Coagulant Dosage Research Articles

Effective removal of Rhodamine 6G (Basic Red-1) reactive dye using waxy corn starch in waste water of textile industry

The textile industry generates effluents containing toxic dyes, which have detrimental effects on the environment, including air, soil, and water contamination. These dyes also pose risks to human health and disrupt aquatic ecosystems. Developing ecological and cost-effective method to address this issue is a major challenge. This study focuses on utilizing waxy cornstarch, which exhibits unique properties such as high biodegradability, environmental compatibility, low sludge volume, small particle size, and high surface area (1.27 m2/g), for removing the reactive dye Rhodamine 6G (Basic Red-1) from textile wastewater. The composition of waxy cornstarch was analyzed, including determination of protein content using the Kjeldahl apparatus, as well as moisture content, ash content, and fine fiber content through experimental methods. The rate of dye removal from wastewater was assessed using a UV-spectrophotometer. The experimental design was selected, and trials were conducted using a glass testing apparatus. Dye removal rates were investigated at different dosages, temperatures, and pH ranges. The highest dye removal efficiency of 83.6% was achieved at a pH of 5, a temperature of 40 °C, and a coagulant dosage of 40 mg/l. These findings highlight the potential of waxy cornstarch as a natural coagulant for effective removal of Rhodamine 6G dye from textile wastewater.

Optimization use of watermelon rind in the coagulation-flocculation process by Box Behnken design for copper, zinc, and turbidity removal

Watermelon rinds were investigated as a bio-coagulant for treating water contaminated by metals and turbidity, owing to their biodegradability and greater environmental friendliness compared to chemical coagulants. Fourier transform infrared spectroscopy, scanning electron microscopy paired with energy dispersive X-ray analysis and X-ray diffraction characterized the watermelon rinds before and after use. A Box-Behnken experimental design optimized the most influential parameters of initial pH, coagulant dose, and particle size based on response surface methodology. This analysis revealed the experimental data fit quadratic polynomial models, achieving maximum removal efficiencies of 97.51 % for zinc, 99.88 % for copper, and 99.21 % for turbidity under optimal conditions. Statistical analysis confirmed the models effectively captured the experimental data. Analysis of variance denoted the high significance of the quadratic effects of dose and pH. Removal of metal ions Zn2+ and Cu2+ was significantly impacted by these factors. The watermelon rind powder retained its coagulation efficiency after five cycles of reuse, with removal rates of 80.04 % for Zn, 88.33 % for Cu and 86.24 % for turbidity. These results demonstrate the potential of watermelon rind as an alternative coagulant for wastewater treatment. Further testing on real industrial effluents at larger scales would help assess their feasibility for real-world applications.

Optimization of coagulation wastewater treatment of leather industry

The object of the study was the process of coagulation treatment of wastewater of leather industry enterprises. The treatment of samples of real wastewater from a leather production was investigated. Such wastewater is characterized by high concentrations of pollutants of varying degrees of dispersion, which is due to the use of a large number of various chemicals in the leather production process. During technological operations related to the skinning and processing of skins, these substances enter the wastewater, which is discharged into the sewer. A peculiarity of leather production wastewater is large fluctuations in composition and volume, high concentrations of pollutants, and an increased content of suspended solids. Such waters have certain toxicity. The existing methods of wastewater treatment of leather industry enterprises do not provide the necessary treatment efficiency, do not allow to create a closed circulation of water at enterprises, to use or regenerate valuable components of wastewater, and to ensure their economically feasible disposal. Therefore, the research is aimed at improving the process of coagulation wastewater treatment of leather factories using mathematical modeling and optimization methods. This will make it possible to modernize existing wastewater treatment schemes. The experiments were carried out on the Niva Jar-test laboratory unit, which allows simultaneous examination of 6 samples. Samples of wastewater from leather production after the fattening-filling and dyeing stages were studied. The effectiveness of the coagulation process was determined by the degree of wastewater treatment. The factors were analyzed and the intervals of variation of factors that have a significant impact on the process of coagulation treatment of wastewater from leather factories were established. An experiment plan was drawn up and implemented in order to study the effect of coagulants based on aluminum and ferrum, as well as flocculants on the quality of wastewater treatment. The choice of quality indicators of the coagulation process is substantiated. A statistical analysis of the results of experimental studies was performed, a correlational analysis of the interdependence of parameters and indicators of the quality of the coagulation process was performed. Aluminum-based coagulant has been found to be more effective than iron-based coagulant. The results of mathematical modeling were used to determine the optimal parameters of the coagulation process: pH 10, coagulant dose – 2.5 g/dm3, flocculant dose – 100 mg/dm3.

