Sustainable Management of Biodegradable Waste in Guinea: Effect of Compost on Eggplant and Chilli Crop Yields Pepper

The fight against insalubrity in large urban and peri-urban agglomerations is a major challenge in developing countries. This problem is compounded by that of sustainable waste management mechanisms. Indeed, the current waste collection system in Guinea has proved inadequate, as moving garbage from point “A” to point “B” is tantamount to “moving the problem”. The aim of this experimental work is to demonstrate the cost-effectiveness and benefits of sustainable waste management. As part of this drive to valorize biodegradable waste, the Waste Management Research Center has undertaken a series of activities ranging from composting organic waste to testing compost on certain crop varieties. An experimental field of 8024 m2 was laid out and treated with 1500 Kg of fine compost in doses ranging from 2.5 to 5 T/ha. Two crop varieties, eggplant and chili, were tested. Compost application increased production yields: 15 to 21 tonnes of eggplant and 10.4 to 11.1 tonnes of chili per hectare. Growth rates compared with usual yields varied from 50% to 64% and from 11% to 17% for eggplant and chili, respectively. This study resulted in an optimum compost dose of 2.5 T/ha for this phase.

Comparative Analysis of Lactuca sativa Growth Using Compost Versus Conventional Soil

Conventional agricultural techniques have been degrading American soils nationwide since the beginnings of modern-day agriculture through practices such as soil tilling, using nitrogen synthetic fertilizers, and monocultural systems. These techniques contribute to degrading soil health, mass emissions of carbon dioxide into the atmosphere, and decreased biodiversity. Regenerative agriculture techniques include the utilization of cover crops, compost, no-tillage, the integration of livestock, and crop rotation. The APS Laboratory for Sustainable Agriculture focused on the effectiveness of compost by comparing the growth of lettuce in four different treatments: 100% Compost (100%C), 75% Compost 25% Miracle-Gro (75%C - 25%MG), 50% Compost 50% Miracle-Gro (50%C - 50%MG), and finally, 100% Miracle-Gro (100%MG). The lettuce seeds were kept in a growth tent for fifteen days during their period of germination before being transferred to four 1 × 1 × 0.15 m plots in the Food Forest at Florida Gulf Coast University (FGCU) for the 60-day growth period. The lettuce crops grew to full bloom and were ready for harvest. Sampling events took place every six days in which crop growth data including wet weight (g), dry weight (g), nitrogen (mg/g), chlorophyll concentration (mg/cm2), and leaf area (LA) (cm2) were collected. Statistical analysis was then conducted from the data. Based on the statistical tests conducted at the 5% significance level using R statistical software, soil treatment type was found to be significant (p = 0.0002). Soil treatment type was shown to have significantly impacted wet weight (p χ2 [3] = 3.91, p = 0.2717). 100%C and 100%MG of soil treatments produced the most successful lettuce crops. The 100%C soil treatment yielded lettuce crops with the heaviest wet weights and the largest LAs, and the 100% MG soil treatment yielded the heaviest dry weights and the highest nitrogen readings. Results demonstrate the effectiveness and feasibility of using compost as a technique for regenerative agriculture.

Comparative Effects of Compost and Arbuscular Mycorrhizal Fungi Versus NPK on Agro-Physiological,Biochemical and Tolerance Responses of Tomatoes to Drought

Drought stress(DS)and overuse of chemical fertilizers cause considerable losses in the agro-physiological as well as biochemical performance of plants.In this context,considerable effort will be required to replace chemical fertilizers(NPK)with biostimulants as an important approach to enhance the productivity and sustainability of agriculture.Here,we evaluated the effect of separating and/or combining arbuscular mycorrhizal fungi(AMF)with compost(C)in comparison to the use of NPK on the growth,physiological and biochemical of tomatoes under DS.The findings showed that DS significantly reduced the growth and physiological attributes of tomatoes.Furthermore,the treatment of AMF and C showed better results in agro-physiological and fruit quality compared to the NPK and control under DS.The combination of AMF and C(C+AMF)increased leaf water potential by 18.8%,stomatal conductance by 14.1%,fresh fruit weight by 25.0%,shoot dry matter by 104%and root dry matter by 56.1%compared to the control under DS.The study revealed that C+AMF caused a significant increase in sugar,protein and activity of polyphenoloxidase and peroxidase in leaves and fruits,and an opposite trend was observed in the case of malonaldehyde and hydrogen peroxide compared to NPK and control under DS.In conclusion,it is recommended to utilize the combination of AMF with compost to enhance the growth,yield,osmotic adjustment,and antioxidant capacity of tomato plants.This approach can boost their resilience to water stress and improve overall fruit quality.

