Optimizing Household Wastes (Rice, Vegetables, and Fruit) as an Environmentally Friendly Electricity Generator

The high consumption of electricity and issues related to fossil energy have triggered an increase in energy prices and the scarcity of fossil resources.Consequently,many researchers are seeking alternative energy sources.One potential technology,the Microbial Fuel Cell(MFC)based on rice,vegetable,and fruit wastes,can convert chemical energy into electrical energy.This study aims to determine the potency of rice,vegetable,and fruit waste assisted by Cu/Mg electrodes as a generator of electricity.The method used was a laboratory experiment,including the following steps:electrode preparation,waste sample preparation,incubation of the waste samples,construction of a reactor using rice,vegetable,and fruit waste as a source of electricity,and testing.The tests included measuring electrical conductivity,electric current,voltage,current density,and power density.Based on the test results,the maximum current and voltage values for the fruit waste samples were 5.53 V and 11.5 mA,respectively,with a current density of 2.300 mA/cm^(2) and a power density of 12.719 mW/cm^(2).The results indicate the potential for a future development.The next step in development involves determining the optimum conditions for utilizing of rice,vegetable,and fruit waste.The results of the electrical conductivity test on rice,vegetable,and fruit waste samples were 1.51,2.88,and 3.98 mS,respectively,with the highest electrical conductivity value found in the fruit waste sample.

Feeding of processed vegetable wastes to bulls and its potential environmental benefit

The study was conducted with the objectives to quantify year round availability of different vegetables waste(VW) in a wholesale market and to determine the inclusion level of a processed VW(VWP) in the diets of bulls. The daily VW biomass availability at Kawran bazaar, Dhaka, Bangladesh was quantified by weighing the vegetable supply and their wastes by visiting 2 days in a week. Concurrently, VW of cucumber, bitter gourd, spotted gourd, brinjal, pumpkin, potato, tomato, ladies finger, and snake gourd representing 0.21, 0.18, 0.17, 0.16, 0.09, 0.07, 0.06, 0.03, and 0.02 as fresh fractions, respectively were blended, dried and stored while adding rice polish and common salt at 200 and 20 g/kg DM, respectively;it was tested in bulls as an ingredient of concentrate mixture. Four dietary groups, each of 6 bulls, with initial average live weight(LW) of 85.47 ± 17 kg, were fed fresh German grass(Echinochloa polystachya)ad libitum supplemented with 4 different concentrates containing 0, 10%, 20% and 30% VWP at the rate of1% of LW for 89 days. The availability of VW biomass of the market was 42.51 t/d and recycling of them as feed, instead of using landfills, might reduce annual methane emission by 0.43 Gg. The inclusion of VWP in the diet up to 9.7% of DM, or 0.30% of LW of bulls showed no significant effect on the DM intake,digestibility, growth performance and health status of bulls. The dietary DM intake represented 3.10%,3.09%, 3.20% and 3.14% of LW resulting in daily gain of 302, 300, 312 and 344 g, respectively. The digestibility of DM of diets was 56.9%, 62.8%, 62.8% and 63.4%, respectively. It was concluded that VWP may be included at a level of 9.7% of the diet(DM basis) or 0.30% of LW of bulls.

Microbial community structures in an integrated two-phase anaerobic bioreactor fed by fruit vegetable wastes and wheat straw

