Papers by Keyword: Coagulation

Abstract: The coagulation process of polymer dispersion in cement-based materials is different from that of the pure polymer dispersion during drying and film formation. This process is influenced by the various ions released from cement hydration and the interaction between polymer and cement grain in the water. This paper focuses on the coagulation of polymer dispersion during cement hydrating and the influence on the performances e.g. water absorption, flexural and compressive strength and bonding strength of cement mortar. Commercial anionic styrene-acrylate polymer dispersion was investigated in the coagulation process in the polymer-modified cement paste with polymer to cement ratio (p/c) from 5% to 20% and water to cement ratio of 0.3. The amount of coagulated polymer particles was measured by testing the solid content of the supernatant of the diluted polymer-modified cement paste for a period of time. The calorimetric property was measured by TAM AIR calorimeter. Water absorption and mechanical properties of the modified mortar were also measured according to the China standard. The result showed that the polymer dispersion mixing with cement was found to be coagulated in the very early stage under the low polymer to cement ratio, and the quantity of the polymer particles remained in the liquid is quite low within few minutes during this fast coagulation process. The fast coagulation process undermines the influence of polymer dispersion on the cement hydration and the heat evolution. But it has negative impact on the mechanical properties and water resistance. Adding of surfactant into the polymer dispersion extends the coagulation process and improves these performances.

Abstract: Tar water acquired in the process of biomass gasification has been pre-treated in the process of the standard coagulation. The influence of the dose of chosen coagulants and pH of the running process on the effectiveness of waste water treatment has been specified. The most purified samples underwent a secondary treatment in the process of advanced oxidation with the Fenton's reagent, in order to evaluate its abilities and desirability of this method in the process of a coagulation. The analysis of the process' conditions influence on its effectiveness has been conducted. What is more, the evaluation of the validity of combining the coagulation process with the advanced oxidation in the treatment of tar water coming from the biomass gasification has been made.

Abstract: In this research, a physico-chemical treatment method of coagulation-flocculation process is implemented in treating partially stabilized leachate from Matang Landfill, Perak, Malaysia. Central composite design has been used to optimize the independent variables namely polyaluminum chloride (PAC) coagulant dosage (A), rapid mixing speed (B) and rapid mixing time (C). The experimental results were analyzed by using analysis of variance (ANOVA). The results revealed that the percentage of color and COD removal was found increased by increasing rapid mixing speed with optimum removal of 95 % and 56 % respectively. Besides, the R-squared values implied that 86.22 % and 97.34% of the total variation explained by the model equation. Furthermore, the model analysis revealed that rapid mixing speed were significant for removal of color and COD through single parameter (B) and interaction between parameter (AB) respectively. This finding proves the influence of mixing parameter in coagulation-flocculation process for leachate treatment.

Abstract: Sago starch has been widely used in industrial fields, especially in food, non-food, and animal feed biotechnology. Malaysia is one of the highest local sources of sago starch. The alternative use of sago starch as a coagulant for domestic wastewater treatment was investigated in this study. The wastewater sample was collected from the Juru Regional Sewage Treatment Plant in Juru, Penang. The studied parameters include the chemical oxygen demand (COD), suspended solids, and color. Standard jar test procedures were conducted. The initial operating conditions were 200 rpm for 3 min of rapid mixing, 40 rpm for 30 min of slow mixing, and 30 min of settling. The optimum conditions included a pH of 7 and dosage of 2000 mg/L, with rapid mixing at 100 rpm for 1 min, slow mixing at 20 rpm for 30 min, and 18 min of settling. The removal rate of COD and color at these conditions was 70%. Simultaneously, 82% of SS was also removed. The results indicated that sago starch has good potential to treat domestic wastewater; the coagulant may also efficiently treat other types of wastewater.

Abstract: This study compared the floc and sludge formed during the coagulation of leachate by different types of coagulants. The coagulants tested in this study were Ferric chloride (FC), pre-hydrolyzed iron (PHI), dual coagulant (PHI+TF(tapioca flour)), and composite coagulant (pre mix of PHI and TF (PHITF)). The floc and sludge were characterized by measuring the sludge volume index (SVI), sludge velocity (SV), and floc size. Results showed that the hierarchy for SVI, SV, and floc size were FC>PHI>PHI+TF>PHITF, PHITF>PHI+TF>PHI>FC, and PHI+TF>PHITF>PHI>FC, respectively. PHITF demonstrated the lowest SVI and the shortest sludge settling time among the tested coagulants. PHI+TF produced the largest floc size. The addition of TF in PHI as a composite and dual coagulant significantly improved the floc and sludge characteristics. PHITF improved the floc and sludge formation of partially stabilized leachate.This study compared the floc and sludge formed during the coagulation of leachate by different types of coagulants. The coagulants tested in this study were Ferric chloride (FC), pre-hydrolyzed iron (PHI), dual coagulant (PHI+TF(tapioca flour)), and composite coagulant (pre mix of PHI and TF (PHITF)). The floc and sludge were characterized by measuring the sludge volume index (SVI), sludge velocity (SV), and floc size. Results showed that the hierarchy for SVI, SV, and floc size were FC>PHI>PHI+TF>PHITF, PHITF>PHI+TF>PHI>FC, and PHI+TF>PHITF>PHI>FC, respectively. PHITF demonstrated the lowest SVI and the shortest sludge settling time among the tested coagulants. PHI+TF produced the largest floc size. The addition of TF in PHI as a composite and dual coagulant significantly improved the floc and sludge characteristics. PHITF improved the floc and sludge formation of partially stabilized leachate.

