**2.3 Statistical analysis**

The physical and chemical properties (pH, DM, IM, OM, NH4 +, Nt,) of solid animal wastes, as well as the number of demaged eggs were expressed as mean values ± standard deviation ( x ±SD).

Significance of differences between experimental and control groups of parasites were determined using Student t-test, ANOVA and Dunnet Multiple Comparison test at the levels of significance 0.05; 0.01 and 0.001 (Statistica 6.0).

### **Results**

52 Management of Organic Waste

Picture 1. Polyurethane carrier with adhered *A. suum* eggs

Picture 2. Perforated plastic nets with the carriers

The samples were examined for the pH (1:10 water extract) using a pH electrode (HACH Company, Loveland, Colorado, USA). Dry matter (drying at 105°C to a constant weight), residum-on-ignition (550°C for 4 h), and water soluble ammonium nitrogen (NH4+) by titration (Mulvaney, 1996). Soluble and insoluble substances were determined by evaporation of the known amount of homogeneous sample filtrate on a water bath after

#### **a) Anaerobic stabilisation of liquid animal wastes**

Investigations were carried out under operating conditions of the large-capacity pig farm in Slovak Republic (Picture 3). Technological equipment for anaerobic treatment of pig slurry on the principle of methanogenesis with the production of biogas was built up on the farm (Picture 4). Pig slurry was treated in the bioreactor (2 500 m3) manufactured by Mostáreň Brezno under the agreement with the firm BAUER Voitsberg. The stirring of the substrate in this reactor was done at the expense of energy of the generated biogas. Mean daily input of raw pig slurry in bioreactor of biogas plant varied between 78 and 144 m3. The volume of digested slurry after methanogenesis was equal to that of the input. Two lagoons were the part of the biogas plant. The volume of larger lagoon is 20 000 m3 (Picture 5) and that of smaller lagoon is 5 000 m3. Both lagoons serve as reservoirs of digested slurry. Liquid fraction from the smaller lagoon was carried away and spread on fields. The presence and survival of parasite eggs were studied in the larger lagoon. Samples were taken from raw slurry collecting basin before the inlet in to bioreactor (input samples), from outlet of digested slurry after methanogenesis in bioreactor (output samples), from supernatant (liquid fraction) and from lagoon sludge (solid fraction - sediment). The slurry samples for parasitological and physical and chemical examination were collected monthly during 29 month.

Slurry from the pig farm stored in the collecting basin showed a considerable variability during the period of study (Table 1). Compared with mean pH value of 7.12 ± 0.26, pH raw slurry in the month 11, 17 and 21 was lower, ranging between 6.61 and 6.95. The most conspicuous differences were recorded in DM content, which is most likely associated with the amount of process water use. The DM content in raw slurry determined during the period studied ranged from 0.81 % to 5.30 %. The amount of NH4 + in raw slurry was between 821 mg.l-1 and 1 774 mg.l-1. Chemical oxygen demand (COD) for that period varied from 2 000 mg.l-1 to 22 530 mg.l-1. The mean contents of Nt, in slurry was 1 445 ± 420 mg.l-1.

The Sanitation of Animal Waste Using Anaerobic Stabilization 55

Like raw pig slurry also slurry stabilised by anaerobic process showed variability of its physical-chemical parameters on its out flow from bioreactor (Table 2). Conspicuous differences were observed mainly in the dry mater content of anaerobically stabilized slurry.

Picture 5. Large lagoon for storing digested pig slurry

Picture 6. Embryonated *A. suum* eggs

Picture 3. Large-capacity pig farm

Picture 4. Bioreactors of biogas plant

Picture 3. Large-capacity pig farm

Picture 4. Bioreactors of biogas plant

Picture 5. Large lagoon for storing digested pig slurry

Picture 6. Embryonated *A. suum* eggs

Like raw pig slurry also slurry stabilised by anaerobic process showed variability of its physical-chemical parameters on its out flow from bioreactor (Table 2). Conspicuous differences were observed mainly in the dry mater content of anaerobically stabilized slurry.

The Sanitation of Animal Waste Using Anaerobic Stabilization 57

Anaerobically stabilized slurry was pumped from bioreactors into slurry ground lagoon for further storage. A long-term storage of digested slurry in lagoon is the most effective way of treatment resulting in a elimination of helminth eggs (Schwartzbrod et al., 1989). At the same time there is an increase in biogenic elements, especially of nitrogen and phophorus which are transformed into the forms acceptable by plants. Results of the chemical analysis of liquid fraction (supernatant) are presented in Table 3 and those of solid fraction (sludge) of lagoon in Table 4. pH of supernatant has not changed much over the period studied. Mean pH was 8.20 ± 0.11 %. Sediment pH decreased during the first period of the study (month 0-6) and than again increased. Ammonia content was about equal in both the fraction. The highest content of NH4+ was detected in spring month with its decrease observed in the course of study. Nt contained by supernatant samples varied between 882 mg.l-1 to 2 283 mg.l-1 (Table 3) and in sediment between 3 571 mg.l-1 to 57 831 mg.l-1 (Table 4).

Sediment contained more DM and Nt than supernatant (Tables 3, 4).

