Poultry Wastewater Research Articles

Influence of Microwave Radiation on Pollutant Removal and Biomethane Production Efficiency in Anaerobic Treatment of High-Load Poultry Wastewater

The growing consumption of poultry meat has spurred the development of meat-processing plants and an associated rise in wastewater generation. Anaerobic digestion is one of the preferred processes for treating such waste. The current push towards biogas upgrading and out-of-plant use necessitates new, competitive ways of heating digesters. One such alternative is to use electromagnetic microwave radiation (EMR). The aim of the study was to assessment how EMR used as a heat source impacts the anaerobic processing of high-load poultry slaughterhouse wastewater (H-LPSW) and its performance. Microwave heating (MWH) was found to boost the CH4 fraction in the biogas under mesophilic conditions (35 °C) as long as the organic load rate (OLR) was maintained within 1.0 kgCOD/dm3·d to 4.0 kgCOD/dm3·d. The best performing variant—EPM heating (55 °C), OLR = 3.0 kgCOD/dm3·d, HRT = 5 days—produced 70.4 ± 2.7% CH4. High COD and TOC removal, as well as the highest biogas yields, were achieved for loadings of 1.0 gCOD/dm3·d to 4.0 gCOD/dm3·d. Effluent from the EMR-heated reactors (1.0 gCOD/dm3·d) contained, on average, 0.30 ± 0.07 gO2/dm3 at 55 °C and 0.38 ± 0.10 gO2/dm3 at 35 °C. The corresponding COD removal rates were 97.8 ± 0.6% and 98.1 ± 0.4%, respectively. The 5.0 gCOD/dm3·d and 6.0 gCOD/dm3·d OLR variants showed incremental decreases in performance. Based on the polymerase chain reaction results of 16S rDNA analysis, diversity of bacterial communities were mostly determined by OLR, not way of heating.

Antimicrobial properties of heterojunction BiSnSbO6-ZnO composites in wastewater treatment.

BiSnSbO6-ZnO composite photocatalytic material with type II heterojunction structure was synthesized by a simple solid-phase sintering method, it was characterized by XRD, UV-vis, and PT methods. The photocatalytic antibacterial experiments were carried out under LED light irradiation. The experimental results showed that the photocatalytic antibacterial properties of BiSnSbO6-ZnO composites against bacteria and fungi were significantly stronger than those of single BiSnSbO6 and ZnO. Under light conditions, the antibacterial efficiencies of 500mg/L BiSnSbO6-ZnO composites against E. coli, S. aureus, and P. aeruginosa reached 99.63%, 100%, and 100% for 6h, 4h, and 4h, respectively. The best antibacterial concentration of BiSnSbO6-ZnO composite against the eukaryotic microorganism Candida albicans was 250mg/L, and the antibacterial efficiency reached the highest 63.8% at 6h. Antibacterial experiments were carried out on domestic livestock and poultry wastewater, which showed that the BiSnSbO6-ZnO composite photocatalytic material has broad-spectrum antibacterial activity against bacteria, and the antibacterial effect has species differences. Through the MTT experiment, it is proved that the prepared BiSnSbO6-ZnO composite photocatalytic material has no toxicity at the experimental concentration. According to the free radical scavenging experiment and SEM observation of the morphological changes of the bacteria after light treatment, the prepared BiSnSbO6-ZnO composite photocatalytic material can generate active species OH, h+, and e- through light irradiation to achieve the purpose of sterilization, where e- play a major role, indicating that the BiSnSbO6-ZnO composite photocatalytic material has broad application prospects in the actual antibacterial field.

Application of Green Technology to Extract Clean and Safe Bioactive Compounds from Tetradesmus obliquus Biomass Grown in Poultry Wastewater.

