Coagulation pH Research Articles

Improving the Removal of Anionic Surfactant in Cardboard Industry Wastewater by Coagulation/Flocculation: Process Optimization with Response Surface Methodology

Response surface methodology (RSM) and Box–Behnken design (BBD) were investigated to optimize the coagulation–flocculation process (CF) of cardboard industry effluent using polyaluminum chloride (PAC) and cationic polyacrylamides (c-PAM). The aim is to identify the optimum combination of coagulant dose, pH, and flocculant dosage for the highest removal efficacy of chemical oxygen demand (COD) and anionic surfactant removal. According to the results, COD reduction was principally controlled by PAC and c-PAM, while anionic surfactant was affected by pH and PAC. In addition, COD and anionic surfactant removal models fitted well with the experimental results (R2 > 0.85). Coagulation/flocculation using optimum conditions of pH, PAC, and c-PAM led to the total removal of anionic surfactant and the reduction of more than 95% of COD.

Deep removal of fluoride from tungsten smelting wastewater by combined chemical coagulation-electrocoagulation treatment: From laboratory test to pilot test

Previous studies have shown that coexisting ions in tungsten smelting wastewater (TSW) will have a significant impact on fluoride removal by calcium ions. Therefore, in this work, the removal of fluoride from TSW by aluminum ions was studied. Electrocoagulation (EC) is essentially the use of aluminum ions to remove fluoride. The EC technology is widely favored by researchers due to its advantages of high treatment efficiency, simple operation, and easy automatic control. However, in the current research, EC technology as a deep defluorination method is mostly in the laboratory research stage, and there are few pilot test studies on large processing capacity, which slows down the industrial application of this technology to a certain extent. In this work, laboratory tests were carried out to study the removal of fluoride in wastewater by chemical coagulation and EC in detail. On this basis, the combined process of chemical coagulation pretreatment and EC advanced treatment was used to treat TSW with a capacity of 250–500 L/h. The results show that the coexisting ions in TSW have no effect on the defluorination of aluminum ions, and the optimal defluorination final pH of chemical coagulation and EC is 6–7. The pilot test could stably reduce the concentration of fluoride in TSW from 66 to 128 mg/L to less than 10 mg/L, and the total operating cost was 0.99–1.51 USD/m3 of wastewater. Cost analysis showed that the three items with the highest proportions in the chemical coagulation pretreatment costs were liquid caustic soda fee, aluminum sulfate fee, and solid waste treatment fee; while the three items with the highest proportions in the EC advanced treatment costs were aluminum plate loss fee, electricity fee, and solid waste treatment fee. This study is helpful to promote the application of EC advanced treatment technology in the defluorination of industrial wastewater.

Pengaruh Penambahan Ekstrak Jeruk Purut (Cytrus hitrix D.C) Sebagai Koagulan Alami Terhadap Karakteristik Karet

Natural rubber is a plantation commodity that has a significant role in the country's economy. This study aims to determine the effect of the natural coagulant extract of kaffir lime with centrifugation and non-centrifugation treatment on the coagulation process, pH and coagulation time, characteristics of rubber clone IRR 118 and comparison of the quality of rubber with 2% formic acid chemical coagulant. The volume of coagulant used was 75 mL mixed with 150 mL of latex, so that coagulation occurred and produced coagulum. Then the resulting coagulum is analyzed for the characteristics of the rubber to determine the quality of the rubber. Characteristic analysis carried out was Dry Rubber Content (DRC), Initial Plasticity (Po), Plasticity Retention Index (PRI), Mooney Viscosity, ash content, impurities content, volatile matter content, and nitrogen content. The results showed that the natural coagulant extract of kaffir lime could coagulate latex, lowering the pH of latex thereby speeding up coagulation time. From the rubber characteristic test using kaffir lime natural coagulant it complies with SNI 06-1903-2017 SIR 20. The quality of rubber produced from using kaffir lime natural coagulant extract as a coagulant can equate the quality of rubber produced by using 2% formic acid chemical coagulant, but coagulant The natural ingredients used have drawbacks, namely the availability of seasonal fruit, and the need for treatment before being used as a coagulant.

