeds have the potential to become effective natural coagulants in the future.