The microbial community structures in an integrated two-phase anaerobic reactor（ITPAR）were investigated by 16 S r DNA clone library technology. The 75 L reactor was designed with a 25 L rotating acidogenic unit at the top and a 50 L conventional upflow methanogenic unit at the bottom, with a recirculation connected to the two units. The reactor had been operated for 21 stages to co-digest fruit/vegetable wastes and wheat straw, which showed a very good biogas production and decomposition of cellulosic materials. The results showed that many kinds of cellulose and glycan decomposition bacteria related with Bacteroidales,Clostridiales and Syntrophobacterales were dominated in the reactor, with more bacteria community diversities in the acidogenic unit. The methanogens were mostly related with Methanosaeta, Methanosarcina, Methanoculleus, Methanospirillum and Methanobacterium; the predominating genus Methanosaeta, accounting for 40.5%, 54.2%, 73.6% and 78.7% in four samples from top to bottom, indicated a major methanogenesis pathway by acetoclastic methanogenesis in the methanogenic unit. The beta diversity indexes illustrated a more similar distribution of bacterial communities than that of methanogens between acidogenic unit and methanogenic unit. The differentiation of methanogenic community composition in two phases, as well as pH values and volatile fatty acid（VFA） concentrations confirmed the phase separation of the ITPAR. Overall, the results of this study demonstrated that the special designing of ITPAR maintained a sufficient number of methanogens, more diverse communities and stronger syntrophic associations among microorganisms, which made two phase anaerobic digestion of cellulosic materials more efficient.

Prediction of methane production performances based on determination of organic components for different vegetable wastes

The rapid development of the economy has led to rapid consumption of fossil fuels,which results in extremely serious environmental problems.Biomass energy has been accepted as a way to reduce the usage of fossil fuels due to its cleanliness and renewability.In this study,vegetable wastes(VWs),an abundant kind of biomass resource,were treated by anaerobic digestion(AD)to be converted into methane.The total solids(TS),volatile solids(VS),elemental contents,and organic components of 17 kinds of typical VWs were systematically determined.The methane production performances were then measured and ranged from 120.1 mL/g VS(for pepper stem)to 377.7 mL/g VS(for bok choy).To easily and quickly predict the methane yields of VWs,a curvilinear relationship between different organic compositions(e.g.,cellulose,hemicellulose,lignin,non-structural carbohydrate,protein,and VFA contents)and methane production was established and proved to be a useful tool for methane prediction.Four kinetic models(first-order model,Fitzhugh model,Cone model,modified Gompertz model)were applied to simulate the process of AD,and Cone and modified Gompertz models were shown to describe the AD process well.This study will not only provide basic data about the characteristics and methane production of 17 kinds of VWs but also contribute a method for predicting the methane yields of vegetable wastes,which is also valuable in future agro-industrial applications.

Effects of Superphosphate Addition on NH_3 and Greenhouse Gas Emissions During Vegetable Waste Composting

To study the effects of superphosphate（SP） on the NH_3 and greenhouse gas emissions,vegetable waste composting was performed for 27 days using 6 different treatments. In addition to the controls,five vegetable waste mixtures（0.77m^3 each） were treated with different amounts of the SP additive, namely, 5%, 10%,15%, 20% and 25%. The ammonia volatilization loss and greenhouse gas emissions were measured during composting.Results indicated that the SP additive significantly decreased the ammonia volatilization and greenhouse gas emissions during vegetable waste composting. The additive reduced the total NH_3 emission by 4.0% to 16.7%. The total greenhouse gas emissions（CO_2-eq） of all treatments with SP additives were decreased by 10.2% to 20.8%, as compared with the controls. The NH_3 emission during vegetable waste composting had the highest contribution to the greenhouse effect caused by the four different gases.The amount of NH_3（CO_2-eq）from each treatment ranged from 59.90 to 81.58 kg/t; NH_3（CO_2-eq） accounted for 69% to 77% of the total emissions from the four gases. Therefore, SP is a cost-effective phosphorus-based fertilizer that can be used as an additive during vegetable waste composting to reduce the NH_3 and greenhouse gas emissions as well as to improve the value of compost as a fertilizer.