Abstract: The aim of this research was to find the efficiency ways to treat wastewater from dye tie dye technique by using an effective wastewater treatment system and find out how to implant the technology of the waste water treatment system to help the problems of the community activities which the tie-dye fabric were the major product of their area. The wastewater from the tie-dye industry were collected and were treated with physical, chemistry and biological treatment by using local materials such as sea shell, alum and clay in a laboratory scale. The data from the treatment were used in the designing the small scale water treatment and apply to the study area. Moreover, the treatment technique knowledge will transfer to the community and establish guidelines for community Wastewater treatment. The COD of wastewater from the dying materials of Bark of Xylocarpus granatum, Bark of Sea almond and Bark of Ebony tree seed were 479.2, 428.5, and 564.2 mg/l, respectively. The water quality were improved better up to 83.61% after were treated with the treatment technique. The satisfaction of the community that participate in the training, technology transfer and adoption of guidelines for therapists to use in the community were found that 86 percent had gained the knowledge in wastewater treatment, 95 percent were satisfied and 85 percent of knowledge were benefit to the community, respectively.

Abstract: The effectiveness of combined coagulation and Fenton oxidation to pharmaceutical plant wastewater was investigated under different operational conditions such as pH, dosage, coagulants and ratio of Fe²⁺ to H₂O₂. Among the nonionic polyacrylamide, cationic polyacrylamide, anionic polyacrylamide, polyaluminum chloride and polymeric ferric sulfate, anionic polyacrylamide showed the best efficiency of coagulation for the pharmaceutical plant wastewater. The results also showed that after the combined coagulation and Fenton oxidation treatment, the COD and color were reduced by 69.9% and 78.9%, respectively. The BOD₅/ COD ratio increased from 0.09 in initial to 0.22 after treatment. The wastewater of outlet was easier for the sequent biological process.

Abstract: The experimental treatment of emulsifying wastewater containing fluo- rescent permeating agent is conducted using demulsification, flocculation, sedimentation and Fenton processes. The experimental results show that, under the appropriate conditions, the COD, oil and chromaticity can be removed efficiently. The pH, COD, oil and chromaticity of the outwater can reach the national standards.

Abstract: The amount of hair dye wastewater largest stage formed by oxidative hair dye in terms of quantity and quality, there is a serious pollution problem in the aquatic environment. Through analysis of the main component of hair dye to verify the use of activated carbon adsorption - Coagulation - potassium permanganate oxidation technology of wastewater treatment which is effective measures.According to different types of hair dye,about 80% of the market demand oxidative hair dye brown was selected to study. The results showed that the COD of 2427mg / L, the chromaticity of the hair 1000 times wastewater using 1300mg / L activated carbon adsorption treatment alone, the removal rates were 37.79%, 18.29%; in this condition and 140mg / L of mixed PAC condensate combined treatment, removal rates were 90.09%, 90.56%; potassium permanganate solution 70mg / L continues oxidation treatment, the removal rate reached 90.34 %, 97.37 %.

Abstract: It is difficult to be degraded by biological process for some oil-produced wastewater containing high content of oil, salt, and COD. The combined process including advanced oxidation was adopted to handle it in this paper. The combined process including adsorption by furnace ash, coagulation by complex of ferro-aluminum salt, Fenton advanced oxidation, alkali out by NaOH and Fenton secondary oxidation was determined. Considering both the treatment effect and the cost, the optimizing process is as follows, the slurry of ferro-aluminum complex salt of 9% (m/m) was as a coagulant with a dosage of 0.8% (v/v); pH value of 3.2,Fe²⁺/H₂O₂ of 1/2.5(v:v) and 30 mmol/L dosage of FeSO₄⋅7H₂O was confirmed in advanced oxidation phase; NaOH was as precipitant with a dosage of 1%(m/m); Finally, after the secondary oxidation, the COD value greatly dropped from original 5 422 mg/L of raw oil-produced wastewater to 185.3 mg/L of effluent with a removal as high as 96.6%. It meets the national discharge standard on oil-produced wastewater. BOD₅ / COD also rose from 0.23 to 0.39 which indicated an improved biochemical property.