Polyaluminum Chloride Research Articles

Comparing the effects of Al-based coagulants in waste activated sludge anaerobic digestion: Methane yield, kinetics and sludge implications

Due to its effectiveness and ease of application, the process of flocculation and coagulation is often used for pollution removal in wastewater treatment. Most of these coagulants precipitate and accumulate in waste activated sludge (WAS), and could negatively affect sludge treatments, as observed for anaerobic digestion. Nowadays, wastewater treatment plants (WWTPs) are widely discussed because of the current paradigm shift from linear to circular economy, and the treatments performed at the facility should be planned to avoid or reduce adverse effects on other processes. The aim of this study was to compare the impact of poly aluminum chloride (PAC) and aluminum sulfate (AS) on WAS anaerobic digestion, by feeding replicate serum reactors with different levels of coagulant (5, 10 and 20 mg Al/g TS). Reactors without the addition of any coagulants represented the control group. Results revealed that Al-based coagulants inhibited methane production, which decreased as the coagulant addition increased. The inhibition was much more severe in AS-conditioned reactors, showing average reductions in methane yield from 14.4 to 31.7%, compared to the control (167.76 ± 1.88 mL CH4/g VS). Analytical analysis, FTIR and SEM investigations revealed that the addition of coagulants affected the initial conditions of the anaerobic reactors, penalizing the solubilization, hydrolysis and acidogenesis phases. Furthermore, the massive formation of H2S in AS-conditioned reactors played a key role in the suppression of methane phase. On the other hand, the use of coagulant can promote the accumulation and recovery of nutrient in WAS, especially in terms of phosphorus. Our findings will expand research knowledge in this field and guide stakeholders in the choice of coagulants at full scale plant. Future research should focus on reducing the effect of coagulants on methane production by modifying or testing new types of flocculants.

Production of ceramic membranes made from porang (Amorphophallus muelleri B.) and zeolite and its utilization on jumputan wastewater treatment

Palembang has a rich art of weaving jumputan cloth. Jumputan fabric uses naphthol as a dye which if discharged into the river will affect the water. Porang (Amorphophallus muelleri B.) and zeolite have potential as absorbents in absorbing impurities in liquid waste from jumputan cloth through its modification into membranes. The purpose of this study was to determine the formulation and effectiveness of ceramic membranes from porang tubers and zeolites in treating jumputan cloth wastewater, and to characterize the permeate results from the membrane. This research uses ceramic membrane filtration method combined with coagulation using Poly Aluminum Chloride (PAC) and quicklime. Coagulation uses two stirring methods, namely fast and slow stirring. Filtration was carried out for 125 minutes and every 25 minutes the filtrate was sampled. After the filtration process, several parameters were analyzed, namely turbidity, color, TSS, and pH. The best turbidity value reduction was shown in membrane variation 2 at 50 minutes with a decrease of 68.71 %, a decrease in color concentration was shown in membrane variation 2 at 75 minutes operating time with a decrease of 69.19%, the decrease in TSS value is shown in membrane 2 at an operating time of 125 minutes with a decrease of 81.03 %. The highest pH increase was found in membrane variation 1 at an operating time of 125 minutes with an increase of 42.67 %. The filtration process with ceramic membranes is effective in reducing turbidity, color concentration, TSS, and increasing the pH of the waste.

Multi-Objective Optimization Based on Simulation Integrated Pareto Analysis to Achieve Low-Carbon and Economical Operation of a Wastewater Treatment Plant

It is essential to reduce carbon emissions in wastewater treatment plants (WWTPs) to achieve carbon neutrality in society. However, current optimization of WWTPs prioritizes the operation cost index (OCI) and effluent quality index (EQI) over greenhouse gas (GHG) emissions. This study aims to conduct a multi-objective optimization of a WWTP, considering GHG emissions, EQI, and OCI. The anaerobic-anoxic-oxic integrated membrane bioreactor (AAO-MBR) process in an actual WWTP was selected as a typical case, tens of thousands of scenarios with combinations of six operational parameters (dissolved oxygen (DO), external carbon resource (ECR), poly aluminum chloride (PAC), internal reflux ratio (IRR), external reflux ratio (ERR), and sludge discharge (SD)) were simulated by GPS-X software (Hydromantics 8.0.1). It was shown that ECR has the greatest impact on optimization objectives. In the optimal scenario, the main parameters of ATDO, MTDO, IRR, and ERR were 0.1 mg/L, 4 mg/L, 50%, and 100%, respectively. The EQI, OCI, and GHG of the best scenario were 0.046 kg/m3, 0.27 ¥/m3, and 0.51 kgCO2/m3, which were 2.1%, 72.2%, and 34.6% better than the current situation of the case WWTP, respectively. This study provides an effective method for realizing low-carbon and economical operation of WWTPs.