Microalgae are capable of assimilating nutrients from wastewater (WW), producing clean water and biomass rich in bioactive compounds that need to be recovered from inside the microalgal cell. This work investigated subcritical water (SW) extraction to collect high-value compounds from the microalga Tetradesmus obliquus after treating poultry WW. The treatment efficiency was evaluated in terms of total Kjeldahl nitrogen (TKN), phosphate, chemical oxygen demand (COD) and metals. T. obliquus was able to remove 77% TKN, 50% phosphate, 84% COD, and metals (48-89%) within legislation values. SW extraction was performed at 170 °C and 30 bar for 10 min. SW allowed the extraction of total phenols (1.073 mg GAE/mL extract) and total flavonoids (0.111 mg CAT/mL extract) with high antioxidant activity (IC50 value, 7.18 µg/mL). The microalga was shown to be a source of organic compounds of commercial value (e.g., squalene). Finally, the SW conditions allowed the removal of pathogens and metals in the extracts and residues to values in accordance with legislation, assuring their safety for feed or agriculture applications.

Removal of Antibiotic Resistance Genes from Animal Wastewater by Ecological Treatment Technology Based on Plant Absorption.

With the aim of controlling the pollution of antibiotic resistance genes (ARGs) in livestock and poultry wastewater, this paper highlights an ecological treatment technology based on plant absorption and comprehensively discusses the removal effect, driving factors, removal mechanism, and distribution characteristics of ARGs in plant tissues. The review shows that ecological treatment technology based on plant absorption has gradually become an important method of wastewater treatment of livestock and poultry breeding and has a good ARG removal effect. In plant treatment ecosystems, microbial community structure is the main driver of ARGs, while mobile genetic elements, other pollutants, and environmental factors also affect the growth and decline of ARGs. The role of plant uptake and adsorption of matrix particles, which provide attachment sites for microorganisms and contaminants, cannot be ignored. The distribution characteristics of ARGs in different plant tissues were clarified and their transfer mechanism was determined. In conclusion, the main driving factors affecting ARGs in the ecological treatment technology of plant absorption should be grasped, and the removal mechanism of ARGs by root adsorption, rhizosphere microorganisms, and root exudates should be deeply explored, which will be the focus of future research.

Pomological and Olive Oil Quality Characteristics Evaluation under Short Time Irrigation of Olive Trees cv. Chemlali with Untreated Industrial Poultry Wastewater

The aim of this work was the investigation of the effect of wastewater generated from the poultry meat industry on the irrigation of olive trees, during a short time period, in order to evaluate its impact on pomological criteria and olive oil quality. Olive trees were subjected to irrigation with different water qualities: (i) poultry wastewater (PWW), (ii) poultry wastewater diluted with tap water 50:50 (v/v) (PWTWW), (iii) rain-fed cultivation system (control). The results showed that PWTWW contains the optimal mineral proportions, leading to improved pomological criteria. However, the highest significant pulp oil content was obtained using poultry wastewater irrigation (69.51%), while this was 66.71% using diluted poultry wastewater, and 58.03 % for the control. Poultry wastewater irrigation yielded the best results in oil standard quality indices. In addition, an enrichment in oil total polyphenols content was achieved. The oil fatty acid profile was not affected following irrigation with poultry wastewater. Nevertheless, there was a significant increase in the contents of oleic acid and alcohols, accompanied by a decrease in total sterols. However, heavy metals accumulation was observed in both fruits and olive oil. In conclusion, our results suggest that among the three water qualities, poultry wastewater is the best alternative to improve olive oil quality.

The Synergistic Effect of Simultaneous Ultrasound Heating and Disintegration on the Technological Efficiency and Energetic Balance of Anaerobic Digestion of High-Load Slaughter Poultry Sewage

