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In this study, hydrogen (H

Magnetic porous water hyacinth-derived biochar (MPBCMW3) was synthesized via two-step Microwave (MW)-assisted processes. Characterization results not only testified high specific surface area (2097.50 m2/g) of the MPBCMW3 assisted by MW-assisted pyrolysis, but also revealed its favorable magnetism derived from MW-assisted hydrothermal process. The MPBCMW3 possessed pH-dependent monolayer adsorption capacities of 202.61 and 202.62 mg/g for Cr(VI) and TC with quick attainments of uptake equilibrium within 150 and 200 min. Moreover, the Cr(VI) and TC uptake were substantially steady under the interference from multifarious co-existing ions with slight decline after three adsorption–desorption cycles. Furthermore, the MPBCMW3 was demonstrated to achieve excellent Cr(VI) binding primarily through complexation, electrostatic interaction, reduction and ion exchange, while presenting outstanding TC removal via pore filling, π-π stacking, hydrogen bonding force, electrostatic interaction and complexation. All these findings suggested the MPBCMW3 synthesized by MW-assisted processes as an excellent adsorbent for purification of Cr(VI) and TC-contaminated water.

This review is focused on the sustainable management of harvested water hyacinth (WH) via thermochemical conversion to carbonaceous materials (CMs), biofuels, and chemicals for energy and environmental applications. One of the major challenges in thermochemical conversion is to guarantee the phytoremediation performance of biochar and the energy conversion efficiency in biowaste-to-energy processes. Thus, a circular sustainable approach is proposed to improve the biochar and energy production. The co-conversion process can enhance the syngas, heat, and energy productions with high-quality products. The produced biochar should be economically feasible and comparable to available commercial carbon products. The removal and control of heavy and transition metals are essential for the safe implementation and management of WH biochar. CMs derived from biochar are of interest in wastewater treatment, air purification, and construction. It is important to control the size, shape, and chemical compositions of the CM particles for higher-value products like catalyst, adsorbent or conductor.

Phytoremediation, the application of vegetation and microorganisms for recovery of nutrients and decontamination of the environment, has emerged as a low-cost, eco-friendly, and sustainable approach compared to traditional biological and physico-chemical processes. Livestock wastewater is one of the most severe pollution sources to the environment and water resources. When properly handled, livestock wastewater could be an important alternative water resource in water-scarce regions. This review discussed the characteristics and hazards of different types of livestock wastewater and available methods for the treatment. Meanwhile, the current status of investigations on phytoremediation of livestock wastewater via different hydrophyte systems such as microalgae, duckweed, water hyacinth, constructed wetlands, and other hydrophytes is reviewed, and the utilization of hydrophytes after management is also discussed. Furthermore, advantages and limitations on livestock wastewater management via phytotechnologies are emphasized. At last, future research needs are also proposed.

In this work, hydrothermal liquefaction experiments of iron impregnated water hyacinth were performed with a motive to enhance bio-oil yields along with generation of nanometal carbon hybrids. Iron nanoparticles were impregnated and its metal loading was determined by ICP-MS. The impact of operating parameters like temperature, biomass to water ratio and reaction time on bio-oil yields was studied. During hydrothermal liquefaction a maximum total bio-oil yield of 38.1% was obtained at 280 °C along with formation of nanometal carbon hybrids. The light oil and heavy oil fractions were characterized by GCMS and NMR for determining the key components. The light oil mainly comprises of alkanes, alcohols and esters whereas heavy oil contains esters, ethers, carboxylic acids and phenols. XRD and XPS of Fe-impregnated water hyacinth and residues confirmed the transition of Fe+3/+2 to Fe0. TEM analysis resulted an average particle size of Fe nanoparticles around 19.6 nm.

