Chitosan Coagulation Research Articles

Extraction of Chitosan Derived from Mushroom by Deacetylation for Wastewater Treatment

In this study, Volvariella vovacea (straw mushroom, SM) and Flammulina velutipes (Golden mushroom, GM) were used as a natural source of chitin. The aim of this research is to extract chitin and thus, converted into chitosan via acetylation process. The obtained chitosan was applied in the wastewater treatment process as the coagulant to improve the quality of wastewater. As these two types of mushrooms are readily available in the local area in Northeastern Thailand and relatively cheap. The chitin extraction process was obtained by firstly removing fat, minerals, protein and pigment of SM and GM using petroleum ether, HCl, NaOH and acetone respectively. Extracted chitin was deacetylated by using 50% (v/v) NaOH at 140 oC for 2 hours to convert into chitosan. The properties of extracted chitosan was examined by FT-IR and TGA. FTIR spectrum showed the peaks of C-H stretching at 2870 cm-1 , N-H2 bending at 1586 cm-1, N-H stretching at 1026 cm-1, etc. which corresponded to the standard chitosan. TGA showed the thermal decomposition which is divided into three phases. First stage of weight loss is between 50-115 °C caused by water evaporation. There was no changes of weight during a temperature of 115-268 °C. The second phase during 268-330 °C indicates a significant weight loss which is due tot he saccharide degradation of chitosan and at a temperature more than 330°C refers to the volatile organic material. As a result of TGA, it can be confirmed that the extracted chitosan from SM and GM is very similar to the standard commercial chitosan. After that, 3 g of extracted chitosan was mixed with 300 mL of deionized water and 6 mL of acetic acid was added for 24 hours to prepare the chitosan coagulant. Then, it was dropped in the separate jar which contained high TSS, COD and BOD wastewater. The results showed that chitosan biocoagulant could reduce TSS, COD and BOD by 62, 62 and 88% respectively which proved to be efficient in the use of wastewater treatment.

Penggunaan Jar Test untuk Penentuan Dosis dan Komposisi Optimum Komposit Koagulan Poly Aluminium Chloride (PAC) – Kitosan dalam Menurunkan TSS dan COD

Laundry waste is a pollutant that has pollutant parameters such as TSS and COD. One alternative processing is flocculation-coagulation using synthetic coagulants. The advantage of synthetic coagulants is that they are able to remove high concentrations of pollutants, but the disadvantages are that they produce quite a lot of chemical sludge and the pH of the water becomes acidic because the higher the concentration, the more coagulant is used. Previous research explains that chitosan at low doses has good penyisihan efficiency so that when combined with PAC it is hoped that it can increase penyisihan efficiency with less sludge. The purpose of this study was to determine the optimum dosage and composition for PAC and chitosan coagulant composites using the Jar Test. The Jar Test method for determining the optimum dose uses fast stirring at 140 rpm for 2 minutes and then slow stirring at 60 rpm for 15 minutes and settling for 30 minutes. Determination of the optimum dose by adding a coagulant composite of 300 ppm, 500 ppm, and 700 ppm and by varying the composition at each dose, namely 1:1, 1:3, and 3:1 between PAC-chitosan. The best conditions from the study obtained an optimum dose of 700 ppm and an optimum composition of 3:1 between PAC and chitosan resulting in COD and TSS penyisihan efficiencies of 70.04% and 90.82%.

Densification of Synechococcus subsalsus biomass by chitosan coagulation for biogas production