Use of Waste Vegetable Biomasses Treated by Steam Explosion for the Horticultural Crop Protection

The purpose of this study was to assess the suppressive effect of Waste Vegetable Biomasses （WVBs） treated by the Steam Explosion technique in a continuous plant, against soil-borne plant pathogens. In order to assess their disease suppression, five WVBs （Miscanthus biomass, durum wheat straw, rice straw, corn stalk and wood shaving） and commercial compost were tested in vivo at three different doses （10, 20 and 30% of potting mix） on seven horticultural pathosystems plant/fungus： tomato/Phytophthora nicotianae, cucumber/Pythium ultimum, lettuce/Fusariurn oxysporum f. sp. lactucae, melordFusariurn oxysporum f. sp. melonis, bearffRhizoctonia solani, eggplant/Verticillium dahlie and fennel/Sclerotinia sclerotiorum. The results showed that the corn stalk was more efficient respect to Miscanthus, compost, wheat straw, rice straw and wood shaving in all the patbosystems and at all the doses tested. The corn stalk suppression ranged from 97% in eggplant/F, dahliae to 35% in lettuce/F, oxysporum f. sp. lactucae, and it was significantly higher with respect to the other substrates. In general, the wheat straw, rice straw and wood shaving were statistically found less efficient as suppressive substrate with respect to corn stalk, Miscanthus and compost at the 30% dose in four pathosystems In particular, the wood shaving suppressiveness ranged from 48% in eggplant/V, dahliae to 12% in lettuce/F, oxysporum f. sp. lactucae. The different suppressiveness observed could be attributed to different concentration of the microbial inhibitory substances （furfurals, organic acids and lignosulfonates） produced during the processing of fresh biomass.

Rheological Characterization of a Mixed Fruit/Vegetable Puree Feedstock for Hydrogen Production by Dark Fermentation

Bio-hydrogen (Bio-H2) production from the organic fraction of solid waste, as fruit and vegetable wastes, constitutes an interesting and feasible technology to obtain clean energy. In spite of the feasibility to produce Bio-H2 from fruit/vegetable wastes (FVW), data about its rheological characterization are scarce. This information is useful to establish the hydrodynamic behavior, which controls the overall mixing process when the feedstock for Bio-H2 production process is a mixture of FVW. In this work, the rheological behavior of a vegetable/fruit waste mixture was characterized. The effect of the solids content (%, w/w), temperature, time (tyxotropy effects) and shear rate over the apparent viscosity of the mixture was evaluated. Most of the mixtures showed non-Newtonian behavior. The curves are typical rheofluidizing fluids. The rheological curves were different at increasing solids contents (80%, 60%, 40% and 30%), independent from the temperature. Rheological data were fitted to the power law model. Correlation factors R2 for the different mixtures were 0.991-0.995 for 80%, 0.961 -0.986 for 60%, 0.890 -0.925 for 40%. In the case of 30% of solids, the R2 value was not acceptable, and it was also found that this mixture was very near to the Newtonian behavior. Calculated activation energies (Ea) values were 15.98, 14.89 and 20.96 kJ/mol for the 80%, 60%, 40% mixtures, respectively. FVW purees rheological behavior was well characterized by Carbopol solutions at given concentrations and pH values. This fluid can be used as a model for other studies, e.g. LDA (Laser Doppler Anemometry) and PIV (Particle Image Velocimetry).

Kaempferol and its derivatives:Biological activities and therapeutic potential

Kaempferol,a natural plant-origin flavonoid,exhibits therapeutic anti-inflammatory,antioxidant,anticancer,antidiabetic,and neuroprotective properties.Kaempferol acts within several distinct mechanisms like apoptotic induction in cancer cells,enzymatic inhibition,signalling pathway inhibition,and downregulation in cell viability during the G2/M phase of cell division.This review summarizes the therapeutic effects of kaempferol against several health ailments.The recent progress on kaempferol obtained from fruits and vegetables as an antioxidant,anti-inflammatory,anticancer,antidiabetic,and neuroprotective agent and its mechanisms of action are also discussed.In addition,kaempferol has been reported to be present in wastes and byproducts from post-fruit and vegetable processing.Thus,a paradigm shift towards valorizing fruits and vegetable industrial wastes/byproducts to obtain bioactive kaempferol can support the circular economy pillar for generating wealth from waste and for finding a sustainable alternative source.

