Livestock Wastewater Treatment Plants Research Articles

The significant impact of MPs in the industrial/municipal effluents on the MPs abundance in the Nakdong River, South Korea

Owing to extensive plastic consumption, wastewater from households, business establishments, and industrial activities have been recognised as a significant contributor to microplastics (MPs) in aquatic environments. This case study represents the first investigation of MPs in the Nakdong River, Republic of Korea, that traverses through the largest industrial complex midstream and densely populated cities of Daegu and Busan downstream before flowing into the sea. Monitoring of MP abundance in effluents discharged from three municipal, two industrial, and one livestock wastewater treatment plant (WWTP) into the Nakdong River was conducted over four seasons from August 2022 to April 2023. Identification and quantification of MPs were performed using micro-Fourier transform infrared spectrometry. Seasonal variation in MPs in the Nakdong River was found to be strongly influenced by the nearest upstream WWTPs and rivers, exhibiting a linear relationship that decreased gradually with increasing distance from the WWTPs. The average concentrations of MPs in the six effluent sources ranged from 101 ± 13 to 490 ± 240 particles/L during the yearly monitoring period, while MP concentrations in the river ranged between 79 ± 25 and 120 ± 43 particles/L. Industrial effluents contained higher amounts of discharged MPs (314 ± 78 particles/L) than municipal sources (201 ± 61 particles/L). Notably, two municipal WWTPs, located in the highly densely populated city, discharged the highest total MP amounts per day and released the greatest volumes of effluents. This study provides valuable insights into the monitoring and impact of effluents on MPs in rivers, which could inform MP treatment and management strategies for in river and marine environments.

Ammonia emissions from a dairy housing and wastewater treatment plant quantified with an inverse dispersion method accounting for deposition loss

ABSTRACT Ammonia (NH3) emissions negatively impact air, soil, and water quality, hence human health and biodiversity. Significant emissions, including the largest sources, originate from single or multiple structures, such as livestock facilities and wastewater treatment plants (WWTPs). The inverse dispersion method (IDM) is effective in measuring total emissions from such sources, although depositional loss between the source and point of measurement is often not accounted for. We applied IDM with a deposition correction to determine total emissions from a representative dairy housing and WWTP during several months in autumn and winter in Switzerland. Total emissions were 1.19 ± 0.48 and 2.27 ± 1.53 kg NH3 d−1 for the dairy housing and WWTP, respectively, which compared well with literature values, despite the paucity of WWTP data. A concurrent comparison with an inhouse tracer ratio method at the dairy housing indicated an offset of the IDM emissions by < 20%. Diurnal emission patterns were evident at both sites mostly driven by changes in air temperature with potential lag effects such as following sludge agitation. Modeled deposition corrections to adjust the concentration loss detected at the measurement point with the associated footprint were 22–28% of the total emissions and the cumulative fraction of deposition to emission modeled with distance from the source was between 7% and 12% for the measurement distances (60–150 m). Although estimates of depositional loss were plausible, the approach is still connected with substantial uncertainty, which calls for future validation measurements. Longer measurement periods encompassing more management activities and environmental conditions are required to assess predictor variable importance on emission dynamics. Combined, IDM with deposition correction will allow the determination of emission factors at reduced efforts and costs, thereby supporting the development and assessment of emission reducing methods and expand the data availability for emission inventories. Implications: Ammonia emissions must be measured to determine emission factors and reporting national inventories. Measurements from structures like farms and industrial plants are complex due to the many different emitting surfaces and the building configuration leading to a poor data availability. Micrometeorological methods provide high resolution emission data from the entire structure, but suffer from uncertainties, as the instruments must be placed at a distance from the structure resulting in a greater loss of the emitted ammonia via dry deposition before it reaches the measurement. This study constrains such emission measurements from a dairy housing and wastewater treatment plant by applying a simple correction to account for the deposition loss and compares the results to other methods.