Regulations in force urge for thermal pre-treatment of post-slaughter waste prior to its anaerobic digestion. Increased interest in biomethane as a fuel in gas networks or vehicles of road transport forces the need to look for heating methods that are alternative to heat recovery from cogeneration. The goal of this study was to determine the synergistic effect of simultaneous ultrasound heating and disintegration on the technological efficiency and energetic balance of the anaerobic digestion of high-load slaughter poultry wastewater. The highest efficiency of anaerobic digestion was obtained for the ultrasound thermal pre-treatment (60 min, 90 °C, OLR = 2.0 gCOD/dm3). In this experimental variant, the biogas production rate reached 9.0 ± 0.2 cm3/gCOD·h, biogas yield was 492 ± 10 cm3/gCOD, and the biogas produced contained 69.8 ± 1.4% CH4. Given the incurred energy outputs, the highest net energetic efficiencies, i.e., 5.92 ± 0.43 Wh and 5.80 ± 0.42 Wh, were obtained in the variants with the conventional thermal pre-treatment (60 min, 70 °C, OLR = 6.0 gCOD/dm3) and ultrasound thermal pre-treatment (60 min, 70 °C, OLR = 6.0 gCOD/dm3), respectively.

Occurrence of Staphylococcus spp. in the wastewaters from Iran: Diversity, antimicrobial resistance, and virulence potential

Abstract The prevalence, antibiotic resistance, and virulence characteristics of Staphylococci from hospitals, livestock, municipals, and poultry wastewaters were investigated in Ardabil, Iran. From 155 staphylococcal isolates, 44.5% were coagulase-positive Staphylococcus (CoPS) and 55.5% were coagulase-negative Staphylococcus (CoNS) spp. Both CoPS and CoNS species were mainly found in hospital and poultry wastewater samples. The most prominent CoPS and CoNS species were Staphylococcus aureus at 80% and Staphylococcus xylosus at 37%. Methicillin resistance was found in 2% of S. aureus isolates. Overall, 49.2% of CoPS and 47.6% of CoNS isolates exhibited multidrug resistance phenotypes. CoPS isolates were the most resistant to penicillin (89%) and erythromycin (62%) and CoNS isolates exhibited the highest resistance to erythromycin (55%) and tetracycline (49%). Inducible clindamycin resistance was detected in 11% of S. aureus isolates. The ermC and aac genes were detected as the most common macrolide–lincosamide–streptogramin B and aminoglycoside-resistance encoding genes in 82.5 and 22.5% of S. aureus isolates, respectively. Most of the S. aureus isolates were positive for multiple virulence factors. The methicillin-resistant S. aureus isolates belonged to SCCmec type V. A new spa type t19215 was also identified. The occurrence of multidrug-resistant S. aureus with diverse genetic resistance and virulence background in wastewater is of great health concern.

Water quality assessment and pollution source apportionment using multivariate statistical techniques: a case study of the Laixi River Basin, China.

Identifying potential sources of pollution in tributaries and determining their contribution rates are critical to the treatment of water pollution in main streams. In this paper, we conducted a multivariate statistical analysis on the water quality data of 12 parameters for 3years (2018-2020) at six sampling sites in the Laixi River to qualitatively identify potential pollution sources and quantitatively calculate the contribution rates to reveal the tributaries' pollution status. Spatio-temporal cluster analysis (CA) divided 12months into two parts, corresponding to the lightly polluted season (LPS) and highly polluted season (HPS), and six sampling sites were divided into two regions, corresponding to the lightly polluted region (LPR) and highly polluted region (HPR). Principal component analysis (PCA) was used to determine the potential sources of contamination, identifying four and three potential factors in the LPS and HPS, respectively. The absolute principal component score-multiple linear regression (APCS-MLR) receptor model quantitatively analyzed the contribution rates of identified pollution sources, and the importance of the different pollution sources in LPS can be ranked as domestic sewage and industrial wastewater and breeding pollution (33.80%) > soil weathering (29.02%) > agricultural activities (20.95%) > natural influence (13.03%). HPS can be classified as agricultural cultivation (41.23%), domestic sewage and industrial wastewater and animal waste (33.19%), and natural variations (21.43%). Four potential sources were identified in LPR ranked as rural domestic sewage (31.01%) > agricultural pollution (26.82%) > industrial effluents and free-range livestock and poultry pollution (25.13%) > natural influence (14.82%). Three identified latent pollution sources in HPR were municipal sewage and industrial effluents (37.96%) > agricultural nonpoint sources and livestock and poultry wastewater (33.55%) > natural sources (25.23%). Using multivariate statistical tools to identify and quantify potential pollution sources, managers may be able to enhance water quality in tributary watersheds and develop future management plans.

