Piggery Waste Treatment Research Articles

Treatment of piggery waste in an ectopic microbial fermentation system and safety evaluation of generated organic fertilizer

AbstractBACKGROUNDWith the development of China’s livestock breeding industry, a large amount of waste was discharged and the local environment was seriously polluted. In this research, treatment performance of piggery waste in an ectopic fermentation system (EFS) using different padding materials and safety evaluation of generated organic fertilizer were studied in a pilot experiment.RESULTSDuring the whole fermentation process, temperature in the EFS fluctuated with addition of fresh feces and its consumption, and the pH value varied between 6.5 and 9.5. The absorption coefficient of pig breeding wastewater and feces per kilogram of padding (maize straw) at the end was 2.52 and 1.88, respectively. Bacteria played a major role in decomposing organic matter, and its number was basically maintained at 107–108 orders of magnitude. The C:N ratio in two EFS beds decreased gradually and was below 14:1 at the end, indicating the maturity of fermentation. Moreover, operation of the EFS with addition of rice husk/coconut shell mixture was more stable than that of EFS with maize straw. After fermentation, the heavy metal, total nutrient content, ascaris egg mortality and fecal coliform population of the generated organic fertilizer from two fermentation beds all met the limits of the Organic Fertilizer Standard of China, and the seed germination index of the product increased.CONCLUSIONSEFS employing maize straw or rice husk/coconut shell mixture as padding material can be used to treat both solid and liquid waste from pig farms. EFS technology reduced the biotoxicity of piggery waste. © 2022 Society of Chemical Industry (SCI).

Optimization of waste stabilization pond performance for piggery waste treatment using response surface methodology

The treatment of piggery wastewater using the waste stabilisation pond was studied in a semi- continuous process. Optimization of Chemical Oxygen Demand (COD) removal was conducted using response surface methodology where pH, temperature and retention time were independent variables. The Box-Behnken design approach, an experimental design was used for creating set of experimental runs needed for optimizing COD removal. An attempt was also made to optimize COD removal by reducing hydraulic retention time while maintaining pH and temperature of a defined range. Analysis of variance (ANOVA) was conducted on model terms and the results revealed that the coefficient of determination value (R2) of % COD removal was 0.86, 0.88, and 0.86 for the anaerobic, facultative and maturation pond respectively. Highest desirability was obtained for optimum COD % removal and this was 0.89, 0.89 and 1.0 for ponds.The waste stabilisation pond treatment process can effectively be improved on for piggery wastewater treatment.DOI: http://dx.doi.org/10.5755/j01.erem.73.2.17696

Effectiveness of piggery waste treatment using microbial fuel cells coupled with elutriated-phased acid fermentation

The present study evaluates the feasibility of increased power generation in microbial fuel cells (MFCs) coupled with acid elutriation fermentation. Raw piggery waste (RPW) and acid elutriation effluents (AEE) of piggery waste were used to generate bioelectricity in single-chambered air–cathode MFCs. RPW-fed MFCs exhibited stable performance after 12-days of operation, generating 540mV of open circuit voltage (OCV). RPW fed-MFCs displayed peak potential and maximal power density (PDmax) of 0.364V and 192mW/m2 with 980Ω external resistance (Rext), respectively. AEE-fed MFCs documented 818mV of maximum OCV. Furthermore, the peak potential and PDmax of 0.329V and 1553mW/m2 were generated with 100Ω Rext, respectively. RPW and AEE-fed MFCs exhibited 84% and 93% substrate removal efficiency, respectively. These findings suggest that a two-stage process including acid elutriation reactor asa pre-fermentation and MFCs greatly enhances substrate removal and electricity generation from piggery waste.

Economical and technical efficiencies evaluation of full scale piggery wastewater treatment BNR plants

A method evaluating the economic efficiency of piggery waste treatment plant based on kinetics for nitrogen removal performances is executed in this study and five full scale plants were evaluated, monitored intensively during one year under steady-state conditions. The performance data from those surveyed plants were recalculated by first-order kinetic equation instead of the Monod's equation, and the nitrogen removal kinetics related with COD/TKN ratios. Two plants adapting two extreme strategies for pre treatment, 'excess phase separation', and 'minimum phase separation', were evaluated by the assessment of life cycle cost (LCC). Although the compared two plants use an opposite strategy to each other, similar evaluation results are deduced by nitrogen removal efficiencies and operational and construction costs. But the proportions of constituent elements are as different as two opposite strategies, so electrical and construction costs are inversely proportional to chemical costs and operational costs respectively.