ABSTRACT This study evaluated the coagulation/flocculation process using chitosan as a natural coagulant to concentrate suspensions of the cyanobacterium Synechococcus subsalsus and enable biogas production from concentrated biomass. The chitosan performance was tested and compared with the inorganic ferric chloride (FeCl3) coagulant. Using the liquid fraction of the coagulation/flocculation process in subsequent biomass cultivations proved viable, with similar growths in culture media with up to 80% of the liquid fraction. At pH 6 and 400 mg/L FeCl3, the biomass concentrated almost seven times, increasing the total suspended solids (TSS) of the suspension from 0.4–0.6 g/L to 2.6–4.0 g/L. With 80 mg/L chitosan and pH 7, the TSS concentration attained values in the range of 7.0–9.7 g/L, an increase of more than 30 times, clearly showing that chitosan has a much higher capacity for biomass concentration at a lower concentration. A ratio of 0.3 g chitosan/g dry mass of the biomass was established to reach the maximum densification. The production of methane from chitosan-densified biomass proved to be feasible. Chitosan-densified biomass showed a two-phase cumulative methane production when digested, with slower methane production and 23% lower methane yield after 30 days of digestion (207 NmL CH4/g CODi) compared to the biomass from cultivation (non-densified, 270 NmL CH4/g CODi). However, optimizing the digestion conditions of the densified biomass should increase the methane yield and reduce process time.

Chitosan coagulant: coagulation/flocculation studies on turbidity removal from aquaculture wastewater by response surface methodology

Chitosan coagulant: coagulation/flocculation studies on turbidity removal from aquaculture wastewater by response surface methodology

Optimization of Reduction TSS (Total Suspended Solid) Levels on Skin Cracker Industrial Waste Using Chitosan Coagulant

Optimization of Reduction TSS (Total Suspended Solid) Levels on Skin Cracker Industrial Waste Using Chitosan Coagulant

Utilization of chicken eggshell and chitosan as coagulants for microplastic removal from aquatic system

Smaller size plastics known as microplastics are harmful for marine biota as well as humans. One of the common methods for the removal of microplastics from water is coagulation. Chicken eggshells and chitosan are two natural ingredients which contain useful content for the coagulation process. Therefore, this paper describes the effect of concentration of eggshells and chitosan as coagulants in the separation of microplastic from water using RSM (Response Surface Methodology). The effect of tannic acid concentration as coagulation aid was also analyzed in this paper. The coagulants were varied with concentration of 1.5-8.5 g/100 mL and tannic acid concentration was 3-17 mg/100 mL. The result of this study showed coagulation with the highest efficiency occurred when 8.5 g/100 mL of chicken eggshell coagulant (89.14%) and 10 g/100 mL chitosan coagulant (75.67%) was added. Optimum operation occurred after the addition of coagulant aid in the amount of 7 mg/100 mL with chicken eggshell and 15 mg/100 mL with chitosan.

Optimization of chitosan coagulant from dry legs of giant freshwater prawn, Macrobrachium rosenbergii in aquaculture wastewater treatment using response surface methodology (RSM)

The environmental impacts of aquaculture wastewater and biowaste from shellfish processing have become a major challenge to aquaculture expansion and sustainability. There is need to develop measures for the wastewater treatment and proper recycling of the biowaste. In this study, dry legs of giant freshwater prawn (Macrobrachium rosenbergii) were chemically processed into chitin and chitosan for use as coagulant in the coagulation/flocculation of real aquaculture wastewater. Box-Behnken design in response surface methodology (RSM) was used to establish the optimum operating conditions of chitosan dosage, pH, and settling time for removal of turbidity and colour. Statistical models were generated for the independent variables after which the model was validated. Results showed that dry legs of M. rosenbergii are mainly composed of minerals (76.36%) with low level of chitin (9.29%) and chitosan (7.02%). With 80% solubility and 91% degree of deacetylation (DDA), the smooth and none porous chitosan showed great potential of a good coagulant. This study recorded that dosage (5 mg/L), pH (5) and settling time of 11.25 min successfully removed 93.84% turbidity while 99.89% colour removal was achieved at 20 mg/L at 7.5 pH and 30 min settling time. The high level of minerals in the legs was responsible for the low chitin and chitosan yields while high turbidity and colour removals were attributed to the solubility and DDA.

Response Surface Methodology (RSM) Approach to Optimization of Coagulation-Flocculation of Aquaculture Wastewater Treatment Using Chitosan from Carapace of Giant Freshwater Prawn Macrobrachium rosenbergii.