Numerical simulation of vegetated mine dump slope with reference to small plants

The present paper discusses the effects of small plants on the dump mass reinforcement and slope stability.The roots of smaller plants(such as grasses and shrubs)do not go deep.However,they stabilize the slope by binding the upper layer of dump slope.Shear strength of the dump mass with and without root reinforcement is determined by laboratory shear box instrument.The increased cohesion(apparent cohesion)of upper layer of the dump mass due to plants is determined by fabricated shear box.The kinetic behavior of the dump has been investigated using the FLAC software.The factor of safety has been calculated in order to determine the possible effect of small plants on the stability of the dump slope.It is observed that the small plants do not significantly improve the factor of safety(FOS)of slope.However,it could be useful for early stabilization.The grasses quickly bind the upper surface,whereas shrubs too immensely strengthen the stability of the dump in the initial stage.

Determination and evaluation of biogas and methane productions of vegetable and fruit wastes with Hohenheim Batch Test method

Nowadays,biogas technology applications are gradually increasing worldwide due to the economic and environmental benefits.Many researches and studies related to the determination of the biogas potential of organic waste materials have been carried out in the recent years.Studies to determine the specific methane potential of organic waste materials have a great importance for both design and economical operation of the biogas plants.Energy potential that will be recovered from organic wastes is substantial in Turkey.Thanks to biogas plants gathering vegetable-fruit wastes and other organic wastes are planned to produce significant amount of renewable energy in Turkish markets.Owing to the use of organic wastes,the disposal of waste as well as energy production,soil,water and air pollution in terms of environmental protection are also minimized.On the other hand,the organic wastes produced from plants can also be utilized as fertilizer in vegetable production.In this study,the cumulative biogas and methane production of vegetable and fruit wastes were experimentally determined with HBT(Hohenheim Batch Test)method.Biogas and methane yields of vegetable and fruit wastes were found as 0.54-0.73 Nm^(3)/(kg ODM)and 0.29-0.37 Nm^(3)/(kg ODM),respectively.The highest value of the cumulative specific methane production was tomato wastes(0.37 Nm^(3)/(kg ODM)),and the lowest value was lettuce wastes(0.29 Nm^(3)/(kg ODM)),as well.The average cumulative specific methane production values of mixed vegetable and fruit wastes are determined as 0.34 Nm^(3)/(kg ODM).

Hydro Bioreactor a Sustainable Technology for Vermicomposting

The adverse impact of chemical agriculture in the India on the soil, water, environment and human health （of consumers and farm families） exacerbates rural poverty, even as agriculture productivity remains low. Poor families, especially women, are the most affected by the health and environmental risks that are brought on by chemical agriculture, and they are hardest hit by the deteriorating productivity. On the other hand, the solid waste management problem in India is increasingly being felt in rural and urban areas. In this study, the author proposes to practice ofvermicomposting as technology for both sustainable agriculture and solid waste management, using the Hydro Bioreactor with vegetable waste. This technique is studied in the present research work which is simple and potentially inexpensive. Experiments were conducted to determine the changes in the physicochemical parameters and the dominant species of microorganisms at different temperatures during entire process of vermicomposting were investigated. The vermicompost developed in the hydro bioreactor was found to have comparatively high value of nutrients which can serve as natural fertilizer. The hydro bioreactor vermicomposting has proved very effective and efficient for developing compost from vegetable waste.