**IM (%)**

+ - ammonium ions, Nt - total nitrogen, - - not examined)

*A. sum* eggs and *Oesophagostomum* sp. eggs were rarely detected in slurry on the input and also on the output of bioreactor (Table 5). Similar results of helminths eggs occurrence in anaerobic slurry treatment were also presented by Juriš et al. (1996), No helminth eggs were found in the supernatant of digested slurry from the lagoon. *A. suum* eggs were found in

High percentage of devitalised unembryonated *A. suum* eggs (47.46 ± 0.78 %) stored 11 months (from May – month 13 to March - month 23) in a ground slurry lagoon points to the impact of high concentration of NH4+ (max. 5 358 mg.l-1 in sediment compared to 1 863 mg.l-1 in supernatant), which are releasing during a period of time from an open area of the

**OM (%)** 

8.30 4 500 0.50 61.06 38.94 4 416 581 1 737 1 910 8.20 4 000 0.50 70.39 29.61 4 808 174 1 307 1 428 8.17 2 002 0.68 57.58 42.42 6 579 239 1 345 1 569 8.34 3 500 0.66 57.75 42.25 5 340 1 272 1 111 1 214 8.10 7 600 0.93 56.04 43.96 6 085 3 177 1 408 1 662 8.08 6 552 0.87 52.76 47.24 3 600 5 255 1 135 1 172 8.29 1 530 0.71 57.59 42.41 2 748 4 337 1 107 1 223 8.21 7 059 0.70 55.53 44.47 5 954 1 083 1 863 2 283 8.07 818 1.68 46.60 53.40 5 588 11 217 1 569 1 569 8.28 1 904 0.66 54.83 45.17 5 325 1 284 1 331 1 317 8.21 5 385 0.63 56.38 43.62 4 483 1 806 896 882 8.29 8 605 0.60 54.27 45.73 3 501 2 524 616 1 415 8.32 3 333 0.35 71.43 28.57 2 128 1 372 672 1 016 7.95 5 000 0.75 45.33 54.67 3 000 4 500 862 1 031 Table 3. Physico-chemical properties of supernatant from stabilized pig slurry stored in lagoon (COD – chemical oxygen demand, DM - dry matter, IM - inorganic mater, OM - organic

**Soluble substances (mg.l-1)** 

**Insoluble substances (mg.l-1)** 

**NH4+ (mg.l-1)** 

**Nt (mg.l-1)** 

**DM (%)**

**Storage** 

matter; NH4

sediment (Table 5).

**(month) pH COD** 

**(mg.l-1)** 

This is caused by the projected input, reckoning on the 5 % of dry matter in raw pig slurry, but the mean dry matter content in raw slurry supplied to bioreactor was 1.96 % and therefor poultry excrements had to be regularly added (average DM content 22.27 %) to pig slurry prior to its supply into bioreactor. Stabilized slurry outlet of bioreactor contained as much as 3.23 ± 2.54 % DM on the average. Anaerobic digestion increased slurry pH which was ranging from 7.37 to 8.50. Compared with untreated slurry, anaerobic stabilization increased the content NH4 + to 7.80 ± 0.29 mg.l-1 on average. Concentration of Nt was increased twice.


Table 1. Physico-chemical properties of raw pig slurry (input sample of bioreactor) (COD – chemical oxygen demand, DM - dry matter, IM - inorganic mater, OM - organic matter; NH4+ - ammonium ions, Nt - total nitrogen, - - not examined)


Table 2. Physico-chemical properties of digested pig slurry (output sample of bioreactor) (COD – chemical oxygen demand, DM - dry matter, IM - inorganic mater, OM - organic matter; NH4 + - ammonium ions, Nt - total nitrogen, - - not examined)

This is caused by the projected input, reckoning on the 5 % of dry matter in raw pig slurry, but the mean dry matter content in raw slurry supplied to bioreactor was 1.96 % and therefor poultry excrements had to be regularly added (average DM content 22.27 %) to pig slurry prior to its supply into bioreactor. Stabilized slurry outlet of bioreactor contained as much as 3.23 ± 2.54 % DM on the average. Anaerobic digestion increased slurry pH which was ranging from 7.37 to 8.50. Compared with untreated slurry, anaerobic stabilization increased the

+ to 7.80 ± 0.29 mg.l-1 on average. Concentration of Nt was increased twice.

7.44 14 833 2.75 31.87 68.13 11 263 16 264 1 774 2 419 7.34 2 000 0.84 51.42 48.58 5 836 2 612 1 186 1 401 7.17 9 297 0.95 43.04 56.96 4 561 4 897 821 1 195 7.03 13 500 1.14 57.71 42.29 7 757 3 641 1 202 1 485 7.00 20 900 1.57 38.74 61.26 11 095 4 572 1 078 1 363 7.35 14 824 0.81 45.71 54.29 4 895 3 178 1 037 1 191 7.36 13 333 2.52 17.36 52.64 5 366 19 844 1 247 1 429 6.61 21 795 5.30 33.02 66.98 - - 1 695 1 089 6.95 12 750 0.95 30.53 69.47 1 000 8 500 1 478 1 010 6.95 22 530 2.80 19.97 80.03 5 870 22 130 1 358 1 872