The co-hydrothermal carbonization (co-HTC) of water hyacinth (WH) and polyvinyl chloride (PVC) was investigated and the response surface methodology, which could deduce the interactions among process parameters and establish reliable mathematical models forecasting the behavior of output variables, was implemented to optimize process parameters, including reaction temperature (200–260 °C), residence time (30–90 min) and WH/PVC mixing ratios (0.5–2). Statistical analysis revealed that reaction temperature was the predominant parameter affecting hydrochar dechlorination efficiency, yield, calorific value, energetic recovery efficiency and electricity consumption. The predicted condition of 200-30-0.5 could simultaneously acquire the optimal energetic recovery efficiency and electricity consumption for producing unit HHV, corresponding to 94.96% and 13.81. The characterization results identified that hydrochar could harvest lower H/C and O/C ratios as well as superior inorganics removal ability. Overall, the co-HTC of WH and PVC could definitely be a promising alternative to bridge the gap from solid wastes to renewable fuels.

Catalytic co-pyrolysis of water hyacinth and scrap tire experiments were performed to evaluate the feasibility of improving the monocyclic aromatic hydrocarbons production. The production of monocyclic aromatic hydrocarbons increased from 5.31% (sole pyrolysis of water hyacinth) to 13.11% (co-pyrolysis with scrap tire). With use of zeolites, the highest production of monocyclic aromatic hydrocarbons can reach up to 69.18%. Comprehensive comparison on catalytic effects of HZSM-5 and multilamellar MFI nanosheets were provided. With the material to multilamellar MFI nanosheets ratios changes from 2:1 to 1:4, the production of monocyclic aromatic hydrocarbons increases significantly from 37.15–69.18%. The average production of monocyclic aromatic hydrocarbons produced by using multilamellar MFI nanosheets were 12.07% higher than that using HZSM-5, indicating the better performance of multilamellar MFI nanosheets in producing monocyclic aromatic hydrocarbons. This work provided a reference for the reuse of water hyacinth and scrap tire over multilamellar MFI nanosheets in energy field.

In this study, a novel nitrogen-doped biochar oxygen reduction reaction cathode-water hyacinth carbon, was prepared by ZnCl2 molten salt carbonization without additional nitrogen source, which displayed a high performance in electro-Fenton (E-Fenton) process. The BET result shows that water hyacinth carbon achieved a much larger specific surface area (829 m2·g−1) than non-melt salt carbonized one (323 m2·g−1) and graphite powder (28 m2·g−1). Furthermore, characterization by XPS and EIS shows that both pyridinic-N (43.24%) and graphitic-N (56.75%) existed in water hyacinth carbon and Warburg constant was only 0.051. Because of a high H2O2 producing yield 1.7 mmol·L−1 and corresponding current efficiency 81.2 ± 2.5% in molten salt carbonized water hyacinth biochar, a high kinetic constant 0.318 min−1 in DMP degradation was achieved, which was 4 times higher than graphite powder (0.076 min−1). The TOC removal achieved 86.8% in 30 min and the corresponding energy consumption reached a low level 60.15 kW·h·kgTOC−1.

Water hyacinth (WH), is one of the world's most intractable and invasive weed species. Recent studies explored the efficacy of this species as a biochar (BC) in improving soil fertility and metal adsorption. However, the soil water retention (SWR) property and crack potential of soil-WH biochar composite has still not been studied. The major objective of this study is to investigate the SWR property and corresponding crack intensity factor (CIF) for compacted soil-WH BC composites. Soil-WH BC composites at five percentages (0, 2, 5, 10 and 15) was compacted and soil parameters such as suction (ψ), water content and CIF were simultaneously monitored for 63 days (including 9 drying-wetting cycles). Results showed that soil-WH BC composite at all percentages retains more water (max. 19% and min. 6.53%) than bare soil at both saturated and drought conditions. Gradual inclusion of WH BC to soil decreases the CIF potential from 7% to 2.8%.

