Characterization of Organic Matter in Compost Produced with Municipal Solid Wastes: An Italian Approach

Stabilization of the organic matter of a static pile of compost from municipal solid wastes (MSW) under a forced-pressure ventilation composting system was followed for 55 days during winter season. The materials were analyzed according to the official methodologies required by Italian regulations regarding the quality of composts from MSW. The stabilization process of the organic matter was monitored using both the degree of humification (DH), i.e. the ratio between the humified fractions (HA + FA) and the total extractable carbon (TEC), and the electrofocusing technique (EF). The DH increased steadily in compost during stabilization process and converged asymptotically at the end of the period of composting. The EF analyses of the organic extracts of compost from MSW showed a definite trend in the humification process and confirmed the actual evolution of the organic matter composted.     

Carbohydrates as Chemical Constituents of Biowaste Composts and their Humic and Fulvic Acids

The decomposition of organic matter of source-separated biowaste during composting was followed during 18 months. Compost samples were fractionated into three parts: (i) hot water soluble extract (HWE) (ii) bitumen fraction and (iii) humic substances (humic acids (HA) and fulvic acids (FA)). Original compost samples and the HA and FA fractions were hydrolyzed with sulfuric acid for hexoses and pentoses. Quantitative spectrophotometric and qualitative GC/MS analyses of monosaccharides as trimethylsilyl ethers of the corresponding alditols were carried out.

During composting, the amount of HA in the organic matter of the compost increased, the amounts of HWE and bitumen decreased and the amount of the FA fraction changed only a little. Carbohydrates were found to be important constituents of biowaste composts and their HA and FA fractions. Elemental analysis (C, N and H) of compost and HA samples showed an increase in the C:H ratio and in unsaturation of compounds during composting. The decrease in the C:N ratio was marginal.

The amounts of hexoses and pentoses in original compost samples and the HA and FA fractions decreased during composting. The sugar alcohols erythritol, xylitol, L-arabitol, ribitol, L-rhamnitol, L-fucitol, D-mannitol, D-glucitol and galactitol were identified in both the HA and FA fractions. 2-Deoxy-D-erythro-pentitol was identified in one HA fraction and inositol in two FA fractions. An analysis of gas chromatographic data for relative abundances showed that, in every sample except one and in every stage of composting D-glucitol was the main sugar alcohol. In general, the relative amount of D-glucitol decreased during composting, while the relative amounts of all other sugar alcohols increased.

As chemical indicators of compost maturity, carbohydrates would appear to be a important group of compounds. Most informative as a general indicator would be the ratio of the amount of HA to the amount of organic matter in the total compost samples.

According to our studies, the carbohydrates in composts are covalently bound to the structures of FA and HA. Carbohydrate determination clearly deserves more attention in the structural elucidation of FA and HA.     

13C solid-state NMR assessment of decomposition pattern during co-composting of sewage sludge and green wastes

The fate of organic matter during composting is poorly understood. Therefore, we analysed composts of sewage sludges and green wastes (44 samples representative of 11 stages of biodegradation) by conventional chemical methods: pH, humic (HA) and fulvic acid (FA) content, C, N and organic matter (OM) content, and by ¹³C CPMAS NMR to assess the decomposition process of the organic matter. Chemical changes clearly occurred in two phases: first, decomposition of OM during the first 2 months was characterized by decreased C/N ratios, OM content and increased pH; and second, a humification process with increased HA/FA ratios. NMR spectrum changes confirmed this pattern, with an increase in aromaticity and a decrease in alkyl C. A decrease of syringyl to guaiacyl ratio (S/G), a sign of lignin transformation, also indicated humification during composting. NMR spectroscopic properties of composts were also studied by means of principal components analysis (PCA) and revealed changes according to the degree of compost maturation. The factorial map presents a chronological distribution of composts on the two first principal components. The influences of eight chemical factors on the PCA ordination of composts as monitored by their evolution by NMR were also studied by multivariate analyses. PCA clearly indicated two phases: the rapid decomposition of organic matter followed by the formation of humic‐like substances. The first phase, that is ‘new’ composts, was strongly correlated with OM contents, pH and C/N ratios whereas the second phase, corresponding to ‘old’ compost, was correlated with pH, HA content and HA/FA ratio. These results confirm that knowledge of the formation of humic substances is indispensable to suitable monitoring of the composting process.     