Table 1. Physico-chemical properties of raw pig slurry (input sample of bioreactor) (COD – chemical oxygen demand, DM - dry matter, IM - inorganic mater, OM - organic matter;

> **OM (%)**

Table 2. Physico-chemical properties of digested pig slurry (output sample of bioreactor) (COD – chemical oxygen demand, DM - dry matter, IM - inorganic mater, OM - organic

+ - ammonium ions, Nt - total nitrogen, - - not examined)

8.50 36 333 - - - - - 2 633 6 320 7.74 10 500 0.81 56.54 43.46 4 739 3 401 2 204 2 605 7.63 17 820 1.24 48.50 51.50 6 134 6 226 2 157 2 699 7.80 8 500 1.96 59.69 40.31 6 192 13 456 2 045 2 549 7.69 17 100 3.16 41.81 58.19 5 965 5 658 1 933 3 138 7.77 6 092 4.48 42.06 57.94 3 225 41 603 1 898 1 982 7.92 2 186 2.91 42.87 57.13 3 555 25 518 2 437 3 516 7.88 4 872 0.50 70.00 30.00 - - 2 171 1 530 7.37 7 750 6.45 39.84 60.16 1389 63 111 2 248 1 936 7.66 42 169 7.85 33.81 66.19 1 333 77 167 2 655 3 399

**Soluble substances (mg.l-1)** 

**Soluble substances (mg.l-1)** 

**Insoluble substances (mg.l-1)** 

**Insoluble substances (mg.l-1)** 

**NH4+ (mg.l-1)** 

**Nt (mg.l-1)** 

**NH4+ (mg.l-1)** 

**Nt (mg.l-1)** 

**OM (%)**

content NH4

**Storage** 

**Storage** 

matter; NH4

**(month) pH COD** 

**(mg.l-1)**

**(month) pH COD** 

**(mg.l-1)**

**DM (%)** 

NH4+ - ammonium ions, Nt - total nitrogen, - - not examined)

**DM (%)**

**IM (%)** 

**IM (%)**  Anaerobically stabilized slurry was pumped from bioreactors into slurry ground lagoon for further storage. A long-term storage of digested slurry in lagoon is the most effective way of treatment resulting in a elimination of helminth eggs (Schwartzbrod et al., 1989). At the same time there is an increase in biogenic elements, especially of nitrogen and phophorus which are transformed into the forms acceptable by plants. Results of the chemical analysis of liquid fraction (supernatant) are presented in Table 3 and those of solid fraction (sludge) of lagoon in Table 4. pH of supernatant has not changed much over the period studied. Mean pH was 8.20 ± 0.11 %. Sediment pH decreased during the first period of the study (month 0-6) and than again increased. Ammonia content was about equal in both the fraction. The highest content of NH4+ was detected in spring month with its decrease observed in the course of study. Nt contained by supernatant samples varied between 882 mg.l-1 to 2 283 mg.l-1 (Table 3) and in sediment between 3 571 mg.l-1 to 57 831 mg.l-1 (Table 4). Sediment contained more DM and Nt than supernatant (Tables 3, 4).


Table 3. Physico-chemical properties of supernatant from stabilized pig slurry stored in lagoon (COD – chemical oxygen demand, DM - dry matter, IM - inorganic mater, OM - organic matter; NH4 + - ammonium ions, Nt - total nitrogen, - - not examined)

*A. sum* eggs and *Oesophagostomum* sp. eggs were rarely detected in slurry on the input and also on the output of bioreactor (Table 5). Similar results of helminths eggs occurrence in anaerobic slurry treatment were also presented by Juriš et al. (1996), No helminth eggs were found in the supernatant of digested slurry from the lagoon. *A. suum* eggs were found in sediment (Table 5).

High percentage of devitalised unembryonated *A. suum* eggs (47.46 ± 0.78 %) stored 11 months (from May – month 13 to March - month 23) in a ground slurry lagoon points to the impact of high concentration of NH4+ (max. 5 358 mg.l-1 in sediment compared to 1 863 mg.l-1 in supernatant), which are releasing during a period of time from an open area of the

The Sanitation of Animal Waste Using Anaerobic Stabilization 59

**Storage (month) Damaged A. suum eggs (** <sup>x</sup> **%±SD)** 

Table 6. Damage of *A. suum* eggs during long term storage of anaerobic stabilized pig slurry

The effect of anaerobic stabilisation of solid animal wastes (manure, dog excrements) with or without addition of lime on the survival of parasitic germs were studied under laboratory conditions. Two types of lime was used in the experiment: 1. quality dust lime and 2. dust rejects from lime production caught on the electrostatic precipitator. General characteristics

**CaO + MgO** min. 95.0 % min. 82.0 % **MgO** max. 5.0 % max. 3.5 % **CO2** max. 2.5 % max. 11.0 %

**Granularity** 0-0.2 mm 0-1.0 mm

Pig manure (M) and dog excrements mixed with hay in the ratio of 1:5 (D) were used in the experiment. Organic wastes were mixed with tested lime in a different concentration and periodically stirred. The following variations were investigated in comparison to untreated