117 Optimization of the Measurement Method for Airborne Endotoxins in Workplace Atmospheres: a Laboratory and Field Study

Abstract Endotoxins are lipopolysaccharides present in the outer membrane of most Gram-negative bacteria. They can become airborne by working tasks, techniques and processes that generate aerosols from materials contaminated by these microorganisms and can cause harmful effects on the health of workers by inhalation. Since 2005, INRS has been proposing a method for measuring endotoxins, which use a 2 L/min closed-face cassette sampling and an analysis by chromogenic LAL assay, mainly following EN 14031 standard. However, the evolution of knowledge and the lack of some validation data led to new experimental investigations in order to optimize this method: optimization of the sampling (filters type) and the extraction protocol (liquid volume, duration, methodology) as well as the influence of sample storage have been studied. A bubbler-type generator was used to produce a bioaerosol from a mixture of three bacteria to obtain controlled concentrations of 50 to 10000 EU/m3. These laboratory tests confirmed a better recovery of endotoxins when extraction is carried out directly in the cassette and let possible to fix the volume (5 mL) and the duration (20 min) of elution. PVC filters appear to result in lower endotoxins recovery compared to fiberglass, PTFE or PC filters. Additional field tests were done in different workplaces as livestock farm (pig, cow), grain processing, composting and wastewater treatment plants. Comparison of filters results in these occupational environments as well as the influence of samples storage at room temperature during 8 days will be discussed.

Phage-Based Biocontrol of Antibiotic-Resistant Bacterium Isolated from Livestock Wastewater Treatment Plant

The presence of antibiotic-resistant bacteria (ARB) in receiving water can severely threaten the aquatic environment and human health. The treated effluent containing ARB in some livestock wastewater treatment plants (WWTPs) is returned to the municipal WWTP to reduce the residual ammonia and phosphorus concentrations. ARBs are widespread through wastewater treatment processes and are discharged into river and lake. This study highlights that the isolated lytic phage could reduce ARB isolated from livestock WWTPs and apply phage-based biocontrol in mixed cultures. ARB and lytic phages were isolated from livestock wastewater and used in a batch reactor with diverse cultures. The isolated bacterium was from the Aeromonas species and was resistant to various antibiotics (penicillin, tetracycline, colistin, and kanamycin), indicating multi-drug resistance and biofilm formation. The isolated lytic phage successfully infected Aeromonas species in pure culture and was relatively stable in terms of pH, temperature, and toxic chemicals. The multiplicity of infection (MOI) was examined to determine the proper phage number to kill the host bacterium. The optimal number to control the isolated ARB was a 1:100 phage-to-host ratio. Scanning electron microscopy showed that lytic phages reduced bacterial growth and biofilm formation. Phage-mediated biocontrol was applied in a batch reactor with mixed cultures. Pyrosequencing data from the batch reactor indicated that lytic phages reduced the proportion of the isolated ARB from 65.7 to 20% in 24 h. This study provides evidence for the possible application of lytic phages to control ARB in treated wastewater and an alternative method to prevent the widespread exposure of ARB without producing chemical byproducts.

Bacillus subtilis reduces antibiotic resistance genes of animal sludge in vermicomposting by improving heat stress tolerance of Eisenia foetida and bacterial community adjustment