The major sources of waste from aquaculture operations emanates from fish or shellfish processing and wastewater generation. A simple technique called coagulation/flocculation utilizes biowaste from aquaculture to produce chitosan coagulant for wastewater treatment. A chemical method was applied in the present study for chitin and chitosan extraction from carapace of Macrobrachium rosenbergii and subsequent application for removal of turbidity and salinity from shrimp aquaculture wastewater. Box-Behnken in RSM was used to determine the optimum operating conditions of chitosan dosage, pH, and settling time, after which quadratic models were developed and validated. Results show that 80 g of raw powder carapace yielded chitin and chitosan of 23.79% and 20.21%, respectively. The low moisture (0.38%) and ash (12.58%) content were an indication of good quality chitosan, while other properties such as water-binding capacity (WBC), fat-binding capacity (FBC), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscope (SEM) confirmed the structure and the α-group, as well as the rough morphology of chitosan. In addition, the high solubility (71.23%) and DDA (85.20%) suggested good coagulant potentials. It was recorded in this study that 87.67% turbidity was successfully removed at 20 mg/L of chitosan dosage and 6.25 pH after 30 min settling time, while 21.43% salinity was removed at 5 mg/L of chitosan dosage, 7.5 pH, and 30 min settling time. Therefore, the process conditions adopted in this study yielded chitosan of good quality, suitable as biopolymer coagulant for aquaculture wastewater treatment.

Emprego de quitosana na remoção de poluentes em efluentes de processamento de pescado

ABSTRACT The significant growth of the industrial sector in recent decades has led to an increase in the volume of waste, which if not properly destined, could cause serious environmental problems. In the context of aquaculture, liquid effluents with a high organic content are generated in large quantities in the fish processing industries, and if their disposal is carried out improperly, serious damage to the environment is caused. The general objective of this study is to evaluate: the efficiency of removal of COD and BOD, in addition to the influence on pH; alkalinity; chlorides; ammonia; nitrite; nitrate; phosphate; turbidity; total, fixed and volatile solids, from the effluent of fish processing treated by coagulation and sedimentation using the natural chitosan coagulant. pH 5.5 followed by pH 6 showed better results for the use of chitosan coagulant in the process of treatment by effluent coagulation of fish processing industry. Chitosan does not act on the parameters TVS, alkalinity, chlorides, ammonia, nitrite, nitrate, and phosphate, regardless of the dosage used. However, it acts on BOD, COD, TS, TFS and turbidity. Thus, the best dosage of chitosan is 0.25 g L-1 in optimized activity at pH of 5.5.

Enhanced removal of extracellular microcystin-LR using chitosan coagulation-ultrafiltration: Performance and mechanisms

Although many studies have proposed different drinking water treatment strategies to cope with harmful algal blooms (HABs), the removal of dissolved cyanotoxins remains a technical challenge. In this study, well-controlled laboratory experiments were performed to investigate the performance of chitosan as an alternative to traditional metallic coagulants in a hybrid coagulation-ultrafiltration (UF) process for addressing multiple HABs impacts in drinking water treatment. Compared to aluminum chlorohydrate (ACH), chitosan induced the formation of much larger and compact flocs, resulting in about 50% of M. aeruginosa cells removal after simple straining. While coagulation with ACH slightly reduced the rate and extent of UF permeate flux decline, chitosan coagulation at low doses (up to 0.25 mg/L) significantly reduced membrane fouling by 33%. At optimal dose (0.25 mg/L), chitosan coagulation showed a remarkable enhancement effect on the extracellular microcystin-LR (MC-LR) removal by UF membrane, up to 50% higher than those achieved with ACH (20%) coagulation and control condition (15%). However, excessive chitosan dosing would lead to severe membrane fouling. Molecular dynamic simulation results confirmed that chitosan exhibited affinity towards MC-LR via electrostatic interactions and weaker yet prevalent hydrogen bonding. The binding between chitosan and MC-LR would lead to toxin encapsulation within the flocs structure and thus an increased level of toxin retention by UF membrane based on the mechanism of size exclusion.

