Polyaluminum Chloride Dosage Research Articles

Mathematical Modeling and Indirect Carbon Emission Reduction Analysis of Urban Wastewater Treatment Systems Under Different Temperature Conditions

In the context of achieving the two-carbon target, this study utilized a wastewater treatment plant in Shenyang City as a case study to accurately calculate indirect emissions related to energy and chemical consumption within the energy-intensive wastewater treatment industry. Sumo software was employed for precise mathematical modeling. Considering the operational characteristics of wastewater treatment plants in cold regions, this study innovatively divided the annual operation cycle into two periods, namely normal temperature and low temperature, and determined the optimal operational parameters under a low-carbon mode. The results indicate that precise regulation of dissolved oxygen concentration to 0.5–1.5 mg/L (normal temperature period) and 1–2 mg/L (low temperature period) can significantly reduce carbon emissions related to electricity consumption by 13,781.9 t CO2-eq. From the perspective of chemical consumption, adjusting the dosage of polyaluminum chloride (PAC) to 75% and sodium acetate to 70% during the normal temperature period can lead to a reduction in indirect carbon emissions of 1614.4 t CO2-eq compared to the same period last year. During the low-temperature period, by reducing the dosage of polyaluminum chloride to 80% and sodium acetate to 75%, the indirect carbon emissions can be reduced by 1557.3 t CO2-eq compared to the corresponding period last year. After optimization, USD 1.49 million can be saved. This study simulated the operation conditions of cold-region urban wastewater treatment plants at different times to effectively control carbon emissions resulting from energy and chemical consumption in wastewater treatment. This result can provide innovative ideas for energy saving and carbon reduction in cold-region wastewater treatment plants.

Experimental study on the treatment of high COD metal degreasing cleaning wastewater by coagulation and two-stage Fenton oxidation

ABSTRACT In this study, based on the water quality characteristics of metal degreasing cleaning wastewater, wastewater treatment by coagulation combined with two-stage Fenton oxidation was proposed. The results showed that when the dosage of polyaluminium chloride (PAC) was 5 g/L and the dosage of cationic polyacrylamide (CPAM) was 8 mg/L, with an initial pH of 8, rapid stirring at 350 rpm for 3 min followed by slow stirring at 200 rpm for 15 min, the optimal removal rate of chemical oxygen demand (COD) in metal degreasing cleaning wastewater reached 74.08%. Primary Fenton oxidation is mainly aimed at decomposing macromolecular long-chain pollutants and removing some pollutants. The highest COD removal rate was achieved at 95.07% when the dosage of H2O2 was 4 mol/L, the dosage of FeSO4 was 40 g/L, the oxidation lasted for 60 min, the initial pH was 2, the effluent pH was 8, and the settling time was 90 min. The two-stage Fenton oxidation process provided further advanced treatment. With a reagent ratio of 1:0.5, the effluent COD concentration was reduced to 457 mg/L, meeting the third-class standard of the ‘Integrated Wastewater Discharge Standard’ (GB 8978 − 1996).

Experimental study on surface optimization of dosage in magnetic coagulation process for enhancing primary treatment of urban sewage

This work aims to investigate the minimum dosage required to achieve optimal removal of carbon, nitrogen, and phosphorus in the Chemical Enhanced Primary Treatment (CEPT) process using magnetic coagulation technology. A response surface methodology was adopted to generate multiple regression models to optimize the dosages of three types of coagulation, i.e., polyaluminum chloride (PAC), polyacrylamide (PAM), and magnetic medium Fe3O4 particles (MP), based on the removal rates of chemical oxygen demand (COD), ammonia nitrogen (NH3-N), and total phosphorus (TP). The results showed that the regression models could predict results well with actual engineering results. Compared to the traditional coagulation process, the synergistic enhancement of PAC+PAM+MP in the CEPT process significantly improved the treatment effects. Based on the COD removal rates, PAC performed better than MP, followed by PAM; likewise, for the NH3-N and TP removal rates, PAC outperformed PAM, followed by MP. The optimized PAC, PAM, and MP dosages were 135.87, 1.51, and 108.36 mg/L, respectively, reaching 92.27 % COD, 71.98 % NH3-N, and 91.33 % TP removal rates with less than 5 % errors compared to the experimental verification results. These optimization models offer a practical and cost-saving reference for enhancing the primary treatment effect on carbon, nitrogen, and phosphorus removal using PAC+PAM+MP.

