Characterization of dairy cattle manure/wallboard paper compost mixture

The aim of this research was to evaluate the use of manufacturing wallboard paper scraps as an alternative bulking agent for dairy cattle manure composting. The characteristics of the composting process were studied based on the changes in physico-chemical parameters and final compost quality. Composting of dairy cattle manure with wallboard paper was performed in a 481-L cylindrical reactor with vacuum-type aeration. Rapid degradation of organic matter was observed during the thermophilic stage of composting due to high microbial activity. High temperature and alkaline pH conditions promoted intense ammonia emission during the early stage of composting. The number of mesophilic and thermophilic microorganisms were found to be affected by changes in temperature at different composting stages. The total nitrogen (N), phosphorus (P), potassium (K), and sodium (Na) concentrations of the mixture did not change significantly after 28days of composting. However, the presence of gypsum in the paper scraps increased the calcium content of the final compost. The wallboard paper had no phyto-inhibitory effects as shown by high germination index of final compost (GI=99%).     

The fate of a genetically modified Pseudomonas strain and its transgene during the composting of poultry manure

The fate of the genetically modified (GM) Pseudomonas chlororaphis strain 3732 RN-L11 and its transgene (lacZ insert) during composting of chicken manure was studied using plate count and nested polymerase chain reaction (PCR) methods. The detection sensitivity of the nested PCR method was 165 copies of the modified gene per gram of moist compost or soil. Compost microcosms consisted of a 100-g mixture of chicken manure and peat, whereas soil microcosms were 100-g samples of sandy clay loam. Each microcosm was inoculated with 4 x 1010 CFU of P. chlororaphis RN-L11. In controlled temperature studies, neither P. chlororaphis RN-L11 nor its transgene could be detected in compost microcosms after incubation temperature was elevated to 45 degrees C or above for one or more days. In contrast, in the compost microcosms incubated at 23 degrees C, the target organism was not detected by the plate count method after 6 days, but its transgene was detectable for at least 45 days. In compost bins, the target organism was not recovered from compost microcosms or soil microcosms at different levels in the bins for 29 days. However, the transgene was detected in 8 of the 9 soil microcosms and in only 1 of the 9 compost microcosms. The compost microcosm in which transgene was detected was at the lower level of the bin where temperatures remained below 45 degrees C. The findings indicated that composting of organic wastes could be used to reduce or degrade heat sensitive GM microorganisms and their transgenes.     

Persistence of Mycobacterium avium subsp. paratuberculosis and other zoonotic pathogens during simulated composting, manure packing, and liquid storage of dairy manure

Livestock manures contain numerous microorganisms which can infect humans and/or animals, such as Escherichia coli O157:H7, Listeria monocytogenes, Salmonella spp., and Mycobacterium avium subsp. paratuberculosis (Mycobacterium paratuberculosis). The effects of commonly used manure treatments on the persistence of these pathogens have rarely been compared. The objective of this study was to compare the persistence of artificially inoculated M. paratuberculosis, as well as other naturally occurring pathogens, during the treatment of dairy manure under conditions that simulate three commonly used manure management methods: thermophilic composting at 55 degrees C, manure packing at 25 degrees C (or low-temperature composting), and liquid lagoon storage. Straw and sawdust amendments used for composting and packing were also compared. Manure was obtained from a large Ohio free-stall dairy herd and was inoculated with M. paratuberculosis at 10(6) CFU/g in the final mixes. For compost and pack treatments, this manure was amended with sawdust or straw to provide an optimal moisture content (60%) for composting for 56 days. To simulate liquid storage, water was added to the manure (to simulate liquid flushing and storage) and the slurry was placed in triplicate covered 4-liter Erlenmeyer flasks, incubated under ambient conditions for 175 days. The treatments were sampled on days 0, 3, 7, 14, 28, and 56 for the detection of pathogens. The persistence of M. paratuberculosis was also assessed by a PCR hybridization assay. After 56 days of composting, from 45 to 60% of the carbon in the compost treatments was converted to CO2, while no significant change in carbon content was observed in the liquid slurry. Escherichia coli, Salmonella, and Listeria were all detected in the manure and all of the treatments on day 0. After 3 days of composting at 55 degrees C, none of these organisms were detectable. In liquid manure and pack treatments, some of these microorganisms were detectable up to 28 days. M. paratuberculosis was detected by standard culture only on day 0 in all the treatments, but was undetectable in any treatment at 3 and 7 days. On days 14, 28, and 56, M. paratuberculosis was detected in the liquid storage treatment but remained undetectable in the compost and pack treatments. However, M. paratuberculosis DNA was detectable through day 56 in all treatments and up to day 175 in liquid storage treatments. Taken together, the results indicate that high-temperature composting is more effective than pack storage or liquid storage of manure in reducing these pathogens in dairy manure. Therefore, thermophilic composting is recommended for treatment of manures destined for pathogen-sensitive environments such as those for vegetable production, residential gardening, or application to rapidly draining fields.     