The use of Carica papaya seeds as bio coagulant for laundry wastewater treatment

The study aims to analyze the effectiveness of wastewater treatment by using Carica papaya seeds as bio coagulants to diminish total suspended solids (TSS) and excess phosphate. This method has some advantages because it does not use chemical materials, is simple to apply, and is safe for the environment and human health. The wastewater samples were taken from an active laundry site in Palembang City, South Sumatra Province of Indonesia. The study found that the best dosage of coagulant was 3 g for the wastewater samples. The pH and BOD parameters showed slight changes after treatment, with pH 7.63–7.19 and 33–27 mg/L values, respectively. The TSS removal efficiency ranged from 9.3 to 15.6%, while the COD and phosphate removals were obtained from 11.7 to 39.3% and 56.3 to 68.4%, respectively. The treated TSS, COD, and phosphate concentrations have met the Indonesian domestic wastewater quality standard and environmental protection organization (EPO) guidelines. In addition, the statistical analysis and t-test showed significant differences (p < 0.05) for before and after treatment data of all parameters. The ANOVA test showed significant differences (p < 0.05) for all parameters among the three treatments. Overall, the study indicated that C. papaya seeds are promising materials that are eco-friendly and useful to treat laundry wastewater.

Baobab Leaf Powder Efficacy as Turbid Water Treatment Biocoagulant

The high cost of treated water makes most rural communities resort to readily available sources that are normally of low quality, which exposes them to waterborne diseases in the process. In the present study, various doses of baobab (Adansonia digitata) leaf powder coagulant (i.e., 0.1, 0.2, and 0.3g per 50 mL turbid water) were added to the surface water sample collected. It was found that increasing the coagulant doses results in either a decrease or increase in the measured parameters, such as pH, turbidity, and electrical conductivity (EC). At constant 30 min coagulation time, pH and EC of the turbid water samples taken were within WHO standards. However, the labeled sample fed with 0.3g of baobab leaf powder coagulant gave the lowest turbidity of 78.7 NTU. A reduction in final turbidity is a clear indication of the coagulation capabilities of baobab leave powder. With this study, baobab leave (as a potential coagulant) is a new addition to the literature, apart from its seed and pulp which have been experimented with previously. Natural coagulants contain some chemicals whose effect on the resulting treated water needs to be examined. If need be, an additional treatment unit must be set up to adsorb or remove those contaminants from the water before proper use.

Influence of Type and Dose of Coagulants on Vehicle Wash Wastewater

The study was conducted to investigate the effect of the type and dosage of coagulant on changes in phosphate and fatty oil levels in liquid waste from motor vehicle wash. The independent variables in this study were the type of coagulant (Al2(SO4)3 and FeCl3) and the dosage of coagulant (0 ml, 3 ml, 5 ml, and 7 ml), while the dependent variables were the content of phosphate and fatty oil. The experiment was conducted in 3 stages; fast stirring, slow stirring, and precipitation. From the preliminary test, it was found that the phosphate content before processing was 12.9 mg/lt and the content of fatty oil was 1.9 mg/lt. The most significant decrease in phosphate content was found when 7 ml of FeCl3 was used as coagulant; it dropped to 0.11 mg/lt (efficiency: 99.2%). Meanwhile, the most effective coagulant for fatty oil was 3 ml of Al2(SO4)3; the fatty oil content dropped to 1.4 mg/lt (efficiency: 30.7%). The addition of Al2(SO4)3 gave the opposite effect on phosphate and fatty oil, making the process ineffective. Meanwhile, the data showed that FeCl3 could be used as an effective coagulant for phosphate and fatty oil. To determine the significance of the differences between the results of the Randomized Complete Block Design analysis, the researcher used Least Significant Design test. The results showed that the variation of the type of coagulant affected the decrease in phosphate and fatty oil levels, while the variation in dosage gave no significant difference.