Evaluating the effectiveness of filter media in the treatment of poultry wastewater

Evaluating the effectiveness of filter media in the treatment of poultry wastewater

Treatment of Poultry Wastewater with Tannin as a Natural Coagulation Agent

The coagulation-flocculation process frequently employs chemical-based coagulants and flocculants. The disadvantages of utilizing these chemical substances have triggered researchers to investigate natural substances to replace or reduce the number of chemical-based coagulants and flocculants. Thus, this study investigates the potential use of tannin as a natural coagulant for slaughterhouse wastewater treatment. Results indicated that a pH of 6.9 and a dosage of 2mL of tannin resulted in the higher removal of different pollutants from slaughterhouse wastewater. Tannin was able to perform excellent elimination efficiency for all parameters under these ideal conditions. Turbidity, COD, colour, and TSS all had removal efficiencies of 93.7%, 76.2%, 95.7%, and 88.9%, respectively. Results were compared to alum, which was used as a coagulant, and it was found that pH 6.9 and dosage of 5mL were the optimum conditions for alum in slaughterhouse wastewater treatment. Alum achieved 92.8% for turbidity, 75.4% for COD, 93.1% for colour, and 91.7% for TSS, respectively. In contrast to alum, tannin is a natural substance that produces a small quantity of sludge while being safe for the environment and non-toxic. The tannin coagulant has the potential to be an efficient and productive coagulant agent for wastewater treatment from slaughterhouses.

Role of Electrochemically Active Bacteria in the Treatment of Piggery and Poultry Wastewaters from Umuagwo in Ohaji Egbema Local Government Area of Imo State, Nigeria

In this study, piggery and poultry wastewaters were used as agro-based industrial wastewaters to evaluate the role of electrochemically active bacteria in an anodic chamber of microbial fuel cell (MFC) with 0.1M potassium permanganate cathodic cell using salt bridge preparation. The BOD5, COD, TDS, TSS, nitrogen, phosphates, pH and conductivity served as indicative parameters for determining the wastewater treatment efficiencies (WWTE) of the MFCs. Results obtained from the WWTE reveal that the MFCs were able to reduce the piggery wastewater parameters, BOD, COD, TDS, TSS, nitrogen, phosphate, pH, conductivity by 89.66, 69.57, 52.20, 69.04, 70.27, 59.57, - 4.41 and 0.99 %, respectively while the same parameters for the poultry wastewater were reduced by 82.61, 78.59, 58.03, 67.13, 70.49, 64.52, 2.70 and 28.04 %, respectively. Statistically, there were significant differences before and after treatments and between wastewater samples revealing that that the effect of treatment before and after on physicochemical parameters were different for piggery wastewater than they were for poultry wastewater. Microbes in the biofilms on the electrodes (potential exoelectrogens) include Staphylococcus aureus, Bacillus cereus, Micrococcus luteus, Corynebacterium sp., Enterococcus sp., Pseudomonas aeruginosa, Escherichia coli, Klebsiella sp., Salmonella sp. and Shigella sp. while the fungal isolates include Mucor sp., Saccharomyces sp. and Aspergillus sp. in both piggery and poultry wastewaters. Thus, microbial fuel cell bacteria oxidize the organic matter leading to decontamination of the wastewater – a significant approach in addressing the public health threats of these wastes in our country.

Microalgal treatment of high-nutrient wastewater using twin layer cultivation system