Change in Microbial Numbers during Thermophilic Composting of Sewage Sludge with Reference to CO(2) Evolution Rate

Dewatered sewage sludge was composted in a laboratory-scale autothermal reactor in which a constant temperature of 60 degrees C was kept as long as possible by regulating the air feed rate. The change in CO(2) evolution rate was measured continuously from the start up through the cessation of compositing. The succession of mesophilic bacteria, thermophilic bacteria, and thermophilic actinomycetes was also observed during the composting. Specific CO(2) evolution rates of thermophilic bacteria and actinomycetes in the constant-temperature region of 60 degrees C were assessed quantitatively. It was found that the CO(2) evolution rate was attributed to thermophilic bacteria at the initial stage of 60 degrees C and to thermophilic actinomycetes at the later stage of 60 degrees C.     

Enhancement of the thermophilic stage in cattle waste composting by addition of tofu residue

The microbial degradation and temperature rise during the composting of a cattle waste and rice straw mixture blended with tofu (soybean curd) residue was investigated using an insulated and unheated in-vessel composter (effective volume, 12 1) and a static pile with passive aeration. The addition of 11% (dry weight basis) of tofu residue shortened the time required for temperature to reach the thermophilic phase and increased the duration of the temperatures above 55 degrees C significantly, but the maximum temperature was not affected by the additive level. As shown by the change in BOD, most of the easily biodegradable matter in the tofu residue was consumed during 12 days of composting. The same results were observed in the temperature profile of the static pile with passive aeration. Tofu residue addition yielded a higher maximum temperature and a nearly two times longer duration of temperatures above 55 degrees C in almost all locations of the pile. The use of tofu residue as a co-composting material would promote thermophilic degradation throughout the entire composting mass.     

Allantoin-N concentration changes and analysis of the influencing factors on its changes during different manure composting

Allantoin is one of important nitrogenous compounds in manure. In this study, the simulation experiment of aerobic composting was adopted to explore concentration changes, degradation and relevant influencing factors of allantoin-N during six manure composting. The result showed that the allantoin-N concentration was markedly different among different manures. The various livestock and poultry excreted 1.92-11.14gkg(-1) allantoin-N which accounted for 9.98-32.27% of the total excreted nitrogen. The changing trend of the allantoin-N concentration firstly increased (for 0-14 days), then decreased (for 14-70 days) during different manure composting, and the allantoin-N concentration after composting was lower than the initial allantoin-N concentration in all manure composting. During allantoin degradation for 14-70 days of composting, the half-life of allantoin-N was 57.76 days in broiler manure, 46.21 days in layer-hen manure, 27.73 days in hog manure, 25.67 days in sow manure, 38.51 days in young pig manure and 15.75 days in dairy manure, and the sequence in the half-life was chicken manure>pig manure>dairy manure. Allantoin degradation conformed to first-order kinetics. Through the correlation analysis, hippuric acid, hydrolyzable nitrogen, amino acid-nitrogen, HUN fraction, NO(3)(-)-N and total hydrolyzable nitrogen could be closely related to allantoin-N transforming during composting. Humification could be the main influencing factor for reducing allantoin-N concentration during composting.     