Experimental and statistical models moisture release of the mixture treated with reagents raw sludge and compacted active sludge

The technology of changing the resistivity of a mixture of raw sludge and compacted activated sludge taken after the sludge pumping station of urban sewage treatment plants by treating the sludge with aluminum sulfate and polyacrylamide (PAA) in doses from 0 to 300 mg/dm3 has been tested. The degree of influence of each reagent on the process of dehydration of the sediment under study has been established. It has been shown that PAA has about 2.0 times greater effect on the process of moisture loss than Al2(SO4)3 at reagent doses from 0 to 200 mg/dm3 and about 1.5 times – at doses from 100 to 300 mg/dm3. Mathematical models of the dependence of the change in the resistivity of the sediment on the amount of Al2(SO4)3 and PAA introduced into it are obtained. Mathematical models are also presented in graphical form (isolines). The optimal doses of coagulant and flocculant for chemical treatment of the studied sewage sludge were determined.

Suitability of inorganic coagulants for algae-laden water treatment: Trade-off between algae removal and cell viability, aggregate properties and coagulant residue

Inorganic coagulants could effectively precipitate algae cells but might increase the potential risks of cell damage and coagulant residue. This study was conducted to critically investigate the suitability of polyaluminum (PAC), FeCl3 and TiCl4 for algae-laden water treatment in terms of the trade-off between algal substance removal, cell viability, and coagulant residue. The results showed that an appropriate increase in coagulant dosage contributed to better coagulation performance but severe cell damage and a higher risk of intracellular organic matter (IOM) release. TiCl4 was the most destructive, resulting in 60.85% of the algal cells presenting membrane damage after coagulation. Intense hydrolysis reaction of Ti salts was favorable for the formation of larger and more elongated, dendritic structured flocs than Al and Fe coagulants. TiCl4 exhibited the lowest residue level and remained in the effluents mainly in colloidal form. The study also identified charge neutralization, chemisorption, enmeshment, and complexation as the dominant mechanisms for algae water coagulation by metal coagulants. Overall, this study provides the trade-off analyses between maximizing algae substance removal and minimizing potential damage to cell integrity and is practically valuable to develop the most suitable and feasible technique for algae-laden water treatment.

A cloud-based infrastructure to deploy supervisory forecast models for predictive coagulant dosing control

Abstract Advanced optimal dosing control based on multiple online sensor data is operational in several treatment facilities in Norway. The benefits of the dosing control system in maintaining stable phosphate/solids removal and saving coagulant usage are documented in the literature. The dosing algorithm is currently implemented in a programmable logic controller (PLC) connected to the treatment plant's Supervisory Control and Data Acquisition System (SCADA) system. The PLC receives online sensor data from the plant's SCADA, calculates the optimal dosing values, and transmits optimal dosage values back to the SCADA system. The dosing algorithm is frequently updated to keep in sync with the process and equipment upgrades of the treatment plant and advances in control algorithm schemes. The upgrades include new regulatory feedback loops structural changes to the dose equation, and the addition of conditional setpoints. Each maintenance and upgrade routine entails operational downtime where the dosing algorithm is set to a sub-optimal flow-proportional dose. This paper presents a non-intrusive Internet of Things (IoT) infrastructure to implement a predictive/forecast component to an existing dosing control algorithm. The benefits of the new cloud-based system in improving nutrient removal, increasing operational flexibility, and reducing maintenance downtime are presented in this work.

Scattered and transmitted light as surrogates for activated carbon residual in advanced wastewater treatment processes: Investigating the influence of particle size

The use of powdered activated carbon (PAC) is a common process in advanced wastewater treatment to remove micropollutants. Retention and separation of PAC is essential as PAC loaded with micropollutants should not be released into the environment. Determining the activated carbon (AC) residual in the effluent poses a challenge, as there is currently no on-line measurement method. In this study, the correlation between turbidity, measured by scattered light, and absorption at wavelength of 550 nm (Absorption550 nm), measured by transmitted light, was investigated in relation to the AC residue. Linear correlations for turbidity (R2 = 0.95) and Absorption550 nm (R2 = 1.00) to AC concentrations were observed in both laboratory and full-scale experiments in a pilot plant where superfine PAC was added prior to Pile Cloth Media Filtration (PCMF). Decreasing the particle size (d50) while maintaining the same AC concentration leads to increased turbidity: Therefore, a fourfold reduction in d50 results in a 2- to 3-fold increase in turbidity, whereas a 30-fold reduction in d50 leads to a 6-to 8-fold increase. Furthermore, the original wastewater turbidity led to a parallel shift in the linear correlation between turbidity and AC. Coagulant doses of up to 400 mg Me3+/g AC resulted in a 50% reduction in turbidity. However, higher concentrations from 400 to 1,000 mg Me3+/g AC resulted in increased turbidity with only a 30% reduction compared to the initial turbidity. The study also highlights the significance of AC particle size in optical measurements, impacting result accuracy.