Organic Matter Evolution Index (OMEI) as a Measure Of Composting Efficiency

The significance of the organic matter evolution index (OMEI) related to the composting process degree was tested on a full-scale windrow process for 239 days. Analytical data from many samples collected during the process and kinetics were in agreement regarding the insufficient degree of stability and maturity reached by the compost obtained. As expected, the OMEI at the end of the process was low (OMEI = 0.46) confirming its validity to composting degree evaluation. New analytical methods for humic substances quantification were developed by monitoring humic acids concentration versus composting time and ligno-humic fraction.     

Evaluation of the stabilization level of pig organic waste: Influence of humic‐like compounds

Abstract

The evolution of the organic matter during the maturation of solid samples of pig sludges and pig manure composted with straw was followed. A sample of pig sludge about 15 years old also was characterized for comparison. The organic matter of the composts and sludges was extracted and the humic (HA) and fulvic acids (FA) were separated. The organic carbon in the total extract (TEC) in the fulvic fraction and in the humic fraction was determined in order to evaluate the stabilization level of the organic matter using some humification parameters. The nature of the organic extract also was evaluated by characterization with analytical isoelectric focusing (IEF). The results confirm that the degree of humification (DH) decreases during the first period of maturation of the organic matter, because of the degradation of humic and fulvic‐like compounds contained into the raw organic materials, while then it increases progressively for all the maturation period. The data collected in this study confirm that the FA fraction could be the main cause of the lack of regularity in the trend of increasing DH as maturation progresses. The FA/TEC ratio infact decreases progressively for all the maturation period, while the HA/TEC ratio increases. The results obtained in the IEF characterization confirm the validity of this analytical technique. Moreover, the results do not appear to be affected by the presence of the humic‐like compounds. The presence of the bands focused at the higher pH values appear to be directly related to the stabilization of the organic material.     

Chemical Evaluation of Sewage Sludge Composting as a Mature Indicator for Composting Process

Several chemical parameters were studied during a 100 daysperiod in order to identify parameters that can be used asindicators of compost maturity. One treatment was a mixture ofsewage sludge and sawdust (TS); another was a mixture of sewagesludge, pig manure and sawdust (TS-PM). The pH of water extractsincreased during the thermophilic phase and then decreased in twotreatments. While the electrical conductivity (EC) decreasedthroughout the composting time. The 4.99% in the change ofvolatile matter of TS-PM was higher than 1.73% in that of TS,at the same time, the change of organic carbon were 5.04% inTS-PM more than 3.82% of TS. Total nitrogen content in TS andTS-PM had a markedly increase tendence during composting, andthe change in TS-PM was very more obvious than in TS, soreduction of C/N ratio in TS-PM was higher than in TS, C/Nratio of TS-PM and TS was 14.39 and 18.57 in mature production,respectively. Carbon content in HA plus FA and HA in twocomposts decreased from 0 to 100 day, but carbon content of FAdecreased, so HA-C/FA-C ratio, HR, HI has a markedly increase inTS and TS-PM, and the parameters in TS-PM were higher than inTS. The points expressing maturity degree in TS-PM was more inTS. The nitrogen content of HA plus and HA showed a increasedtendence in TS and TS-PM, the change of nitrogen of thesefractions in TS-PM was higher than in TS, so C/N ratio of allfractions including HA plus FA, HA and FA, indicated a reductiontendence, and the refuction in FA was larger than in HA. E4/E6ratio of HA plus FA and HA decreased during composting, and one FA was increase. E4/E6 ratio of HA plus FA and HA in TS-PM wasvery smaller than in TS, HA in TS-PM was a larger molecular sizethan HA in TS. The changes of organic matter compositions incomposting: the crude fat and carbohydrates had a markedlyreduction and cellulose plus hemicellulose had a slight decrease;crude protein and lignin content in TS and TS-PM had an increasetendence.     