The effect of chitosan (CS) coagulation bath on structure and performance of polylactic acid (PLA) microfiltration membrane

The effect of chitosan (CS) coagulation bath on structure and performance of polylactic acid (PLA) microfiltration membrane

Chitosan Coagulation Pretreatment to Enhance Ceramic Water Filtration for Household Water Treatment.

Viruses are major contributors to the annual 1.3 million deaths associated with the global burden of diarrheal disease morbidity and mortality. While household-level water treatment technologies reduce diarrheal illness, the majority of filtration technologies are ineffective in removing viruses due to their small size relative to filter pore size. In order to meet the WHO health-based tolerable risk target of 10−6 Disability Adjusted Life Years per person per year, a drinking water filter must achieve a 5 Log10 virus reduction. Ceramic pot water filters manufactured in developing countries typically achieve less than 1 Log10 virus reductions. In order to overcome the shortfall in virus removal efficiency in household water treatment filtration, we (1) evaluated the capacity of chitosan acetate and chitosan lactate, as a cationic coagulant pretreatment combined with ceramic water filtration to remove lab cultured and sewage derived viruses and bacteria in drinking waters, (2) optimized treatment conditions in waters of varying quality and (3) evaluated long-term continuous treatment over a 10-week experiment in surface waters. For each test condition, bacteria and virus concentrations were enumerated by culture methods for influent, controls, and treated effluent after chitosan pretreatment and ceramic water filtration. A > 5 Log10 reduction was achieved in treated effluent for E.coli, C. perfringens, sewage derived E. coli and total coliforms, MS2 coliphage, Qβ coliphage, ΦX174 coliphage, and sewage derived F+ and somatic coliphages.

Comparison of the Effectiveness of Natural Coagulant Performance on% BOD Removal and% COD Removal in Pharmaceutical Industry Waste

Waste treatment can be done in variousways. One of the methods that can be used isthe coagulation and flocculation method. Thecoagulant used can be either a chemicalcoagulant or a natural coagulant. Naturalcoagulants can be used in wastewatertreatment for % removal of BOD and %removal of COD. By using moringa seedcoagulant, it showed % removal of BOD of90.12% and % removal of COD in thepharmaceutical industry waste a maximum of71.23%. Through the use of tapioca starchcoagulants, % removal of BOD and CODwas 95.25% and 94.63%. The use of smallcrab chitosan coagulant showed % removalof both BOD and COD’s results was 32%and 31%.

고탁도 건설폐수 처리시스템 개발

Sediment and turbidity from construction sites are primary causes for surface water quality impairment. Much of the sediment leaving construction sites consists of silt an clay that can carry substantial amounts of nutrients and pollutants. Increased turbidity can limit sunlight penetration into water by both adsorbing and deflecting light. Coagulation is the most widely used for microparticle removal in water and wastewater treatment facilities. Coagulants are added to transform dispersed particles into aggregate floc for subsequent removal by sedimentation. Instead of impeller type mixer for coagulation, coagulants injection hydrocyclone and was used for coagulation. Hydrocyclone effluent and underflow are recycled in retention basin for flocculation and settling. To determine the optimum Chitosan dosage for treatment of construction sites high turbidity, tunnel construction site, aggregate extraction sediment, clay-silt soil samples were used for Jar test. Chitosan, obtained by deacetylation of chitin, is described as a cationic polyelectrolyte and is expected to coagulate negatively charged suspended particles found in turbid waters. The structure of Chitosan is very similar to that of cellulose, and is biodegradable. Chitosan coagulants also produced larger flocs of better quality and faster settling velocity, dewatering. Therefore, Chitosan has become necessary to develop more efficient and environment-friendly flocculants for removal of turbidity in waters. As the results of Jar test (rapid mixing 1min, slow mixing 3 min, settling 15 min), the optimum Chitosan dosage was 10~15 mg/L for clay silt soil. Because of the effectiveness of Chitosan in removing turbidity was independent on pH, the hydrocyclone coagulation system would be simple. The results of lab scale retention basin with hydrocyclone coagulation system test indicate that the ranges of removal efficiency of turbidity, SS were 81.5~96.1%, 84.9~95.1%, respectively. Hydrocyclone coagulation system would have possibility with compact design, because of the increase of floc size and reduces the settling time.