Samples for parasitological and physical and chemical examinations were collected after 0, 1, 3, 8, 14, 36 (UM, ML20 and M20) and after 0, 1, 2, 3, 7, 8, 9, 10, 14, 73 (UD, D20, D70) days of exposure. Three samples were taken and analysed at each of the given sampling intervals. The physical and chemical properties of treated manure and dog excrements are given in Tables 8 - 13. Comparison of the changes in The physical and chemical properties of organic material during anaerobic stabilisation with or withou dust rejects is given in Fig. 1 – 5.

a. manure mixed with quality dust lime in a concentration of 20 g.kg-1 (ML20) b. manure mixed with dust rejects in a concentration of 20 g.kg-1 (M20)

c. dog droppings mixed with dust rejects in a concentration of 20 g.kg-1 (D20), d. dog droppings mixed with dust rejects in a concentration of 70 g.kg-1 (D70).

in lagoon

**b) Anaerobic stabilisation of solid animal wastes** 

Table 7. Physico-chemical properties of the tested types of lime

(control) manure (CM) and untreated dog droppings (CD):

of tested lime are given in Table 7.

**May (13)** 16.23 ± 3.22 14.80 ± 2.43 **June (14)** 38.27 ± 2.51 15.79 ± 2.44 **September (17)** 40.37 ± 2.94 18.23 ± 1.22 **March (23)** 47.46 ± 0.78 19.60 ± 1.80

**Lagoon Control** 

**Quality dust lime Dust rejects** 

ground lagoon, and nitrogen (max. 9 854 mg.l-1 in sediment compared to 2 283 mg.l-1 in supernatant) on devitalization of developmental stages of endoparasites. The number of devitalised *A. suum* eggs increased towards to the bottom of lagoon. In the control groups, only 19.60 ± 1.80 % of *A. suum* eggs were devitalized (Table 6).


Table 4. Physico-chemical properties of sediment from stabilized pig sllury stored in lagoon (COD – chemical oxygen demand, DM - dry matter, IM - inorganic mater, OM - organic matter; NH4 + - ammonium ions, Nt - total nitrogen, - - not examined)


Table 5. Occurence of helminth eggs in slurry and in lagoon (A – *A. suum* eggs, Oe – *Oesophagostomum* sp. eggs, ND – not detected, - - not examined)

ground lagoon, and nitrogen (max. 9 854 mg.l-1 in sediment compared to 2 283 mg.l-1 in supernatant) on devitalization of developmental stages of endoparasites. The number of devitalised *A. suum* eggs increased towards to the bottom of lagoon. In the control groups,

> **OM (%)**

8.37 9333 1.17 49.21 50.79 1 885 2 138 5 778 5 963 8.13 11000 1.17 48.26 51.74 1 681 1 830 5 635 6 041 8.07 6170 1,70 43.21 56.79 1 643 2 241 7 344 9 652 8.09 4500 1.28 31.52 52.88 1 363 1 625 4 042 6 782 7.90 55100 1.12 34.90 65.10 1 359 2 437 3 913 7 298 8.08 8965 - - - 1 149 4 755 - - 7.87 7322 - - - 1 541 - - - - - - - - - -- - - 7.73 6367 - - - 5 358 9 854 - - 8.24 2494 1.72 32.11 67.89 840 1233 5513 11658 8.17 5897 0.73 51.16 48.84 1989 938 3740 3571 8.12 27186 1.19 45.41 54.59 915 1387 5402 6493 8.11 - 13.01 55.56 44.44 308 3909 72289 57831 - - - - - - - - - Table 4. Physico-chemical properties of sediment from stabilized pig sllury stored in lagoon (COD – chemical oxygen demand, DM - dry matter, IM - inorganic mater, OM - organic

**Soluble substances (mg.l-1)** 

**Insoluble substances (mg.l-1)** 

**NH4+ (mg.l-1)** 

**Nt (mg.l-1)** 

only 19.60 ± 1.80 % of *A. suum* eggs were devitalized (Table 6).

**DM (%)** 

**IM (%)** 

+ - ammonium ions, Nt - total nitrogen, - - not examined)

**Slurry Storage (month) and occurence of eggs per litre sample** 

**(raw)** Oe-2 ND ND A-5 ND ND ND - - - - - - ND ND ND

**(digested)** A-2 ND ND ND ND ND ND - - - - - - ND A-1 ND

**(lagoon)** ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND

**(lagoon)** ND ND A-6 ND ND ND ND ND ND ND ND ND ND A-2 ND ND

0 1 2 3 4 5 6 11 13 14 15 16 17 21 23 29

Table 5. Occurence of helminth eggs in slurry and in lagoon (A – *A. suum* eggs, Oe –

*Oesophagostomum* sp. eggs, ND – not detected, - - not examined)

**Storage** 

matter; NH4

**Input** 

**Output** 

**Supernatant** 

**Sediment** 

**(month) pH COD** 

**(mg.l-1)** 


Table 6. Damage of *A. suum* eggs during long term storage of anaerobic stabilized pig slurry in lagoon

#### **b) Anaerobic stabilisation of solid animal wastes**

The effect of anaerobic stabilisation of solid animal wastes (manure, dog excrements) with or without addition of lime on the survival of parasitic germs were studied under laboratory conditions. Two types of lime was used in the experiment: 1. quality dust lime and 2. dust rejects from lime production caught on the electrostatic precipitator. General characteristics of tested lime are given in Table 7.