Antibiotic resistance genes (ARGs) in livestock industry have been recognized as a kind of pollutant. The effect of Bacillus subtilis (B. subtilis) as an additive for the reduction of ARGs in animal sludge from livestock and poultry wastewater treatment plant during vermicomposting was investigated. We also evaluated the oxidative stress level and growth of earthworms, Eisenia foetida, bacterial community succession, and the quality of the end products. Two treatments were conducted using B. subtilis, one at 18 °C and another at 28 °C. Controls were setup without the bacteria. The results showed that inoculation of B. subtilis promoted the degradation of organics at 28 °C and increased the germination index to 236%. The increased activities of the superoxide dismutase (1.69 U/mg pr) and catalase (8.05 U/mg pr) and the decreased activity of malondialdehyde (0.02 nmol/mg pr) by B. subtilis at 28 °C showed that the earthworms were relieved of heat stress. The addition of B. subtilis reduced the abundance of 32 target ARGs, including integron (intI-1), transposase (IS613) and resistant genes, such as sulfonamide (sul2), quinolone (oprJ), macrolide-lincosamide-streptogramin group B (ermF, ermB), tetracycline (tetL-02, tetX), β-lactama (blaOXA10-01) and aminoglycoside [strB, aac(6′)-Ib(aka aacA4)-01, aac(6′)-Ib(aka aacA4)-02]. Organic matter degrading Membranicola, Paludisphaera, Sphingorhabdus and uncultured bacterium belonging to the order Chitinophagales, nitrifying and nitrogen-fixing Singulisphaera and Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium, soil remediating Achromobacter, and plant growth promoting Kaistia, Galbibacter and Ilumatobacter were increased significantly (P < 0.05). However, the growth of harmful bacteria such as Burkholderiaceae was inhibited in the vermicompost. In earthworm guts, the probiotic Mesorhizobium was promoted, while the pathogenic uncultured bacterium belonging to the family Enterobacteriaceae was reduced. Besides, B. subtilis enhanced the host relationships between bacteria and ARGs. These findings might be helpful in the removal of ARGs in animal wastes and in understanding the synergy between earthworms and microorganisms.

Acute stress of the typical disinfectant glutaraldehyde-didecyldimethylammonium bromide (GD) on sludge microecology in livestock wastewater treatment plants: Effect and its mechanisms

Glutaraldehyde and didecyldimethylammonium bromide (GD) is a disinfectant widely used to prevent African swine fever (ASF) in livestock farms. However, the effect of residual GD on the activated sludge microbial ecology of receiving wastewater treatment plants (WWTPs) remains largely unknown. In this study, seven simulated systems were established to research the effects of GD on WWTPs and reveal the underlying mechanisms of microecological responses to GD at different concentrations. Both the nitrogen and carbon removal rates decreased with increasing GD concentrations, and nitrogen metabolism was inhibited more obviously, but the inhibition weakened with increasing stress duration. Microorganisms activated their SoxRS systems to promote ATP synthesis and electron transfer to support the hydrolysis and efflux of GD by producing a small number of ROS when exposed to GD at less than 1 mg/L. The overproduction of ROS led to a decrease of antioxidant and nitrogen removal enzyme activities, and upregulation of the porin gene increased the risk of GD entering the intracellular space upon exposure to GD at concentrations higher than 1 mg/L. Some denitrifiers survived via resistance and their basic capabilities of sugar metabolism and nitrogen assimilation. Notably, low concentrations of disinfectants could promote vertical and horizontal transfer of multiple resistance genes, especially aminoglycosides, among microorganisms, which might increase not only the adaptation capability of denitrifiers but also the risk to ecological systems. Therefore, the risks of disinfectants targeting ASF on ecology and health as well as the effects of disinfectant residuals from the COVID-19 epidemic should receive more attention.

Draft Genome Sequence of Stenotrophomonas daejeonensis Strain NLF4-10 Isolated from Livestock Wastewater.

ABSTRACTHere, we report the draft genome sequence of Stenotrophomonas daejeonensis strain NLF4-10, isolated from a livestock wastewater treatment plant in Nonsan, Republic of Korea. The whole-genome sequence of S. daejeonensis strain NLF4-10 was analyzed using the Pacific Biosciences Sequel and Illumina NovaSeq sequencing platforms. The genome comprises a 3,655,148 bp chromosome with a GC content of 68%, 3,274 coding DNA sequences (CDSs), 59 transfer RNAs (tRNAs), and 4 noncoding RNAs (ncRNAs).

