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The Mini-Earth facility and present status of habitation experiment program.

The history of construction of the CEEF (the Mini-Earth), the configuration and scale of the CEEF are initially described. The effective usable areas in plant cultivation and animal holding and habitation modules and the accommodation equipment installed in each module are also explained. Mechanisms of the material circulation systems belonging to each module and subsystems in each material circulation system are introduced. Finally the results of pre-habitation experiments conducted until the year 2004 for clarifying the requirements in order to promote final closed habitation experiments are shown.

Agriculture↗

Simulation model for the closed plant experiment facility of CEEF.

The Closed Ecology Experiment Facilities (CEEF) is a testbed for Controlled Ecological Life Support Systems (CELSS) investigations. CEEF including the physico-chemical material regenerative system has been constructed for the experiments of material circulation among plants, breeding animals and crew of CEEF. Because CEEF is a complex system, an appropriate schedule for the operation must be prepared in advance. The CEEF behavioral Prediction System, CPS, that will help to confirm the operation schedule, is under development. CPS will simulate CEEFs behavior with data (conditions of equipments, quantity of materials in tanks, etc.) of CEEF and an operation schedule that will be made by the operation team everyday, before the schedule will be carried out. The result of the simulation will show whether the operation schedule is appropriate or not. In order to realize CPS, models of the simulation program that is installed in CPS must mirror the real facilities of CEEF. For the first step of development, a flexible algorithm of the simulation program was investigated. The next step was development of a replicate simulation model of the material circulation system for the Closed Plant Experiment Facility (CPEF) that is a part of CEEF. All the parts of a real material circulation system for CPEF are connected together and work as a complex mechanism. In the simulation model, the system was separated into 38 units according to its operational segmentation. In order to develop each model for its corresponding unit, specifications for the model were fixed based on the specifications of the real part. These models were put into a simulation model for the system.

Agriculture↗

Characterisation of the organic matter pool in manures.

In this research, different types of animal manure were evaluated with respect to organic matter (OM), total organic carbon (C(ot)), total N (N(t)), C(ot)/N(t) ratio, water-soluble organic carbon (C(w)), organic N (N(org)), carbohydrates, C(w)/N(org) ratio, humic acid-like carbon (C(ha)), fulvic acid-like carbon (C(fa)), humification index ((C(ha)/C(ot))x100) (HI) and the C(ha)/C(fa) and NH(4)(+)-N/NO(3)(-)-N ratios. In comparison with the limits set by the Spanish legislation for organic fertilisers, most of the manures had high OM contents, moderate N(org) concentrations (except in the case of the chicken and pig manures where this parameter was high) and C(ot)/N(t) ratios above the value stated in the legislation. The study of the different fractions of organic matter showed that the horse, pig and rabbit manures had the greatest content of C(ot). However, the fraction of easily-biodegradable organic compounds (C(w)) was significantly higher in the horse, goat and chicken manures. The study also showed that, in most cases, the percentage of fulvic acid-like C was greater than that of the humic acid-like C, indicating that the organic matter of these wastes is not completely humified. Values of HI ((C(ha)/C(ot))x100) and C(ha)/C(fa) ratio in the studied manures were not significantly different. Regarding the parameters related to the organic matter stability such as C(w), carbohydrates and the C(ot)/N(t), C(w)/N(org) and NH(4)(+)-N/NO(3)(-)-N ratios, it has been determined that the organic matter of these materials was not completely stabilised. The heterogeneity in OM composition of the studied manures did not allow the formulation of simple equations for evaluation of the composition of these wastes from easily-determined parameters.

Animals↗

A respirometric method for characterising the organic composition and biodegradation kinetics and the temperature influence on the biodegradation kinetics, for a mixture of sludge and bulking agent to be co-composted.

A respirometric method was set up to study kinetics of biological reactions involved in the treatment of organic wastes-sludge mixed with pine barks--by composting. Oxygen consumption rates of this type of mixture were monitored during 10-20 days, using a 10 l respirometric cell kept at constant temperature and moisture. Oxygen consumption kinetics were modelled and organic matter composition was characterised as biomass, easily-biodegradable, slowly-biodegradable and non-biodegradable organic matter. The influence of temperature on kinetics was tested. Results show that this respirometric method is a useful tool for the characterisation of solid organic matter biodegradability and for the modelling of the biological kinetics of the composting process.

Biodegradation, Environmental↗

Evolution of temperature and chemical parameters during composting of the pig slurry solid fraction amended with natural zeolite.