Polyaluminum chloride (PAC) modification of dispersive soil: A comprehensive study on dispersivity, mechanical properties, and microscale mechanisms

The engineering problems caused by dispersive soil are of worldwide concern. Traditional high carbon emission soil amendments such as cement and lime cause several environmental problems, including pollution and soil alkalization. Inorganic polymers are considered to be an economical, effective, and environmentally friendly soil amendment. Therefore, this paper proposes the use of the polymeric coagulant polyaluminum chloride (PAC) to improve soil dispersivity. PAC was added to the dispersive soils at different dry mass ratios of 0%, 0.5%, 1%, 1.5%, 2.5%, 4%, 5%, 6%, 7%, 8%, and 10%. The soil samples were then cured for 1, 4, 7, 14, and 28 days. Soil dispersivity was determined by crumb tests, pinhole tests, and exchangeable sodium ion percentage tests. Soil mechanical strength was assessed through unconfined compressive strength tests and unconsolidated undrained triaxial tests. Particle size distribution, pH, resistivity, X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy tests were conducted to investigate soil improvement mechanisms. Experimental results indicate that 1.5% PAC can transform highly dispersive soil into non-dispersive soil after 1 day of curing. When the PAC content increases from 0% to 7%, the unconfined compressive strength of the soil increases by 110.1%, and the internal friction angle and cohesion increase by 61.1% and 24.2%, respectively. The changes in the physicochemical properties and microstructure of the soil indicate the high-valence cations produced by PAC hydrolysis can effectively replace Na+ in the soil, while significantly reducing the pH value of the soil. Simultaneously, the coagulation effect generated markedly reduces soil porosity, resulting in a more compact soil structure. In summary, PAC demonstrates excellent potential in improving soil dispersivity and mechanical properties. Compared to traditional high carbon emission amendments such as cement and lime, PAC can effectively reduce soil alkalinity, mitigate environmental issues associated with these materials, and offer new possibilities for improving dispersive soils.

Anaerobic membrane bioreactor coupled with polyaluminum chloride for high-strength phenolic wastewater treatment: Robust performance and potential mechanisms

Anaerobic digestion of phenolic wastewater by anaerobic membrane bioreactor (AnMBR) has revealed increasing attractiveness, but the application of AnMBRs for treating high-strength phenolic wastewater faces challenges related to elevated phenol stress and membrane fouling. In this study, the coupling of AnMBR and polyaluminum chloride (PAC) was developed for efficient treatment of high-strength phenolic wastewater. The system achieved robust removal efficiencies of phenol (99%) and quinoline (98%) at a gradual increase of phenol concentration from 1000 to 5000 mg/L and a constant quinoline concentration of 100 mg/L. The dosing of PAC could effectively control the membrane fouling rate with the transmembrane pressure (TMP) increasing rate as low as 0.17 kPa/d. The robust performances were mainly attributed to the favorable retention of functional microbes through membrane interception, while pulse cross flow buffered against phenol stress and facilitated cake layer removal. Meanwhile, the enriched core functional microbes, such as Syntrophorhabdus, Syntrophus, Mesotoga and Methanolinea, played a crucial role in further reduction of phenol stress. Notably, the significant presence of biomacromolecule degrader, such as Levilinea, contributed to membrane fouling mitigation through extracellular polymer degradation. Moreover, the enlargement of particle size distribution (PSD) by PAC was expected to mitigate membrane fouling. This study provided a promising avenue for sustainable treatment of high-strength phenolic wastewater.

