Microalgal system for treatment of effluent from poultry litter anaerobic digestion

The potential of mixotrophic microalgae to utilize poultry litter anaerobic digester (AD) effluent (PLDE) as nutritional growth medium was evaluated. Three algal strains viz. Chlorella minutissima, Chlorella sorokiniana and Scenedesmus bijuga and their consortium showed significant biomass productivity in 6% (v/v) concentration of PLDE in deionized water. Multiple booster dosage of PLDE supported better growth relative to a single dose PLDE. The maximum biomass productivity of 76 mg L⁻¹ d⁻¹ was recorded. The biomass was rich in protein (39% w/w) and carbohydrates (22%) while lipids (<10%) were low, making it most suitable as an animal feed supplement. The mixotrophic algae showed sustainable growth against variations in PLDE composition in different AD batches, thus proving to be a suitable candidate for large scale wastewater treatment with concomitant production of renewable biomass feedstock for animal feed and bioenergy applications.     

Impact on degradation of antibiotics from poultry litter using Autothermal Thermophilic Aerobic Digestion (ATAD)

Tetracycline (TC) is one of the common antibiotics which is widely used in livestock growth promotion. The prevalent application TC may pave way to progression of antibiotic resistant bacteria. The main objective of this study is to determine the effect of Autothermal Thermophilic Aerobic Digestion (ATAD) on the fate of TC residues found in digested poultry litter. For the determination of TC in poultry litter, thin layer chromatography (TLC) and high performance liquid chromatography (HPLC) were done. TLC result revealed that the R_f value of standard TC on TLC plate was 0.97 which correlates with the R_f value of TC at 0, 12, 24 and 36 h of digested poultry litter sample and not at 48, 60 and 72 h. HPLC chromatogram revealed that the limits of detection and the recovery were 5 µg/kg and 96% for standard TC. Linear correlation curves were obtained over the series of 100–500 µg/mL with correlation coefficient of 0.996 and the calibration curve was Y = 0.001X + 0.066. These results confirmed the degradation of TC in ATAD digestion of poultry litter by abiotic processes.     

Application of solid waste from anaerobic digestion of poultry litter in Agrocybe aegerita cultivation: mushroom production, lignocellulolytic enzymes activity and substrate utilization

The degradation and utilization of solid waste (SW) from anaerobic digestion of poultry litter by Agrocybe aegerita was evaluated through mushroom production, loss of organic matter (LOM), lignocellulolytic enzymes activity, lignocellulose degradation and mushroom nutrients content. Among the substrate combinations (SCs) tested, substrates composed of 10–20% SW, 70–80% wheat straw and 10% millet was found to produce the highest mushroom yield (770.5 and 642.9 g per 1.5 kg of substrate). LOM in all SCs tested varied between 8.8 and 48.2%. A. aegerita appears to degrade macromolecule components (0.6–21.8% lignin, 33.1–55.2% cellulose and 14–53.9% hemicellulose) during cultivation on the different SCs. Among the seven extracellular enzymes monitored, laccase, peroxidase and CMCase activities were higher before fruiting; while xylanase showed higher activities after fruiting. A source of carbohydrates (e.g., millet) in the substrate is needed in order to obtain yield and biological efficiency comparable to other commercially cultivated exotic mushrooms.     

Properties of poultry litter humic acid fractions and their metal-complexes

Summary Molecularly homogenous fractions of humic acid extracted from poultry litter were characterized by elemental and functional group analysis, molecular weight determination, U.V. and infrared spectroscopy. The divalent and trivalent metal complexes prepared from different fractions of humic acid were characterized by infrared spectroscopy. The molecular weight of molecularly homogenous fractions of poultry litter humic acid ranged from 2545 to 40219. High amounts of functional groups in low molecular weight of humic acid fraction has been indicated by infrared spectra and by chemical analysis. The presence of chromophores C=C and C=O and auxochromes C−OH, C−NH were indicated by infrared and U.V. spectra of these humic acid fractions. Stable complex formation of Fe³⁺, Cu²⁺, and Zn²⁺ with −OH, −NH₂ and −COOH ligands of humic acid fractions involved electrovalent and coordinate-covalent bonds. Intensity of absorption bands of molecularly homogenous fractions of humic acid in I.R. spectra is differing depending upon the functional groups content of humic acid fractions. Journal paper No. 5. Department of Soil Science, R.A.U., T.C.A., Pusa-Dholi Campus, Dholi-843121, Muzaffarpur, Bihar, India.     