The Utilization of Pectin as Natural Coagulant-Aid in Congo Red Dye Removal

Coagulation using inorganic compounds such as aluminum sulfate is commonly used in water-wastewater treatment. However, there are some drawbacks to its utilization, such as a significant decrease in the treated water’s pH, non-biodegradable sludge, and a potential negative impact on human mental health (dementia and Alzheimer's). The use of inorganic coagulants can be minimized with the addition of natural-based coagulant-aid such as pectin. In this study, Congo red solution, a model dye substance, was coagulated by varying the pH (3–7) using alum coagulant to determine the best pH for coagulation. At the best pH, pectin was introduced at various doses (0–30 mg/L), and subsequently various dye concentrations (50–100 mg/L). The effect of pectin as coagulant-aid was compared with aluminum sulfate and pectin only; with a response of %removal and sludge volume. It was found that the Congo red dye coagulation had the best %removal at pH 6 indicating a charge neutralization mechanism. The addition of 15 mg/L pectin at an aluminum sulfate dose of 30 mg/L resulted in 97.7% dye removal with a sludge volume of 14 mL/L at a Congo red concentration of 50 mg/L. This value is higher compared to those of aluminum sulfate and pectin only which gave 75.6 and 3.19% removals, respectively. Furthermore, the addition of pectin as a natural coagulant-aid could halve the sludge volume due to the formation of denser flocs. The results show a promising potential of pectin as a natural coagulant-aid in water-wastewater treatment.

Water purification improvement using moringa oleifera seed extract pastes for coagulation follow scoria filtration

Currently, millions of people are exposed to dangerous levels of chemical and biological water pollution in drinking water due to source contamination. The rising of populations and industrialization or agricultural wastewaters were causes of water contaminations. The aim of this study was to design, develop and performance evaluation of point of use drinking water purification technology using MoringaOleifera seed coupled followed by scoria coag-filtration media. Experimental laboratory based aquas solution of contaminated water was prepared for evaluations. Moringa Oleifera seed coagulation/flocculation and sedimentation tests were carried out using jar test with the batch experiment. The potential treatment of the sequential ordered unit process stages were evaluated by the determination of physicochemical parameters of the water; such as turbidity, Color, PO4−3, Fe+3 and F−concentration. The factor that affects the purification where coagulant doses, pH, and contact time. Based on this, the physicochemical parameter analysis indicated that turbidity from (150-8NTU), PO4−3 (20–5.95 mg/L), Fe+3 (7–2.93 mg/L) and F− (9–2.83 mg/L), Moringa Oleifera seed dose (10–40 mL/L) extract paste. The maximum pollutant removal efficiency was achieved at 35 mL/L of Moringa Oleifera seed extractdose, within 6.5–7.5 pH range. Then VSco filtration was conducted after jar test under small column experiment as a function of contact time (0, 2, 4 h s). The VSco removal capacity showed that the removal of turbidityfrom (8–2.54NTU), PO4−3 (5.95–1.07 mg/L), Fe+3 (2.93–0.43 mg/L) and F− (2.83–1.94 mg/L) were achieved after 4hr detention time. The percent removal of turbidity, PO4−3, Fe+3 and F− increases remarkably with increasing of their initial concentration. At an initial concentration of turbidity (150NTU), PO4−3 (20 mg/L), Fe+3 (7 mg/L) and F−(9 mg/L), the removal efficiency were 98%, 84%, 85% and 60% respectively. Therefore, we recommend Moringa Oleifera seed –Vscoas an economic, efficient and simple Point of Use drinking water treatment technology.

