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.

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.

Purchasing Patterns and Consumer Level Waste of Fruits and Vegetables in Urban and Peri-Urban Centers in the Philippines

Fruits and vegetables are inherently perishable hence they are considered as one of the most wasted categories of food. While several studies have been conducted to assess consumer level waste of fruits and vegetables, few have been conducted in developing countries like the Philippines. A survey, using a pre-tested questionnaire, and involving 500 respondents, was conducted in selected urban and peri-urban areas in the Philippines, to ascertain consumer level fruit and vegetable waste. The quantities of fruits and vegetables wasted by supermarket shoppers and those who purchased fruits in wet markets were comparably low at 3% - 4%. This low level of consumer fruit and vegetable waste was attributed to the small quantities (250 to 500 grams per purchase) purchased by consumers in both categories of markets. Consumer level fruit and vegetable waste, showed a positive correlation to household size. The level of fruit waste was positively related to household income, and negatively related to shopper’s age. Consumers who shopped in supermarkets, purchased larger quantities of fruit when compared to those who shopped in wet markets. Wet market shoppers on the other hand, purchased large quantities of vegetables. Decay, and quality loss manifested by shriveling, wilting, toughening, browning and softening were the main characteristics of fruits and vegetables discarded by consumers. The underlying causes of this waste, cited by respondents included “forgot to eat”, “poor quality”, “forgot to cook” and “overbuying”. Consumer efforts to minimize waste include buying enough for consumption, consuming or using immediately after purchase, planning their menus, improving storage and purchasing produce that is of good quality.

Potentiality of Bioconverted Leafy Vegetable Waste as Aquaculture Feed Supplement

Purple non-sulfur bacteria (PNSB) are well known for their ability in transforming organic substrates for their own source of nutrients. The nutritional values of leafy vegetable waste could be improved through bioconversion with PNSB. This study was conducted to access nutritional status of leafy vegetable waste bio-converted product and efficacy of derived product as aquaculture feed supplement. Proximate compositions of bio-converted leafy vegetable wastes were improved after 6 days with 30% inoculums of Afifella marina strain ME (KC205142). The crude proteins (%) and ashes (%) in derived product was increased to 51.7% and 19.6% respectively. On the other hand, the fiber (%) in the bio-converted derived product was decreased by 21%. During feeding trial in Tilapia (Oreochromis niloticus), no significant differences were observed in the feed intake (g/fish/day), but significant differences were observed in the value of feed conversion ratio and weight gain (%) among the used diets. However, lower ingestion rate (g/d/fish) and better feed conversion ratio were obtained while fishes were fed with diet composed of commercial feed mixed with 5% of the bio-converted product. The higher ingestion rate (g/d/fish) and lower feed conversion ratio were observed with only commercial diet. There observed no significant differences in the ingestion rate (g/d/fish) and FCR values among the diet composed of commercial feed with 5% (D5) and 10% (D10) of the bio-converted product. The derived bio-converted product can be a promising approach to open new market segment in aquafeed industry.

Utilization of Vegetable Waste Juice by Purple Non-Sulfur Bacterium (Afifella marina Strain ME) for Biomass Production

This experiment was conducted to determine the possibility of utilization of vegetable waste juice in the production of purple non-sulfur bacterium Afifella marina biomass. Bacterium was cultured in four diluted such as, 10%, 20%, 30% and 40% (v/v) vegetable waste juices. In addition synthetic 112 media were used as control to compare the growth characteristics of Afifella marine. The bacterium Afifella marina grew well in 10% diluted vegetable waste juice in anaerobic light condition with the highest production of 5.02 g/l dry cell weight in fifth day of culture, whereas the highest total carotenoid production of 0.87 mg/g dry cell weight was recorded in third day of culture. The highest dry cell weight productions recorded in 10% of VWJ was significantly higher compared to four other treatments (F = 14.63;p = 0.00). However, the total carotenoid production of bacteria in 10% VWJ showed no significant difference compared to the carotenoid production in 112 synthetic media, but was significantly higher compared to three other treatments (P = 0.00). The bacterium, Afifella marina has the ability to use vegetable waste juice at certain level for the production of bacterial biomass.