Separated or Combined Treatment of Dye Wastewater Streams: A Case Study with Coagulation and Flocculation Process

This study compared the treatment conditions and efficiencies of the coagulation and flocculation process (CFP) on mixed and separated dye wastewater. The CFP, which employed Poly Aluminium Chloride (PAC) as coagulant and mucilage extracted from the peel of dragon fruit (Hylocereus undatus) (DFPM) as flocculant, was investigated based on Jar-tests. The suitable coagulation and flocculation conditions were found similar at pH (4-7), settling time (30-60 min.), and flocculant dosage (2-5 mg/L) for both type of wastewaters. However, the optimal PAC dosage was determined to be significantly higher for separated dye wastewater stream (330 mg/L PAC) than for the mixed one (260 mg/L PAC) to ensure same treatment efficiencies. The treatment efficiencies were similar for TSS and turbidity of both wastewater types; However, much less for color and COD of separated dye wastewater stream in comparison to those of the mixed one (78% and 68% vs 90% and 76%, respectively). This study provides a scientific basis for the consideration of separated or combined treatment of dye wastewater streams by CFP.
 
 

Combination of membrane bioreactor with chemical coagulation for the treatment of real pharmaceutical wastewater: Comparison of simultaneous and consecutive pre-treatment of coagulation on MBR performance

In this work, the combination of the coagulation process with the MBR system to reclaim effluent in pharmaceutical industries was investigated. In this research, comparison/concentration optimization of two modes of integrations, including simultaneous; one-step one pot, and consecutive coagulation MBR were investigated. Results showed that COD removal in simultaneous and consecutive modes at optimum values were 85 % and 95.8 %, respectively, which were considerably higher than that of control MBR; 53.89 %. The total fouling ratio for control MBR, simultaneous, and consecutive modes at optimum conditions were 70.69 %, 37.3 %, and 42.5 %, respectively, confirming that the integrated coagulation process and MBR system were considerably effective. Analyzing the secreted metabolite, e.g. protein, carbohydrate, and LB/TB-EPS ratio in the MBR tank as well as on the membrane surface showed that the charge-neutralization and entrapment of bio-foulants by aggregated clots during the coagulation hinder the adhesion of the biofouling agents on the membrane surface, therefore in-line with the flux attenuation trend, lower metabolite concentration results in less membrane fouling. It was found that simultaneous coagulative MBR with 100 mg/L FeCl3 concentration demonstrates better fouling mitigation in comparison with consecutive (even with poly aluminum chloride; PACl as coagulant aid) MBR, while the latter mode shows better performance in terms of wastewater treatment. These findings open avenues for future techno-economic assessments of a coagulation-assisted MBR, providing a cost-effective solution for treating high-strength wastewater on a larger scale.

Algae removal and algal organic matter chemistry modulated by KMnO4-PAC in simulated karst water

In this study, we examined the modulation of algae removal and algal organic matter (AOM) chemistry by potassium permanganate and poly-aluminum chloride (KMnO4-PAC) in simulated karst water. Specifically, we verified the compositional changes of AOM sourcing from Chlorella sp. and Pseudanabaena sp. in response to the presence of divalent ions (Ca2+ and Mg2+). Aromatic protein and soluble microbial products were identified as the primary AOM components. Divalent ions accelerated dissolved organic carbon (DOC) and UV254 removal, particularly with Pseudanabaena sp. greater than Chlorella sp. (P < 0.05). Surface morphology analysis manifested that the removal of filamentous Pseudanabaena sp. was more feasible in comparison to globular Chlorella sp.. Our results highlight the significance of divalent ions in governing chemical behaviors and subsequent removal of both algae and AOM. This study upscales the understanding of the interactions among divalent ions, algae and AOM during preoxidation and coagulation process in algae-laden karst water.

COAGULANT PREPARATION FROM GLUTARALDEHYDE-CROSSLINKED DURIAN SKIN CELLULOSE FOR TREATMENT OF WASTEWATER GENERATED BY SUGAR PALM STARCH INDUSTRIES

Arenga pinnata starch (APS) production from APS industrial centers in Klaten, Indonesia, produces Arenga pinnata starch mill effluent (APSME). This waste will undoubtedly harm the environment, significantly reducing river water quality. On the other hand, in Gunungpati, Semarang, Indonesia, durian fruit is abundant, it leaves durian skin waste, which may cause environmental pollution. However, durian skin contains cellulose, which has the potential to be valorized for various applications. Therefore, this study evaluated the preparation of natural coagulant from durian skin cellulose crosslinked with glutaraldehyde for treating APSME from APS industrial centers in Klaten, Indonesia. Durian skin flour (DSF), durian skin cellulose (DSC), and glutaraldehyde-crosslinked durian skin cellulose (DSC-G) coagulants were characterized by proximate composition, UV-Vis spectroscopy, Fourier-transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The effects of coagulant dose, pH, and mixing speed on removal efficiency and sludge volume in DSF, DSC, and DSC-G were compared with polyaluminum chloride (PAC). The study assessed the process efficiency in terms of percentage removals for chemical oxygen demand (COD), biological oxygen demand (BOD5), total dissolved solids (TDS), and total suspended solids (TSS) as 71.38%, 78.23%, 94.79%, and 96.12%, respectively, with a percentage sludge volume of 24%. The results indicated that the optimum DSC-G dosage was 2500 mg/L with an optimum working area of pH at 5.5 and a mixing speed of 90 rpm. DCS-G has a floc stability of -12.33 mV. This study indicated that DSC-G has the potential to be used as a coagulant for the treatment of APSME.