Statistical computation and artificial neural algorithm modeling for the treatment of dye wastewater using mucuna sloanei as coagulant and study of the generated sludge

Adaptive neuro-fuzzy inference system and response surface methodology techniques were used to predict coagulation-flocculation parameters needed to remove color and COD effectively and produce acceptable sludge using Mucuna sloanei at 298 K from a dye wastewater. The variables input to the network were coagulant dosage (1000, 1400 and 1800 mg/L), solution pH (2, 6 and 10) and stirring time (5, 15 and 25 min). Coefficient of determination, R2 and root mean square, RMSE were used to evaluate the adequacy and predictive relevance of the two techniques. Color removal model indicators are R2 0.9823, RMSE 0.2599 and R2 0.8616, RMSE 21.403 for ANFIS and RSM, respectively; COD removal indicators are respectively, R2 0.9752, RMSE 0.2009, and R2 0.9741, RMSE 0.8118 for ANFIS and RSM; while sludge volume index model indicators are R2 0.9950, RMSE 0.2341, and R2 0.9930, RSME 2.1436, for ANFIS and RSM, respectively. With a limited set of data, the generated models produced idealized findings and were proven to be useful for forecasting color and COD elimination, and SVI. Nevertheless, the ANFIS model is clearly favored because of greater R2 values and lower RMSE.

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 calculated according to computational equation in similar treatment systems where using the same plant coagulants. 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.

Self-Tuning Pid (STPID) Control of pH in Recovering Process of Magnesium Hydroxide (Mg(OH)2) by Coagulation From Salt

The salt obtained from the salt sources are not desirable purity level and contains some impurities. In the scope of this study, coagulation of magnesium hydroxide (Mg(OH)2) in pH control has been carried out by adding sodium hydroxide (NaOH) to magnesium chloride (MgCl2) and by this way recovery process has been achieved by Self Tuning PID Control. To provide the best coagulation pH 11 has been obtained as optimum pH value in consideration of the performed calculations.

Application of xanthan gum as coagulant-aid for decolorization of synthetic Congo red wastewater

In recent years, utilization of polysaccharides as natural coagulant and coagulant-aid has become a topic of interest, due to the nature of biopolymers that are renewable, biodegradable, and non-toxic. In this study, Congo red, as a model dye substance, was treated using polyaluminium chloride (PAC) as the main coagulant and xanthan gum as the coagulant aid. For this purpose, the effect of pH (3–9), xanthan gum dose (0.5–4 mg/L), and the initial concentration of Congo red dye (50–100 mg/L) to the dye removal and sludge volume were investigated. The outcome of this investigation indicates that the best pH for Congo red coagulation occurred at pH 3, due to the charge neutralization mechanism. The addition of coagulant-aid dose increases the %-removal and sludge volume until reaching the best coagulant-aid dose of 2 mg/L that results in a %-removal value of 93.81% and a sludge volume of 23.5 mL/L. Further addition of xanthan gum reduced the %-removal and sludge volume due to the inter-polymer force causing more difficult floc formation. The best initial concentration of dye occurred at a Congo red concentration of 50 mg/L, with a %-removal value of 93.81% with PAC (15 mg/L) and xanthan gum (2 mg/L) coagulants. This value is considerably higher than PAC and xanthan gum only which amounts to 81.16 and 7.18%, respectively. Based on these results, it is apparent that xanthan gum can positively contribute to dye coagulation while reducing the use of harmful inorganic coagulant.

Suspended matter and heavy metals (Cu and Zn) removal from water by coagulation/flocculation process using a new Bio-flocculant: Lepidium sativum