Interface dynamics in dewatering processes of high-water-content slurry flocculated with PAC

This study addresses the challenge of the reverse effect observed in the dewatering process of waste slurry as poly-aluminum chloride (PAC) dosages increase. It investigates the flocculation mechanism of PAC at varying dosages in a high-water-content slurry using molecular dynamics simulation methods. The results indicate that PAC molecules primarily adsorb montmorillonite particles while exerting negligible influence on quartz. Dewatering efficiency is influenced by the adsorption-repulsion interaction at the PAC-montmorillonite interface. Efficiency increases with PAC dosage up to an optimum level due to enhanced adsorption but decreases thereafter due to increasing repulsion. Within this optimal range, montmorillonite interfaces exhibit a higher negative charge, facilitating stable PAC adsorption and leading to increased aggregation of montmorillonite particles, thereby forming flocs. The adsorption capacity of PAC on montmorillonite particles escalates with dosage until achieving the optimal flocculation effect. However, surpassing this optimal dosage prompts repulsion among outer PAC molecules, gradually causing montmorillonite particles to separate due to repulsion, thereby weakening the flocculation effect. This research provides theoretical support for the flocculation and dewatering of PAC in high-water-content waste slurry, emphasizing the rational and cost-effective addition of PAC in practical applications.

Evaluation of turbidity removal efficiency from Karun river water using polyaluminum chloride and chitosan

This study was conducted with the aim of evaluation of turbidity removal efficiency from Karun river water using polyaluminum chloride and chitosan. Chitosan is a linear cationic polyelectrolyte with high positive electron charge (one positive charge per glucose amine unit). Chitosan is used in water purification systems as coagulant along with common coagulants (alum, chlorferric). This biopolymer is also used as a primary coagulant. Chitosan has a higher ability to coagulate colloidal particles than synthetic polyelectrolytes, most of which lack the property of biological degradation in the short term, and some of them cause carcinogenesis and genetic mutation in humans. Therefore, the use of chitosan is preferable to artificial polyelectrolytes from an environmental point of view. This research was conducted on the laboratory scale using a jar test device at the water treatment plant in Ahvaz. In this study, various parameters such as pH, polyaluminum chloride concentration and chitosan concentration were present as variables. After preparing the samples and just before starting jar tests, in the rapid mixing cycle of 200 rounds per minute, the optimal pH to remove the turbidity obtained 8. Also, the optimal dosages of polyaluminum chloride and chitosan were selected as 4 ppm and 0.04 ppm, respectively. Also the main mechanism for destabilizing clots and removing turbidity was bridging between the particles. In this condition, the removal of turbidity showed the highest efficiency. On the other hand, chitosan created clots with a higher weight and, as a result, better settling ability. Therefore, chitosan was a suitable choice to remove turbidity from water.

A systematic investigation of peracetic acid oxidation and polymeric coagulants re-flocculation to enhance activated sludge dewatering: Multi-porous skeleton structures

In this research, the effects of peracetic acid (PAA), polymeric flocculants, and their combined conditioning on improving the dewatering performance were comprehensively evaluated. The results showed that sludge cake moisture content, capillary suction time (CST), and specific resistance to filtration (SRF) were 70.6%, 48.1 s, and 3.42 × 1012 m/kg after adding 0.10 g/gMLSS PAA for 50 min, representing reductions of 12.60%, 40.32%, and 33.98%, respectively. Additionally, conditioning of sludge with polyferric sulfate (PFS), polyaluminum chloride (PAC), and cationic polyacrylamide (CPAM) enhanced sludge properties in the following order: CPAM > PAC > PFS. After the PAA oxidation and re-flocculation process, the optimal dosages of PFS, PAC, and CPAM were reduced to 1.5 g/L, 0.9 g/L, and 0.04 g/L, respectively. The sludge dewatering performance significantly improved, with sludge cake moisture content measuring 65.8%, 66.3%, and 61.7%, respectively. Moreover, the spatial multi-porous skeleton structures were formed via re-flocculation to improve the sludge dewatering. Furthermore, economic evaluation validated that the pre-oxidation and re-flocculation process could be considered an economically viable option. These research findings could serve as a valuable reference for practical engineering applications.