Comparison of composting, storage and urea treatment for sanitising of faecal matter and manure

To close the loop of nutrients in a safe way, the loop of pathogens has to be broken. By sanitising organic fertilisers derived from faeces and manure, the first step in the disease transmission chain is broken. Two alternatives for this treatment, thermophilic composting and ammonia-based treatment, were evaluated and compared to storage treatment. Thermal composting of faecal matter and food waste resulted in a treatment temperature of over 65 degrees C in a 90 L reactor. By using insulation and turning the compost three times during the high temperature period, it is possible to ensure a 5 log(10) reduction of pathogens. Small scale composting of the same material indicated less efficient reduction of faecal bacteria at temperatures around 50 degrees C. In the chemical treatment tested, an addition of 3% N-NH(3) increased the pH to above 9 within 1h and resulted in a good reduction in the indicator organisms for bacteria (Salmonella spp. and faecal coliforms D(r)<0.7 days, Enterococcus spp. D(r)<3 days). Lower addition rates resulted in a longer treatment period needed. The storage period tested resulted in slow reduction of faecal coliforms, Salmonella spp. and Enterococcus spp.     

Comparison of bacterial community structure and dynamics during the thermophilic composting of different types of solid wastes: anaerobic digestion residue,pig manure and chicken manure

This study investigated the impact of composting substrate types on the bacterial community structure and dynamics during composting processes. To this end, pig manure (PM), chicken manure (CM), a mixture of PM and CM (PM + CM), and a mixture of PM, CM and anaerobic digestion residue (ADR) (PM + CM + ADR) were selected for thermophilic composting. The bacterial community structure and dynamics during the composting process were detected and analysed by polymerase chain reaction–denaturing gradient gel electrophoresis (DGGE) coupled with a statistic analysis. The physical-chemical analyses indicated that compared to single-material composting (PM, CM), co-composting (PM + CM, PM + CM + ADR) could promote the degradation of organic matter and strengthen the ability of conserving nitrogen. A DGGE profile and statistical analysis demonstrated that co-composting, especially PM + CM + ADR, could improve the bacterial community structure and functional diversity, even in the thermophilic stage. Therefore, co-composting could weaken the screening effect of high temperature on bacterial communities. Dominant sequencing analyses indicated a dramatic shift in the dominant bacterial communities from single-material composting to co-composting. Notably, compared with PM, PM + CM increased the quantity of xylan-degrading bacteria and reduced the quantity of human pathogens.     

猪粪好氧堆制不同阶段氧气含量变化特征

研究了不同堆肥阶段氧气浓度和耗氧速率的变化特征．结果表明,不同堆肥阶段通风补充氧气所需的时间很短,各阶段通风后氧气浓度都恢复到17％以上．堆肥升温阶段、高温阶段初期耗氧速率高,达900μl·L^-1·s^-1以上;随着堆肥的进行,耗氧速率逐渐降低,经过5～7d的持续高温期后,耗氧速率下降到100μl·L^-1·s^-1以下,堆肥基本腐熟．根据耗氧堆肥的氧气动态变化特征,提出了相应的通风策略．     

Composting of poultry manure and wheat straw in a closed reactor: optimum mixture ratio and evolution of parameters

The main objectives of this work were to investigate the evolution of some principal physico-chemical properties (temperature, carbon dioxide, oxygen, ammonia, pH, electrical conductivity, organic matter) and microbial population (mesophilic and thermophilic bacteria and fungi) during composting poultry manure with wheat straw in a reactor system, and to evaluate the optimum mixture ratio for organic substrate production. The experiments were carried out in four small laboratory reactors (1 l) and one large reactor (32 l) under adiabatic conditions over 14 days. During the process the highest temperature was 64.6°C, pH varied between 7.40 and 8.85, electrical conductivity varied between 3.50 and 4.31 dS m⁻¹ and the highest value of organic matter (dry weight) degradation was 47.6%. Mesophilic bacteria and fungi predominated in the beginning, and started the degradation with generation of metabolic heat. By increasing the temperature in reactors, the number of thermophilic microorganisms also increased, which resulted in faster degradation of substrate. The application of a closed reactor showed a rapid degradation of manure/straw mixture as well as a good control of the emissions of air polluting gases into atmosphere. The results showed that the ratio of manure to straw 5.25:1 (dry weight) was better for composting process than the other mixture ratios.     