A 3-month experiment was conducted at a 300 kg scale to observe decomposition processes in pig slurry solids amended with two different doses of natural Slovak zeolite-clinoptilolite (substrates S1 and S2, 1% and 2% of zeolite by weight, respectively) in comparison with the control (unamended solids). The experimental and control substrates were stored outdoors in sheltered static piles at ambient temperatures ranging from 8.0 to 34.7 degrees C. The solid fraction (SF) of pig slurry was obtained by separation on vibration sieves prior to slurry treatment with activated sludge. The initial water content of the SF was 77.1% and no water was added to the piles during the storage. The temperature in the core of the piles was recorded throughout the experiment. By day 3 and 5 of storage (1% and 2% zeolite, resp.), the temperature in the substrates S1 and S2 exceeded 55 degrees C and remained above this level for 15 days while the highest temperature recorded in the control during the experiment was 29.8 degrees C. Samples from the core of the piles were taken periodically to determine pH, dry matter at 105 degrees C (DM), ash (550 degrees C/4 h), ammonia nitrogen (N-NH(4)(+)), nitrate nitrogen (N-NO(3)(-)), total nitrogen (N(t)), total phosphorus (P(t)); total organic carbon (TOC) was computed. The results showed that pH levels in S1 and S2 remained below that in the control for most of the thermophilic stage. This may be related to water-soluble ammonia and the affinity of zeolites to ammonium ions. A significant decrease in the level of ammonia nitrogen in water extracts from S1 and S2 was observed between days 5 and 35 in comparison with the control. The values of ash also differed and corresponded to the intensity of the decomposition processes in the respective substrates.

Ammonia↗

The issues of energy and carbon cycle: new perspectives for assessing the environmental impact of animal waste utilization.

This paper focuses on the benefits of an efficient use of animal waste from the standpoint of curbing the rise of anthropogenic carbon dioxide (CO(2)) in the atmosphere. An effective use of animal waste resources might provide a partial, but still important, contribution in reducing net CO(2) emissions. In particular: the fulfillment of nutrient requirements of crop plants growing in non-limiting conditions and thus sequestering CO(2) at their potential level; the chance of diminishing the use of fossil energy, and related CO(2) emissions, required for manufacturing industrial fertilizers; the possibility of enhancing carbon sequestration in agricultural soils by the application of farmyard manure. The future success of agriculture in providing these ecosystem services can only be achieved with a changed social awareness of the links between sustainable land use and global environmental change.

Agriculture↗

Thermophilic aeration of cattle slurry with whey and/or jam wastes.

Thermophilic aeration of cattle slurry and food industrial by-products was studied with the aim to improve hygienic qualities of the slurry so that it could be used as a safe fertiliser for berries to be eaten raw. We also wanted to study if the process would be energetically favourable in an arctic climate. Cattle slurry alone or with whey and/or jam waste was treated. The tests were done in a well heat-insulated reactor with a 10 m(3) volume. Temperature increases up to over 70 degrees C could be recorded in 19 days even though some processes were carried out in winter time when the ambient air temperature was less than 0 degrees C. The heat energy formed was higher than the electrical energy needed to carry out the aeration. The hygienic qualities of the aerated product were good with only minor nitrogen losses. The end product could be useful as a fertiliser and soil improving compound to increase the organic matter content of agricultural soil. Cattle slurry alone was well suited as the raw material if attaining a high temperature was the main goal. A part of slurry could be replaced with food-industrial side products. Whey waste suited better for co-composting than jam waste but the mixture of whey, jam waste, and slurry was optimal for composting.

Air↗

Growth of Vetiveria zizanioides and Phragmities australis on Pb/Zn and Cu mine tailings amended with manure compost and sewage sludge: a greenhouse study.

The Lechang lead/zinc (Pb/Zn) mine and Dabao Shan copper (Cu) mine are located at the north of Guangdong Province in southern China. The residual tailings were permanently stored in tailings ponds which required revegetation to reduce their impact on the environment. A greenhouse study was conducted to evaluate the feasibility of using Vetiveria zizanioides (vetiver) and Phragmities australis (common reed) for the reclamation of Pb/Zn and Cu mine tailings and to evaluate the effects of organic amendments using manure compost (11.00, 22.03, 44.05 and 88.10 t/ha) and sewages sludge (11.00, 22.03, 44.05 and 88.10 t/ha) on the revegetation of these tailings. The results revealed that the applications of manure compost or sewage sludge not only increased N, P and K concentrations, but also decreased DTPA-extractable Pb and Zn contents in Pb/Zn tailings and DTPA-extractable Cu contents in Cu tailings. For Pb/Zn mine tailings, application of sewage sludge increased the yields of both species (highest yield at 44.05 t/ha), but not manure compost. For Cu mine tailings, application of manure compost (highest yield for both species at 44.05 and 22.03 t/ha for vetiver and common reed accordingly) or sewage sludge (highest yield at 22.03 and 44.05 t/ha for vetiver and common reed accordingly) increased the yield of both species. In general, vetiver achieved a higher yield when compared with common reed, under the same treatment. Plant tissue analysis showed that application of manure compost and sewage sludge could significantly reduce Pb uptake and accumulation, but not Cu in both vetiver and common reed.