BackgroundThe pollution of surface waters, due to the demographic and economic growth, requires very complex ways of treatment, where the world concern is focused on the substitution of synthetic products commonly used for the depollution of waters, by other natural elements, to ensure sustainable development. Moreover the main object of our study is to exploit natural supports, as bio polymers able to substitute the synthetic polymers used as aids of flocculation in the treatment of waters loaded with suspended solids (SS), and heavy metals, notably copper and zinc. For this purpose we used a new organic bio-flocculant, which we extracted from natural Lepidium sativum (LS) seeds, used for the first time as a flocculation aid to reduce the coagulant salt, improve the conglomerates of generated flocs, and ensure the removal of Copper and Zinc. Namely that the LS extract is known for its performance in various fields such as cosmetology, pharmacology and food products. Moreover, it does not present any danger for human health. MethodsOur preliminary flocculation tests were carried out on samples prepared at the laboratory level, and various operating parameters were studied such as: pH, nature and concentration of coagulant and bioflocculent content. After treatment, turbidity is monitored by nephelometric method, trace elements are analyzed by AAF and other spectroscopic methods are used (UV–Visible, SEM/EDS, XRD). Significant findsMucilage efficiency is studied in comparison with other products usually used in water treatment and depollution. The comparative study with a synthetic flocculant, anionic (Polyacrylamide: PAM), offers a good competitiveness with an important flocculation power. The association of the two stages of coagulation by the neutralizing salt, followed by flocculation using a new bioflocculent extracted from LS, gave significant results, in the abatement of SS in particular that based on marly limestone, where the turbidity passes from an average of 600 NTU to values close to 1NTU, as well as with the major elements in heavy metals (Copper and Zinc) of which a notable rate of elimination. The sludge generated after treatment using bioflocculent was found compact with less volume and it's same to the one generated from PAM synthesis flocculent. The first one was subjected to (SEM/EDS) and XRD analyses, all the chemical elements retained are detected after confirming that this sludge has less danger on the environment.

Comparison of milk and grass composition from grazing Irish dairy herds with and without milk fat depression

BackgroundThis study investigated the factors relating to pasture chemical and fatty acid (FA) composition that influence the milk fat percentage of spring calving, grazing dairy cows. The relationship between milk fat percentage and FA composition of the milk in these herds was also investigated.ResultsMilk protein percentage, milk casein percentage and cheddar cheese yield were increased in milk from HMF herds. Cows from LMF herds did not have negatively altered milk processability including rennet coagulation time (RCT), pH and ethanol stability. Crude protein, NDF, ADF, ether extract and total FA content of pasture was not different between LMF and HMF herds. Milk fat concentration of conjugated linoleic acid (CLA) t10, c12 was not different between HMF and LMF herds. Pre-grazing herbage mass and pasture content of crude protein, neutral detergent fibre (NDF) and total FA were similar between HMF and LMF herds. Pasture offered to LMF herds had a higher concentration of monounsaturated fatty acids (MUFA). A strong negative relationship (r = -0.40) was evident between milk fat percentage and pasture crude protein content for MMF herds (3.31–3.94% milk fat).ConclusionsThis research reports improved milk protein percentage, milk casein percentage and cheddar cheese yield from HMF herds compared to LMF herds. Milk processability was not impacted by low milk fat percentage. Pasture NDF and total fatty acid content was similar in HMF herds and LMF herds. Milk fat percentage had a strong negative association (r = -0.40) with pasture crude protein content in MMF herds (MF 3.31–3.94%). Correlation values between pasture chemical and FA composition and milk fat percentage in LMF herds and HMF herds were low, indicating that diet is not the only causative factor for variation in milk fat of grazing dairy cows. Comparison of milk fatty acid composition from herds with and without milk fat depression suggests that there may be other fatty acids apart from CLA t10, c12 that contribute to the inhibition of milk fat synthesis during milk fat depression in grazing herds.