Applying Recurrent Neural Networks and Blocked Cross-Validation to Model Conventional Drinking Water Treatment Processes

The jar test is the current standard method for predicting the performance of a conventional drinking water treatment (DWT) process and optimizing the coagulant dose. This test is time-consuming and requires human intervention, meaning it is infeasible for making continuous process predictions. As a potential alternative, we developed a machine learning (ML) model from historical DWT plant data that can operate continuously using real-time sensor data without human intervention for predicting clarified water turbidity 15 min in advance. We evaluated three types of models: multilayer perceptron (MLP), the long short-term memory (LSTM) recurrent neural network (RNN), and the gated recurrent unit (GRU) RNN. We also employed two training methodologies: the commonly used holdout method and the theoretically correct blocked cross-validation (BCV) method. We found that the RNN with GRU was the best model type overall and achieved a mean absolute error on an independent production set of as low as 0.044 NTU. We further found that models trained using BCV typically achieve errors equal to or lower than their counterparts trained using holdout. These results suggest that RNNs trained using BCV are superior for the development of ML models for DWT processes compared to those reported in earlier literature.

Optimization of Coagulation to Remove Turbidity from Surface Water Using Novel Nature-Based Plant Coagulant and Response Surface Methodology

Plant-based natural coagulants are considered potential alternatives to chemical coagulants. These are eco-friendly, non-toxic, and produce less sludge compared to chemical coagulants. This study aims to evaluate the coagulation potential of a novel plant-based coagulant Sorghum for canal water treatment. In addition, a coagulant aid, i.e., Aloe Vera, was also tested to examine any further increase in turbidity removal through a jar test apparatus. Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) were used to characterize the coagulants. The experiment was designed using response surface methodology (RSM). When used alone, Sorghum resulted in a maximum turbidity removal of 87.73% at pH 2 and a dose of 40 mg/L, while the combination of Sorghum and Aloe Vera resulted in a turbidity removal of 84.2% at pH 2.7, and the doses of Sorghum and Aloe Vera were 17.1 mg/L and 0.9% (v/v), respectively. Thus, the Sorghum dose was significantly reduced when Aloe Vera was used in combination. At a pH of 7, Sorghum achieved 54% turbidity removal at a dose of 55.7 mg/L. Analyses of variance revealed that pH plays a more vital role in the removal of turbidity than the coagulant dose. FTIR and SEM analyses revealed that adsorption is the dominant coagulation mechanism for plant-based coagulants. The Sorghum powder exhibited carboxylic, amine, and carbonyl groups that functioned as active adsorption sites for suspended solids. In a similar vein, the coagulant aid Aloe Vera gel facilitated the adsorption process by fostering intermolecular hydrogen bonding between suspended particles and amine groups present within the gel.

Heavy metals removal from industrial wastewater using date seeds powder and aluminum chloride-based hybrid natural/chemical coagulation

High levels of heavy metals in industrial wastewater pose a significant environmental concern due to their toxicity to living organisms and ecosystems. Traditional techniques that use chemical coagulants to eliminate heavy metals from industrial wastewater have proven effective. However, the use of chemical coagulants produces sludge that is highly toxic and requires careful management. On the other hand, natural coagulants offer a cost-effective and sustainable alternative that is safer to handle, locally available, and potentially useful for resource recovery. These benefits make natural coagulants a promising substitute for chemical coagulants. This study aimed to investigate the performance of combining Date stone powder (DSP) and aluminum chloride (AlCl3), to remove heavy metals from industrial wastewater efficiently. Through an optimization process of DSP/AlCl3 dosage and pH, the study sought to determine the optimal conditions for heavy metal removal. The main findings indicate that a DSP/AlCl3 dosage of 7:1 (g/g) was the most effective coagulant dosage, resulting in high removal efficiencies for COD (88.56%), color (89.56%), TSS (99.00%), NH3-N (92.50%), Mn (94.10%), Fe (95.47%), Zn (93.57%), Al (88.42%), and Ni (93.3%) at pH 8. Interestingly, the results of pH optimization showed that no pH modification was necessary, as it already achieved high removal efficiencies for COD (84.57%), color (88.94%), TSS (99.00%), NH3-N (92.25%), Mn (92.66%), Fe (90.57%), Zn (95.59%), Al (99.00%), and Ni (93.33%). This study demonstrates that the hybrid DSP/AlCl3 coagulation method can be an effective and sustainable solution for removing heavy metals from industrial wastewater. However, further research is necessary to assess its scalability and potential limitations.