Optimization of turbidity removal and floc formation for ballasted flocculation using magnetite-based agents by response surface methodology

In this study, a static mixer was used as an alternative to the existing flash mixing method for ballasted flocculation to assess the turbidity removal and ballasted floc formation characteristics. Synthetic magnetite exhibits excellent properties, such as high specific gravity, hydrophobicity, and wear resistance, making it a suitable ballast agent (BA). The experimental design was optimized using the response surface methodology. To evaluate turbidity removal, a model based on polyaluminum chloride dosage, BA surface charge, and pH was developed. To assess the ballasted floc characteristics, the BA dosage, BA size, and G value of the static mixer were used. During ballasted flocculation, the impact of the zeta potential of the BA was minimal. Consequently, bonding primarily resulted from the viscosity of the floc caused by physical collisions rather than electrostatic forces stemming from the BA charge. The findings of this study demonstrated promising outcomes, including potential energy savings and process streamlining, by identifying crucial design elements for implementing a static mixer in the ballasted flocculation process.

Highly efficient phosphorus removal by a novel prolonged stirring pelleting coagulation for sludge water treatment

Sludge water with high total phosphorus (TP) and suspended solids (SS) easily causes the effluent quality to be substandard in wastewater treatment plants. Although the conventional coagulation process can achieve TP removal, higher sludge production occurred due to loose flocs generation. The prolonged stirring pelleting coagulation (PSPC) process, based on one-by-one agglomeration and mechanical syneresis theories, was proposed to achieve compact flocs and reduced sludge production. Compared with the conventional coagulation process, the removal efficiency of TP was improved by >20 %, settling volume was reduced by about 30 %, and the dosages of polyaluminum chloride (PAC) and polyacrylamide (PAM) were saved by 50 % and 30 %, respectively in the PSPC process. The PSPC process produced pellet-like flocs with the d50 of 6.27 mm, settling velocity of 21.07 mm/s, effective density of 0.1411 g/cm3, and three-dimensional fractal dimension (D3) of 2.094 under the optimal conditions of 50 mg/L PAC and 10 mg/L PAM. With the d50 decreased from 38.38 μm to 21.81 μm, fragmentation of primary particles was realized by high-intensity stirring. Therefore, the mechanism of the PSPC process involves reducing voids in primary particles, achieving regular combination of microflocs under appropriate PAC, PAM, and hydraulic control. The PSPC process shows promising prospects for treating high SS wastewater and may have practical implications for enhancing coagulation.

Response Surface Methodology Approach to Optimize Parameters for Coagulation Process Using Polyaluminum Chloride (PAC)

Coagulation is a process affected by multiple variables, nonlinear mapping and multiple perturbations. In order to realize the precise dosage of flocculants, polyaluminum chloride (PAC) was taken as the research object to explore the effects of temperature, water turbidity, pH and CODMn on the dosage of PAC and coagulation effect. A response surface methodology (RSM) experiment was carried out based on a single-factor experiment. The turbidity, pH and dosage of a single parameter, as well as the interaction term and secondary term, all have significant influence on coagulation effect. The optimal reaction conditions were calculated using Design-Expert software: pH, 7.48; turbidity, 14.59 NTU; dosage, 24.01 mg/L; and the error between the experimental value and the predicted value, 4.08%. Establishing a model with residual turbidity as a consideration index can help to calculate the optimal dosage of PAC, which is conducive to a reasonable and accurate control of the dosage of PAC in the coagulation process, so as to achieve the goal of low turbidity of effluent and low production cost.

The removal of microplastics from reverse osmosis wastewater by coagulation

Wastewater treatment plants (WWTPs) are major sources of microplastic (MP) discharge into water bodies, leading to plastic pollution in the environment and negative effects on aquatic ecosystems. Research is increasingly being focused on MP removal from wastewater, as their presence in freshwater environments, and associated risks, are matters of growing concern. Eliminating MPs from wastewater is a significant challenge for WWTPs, and mitigation actions are required to develop and improve removal treatments. Coagulation has been shown to have high removal efficiency for suspended particles, including MPs. This process involves the addition of coagulants, such as aluminum or iron salts that together with the MPs form larger flocs, facilitating their removal by settling or flotation. Our study evaluated the coagulation process, aiming to improve MP removal from wastewater generated from reverse osmosis (RO) concentrate, backwash microfiltration (MF), and cleaning chemicals for membranes operated by MF and RO processes in industrial water supply facilities. More than 1000 MP particles, predominantly polymers with polyethylene (PE), polypropylene (PP), and polystyrene (PS) were identified as being influenced by the current process. We used polyaluminum chloride (PAC) as chemical coagulant to evaluate MP removal during batch experiments (jar test). Our coagulation process achieved higher efficiencies for microplastic removal than conventional biological treatment processes at an optimal PAC dose and pH. Remarkable results were obtained, with more than 90% of MPs being removed. Our findings indicate that chemical coagulation is effective for removing MPs, and that the process could be optimized by selecting an appropriate coagulant and pH.