International audience; The aim of this study is to assess the potentials of using mixed culture bacteria incorporated with different concentrations of NaHCO3 for hydrogen production from water hyacinth (WH). The lowest hydrogen yield (HY) of 30.4 ± 1.9 mL/gTVS, H2 content (HC) of 19.5 ± 1.5% and hydrogenase enzyme (HE) activity of 0.06 ± 0.01 mgM.Breduced/min were registered for the cultures without supplementation of NaHCO3. The HY, HC, and HE activity were maximized at levels of 69.2 ± 4.3 mL/gTVS 58.4 ± 3.6% and 0.18 ± 0.01 mgM.Breduced/min. respectively for the anaerobes supplied with 3.0 g NaHCO3/L. Furthermore, cellulose, hemicellulose, and lignin destruction efficiencies were 37.2 ± 2.3, 30.0 ± 1.9 and 20.9 ± 1.3% respectively due to the increase of cellulase and xylanase activities up to 2.73 ± 0.17 and 1.87 ± 0.12 U/mL, respectively. Moreover, the abundance of Firmicutes was substantially increased and accounted for 71% of the total OTU's. Microbes belonging to the order Clostridiales and OPB54 were particularly enriched in the medium supplemented with NaHCO3. © 2018 Elsevier Ltd

A complex of water-hyacinth derived pellets immobilized with Chlorella sp. was applied, for the first time, in the bioremediation of Cadmium (Cd). The Cd(II) removal efficiency of the complex was optimized by investigating several parameters, including the pellet materials, algal culture age, and light intensity. Results showed that the Cd(II) removal efficiency was positively related to the algal immobilization efficiency and the algal bioaccumulation capacity. Since higher surface hydrophilicity leads to higher immobilization efficiency, the water-hyacinth leaf biochar pellet (WLBp) was selected as the optimal carrier. A maximum Cd(II) removal efficiency of 92.45% was obtained by the complex of WLBp immobilized with algal cells in stationary growth phase and illuminated with a light intensity of 119 μmol m−2 s−1. Recovery tests on both microalgal cells and the WLBp demonstrated that the algal cells and the biochar pellet can be economically recycled and reused.

This study investigated the possibility of enhancing bioethanol production by combined pretreatment methods for water hyacinth. Three different kinds of pretreatment methods, including microbial pretreatment, microbial combined dilute acid pretreatment, and microbial combined dilute alkaline pretreatment, were investigated for water hyacinth degradation. The results showed that microbial combined dilute acid pretreatment is the most effective method, resulting in the highest cellulose content (39.4 ± 2.8%) and reducing sugars production (430.66 mg·g−1). Scanning Electron Microscopy and Fourier Transform Infrared Spectrometer analysis indicated that the basic tissue of water hyacinth was significantly destroyed. Compared to the other previously reported pretreatment methods for water hyacinth, which did not append additional cellulase and microbes for hydrolysis process, the microbial combined dilute acid pretreatment of our research could achieve the highest reducing sugars. Moreover, the production of bioethanol could achieve 1.40 g·L−1 after fermentation, which could provide an extremely promising way for utilization of water hyacinth.

Effects of the three metal carbonates (K2CO3, Na2CO3, and MgCO3) were quantified on catalytic co-combustion of the sewage sludge and water hyacinth (SW) blend using a thermogravimetric-mass spectrometric (TG-MS) analysis and kinetics modeling. The main dominating steps of the catalysts were the organic volatile matter release and combustion stage. Weighted mean values of activation energy (Em) were estimated at 181.18 KJ·mol−1, 199.76 KJ·mol−1, 138.76 KJ·mol−1, and 177.88 KJ·mol−1 for SW, SW + 5% K2CO3, SW + 5% Na2CO3, and SW + 5% MgCO3, respectively. The lowest Em occurred with SW + 5% Na2CO3. Overall, catalyst effect on co-combustion appeared to be negligible as indicated by Gibbs free energy ( Δ G ) . The normalized intensities of SW + MgCO3 were strongest. The addition of Na2CO3 and MgCO3 to SW increased flue gases emissions (CO2, NO2, SO2, HCN, and NH3) of SW, whereas the addition of K2CO3 to SW reduced flue gases emissions from the entire combustion process.