Survey on solidwastesmanagement by composting: Optimization of key process parameters for biofertilizer synthesis from agro wastes using response surface methodology (RSM)

The optimization of key process parameters for the transformation of agrowastes into biofertilizer has been demonstrated using response surface methodology(RSM).Biofertilizerwas produced by composting using 120 L capacity drum made of polyethylene as the composter.Composting time(X1),dosage ratio(X2)and moisture content(X3)were the independent factors while percentage nitrogen,phosphorus and potassium(N.P.K)were the response factors.The outcomes exhibited that composting time,dosage ratio and moisture content all significantly affects the mineralization of N.P.K at probability value of 0.0001.The coefficients of determination also called regression coefficients of 98.60%,99.79%and 97.80%for nitrogen,phosphorus and potassiumobserved between the predicted and the real value are obvious that the developed regression models can fit the experimental data well.It was seen from the optimization studies that the pinnacle value of N.P.K from the ideal conditions are 9.62%,8.97%and 5.62.Characterization of the composite uncovered that biofertilizer produced has a high potential for commercial application on agricultural land.It can be concluded that combination of sawdust,sewage sludge and vegetable waste is a good mixture for biofertilizer synthesis.Also,the nutrients release by the compost materials during the process of composting may be maximized when process conditions are circumspectly managed within the reported optimal value.

Effects of mixture ratio on anaerobic co-digestion with fruit and vegetable waste and food waste of China

The biochemical methane potentials for typical fruit and vegetable waste （FVW） and food waste （FW） from a northern China city were investigated, which were 0.30, 0.56 m3 CH4/kgVS （volatile solids） with biodegradabilities of 59.3% and 83.6%, respectively. Individual anaerobic digestion testes of FVW and FW were conducted at the organic loading rate （OLR） of 3 kg VS/（m3-day） using a lab-scale continuous stirred-tank reactor at 35°C. FVW could be digested stably with the biogas production rate of 2.17 ma/（m3-day） and methane production yield of 0.42 m3 CH4/kg VS. However, anaerobic digestion process for FW was failed due to acids accumulation. The effects of FVW： FW ratio on co-digestion stability and performance were further investigated at the same OLR. At FVW and FW mixing ratios of 2：1 and 1：1, the performance and operation of the digester were maintained stable, with no accumulation of volatile fatty acids （VFA） and ammonia. Changing the feed to a higher FW content in a ratio of FVW to FW 1：2, resulted in an increase in VFAs concentration to 1100-1200 rag/L, and the methanogenesis was slightly inhibited. At the optimum mixture ratio 1：1 for co-digestion of FVW with FW, the methane production yield was 0.49 m3 CH4/kg VS, and the volatile solids and soluble chemical oxygen demand （sCOD） removal efficiencies were 74.9% and 96.1%, respectively.

Anaerobic digestion in mesophilic and room temperature conditions: Digestion performance and soil-borne pathogen survival

Tomato plant waste（TPW） was used as the feedstock of a batch anaerobic reactor to evaluate the effect of anaerobic digestion on Ralstonia solanacearum and Phytophthora capsici survival. Batch experiments were carried out for TS（total solid） concentrations of 2%, 4% and 6% respectively, at mesophilic（37 ± 1°C） and room（20–25°C） temperatures. Results showed that higher digestion performance was achieved under mesophilic digestion temperature and lower TS concentration conditions. The biogas production ranged from 71 to 416 L/kg VS（volatile solids）. The inactivation of anaerobic digestion tended to increase as digestion performance improved. The maximum log copies reduction of R. solanacearum and P. capsici detected by quantitative PCR（polymerase chain reaction） were 3.80 and 4.08 respectively in reactors with 4% TS concentration at mesophilic temperatures. However, both in mesophilic and room temperature conditions, the lowest reduction of R. solanacearum was found in the reactors with 6% TS concentration, which possessed the highest VFA（volatile fatty acid） concentration. These findings indicated that simple accumulation of VFAs failed to restrain R. solanacearum effectively, although the VFAs were considered poisonous. P. capsici was nearly completely dead under all conditions. Based on the digestion performance and the pathogen survival rate, a model was established to evaluate the digestate biosafety.