Effect of Chicken Manure, Compost and Cow Dung on the Growth and Yield of Sweet Potato [Ipomoea batatas (L.) Lam.] under Guinea Savannah Agroecological Zone of Ghana

Twelve percent (12%) of Ghanaians are food insecure, and climate-smart crops like sweet potatoes are required to help end poverty. Small-scale farmers in Ghana who produce low-technology, subsistence crops, such as sweet potatoes, are more food secure than those who do not. This study was initiated to investigate the effect of chicken manure, compost, and cow dung on the growth and yield of “apomuden”, “SARI-Nyoriberigu”, “SARI-Nan” and “kufour” sweet potato under the Guinea Savannah agroecological zone of Ghana. Organic fertilizer increased leaf chlorophyll content and leaf area index. The application of cow dung, chicken manure and compost in 2015 significantly increased total storage root yield by 38%, 55% and 98%, 62%, 45% and 37%, 52%, 61% and 44%, and 33%, 36% and 28% for SARI-Nyoriberigu, Kufour, SARI-Nan and Apomuden, respectively, when compared to the untreated check. In 2016, and in comparison with the untreated check, the application of cow dung, chicken manure and compost increased total storage root yield by 42%, 61% and 93%, 69%, 49% and 41%, 57%, 67% and 48%, and 36%, 39% and 30% for SARI-Nyoriberigu, Kufour, SARI-Nan and Apomuden, respectively. Hence, the application of organic fertilizers will increase sweet potato yield, give higher returns to resource-poor smallholder farmers and contribute to enhancing food and nutrition security.

Effect of Different Rates and Mixtures of Solid Household Waste and Faecal Sludge-Based Composts on Soil Fertility and Productivity of Sunflower (Helianthus annuus L.) in Dschang, West Cameroon

The unbalanced and inadequate use of fertilizers is one of the causes of soil degradation. Combined with the ever-increasing population, it is necessary to find sustainable agricultural production alternatives. The present work aims to determine the effect of different rates and mixtutes of organic amendments on soil fertility and the performance of Sunflower (Helianthus annuus L.). In the field, treatments consisted of solid household waste and faecal sludge in the ratios of 3/5 (V1), and a mixture of faecal sludge and household waste in the ratio of 3/5 with 900 worms (V2). At the end of the composting process, V1, V2 composts and the poultry manure (PM) were applied at rates of 4, 5 and 6 t∙ha−1 in a randomized complete block design with three replications. Soil samples were collected before and after the experiment and analyzed. The main results revealed that at the end of the composting process, there was a progressive improvement in the physico-chemical properties of V1 and V2 composts. In particular, the C/N ratio, phosphorus (P) and total nitrogen (TN) initially at 16.49 ± 0.42 (V1, V2), 21.06 ± 0.07 mg∙kg−1 (V1, V2), 0.76% ± 0.08% (V1, V2) respectively, increased after 60 days to 12.40 ± 0.41 (V1), 9.74 ± 0.28 (V2) for C/N, 21.94 ± 0.63 mg∙kg−1 (V1) and 22.04 ± 0.04 mg∙kg−1 (V2) for P, 0.96% ± 0.0% (V1) and 1.22 ± 0.04 (V2) for TN. The application of 6 t∙ha−1of PM had the greatest influence on the diameter and weight of the flower heads (27.16 ± 4.01 t∙ha−1 and 230.83 ± 2.64 t∙ha−1), while 4 t∙ha−1 of V2 gave the tallest sunflower plants (110.07 ± 73.28 cm) as well as the diameter at the crown (19.30 ± 9.07 cm). However, CEC was most influenced by 4 t∙ha−1 of V1, while 4 t∙ha−1 of PM had the greatest effect on organic carbon and phosphorus. However, 5 t∙ha−1 of PM showed the highest sunflower production and yield (1.67 ± 0.21 t∙ha−1). The combination with 900 earthworms is recommended for composting and 5 t∙ha−1 of PM is recommended to obtain a better sunflower production.