Plankton biomass in secondary ponds treating piggery waste

This study aimed at analyzing the plankton biomass found in a piggery waste treatment system, composed of a high rate algal pond (HRAP), two maturation ponds (MP1, MP2) (System A) and a water hyacinth pond (WHP) (System B). The ponds were disposed in series and the study was performed for 32 weeks. The physicochemical variables monitored were: pH, temperature, dissolved oxygen, soluble chemical oxygen demand, nitrogen compounds and total phosphorus. The plankton biomass was identified at genus level and the ecology index was calculated so as to describe its development in the ponds. Results showed lower specific richness, which was associated to the mono-specific Chlorella sp population. The protozoa density was conversely proportional to the green algae density. The higher species diversity occurred in the WHP and MP2. The green algae presented high relative density (>97 %). The Jaccard index reached 100% if Chlorella sp and sometimes diatoms were found in the system's inlet and outlet. The productivity of algal biomass was lower than 10 gTSS/m²/d in the maturation ponds, which was maintained in the HRAP. The green algae coefficient of variation (CV) varied from 0 to 1.5 in the HRAP and WHP, but was constant at 0.9 to the 10th week in MP1 and around 0.5 during all the experimental period for MP2. For the chlorophyll a, this coefficient varied in all the ponds.

Effect of biologically mediated pH change on phosphorus removal in BNR system for piggery waste treatment

Since applicable amount of animal waste to farm land has been greatly reduced because of the nutrient overload, nitrogen and phosphorus removal from animal waste has received a great attention. This study was conducted to evaluate how phosphorus was removed during biological nutrient removal (BNR) from piggery waste using laboratory and full scale units operated at 25 to 40°C. The phosphorus removal was performed by chemical precipitation with struvite and hydroxyapatite (HAP), cellular formation, it is basically related with pH and organic and nitrogen loads resulting in influent COD/N ratios. The removal efficiencies increased from 50 to 90% as COD/N ratios increased to 6 to 7, but carbon was not limited beyond this ratio for denitrification resulting in a stable pH. Overall, about 70% of the phosphorus removal was due to the precipitates of struvite and/or HAP, and the remaining removal was due to the cellular P formation. Any significant temperature effect on phosphorus removal was not observed within the operating temperature. In order to maximize phosphorus removal in BNR system, additional anoxic stage must be furnished prior to discharge its final effluent after oxic stage.

Principal Components Analysis to Evaluate Secondary and Tertiary Ponds for Piggery Waste Treatment

Stabilization ponds have been used to treat piggery waste. In order to better understand the interactions among the variables and the factors governing the process of degradation in the ponds and to identify the predominant factors in every stage (pond) of the treatment system, the principal components analysis (PCA) was employed in this study. The work was performed in an experimental treatment system comprising a primary (an equalizer, a settling tank, and two anaerobic ponds), a secondary (a high rate algal pond), and a tertiary treatment step (two maturation ponds and one water hyacinth pond), in series. The PCA was applied for the secondary and the tertiary steps of the treatment. It was evident that in the high rate algal pond (HRAP), the main artificial factors were: nutrient removal, algae growth and stabilization process; in the first maturation pond (MP1), nutrient removal, aerobic conditions and organic matter concentration; in the second maturation pond (MP2), nutrient removal and algae growth; and in the water hyacinth pond (WHP), nutrient removal, temperature, and algae growth. The PCA showed the importance of the aerobic conditions associated with the efficient performance of the treatment system.