Transparent, Aldehyde-Free Chitosan Aerogel

Aldehyde-free, transparent chitosan aerogel is reported. The aerogel was prepared by thermal decomposition of urea to induce gelation of a chitosan solution, followed by solvent exchange to ethanol, and supercritical drying. Low urea concentrations (≤ 25 g L-1) result in transparent and highly mesoporous aerogels, while higher urea concentrations (≥ 30 g L-1) produce opaque, more macroporous aerogels. The high surface areas of > 400 m2 g-1, large mesopore volumes up to 3.5 cm3 g-1, and optical transparency of the low-urea aerogels indicate a high structural homogeneity at the mesoscale, and the properties comparable to previously reported transparent chitosan aerogels prepared with formaldehyde crosslinking. The macroscopic size changes of the wet gels indicate that microstructure formation is controlled by the timing of chitosan coagulation, which depends among others on urea concentration. The aldehyde-free, microstructure-tunable process provides a new series of transparent biopolymer aerogels with "true aerogel" mesoporous structures.

Harvesting of Microcystis flos-aquae using chitosan coagulation: Influence of proton-active functional groups originating from extracellular and intracellular organic matter

Algogenic organic matter (AOM) produced by Microcystis cells inhibits coagulation harvesting; however, the harvesting inhibitory mechanisms at the functional groups level remain to be determined. This study fractionated extracellular organic matter (EOM) and intercellular organic matter (IOM) from Microcystis flos-aquae into five different hydrophilic and hydrophobic fractions and investigated their inhibition of chitosan coagulation harvesting. The proton-active functional groups in the inhibitory fractions were further analysed by potentiometric titration, and the interaction between these functional groups and chitosan was elucidated. The results showed that the harvesting inhibition of M. flos-aquae cells was dominated by HPI in AOM due to its high charge density, which resulted in greater consumption of coagulant. Potentiometric titration results suggested that the proton-active functional groups of both HPIEOM and HPIIOM consist mainly of phosphodiester, carboxylic, phosphoryl and amine/hydroxyl functional groups, and the harvesting inhibition of HPI on M. flos-aquae cells at pH 6.5 was mainly due to the deprotonation of phosphodiester and carboxylic functional groups. Moreover, carboxylic functional groups with stronger polarity could enhance the intermolecular interaction between HPI and chitosan more effectively than phosphodiester at pH 6.5. Preventing the deprotonation of carboxylic functional groups by adjusting the pH to 4.3 could effectively alleviate the harvesting inhibition caused by HPI. These findings revealed the inhibition mechanism of AOM on the coagulation harvesting of M. flos-aquae cells from the perspective of deprotonation of proton-active functional groups, which may provide important insights for assessing the role of AOM in the coagulation harvesting of Microcystis cells.

Mixed culture microalgae removal for water quality improvement using chitosan

The presence of microalgae affects water quality and beneficial uses of surface freshwaters. Chitosan with proven potential for harvesting specific microalgae species from their culture medium to produce biofuels and bioproducts also appears promising for efficient removal of mixed microalgae species from surface freshwaters. The main focus of the present study was on removal of mixed microalgae species using chitosan as a coagulant to help improve water quality. Important operational parameters were optimized for economical microalgae removal. The microalgae cells, chlorophyll-a, total nitrogen, and total phosphorous removal efficiency were 82.06%, 89.90%, 69.32%, and 44.01%, respectively, at an optimum chitosan dose of 10 mg/L, pH 8, slow mixing time 7 min, slow mixing rate 30 rpm, and settling time of 15 min. The results show that chitosan coagulation efficiently removed mixed microalgae species from surface freshwater with significant improvement in water quality and recovery of algal biomass for other beneficial applications.