Enhanced Pretreatment of Natural Rubber Industrial Wastewater Using Magnetic Seed Coagulation with Ca(OH)2

The efficiency of magnetic seed coagulation (MSC) with pH adjustment by NaOH and Ca(OH)2 as a pretreatment for high-strength natural rubber industrial wastewater (NRIWW) was compared in this study. The high content of suspended solids (SSs) and other inhibitory substances of NRIWW is a primary issue which affects its subsequent secondary and tertiary treatment processes. The MSC process with polyaluminum chloride (PAC), anionic polymer (polyacrylamide—PAM)), and magnetic seeds (MS) (ferric oxide (Fe3O4)) was proven to be a cost-effective pretreatment of NRIWW, and Ca(OH)2 showed improved pretreatment performance, with turbidity, COD, and TSS removals of 95%, 56%, and 64%, respectively. Sedimentation was enhanced from 30 min by conventional coagulation to less than 5 min by the MSC. The organic components of NRIWW reacted with MS to generate Fe–OH/Fe–OH+ linkages through processes of surface complexing and hydrogen bonding. According to fractal analysis, the MSC process optimized with Ca(OH)2 produces less complex flocs that are uniform and densely packed. Additionally, MS served as an adsorbent and promoted the development of magnetic flocs by boosting their density and size. MSC with pH adjustment by Ca(OH)2 presents a robust and cost-effective pretreatment process for NRIWW.

Mechanistic insights into chemical conditioning on transformation of dissolved organic matter and plant biostimulants production during sludge aerobic composting

Inorganic coagulants (aluminum and iron salt) are widely used to improve sludge dewaterability, resulting in numerous residues in dewatered sludge. Composting refers to the controlled microbial process that converts organic wastes into fertilizer, and coagulant residues in dewatered sludge can affect subsequent compost efficiency and resource recycling, which remains unclear. This work investigated the effects of two typical metal salt coagulants (poly aluminum chloride [PAC] and poly ferric sulfate [PFS]) conditioning on sludge compost. Our results revealed that PAC conditioning inhibited composting with decreased peak temperature, microbial richness, enzymatic reaction intensities, and compost quality, associated with decreased pH and microbial toxicity of aluminum. Nevertheless, PFS conditioning selectively enriched Pseudoxanthomonas sp. and resulted in more fertile compost with increased peak temperature, enzymatic reaction intensities, and humification degree. Spectroscopy and mass difference analyses indicated that PFS conditioning enhanced reaction intensities of labile biopolymers at the thermophilic stage, mainly comprising hydrolyzation (H2O), dehydrogenation (-H2, -H4), oxidation (+O1H2), and other reactions (i.e., +CH2, C2H4O1, C2H6O1). Unlike the common composting process primarily conducts humification at the cooling stage, PFS conditioning changed the main occurrence stage to the thermophilic stage. Non-targeted metabolomics revealed that indole (a humification intermediate) is responsible for the increased humification degree and indoleacetic acid content in the PFS-conditioned compost, which then promoted compost quality. Plant growth experiments further confirmed that the dissolved organic matter (DOM) in PFS-conditioned compost produced the maximum plant biomass. This study provided molecular-level evidence that PFS conditioning can promote humification and compost fertility during sludge composting, enabling chemical conditioning optimization for sustainable management of sludge.

The impact of recycling polyaluminium chloride and anionic polyacrylamide water treatment residuals on heavy metal adsorption in soils: implications for stormwater bioretention systems.