농경지역의 대규모 축산단지에서 배출되는 축산계 부하의 점오염과 비점오염 분류와 정량화

Livestock manure discharged from agricultural areas has different treatment and fertilization processes depending on the type of livestock. Swine manure is generally treated in livestock wastewater treatment plants and then sprayed as liquid fertilizer or discharged into rivers, whereas cattle manure is composted in livestock excreta resource facilities such as biogas plants, and a large amount is applied to the land. However, the source unit of the livestock manure load applied in Korea''s total maximum daily load (TMDL) is not divided into point pollution type and non-point pollution type. The species and pollution load of livestock manure generated in Yongji Watershed where swine are the main livestock, and Dukcheon Watershed where cattle are mainly raised were investigated through a series of measurements and calculations. The result of this study showed the pollution load of livestock manure was clearly classified into PS type and NPS type, and in particular, the NPS pollution load was relatively large. As for the results measured in two watersheds of different livestock breeds, swine and cattle, BOD and TP showed high EMC concentrations in cattle breeding areas, whereas TN showed significantly higher values in swine breeding zones. This finding led us to conclude that there are differences in the water quality management criteria to be focused on depending on the type of livestock. In addition, the load of NPS was fluctuated sensitively to the rainfall intensity, and it implied that the rainfall intensity should be considered as one of the influencing factors when a pollution load of livestock manure is applied to the TMDL.

Distribution of Antibiotic-Resistant Bacteria in the Livestock Farm Environments

The surroundings of livestock farms, including dairy farms, are known to be a major source of development and transmission of antibiotic-resistant bacteria. To control antibioticresistant bacteria in the livestock breeding environment, farms have installed livestock wastewater treatment facilities to treat wastewater before discharging the final effluent in nearby rivers or streams. These facilities have been known to serve as hotspots for inter-bacterial antibiotic-resistance gene transfer and extensively antibiotic-resistant bacteria, owing to the accumulation of various antibiotic-resistant bacteria from the livestock breeding environment. This review discusses antibiotic usage in livestock farming, including dairy farms, livestock wastewater treatment plants as hotspots for antibiotic resistant bacteria, and nonenteric gram-negative bacteria from wastewater treatment plants, and previous findings in literature.

Sulfonamide degradation and metabolite characterization in submerged membrane photobioreactors for livestock excreta treatment

Residual veterinary antibiotics have been detected in livestock wastewater treatment plants. Despite the long retention time, antibiotic treatment efficiency has shown clear limitations. In this study, we evaluated submerged membrane photobioreactors (SMPBR) during sulfonamide antibiotic-containing livestock wastewater treatment under mixotrophic and photoautotrophic conditions. The results showed that microalgal sulfur degradation and consumption under mixotrophic conditions accelerated the biomass concentration increase to 2800 mg VSS/L compared to the 1800 mg VSS/L measured under photoautotrophic conditions. Although microalgal metabolites, such as soluble microbial products and extracellular polymeric substances, might cause membrane fouling in the SMPBR, we proved that microalgae could remove sulfonamide and release degradation-associated sulfur, along with nitrogen and phosphorus. Moreover, this study confirms the statistical correlation between metabolites and sulfonamides. In summary, the results of this study provide promising insights into antibiotic-containing livestock wastewater treatment.

Occurrence and Removal of Veterinary Antibiotics in Livestock Wastewater Treatment Plants, South Korea