Material-Efficient Utilization of Waste Oils—Biodegradability and Other Chemical Properties of Vegetable Recycling Oils

Material efficiency is nowadays an essential topic to promote the sustainable use of natural resources, waste materials and industrial by-products, in agreement with the principle of sustainable development and LCA (life cycle assessment). In this research it was determined the biodegradation of used vegetable oil based products and their important physico- chemical properties for their suitability in different applications such as chain oil in the forestry equipment and mold oil in concrete casting etc. Biodegradability is a measure of the ecological nature of products, and thus from an environ- mental point of view, is the most important evaluated property in this research. As a result, all measured properties of the studied recycled vegetable oils show that the products are environmentally friendly. Two types of vegetable oil were studied;three chain oils and two mold oils. The degree of biodegradation (BOD28) of the mold oils, was about 77 % and the biodegradation of chain oils was about 60% - 62%. In addition, this paper also presents a process outline for manu- facturing recycling vegetable oils.

Optimization of Biodiesel Production from Waste Vegetable Oil Assisted by Co-Solvent and Microwave Using a Two-Step Process

The two-step catalyzing process for biodiesel production from waste vegetable oil was assisted by both co-solvent and microwave irradiation. Central composite design (CCD) was employed to optimize the reaction conditions. Optimal reaction conditions of the first step were alcohol to oil molar ratio of 9:1, catalyst (H2SO4) amount 1 wt%, reaction temperature 333 K, and reaction time 7.5 minutes;while for the second step, optimal reaction conditions were alcohol to oil molar ratio 12:1, catalyst (NaOH) amount 1 wt%, reaction temperature 333 K, and reaction time 2.0 minutes. The total reaction time was 9.5 min and the conversion rate of fatty acid methyl esters (FAMEs) achieved was 97.4%. The total reaction time was shorter than previous studies. Therefore, the co-solvent and microwave assisted two-step catalyzing process has a potential application in producing biodiesel from waste vegetable oil.

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.

Demonstrative Study of Vehicles Using Waste Vegetable Oil as Fuel

SVO （straight vegetable oil） method means the direct use of vegetable oil as car fuel through installation of a heater unit in the car to decrease vegetable oil viscosity. In this study, the authors carried out performance tests on the direct use of waste cooking oil using a car with a heater unit, Moreover, the authors carried out long run driving on road tests in five years using a public car of Minami-Aizu Town in Fukushima Prefecture and analyzed the case of troubles and clarified the availability and problems of SVO vehicles. As a result, the car with a heater unit shows similar performance in both cases using vegetable oil or diesel fuel as fuel. The tested SVO vehicle of Minami-Aizu Town could be driven 38,127 km mainly by waste vegetable oil with a total driving distance of 52,293 km in long run driving tests in five years, and decreased about 3,813.5 liters of light oil which corresponds to 9.99 t of CO2.

Distribution pattern and limiting factors of vegetation in coal waste pile of Xinzhuangzi coal mine in Huainan

In China, coal mine spoils have traditionally been dumped in cone-shaped heaps that have the potential to pollute air, soil and water environments. The coal waste pile occupies lots of arable land and endangers the ecological system in the coal mine district. Vegetation restoration is an efficient approach for controlling the environment pollution of coal waste pile, and is also a topic of current interest in restoration ecology and degradation system ecology. This study focused on the distribu- tion pattern and limiting factors of vegetation in coal waste pile of Xinzhuangzi Coal Mine in Huainan. The results show that two stable plant communities （Synodon dactylon＋Erigeron bonariensis.L＋Setaria viridis community and Humulus scan- den＋Erigeron bonariensis. L community） exist at the bottom of the pile. Synodon dactylon and Erigeron bonariensis. L have much higher values of summed dominance ratio, which denote that these two species can be used for restoration of coal waste piles. The high levels of pH （8.77） and salinity, low levels of total P and total K in coal mine spoil can be the limiting factors for the residence and growth of vegetation.