Despite the high adsorption capacity of polyaluminum chloride and anionic polyacrylamide water treatment residuals (PAC-APAM WTRs) for Pb2+, Cd2+, Cu2+, and Zn2+, their influence on the adsorption behavior of heavy metals in traditional bioretention soil media remains unclear. This study investigated the impact of PAC-APAM WTRs at a 20% weight ratio on the adsorption removal of Pb2+, Cd2+, Cu2+, and Zn2+ in three types of soils. The results demonstrated improved heavy metal adsorption in the presence of PAC-APAM WTRs, with enhanced removal observed at higher pH levels and temperatures. The addition of PAC-APAM WTRs augmented the maximum adsorption capacity for Pb2+ (from 0.98 to 3.98%), Cd2+ (from 0.52 to 10.99%), Cu2+ (from 3.69 to 36.79%), and Zn2+ (from 2.63 to 13.46%). The Langmuir model better described the data in soils with and without PAC-APAM WTRs. The pseudo-second-order model more accurately described the adsorption process, revealing an irreversible chemical process, although qe demonstrated improvement with the addition of PAC-APAM WTRs. This study affirms the potential of PAC-APAM WTRs as an amendment for mitigating heavy metal pollution in stormwater bioretention systems. Further exploration of the engineering application of PAC-APAM WTRs, particularly in field conditions for the removal of dissolved heavy metals, is recommended.

Enhancing water–wastewater treatment efficiency: synergistic approach using polyaluminum chloride, sodium alginate, and magnetite for Congo red removal

Enhancing water–wastewater treatment efficiency: synergistic approach using polyaluminum chloride, sodium alginate, and magnetite for Congo red removal

A New Method for Quantifying Aluminum in Antiperspirant Lotion Using a Differential Refractometer and an HPLC Column Containing a Maleate Functional Group Kumarswamy Ummiti1*, Narayana Reddy Godi2 , Hanimi Reddy Bapatu2

Aluminum chlorohydrate is a chemical substance employed as an agent to reduce perspiration. As an active antiperspirant agent, it is present in over-the-counter hygiene products at a concentration of up to 25%. The concentration of aluminum chrohydrate will be estimated indirectly by measuring the concentration of free aluminum ions. Various methodological approaches, including atomic absorption spectroscopy, ion chromatography, and titration, can be employed for the estimation of aluminum. In this study, a novel reverse-phase isocratic liquid chromatography approach was created. The method utilized a differential refractometer, a column packed with a maleate group, and an eluent consisting of 2.0% v/v formic acid. The suggested methodology demonstrates a high degree of precision in quantifying the presence of aluminum in Aldry lotion. According to studies testing accuracy, linearity, and precision, the disclosed analytical technique for quantifying aluminum has a range of 0.125 mg/mL to 0.375 mg/mL. The proposed methodology has a significantly reduced execution time of 10 minutes and is characterized by its cost-effectiveness.

Mesocosm study of PAC-modified clay effects on Karenia brevis cells and toxins, chemical dynamics, and benthic invertebrate physiology

Modified clay compounds are used globally as a method of controlling harmful algal blooms, and their use is currently under consideration to control Karenia brevis blooms in Florida, USA. In 1400 L mesocosm tanks, chemical dynamics and lethal and sublethal impacts of MC II, a polyaluminum chloride (PAC)-modified kaolinite clay, were evaluated over 72 h on a benthic community representative of Sarasota Bay, which included blue crab (Callinectes sapidus), sea urchin (Lytechinus variegatus), and hard clam (Mercenaria campechiensis). In this experiment, MC II was dosed at 0.2 g L-1 to treat bloom-level densities of K. brevis at 1 × 106 cells L-1. Cell removal in MC II-treated tanks was 57% after 8 h and 95% after 48 h. In the water column, brevetoxin analogs BTx-1 and BTx-2 were found to be significantly higher in untreated tanks at 24 and 48 h, while in MC II-treated tanks, BTx-3 was found to be higher at 48 h and BTx-B5 was found to be higher at 24 and 48 h. In MC II floc, we found no significant differences in BTx-1 or BTx-2 between treatments for any time point, while BTx-3 was found to be significantly higher in the MC II-treated tanks at 48 and 72 h, and BTx-B5 was higher in MC II-treated tanks at 24 and 72 h. Among various chemical dynamics observed, it was notable that dissolved phosphorus was consistently significantly lower in MC II tanks after 2 h, and that turbidity in MC II tanks returned to control levels 48 h after treatment. Dissolved inorganic carbon and total seawater alkalinity were significantly reduced in MC II tanks, and partial pressure of CO2 (pCO2) was significantly higher in the MC II-only treatment after 2 h. In MC II floc, particulate phosphorus was found to be significantly higher in MC II tanks after 24 h. In animals, lethal and sublethal responses to MC II-treated K. brevis did not differ from untreated K. brevis for either of our three species at any time point, suggesting MC II treatment at this dosage has negligible impacts to these species within 72 h of exposure. These results appear promising in terms of the environmental safety of MC II as a potential bloom control option, and we recommend scaling up MC II experiments to field trials in order to gain deeper understanding of MC II performance and dynamics in natural waters.