Assessment of the Characteristics of the Municipal Solid Waste Compost in Lebanon

Waste management is crucial due to the fast increase of human population, causing an increase in solid waste generation which if not properly managed causes environmental problems. Around 57% of the wastes generated from homes are made up of green material (fruits, vegetables…). Thus, reusing and recycling green wastes through composting is one way of reducing the waste load to landfills. Composting is the transformation of raw organic materials into organic soil amendments that provide nutrients to crops and enhance the tilth, fertility, and productivity of soils. Aerobic windrow composting system at Sukomi Greensite facility located at Karantina is performed, where materials biodegrade under controlled conditions to produce compost. However, assessment of the quality of the compost is fundamental in order to determine its usages. Thus, regular testing of physical, chemical and biological parameters was performed for adequate monitoring purposes. The basic objective of this study was to determine the characteristics of the Lebanese municipal solid waste compost on a yearly basis and compare these characteristics amongst the years. Hence, each parameter was tested and compared to the BNQ international Canadian standards for proper classification of the compost and adequate identification of its usages. The preliminary data obtained were statistically diagnosed through principal component analysis by Spadv55 software. All the data reflected the normal content value of the studied parameters with minor differences between the years except for year 2007 which demonstrated higher levels of Potassium, Phosphate, Lead and Cadmium. The characteristics of the compost enabled it to be used as a soil amendment on all types of agricultural and landscape commodities at the adequate dosages and proper timing. This data will additionally reflect the efficiency of the solid waste management practices adopted via highlighting the importance of the implementation of the integrated solid waste management practices.

Split Addition of Nitrogen-Rich Substrate at Thermophilic and Mesophilic Stages of Composting: Effect on Green House Gases Emission and Quality of Compost

Composting as a solution to the increasing generation of municipal solid waste (MSW), also contribute to GHGs emission when not controlled and could lack some basic nutrients, especially nitrogen. This study assessed the split-additions of nitrogen-rich substrate to composting materials and their effect on GHGs emissions as well as the quality of the composts. Nitrogen-rich substrates formulated from pig and goat manure were co-composted with MSW for a 12-weeks period by split adding at mesophilic (˚C) and thermophilic (>50˚C) stages in five different treatments. Representative samples from the compost were taken from each treatment for physicochemical, heavy metals and bacteriological analysis. In-situ CH4, CO2, N2O gas emissions were also analyzed weekly during composting. It was observed that all the treatments showed significant organic matter decomposition, reaching thermophilic temperatures in the first week of composting. The absence affects the suitable agronomic properties. All nitrogen-rich substrate applied at thermophilic stage (Treatment two) recorded the highest N, P and K concentrations of 1.34%, 0.97% and 2.45%, respectively with highest nitrogen retention. In terms of GHG emissions, CO2 was highest at the thermophilic stage when N-rich substrate was added in all treatment, while CH4 was highest in the mesophilic stage with N-rich substrate addition. N2O showed no specific trend in the treatments. Split addition of the N-rich substrate for co-composting of MSW produced compost which is stable, has less nutrient loss and low GHG emissions. Split addition of a nitrogen-rich substrate could be an option for increasing the fertilizer value of MSW compost.

Agronomic Performances of Manure Composts in Simplified Soilless Tomato Cultivation

Composts are recognised as an important source of nutrients for crops. The study aims to valorise agricultural by-products by composts made from broiler (A), laying hen (B) and bovine (C) manures in soilless tomato cultivation. Treatments consisted of these three composts and controls consisting of coconut fibres fed with a nutrient solution. The system is a randomised Fisher block with three replications. Each elementary plot consisted of nine tomato plants. Chemical parameters of the substrates and agronomic parameters of the plants were recorded from 14 to 49 days after transplanting (DAT). The pH stabilised at around 6.2 after varying from 7.1 to 8.0 in the composts. The high electrical conductivity (5.9 - 6.01 dS/m) was less than 1 dS/m at 49 DAT. Agromorphological parameters were close to the controls. Fruit necrosis was higher in the compost-based substrates (13.75% - 32.22%) than in the controls (<2%). Healthy fruit yields from the composts (38.7 - 48.7 t/ha) were high, although lower than those from the controls (49.9 - 57.4 t/ha). Fruit harvested from these substrates had a longer average shelf life (38.23 days) than the controls (28.5 days). This study showed that composts have fertilising properties for soilless tomato cultivation, in particular that of laying hen manure (48.33 t/ha). These composts could provide an alternative to the use of chemical fertilisers in soilless tomato cultivation.