Effect of high compost temperature on enzymatic activity and species diversity of culturable bacteria in cattle manure compost

To clarify the characteristics of thermophilic bacteria in cattle manure compost, enzymatic activity and species diversity of cultivated bacteria were investigated at 54, 60, 63, 66 and 70 degrees C, which were dependent on composting temperature. The highest level of thermophilic bacterial activity was observed at 54 degrees C. Following an increase in temperature to 63 degrees C, a reduction in bacterial diversity was observed. At 66 degrees C, bacterial diversity increased again, and diverse bacteria including Thermus spp. and thermophilic Bacillus spp. appeared to adapt to the higher temperature. At 70 degrees C, bacterial activity measured as superoxide dismutase and catalase activity was significantly higher than at 66 degrees C. However, the decomposition rate of protein in the compost was lower than the rate at 66 degrees C due to the higher compost temperature.     

Composting rapidly reduces levels of extractable oxytetracycline in manure from therapeutically treated beef calves

Oxytetracycline (OTC) is a broad-spectrum antibiotic used in livestock production. The widespread use and relative persistence of OTC may encourage development of antibiotic-resistant bacteria. The objective of this study was to determine whether composting would substantially reduce the concentration of OTC found in manure from medicated animals. The effect of OTC on composting was also investigated. Five beef calves were medicated for 5 days with 22 mg/kg/day of OTC. Approximately 23% of the OTC fed to the calves was recovered in the manure. Manure samples collected from calves prior to and after medication were mixed with straw and woodchips, and aliquots of the subsequent mixtures were treated in laboratory composters for 35 days. In addition, aliquots of the OTC-containing mixture were incubated at 25 degrees C or sterilized followed by incubation at 25 degrees C. The presence of OTC did not appear to affect composting processes. Within the first six days of composting, levels of extractable OTC in the compost mixture decreased from 115+/-8 microg/g dry weight to less than 6+/-1 microg/g dry weight (a 95% reduction). In contrast, levels of extractable OTC in room temperature incubated and sterilized mixtures decreased only 12-25% after 37 and 35 days, respectively. Levels of total heterotrophic bacteria and OTC-resistant bacteria in the finished compost mixture were roughly 30-fold higher and 10-fold lower, respectively, than levels in the mixture prior to composting. Although the basis of the OTC disappearance during composting is not known, the preponderence of OTC-sensitive bacteria and the decrease of OTC-resistant bacteria in the finished compost suggests that OTC residues have been rendered biologically inactive or unavailable.     

Co-composting solid swine manure with pine sawdust as organic substrate

The main objectives of this work were to investigate the evolution of the principal physicochemical properties, i.e., bulk temperature, pH, electrical conductivity (EC), moisture content, total organic matter, total nitrogen and total phosphorus, in co-composting pine sawdust with increasing percentages of fresh solid swine manure, and thus to evaluate the most desirable manure proportion for producing organic substrates in consideration of the quality of the resulted compost. The composting was in four identical 100.5l lab vessels, using 5% each tea leaves and herb residues as conditioners. The swine manure was added in the trials at 20%, 30%, 40%, respectively, and was substituted in the control with 30% lake sludge corrected by 0.5% urea. The initial humidity of each treatment was 60+/-2%. While being aerated actively at approximately 0.3m(3)/min at intervals of 10 min/h, the mixture was composted for 29 days. The results indicated that N and P decomposition primarily occurred in the mesophilic phase, while organic carbon decomposed in the thermophilic phase and 30% swine manure with initial C/N ratio of about 40 was more desirable for composting organic substrates.     

Effect of aeration on composting of date palm residues contaminated with Fusarium oxysporum f.sp. albedinis