High-nutrient wastewater such as solid waste leachate, anaerobic digestate, and poultry wastewater has high turbidity, dark color, and high concentration of nutrients. Therefore, it cannot be treated using microalgae directly and needs to be diluted prior to treatment. This study assessed the potential of Tetradesmus obliquus for the treatment of high-nutrient wastewater using a twin-layer cultivation system. Prior to microalgal treatment of high-nutrient wastewater, it was diluted by wetland treated municipal wastewater. Results showed Tetradesmus obliquus can efficiently treat and grow in all types of diluted high-nutrient wastewater using a twin-layer cultivation system. However, microalgae cultivated in poultry wastewater gave the highest average biomass productivity and carbon capture rate of 5.13 and 2.51 g m−2 d−1 respectively. Maximum nutrient removal rate of 6.15, 7.64, and 0.69 mg L−1 d−1 for NH4+-N, TKN, and PO4−3-P were achieved from poultry wastewater. In contrast, the highest lipid content of 30.3% was observed in microalgae cultivated in municipal wastewater due to its low nitrogen content. Thus, successful microalgal treatment of different high-nutrient wastewater can be performed through its prior dilution.

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.

Effect of chromium and copper stress on antibiotic resistance genes transfer and associated metabolic mechanism in electrochemical system treating sulfanilamide wastewater

To investigate the electrochemical process and metabolic mechanism of sulfonamide wastewater treatment under chromium and copper stress in bioelectrochemical system, electron transfer and antibiotic resistance genes (ARGs) transfer were investigated. Metagenomics was used to reveal metabolic pathways, antibiotic resistance mechanisms, carbohydrate active enzymes, etc. The results indicated that copper stress not only did not affect the electricity production performance of the electrochemical system, but also promoted the electron transfer efficiency. Copper stress can also effectively control ARGs and mobile genetic elements (MGEs). The metagenomics analysis showed that Cu increased the abundance of coxA and cox1 genes in the electrochemical system and increased the C-type cytochrome, thereby improving the ability of electron transfer. In contrast, chromium stress affected electrochemical system performance and accelerated ARGs transfer, and increasing the risk of resistance gene horizontal transfer. The mechanism of antibiotic resistance was mainly through the efflux function of antibiotics (61.5%), which was mainly related to Proteobacteria (51.5%) and Firmicutes (25.4%). The results also indicated that the glycolysis process was promoted by Cu, while the process was negatively affected by Cr. This study revealed the effect of chromium and copper stress on the metabolic mechanisms of microorganisms in bioelectrochemical system at the genetic level and provided a theoretical basis for risk control of livestock and poultry wastewater.

La(III) loaded Fe(III) cross–linked chitosan composites for efficient removal of phosphate from wastewater: Performance and mechanisms

The cost–effective removal and recovery of phosphate from wastewater is of great importance to controlling eutrophication and alleviating the phosphorus resource exhaustion crisis. Herein, chitosan (Cs) encapsulated bimetallic lanthanum (La) and iron (Fe) metal(hydro) oxides (La/Fe–Cs) composites were fabricated using a co–precipitated method for enhanced phosphate removal and recovery. The La/Fe–Cs composites had rough and raised spongy–like surfaces coated with La/Fe (hydr)oxide particles with a high specific surface area of 109.84 m2 g−1, providing more potential binding sites for phosphate capture. The La/Fe–Cs composites with a 1:2 La–to–Fe molar ratio exhibited a maximum adsorption capacity of 67.52 mg g−1 for phosphate at 308 K, calculated using the Langmuir model, which was 211% higher than that of monometallic Fe–Cs composites. Meanwhile, this composite also showed a high phosphate removal rate (63–95%) in an extensive applicable pH range (3.00–10.00) and rapid adsorption within 10 min (up to 94%). Moreover, the adsorption of phosphate by La/Fe–Cs composites was mildly disturbed against co–existing ions of NO3−, Cl−, and humic acid, while adsorption capacities were reduced by almost 13–45% with the existence of SO42−, HCO3−, and CO32−. The FTIR, XPS, and DFT results suggested that La–doped facilitated phosphate removal and the predominant mechanisms involved electrostatic interaction, surface precipitation, and inner–sphere complexation processes. Additionally, La/Fe–Cs composites also illustrated excellent efficiencies in simultaneous scavenging phosphate and ammonia from eutrophication and poultry wastewater. These results highlight bimetallic La/Fe–Cs composites are promising candidates for efficient elimination and recovery of phosphate from real wastewater, and subsequently could be used as slow–release fertilizers or soil amendments.