The method on recovery of forest vegetation in degraded ecosystem in tropical and subtropical waste lowland in Guangdong

The aim of this paper is to discuss the reasonable method to set up the man-made ecosystem where the high productivity, high economic effects and ecological efficiencies, continual resources and suitable environment could be obtained.

Application of Lignin in Papermaking Waste Liquor in Slope-site Vegetation Construction

Exploration and practice were made to the mechanism, methods, func- tions, characteristics and application effects of the chemical modification of lignin in papermaking waste liquor used as base planting material additive to the vegetation construction in difficult slope-site. The results showed that after chemical modifica- tion, the base planting material additive had a lot of functions and good perfor- mance, which could effectively improve the water retention, fertilizer maintenance and nutrient-supply capacity of the plant matrix, as well as the stress resistances of plants, and it was especially suitable for the vegetation construction in the high and steep rock slopes where hydrothermal conditions were especially harsh and the construction and maintenance were very inconvenient to carry out. It provided new ideas and supporting technical to solving industry common problems, such as easy sliding of base planting material, easy degradation of vegetation, and provided a new approach for resource utilization of papermakina wastewater.

Research progress of vegetable oil and derivative in microbial fermentation for high-value-added metabolite production

Vegetable oil and derivative,as well as waste cooking oil,are important resources for microbial fermentation to produce high-value-added metabolites.Diversity of their compositions not only provides more choices for the fermentation by different microorganisms,but also is a challenge for their systematic utilization.According to the previous literature,4 main functions of vegetable oil and derivative can be summarized,such as carbon source,precursor,inducer and cell protectant during fermentation process.Currently,there is still insufficient knowledge about application of vegetable oil and derivative for high-value-added metabolite production.Therefore,this article firstly presented a comprehensive summary of compositions of vegetable oils and their derivatives,variety of corresponding microbial metabolites,limiting factors and optimization of fermentation process.

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).

京津冀地区蔬菜废弃物污染风险及资源化利用潜力分析

以京津冀地区13个地级市为研究对象,通过文献整理和数据分析,估算出各地级市蔬菜废弃物的污染负荷、污染强度和污染风险,并结合各地化肥施用量,探究蔬菜废弃物的资源化利用潜力。结果表明,2020年京津冀地区的蔬菜废弃物、TN、TP和TK污染负荷分别为2 199 836、46 627、28 509和49 674 t。各地级市中,唐山市、张家口市、石家庄市和邯郸市的污染负荷较高;廊坊市、唐山市、秦皇岛市和石家庄市的污染风险较高。若将京津冀地区蔬菜废弃物资源化利用,所利用带来的肥料化效益达到124 802 t,相当于区域内4.06%的化肥施用折纯量,资源化效益显著。因此,推动京津冀地区蔬菜废弃物的资源化利用对于缓解资源紧缺和环境污染具有重要意义。

尾菜发酵液对生菜生长的影响机理

目的将尾菜发酵制成液体肥料及土壤调理剂,解决大量设施尾菜处理难题,促进废弃物合理利用。方法将番茄藤蔓打碎后添加酶、红糖,经厌氧发酵制成发酵液,测定主要成分;以乳酸,硫酸铵、磷酸二氢钾和硫酸钾代替发酵液中有机酸和养分,进行生菜盆栽试验。结果施用发酵液、乳酸与肥料均会使土壤速效养分含量上升,与对照组相比,100%发酵液能使土壤中速效磷增加29.8%,67%发酵液处理使速效钾提高20.9%;发酵液的施用不仅提高了生菜产量,而且改善了生菜品质,施用后使生菜叶片中可溶性糖含量增加,并降低了叶片中的硝酸盐含量。结论尾菜发酵液对生菜生长的效果以乳酸对土壤速效磷、速效钾养分的活化作用为主,从而提高土壤养分含量并增加作物产量,同时发酵液能够改善生菜农艺性状。