Characterization of Textile Dyeing Effluent and Removal Efficiency Assessment of Al2(SO4)3 Coagulant

The textile dyeing industry discharges a variety of effluents into nearby surface water bodies, which pose a threat to the environment. The study aimed to characterize the effluents and evaluate the coagulant efficiency of Al2(SO4)3 for the treatment of textile effluent. This investigation deals with studying the parameters affecting coagulation-flocculation (C-F) behavior, such as coagulant dose, reaction time, pH, and temperature, using a jar test apparatus. The analyzed parameters before and after treatment are pH, dissolved oxygen (DO), electrical conductivity (EC), total suspended solids (TSS), total dissolved solids (TDS), chemical oxygen demand (COD), biological oxygen demand (BOD), and some anions. The analysis results showed that the textile dyeing effluent was highly alkaline, and parameters like EC, TSS, TDS, COD, BOD, and some anions were found to be higher than the DoE-BD standard guidelines for effluent discharge, indicating that the effluents are loaded with high amounts of organic and inorganic pollutants. The study optimized the process parameters of the coagulation The study optimized the process parameters of the coagulation, which illustrated that the Al2(SO4)3 coagulant potentially reduced pH, EC, TDS, TSS, BOD, and COD from the effluents. The study observed that the highest removal of COD and BOD was 66% and 74% for the samples Ef2 and Ef3, respectively. The highest TSS removal rate was around 90% for Ef3, and almost 80% TDS removal was achieved for all effluents. The results indicated that Al2(SO4)3 showed a better coagulant efficiency for reducing the concentration of several physicochemical parameters in wastewater, and the treated effluent satisfied the DoE-BD standards for discharging wastewater into the public sewage network. Hence, Al2(SO4)3 would be a potential coagulant for treating the textile effluents that help to build a sustainable environment.

The Effect of Acetic Acid and Hydrochloric Acid as a Solvent for Chitosan to Reduce Turbidity in Eutrophic Water

In this research, the potential of chitosan as a coagulant to reduce the turbidity of eutrophic water was investigated. To examine the possible effect of the solvent of chitosan on its performance in reducing the turbidity of eutrophic water, different types of acid, i.e. acetic acid and hydrochloric acid, were used to dissolve chitosan, in which the concentration of each acid was also varied. The chitosan dissolved in acetic acid was labeled as Chit-AA while the one being dissolved in HCl was labeled as Chit-HCl. A standard jar test apparatus was used to determine the optimum dosage and coagulation pH for both Chit-AA dan Chit-HCl. Both Chit-AA and Chit-HCl gave optimum results at a dosage of 10 mg/L, where the turbidity reductions after coagulation with Chit-AA and Chit-HCl were 64.78% and 85.33%, respectively. The optimum coagulation pH for Chit-AA was pH 7 while Chit-HCl gave an optimum result at pH 8. The concentration of the acid being used to dissolve chitosan appeared to affect the decrease in turbidity, where a higher acid concentration lead to a higher decrease in turbidity.

Evaluation of Turbidity and Color Removal in Water Treatment: A Comparative Study between Opuntia ficus-indica Fruit Peel Mucilage and FeCl3.

Natural coagulants derived from by-products have gained popularity as sustainable alternatives to inorganic coagulants in water/wastewater treatment due to their abundant availability, biodegradability, low cost, easy disposal and low sludge volumes. In this study, the mucilage obtained from the peel of Opuntia ficus-indica fruit was evaluated as a biocoagulant for treating synthetic turbid water and compared with a traditional chemical coagulant (FeCl3). The effects of coagulant dosage and pH on the turbidity and color-removal efficiency of synthetic turbid water were analyzed. To estimate the coagulation mechanism, the flocs produced under optimal values were characterized structurally (FTIR and zeta potential) and morphologically (SEM). The optimal condition for the removal of turbidity and color was a coagulant dose of 12 mg/L at pH 13. For the optimal values, the biocoagulant and the FeCl3 presented a maximum removal of 82.7 ± 3.28% and 94.63 ± 0.98% for turbidity and 71.82 ± 2.72% and 79.94 ± 1.77% for color, respectively. The structure and morphology of the flocs revealed that the coagulation mechanism of the mucilage was adsorption and bridging, whereas that of FeCl3 was charge neutralization. The results obtained showed that the mucilage could be used as an alternative coagulant to replace FeCl3.