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.
 
 

Field Approach on the Effectiveness of Hydraulic Flocculator Followed By Sedimentation and Rapid Sand Filter

This research investigates the effectiveness of a hydraulic flocculator at the Kalanki Groundwater Treatment Project-Sipradi in Kalanki-Kathmandu. Hydraulic flocculation is a cost-effective alternative to mechanical flocculation, particularly beneficial for developing nations. The study involved determining the optimal Poly Aluminium Chloride (PACl) dosage through Jar Testing and assessing the flocculator's efficiency in the field with this dose. The research also analyzed other treatment units under various PACl doses to evaluate the Water Treatment Plant's operational conditions and the required PACl dose for efficient turbidity removal. The system included components like a deep well source, V-Notch weir tank, hydraulic flocculator, sedimentation tank, rapid sand filter (RSF), chlorinator, and clear water reservoir, with a 16-minute flocculator detention time. Baffle walls were strategically positioned at various intervals on-site. The study revealed that while sedimentation with coagulation achieved peak efficiency at a PACl dose of 80mg/l, it was less efficient than a 16-minute jar detention, likely due to sedimentation tank short-circuiting. Increasing the PACl dose from 20 mg/l to 80 mg/l improved overall unit efficiency, indicating the need for more mixing energy in the existing flocculator length for optimal results. The filter unit's efficiency remained consistent, whether with or without coagulation, at 57.69% and 54.10%, respectively. These results emphasize the importance of further investigation to enhance water treatment processes and coagulant dosages for improved effectiveness in this critical field.

Experimental investigation of the inhibition of deep-sea mining sediment plumes by polyaluminum chloride

Deep-sea sediment disturbance may occur when collecting polymetallic nodules, resulting in the creation of plumes that could have a negative impact on the ecological environment. This study aims to investigate the potential solution of using polyaluminum chloride (PAC) in the water jet. The effects of PAC are examined through a self-designed simulation system for deep-sea polymetallic nodule collection and sediment samples from a potential deep-sea mining area. The experimental results showed that the optimal PAC dose was found to be 0.75 g/L. Compared with the test conditions without the addition of PAC, the presence of PAC leads to a reduction in volume, lower characteristic turbidity, smaller diffusion velocity, and shorter settling time of the plume. This indicates that PAC inhibits the entire development process of the plume. The addition of PAC leads to the flocculation of mm-sized particles, resulting in the formation of cm-sized flocs. The flocculation of particles decreases the rate of erosion on the seabed by around 30%. This reduction in erosion helps to decrease the formation of plumes. Additionally, when the size of suspended particles increases, it reduces the scale at which they diffuse. Furthermore, the settling velocity of flocs (around 10−2 m/s) is much higher that of compared to sediment particles (around 10−5 m/s), which effectively reduces the amount of time the plume remains in suspension.

Investigation of the treatment efficiency and mechanism of microporous flocculation magnetic fluidized bed (MFMFB) reactor for Pb(II)-containing wastewater

In this study, a novel microporous flocculation magnetic fluidized bed (MFMFB) reactor was proposed for the treatment of low concentration lead-polluted groundwater in Gansu Province, China. It introduced a magnetic levitation layer and non-coincident counterflow inlet by using flocculants of polyaluminum chloride (PAC) and polyacrylamide (PAM). And Particle Image Velocimetry (PIV) was used in conjunction with flocculation experiments. The results showed that when the dosage of poly PAC and PAM was 120 mg/L and 1 mg/L, respectively, at the same time the water inflow was 0.013–0.020 m3/h, the removal efficiency of Pb(II) and turbidity reached a steady level of over 98% in low turbidity and concentration Pb(II)-containing simulated wastewater. The reactor created favorable conditions for enhanced flocculation in terms of water flow direction, velocity gradient, effective energy consumption and microporous flocculation. Microporous flocculation form on the surface of the magnetic levitation layer, where fine particles contributed to both mixing and adsorption. The reactor possessed comprehensive flocculation effects such as anisotropy, micro-vortex, and microporous, and has the potential to treat low Pb(II)-containing groundwater.