菌剂对鸡粪堆肥腐殖质含量品质的影响

腐殖质是评价堆肥品质的重要因素,该文利用鸡粪和秸秆为原料进行高温好氧堆肥,设计接种菌剂和不接种菌剂(对照)2个处理,研究菌剂添加对堆肥腐殖质形态、含量、品质的影响。结果表明:与对照相比,接种菌剂可以加快有机物的降解,矿质化时间缩短14d,菌剂具有良好的保碳效果,总有机碳含量提高了16.1%,同时总腐殖酸、游离腐殖酸以及水溶态腐殖酸及胡敏酸的含量,分别提高了38.7%,45.7%、39.0%及54.9%。接种菌剂可以提高腐殖酸的活性,堆肥结束后,接种菌剂处理的游离腐殖酸和水溶性腐殖酸含量均增加,而对照处理的含量均降低;堆肥可以提高腐殖酸质量,堆肥结束后两个处理总腐殖酸含量均下降但是缩合度、腐殖化率、腐殖化指数及胡敏酸百分比均提高,特别是添加菌剂的处理腐殖化程度明显高于对照。说明了菌剂可以增加堆肥腐殖质含量,提高腐殖质缩合度、芳构化程度及活性。     

Evolution of Humic Acid Molecular Weight As an Index of Compost Stability

This paper proposes an index for the evaluation of compost maturity based on the evolution of molecular weights of humic acids (HA) during composting. The evolution of HA molecular weight was followed during the composting of both olive mill wastewater (OMW) and olive mill pomace (OMP). The wastes were composted in forced aeration static piles. Samples of the compost were collected at different times during composting. The elution profiles of HA obtained by gel filtration (Sephadex G-150) showed the disappearance of fractions with molecular weights ≤ 50 KDa and the contemporary increase of fraction with molecular weights ≥ 10² KDa. In this range, two fractions can be separated: the first one (A1) with molecular weights greater than 10² KDa and below 2 10² KDa, and the second one (A2) with molecular weight greater than 2 10² KDa. During composting, the ratio A2/A1 tends to reach a constant value which indicates the evolution toward the polymerization of HA. The ratio A2/A1 was named HAEI (Humic Acid Evolution Index). It varies with the material composted and the composting process and represents the maximum possible degree of HA polymerization. A comparison between HAEI and the usually used maturity indexes is also presented.     

鸡粪腐解过程中不同溶性腐殖质的动态变化

以鸡粪为材料,添加不同比例的铜、锌进行腐解试验,研究了腐解过程中不同溶性(游离态、松结合态、紧结合态)腐殖质及其组成的动态变化和粪肥中所添加高浓度Cu和Zn对不同提取性的腐殖质及其组成的影响.随着腐解的进行,鸡粪中可提取性的有机碳总体呈下降趋势,与总有机碳(TOC)含量变化趋势一致.在整个腐解过程中,NaOH液浸提提取松结合态腐殖质主要部分,占50%～70%.随着粪肥样品锌含量的增加,松结合态腐殖质在整个腐解期平均分配含量有所增加,而NaOH-Na_4P_2O_7液浸提提取紧结合态腐殖质则有所减少,H_2O浸提提取游离态腐殖质变化较小.随着粪肥样品铜含量的增加,松结合态腐殖质在整个腐解期平均分配含量有所增加,而游离态腐殖质则有所减少,但紧结合态腐殖质变化较小.粪肥中Cu、Zn的浓度高低会影响游离态腐殖质中富里酸(FA)和胡敏酸(HA)占TOC比例的变化趋势,铜含量较高的处理样品的松结合态腐殖质FA/TOC(2: 1和3: 1)下降幅度较大,随后皆有上升趋势,30 d后处于近水平状态,铜含量高的处理样品松结合态腐殖质HA/TOC上升幅度较大,随后呈下降趋势.铜含量较高的处理样品的紧结合态腐殖质FA/TOC(2: 1和3: 1)下降幅度较大,随后皆有上升趋势,45 d后又有所下降.在腐解过程中,各处理粪肥样品紧结合态腐殖质HA/TOC曲线表现"马鞍"形状.游离态、松结合态和紧结合态腐殖质的HA/FA分别与其对应的HA/TOC显极显著正相关关系.     