Turbidity Removal from Kaolin Synthetic Wastewater via Coagulation Process Using Sludge from Water Treatment Plant

This studyaims to treat kaolin synthetic wastewaterby using sludge from water treatment plant as a coagulant via the coagulation process. Water treatment sludge (WTS) was characterized by using Fourier transform infrared (FTIR), Scanning electron microscope (SEM), and X-ray diffraction (XRD). WTS had an amorphous structure and contained high aluminium metal constituents at 25.3%, which can be recovered as a coagulant. Acidification was conducted to recover the aluminium in WTS using sulphuric acid and produced water treatment sludge coagulant (WTSC). The optimum condition of WTSC prepared from WTS was evaluated through sludge concentration and acid dosage parameters. It has been observed that 0.5% sludge concentration acidified with 0.08 ml/ml sulphuric acid and normality constant at 0.5N was the optimum condition as it can remove turbidity at 99.5%. The performance of WTSC in the coagulation process using a standard jar test was studied based on the effect of pH and dosage of coagulant. The highest percentage turbidity removal (98.66%) was obtained at pH 12, kaolin turbidity was 117NTU, and WTSC dosage at 40mg/L. The percentage turbidity removal for alum and WTSC was almost similar. Thus, WTSC can potentially replace alum as a coagulant in water treatment plant (WTP).

Effect of Suspended Solids and Organic Matter in Water on the Removal of ZnO-NPs by Coagulation

Background: Zinc oxide nanoparticles (ZnO-NPs) have been shown to have a non-negligible impact on the environment Objective: Kaolin and humic acid were used in the aqueous environment to study their effects on the removal of ZnO-NPs. Method: In this work, polyaluminum ferric chloride (PAFC)/cationic polyacrylamide (CPAM) coagulants were used together with kaolin and humic acid were used to study their effects on the removal of ZnO-NPs and to analyze their mechanism of action. Results: The results showed that the removal rate of ZnO-NPs in the humic acid system decreased by about 30% compared to that in the pure water system, and increasing the ionic strength and humic acid concentration was not conducive to removing ZnO-NPs. On the other hand, the ZnO-NPs removal rate in the kaolin system was up to 96.28%, and increasing the ionic strength and kaolin concentration contributed to the removal of ZnO-NPs. In the humic acid and kaolin systems, the effects of coagulant dosage and pH on the removal of ZnO-NPs were about the same as in the pure water system. Moreover, 5 mg/L humic acid inhibited floc growth during removal of ZnO-NPs by coagulation with PAFC/CPAM. In contrast, 5 mg/L kaolin promoted flocs growth, resulting in stronger and more stable flocs and a 5.25% increase in the fractal dimension compared to the pure water system. Conclusion: These results suggested that suspended solids and natural organic matter in the water could directly affect the effectiveness of coagulation to remove ZnO-NPs.

Vortex coagulation treatment of oilfield wastewater.

In this study, the traditional coagulation process was optimized and a method of vortex coagulation for wastewater treatment was proposed for the first time. The process discards the sedimentation method used in traditional coagulation and uses agitation to bring flocs up. These flocs can then be stuck by the filter cotton fixed in wastewater, and the filter cotton and flocs can act as net capturing several times under the action of agitation. It is worth noting that the filter cotton and flocs can synergistically adsorb the suspended and organic pollutants from wastewater. The results showed that the chemical oxygen demand (COD) removal of vortex coagulation could reach 82%, which was 10% higher than that of the traditional coagulation under the same coagulant dosing. In addition, the flocs in conventional coagulation and vortex coagulation were analyzed by IR spectroscopy and XRD, which showed that the mixing process did not destroy the chemical structure of the flocs. Compared with the conventional method, this process does not require a sedimentation tank, which can avoid the investment of equipment construction in this area. The effects of coagulant dosage, pH, stirring speed, and stirring time on the wastewater treatment effects were explored in the experiment.