Composting of date palm (Phoenix dactylifera L.) residues contaminated with Fusarium f.sp oxysporum albedinis, causal agent of the vascular wilt (Bayoud) of the date palm, has been achieved. The effect of the aeration of the piles by manual turning has been studied. The maintenance of an adequate humidity of 60%-70%, necessary to the good progress of the composting process, required the contribution of 11.4 L of water/kg of the dried residues. The evolution of the temperatures in the three piles presents the same phases. A latency phase, followed after 2-3 d of composting by a thermophilic phase, which lasts about 24 d, where the temperature remains elevated between 50 and 70 degrees C. Then a cooling phase that takes about 15 d, during which the temperatures fall to values between 25 and 35 degrees C, near room temperature. Fusarium f.sp oxysporum albedinis is eliminated completely during the thermophilic phase of composting, and increasing frequencies of turning accelerate its disappearance to a certain extent. On the other hand, pH remained steady and relatively basic oscillating between 8.2 and 8.7. Ninety percent (90%) of the the date palm residues are composed exclusively of organic matters. The total nitrogen represents only 0.4%. The contribution of manure decreases the ratio of carbon to nitrogen (C/N) from 115 to 48 in the initial mixture. After 80 d of composting and according to the frequency of return up, there is a reduction of the granulometry of the substratum, the C/N ratio (from 29% to 44%), the organic matter (from 15% to 23%), the total volume (from 25% to 35%), and of the dry weight of the swaths (from 16% to 24%). On the other hand there is an increase in total nitrogen rate (from 20% to 40%) and in the mineral matter (from 23% to 35%).     

微生物菌剂对猪粪堆肥中细菌群落结构的影响

以猪粪和小麦秸秆做堆肥试验,处理组添加外源微生物菌剂,利用常规方法对堆肥样品进行理化性状测定,采用高通量测序技术分析堆肥过程中细菌群落特征。理化性状测定结果表明: 添加外源菌剂可延长堆肥高温时间,降低堆肥发酵末期的pH,增加全氮含量,加快C/N的下降。主成分分析表明: 外源菌剂影响堆肥样品细菌群落的稳定性。门分类水平上,厚壁菌门、变形菌门和绿弯菌门的相对丰度在处理组中较高;纲分类水平上,梭状芽孢杆菌纲、α-变形菌纲和γ-变形菌纲在处理组的升温期和高温期相对丰度增加;科分类水平上,小单孢菌科和梭状芽孢杆菌纲的消化链球菌科、梭菌科以及盐厌氧菌科的相对丰度在处理组的升温期和高温期均呈上升趋势。Pearson相关性分析表明,盐胞菌属与外源菌剂呈显著正相关,而氨苄芽孢杆菌属与外源菌剂呈显著负相关。研究表明,猪粪堆肥中添加外源菌剂可使堆肥的理化性质和细菌群落结构均发生显著变化。     

Dehydrogenase activity as a method for monitoring the composting process

Dehydrogenase enzymatic activity was determined to monitor the biological activity in a composting process of organic fraction of municipal solid waste. Dehydrogenase activity is proposed as a method to describe the biological activity of the thermophilic and mesophilic stages of composting. The maximum dehydrogenase activity was detected at the end of the thermophilic stage of composting, with values within 0.5-0.7mgg dry matter(-1)h(-1). Also, dehydrogenase activity can be correlated to static respiration index during the maturation mesophilic stage.     

Effect of low initial C/N ratio on aerobic composting of swine manure with rice straw

Two pilot composting experiments were conducted to investigate the effect of low initial C/N ratio on the composting of swine manure with rice straw by measuring physical and chemical parameters. The results showed that the thermophilic duration of bin 1 and bin 2 was long enough to satisfy the sanitary standard, and swine manure could reach maturity. Bin 1 containing larger amount of swine manure and less amount of rice straw showed a higher nitrogen loss (8%), shorter thermophilic phase, and longer maturity time (about 2 weeks) than bin 2. However, economical analysis showed a lower initial C/N ratio (20) could reduce 172 kg rice straw per ton fresh swine manure than a higher C/N ratio (25), and more swine manure could also be treated. Therefore, a low initial C/N ratio (20) could be suggested in the composting of swine manure with rice straw.     

添加竹炭对猪粪堆肥过程中升温脱水及氮素损失的影响

堆肥是实现畜禽粪便处理及资源化利用的有效途径,但传统堆肥过程存在升温脱水效果不佳及氮素损失的问题.本文利用猪粪进行堆肥试验,探讨了堆肥过程中添加不同比例竹炭对堆肥升温脱水及氮素损失的影响.结果表明: 与不添加竹炭的对照相比,添加竹炭处理可以使堆体升温时间缩短24～48 h,脱水率提高13.6%～21.4%,堆肥高温期持续时间延长216～264 h;添加竹炭处理可以增加堆肥铵态氮、硝态氮及总氮含量,使氮素固定率提高28.3%～65.4%.
     