Table 7. Physico-chemical properties of the tested types of lime

Pig manure (M) and dog excrements mixed with hay in the ratio of 1:5 (D) were used in the experiment. Organic wastes were mixed with tested lime in a different concentration and periodically stirred. The following variations were investigated in comparison to untreated (control) manure (CM) and untreated dog droppings (CD):


Samples for parasitological and physical and chemical examinations were collected after 0, 1, 3, 8, 14, 36 (UM, ML20 and M20) and after 0, 1, 2, 3, 7, 8, 9, 10, 14, 73 (UD, D20, D70) days of exposure. Three samples were taken and analysed at each of the given sampling intervals.

The physical and chemical properties of treated manure and dog excrements are given in Tables 8 - 13. Comparison of the changes in The physical and chemical properties of organic material during anaerobic stabilisation with or withou dust rejects is given in Fig. 1 – 5.

The Sanitation of Animal Waste Using Anaerobic Stabilization 61

**OM (%)** 

9.08±0.01 35.66±1.83 11.33±0.01 88.67±0.01 219.07±55,70 40758.43±1416.02 11.15:1 8.57±0.01 34.66±0.11 14.29±1.77 85.71±1.77 232.05±23,57 39116.17 ±207.87 11.24:1 9.61±0.01 35.20±4.23 19.21±4.89 80.79±4.89 395,72±2,48 41116.07±1205.26 10.12:1 9.78±0.01 37.56±1.93 22.33±1.06 77.67±1.06 309.78±95.04 44207.73±3222.05 9.05:1 9.01±0.01 37.17±0.29 20.58±0.48 79.42±0.48 370,89±8.22 23346.91±5147.86 18.06:1 9.39±0.02 33.21±0.18 22.46±1.97 77.54±1.97 82.25±2.55 12152.63±77.34 32.74:1 9.55±0.02 29.81±3.03 31.17±3.54 68.83±3.54 132.58±72.91 6556.92±818.39 54.92:1 9.49±0.03 31.96±1.13 31.46±0.36 68.54±0,36 124.07±0.16 6217.49±27.34 57.31:1 9.34±0.03 53.90±4.33 32.32±0.91 67.68±0.91 138.03±7.41 5435.17±2904.64 76.40:1 8.51±0.03 86.31±0.23 17.99±1.73 82.01±1.73 28.09±3.26 9159.80±1327.01 46.33:1 Table 11. Physico-chemical properties of the dog excrements during anaerobic stabilization

> **OM (%)**

8.41±0.05 37.21±0.01 16.04±4.81 83.96±4.81 400.57±47.84 45177.35±4724.10 9.64:1 11.21±0.02 44.47±0.91 39.37±0.10 60.63±0.10 12.51±8.65 32262.40±4212.96 9.66:1 9.34±0.03 56.45±15.15 62.63±19.97 37.37±19.97 36.17±7.84 16218.95±2664.67 12.44:1 8.58±0.01 57.28±33.23 60.29±28.06 39.71±28.06 645.10±362.56 45266.01±19058.77 4.23:1 9.08±0.01 45.11±6.79 43.58±0.64 56.42±0.64 225.45±91.01 22104.48±11603.90 15.37:1 9.13±0.01 43.90±2.84 41.87±0.96 58.13±0.96 439.78±141.28 18254.61±1760.78 16.74:1 9.27±0.05 68.66±1.32 27.61±0.60 72.39±0.60 398.59±2.51 18083.74±303.53 20.86:1 9.12±0.04 64.15±0.16 42.28±0.71 57.64±0.71 349.02±10.08 16966.79±191.73 17.70:1 8.91±0.03 60.02±0.98 49.20±4.49 50.80±4.49 338.50±24,95 17963.19±457.92 14.71:1 8.69±0.01 89.06±0.01 38.85±3.90 61.15±3.90 74.54±26.60 13972.75±1214.80 22.56:1

Table 12. Physico-chemical properties of the dog excrements mixed with dust rejects in a concentration of 20 g.kg-1 during anaerobic stabilization (D20) (DM - dry matter, IM - inorganic

Table 13. Physico-chemical properties of the dog excrements mixed with dust rejects in a concentration of 20 g.kg-1 during anaerobic stabilization (D70) (DM - dry matter, IM - inorganic

**OM (%)** 

9.08±0.01 35.66±1.83 11.33±0.01 88.67±0,01 219.07±55.70 40758.43±1416.02 11.15:1 12.58±0.04 43.11±1.51 58.48±9.02 41.52±9,02 41.04±42.79 13041.67±2498.12 16.22:1 12.68±0.01 46.81±0.17 62.89±2.38 37.11±2,38 10.19 4555.21±936.46 42.69:1 12.64±0.01 44.10±1.95 57.53±1.39 42.47±1,39 20.65±14.40 6868.28±1649.01 32.67:1 12.36±0.01 45.50±0.21 60.84±0.47 39.16±0,47 140.34±9.77 26830.72±6801.00 7.73:1 10.63±0.01 45.22±0.48 62.63±2.26 37.37±2,26 131.32±2.98 14216.80±5981.61 15.04:1 10.12±0.01 45.60±1.23 60.40±4.67 39.60±4.67 82.59 16161.23±10202.44 16.18:1 10.06±0.02 46.75±1.09 63.09±0.21 36.91±0.21 85.65±10.62 13399.86±759.04 14.14:1 9.82±0.01 52.21±1.08 65.03±0.80 34.97±0.80 14.28 19371.98±1147.30 9.21:1 8.97±0.02 87.17±0.47 40.50±1.92 59.50±1.92 2.20±0.08 12440.27±566.93 24.43:1