Chrysopogon↗

Dewatering of phosphorus extracted from liquid swine waste.

Phosphorus (P) recovery from liquid swine manure is an attractive technology when on-farm application of liquid swine manure is not an option. We developed a technology that enables separation of this P, but its high moisture content makes transportation difficult. In this work, we investigated dewatering procedures to concentrate the P product. Sludge rich in calcium phosphate (> 20% P2O5) was obtained using a field prototype, and it was further dewatered using a combination of polymer treatment and filter bags. Anionic polyacrylamide polymer treatment (> or = 20 mg/L) was effective to flocculate the P-rich sludge, which enhanced filtration and dewatering. Without polymer, filtration was incomplete due to clogging of filters. Non-woven polypropylene and monofilament filter bag fabrics with mesh size < or = 200 microm retained > 99% of suspended solids and total P. Solids content dramatically increased from about 1.5% to > 90%. These dewatered solids can be transported more economically off the farm for use as a valuable fertilizer material.

Acrylic Resins↗

Vermicomposting of different types of waste using Eisenia foetida: a comparative study.

A study (100 days duration) was conducted to evaluate the efficiency of an exotic earthworm species (epigeic-Eisenia foetida) for decomposition of different types of organic substrates (kitchen waste, agro-residues, institutional and industrial wastes including textile industry sludge and fibres) into valuable vermicompost. The percentage of, nitrogen, phosphorous and potassium in vermicompost was found to increase while pH and total organic carbon declined as a function of the vermicomposting period. 4.4-5.8-fold increases in TKN was observed in different feed mixtures at the end of vermicomposting period. The increase in TKN for different feed substrates was found in the order: textile sludge>textile fibre=institutional waste>agro-residues>kitchen waste. Available Phosphorus increased 1.4 to 6.5-fold in different feed mixtures in comparison to control. Reduction in TOC was highest in agro-residues (3-fold) followed by kitchen waste (2.2-fold), institutional waste (1.7-fold) and textile industrial wastes (sludge, 1.5-fold and fibre, 1.68-fold) in earthworm-inoculated pots than control. The data reveals that vermicomposting (using E. foetida) is a suitable technology for the decomposition of different types of organic wastes (domestic as well as industrial) into value-added material.

Animals↗

Effect of pH on nickel biosorption by aerobic granular sludge.

The Ni2+ biosorption by aerobic granular sludge was studied at various initial pH values of 2-7. Results showed that the initial pH would play an important role in the Ni2+ removal by aerobic granules and affected the zeta potential of aerobic granules. A thermodynamic equilibrium isotherm previously developed can fit the experimental data very well at all studied pH values. The close relationship between the zeta potential and Ni2+ biosorption capacity of aerobic granules showed the electrostatic attraction between the aerobic granules and Ni2+ ions. It was also found that some light metals, such as K+, Mg2+ and Ca2+ would be released into the bulk solution during the Ni2+ uptake onto the aerobic granules, which in turn indicated that ion-exchange was one of the Ni2+ biosorption mechanisms.

Adsorption↗

Determination and comparison of sludge reduction rates caused by microfaunas' predation.

Using micorfauna to reduce excess sludge is a potentially effective ecological technology and scaling the rate of sludge reduction rate is the first step. A method to scale the rate of sludge reduction caused by microfauna was proposed, and comparison of sludge reduction rates induced by four microfaunas was carried out. The principle of this method is based on the change of carbon forms. The rate of sludge reduction was correlated with the rate at which solids were changed into liquid and gas. Four microfaunas, including Aeolosoma hemprichi, Daphnia magna, Tubifex tubifex and Physa acuta, were cultured with sterilized sludge in a covered sterilized bottle and were then isolated from the atmosphere above the liquid phase. The rates of sludge reduction using the four microfaunas were 0.8, 0.18, 0.54 and 0.1 mg-sludge/(mg-Microfauna d), respectively, changing with the microfaunas' phylum or class and body size. Based on the change of carbon (C) forms, the proposed method produced accurate results similar to those produced using the direct measuring method.

Animals↗

Effect of microwave irradiated Methanosarcina barkeri DSM-804 on biomethanation.

Methanosarcina barkeri DSM-804, a methanogenic bacterium, when exposed to microwave radiation of frequencies ranging from 13.5 to 36.5 GHz, showed faster growth in comparison to the unirradiated bacterial culture. Methane concentration in the biogas generated from the irradiated culture was higher than that from unirradiated one, which was to 76.3% on the 15th day of incubation at a microwave radiation frequency of 31.5 GHz, 10 dbm power when irradiated for 2 h. Microscopic study of pure culture revealed that the cells of M. barkeri were more in number and their cell diameter was enlarged by 20%. Inoculation of the culture in a biogas digester containing a combination of jute waste and vegetable market waste as substrate increased the efficacy of biomethanation and reduced its lag phase significantly.