Combined biological and chemical-physical processes for domestic wastewater treatment

The present study aims to investigate the possibility of domestic wastewater treatment using biological system combined with chemical-physical processes, including Upflow Sludge Blanket Filtration (USBF) technology and PolyAluminium Chloride (PAC). Experimental results showed that the added PAC content played an essential role in improving the treatment efficiency and reached National Technical Regulation on domestic wastewater QCVN 14:2008/BTNMT (Column A) for BOD5. With Jar-test results, the optimal pH of 7.0 and the PAC dosage of 170 mg/L were recorded with the highest removal efficiencies for suspended solids and organic matter. In the modified USBF bioreactor, the findings illustrated the pollutant removal efficiencies such as Biochemical Oxygen Demand (BOD5), Chemical Oxygen Demand (COD), and Suspended Solids (SS) were equal to 96.2 ± 1.4%, 85.8 ± 4.4% and 99.3 ± 2.1%, respectively. In the future, this USBF-based advanced technology has the potential to play a significant role in addressing water scarcity through wastewater reclamation and reuse.

EFEKTIVITAS KOMBINASI KOAGULAN SINTETIK DAN BIOKOAGULAN TERHADAP PENINGKATAN MUTU BAKU AIR SUNGAI TABALONG

Tabalong River is used as the raw water source for PDAM Tabalong. The large number of industrial activities in the district produces residual products that eventually pollute the watershed, resulting in a decrease in water quality and availability. Parameters that do not meet the standard quality standards as clean water based on Government Regulation No. 22 of 2021 class I are turbidity, color, TSS, dissolved Fe, dissolved Mn, and E. coli. This river water requires treatment with coagulation - flocculation technology with the jar test method. The technology requires a coagulant whose role is to precipitate colloidal particles. The commonly used coagulant is poly aluminum chloride (PAC). It is abundant but produces high concentrations of sludge, so coagulants that are biodegradable, biocompatible, non-toxic, and abundant are needed. These properties are found in biocoagulants in the form of chitosan. The coagulant in this study is synthetic (PAC) and bicoagulant (chitosan) by determining the optimum dose in river water treatment in the rainy season. The optimum dose is used to combine the ratio between coagulants. The ratio is (100:0, 25:75, 50:50, 75:25, and 0:100) which is analyzed for its effectiveness from each parameter. The optimum dose of PAC is 10 ppm and chitosan is 20 ppm. The best effectiveness is the PAC-chitosan combination in the form of a ratio of 0:100, which is in the form of chitosan which is able to reduce the levels of these parameters to meet the quality standards.

Synthesis of Polyaluminum Chloride Coagulant from Waste Aluminum Foil and Utilization in Petroleum Wastewater Treatment

This work investigates the potential synthesis of cost-effective polyaluminum chloride (PACl) coagulant from waste household aluminum foil and utilization for treating petroleum wastewater (PWW), especially dissolved organic compounds (DOC, like octanol–water mixture) and nonsettleable suspended (NSS-kaolin) mineral particles. Based on the Standard Practice for Coagulation–Flocculation Jar Test, the efficiency of PACl for DOC and NSS removal was evaluated in relation to the effects of the operational parameters. The results demonstrated that the as-prepared PACl has an amorphous morphology with a Keggin-type e-Al13 molecular structure {Na[AlO4(OH)24(H2O)]·xH2O and good thermal stability up to 278 °C. PACl coagulant also exhibited a higher efficiency for NSS removal than DOC by around 1.5- to 1.9-fold under broad pH (5–7), while a higher acidic/alkaline pH disrupts the sweep floc formation. An increased PACl dosage (over 25 mg/L) also caused a decrease in the coagulation efficiency by 11.7% due to Al species’ transformation and pH depression (from 6.8 to 4.9) via increased PACl hydrolysis. With a fast rotating speed of 280 rpm for 2 min, the minimum dose of PACl (10–25 mg/L) can maximize the removal efficiency of NSS (~98%) and DOC (~69%) at pH 6.5 ± 0.5 and 35 °C after 30 min of settling time. Treating actual saline PWW samples (salinity up to 187.7 g/L) also verified the high efficacy of PACl coagulation performance in reducing the turbidity and dissolved hydrocarbons by more than 75.5% and 67.7%, respectively. These findings verify the techno-economic feasibility of the as-prepared PACl coagulant in treating PWW treatment at different salinity levels.