**NH4+ (mg.kg-1 DM)**

**NH4+ (mg.kg-1 DM)**

+ - ammonium ions, Nt - total nitrogen, - - not examined)

+ - ammonium ions, Nt - total nitrogen, - - not examined)

**NH4+ (mg.kg-1 DM)**

**Nt (mg.kg-1 DM) C:N** 

+ - ammonium ions,

**Nt (mg.kg-1 DM) C:N** 

**Nt**

**(mg.kg-1 DM) C:N** 

**IM (%)** 

(CD) (DM - dry matter, IM - inorganic mater, OM - organic matter; NH4

**IM (%)** 

**IM (%)** 

**Storage** 

**Storage** 

**Storage** 

**(days) pH DM** 

Nt - total nitrogen, - - not examined)

**(%)** 

**(%)** 

**(days) pH DM** 

mater, OM - organic matter; NH4

mater, OM - organic matter; NH4

**(days) pH DM** 

**(%)** 


Table 8. Physico-chemical properties of the pig manure during anaerobic stabilization (CM) (DM - dry matter, IM - inorganic mater, OM - organic matter; NH4 + - ammonium ions, Nt total nitrogen)


Table 9. Physico-chemical properties of the pig manure mixed with dust rejects in a concentration of 20 g.kg-1 during anaerobic stabilization (M20) (DM - dry matter, IM inorganic mater, OM - organic matter; NH4+ - ammonium ions, Nt - total nitrogen)


Table 10. Physico-chemical properties of the pig manure mixed with quick lime in a concentration of 20 g.kg-1 during anaerobic stabilization (ML20) (DM - dry matter, IM inorganic mater, OM - organic matter; NH4 + - ammonium ions, Nt - total nitrogen, - - not examined)

The Sanitation of Animal Waste Using Anaerobic Stabilization 61

**OM (%)** 

8.47±0.58 33.22±6.88 8.09±2.57 91.91±2.57 120.89±7.05 13789.52±2356.62 34.27:1 8.57±0.02 20.66±4,29 10.41±0.72 89.58±0.72 257.65±10.10 51930.16±421.47 8.84:1 9.52±0.06 28.06±5.41 6.03±0.11 93.37±0.11 176.37±8.09 46522.24±2310.56 10.27:1 9.28±0.02 23.50±4.12 8.34±2.66 91.66±2.66 214.60±7.92 49872.94±1715.15 9.41:1 8.26±0.02 14.99±0.39 9.12±1.14 90.88±1.14 510.81±11.32 58608.01±2701.82 7.97:1 8.27±0.06 14.36±0.12 9.48±0.13 90.52±0.13 48.75±2.80 32698.26±2378.98 14.13:1

Table 8. Physico-chemical properties of the pig manure during anaerobic stabilization (CM)

**OM (%)** 

8.47±0.58 33.22±6.88 8.09±2.57 91.91±2.57 120.89±7.05 13789.52±2356,62 34.27:1 12.97±0.02 41.57±2.46 58.88±17.14 41.12±17.14 69.64±4.28 125901.56±873.31 8.11:1 12.76±0.01 45.96±3.72 39.91±7.76 60.09±7.76 111.75±9.84 18866,51±3349.86 16.32:1 10.39±0.01 26.91±2.16 16.95±2.67 83.05±2.67 236.01±7.05 52051.28±1482.36 8.17:1 8.29±0.01 21.47±5.22 14.36±3.41 85.64±3.41 326.22±17.94 56824.87±2746.13 7.72:1 8.29±0.01 20.11±2.32 13.41±1.12 86.19±1.12 225.21±22.47 71771.76±1722.51 6.14:1

> **OM (%)**

8.47±0.58 33.22±6.88 8.09±2.57 91.91±2.57 120.89±7.05 13789.52±2356,62 34.27:1 12.86±0.03 30.33±3.87 48.90±15.23 51.10±15.23 126.24±9.84 37815.69±1860.53 6.97:1 12.96±0.01 37.31±3.89 57.40±5.92 42.60±5.92 130.15±9.01 35790.24±2332.63 6.08:1 11.56±0.02 25.37±0.95 48.67±3.35 51.33±3.35 176.67±10.10 81616.08±3704.40 3.21:1 9.36±0.01 20.30±2.17 34.12±1.12 65.88±1.12 206.99±17.83 44057.78±2515.94 7.66:1 8.76±0.01 20.08±1.56 32.48±3.46 67.52±3.46 181.37±25.75 65746.86±2677.51 5.25:1