Urban Soil Compaction Remediation by Shallow Tillage and Compost in Hydroseeded Lawn

Construction activities often involve removal of topsoil and compaction of the exposed soil by heavy equipments. Such compacted soils with low organic matter can lead to low infiltration and poor vegetation establishment. The objective of this study was to investigate the efficacy of tillage (shallow till) and compost on soil physical and biological properties in a hydroseeded lawn as a post-construction best management practice for soil compaction remediation. The experimental site received a total of four land treatments in five replicated trials and it was hydroseeded with common Bermuda grass: 1) No Tillage + Compost (NT-C), 2) No Tillage + No Compost (NT-NC;control), 3) Tillage + Compost (T-C), and 4) Tillage + No Compost (T-NC). Bulk density (BD), infiltration rate (IR), and wet aggregate stability (WAS) in each plot were measured to assess soil physical properties while soil organic matter (SOM) and enzyme activity (β-glucosidase, acid-phosphatase, and alkaline-phosphatase) were measured for soil biological properties. Over a 15-months of monitoring period, the shallow tillage loosened the soil initially, but its effect on BD without compost was diminished to control plot level (NT-NC) within 4 months after hydroseeding. Both tillage and compost led to an increase in IR, and it remained higher than control by 2 - 3 times throughout the observation period. The WAS and β-glucosidase activity decreased in tilled plot unless there was compost application. Turfgrass showed greener leaves and aggregated roots in the compost-amended plots (NT-C and T-C). Our results suggest that compost application plays a key role in improving soil physical and biological properties in hydroseeded lawns from construction sites.

Analysis of the Fertilizing and Bioremediation Potential of Leaf Litter Compost Amendment in Different Soils through Indexing Method

This research study explored the efficacy of leaf litter compost as a sustainable soil amendment with the objective of promoting soil health and mitigating the accumulation of potentially toxic elements. The investigation encompassed the impact of various organic compost amendments, including leaf compost, cow dung manure, kitchen waste compost, municipal organic waste compost, and vermicompost. The study employed Inductively Coupled Plasma Mass Spectrometry (ICP-MS) to evaluate soil nutrient levels and concentrations of Potentially Toxic Elements (PTEs) such as arsenic, chromium, cadmium, mercury, lead, nickel, and lithium. The fertilization and bioremediation potential of these compost amendments are quantified using an indexing method. Results indicated a substantial increase in overall nutrient levels (carbon, nitrogen, phosphorus, potassium, and sulfur) in soils treated with leaf compost and other organic composts. Fertility indices (FI) are notably higher in compost-amended soils (ranging from 2.667 to 3.938) compared to those amended with chemical fertilizers (ranging from 2.250 to 2.813) across all soil samples. Furthermore, the mean concentrations of PTEs were significantly lower in soils treated with leaf compost and other organic compost amendments compared to those treated with chemical fertilizers amendments. The assessment through the indexing method revealed a high clean index (CI) for leaf compost amendment (ranging from 3.407 to 3.58), whereas the chemical fertilizer amendment exhibits a relatively lower CI (ranging from 2.78 to 3.20). Consequently, leaf compost and other organic composts exhibit the potential to enhance sustainable productivity, promoting soil health and environmental safety by improving nutrient levels and remediating potentially toxic elements in the soil.

Sterilization Effects of Bacterial Inhibitor on Escherichia coli in Cattle Manure Compost

[Objective] The aim of this study was to explore the sterilization effects on Escherichia coli by adding bacterial inhibitor(CaCN2)during the process of cattle manure composting so as to provide a theoretical basis for cattle manure harmless treatment.[Method] Both experimental groups supplemented with 2.0% bacterial inhibitor and control groups without bacterial inhibitor were cultured under different temperatures(20,30,37,50,60 ℃)to determine the optimal composing temperature.Under 30 ℃,different bacterial inhibitor doses(0,2.0%,2.5%,3.0%)were added into the compost to obtain the optimal bacterial inhibitor addition dose.[Result] 30,50 and 60 ℃ were ideal temperatures for sterilization of E.coli.Under 30 ℃,E.coli couldn't be detected in 2.5% dose group and 3.0% dose group after culture for 48 h,demonstrating no less than 2.5% bacterial inhibitor should be added.[Conclusion] It has an important significance to enhance the sterilization effects on E.coli by adding CaCN2 into cattle manure compost especially in winter.