鸡粪堆肥腐熟度参数及波谱的形状研究

本研究从农业固体废弃物资源化利用角度出发,设计了以鸡粪、玉米秸秆为原料和填充料的高温堆肥体系,应用物理分析法、化学分析法、波谱分析法和植物生长分析法研究了高温堆肥的腐熟度参数及指标。结果表明,温度是表征高温堆肥腐熟度的最直接参数。随着堆肥进程的进行,C/N、NH4+-N含量呈下降趋势,HA/FA呈上升趋势,它们能较好地反映高温堆肥腐熟程度,可以作为堆肥的腐熟指标。堆肥胡敏酸可见光谱、红外光谱、核磁共振光谱对堆肥有机质结构变化和腐熟度判定具有重要的参考价值;堆肥过程中堆肥腐熟指标变化与种子发芽率变化规律具有一定的相关性。     

Physical,Chemical and Biological Properties of an Accelerated Cassava Based Compost Prepared Using Different Ratios of Cassava Peels and Poultry Manure

Monitoring the physical, chemical and biological properties during accelerated composting enables concise determination of its stability and maturity. Determination of physical parameters such as pH, moisture and temperature, chemical parameters such as total nitrogen (N), phosphorus (P), potassium (K), organic matter and humic acid as well as biological parameters such as microbial count and carbon dioxide (CO₂) evolution was carried out during a four (4) week composting period, The trend observed for pH showed the mesophilic and thermophilic phases and a similar trend was observed for the compost temperature. Intermittent increase and decrease was observed for total N, P, K as well as for the fungal and bacterial population. A direct relationship was observed among the bacterial population, CO₂ evolution and humic acid. However, composting for four (4) weeks produced a stable compost, which was evident through the physical observation of the final product and the results obtained for the chemical and biological parameters.     

Macromolecule‐P associations and inositol phosphates in some chilean volcanic soils of temperate regions

Abstract

Total organic P, humic and fulvic acid‐P associations and inositol phosphates in nine volcanic soils of southern Chile were determined. The concentration of organic P (Po) ranged from 654 to 1942 ppm accounting for 49% to 64% of total soil P. Phosphorus associated to humic (HA‐P) and fulvic acids (FA‐P) accounted for 51–68% and 32–49% of Po, respectively. Inositol penta‐ and hexaphosphates represented 42% to 67% of Po suggesting that significant amounts are associated with both humic and fulvic acids. Po content was significantly correlated to organic C, total soil P and HA‐P. HA‐P and FA‐P fractions obtained from the most representative soil were examined by dyalisis and gel filtration. While approximately 96% of HA‐P presented a molecular weight higher than 100,000 daltons, 53% of FA‐P had a molecular weight under 12,000 daltons. It is suggested that these more labile organic P forms would be more easily mineralized, thus increasing the available P pool.     

Utilization of Compost Increases Organic Carbon And Its Humin,Humic and Fulvic Acid Fractions In Calcareous Soil

Organic carbon sustainability in a gravelly calcareous soil is a great challenge under the humid conditions of south Florida. The beneficial effects of compost utilization on soil fertility prompted an investigation on (i) accumulation of total organic carbon and (ii) the soil organic carbon (SOC) in humin, humic acid (HA) and fulvic acid (FA) fractions in a gravelly calcareous soil amended with composts or inorganic fertilizer. In 1996 and 1998, compost from municipal solid waste (MSW) (100% MSW), Bedminster cocompost (75% MSW and 25% biosolids) and biosolids compost (100% biosolids) at 72, 82.7 and 15.5 Mg ha^?1, respectively, were each incorporated in soil beds and inorganic fertilizer (6-2.6-10) NPK at 2.8 Mg ha^?1. A control (no amendment) treatment was also included. Total organic carbon and various fractions of soil organic carbon were determined in two depths (0-10 and 10-22 cm) for both soil particles (< 2mm) and pebbles (> 2mm). Inorganic and organic soil amendments had decreased soil pH and increased soil electrical conductivity (EC) 19 months from initial application. Total organic carbon contents in soil particle were 4-, 3-, and 2-fold higher in MSW compost, Bedminster cocompost and biosolids compost treatments, respectively, than those in fertilizer treated or non-treated soils. MSW compost increased total organic carbon in pebbles by 4- and 3-fold in the 0-10 and 10-22 cm deep layers, respectively, more than other treatments. The soil organic carbon accumulation decreased with depth in all treatments in soil particles, but did not in pebbles. Amending soils with MSW compost significantly increased the organic carbon in humin, HA and FA fractions more than those treated with inorganic fertilizer or non-amended. MSW compost has a potential to be used as a soil amendment to increase and sustain the organic carbon in calcareous soils of south Florida.     