Influence of fulvic acid sub-fractions on aggregation kinetics of graphene oxide in aqueous environments

Fulvic acid (FA) can affect the dispersion of graphene oxide (GO) in aquatic environments, however, the possible mechanisms remain unclear. Dynamic light scattering techniques combined with a multiple regression model were applied to explore the influence of FA sub-fractions (FApH3 − FApH13) on the aggregation kinetics of GO in aqueous environments. The ratios of critical coagulation concentration (CCC) values were CCCNa: CCCMg: CCCLa: CCCCe = 1:2–5.15:3–7.31:3–7.35, which were consistent with the Derjaguin−Landau−Verwey−Overbeek (DLVO) theory and Schulze−Hardy rules. The GO remained stable at pH 3–10 and aggregated at pH < 3 or pH > 10, and its critical coagulation pH values were 1.44 and 12.25 with 10 mM NaCl as background. The CCC values of GO in the presence of FApH3 − FApH13 were greater than those in the absence of FA sub-fractions. The ratios of CCC values of GO (r) increased in the presence of FA sub-fractions in the order of FApH13 > FApH9 > FApH7 > FApH5 > FApH3 and ranged from 1.01 to 2.15 for certain metal ions including Na+, Mg2+, La3+, and Ce3+. The CCC values of GO were significantly related to C, H, O, N, S, H/C, O/C, carboxylic C, and carbonyl C of FA sub-fractions (P < 0.05), respectively, and could be predicted using the multiple linear regression eq. CCC = Z-n (98.959– 60.911 ∗ O/C + 4.799 ∗ O-alkyl C – 0.845 ∗ aromatic C – 6.237 ∗ carbonyl C). The predicted CCC values for GO were within 90 % prediction intervals, and the average error of the CCC values was 3.3 % and R2 = 0.986. This investigation is expected to provide a scientific basis for the transport and ecotoxicity of GO in environments.

Quinolones in goats' milk: Effect on the cheese-making process, chemical and microbial characteristics of acid-coagulated cheeses

The effect of the presence in goats' milk of enrofloxacin and ciprofloxacin on cheese-making and the characteristics of acid-coagulated cheeses was evaluated. Raw goats' milk was spiked with quinolones at maximum residue limit concentration (100 μg kg−1). For each antibiotic, three batches of cheese were made by acid coagulation (pH 4.6) using a commercial starter culture. Cheese-making process, gross composition and microbial counts in the cheeses were unaffected by the presence of quinolones in milk. However, relatively high amounts of these substances were retained in the cheeses, with residual concentrations of 146.5 ± 4.9 μg kg−1 and 150.7 ± 25.7 μg kg−1 for enrofloxacin and ciprofloxacin, respectively, after 20 days of maturation. Results suggest that the use of goats' milk containing legally admissible amounts of enrofloxacin and/or ciprofloxacin would have no impact on cheese manufacturing, composition and microflora of acid-coagulated cheese. However, the transfer of these substances to the final products could compromise consumer safety.

Kombinasi Green Coagulant dan Adsorben GAC (Granular Activated Carbon) Sebagai Pengolahan Limbah Cair Batik

The batik industry, especially in the Jetis Sidoarjo batik home industry, in its production has several processes that produce waste in the form of waste, both in the form of solid, liquid and gas. This can cause pollution and have a direct impact on the surrounding environment, so the waste produced must first be treated before being discharged into the waters. This study aims to determine the level of effectiveness of each ingredient as a natural coagulant as well as the adsorption process in reducing levels of pollutant parameters, including Total Suspended Solid (TSS) and color in the liquid waste of the Jetis Sidoarjo batik industry. The method used is coagulation flocculation. The results of the best combination of green coagulant Moringa seeds pH 8 at a dose of 3500 mg/L, coconut coir pH 6 at a dose of 3500 mg/L, and dry gambas pH 6 at a dose of 3500 mg/L with GAC 50 gr and a sampling time of 60 minutes showed a decrease in the content of TSS parameters. and color respectively TSS 14 mg/L; color 84 Pt-Co, TSS 10 mg/L; color 54 Pt-Co TSS 26 mg/L; color 161 Pt-Co.