**NH4+ (mg.kg-1 DM)**

**NH4 + (mg.kg-1 DM)**

**NH4+ (mg.kg-1 DM)**

+ - ammonium ions, Nt - total nitrogen, - - not

**Nt (mg.kg-1 DM) C:N** 

+ - ammonium ions, Nt -

**Nt (mg.kg-1 DM) C:N** 

**Nt (mg.kg-1 DM) C:N** 

**IM (%)** 

(DM - dry matter, IM - inorganic mater, OM - organic matter; NH4

**IM (%)** 

Table 9. Physico-chemical properties of the pig manure mixed with dust rejects in a concentration of 20 g.kg-1 during anaerobic stabilization (M20) (DM - dry matter, IM inorganic mater, OM - organic matter; NH4+ - ammonium ions, Nt - total nitrogen)

Table 10. Physico-chemical properties of the pig manure mixed with quick lime in a concentration of 20 g.kg-1 during anaerobic stabilization (ML20) (DM - dry matter, IM -

**IM (%)** 

**Storage** 

total nitrogen)

**Storage** 

**Storage** 

examined)

**(days) pH DM** 

**(days) pH DM** 

**(days) pH DM** 

**(%)** 

**(%)** 

**(%)** 

inorganic mater, OM - organic matter; NH4


Table 11. Physico-chemical properties of the dog excrements during anaerobic stabilization (CD) (DM - dry matter, IM - inorganic mater, OM - organic matter; NH4 + - ammonium ions, Nt - total nitrogen, - - not examined)


Table 12. Physico-chemical properties of the dog excrements mixed with dust rejects in a concentration of 20 g.kg-1 during anaerobic stabilization (D20) (DM - dry matter, IM - inorganic mater, OM - organic matter; NH4 + - ammonium ions, Nt - total nitrogen, - - not examined)


Table 13. Physico-chemical properties of the dog excrements mixed with dust rejects in a concentration of 20 g.kg-1 during anaerobic stabilization (D70) (DM - dry matter, IM - inorganic mater, OM - organic matter; NH4 + - ammonium ions, Nt - total nitrogen, - - not examined)

The Sanitation of Animal Waste Using Anaerobic Stabilization 63

Fig. 4. Comparison of the changes in Nt of organic material during anaerobic stabilisation

<sup>+</sup> of organic material during anaerobic stabilisation

Fig. 3. Comparison of the changes in NH4

with or without dust rejects

with or without dust rejects

Fig. 1. Comparison of the changes in pH of organic material during anaerobic stabilisation with or without dust rejects

Fig. 2. Comparison of the changes in DM of organic material during anaerobic stabilisation with or without dust rejects

Fig. 1. Comparison of the changes in pH of organic material during anaerobic stabilisation

Fig. 2. Comparison of the changes in DM of organic material during anaerobic stabilisation

with or without dust rejects

with or without dust rejects

Fig. 3. Comparison of the changes in NH4 <sup>+</sup> of organic material during anaerobic stabilisation with or without dust rejects

Fig. 4. Comparison of the changes in Nt of organic material during anaerobic stabilisation with or without dust rejects

The Sanitation of Animal Waste Using Anaerobic Stabilization 65

devitalisation of 65.65 ± 2.84 % and at a concentration of 70 g.kg-1 77.05 ± 2.36 % of model unembryonated *A. suum* eggs within 24 hours (Table 15). *A. suum* eggs were totally devitalised as early as within 8 days in dogs' excrements after application of dust rejects at a concentration of 70 g.kg-1 and within 21 days after application of dust rejects at a concentration of 20 g.kg-1 due to the changes in physical and chemical properties of the stabilised materials (Tables 12, 13). 57.23±3.21 % of eggs were devitalised in the control

12.62±1.14 12.62±1,14 12.62±1.14 35.70±2.46 65.65±2.84\*\* 77.05±2.36\*\*\* 54.43±10.66\* 68.65±3.89\*\* 82.30±4.81\*\*\* 67.00±2.55\*\* 75.15±1.21\*\* 87.60±3.98\*\*\* 62.65±4.03\*\* 76.25±5.41\*\* 97.13±3.97\*\*\* 59.80±2.71\* 76.93±2.69\*\*\* 100\*\*\* 61.87±2.90\* 82.30±4.81\*\*\* 100\*\*\* 62.85±4.03\* 85.69±1.45\*\*\* 100\*\*\* 61.96±3.26\* 95.69±6.35\*\*\* 100\*\*\* 55.65±2.36\* 100\*\*\* 100\*\*\* 57.23±3.21\* 100\*\*\* 100\*\*\* Tab. 15. Survival of *A. suum* eggs during anaerobic stabilisation of manure with or without lime (\* Significance at the level P<0.05; \*\* Significance at the level P<0.01; \*\*\* Significance at