Biotechnology↗

Effect of addition of organic waste on reduction of Escherichia coli during cattle feces composting under high-moisture condition.

To ensure Escherichia coli reduction during cattle feces composting, co-composting with a variety of organic wastes was examined. A mixture of dairy cattle feces and shredded rice straw (control) was blended with organic wastes (tofu residue, rice bran, rapeseed meal, dried chicken feces, raw chicken feces, or garbage), and composted using a bench-scale composter under the high-moisture condition (78%). The addition of organic waste except chicken feces brought about maximum temperatures of more than 55 degrees C and significantly reduced the number of E. coli from 10(6) to below 10(2)CFU/g-wet after seven days composting, while in the control treatment, E. coli survived at the same level as that of raw feces. Enhancements of the thermophilic phase and E. coli reduction were related to the initial amount of easily digestible carbon in mass determined as BOD. BOD value more than 166.2 mg O2/DMg brought about significant E. coli reduction.

Animals↗

Composting of high moisture content swine manure with corncob in a pilot-scale aerated static bin system.

Pilot composting experiments of swine manure with corncob were conducted to evaluate the performance of the aerated static bin composting system. Effects of temperature control (60 and 70 degrees C) and moisture content (70% and 80%) were monitored on the composting by measuring physical and chemical indexes. The results showed that (1) the composting system could destroy pathogens, converted nitrogen from unstable ammonia to stable organic forms, and reduced the volume of waste; (2) significant difference of NH(4)(+)-N (P(12) = 0.074), and (NO(3)(-) + NO(2)(-))-N (P(12) = 0.085) was found between the temperature control treatments; (3) anaerobic reaction in the treatment with 80% moisture content resulted in significant difference of pH (P(23) = 0.006), total organic matter (P(23) = 0.003), and germination index (P(23) = 0.040) between 70% and 80%. Therefore, the optimum initial moisture content was less than 80% with the composting of swine manure and corncob by using the composting system.

Air↗

Mercury(II) removal from aqueous solutions by nonviable Bacillus sp. from a tropical estuary.

Use of microorganisms for removing mercury is an effective technology for the treatment of industrial wastewaters and can become an effective tool for the remediation of man-impacted coastal ecosystems with this metal. Nonviable biomass of an estuarine Bacillus sp. was employed for adsorbing Hg(II) ions from aqueous solutions at six different concentrations. It was observed that 0.2 g dry weight of nonviable biomass was found to remove from 0.023 mg (at 0.25 mg L(-1) of Hg(II)) to 0.681 mg (at 10.0 mg L(-1) of Hg(II)). Most of the mercury adsorption occurred during the first 20 min. It was found that changes in pH have a significant effect on the metal adsorption capacity of the bacteria, with the optimal pH value between 4.5 and 6.0 at 25 degrees C when solutions with 1.0, 5.0 and 10.0 mg L(-1) of Hg(II) were used.

Bacillus↗

Lactic acid fermentation of food waste for swine feed.

This study was conducted to determine the effects of lactic acid bacteria (LAB, Lactobacillus salivarius) inoculation on the microbial, physical and chemical properties of food waste mixture (FWM) stored at ambient temperature (25 degrees C) for 10 and 30 days. A complete pig diet including restaurant food waste, bakery by-product, barley and wheat bran, and broiler poultry litter was amended with LAB at the levels of 0.1%, 0.2%, 0.5% and 1.0% and fermented anaerobically. These treatments were compared with intact FWM before storage and non-anaerobically stored FWM. Non-anaerobic storage of FWM showed microbial putrefaction with the loss (P < 0.05) of water and water soluble carbohydrate (WSC) and increases (P < 0.005) in protein and fiber. Anaerobic fermentation of FWM with or without LAB seemed effective in both 10- and 30-day-storage. The addition of LAB inoculants to FWM showed a linear trend (P < 0.05) toward an increase in the number of total and lactic acid bacteria and toward the nutritional improvement with WSC increased and fiber decreased. Long-term (30 days) storage resulted in consistent reduction (P < 0.05) in numbers of total and lactic acid bacteria and pH and showed little change in chemical components, compared with short-term (10 days) storage. On the basis of these results, LAB inoculation improved fermentative characteristics of FWM. Among anaerobic treatments, further WSC increase and NDF reduction did not occur (P > 0.05) when LAB-added levels were over 0.2%. Based on these observations the optimum level of LAB addition to FWM was 0.2%.

Anaerobiosis↗