Effects of Enzyme on Material Transformation of Cow Dung Compost

[Objective] The aim was to study change of the composition of cow dung compost by adding complex enzyme.[Method] 2.0% enzyme treatment group,1.5% enzyme treatment group and control group were set to analyze temperature,moisture,pH value,crude fiber,TOC,TN,GI during composting.[Result] The results showed that adding complex enzymes could accelerate degradation of organic matter in pre-composting period.Crude fiber of 2.0%,.1.5% enzyme treatment group and control group decreased 49.6%,47% and 29.1% respectively,TOC decreased 41.7%,35.3% and 21.1%,TN decreased 32.6%,26.8% and 19.2%.2.0%,1.5% enzyme treatment groups could reach basic maturity degree at 30 d.[Conclusion] Composting cycle be shortened by adding complex enzymes,which was useful for maturity of cow dung compost.

Study on Compound Substrate Properties with Spent Mushroom Compost and Cattle Manure Compost and Effects on the Growth of Seedlings

[Objective] The purpose was to study the optimum composition ratio of compound substrate with spent mushroom compound （SMC） and cattle manure com- post （CMC） for the seedling growth of tomato, cucumber and watermelon. [Method] With internationally best formula substrate （turf：vermiculite=2：1） used for CK, SMC and CMC were matched according to different proportions to get different substrate whose physical and chemical nutrient properties and their effects on the growth of tomato, cucumber and watermelon were studied by means of plug seeding technolo- gy. [Result] The results showed that the bulk density, porosity and the pH of the compound substrates are all in the ideal condition. However, CMC increased the EC value and the pH of the compound substrates. Compound substrates with high ratio of CMC are not suitable for seedlings. [Conclusion] Tomato and watermelon seedlings grew well in the compost substrate with SMC：CMC=3：1 with no river sand. And the cucumber seedlings grew well in the compost substrate with SMC：CMC=2：1 with 5% volume river sand.

Adsorption Properties of Adsorption Tower Filled with Calcium Superphosphate on NH_3 Emitted from Composting System of Animal Wastes

[Objective] This study aimed to investigate the adsorption properties of the adsorption tower filled with calcium superphosphate on ammonia volatilized with aer- ation. [Method] Adsorption tower filled with calcium superphosphate was adopted as experimental apparatus, which was constructed by poly vinyl chloride （PVC） circular tubes. With hartshorn as the source of ammonia volatilization, the effect of different ratios of height to diameter of the tower filled with equal amount of calcium super-phosphate on ammonia adsorption was investigated. In addition, adsorption tower with height-diameter ratio of 9.9 was selected to adsorb the ammonia emitted from the composting systems of pig manure and chicken manure with optimized and reg- ulated carbon-nitrogen ratio. [Result] Under certain volatilization rate, calcium super- phosphate particles in the adsorption tower could effectively adsorb the ammonia, and the adsorption efficiency was enhanced with the increase of height-diameter ra-tio, which could reach above 90% with height-diameter ratio of more than 1.1; the ammonia emitted from composting systems of pig manure and chicken manure with optimized and regulated carbon-nitrogen ratio could be completely absorbed using adsorption tower with height-diameter ratio of 9.9 filled with calcium superphosphate accounting for about 8% of the weight of composting materials. [Conclusion] Experi- mental results of this study provided reference for the application of adsorption tower filled with calcium superphosphate in the treatment of waste gas emitted from com- posting materials.

Analysis on Bacterial Community Structure in Mushroom(Agaricus bisporus) Compost Using PCR-DGGE

This study aimed to investigate the bacterial communities in mushroom compost piles composed of rice straw, corn stover, and cow dung. Bacterial com- munities of samples at the beginning of composting, at the end of fermentation phase I and II were collected and analyzed using Polymerase Chain Reaction-De- naturing Gradient Gel Electrophoresis （PCR-DGGE） based on 16S rDNA universal primers from Escherichia coli. A total of 56 different clone sequences were obtained （GenBank accession number： KF630598-KF630653）. They were classified into seven phyla and 42 genera. Dominant microflora during composting belonged to phylum Proteobacteria, Firmicutes, and Actinobacteria, with the dominant genera of Bacillus, Paenibacillus, Thermomonospora, Thermasporomyces, Pseudomonas, and Cellvibrio. Bacterial diversity （Shannon index） analysis showed that bacterial species in com- post pile composed mainly of rice straw continuously increased during composting, while those in compost pile composed mainly of corn stover firstly increased and then reduced. Principal component analysis showed that corn stover compost sam- ples at the end of fermentation phase I and phase II were clustered into one group, suggesting that corn stover composted faster than anticipated. In general, rice straw compost has higher bacterial diversity but longer composting time period, while corn stover compost has lower bacterial diversity but shorter composting time period.

