The University of Illinos Digester – Principles of Operation

Posted in: Environment by admin on January 1, 1987 | No Comments

All the digestor components and the system operation are presented . However no information are presented on the performances of the digestor. This project has encountered many obstacles as the product and by-products of the anaerobic digestion are aggressive on the equipment also an optimal set up is difficult to find.

Aerobic Manure Treatment – Environmental, Energy and Fertilization Results

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Aeration experiments have been done over 13 years in Norway in order to evaluate the treatment done to swine and dairy manure and the changes in the manure parameters. The motivation for this experimentation was to overcome the known disadvantages associated with liquid manure. Odour and viscosity reductions have been observed as a result to aeration. In order to kill pathogens, parasites and weed seeds, the aeration time as to be long (3 to 4 weeks before spreading) and insulation of the manure storage facility helps reach elevated process temperatures. The efficiency of the aeration treatment on the manure is increased when the temperature reaches 40 to 50 C. The heat produced when the aeration is done in an insulated system can be recovered. Aeration done under the slatted floor in the swine building is not recommended as excessive evaporation occur and some conditions can present a risk for H2S poisoning.

The emissions resulting of such treatment have not been evaluated. Losses in nitrogen can be important with such treatment and the value of the manure in the nutrient cycle is than lowered.

First Trials of Swine manure Odor Control with Depth Aaeration and "Oligolyse"

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Two odor control methods, aerobic deodorizing and oligolyse, were tested for a 120 days period on two different farms having a production of 1500 to 2000 fattening pigs a year. The manure was stored outside the building in a storage basin for the aerobic deodorizing and inside in a pit under the slatted floor for the oligolyse treatment. The aerobic deodorizing consisted of aeration made by 4 aerators (2 submersible pump types and 2 screw types) working on 20 minutes/hour cycles. The oligolyse is a process where an electric potential is created between an copper electrode and a coal one that are placed at a certain distance in the manure. As a result, metallic cations are released from the copper electrode into the manure. Those cations have a sterilizing action on the microorganisms responsible for anaerobical fermentation and malodorous gases production. Results showed that both systems reduced significantly the smell of the manure compared to the untreated on. However, the oligolyse cost 40 to 45% less than the aerobic deodorizing when considering energy cost, and fixed costs.

This experiment was done on only two different storing facilities with no replicate. The results obtained are interesting but more experiments are needed to verify those results. The agronomic value of the manure treated with oligolyse has also to be determined as copper cations are added in the process..

Olfaktometrie Geruchsschwellenbestimmung – Olfactometry Odour Threshold Determination – Sampling

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Guidelines are given for the sampling procedure for odour measurements with an olfactometer considering two sampling methods: the dynamic sampling where partial flow of the sample is continuously taken from the source and directly used to supply the olfactometer on demand and the static sampling where odorous samples are collected in vessels which are later connected to the olfactometer. General considerations are given regarding the sampling such as the possible condensation in the vessel or the instruments used, the interaction with the sample and the condensation surface and reactions among the odorants involved. The dynamic sampling and the static sampling methods are presented with figures showing the basic apparatus. Dynamic odour measurements are recommended for emission source that present stable period of odour concentration emissions, at least during the course of a single measurement. This method also presents advantages because of the short time elapsing between the sampling and the analysis; less chemical reactions in the sample can occur.

The sampling procedures are well presented and explained but not enough specific information is given for the apparatus. This could lead to differences between samplings done over long periods of time and also sampling and analysis done by different laboratory which could use the same sampling methods but no the same apparatus. References to VDI 3881 Part 1.

Recommandations pour la qualite des eaux au Canada

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This guide presents all biological and chemical elements that can be found in the water with their impact on the quality when considering recreational uses, aquatic life or for consumption by animals or humans. Basic information on the processes involved with the contamination of water by these elements, the chemical and bacteriological reactions and the consequence on the environment and health are presented.

The guide consulted was in French but English version are also available. It is a very big guide and covers many possible contaminants that are not a concern in agriculture. However it contains interesting information particularly for nitrogen and bacteria. Most of the elements in the guide present a threat to health at high concentration.

Respiratory Symptoms and Pulmonary Function in Farmers

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Respiratory effects and dust exposure in hog confinement farming

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Olfaktometrie Geruchsschwellenbestimmung – Olfactometry Odour Threshold Determination – Fundamentals

Posted in: Environment by admin on January 1, 1986 | No Comments

Olfactometry is a method of determination of odorants concentration by presentation of odorants to humans and registration of the resulting sensations; the human sense of smell being used as a detector. This method allow determination of the human smell power for known odorant concentrations and also the determination of unknown odorant concentrations by mean of human smell sense. Guidelines are given for the determination of odour threshold and the derived quantity of odorant concentration. The anatomical/physiological and psycho-physiological fundamentals of the odour phenomenon are presented. The terms used in olfactometry and their definitions are given. The measuring procedures are explained in a general matter covering the instruments, the sampling, the presentation of concentrations, the questioning technique, the panel, and the boundary conditions. The equations for the calculation of odorant concentration are given.

This publication gives a very good definition of the olfactometry and the procedures to realize odour threshold determination. However, the information presented is general and has to be considered as guidelines, not enough details are given to realize standard tests.

Olfaktometrie Geruchsschwellenbestimmung – Olfactometry Odour Threshold Determination – Olfactometers with gas jet dilution

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Guidelines are given for the use of olfactometers for dynamic dilution . The olfactometer uses a gas jet pump which thoroughly mixes the metered odorous flow and the constant neutral air flow. The mix is presented as concentration step for odour to panelist through a nose mask for evaluation. The threshold evaluation requires yes/no decision confirming the detection of odours. Two instruments are presented (Olfactometers Model 1158 and TO 4) with their apparatus diagram representing the components and the air and odour flows. For the first model 1158, an operator does all the procedures so the panelists only have to test the mixed samples. For the TO 4 which is a portable measuring device, the panelist is also the operator. Panelists selection has to be done in order to make sure that the persons’ sense of smell is normal and that they can follow the operator’s instructions. External disturbance should be avoided when the panelists are making the measurements as odours, noise, vibrations can affect the concentration and the odour sensation. Also verifications should be made to assure that the air mix reaching the nose mask does not contain toxic gases. The dilution system should be calibrated prior to the first use and at least annually using suitable test gases (propane or n-butane in test gas bottles) and gas analyzers. Measuring procedures are also provided. The instruments presented can be used in odour intensity determination and to determine the hedonic tone of an odour. A minimum dilution concentration has to be considered for each instrument considering their technical limits. For the instruments presented, determination of odorant concentration below 15 OU/m3 should not be allowed.

Detailed information is given for the dynamic dilution tests. However, this information is not precise enough regarding the apparatus and technical specifications. References to VDI 3881 Part 1 and 2.

Nitrogen Losses from Swine Housings

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