Progress in Research and Application of Natural Polymer Coagulants

In recent years, natural polymer coagulant has become a hot spot in the field of coagulants due to its safety, harmlessness and biodegradability. This paper introduced the status quo of research of natural polymer coagulants such as starch, chitosan, cellulose and lignin coagulants. And some hot applications in water treatment were discussed, such as heavy metal wastewater, dye wastewater, microalgae collection and sludge dewatering. Finally, the development trend of natural polymer coagulants was prospected.

Potential Application of Biopolymer Chitosan and Cationic/Anionic Polymers in Textile Wastewater Treatment

Biopolymer chitosan have been investigated for color removal in textile wastewater by using coagulation process of biopolymers and synthetic polymers. After the wastewater samples were treated with 0.1% chitosan for chitosan coagulation process, coagulation process of cationic or anionic polymer were performed by using chitosan and cationic polymer (CSC) or chitosan and anionic polymer (CSA) polymer concentrations of 0.1, 0.2 and 0.4 g/l at pH 6-8, respectively. The color removal efficiency of textile wastewater samples before and after treatment with chitosan followed by cationic/anionic polymers has been evaluated. The color removal by chitosan was dependent on pH and the maximum percent removal 31.4 ± 3.3% has been observed at pH 7. The optimum parameters for polymer-biopolymer coagulation process in this study was CSC at dosage of 0.2 g/l, pH 8 and CSA at dosage of 0.1 g/l, pH 7. Besides, its chemical analyses including Chemical Oxygen Demand (COD), dissolved solid, and suspended solid were analyzed in order to consider the potential application of chitosan in textile wastewater treatment. The results showed that the COD, dissolved solid and suspended solid of pre-treated textile wastewater were 290, 3998.7 and 280.7 mg/l, respectively, however, both dissolved solid and suspended solid were higher than the regulatory standard for wastewater. As the optimum condition, the COD, dissolved solid and suspended solid of textile wastewater after treatment with CSC (0.2 g/l at pH 8) were 260.7, 1939.8 and 103.6 mg/l, respectively, while the COD, dissolved solid and suspended solid of textile wastewater after treatment with CSA (0.1 g/l at pH 7) were 190.6, 3002.2and 106.8 mg/l, respectively. All of the results after treatments were within the regulatory standard. Therefore, the combination of chitosan and cationic/anionic polymers could be utilized in textile wastewater treatment.

Effectiveness of biopolymer coagulants in agricultural wastewater treatment at two contrasting levels of pollution

Agricultural diffuse pollution is a major environmental problem causing eutrophication of water bodies. Despite the problem is widely acknowledged, there has been relatively few major advances in mitigating the problem. We studied the effectiveness of biopolymer-based (tannin, starch, chitosan) natural coagulants/flocculants in treatment of two different agricultural wastewaters that differed in their level of phosphorus pollution and turbidity. We used jar-tests to test the effectiveness of the biopolymer coagulants in reducing water turbidity, total phosphorus, and total organic carbon (TOC) from the wastewaters. In more polluted water (total phosphorus: 300 µg/L, turbidity: 130 FNU, TOC: 30 mg/L), all tested biopolymers performed well. The best reductions for different biopolymer coagulants were 64–95%, 80–98% and 14–27%, for total phosphorus, turbidity and TOC, respectively. Tannin and chitosan coagulants performed the best at doses of 5–10 mL/L, whereas starch coagulants had the best performance at 1–2 mL/L doses. Tannin and chitosan coagulants performed clearly better than the starch coagulants. In less polluted water (total phosphorus: 74 µg/L, turbidity: 3.9 FNU, TOC: 21 mg/L), chitosan and starch coagulants did not produce flocs at any of the tested doses. Tannin coagulant performed the best at doses of 5–8 mL/L, where reductions were 70%, 82%, and 22%, for total phosphorus, turbidity and TOC, respectively. The great reductions of phosphorus and turbidity suggests that biopolymer coagulants could be applied in treatment of agricultural water pollution. The high phosphorus retention in the biodegradable biopolymer sludge suggests that the sludge can be readily used as a phosphorus fertilizer, which would aid the recycling of nutrients.