Piggery waste treatment by using down-flow anaerobic fixed bed reactors

A study of the role of the depth in the performance of laboratory-scale down-flow anaerobic fixed-bed reactors (DFAFBR) was carried out at different nominal hydraulic retention times (HRT N ) using piggery waste as substrate at different influent concentrations (2, 4, 6 and 8 g COD/L). The profiles of soluble chemical oxygen demand (COD) (SCOD), organic nitrogen (O.N.), ammonia nitrogen (A.N.), pH and electrical conductivity (E.C.) through the reactor depths showed an initial highly active zone, which was located around the first half of the reactor depth, and a second zone with a lower biological activity. It was found that the depth of the active zone decreased as the HRT N increased and that the slopes of the profiles obtained increased with the rise in the influent concentration. A hydraulic test showed an increase in the dispersion number when the HRT N increased. The reactors showed a hydraulic pattern between plug-flow and back-mix. The real values of HRT (Θ) also defined as real contact times were determined to be 0.7, 2.1, 3.4, 4.7, 6.4 and 8 days for values of HRT N of 1, 2, 3, 4, 5 and 6 days, respectively. It was found that the concentration of SCOD within the reactor decreased exponentially with the increase in the value of θ. Additionally, the influent concentration had a strong influence on the SCOD variation concentration, mainly at values of θ under 1.5 days, which corresponded to the first part of the reactors.

Stabilization Pond Systems: Cost Estimation for the Treatment of Piggery Waste

This work presents the results from monitoring the three pond systems for the treatment of piggery waste, carried out over 12 months, with the objective of determining operational design parameters to minimize the treatment system costs. The first system consisted of two anaerobic and one facultative pond, the second and third systems were constituted by two anaerobic, two facultative, and one maturation pond, on a pilot scale, arranged in series. The three-pond systems achieved an efficiency of 91% for the removal of total chemical oxygen demand (TCOD) and 87% for total Kjeldahl nitrogen (TKN). A mathematical model to minimize treatment costs for these wastes was developed, within economic concepts. A simulation of costs was made for a treatment system with a flow rate of 20 m3/day and an efficiency level of about 90% for TCOD and TKN removal. The costs were US$812.40 for earth, US$6,360.60 for construction, US$4,530.90 for lining, and US$6,760.70 for pond maintenance, resulting in a total cost of US$18,464.60 for this flow rate and a unitary cost of the order of US$1.30 per swine/year.

Evaluation of sludge from pond system for treatment of piggery wastes

Stabilization ponds used for the treatment of piggery wastes accumulate sludge over time, which is commonly used in agriculture. The objective of this study was to evaluate the agronomic potential of this kind of sludge. The samplings were collected in two different phases. The first in two anaerobic ponds (AP1 and AP2) and in one facultative pond with 5 transverse baffles and, the second in the same facultative pond with aeration. The removed sludge of AP1 and AP2 was characterized as rich sludge in volatile solids and with low stabilization, there was a great accumulation of the total phosphorus in the sludge of AP2. The facultative pond presented greater retention of nutrients in the sludge in relation to the anaerobic ponds. The annual accumulation of sludge was 13.3 cm/year in the AP1 and 6.70 cm/year in the AP2, while in the pond with aeration this was on the average of 0.5 cm/year, due to the aeration regime. The sludge can be used as a fertilizer in agriculture, if the chemical characteristics of the soil are taken into account so as to avoid the accumulation of nutrients and damage to plants.

RESEARCH PAPERS : REMOVAL EFFICIENCY OF THE POLLUTANTS BY MULTILAYERED METAL TREATED CARBON FILTER

A study of the treatment of piggery wastes using a multilayered metal-activated carbon system followed by carbon bed filtration was carried out at bench scale. From the physicochemical properties obtained from samples treated with aqueous solutions containing metallic ions such as Ag, Cu, Na, K and Mn, main inspections are subjected to isothem shape, pore distribution with micropore, SEM and EDX. Multilayered metal-activated carbons were contacted to waste water to inwestigate the simultaneous catalytic effect for the COD, BOD, T-N and T-P removal. From these removal performance was achieved. The high efficiency of the multilayered metal-activated carbon bed, satisfactory removal performance was achieved. The high efficiency of the multilayered metal-activated carbon bed was derermined by the properties of this material for trapping, catalytic effect and adsorption of organic solid particles.