Pyrolysis of azolla, sargassum tenerrimum and water hyacinth were carried out in a fixed-bed reactor at different temperatures in the range of 300-450°C in the presence of nitrogen (inert atmosphere). The objective of this study is to understand the effect of compositional changes of various aquatic biomass samples on product distribution and nature of products during slow pyrolysis. The maximum liquid product yield of azolla, sargassum tenerrimum and water hyacinth (38.5, 43.4 and 24.6wt.% respectively) obtained at 400, 450 and 400°C. Detailed analysis of the bio-oil and bio-char was investigated using 1H NMR, FT-IR, and XRD. The characterization of bio-oil showed a high percentage of aliphatic functional groups and presence of phenolic, ketones and nitrogen-containing group. The characterization results showed that the bio-oil obtained from azolla, sargassum tenerrimum and water hyacinth can be potentially valuable as a fuel and chemicals.

This study investigated the possibility of enhancing the disruption of water hyacinth (WH) in an ultrasound-ionic liquid (US-IL) pretreatment assisted by sodium dodecyl sulfate (SDS). 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) was used to dissolve the WH. The optimum concentration of SDS for the highest production of reducing sugar was also determined. Compared to the US-IL pretreatment, the production of reducing sugars, cellulose conversion and delignification were increased by 72.23%, 58.74% and 21.01%, respectively, upon addition of 0.5% SDS. Moreover, the enhancement of SDS in the US-IL pretreatment was confirmed by the analysis of structural features, which demonstrated that the SDS increased the removal of lignin and decreased the cellulose crystallinity.

This study investigates the use of electrohydrolysis pretreatment on water hyacinth to cut short the hydrolysis step and increase biogas production at the same time. Electrohydrolysis pretreatment of water hyacinth at 20V for 60min exhibited improved solubilisation (42.9%). Therefore, bio-chemical methane potential (BMP) test was carried out between water hyacinth pretreated at 20V for 60min and untreated water hyacinth. By the end of 30days, cumulative methane production of 2455±17mL CH4/g VS for electrohydrolysis pretreated substrate and 1936±27mL CH4/g VS for the untreated substrate was achieved. Compositional analysis and characterization study revealed the efficiency of electrohydrolysis pretreatment in melting the lignin and lowering the cellulose crystallinity of water hyacinth.

Water hyacinth a fresh water aquatic plant is considered as a noxious weed in many parts of the world since it grows very fast and depletes nutrients and oxygen from water bodies adversely affecting the growth of both plants and animals. Hence conversion of this problematic weed to value added chemicals and fuels helps in the self-sustainability especially for developing countries. The present review discusses the various value added products and fuels which can be produced from water hyacinth, the recent research and developmental activities on the bioconversion of water hyacinth for the production of fuels and value added products as well as its possibilities and challenges in commercialization. (C) 2017 Elsevier Ltd. All rights reserved.

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In this work, the power and duration time of microwave pretreatment effects on water hyacinth were the main research objects. Surface structure of water hyacinth was broke by microwave radiation through Scanning Electron Microscope observation and the characteristics of thermal decomposition of water hyacinth with the catalyst under four heating rates was investigated by using the thermogravimetric analyzer. Calcium oxide was chosen to be the additive of the water hyacinth pyrolysis reaction. Pyrolysis product compositions were figured out by Pyrolysis-Gas Chromatography/Mass Spectrometry. The results showed that microwave changed the product composition effectively. Under optimal conditions, acids yield of water hyacinth decreased from 7.89% to 4.89% and the yield of sugars increased from 2.73% to 9.04%. Kinetic parameters were calculated by Flynn-Wall-Ozawa method. Under microwave pretreatment at 329 W and 567 W, the activation energy of water hyacinth first decreased and then rose with duration time increasing.

Thermodynamics and kinetics of sewage sludge (SS) and water hyacinth (WH) co-combustion as a blend fuel (SW) for bioenergy production were studied through thermogravimetric analysis. In CO2/O2 atmosphere, the combustion performance of SS added with 10–40 wt.% WH was improved 1–1.97 times as revealed by the comprehensive combustion characteristic index (CCI). The conversion of SW in different atmospheres was identified and their thermodynamic parameters ( Δ H , Δ S , Δ G ) were obtained. As the oxygen concentration increased from 20% to 70%, the ignition temperature of SW decreased from 243.1 °C to 240.3 °C, and the maximum weight loss rate and CCI increased from 5.70%·min−1 to 7.26%·min−1 and from 4.913%2·K−3·min−2 to 6.327%2·K−3·min−2, respectively, which corresponded to the variation in Δ S and Δ G . The lowest activation energy (Ea) of SW was obtained in CO2/O2 = 7/3 atmosphere.