Comparative effect of live food and manured treatments on water quality and production of ornamental carp, Cyprinus carpio var. koi L., during winter, summer, monsoon and post-monsoon growout experiments in concrete tanks

Four growth trials (each of 11 weeks duration) were conducted during different seasons throughout 1 year, namely, winter, summer, monsoon and post‐monsoon to assess the seasonal influence on growth and production of koi carp, Cyprinus carpio var. koi L. larvae in concrete tanks maintained under different management regimes. Individual weight gain, survival rate, fish deformities and number of marketable fish in each season were compared among four management regimes: (i) carp larvae fed with live zooplankton (LF); (ii) direct fertilization with poultry manure (PM); (iii) direct fertilization with cow dung (CD); and (iv) a control system (C), where a commercial diet containing 32% crude protein was applied. There were three replicates for each treatment. The LF treatment produced significantly higher weight gain, survival rate and number of marketable fish in all seasons (P < 0.05), compared with the other treatments, through maintenance of better water quality and greater abundance of zooplankton in the system. Fish deformities were highest in the C treatment in every season (P < 0.05). Water temperatures averaged 18.6°C (winter), 29.7°C (summer), 28.3°C (monsoon), and 26.5°C in the post‐monsoon trial. Average weight gain of koi carp achieved during the winter trial (2.01 g in C to 4.44 g in LF) was considerably lower than that achieved in the summer, monsoon or post‐monsoon trials. Survival rates of carp ranged from 70.5% (C) to 95.5% (LF) in the winter trial, and were considerably lower than the other seasons. The number of marketable fish was also lowest during the winter trial.     

Improving rock phosphate availability through feeding, mixing and processing with composting manure

The objective of this study was to improve the availability of phosphorus (P) from rock phosphate (RP) through feeding, mixing and composting manure. The experiment was conducted as a 3 x 2 split-plot design. Manure was collected from 12 Boran steers (200+/-4.5 kg live weight) fed a basal diet of Napier grass (Pennisetum purpureum) at 2.5% body weight on a dry matter (DM) basis. The main plot treatments were (i) manure from steers supplemented with 113 g Busumbu rock phosphate (BRP) per day (FBRP), (ii) manure from steers not supplemented with BRP, feces mixed with 113 g BRP per day (MBRP) and (iii) manure from steers not supplemented with BRP and feces not mixed with BRP (CONT). The sub-plots comprised composting the manure either (i) mixed with 440 g of wheat (Triticum aestivum L.) straw per kg fresh feces (WS) or (ii) without straw (WOS). The manure was composted in 200 L plastic bins for 90 days. After 90 days, P availability was evaluated (i) by aerobic laboratory incubation at 25 degrees C for 1, 2, 4, 8, 12, and 16 weeks and (ii) by greenhouse agronomic evaluation study using maize (Zea Mays L.) as the test crop in either a humic Nitosol or an Andosol. In the laboratory incubation study, resin P was higher (p<0.05) for the WS compost than for the WOS compost; values were higher (p<0.05) for the Andosol than for Nitosol and followed the order of FBRP-WS, Andosol>FBRP-WS, Nitosol>MBRP-WS, Andosol>MBRP-WS, Nitosol>FBRP-WOS, Andosol>FBRP-WOS, Nitosol. In the greenhouse evaluation, maize crops in the WS compost had higher (p<0.05) biomass yield than the reference fertilizer, triple super phosphate, (173% versus 196%; Andosol and Nitosol, respectively). The biomass yield and P uptake relative agronomic effectiveness (RAE) for WS compost was also higher (p<0.05) than that of WOS compost (184 versus 3+/-0.8 and 242 versus 162+/-0.2, WS and WOS, biomass yield and P uptake, respectively). Nitosol biomass yield and P uptake RAE were also higher (p<0.05) than for the Andosol (99 versus 88+/-0.8 and 332 versus 72+/-0.2, Nitosol and Andosol, biomass yield and P uptake, respectively). The results show that P-enriched composting in the presence of wheat straw significantly increased P availability and increased plant growth. However, in terms of plant growth, there was no additional benefit of first feeding the RP to steers before composting the manure because most of the RP fed seem to have been utilized by the animal.