Deciphering chloramphenicol biotransformation mechanisms and microbial interactions via integrated multi-omics and cultivation-dependent approaches

BackgroundAs a widely used broad-spectrum antibiotic, chloramphenicol is prone to be released into environments, thus resulting in the disturbance of ecosystem stability as well as the emergence of antibiotic resistance genes. Microbes play a vital role in the decomposition of chloramphenicol in the environment, and the biotransformation processes are especially dependent on synergistic interactions and metabolite exchanges among microbes. Herein, the comprehensive chloramphenicol biotransformation pathway, key metabolic enzymes, and interspecies interactions in an activated sludge-enriched consortium were elucidated using integrated multi-omics and cultivation-based approaches.ResultsThe initial biotransformation steps were the oxidization at the C1-OH and C3-OH groups, the isomerization at C2, and the acetylation at C3-OH of chloramphenicol. Among them, the isomerization is an entirely new biotransformation pathway of chloramphenicol discovered for the first time. Furthermore, we identified a novel glucose-methanol-choline oxidoreductase responsible for the oxidization of the C3-OH group in Sphingomonas sp. and Caballeronia sp. Moreover, the subsequent biotransformation steps, corresponding catalyzing enzymes, and the microbial players responsible for each step were deciphered. Synergistic interactions between Sphingomonas sp. and Caballeronia sp. or Cupriavidus sp. significantly promoted chloramphenicol mineralization, and the substrate exchange interaction network occurred actively among key microbes.ConclusionThis study provides desirable strain and enzyme resources for enhanced bioremediation of chloramphenicol-contaminated hotspot sites such as pharmaceutical wastewater and livestock and poultry wastewater. The in-depth understanding of the chloramphenicol biotransformation mechanisms and microbial interactions will not only guide the bioremediation of organic pollutants but also provide valuable knowledge for environmental microbiology and biotechnological exploitation.ATrkAsjN2DD8FKaZQAS4KPVideo

Red Mud as Adsorbent to Recover Phosphorous from Wastewater Streams

Background: Phosphorous (P) is an essential nutrient with finite and non-renewable resources; however, it can cause eutrophication in freshwater. The use or storage of red mud (RM), a by-product of alumina production with high iron and aluminium content, poses another environmental issue. Objective: This paper examines the possibility of P recovery from various wastewaters and landfill leachate with RM. Methods: Pulverized, on-site pre-treated red mud was used. Synthetic P solution, poultry wastewater effluent, the spiked effluent of a municipal wastewater treatment plant and landfill leachate were examined. Results and conclusions: Removal efficiencies of 0.41–1.24 mg P/mg RM for the wastewater effluents and 0.10–0.13 mg P/g RM for the leachate resulted in a decreased phosphorous concentration (0.02–0.57 mg P/L) for each liquid. Despite the doses being substantially higher than the stoichiometric value (103 mg P/g RM), the dosage increase did not result in a considerable cost increase. Further investigation is in progress to insert this solution into existing wastewater treatment technologies to facilitate excellent effluent quality and utilize the nutrient content of red mud.

Health Risk Assessment of Heavy Metals in Shallow Groundwater of Coal-Poultry Farming Districts.

This study aimed to assess the heavy metal (Mn, Ni, Cu, Zn, Sr, Cd, Pb, and Cr) pollution characteristics, sources, and human health risks in shallow groundwater in the impact zones of urban and rural semi-intensive poultry farms in Suzhou City. Ordinary kriging interpolation showed that poultry farming contributed substantially to the pollution of shallow groundwater by Mn, Zn, and Cu. Positive matrix factorization was applied to identify the sources of heavy metals, and the health risks were assessed based on the hazard index and carcinogenic risks of the various sources. Heavy metal enrichment was closely related to anthropogenic activities. In addition, four sources were identified: poultry manure (29.33%), natural source (27.94%), industrial activities (22.29%), and poultry wastewater (20.48%). The main exposure route of carcinogenic and non-carcinogenic risks to adults and children was oral ingestion. The non-carcinogenic risk of oral ingestion in children was higher than that in adults; the carcinogenic risk was higher in adults than in children. Poultry manure (42.0%) was considered the largest contributor to non-carcinogenic risk, followed by poultry wastewater (21%), industrial activities (20%), and natural sources (17%). Industrial activity (44%) was the primary contributor to carcinogenic risk, followed by poultry wastewater (25%), poultry manure (19%), and natural sources (12%).