Evaluation of a Laboratory and Full-Scale Microlage Pond for Tertiary Treatment of Piggery Wastes

Piggery wastes tertiary treatment in laboratory and full-scale microalgal ponds was evaluated. COD, BOD, inorganic nitrogen and orthophosphate removals of up to 57 %, 69 %, 79 % and 74 %, respectively, were obtained. The effect of the hydraulic retention time (HRT) on removal efficiencies followed an exponential relationship. COD, BOD and orthophosphate removal rate decreased with increased effluent concentration while the inorganic nitrogen removal rate increased with an increasing effluent substrate concentration at inorganic nitrogen concentration values lower than 0.07 g l-1. Values of maximum substrate removal rate, half rate constant, cell yield coefficient, endogenous constant and maximum specific growth rate were 7.1 ? 0.5 d-1, 0.21 ? 0.02 g l-1, 0.26 ? 0.01 g VSS g-1 COD, 0.012 ? 0.001 d-1 and 1.9 ? 0.9 d-1, respectively. At full-scale, effluent COD, BOD, MPN, inorganic nitrogen and orthophosphate decreased while pH and Chlorophyll a increased with the operation time. It was found that the use of the final effluent as drinking water did not affect pigs growth.

Anaerobic digestion elutriated phased treatment of piggery waste

The performance of a novel high-rate anaerobic process, the anaerobic digestion elutriated phased treatment (ADEPT) process, for treating a slurry-type piggery waste (55 g COD/L and 37 g TS/L) was investigated. The ADEPT process consists of an acid elutriation slurry reactor for hydrolysis and acidification, followed by an upflow anaerobic sludge bed reactor for methanification. This process provides stable and high system performance with short HRT (7.4 d) and better effluent quality (2 g SCOD/L and 0.68 g VSS/L) due to the alkaline pH condition for hydrolysis/acidification phase, high refractory solids removal and ammonia toxicity reduction. The optimum pH and HRT for hydrolysis/acidogenesis of the piggery waste were 9 and 5 days at both 35 degrees C and 55 degrees C conditions. The hydrolysis and acidification rate in the mesophilic reactor were 0.05 d(-1) and 0.11 d(-1), meaning that hydrolysis was a limiting step. SCOD production by the hydrolysis was about 0.26 g SCOD/g VS(fed) (3.6 g SCOD/g VS reduction). Methane production and content in the system were 0.3 L CH4/g VS(fed) (0.67 L CH4/g VS destroyed) and 80%, respectively, corresponding to 0.23 L CH4/g COD removal (@STP).

High strength nitrogen removal from nightsoil and piggery wastes

Nightsoil and piggery wastes generally present high strength organics and nitrogen. This study evaluated the nitrogen removal characteristics with the existing and modified nightsoil and piggery waste treatment plants. The existing conventional plants showed 20 to 40% nitrogen removal, but the modification with SBR or MLE process could remove effectively both nitrogen and organics with the minimum COD/TN and alkalinity/TN ratios of 6 and 3.6, respectively. Nitrite nitrification and denitrification rates obtainable at higher nitrogen loads were faster than the rates of nitrate nitrification and denitrification resulting in less reactor volume requirement. However, the higher nitrogen loads increased the organic loads resulting in the reactor temperature inhibiting nitrification. Thus, a combined treatment with anaerobic digestion with the adjustment of influent bypass rates was proposed to reduce the reactor temperature and the external carbon requirement. The biological treatment could discharge about 1,100 mg/L soluble COD and 50 mg/L soluble nitrogen, respectively.

Nitrogen removal characteristics analyzed with gas and microbial community in thermophilic aerobic digestion for piggery waste treatment

In order to characterize the nitrogen conversion characteristics in a thermophilic aerobic digestion (TAD) system, a laboratory study has been conducted with the analysis of effluent gas and microbial community in the sludge samples. The lab TAD system was operated with HRT of 3 days and 60 degrees C. Based on the nitrogen mass balance, it has been found that about 2/3 of the daily load of nitrogen was converted to the gaseous form of nitrogen whereas cellular transformation and unmetabolized nitrogen accounted for about 1/3. Among the gaseous nitrogen transformation, significant amount of influent nitrogen had been converted to N2 gas (29% of influent N) and N2O (9% of influent N). Ammonia conversion was only 28% of influent N. The detection of N2O gas is a clear indication of the biological nitrogen reduction process in the thermophilic aerobic digester. No conclusive evidence for the existence of aerobic deammonification has been found. The microbial community analysis showed that thermophilic bacteria such as Bacillus thermocloacae, Bacillus sp. and Clostridial groups dominated in this TAD reactor. The diverse microbial community in TAD sludge may play an important role in removing both strong organics and nitrogen from piggery waste.