Investigating the improvement of the quality of industrial effluents for reuse with added processes: coagulation, flocculation, multi-layer filter and UV

Reuse of wastewater is one of the ways to develop water resources. In addition to the need for drinking water, many industries also need high-quality water in the production line. Therefore, the purpose of the present study is to investigate the advanced treatment of the wastewater treatment plant of Morche Khort industrial town using the processes of coagulation, flocculation with aeration, multi-layer filter, and disinfection by ultraviolet radiation to increase the quality of wastewater and reuse it in industries. In this study, to investigate the effect of coagulation and flocculation units along with aeration, filtration, and disinfection by ultraviolet rays (UV), on the quality of the secondary effluent from the wastewater treatment plant of Morche Khort industrial town, they were operated on a pilot scale. Polyaluminum chloride (PAC) was used as a coagulant. Layering of three layers of sand filter, from bottom to top including granulated silica at a height of 10 cm, sand at a height of 20 cm, and activated carbon at a height of 70 cm was used. The input and output sampling points of each unit were considered. By repeating twice in five stages of flow rates of 1, 2, 4, 6, and 8 (L/min), the samples were collected to determine COD, TSS, TDS, turbidity, pH, hardness, total coliform, and fecal coliform. Jar test results showed that Alum coagulant works almost the same as PAC in removing turbidity, but the efficiency of removing organic substances by PAC coagulant is higher than that of Alum at lower doses. The results of this study showed that the efficiency of the coagulation and flocculation process in removing turbidity, COD, TSS, TDS, and fat was 56.88%, 46.66%, 38%, 23.19%, and 91.43% respectively. In the current study, the results of the wastewater entering the sand filter showed that the percentage of removal efficiency with a loading rate of 1 (L/min) was turbidity, TSS, COD, TDS, and fat was 16. 93%, 56.84%, 50%, 5.67%, 33.44% respectively. In the UV disinfection unit, the removal efficiency percentage with a loading rate of 1 (L/min) for COD, TSS, turbidity, hardness, total coliform, and fecal coliform is 16%, 3.45%, 3.58%, 5.21%, 99.88%, and 98.37% respectively. Coagulation and flocculation system—multi-layer filter and disinfection can remove chemical–physical and microbial parameters to an acceptable level for using water in advanced purification systems and also for irrigation.

Assessing the efficacy of polyaluminium chlorides in improving pool water quality using impedance spectroscopy

This paper describes an experimental study on the effects of polyaluminium chloride (PAC) on pH, turbidity, and electrical properties of pool water. Our results demonstrates that as the concentration of PAC increases, pH decreases until a concentration of 2.5 mg/L, suggesting an acidic effect of the flocculant. Thus, the turbidity decreases with increasing PAC concentration up to 2.5 mg/L, indicating effective particle clumping and settling. Beyond this concentration, turbidity starts to increase, possibly due to excessive flocculant dosage or unintended reactions. Impedance spectroscopy is used to analyze the electrical properties of the treated water. The Nyquist and Bode plots reveal two relaxation processes and changes in conductivity. The optimal PAC concentration for treating pool water is found to be 2.5 mg/L, where suspended particles are effectively removed while maintaining suitable conductivity. Also, an equivalent circuit is devlopped to model the electrical behavior, and its simulation closely matches experimental data. The relaxation times and DC conductivity are influenced by the PAC concentration, with different behaviors observed below and above 2.5 mg/L. Below this concentration, PAC neutralizes particles, while above it, excess PAC content leads to increases in these parameters.