An oxidized biochar was prepared using long-root Eichhornia crassipes through an aerobic/anaerobic hybrid calcination to recycle its waste plants after eutrophic treatments. The adsorption performances of the biochar were investigated and the results showed that the adsorption equilibrium could arrive in 30 min and the adsorption capacities for Pb2+, Cu2+, Cd2+ and Zn2+ at 30 °C were 0.57, 0.41, 0.44 and 0.48 mmol/g, respectively. The adsorption could be promoted at higher pH and temperature and the adsorption tolerance for different heavy metal ions to the existence of competing ions and organic matters was hierarchical. The adsorption was deduced to be heterozygous courses and mainly controlled by complexation of oxygen-containing groups with these heavy metal ions. It was confirmed that the biochar could be regenerated with HCl solution and the adsorption performance kept consistent in 10 adsorption–desorption cycles.

The aim of the study was to explore the role of volatile fatty acids in batch scale anaerobic digestion of two potential aquatic weeds (water hyacinth and salvinia), as substrates for anaerobic digestion. Inoculum (cow dung) to biomass (aquatic weeds) ratio of 0.25:1, 0.5:1, 1:1 and 3:1 were taken and monitored in a 2 L digester for 30 days. The maximum amount of biogas produced for was 406 L kg−1 VS for water hyacinth in 0.5:1 and 330 L kg−1 VS for salvinia in 1:1 and 3:1 ratio for both. The total VFA for water hyacinth and salvinia were 410 mgL−1 & 365 mg L−1, 424 mg L−1 & 316 mg L−1, 272 mg L−1 & 234 mg L−1 and 158 mg L−1 & 94 mg L−1 in 0.25:1, 0.5:1, 1:1 and 3:1 ratios respectively. Multiple linear regression was performed to find the relationship between the methane from biogas, total VFA, acetic acid and propionic acid for enhanced biogas production. It was observed that total VFA significantly influenced methane content in 1:1 (SC) and 3:1 (WC).

Microwave-heated alkali pretreatment (MAP) was investigated to improve enzymatic digestibility and H 2 /CH 4 production from water hyacinth. SEM revealed that MAP deconstructed the lignocellulose matrix and swelled the surfaces of water hyacinth. XRD indicated that MAP decreased the crystallinity index from 16.0 to 13.0 because of cellulose amorphisation. FTIR indicated that MAP effectively destroyed the lignin structure and disrupted the crystalline cellulose to reduce crystallinity. The reducing sugar yield of 0.296 g/gTVS was achieved at optimal hydrolysis conditions (microwave temperature = 190 °C, time = 10 min, and cellulase dosage = 5 wt%). The sequentially fermentative hydrogen and methane yields from water hyacinth with MAP and enzymatic hydrolysis were increased to 63.9 and 172.5 mL/gTVS, respectively. The energy conversion efficiency (40.0%) in the two-stage hydrogen and methane cogeneration was lower than that (49.5%) in the one-stage methane production (237.4 mL/gTVS) from water hyacinth with MAP and enzymatic hydrolysis.

Thermal and catalytic hydrothermal liquefaction of water hyacinth was performed at temperatures from 250 to 300 °C under various water hyacinth:H2O ratio of 1:3, 1:6 and 1:12. Reactions were also carried out under various residence times (15-60 min) as well as catalytic conditions (KOH and K2CO3). The use of alkaline catalysts significantly increased the bio-oil yield. Maximum bio-oil yield (23 wt%) comprising of bio-oil1 and bio-oil2 as well as conversion (89%) were observed with 1N KOH solution. (1)H NMR and (13)C NMR data showed that both bio-oil1 and bio-oil2 have high aliphatic carbon content. FTIR of bio-residue indicated that the usage of alkaline catalyst resulted in bio-residue samples with lesser oxygen functionality indicating that catalyst has a marked effect on nature of the bio-residue and helps to decompose biomass to a greater extent compared to thermal case.