A model for cost estimation of system for piggery wastes treatment ponds: a case study

This article presents the results from the monitoring of a system of ponds for the treatment of piggery wastes, carried out during a 20 months period, with the objective to determine design parameters for the optimization of the treatment system. A series composed of two anaerobic ponds, one facultative pond and one water hyacinth pond, gave an efficiency of 97% in the removal of BOD5, 93% for total phosphorus, 91% for total Kjeldahl nitrogen and a removal of 7 log units for fecal coliforms. A model of the optimization incurred in the treatment of these wastes was developed, within economic concepts.

Optimization of the treatment of piggery wastes in water hyacinth ponds

This work investigates the optimal management of water hyacinth ponds for the improvement of piggery waste treatment. The optimal harvesting strategy for the water hyacinth was studied using a single mathematical model. The water hyacinth optimal harvesting problem was formulated as an optimal control problem that was solved by application of Pontryagin's Maximum Principle. The optimization of the water hyacinth control in the pond indicates that the plant density should be reduced whenever it reaches half of the maximum capacity for growth. Two experimental systems were used to validate the mathematical model, one in real scale and the other in pilot scale. The results demonstrated the feasibility of the proposed harvesting strategy. For example, a comparison of the total nitrogen removal in the different pilot ponds confirmed the modeling results, in that the performance of the pond maintained with 50% water hyacinth cover was better than the others.

Treatment of piggery waste by anaerobic fixed bed reactor and zeolite bed filter in a tropical climate: a pilot scale study

A study of the treatment of piggery wastes using an anaerobic fixed bed reactor (AFBR) followed by a zeolite bed filtration (ZBF) was carried out at pilot scale and tropical climate conditions (temperatures between 18 and 32 °C) in Costa Rica. The pilot AFBR operated at two different average organic volumetric loading rates ( B v): 5.7 and 24.0 kg COD per m 3 day, which corresponded to flow-rates of 25 and 45 m 3/day. Changes of the influent concentration did not provoke process failure. The system was able to overcome the variation of the influent strength at a fixed hydraulic retention time. COD and BOD removal efficiencies of 73 and 77%, respectively, were achieved for the highest B v studied. Average total suspended and settleable solids removals of 63.0 and 68.1%, respectively, were achieved, the last one being virtually independent of the B v applied. The reactor also operated as an equalisation tank reducing the variation of the influent strength, which could be favourable for the post-treatment of the final anaerobic effluent.

Treatment of piggery wastes in waste stabilization ponds

The piggery industry produces high effluent loads. This is due to the high concentration of animals kept in a confined space, foods with high protein content that are not well assimilated by the animals, and poor on-farm water management. In this study, we present the characteristics, design, site selection, soil study, and the construction of a pilot pond system for a family farm located in a warm climate area. The design includes a solids sedimentation phase, an anaerobic pond, a facultative pond and three maturation ponds. Once the system had reached steady state, the organic and bacterial kinetic constants were determined for each pond. The control parameters were determined and the dissolved oxygen and removal efficiency profiles were obtained. The results indicate that the effluent from the second maturation pond complies with the Official Mexican Standard for reuse in agriculture ("1000 FC/100 ml).

Performance of a baffled facultative pond treating piggery wastes

This paper shows the performance of a baffled facultative pond for the treatment of piggery wastes. The full-scale system is composed of an equalizer, one decanter (DP), two anaerobic ponds (LA1 and LA2), one facultative pond (LF), with five baffles, and one maturation pond with water hyacinths (LAG). The studies were conducted over a 12 month period in the west region of Santa Catarina, Brazil. The system was supplied daily with a volume of 3 m3/day of farm wastes. A good performance of the treatment system was obtained with average removal efficiencies of 98% for chemical oxygen demand, 93% for total solids, 98% for total phosphorus, 92% for total nitrogen, 7 log units of faecal coliforms and 5 log units of total coliforms. The facultative pond performed well, removing 43% of the chemical oxygen demand, 47% of total nitrogen and 54% of total phosphorus. It was found that the first baffle in the facultative pond was mainly responsible for the efficiency of this pond, and compared with another study the introduction of the baffles improved the removal efficiency by 20% for total phosphorus.