The practical meaning of the classical optimizing method and Angular Detection Photometer (ADP) in coagulation tests of surface water

Because of the growing deficit of clean water, rational use of its supplies through adaptation of purification techniques to the needs is becoming vital. The commonly used coagulation process requires optimization tools and techniques. The following were used in this paper to optimize coagulation of natural water pollutants: the standard jar test method with direct filtration and the angular detection photometry (ADP) method. We tested two aluminium coagulants – PAC with different basicity – and an iron coagulant: PFS. A modified jar test method allowed to obtain results similar to those of the sedimentation method. At the optimum doses 1.3 mg Al/mg C org. and 2 mg Fe/mg Corg – colour (PtCo), A254, A436 – achieved reduction in the 84–96% range and DOC 60–67% after filtration. The titration method using an ADP successfully allows determine optimum coagulant doses. The SD and FI values were determined based on the recorded fluctuations of the signals measured by detectors placed at three angles relative to the IR beam. A variation in SD was observed, depending on the angle of detection and the coagulant and correlates well (R2 =0.6–0.86) with sedimentation time ST, which was twice as long in the case of fine suspension in the PFS.

Coagulation process for the removal of color and turbidity from wet coffee processing industry wastewater using bio-coagulant: Optimization through central composite design

The growing problem of industrial pollution in developing countries, especially Ethiopia, has sparked serious issues about the quality of the water, particularly when it comes to the effluent from wet coffee processing industries. In response, this study investigates the potential of utilizing natural coagulants, Acanthus sennii C., Moringa stenopetala B., and Aloe vera L., either individually or in combination, for the treatment of coffee effluent. Methodologically, the study systematically varies operational parameters, including coagulant dose, pH levels, stirring speed, and stirring time, to evaluate their impact on coagulation efficiency. Experimental data undergo statistical analysis, employing ANOVA, while computational optimization techniques are employed using Design Expert software to determine optimal conditions. Notably, the blended form of the three coagulants emerges as particularly promising, yielding optimal conditions of 0.750 g/L coagulant dosage, pH 8.76, agitation speed of 80.73 rpm, and agitation time of 19.23 min. Under these optimized conditions, the blended coagulant achieves remarkable removal efficiencies, approximately 99.99% for color and 98.7% for turbidity. These findings underscore the efficiency of natural coagulants, particularly in blended form, for sustainable wastewater treatment in wet coffee processing.

Small water supply system with plasma-modified poly(tetrafluoroethylene) membrane for drinking water production

The small water supply systems aim at supplying safe drinking water to small communities in remote areas. This study applies an automatic small water supply system comprising 20 plasma-grafted poly(tetrafluoroethylene) (PTFE) membranes with a 1.42 m2 filtration area to generate permeate at a capacity of 3 m3/day from raw water collected from a local river. The system was tested by 34 days in phase I with bubble scraping and by 120 days in phase II without bubbling, with water quality, cross-membrane pressure drops, and dissolved organic carbons’ and foulants’ characteristics being recorded. Even with typhoon water turbidity up to 1714 nephelometric turbidity units (NTU), the system yields drinking water, meeting Taiwan’s standards. The system is fully automatic with no coagulant or disinfectant doses; an operational cost of 0.21 USD/m3 is proposed, much lower than the tariffs applied in most countries. The foulant characteristics and washing efficiencies noted are discussed.

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.