Our experiment showed that stabilisation of organic wastes with dust rejects result in complete devitalisation of *A. suum* eggs (Table 14, 15). The most important physico-chemical factors affecting viability of helminth eggs include pH and ammonia. We observed the highest pH and ammonia content especially in the organic wastes treated with tested types of lime. One of our previous studies (Ondrašovič et al., 2002) on the effect of ammonium hydroxide on *A. suum* eggs showed that at 10 % concentration of NH4OH, pH 12.16 and exposure time 180 min. approx. 94 % *A. suum* eggs were devitalised. Pescon and Nelson (2005) also reported that environmentally relevant concentrations of ammonia may significantly increase the rate of *Ascaris* eggs inactivation during alkaline stabilization*.* 

Processes of slurry anaerobic stabilization represent an effective method in terms of energy, since the substantial portion of energy present in easily decomposable organic constituents of the substrate is acquired in the form of biogas. Non-decomposed organic matter is well stabilized from hygienic point of view. Anaerobic stabilization increases the proportion of biogenic element (especially nitrogen) converting stabilized excrements into quality fertilizer. Anaerobically stabilized pig slurry stored in lagoon significantly influence the quality and quantity of grasses, depending on the dose of slurry used and on weather conditions. From the nutritional point of view, the sludge (sediment) from ground lagoon is

CD P20 P70

without dust reject in the end of experiment (Table 15).

the level P<0.001)

**3. Conclusion** 

**Storage (days) Demaged** *A. suum* **eggs (x%±SD)** 

Fig. 5. Comparison of the changes in C:N ratio of organic material during anaerobic stabilisation with or without dust rejects

The Table 14 indicates that a 24 hour after application of both types of lime at concentration 20 g.kg-1 manure more than 80 % of model unembryonated *A. suum* eggs were devitalised. *A. suum* eggs were totally devitalised as early as till 36 days after application of lime in manure. 58.13±6.89 % of eggs were devitalised in the control without dust reject in the end of experiment.


Table 14. Survival of *A. suum* eggs during anaerobic stabilisation of the dog excrements with or without lime (\* Significance at the level P<0.05; \*\* Significance at the level P<0.01; \*\*\* Significance at the level P<0.001)

For the sanitation of animal excrenemts, the use of dust rejects from lime production, at more affordable price than quality lime, is very suitable. An application of dust rejects to the mixed dogs' excrements at a concentration of 20 g.kg-1 of organic wastes, resulted in a

Fig. 5. Comparison of the changes in C:N ratio of organic material during anaerobic

The Table 14 indicates that a 24 hour after application of both types of lime at concentration 20 g.kg-1 manure more than 80 % of model unembryonated *A. suum* eggs were devitalised. *A. suum* eggs were totally devitalised as early as till 36 days after application of lime in manure. 58.13±6.89 % of eggs were devitalised in the control without dust reject in the end

16.43±1.14 16.43±1.14 16.43±1.14 36.31±2.46 82.41±8.49\*\*\* 80.68±6.75\*\*\* 55.10±10.72\*\* 87.23±11.06\*\*\* 89.85±5.10\*\*\* 59.14±1.74\*\* 98.96±1.80\*\*\* 82.22±16.78\*\*\* 56.11±19.64\* 97.13±3.77\*\*\* 97.33±4.62\*\*\* 58.13±6.89\*\* 100\*\*\* 100\*\*\* Table 14. Survival of *A. suum* eggs during anaerobic stabilisation of the dog excrements with or without lime (\* Significance at the level P<0.05; \*\* Significance at the level P<0.01; \*\*\*

For the sanitation of animal excrenemts, the use of dust rejects from lime production, at more affordable price than quality lime, is very suitable. An application of dust rejects to the mixed dogs' excrements at a concentration of 20 g.kg-1 of organic wastes, resulted in a

**Demaged** *A. suum* **eggs (x%±SD) CM ML20 M20** 

stabilisation with or without dust rejects

Significance at the level P<0.001)

of experiment. **Storage (days))** 

devitalisation of 65.65 ± 2.84 % and at a concentration of 70 g.kg-1 77.05 ± 2.36 % of model unembryonated *A. suum* eggs within 24 hours (Table 15). *A. suum* eggs were totally devitalised as early as within 8 days in dogs' excrements after application of dust rejects at a concentration of 70 g.kg-1 and within 21 days after application of dust rejects at a concentration of 20 g.kg-1 due to the changes in physical and chemical properties of the stabilised materials (Tables 12, 13). 57.23±3.21 % of eggs were devitalised in the control without dust reject in the end of experiment (Table 15).


Tab. 15. Survival of *A. suum* eggs during anaerobic stabilisation of manure with or without lime (\* Significance at the level P<0.05; \*\* Significance at the level P<0.01; \*\*\* Significance at the level P<0.001)

Our experiment showed that stabilisation of organic wastes with dust rejects result in complete devitalisation of *A. suum* eggs (Table 14, 15). The most important physico-chemical factors affecting viability of helminth eggs include pH and ammonia. We observed the highest pH and ammonia content especially in the organic wastes treated with tested types of lime. One of our previous studies (Ondrašovič et al., 2002) on the effect of ammonium hydroxide on *A. suum* eggs showed that at 10 % concentration of NH4OH, pH 12.16 and exposure time 180 min. approx. 94 % *A. suum* eggs were devitalised. Pescon and Nelson (2005) also reported that environmentally relevant concentrations of ammonia may significantly increase the rate of *Ascaris* eggs inactivation during alkaline stabilization*.* 