Valorization of Mediterranean Livestock Manures: Composting of Rabbit and Goat Manure and Quality Assessment of the Compost Obtained

The purpose of this work was to study the viability of the composting of goat (Capra aegagrus hircus) manure (GM) and rabbit (Oryctolagus cuniculus) manure (RM) and to evaluate the quality of the compost obtained. For this, a mixture of these manures was prepared at a goat/rabbit ratio of 44:56 (fresh-weight basis) and 50:50 (dry-weight basis). The mixture was composted by the Rutgers static pile composting system, with forced aeration and controlled temperature. Throughout the composting process, the temperature was monitored and physicochemical, chemical, and biological parameters were evaluated. The temperature evolution showed the suitable development of the composting process, with thermophilic values (>40 °C) maintained for more than 90 days. The finished compost had stabilized and humified organic matter. However, the pH (9.4) and the salinity (EC of 13.4 dS/m) could limit its potential agricultural use.     

The Impact of Various Contaminants on the Trace Metal Content of Compost

The trace metal content of municipal solid waste (MSW) compost affects the quality and potential end uses of the finished product. The impact of typical contaminants found in the organic fraction of MSW on the trace metal content of compost was investigated. Contaminants including alkaline batteries, galvanized nails, zinc-plated screws, copper wires, and electronic cables were exposed to a thermophilic composting process for three weeks. The increase in trace metal content in the compost product was measured at the end of the composting process. The results showed that low-quality alkaline batteries, galvanized nails, zinc-plated nails, and copper wires had a significant impact on the zinc, copper, arsenic, lead, and cobalt contents of compost. Copper wires showed the highest impact on copper content, which was 52% of the Canadian Council of Ministers of the Environment (CCME) Category A limit in the final compost. Galvanized nails contributed to final levels of zinc reaching 30% of the CCME Category A limit. To ensure that CCME Category A criteria can be achieved, it is recommended that contaminants made from bare copper or coated with zinc be removed from the composting feedstock.     

Changes in the Apolar Organic Fraction Through The Composting Process

The organic fraction soluble in different organic solvents with increasing polarity was studied during the composting process, following its transformation from raw material until the stable final product with the aim to establish new quality indices of compost maturity. All apolar fractions during the composting process had a reduction higher than 50%. Part of the compounds have been utilized by the microflora as energetic material and to perform the biotransformations, and part has been transformed in molecule like the humic molecules. However, in our conditions a relevant part (36%) of apolar material is recovered at the end of the biotransformation. The spectroscopic analysis indicates in the final product an increase of lipidic compounds, as esters or acids as well as hydrocarbons with longer linear aliphatic chain.     

Cost Considerations of Municipal Solid Waste Compost: Production versus Market Price

? As more composting facilities come on line across the United States, and a wider spectrum and greater quantity of organic materials are composted, the need to develop a variety of markets for their end products, i.e., compost or mulch, will become ever more critical to the future growth potential for composting and its success. It is often stated that high quality compost will always find a market. However, the economic implications of producing a high quality compost need to be better understood. Publicly and privately operated composting facilities need to compare the costs for building or improving their composting programs to the associated economic returns, i.e., the increased selling price for their product (or, if the product is not sold, the increased avoided cost for what the compost/mulch product is substituted for) and other economic implications.

The scarcity of published information on the costs of producing marketable compost at U.S. municipal solid waste composting (MSW) facilities is largely due to the minimal experience in producing and marketing these composts in this country. In order to improve both facility operation and compost quality, most facilities that have operated for more than one year are making modifications, particularly in the type of feedstock, front-end process, composting process, and final compost processing. A summary of such changes is presented for nine U.S. plants, but little information is available on the costs of these modifications, nor their impact on compost quality. Information is also presented about the European experience with MSW composting, emphasizing the importance of producing better quality compost, and the need to fully account for the added costs associated with producing a higher quality compost.     