Mechanism for the synergistic removal of Sb(Ⅲ) and Sb(V) from printing and dyeing wastewater by polyferric sulfate

Herein, the synergistic removal of Sb(Ⅲ) and Sb(Ⅴ) from wastewater by polymeric ferric sulfate (PFS) and the oxidation process were investigated. The results showed that PFS exhibited superior performance on Sb(Ⅲ) removal in terms of coagulant dosage, applied pH, and anti-interference properties than Sb(V) removal. For the Sb liquid in pure water matrix (Sb=1000 μg/L), when the dose was 60 mg/L and the final pH was 5.0, the independent removal of Sb(Ⅲ) and Sb(V) was 95% and 90%, respectively. Meanwhile, Sb(Ⅲ) removal in the PFS coagulation system remained stable within a wider pH range (pH=3–9). Sb(Ⅲ) could be preferentially removed in the solution column and had an inhibitory effect on the adsorption of Sb(V). Sb(Ⅲ) was also partially oxidized to Sb (V) during the coagulation process, which was influenced by the coagulant dosage and the solution pH. The results of the actual printing and dyeing wastewater (PDW) treatment indicated that the pre-reduction of Sb(V) to Sb(Ⅲ) could significantly increase the total Sb removal from 72.0% to 97.5%. The characterization results, such as Zeta potential and x-ray photoelectron spectroscopy (XPS), indicated that the Sb(Ⅲ) removal by PFS was achieved mainly through chemical adsorption. While the Sb(V) removal was realized by both chemical adsorption and electrostatic adsorption, the electrostatic adsorption contributed more than the chemical adsorption. This study provides a new idea for understanding the synergistic removal of Sb(Ⅲ) and Sb(V) using PFS in PDW advanced treatment.

Use of Plant-Based Coagulants Sorghum Bicolor and Trifolium Repens as Future Alternatives for Textile Wastewater Treatment Based on Computational Model

Sorghum bicolor and Trifolium repens extracts as plant coagulants can be used for wastewater treatment instead of chemical coagulants. This study investigates the effects of pH and coagulant dose on COD and turbidity reduction by natural coagulants. In the optimum treatment conditions of 100 mg/L coagulant dose and pH 7, high turbidity (81.34%), and COD reduction (62%) (compared with alum and FeCl3) were obtained. The percentage of COD reduction is higher in Trifolium repens than the other plant coagulant, and the percentage of turbidity reduction is higher in Sorghum bicolor. FT-IR spectra were performed on the plant extracts to identify the existing factors in active extracts. Also, outlet COD and turbidity values can be predicted and calculated according to computational equation in similar treatment systems. It should be mentioned that the only applied solvent for extracting the natural coagulant seeds was distilled water, and none of the other solvents such as NaCl and NaOH were used. According to the results, the characteristics of the treated effluents by the plant extracts make them appropriate alternatives for textile wastewater treatment.

Biochemical and toxicological profiles of venoms from an adult female South American bushmaster (Lachesis muta rhombeata) and her offspring

In this work, we compared the biochemical and toxicological profiles of venoms from an adult female specimen of Lachesis muta rhombeata (South American bushmaster) and her seven offspring born in captivity, based on SDS-PAGE, RP-HPLC, enzymatic, coagulant, and hemorrhagic assays. Although adult and juvenile venoms showed comparable SDS-PAGE profiles, juveniles lacked some chromatographic peaks compared with adult venom. Adult venom had higher proteolytic (caseinolytic) activity than juvenile venoms (p < 0.05), but there were no significant inter-venom variations in the esterase, PLA2, phosphodiesterase and L-amino acid oxidase (LAAO) activities, although the latter activity was highly variable among the venoms. Juveniles displayed higher coagulant activity on human plasma, with a minimum coagulant dose ∼42% lower than the adult venom (p < 0.05), but there were no age-related differences in thrombin-like activity. Adult venom was more fibrinogenolytic (based on the rate of fibrinogen chain degradation) and hemorrhagic than juvenile venoms (p < 0.05). The effective dose of Bothrops/Lachesis antivenom (produced by the Instituto Butantan) needed to neutralize the coagulant activity was ∼57% greater for juvenile venoms (p < 0.05), whereas antivenom did not attenuate the thrombin-like activity of juvenile and adult venoms. Antivenom significantly reduced the hemorrhagic activity of adult venom (400 μg/kg, i. d.), but not that of juvenile venoms. Overall, these data indicate a compositional and functional ontogenetic shift in L. m. rhombeata venom.