In this study, livestock wastewater treatment plants in South Korea were monitored to determine the characteristics of influent and effluent wastewater, containing four types of veterinary antibiotics (sulfamethazine, sulfathiazole, chlortetracycline, oxytetracycline), and the removal efficiencies of different treatment processes. Chlortetracycline had the highest average influent concentration (483.7 μg/L), followed by sulfamethazine (251.2 μg/L), sulfathiazole (230.8 μg/L) and oxytetracycline (25.7 μg/L), at five livestock wastewater treatment plants. Sulfathiazole had the highest average effluent concentration (28.2 μg/L), followed by sulfamethazine (20.8 μg/L) and chlortetracycline (11.5 μg/L), while no oxytetracycline was detected. For veterinary antibiotics in the wastewater, a removal efficiency of at least 90% was observed with five types of treatment processes, including a bio-ceramic sequencing batch reactor, liquid-phase flotation, membrane bioreactor, bioreactor plus ultrafiltration (BIOSUF) and bio best bacillus systems. Moreover, this study evaluated the removal efficiency via laboratory-scale experiments on the conventional contaminants, such as organic matter, nitrogen, phosphorus and veterinary antibiotics. This was done using the hydraulic retention time (HRT), under three temporal conditions (14 h, 18 h, 27 h), using the anaerobic–anoxic–oxic (A2O) process, in an attempt to assess the combined livestock wastewater treatment process where the livestock wastewater is treated until certain levels of water quality are achieved, and then the effluent is discharged to nearby sewage treatment plants for further treatment. The removal efficiencies of veterinary antibiotics, especially oxytetracycline and chlortetracycline, were 86.5–88.8% and 87.9–90.8%, respectively, exhibiting no significant differences under various HRT conditions. The removal efficiency of sulfamethazine was at least 20% higher at HRT = 27 h than at HRT = 14 h, indicating that sulfamethazine was efficiently removed in the A2O process with increased HRT. This study is expected to promote a comprehensive understanding of the behavior and removal of veterinary antibiotics in the livestock wastewater treatment plants of South Korea.

Comamonas flocculans sp. nov., a Floc-Forming Bacterium Isolated from Livestock Wastewater.

A Gram-negative, aerobic, non-motile, rod-shaped, floc-forming, and non-spore-forming bacterium, designated as NLF-7-7T, was isolated from the biofilm of a sample collected from a livestock wastewater treatment plant in Nonsan, Republic of Korea. Strain NLF-7-7T, forms a visible floc and grows in the flocculated state. Cells of strain NLF-7-7T grew optimally at pH 6.5 and 30°C and in the presence of 0.5% (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain NLF-7-7T belonged to the family Comamonadaceae, and was most closely related to Comamonas badia DSM 17552T (95.8% similarity) and Comamonas nitrativorans 23310T (94.0% similarity). The phylogenetic and phenotypic data indicate strain NLF-7-7T is clearly distinguished from the Comamonas lineage. The major cellular fatty acids were C10:0 3OH, C16:0, and summed feature 3 (C16:1 ω6c/C16:1 ω7c). The respiratory quinone was Q-8. The polar lipids were composed of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, and an unidentified aminolipid. The DNA G+C content of strain NLF-7-7 was 68.0mol%. Based on the phenotypic, chemotaxonomic, and phylogenetic properties, strain NLF-7-7T represents a novel species of the genus Comamonas, for which the name Comamonas flocculans sp. nov. is proposed. The type strain is C. flocculans NLF-7-7T (=KCTC 62943T). The GenBank/EMBL/DDBJ accession number for the 16S rRNA gene sequence of Comamonas flocculans NLF-7-7T is MN527436. The whole-genome shotgun BioProject Number is PRJNA555370 with the Accession Number CP042344.

Contamination of Metal Elements in Livestock Wastewater Treatment Plants in Korea

Contamination of Metal Elements in Livestock Wastewater Treatment Plants in Korea

Antibiotic resistance genes and intI1 prevalence in a swine wastewater treatment plant and correlation with metal resistance, bacterial community and wastewater parameters

The livestock wastewater treatment plant represents an important reservoir of antibiotic resistance determinants in the environment. The study explored the prevalence of five antibiotic resistance genes (ARGs, including sulI, tetA, qnrD, mphB and mcr−1) and class 1 integron (intI1) in a typical livestock wastewater treatment plant, and analyzed their integrated association with two metal resistance genes (copA and czcA), two pathogens genes (Staphylococcus and Campylobacter), bacterial community and wastewater properties. Results indicated that all investigated genes were detected in the plant. The treatment plant could not completely remove ARGs abundances, with up to 2.2 × 104~3.7 × 108 copies/L of them remaining in the effluent. Mcr−1 was further enriched by 27-fold in the subsequent pond. The correlation analysis showed that mphB significantly correlateed with tetA and intI. Mcr−1 strongly correlated with copA. MphB and intI significantly correlated with czcA. The correlations implied a potential co-selection risk of bacterial resistant to antibiotics and metals. Redundancy analyses indicated that qnrD and mcr−1 strongly correlated with 13 and 14 bacterial genera, respectively. Most ARGs positively correlated to wastewater nutrients, indicating that an efficient reduction of wastewater nutrients would contribute to the antibiotic resistance control. The study will provide useful implications on fates and reductions of ARGs in livestock facilities and receiving environments.