A combined experimental-modeling approach for turbidity removal optimization in a coagulation–flocculation unit of a drinking water treatment plant

The drinking water treatment plant plays a key role in providing the consumers with a safe water, in compliance with the United Nations Sustainable Development Goal n. 6 (Clean water and sanitation). The typical drinking water treatment plant includes: coagulation–flocculation,​ sedimentation, filtration and disinfection. Turbidity removal is among the more common pollutants to remove; this goal is mainly achieved by the coagulation–flocculation process. The present paper shows the results of the application of a combined experimental-modeling approach for turbidity removal optimization in a coagulation–flocculation unit of a full-scale drinking water treatment plant. The applied approach consisted of a laboratory experimental activity aimed at determining the best coagulant type and dosage. Among the different chemicals tested, Poly aluminum chloride (PAC) provided the highest removal at the lowest dosage (90% at 3.5 mg/L PAC, 88% at 18.9 mg/L PACS and 77% at 30 mg/L FeCl 3). The addition of polyelectrolytes did not improve the removal at such a level to justify the consequent increase of the costs. Based on the findings of this phase of the study, a data-driven model was implemented using as input variables the historical data of influent and effluent turbidity and influent flow rate. Combining regression models and statistical analysis, it was possible to build up an algorithm for the case-study plant allowing to select the PAC dosage to apply as a function of the influent turbidity, to ensure the constant compliance with the regulation limit on effluent turbidity.

Oily wastewater treatment and reuse technology in low permeability oilfield

This paper takes Ordos Huaqing ultra-low permeability oilfield as the research object, analyzes the composition of the produced oily wastewater, and uses the treatment process of multiphase air flotation to shell filtration to quartz sand filtration to multi-effect evaporation to reuse the oily wastewater in the oilfield, analyzes the index changes of the purified oily wastewater. The results show that it has high oil content, salinity, sulfide, SS, sulfide and iron and manganese content. Through experimental combination and analysis of effluent quality, it is concluded that the process of multiphase air flotation→shell filtration→sand filtration→low temperature multi-effect evaporation is better, The average salinity of sewage in Huaqing oilfield used in the experiment is 2757 mg/L. and the dosage of polyaluminum chloride is 230 mg/L, polyacrylamide is 6 mg/L, the dissolved gas pressure of multiphase air flotation machine is 0.5 MPa, the reflux ratio of multiphase air flotation machine is 0.3, the dosage of defoamer is 5 mg/L, and the pH value is set at 5.5. The best treatment process of oilfield sewage and the best concentration of polyaluminum chloride and polyacrylamide are obtained. The research results provide theoretical data support for improving the treatment and reuse of oily wastewater in low permeability oilfield.

Prediction of the Optimal Dosage of Poly Aluminum Chloride for Coagulation in Drinking Water Treatment using Artificial Neural Networks

Drinking–water Treatment Plants (DWTP) dosing coagulant chemicals determines the success of water quality. The addition of these compounds is usually a manual procedure performed by trained people. This task is quite difficult because it requires a lot of experience for a correct dosage. To solve this problem, this study is based on the analysis of data collected from a raw water source located in Ecuador. Then, using the information on the physical-chemical parameters of the raw water, the definition of the doses of Polyaluminum Chloride (PAC), and the input and output variables of the dosage process are identified. Consequently, the implementation of an intelligent control system based on Artificial Neural Networks (ANN) is proposed. These experiments start with data collection and analysis in order to establish the variables involved in the process. The proposed neural model has three hidden layers, and it uses adaptive gradient algorithms. An analysis of the results was performed using Mean Absolute Percentage Error (MAPE) and Root Mean Square Error (RMSE). The PAC predictive model in the training phase gives a MAPE value of 0.0425 for the not adjusted values and 0.0262 for the adjusted numerical values. However, in the test phase the neural model achieves a MAPE of 0.057 for the not adjusted PAC values and 0.041 for the adjusted values. It can be concluded that this alternative provides an efficient solution when solving dosing problems in DWTPs, having reliable results from the RMSE and MAPE metrics.