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.

Effects of Bacteria and Accessories on Chicken Manure Compost

[Objective] In order to study the influence of bacteria and accessories of chicken manure compost.[Method] The experiment was conducted to investigate the changes of temperature,the quantification of Escherichia coli and the odor during chicken manure compost by adding sawdust,rice husk,yeast and lactic acid bacteria respectively.[Result] The results showed that：（1） The yeast group reached the highest fermentation temperature 67.6 ℃,which was 6.9 ℃ higher than that of lactic acid bacteria group,and the fermentation time of yeast group kept over 55 ℃for 16 days,which was 5 days longer than that of lactic acid bacteria group,both of which were better than that of control group（55.9 ℃,5 days）;（2）The highest fermentation temperature of sawdust group was 2.2 ℃ higher than that of rice husk group,and the fermentation time of sawdust group kept over 55 ℃ was 3 days longer than that of rice husk group;（3） The quantification of E.coli reduced from10^5 to 10^2per gram in both of the yeast group and the lactic acid bacteria group.The odor of the yeast group and the lactic acid bacteria group disappeared in the seventh day and the eighth day respectively.[Conclusion] The results showed that the adding of yeast and sawdust was the best condition for chicken manure composting in this experiment.

模块化滚筒好氧发酵反应器设计与试验

针对现有滚筒式好氧发酵反应器存在腔体容积固定不可调、运行能耗高、尾气余热回用难等问题,基于模块化设计理念,研发了一种模块化滚筒好氧发酵反应器,主要由滚筒、曝气系统、余热回用装置、驱动系统和密封连接件等模块单元组成。对模块化滚筒好氧发酵反应器进行堆肥性能试验,结果表明:高温期持续9 d,发酵持续15 d后种子发芽指数达90%以上,各项指标均满足堆肥腐熟和无害化要求。该设计提高了滚筒好氧发酵反应器加工组装效率,扩大了滚筒好氧发酵反应器适用范围,具有规模可调、分段驱动、分级发酵、精准曝气等优点,可为滚筒好氧发酵反应器堆肥技术发展和应用提供支撑。

牛粪好氧堆肥发酵条件的研究

试验旨在筛选牛粪好氧堆肥发酵的适宜条件。分别选择在不同外界环境温度(24℃、32℃),不同牛粪、秸秆和菜籽粕添加比例(6∶4∶0、8∶1∶1)条件下,将牛粪、秸秆和菜籽粕混合,在混合物中添加0.2%复合微生物菌剂进行好氧堆肥发酵试验。结果发现,32℃下牛粪好氧堆肥发酵效果优于24℃,牛粪、秸秆和菜籽粕(8∶1∶1)混合好氧堆肥发酵效果优于牛粪和秸秆(6∶4)混合。总体以32℃下牛粪、秸秆和菜籽粕按8∶1∶1比例混合好氧堆肥发酵效果最好,粪便腐熟速度快,堆肥品质好,适合当地牛粪进行好氧堆肥发酵。

STUDY ON DEGRADATION OF POLYETHYLENE FILMS CONTAINING ADDITIVES WITH FERROUS ION AT COMPOSTING TEMPERATURES

Polyethylene (PE) films with additives consisting mainly of oleic acid and ferrous ions were subjected to accelerated degradation at simulated composting temperatures.Based on Fourier transform infrared spectroscopy and measurements of mechanical properties and viscosity average molecular weight,the degradation of the films was characterized and the degradation mechanism was discussed.The films containing additives with ferrous ions represent considerable decreases in molecular weight,and the carbonyl groups and hydroperoxides in the aging films show different trends of increase with the aging time.These results indicate that the ferrous ion plays an important role in the degradation of PE films and accelerates the degradation of PE.