Assessment of Bacterial Diversity of Industrial Poultry Wastewater by Denaturing Gradient Gel Electrophoresis (DGGE) and the Cultivation Method in Order to Inform Its Reuse in Agriculture.

Effluents discharged by poultry meat industries are heavily polluted with raw materials, such as fat, blood residues, and proteins. Thus, untreated effluents directly discharged into the environment may constitute a public health threat. This study aims to evaluate the bacterial diversity of three water qualities: industrial poultry wastewater (PWW), tap water (TW), and PWW diluted with TW (50 : 50) (V/V) (TWPWW) by the combination of culture-independent and culture-dependent approaches. The total bacterial DNA was extracted using phenol/chloroform method. The hypervariable 16S rRNA region V3-V5 was amplified by PCR using universal primers. The amplicons were separated by vertical electrophoresis on a polyacrylamide gel of increasing denaturing gradient according to their richness in GC bases. Selected bands were reamplified and sequenced. Pure isolated bacteria from nutrient agar medium were characterized according to their morphological and biochemical characteristics. Genomic DNA from pure strains was extracted by boiling method, and a molecular amplification of the 16S–23S ITS region of the 16S rRNA gene was performed using the universal primers. Selected isolates were identified by sequencing. Results showed a high bacterial load and diversity in PWW in comparison with TW and TWPWW. A collection of 44 strains was obtained, and 25 of them were identified by sequencing. Proteobacteria represented 76% of isolated bacteria Gamma-Proteobacteria was the predominate isolate (68%). Other isolates were Firmicutes (8%), Bacteroidetes (12%), and Actinobacteria (8%). These isolates belong to different genera, namely, Pseudomonas, Acinetobacter, Proteus, Empedobacter, Corynebacterium, Enterobacter, Comamonas, Frondibacter, Leclercia, Staphylococcus, Atlantibacter, Klebsiella, and Microbacterium.

Enhancement of nutrients removal and biomass accumulation of algal-bacterial symbiosis system by optimizing the concentration and type of carbon source in the treatment of swine digestion effluent

The algae-bacteria symbiosis system (ABS) is used to effectively solve the problems of low carbon/nitrogen (C/N) ratio, low biodegradability and high ammonia toxicity in swine digestion effluent. This study examined the effects of the concentration and type of carbon source on ABS in the pollutants removal especially ammonia. When C/N ratio was 30:1 and carbon source was sodium acetate, the ABS was most conducive to the removal of nitrogen, phosphorus and COD, and to the accumulation of biomass and lipids. To make the wastewater discharge meet the relevant standard, the ABS + mono-cultivation of algae reprocessing system (MAS), was applied to actual swine digestion effluent. Through adjusting the C/N ratio in ABS to 30:1, the biomass concentration was 2.06 times higher than that of raw wastewater, and the removal efficiencies of NH4+-N, TN, TP and COD increased by 1.43, 1.46, 1.95 and 1.28 times, respectively. The final concentrations of NH4+-N, TN, TP and COD after the treatment of ABS (C/N ratio of 30:1) + MAS, were 16.98 ± 1.07 mg L−1, 18.72 ± 1.81 mg L−1, 0.48 ± 0.01 mg L−1 and 263.49 ± 11.89 mg L−1, respectively, reached the Chinese discharge standards for livestock and poultry wastewater. Bacterial community analysis showed that the dominant species of the ABS (C/N ratio of 30:1) was Corynebacterium (genus level). This study revealed that adjusting the concentration and type of carbon source was helpful to the nutrient cycling and resource utilization of ABS, indicating a feasible technique for treating high ammonia nitrogen digestate.