Exploring source water mixing strategies to reduce chemical consumption and environmental footprint in surface water treatment

Abstract Common methods for treating surface waters involve chemical flocculation, for which a significant factor contributing to the total cost and climate impact is the consumption of chemicals, chiefly coagulants and pH-adjusting chemicals. The amount of chemicals required for treating surface waters and achieving suitable flocculation pH depends greatly on the alkalinity of the source water. This study investigates the viability of mixing two surface waters with different chemical properties with the aim of reducing the amount of chemicals used during chemical flocculation. Bench-scale experiments were carried out, and the results were compared with full-scale operations at a surface water treatment plant (WTP). The WTP uses ferric chloride as a coagulant, which effectively removes natural organic matter, but consumes large amounts of hydroxide to manage pH before and after flocculation. As an alternative process, this study tested the use of aluminum sulfate, polyaluminum chloride and ferric chloride at varying dosages in combination with different source water mixtures to achieve suitable flocculation pH. The results showed that pH-adjusting chemicals could be omitted by adding a small amount of high alkalinity surface water to the primary source water, thereby reducing costs and climate impact substantially.

Coagulation/Floculation Of Slaughter Effluent Using Moringa Oleifera Lam as A Coagulant

Objective: In view of the growing need for low-cost, easily accessible alternative wastewater treatments, this study aimed to evaluate the influence of a natural product (Moringa oleifera lam), when used as a coagulant, on the removal of turbidity and color from a pig slaughterhouse effluent. Method/design/approach: The coagulant was prepared in saline solution (NaCl - 1M) and saline solution (KCl - 1M), all the coagulant solutions were prepared at the time of the test. In order to assess the effect of the coagulant on the effluent, coagulation/flocculation tests were carried out using the Jar- test apparatus, evaluating the effects of dosages of 200, 500, 1000, 1500 and 2000 mg/L of Moringa in saline solution (NaCl and KCl). The parameters analyzed were color and turbidity. Results and conclusion: According to the results of the statistical analysis, the optimum dosages obtained for the coagulants Moringa NaCl and Moringa KCl were 1000 and 1500 mg/L, respectively. With these dosages, removal of 63.9% for turbidity and 56.3% for color was observed when using NaCl saline solution and removal of 57.4% for turbidity and 45.2% for color when using the coagulant in KCl saline solution. Implications of the research: The main implication of the study is a proposal to evaluate the efficiency of the coagulation/flocculation/decantation process of pig slaughterhouse effluent, using natural coagulants, in the removal of organic matter. Due to the many problems caused by the use of chemical coagulants, such as aluminum sulfate and aluminum polychloride, which are used worldwide, there is a great demand for an alternative coagulant that is mainly natural. Originality/value: The study seeks to contribute to improving the management of water resources, in terms of local management. The use of natural coagulants, produced locally and at a low cost, can alleviate the problems linked to the discharge of untreated wastewater into receiving water bodies and the consumption of non-potable water.

Coagulation/Flocculation of Slaughterhouse Effluent Using Pac and Tanfloc as Coagulants

Objective: In this context, this research aimed to evaluate the influence of different types of coagulants, one inorganic and one natural (PAC and Tanfloc), in the treatment of an effluent from a pig slaughterhouse. Method/design/approach: Both coagulants were prepared in aqueous solution at the time of the test, 1% (v/v) for PAC and 0.5% (m/v) for Tanfloc. To assess the effect of the coagulants on the effluent, coagulation/flocculation tests were carried out using the jar-test apparatus. The dosages evaluated for both coagulants were 50, 100, 150, 200, 250 and 300 mg/L. The parameters analyzed were color and turbidity. Results and conclusion: According to the results of the statistical analysis, the optimum dosages obtained for both coagulants was 250 mg/L. With these dosages, removal of the parameters analyzed was observed (&gt; 94% for turbidity and &gt; 85% for color) with residuals (&lt; 40 NTU for turbidity and &lt; 400 uH for color), showing better results at this optimum dosage when Tanfloc is used as a coagulant. Implications of the research: The growing awareness that effluent treatment is of fundamental importance to public health and environmental pollution control has led us to look for low-cost alternatives to treat these effluents, using a vegetable organic coagulant based on tannin as an alternative to aluminum polychloride (PAC). Originality/value: Due to the growing need for low-cost, easily accessible treatments that do not require large areas, physical-chemical treatment of slaughterhouse effluent can be used as a pre-treatment, with the use of alternative coagulants, being a viable way to reduce organic matter for subsequent biological treatment, or in some cases replace the biological process.