Evaluation of maturity and stability parameters of composts prepared from farm wastes

A composting experiment was carried out to study changes in physical [color, odor, temperature, organic matter (OM) loss], chemical [C:N ratio, water-soluble organic carbon (C_w):organic N (N_org) ratio, NH₄ ⁺-N and NO₃ ^?-N, humic acid (HA):fulvic acid (FA) ratio, humification index (HI) and cation-exchange capacity (CEC):total organic carbon (TOC) ratio)] and biological [seed germination index (GI)] parameters to assess compost maturity and stability over a period of 150 days. Five composts were prepared using a mixture of different farm wastes with or without enrichment of N, rock phosphate (RP) and microorganism (MO) inoculation. All the composts appeared to change to a granular and dark grey color without foul odor, and attained a constant temperature with no measurable changes (ambient level) at 120 days of composting. Correlation analysis showed that the optimal values of the selected parameters for our experimental conditions are as follows: organic matter loss > 42%, C:N ratio < 15, HA:FA ratio > 1.9, HI > 30%, CEC:TOC ratio > 1.7 and C_w:N_org ratio < 0.55. Composts enriched with N + RP or N + RP + MO matured at 150 and 120 days, respectively, whereas composts without any enrichment or enrichment with N or RP + MO did not mature even at 150 days of composting.     

菌剂DF-1对啤酒厂污泥与鸡粪堆肥的影响

为了探讨功能性菌剂对堆肥化进程的影响,并为加快啤酒厂污泥与鸡粪堆肥化进程和减少臭气提供理论依据,将自制菌剂DF-1接种至啤酒厂污泥与鸡粪的堆体中,以不接种堆体为参照,测定了堆肥化过程中各参数的变化及菌剂DF-1中优势微生物变化情况。结果显示：两个堆体废气中NH3浓度均呈现先上升后下降的变化趋势,H2S浓度则呈现持续下降的变化情形;不接种堆体NH3浓度至堆肥腐熟期仍为0.39 mmol/m3,而接种堆体第10天为1.25 mmol/m3,此后无法检出;不接种堆体中H2S浓度在堆肥第22天仍为0.7 mg/L;而接种菌剂堆体第10天为0.48 mg/L,此后无法检出。接种菌剂DF-1不但能降低堆体水分含量,而且其堆体腐熟期TN含量高于未接种菌剂DF-1的堆体,说明接种菌剂后不但能有效减少臭气,而且有利于堆肥产品后期烘干制粒和优质高效有机肥的产生。菌剂DF-1中优势菌种乳酸乳球菌、热带假丝酵母及绿色木霉在堆肥过程中存在交替演变。     

超高温预处理装置及其促进鸡粪稻秸好氧堆肥腐熟效果

为提高畜禽粪便堆肥效率和质量,设计了一种超高温预处理好氧堆肥工艺,并以鸡粪和稻秸为原料,进行了为期62 d的堆肥试验。设置了3个处理,即:高温好氧堆肥(CK);超高温(85℃)预处理4 h+高温好氧堆肥(HPC);超高温(85℃)预处理4 h+接种0.5%新鲜鸡粪+高温好氧堆肥(I-HPC)。监测了堆体的温度、含水率、pH值等参数的变化情况,并以C/N、可溶性有机碳(dissolved organic carbon,DOC)、铵态氮、硝态氮、腐殖化指数(humification index,HI)、种子发芽指数(germination index,GI)为指标评价了堆肥腐熟度和质量。结果表明,与CK相比,超高温预处理可以提高后续堆料升温速率和最高温度、延长高温期天数、缩短堆肥周期,I-HPC、HPC的最高温度比CK分别高出13.6、12.8℃,≥50℃的天数分别比CK多3、2 d。但与HPC相比,接种新鲜鸡粪并没有加快后续堆肥进程。超高温预处理后,物料容重由0.81 g/cm~3下降为0.72 g/cm~3、pH值下降了1~2;而DOC质量分数由106 g/kg上升到124 g/kg;总挥发性脂肪酸(total volatile fatty acids,TVFAs)、NH_4~+-N质量分数分别为预处理前的3.2倍、2.45倍。HPC、I-HPC堆体有机质降解速率常数分别为0.0501、0.0534 d-1,比CK(0.00143 d-1)大,因此,HPC、I-HPC堆肥产品的TOC质量分数(182.1、192.1 g/kg)分别比CK(205.3 g/kg)低;TN质量分数(19.70、21.28 g/kg)比CK(17.96 g/kg)高;腐殖化指数(0.77、0.71)比CK(0.64)高。但HPC、I-HPC堆肥产品之间TN质量分数、腐殖化指数无显著差异。因此,超高温预处理好氧堆肥法能明显缩短堆肥周期、提高堆肥产品质量,具有较大的应用潜力。