In the present study, a novel concurrent process of pretreatment and wet storage was developed and investigated by applying calcium peroxide for preservation and conversion of fresh water hyacinth biomass to fermentable sugars. The effects of CaO2 loading concentration and moisture content on the lignin reduction, carbohydrate preservation and enzymatic saccharification of water hyacinth biomass were evaluated by experimental design using a response surface methodology. The data showed that the concurrent process could conserve 70% carbohydrates and remove 40% lignin from biomass of water hyacinth at the best condition in this study. The enzymatic digestibility and reducing sugar yield from the best condition of concurrent process were around 93% and 325mg/g (dry weight) of fresh biomass, respectively. The result suggested that the concurrent process developed in this work could be a potential alternative to consolidate the pretreatment and storage of aquatic plant biomass for fermentable sugar production.

The aim of this study was to test practical solutions to improve biogas yield during the anaerobic digestion of water hyacinth (WH) biomass. Increasing the WH (whole plant) solid content to ∼40% through sun drying (6 h), and its subsequent digestion increased biogas yield by 14% with a higher biogas methane (75%) content. Ensilation of dried WH (40% moisture) was found effective for its preservation to ensure its continuous availability even during offseasons, but the biogas yield from six months ensilated biomass was 20% less compared with fresh WH. Co-digestion of WH with waste activated sludge and food waste revealed ∼150 and ∼400 ml biogas/g VS respectively against ∼140 ml/g VS of WH alone. The practical approaches tested in this study like pre-treatment, preservation, and co-digestion of WH found to be effective to make its bio methanation more feasible.

A 15 N labeling technique was used to study nitrogen transfer from cyanobacterium Microcystis aeruginosa to water hyacinth. 15 N atom abundance in M. aeruginosa peaked (15.52%) after cultivation in 15 N-labeled medium for 3 weeks. Over 87% of algal nitrogen was transferred into water hyacinth after the 4-week co-cultivation period. The nitrogen quickly super-accumulated in the water hyacinth roots, and the labeled nitrogen was re-distributed to different organs (i.e., roots, stalks, and leaves). This study provides a new strategy for further research on cyanobacterial bloom control, nitrogen migration, and nitrogen cycle in eutrophic waters.

For the purpose of safe disposal of biomass contaminated by biosorption of heavy metals, phosphate-assisted pyrolysis of water hyacinth biomass contaminated by lead (Pb) was tried to reduce the bioavailability and leaching potential of Pb, using direct pyrolysis without additive as a control method. Direct pyrolysis of the contaminated biomass at low temperatures (300 and 400°C) could reduce the bioavailability of Pb, but the leaching potential of Pb was increased with the rising pyrolysis temperature. While phosphate-assisted pyrolysis significantly enhanced the recovery and stability of Pb in the char. Specifically, the percentages of bioavailable Pb and leachable Pb in the chars obtained by phosphate-assisted pyrolysis at low temperatures were reduced to less than 5% and 7%, respectively. The sequential extraction test indicated the transformation of Pb into more stable fractions after phosphate-assisted pyrolysis, which was related to the formation of Pb phosphate minerals including pyromorphite and lead-substituted hydroxyapatite.

The effect of the pretreatment of water hyacinth with ionic liquid and co-solvent on the lignocellulosic composition, structural change and biogas production was evaluated in this study. The results from regenerated water hyacinth indicate that, the content of the lignocellulosic composition was changed, the crystallinity of the structure was decreased, and the surface became more porous. After the pretreatment with 1-N-butyl-3-methyimidazolium chloride ([Bmim]Cl)/dimethyl sulfoxide (DMSO) under 120 °C for 120 min, the cellulose content of regenerated water hyacinth was increased by 27.9%, 49.2% of the lignin was removed, and the biogas yield was increased by 97.6% as compared with unpretreated water hyacinth. The ionic liquids and co-solvents were successfully recovered by forming aqueous biphasic systems with K3PO4.