Investigation of the interaction between the fate of antibiotics in aquafarms and their level in the environment

China is the largest freshwater aquaculture producer and antibiotics consumer in the world, and rivers in China are generally polluted by antibiotics. However, there is little information available regarding the linkage of antibiotics in aquaculture and the aquatic environment. Therefore, this study investigated the fate of antibiotics in several open water culture-based freshwater aquafarms, including integrated livestock/fish systems and non-integrated fish ponds, and explored the contamination profiles of antibiotics in the Beijiang River. Then the study tried to clarify the two-way interaction of antibiotics in aquaculture and the environment. The results showed that, when compared with the effluent from livestock farms and wastewater treatment plants, the contribution of antibiotics from non-integrated fish pond water without livestock sewage input was limited, while that of effluent from the integrated livestock/fish system was quite high. The total concentrations of antibiotics detected in the aquafarm source water were similar to those in the upper river water and generally higher than those in the corresponding fish pond water, implying that the occurrence of antibiotics in intensive aquafarms can mainly be attributed to the antibiotic residues in nearby river water. Overall, the results underscore the need to develop a sewage infrastructure for the treatment of effluent from integrated livestock/fish aquafarms, and suggest that open water culture-based fish farms should be located far from seriously contaminated sections of rivers.

Determination of 4-nonylphenol and 4- tert -octylphenol compounds in various types of wastewater and their removal rates in different treatment processes in nine wastewater treatment plants of Iran

Abstract Alkylphenols (APs), considered as xenoestrogenic compounds, mainly exist as 4-nonylphenol (4-NP) and 4- tert -octylphenol (4- t -OP) in environments. The high stability and accumulation of APs in aquatic systems have caused endocrine disruption. In this study we measured APs in the wastewater influent and effluent samples, from the urban, rural, livestock, commercial and hospital wastewater treatment plants (WWTPs) in Iran. Dispersive liquid–liquid microextraction (DLLME) combined with gas chromatography–mass spectrometry (GC–MS) was used for the extraction and determination of 4-NP and 4- t -OP. In these treatment plants, various processes such as activated sludge, aerated lagoon, moving bed biofilm reactor and activated sludge along with wetland were applied. The highest concentration of 4-NP and 4- t -OP was observed in commercial and livestock sewages. The activated sludge along with wetland and then the MBBR process showed the highest removal rates of pollutants. The rates of biodegradability and accumulation in sludge were determined and also the specific adsorption coefficient K d and the organic carbon–water partition coefficient k OC of the sludge for APs were calculated.

Simultaneous determination of seven multiclass veterinary antibiotics in surface water samples in the Republic of Korea using liquid chromatography with tandem mass spectrometry