北京市菜田废弃物处置产业现状、对策与展望

菜田废弃物的有效处置可有效解决环境污染问题,促进蔬菜产业提质增效、农业农村绿色发展。为了掌握北京市菜田废弃物处置现状,对北京市规模园区、合作社、生产类企业等存在的废弃物处置方面的问题进行了初步研究。基于对不同作物单位面积产废量、产废系数及产废时间的调查,从不同作物、不同区域等角度分别估算了菜田废弃物产生量,梳理了菜田废弃物处置的主要技术措施,总结了北京市各区菜田废弃物处置模式;围绕政策、资金、技术装备、宣传、监管等层面剖析了菜田废弃物处置存在的问题,从加大资金支持力度、加快配套技术装备研发、健全相关法律法规等方面研提了相应的对策及建议,并指出了菜田废弃物处置产业中肥料化处理、区域化集中处理和社会化服务方式的发展方向。

不同生物油再生沥青性能比选

为确定生物油对老化沥青性能的恢复能力,比选出再生能力较强的一种生物油并确定其最佳掺量,采用植物沥青、餐厨废弃油脂和工业用动物油3种生物油作为再生剂,分别对老化SBS改性沥青进行再生,通过测定生物油再生沥青的针入度、延度、软化点和布氏黏度并进行薄膜加热试验,研究生物油种类和掺量对老化沥青各项性能的影响规律。结果表明,3种生物油对老化SBS改性沥青的基础性能和耐老化性均有一定的恢复能力,其中餐厨废弃油脂对老化沥青再生能力较强,并且社会和经济效益较高,植物沥青和工业用动物油次之;餐厨废弃油脂被选为最佳再生生物油,掺量为4%时能够使老化SBS改性沥青的黏滞性和高温性能得到完全恢复,因此被确定为最佳掺量。

尾菜集约化处理系统的运行状况及优化分析

为探究大量未经科学化处理的尾菜污染环境及资源浪费问题的有效解决方法,以甘肃省兰州市某尾菜处理和循环利用系统工程为案例,对现行尾菜集约化处理模式下系统的运行现状进行分析。结果表明:该系统在2022年运行期间共处理尾菜48351.72 t,折合尾菜产气能力为10.85 m^(3)/t,达标废水排放量共计48646 m^(3),产沼渣共计3901.5 t,处理成本达到86.78元/t;系统在运行过程中对尾菜的可回收资源利用不充分,未实现完全无害化,整体存在效率低、能耗高和运行成本高等问题。针对现行系统存在的问题分析其原因并提出系统运行的优化方案,为尾菜集约化处理模式的工艺优化提供一定依据,对尾菜资源化利用的持续健康发展有重要意义。

蔬菜废弃物水热产物对土壤理化性状的影响

蔬菜废弃物营养丰富、产量大,但直接利用效率不高。水热处理技术可实现其减量化资源化循环利用,大大降低其环境应用风险。以经过180、210、240℃不同温度处理的蔬菜废弃物水热产物作为有机改良肥,对土壤进行为期35d的盆栽试验,结果表明:随着培养时间的延长,土壤pH值变化微小,而EC值不断增大,可达0.833 mS/cm;有机质含量先升后降,最大值为10.30 g/kg;氮磷钾养分含量逐渐升高,总养分最高达3.43%;土壤微生物以变形杆菌门和厚壁菌门等有益菌为主。蔬菜废弃物经过高温水热处理后生成的固态产物可作农肥使用,对碱性土壤具有较好的改良特性,最适宜处理温度为210℃。