The aim of this work was to study the effect of four different types of thermal pretreatment techniques i.e., hot air oven, microwave, autoclave and hot water bath on the hydrolysis, compositional analysis and characterization of water hyacinth. To determine the most efficient thermal pretreatment technique exhibiting enhanced solubilisation. Highest solubilisation was achieved by hot air oven (55.5%), followed by microwave, hot water bath and autoclave. Bio-chemical methane potential (BMP) test of hot air oven pretreated and untreated water hyacinth was conducted. Cumulative methane production of 3039±32mLCH4/gVS was achieved by hot air oven pretreated water hyacinth at 90°C for 1h which was way higher than the cumulative methane production of untreated water hyacinth 2396±19mLCH4/gVS on the 35th day. Compositional analysis and characterization of water hyacinth were also investigated to study the changes in the pretreated samples.

Eichhornia crassipes (EC, water hyacinth) has gained attention due to its alarming reproductive capacity, which subsequently leads to serious ecological damage of water in many eutrophic lakes in the world. The traditional mechanical removal methods have disadvantages. They squander this valuable lignocellulosic resource. Meanwhile, there is a bottleneck for the subsequently reasonable and efficient utilization of EC biomass on a large scale after phytoremediation of polluted water using EC. As a result, the exploration of effective EC utilization technologies has become a popular research field. After years of exploration and amelioration, there have been significant breakthroughs in this research area, including the synthesis of excellent EC cellulose-derived materials, innovative bioenergy production, etc. This review organizes the research of the utilization of the EC biomass among several important fields and then analyses the advantages and disadvantages for each pathway. Finally, comprehensive EC utilization technologies are proposed as a reference.

This study has assessed four invasive weeds, viz. Saccharum spontaneum (SS), Mikania micrantha (MM), Lantana camara (LC) and Eichhornia crassipes (EC) for enzymatic hydrolysis prior to bioalcohol fermentation. Enzymatic hydrolysis of pretreated biomasses of weeds has been conducted with mechanical agitation and sonication under constant (non-optimum) conditions. Profiles of total reducible sugar release have been fitted to HCH-1 model of enzymatic hydrolysis using Genetic Algorithm. Trends in parameters of this model reveal physical mechanism of ultrasound-induced enhancement of enzymatic hydrolysis. Sonication accelerates hydrolysis kinetics by ∼10-fold. This effect is contributed by several causes, attributed to intense micro-convection generated during sonication: (1) increase in reaction velocity, (2) increase in enzyme-substrate affinity, (3) reduction in product inhibition, and (4) enhancement of enzyme activity due to conformational changes in its secondary structure. Enhancement effect of sonication is revealed to be independent of conditions of enzymatic hydrolysis - whether optimum or non-optimum.

This study investigated the pretreatment performance of surfactant-free ionic liquid microemulsions (ILMs) on water hyacinth. Pretreatment effects were evaluated in terms of lignocellulosic composition, structure and enzymatic hydrolysis. Analysis of the regenerated water hyacinth indicated that the content of the lignocellulosic composition changed, and the surface became more porous. After being pretreated with ILM(a) (mass ratio of toluene: ethanol: 1-ethyl-3-methylimidazolium acetate ([Emim]Ac)=0.35:0.3:0.35) at 70°C for 12h, the maximum delignification of 63.6% was observed. The cellulose of the water hyacinth was well protected and retained during the pretreatment process. After being enzymatically hydrolyzed for 48 h, the reducing sugar yield of the water hyacinth pretreated with ILM(a) at 70°C for 6 h was 563.7 mg/g, and its hydrolysis yield (86.1%) was nearly four and a half times of that of the untreated one (20.2%). In conclusion, the designed surfactant-free ILMs exhibit promising potential application in biomass pretreatment.