A simultaneous determination method using solid-phase extraction and liquid chromatography with tandem mass spectrometry was developed to detect and quantify the presence of seven multiclass veterinary antibiotics (13 compounds in total) in surface water samples, which included the effluents of livestock wastewater and sewage treatment plants, as well as the reservoir drainage areas from dense animal farms. The pH of all water samples was adjusted to 2 or 6 before solid-phase extraction using Oasis HLB cartridges. The developed method was fully validated in terms of linearity, method detection limit, method quantitation limit, accuracy, and precision. The linearity of all tested drugs was good, with R2 determination coefficients ≥ 0.9931. The method detection limits and method quantitation limits were 0.1-74.3 and 0.5-236.6ng/L, respectively. Accuracy and precision values were 71-120 and 1-17%, respectively. The determination method was successfully applied for monitoring water samples obtained from the Yeongsan River in 2015. The most frequently detected antibiotics were lincomycin (96%), sulfamethazine (90%), sulfamethoxazole (88%), and sulfathiazole (50%); the maximum concentrations of which were 398.9, 1151.3, 533.1, and 307.4ng/L, respectively. Overall, the greatest numbers and concentrations of detected antibiotics were found in samples from the effluents of livestock wastewater, sewage treatment plants, and reservoir drainage areas. Diverse veterinary antibiotics were present, and their presence was dependent upon the commercial sales and environmental properties of the analytes, the geographical positions of the sampling points, and the origin of the water.

Determination and characterization of pharmaceuticals in sludge from municipal and livestock wastewater treatment plants

This study investigated 24 pharmaceuticals compounds belonging to the classes of analgesics, stimulants, anti-seizures, non-steroidal anti-inflammatory drugs (NSAIDs), and antibiotics in the sludge of 12 municipal sewage treatment plants (S-sludge) and 4 livestock wastewater treatment plants (L-sludge) located across Korea. Over 70% of the target compounds were detected in at least one sample of S-sludge and L-sludge. The total concentration of the target pharmaceutical compounds detected in S-sludge was 2.622–422.8 mg kg−1and the most dominant compound was acetylsalicylic acid (ASA: 0.374–367.0 mg kg−1) whereas in L-sludge, the total concentration was 43.87–156.8 mg kg−1and the most abundant compound was oxytetracycline (OTC: 34.54–86.39 mg kg−1). Cluster analysis revealed two distinct groups: group A, which were S-sludge samples including ASA, carbamazepine (CBM), and others, and group B were L-sludge samples, dominated by antibiotics (CTC, OTC, LIN). The total daily load amount of the target pharmaceuticals in S-sludge was 0.010–268.9 kg day−1 while the L-sludge was 0.021–0.529 kg day−1. The estimated amounts of the target pharmaceutical discharged from S-sludge and L-sludge into the Korean environment were 150.2 ± 47.94 ton yr−1 and 15.05 ± 5.671 ton yr−1 respectively, but the discharged amount of antibiotics from S-sludge (6.945 ton yr−1) was lower than that from L-sludge (9.234 ton yr−1).

생물학적 축산분뇨처리시설에서 인 회수의 가능성 평가

생물학적 축산분뇨처리시설에서 인 회수의 가능성 평가

Adaptability comparison of E. fetida in vermicomposting against sludge from livestock wastewater treatment plant based on their several growth stages.

Vermicomposting is a low-cost, eco-efficient process to deal with organic wastes. Mixtures of swine manure (SM), cow dung (CD), and animal wastewater treatment plant sludge (S) were applied as feeds, and Eisenia fetida was employed in this study to investigate the vermicomposting efficiency based on their several growth stages. The hatching test resulted in a 100% hatching rate in S60SM40 (60% S + 40% SM) mixture, while 4.40 hatchlings per cocoon were observed. The growth of infancy performed best in 0-20% CD mixtures (0.05 ± 0.002g), followed by in SM + CD (0.04 ± 0.003g). The highest growth rate of young and adult E. fetida was noticed in CD + S mixtures (11.14 ± 0.01 and 6.00 ± 0.02mg/d/worm, respectively), while the higher cocoon production of adults was noticed in S + SM mixtures especially in S40SM60 (537 ± 5 worms). Moreover, the conversion of solids; the modified pH value; the reduction in total organic carbon (TOC); total Kjeldahl nitrogen (TKN), NH4-N, NO3-N, and C:N ratio; and the rich in total available phosphorus (TAP) and total potassium (TK) content by young and adult E. fetida were related to the growth of worms. Such work would benefit understanding and to increase the efficiency of vermicompost processing of different wastes.