Rapid pyrolysis of two types of aquatic biomass (blue-green algae and water hyacinth), and their blends with two coals (bituminous and anthracite) was carried out in a high-frequency furnace. Nitrogen conversions during rapid pyrolysis of the two biomass and the interactions between the biomass and coals on nitrogen conversions were investigated. Results show that little nitrogen retained in char after the biomass pyrolysis, and NH 3 yields were higher than HCN. During co-pyrolysis of biomass and coal, interactions between biomass and coal decreased char-N yields and increased volatile-N yields, but the total yields of NH 3 + HCN in volatile-N were decreased in which HCN formations were decreased consistently, while NH 3 formations were only decreased in the high-temperature range but promoted in the low-temperature range. Interactions between blue-green algae and coals are stronger than those between water hyacinth and coal, and interactions between biomass and bituminous are stronger than those between biomass and anthracite.

The present work was aimed at studying the efficiency of the combined process of biofiltration with ozonation to improve the quality of secondary effluent. The secondary effluent from the Dinapur Sewage Treatment Plant Varanasi, India was used in this work. The process of biofiltration with the plant species of Eichornia crassipes and Lemna minor, at a flow rate of 262 ml min(-1) and plant density of 30 mg L(-1) for 48 h, in combination with the process of ozonation with ozone dose of 10 mg L(-1) and contact time of 5 min was applied. Results revealed that combined process was statistically most suitable for the highest degradation of physico-chemical and microbial parameters with improving BDOC value. The biofiltration process is able to remove highest percentage of toxic heavy metals from the secondary effluent without production of toxicity. This technique is highly recommendable for tropical wastewater where sewage is mixed with industrial effluents.

The kinetics of water hyacinth decomposition using pyrolysis and hydrothermal treatment was compared. With pyrolysis, initial vaporization occurred at 453. K as determined by thermogravimetric analysis, while initial solubilisation occurred at 433. K with subcritical hydrothermal treatment. The "kinetic triplet" was determined for the ranges of 423-483. K (range I) and 473-553. K (range II) using the Coats-Redfern method for both treatments. The calculated activation energies for ranges I and II were 110 and 116 kJ/mol for conventional pyrolysis and 145 and 90 kJ/mol for hydrothermal treatment. The similar activation energies for the two temperature ranges observed for pyrolysis implied that only hemicellulose decomposition occurred. For hydrothermal treatment, both hemicellulose and cellulose decomposition occurred in temperature range II, in which a notable lower activation energy was observed. This implied hydrothermal treatment was more suitable for conversion lignocellulosic biomass under these conditions.

A comprehensive research on plasma electrolysis as pretreatment method for water hyacinth (WH) was performed based on lignin content, crystalline structure, surface property, and enzymatic hydrolysis. A large number of active particles, such as HO and H 2 O 2 , generated by plasma electrolysis could decompose the lignin of the biomass samples and reduce the crystalline index. An efficient pretreatment process made use of WH pretreated at a load of 48 wt% (0.15–0.18 mm) in FeCl 3 solution for 30 min at 450 V. After the pretreatment, the sugar yield of WH was increased by 126.5% as compared with unpretreated samples.

The mild acid pretreatment and the combination of biological pretreatment by a white rot fungus Echinodontium taxodii or a brown rot fungus Antrodia sp. 5898 with mild acid pretreatment were evaluated under different pretreatment conditions for enzymatic hydrolysis and ethanol production from water hyacinth. The combined pretreatment with E. taxodii (10 days) and 0.25% H(2)SO(4) was proved to be more effective than the sole acid pretreatment. The reducing sugar yield from enzymatic hydrolysis of co-treated water hyacinth increased 1.13-2.11 fold than that of acid-treated water hyacinth at the same conditions. The following study on separate hydrolysis and fermentation with Saccharomyces cerevisiae indicated that the ethanol yield from co-treated water hyacinth achieved 0.192 g/g of dry matter, which increased 1.34-fold than that from acid-treated water hyacinth (0.146 g/g of dry matter). This suggested that the combination of biological and mild acid pretreatment is a promising method to improve enzymatic hydrolysis and ethanol production from water hyacinth with low lignin content.