Effects of poultry litter on the chronic toxicity of cadmium to common carp (Cyprinus carpio)

Static 90 day bioassays were made in outdoor cement tanks (300 l capacity) with fries of common carp (Cyprinus carpio) exposed to 1.0, 2.5 and 5.0 mg/l of cadmium (Cd) treated individually and with 250 mg/l poultry litter. Addition of poultry litter significantly reduced the concentrations of dissolved Cd in water and whole body Cd in fish and plankton. In contrast, concentrations of total Cd in sediment increased under the influence of poultry litter. Cadmium showed a distinct partitioning pattern in the sediment. Addition of poultry litter did not change the partitioning pattern. Growth of fish, in respect to length and weight, was reduced by all levels of Cd exposure. In contrast, maximum weight gains, increased lengths, increased specific growth rates and yields were recorded under the influence of poultry litter alone. Addition of poultry litter reduced the ill effects on growth of fish produced by Cd and proved to be a promising tool to counter Cd pollution in aquaculture.     

The impact of corncob biochar and poultry litter on pepper (Capsicum annuum L.) growth and chemical properties of a silty-clay soil

Red pepper (Capsicum annuum L.) is one of the most commonly cultivated vegetable in the Mediterranean region. This study evaluated the effects of biochar derived from corncob and poultry litter on growth of red pepper (Capsicum annuum L.) and some chemical properties of a silty clay soil. The experiment consisted of two factors, i.e., biochar doses (0, 0.5, 1.0 and 2%) and poultry litter doses (0, 0.5, 1.0 and 2%). The number of days to 50% flowering, plant height, stem diameter, total number of leaves per plant, the number of main branches per plant, fresh root weight, root length, dry shoot weight, macro (P and K) and micro (Fe, Zn, Cu and Mn) nutrient concentrations of leaves were determined to compare the efficiency biochar and poultry litter. Moreover, post-harvest soil analysis was conducted to measure pH, organic matter, and macro and micronutrient contents. Biochar had varying impact on plant growth parameters, whereas poultry litter alone or in combination with biochar increased macro and micronutrient concentrations of soil and improved most of the growth parameters of red pepper. In contrast, sole biochar application had no significant impact on most of the growth parameters. Wider C/N ratio (107.7) of corncob derived biochar restricted the nitrogen supply for plant growth. The combination of 0.5% biochar and 2% poultry litter resulted in the highest plant height (36.7 cm) and stem diameter (0.69 cm). The results revealed that application of single biochar derived from corncob is insufficient to supply adequate nutrients for optimal plant growth. The application of biochar alone enhances carbon sequestration in soils, however most biochars like cornconb biochar do not contain sufficient available plant nutrients. Therefore, biochars should be applied along with mineral fertilizers or organic materials such as poultry manure which is rich in available plant nutrients.     

Improvement of the anaerobic treatment of potato processing wastewater in a UASB reactor by co-digestion with glycerol

The effect of three different types of glycerol on the performance of up-flow anaerobic sludge blanket (UASB) reactors treating potato processing wastewater was investigated. High COD removal efficiencies were obtained in both control and supplemented UASB reactors (around 85%). By adding 2 ml glycerol product per liter of raw wastewater, the biogas production could be increased by 0.74 l biogas ml⁻¹ glycerol product, which leads to energy values in the range of 810–1270 kWh_electric per m³ product. Moreover, a better in-reactor biomass yield was observed for the supplemented UASB reactor (0.012 g VSS g⁻¹ COD_removed) compared to the UASB control (0.002 g VSS g⁻¹ COD_removed), which suggests a positive effect of glycerol on the sludge blanket growth.     

Role of nickel in high rate methanol degradation in anaerobic granular sludge bioreactors

The effect of nickel deprivation from the influent of a mesophilic (30 degrees C) methanol fed upflow anaerobic sludge bed (UASB) reactor was investigated by coupling the reactor performance to the evolution of the Methanosarcina population of the bioreactor sludge. The reactor was operated at pH 7.0 and an organic loading rate (OLR) of 5-15 g COD l(-1) day(-1) for 191 days. A clear limitation of the specific methanogenic activity (SMA) on methanol due to the absence of nickel was observed after 129 days of bioreactor operation: the SMA of the sludge in medium with the complete trace metal solution except nickel amounted to 1.164 (+/-0.167) g CH(4)-COD g VSS(-1) day(-1) compared to 2.027 (+/-0.111) g CH(4)-COD g VSS(-1) day(-1) in a medium with the complete (including nickel) trace metal solution. The methanol removal efficiency during these 129 days was 99%, no volatile fatty acid (VFA) accumulation was observed and the size of the Methanosarcina population increased compared to the seed sludge. Continuation of the UASB reactor operation with the nickel limited sludge lead to incomplete methanol removal, and thus methanol accumulation in the reactor effluent from day 142 onwards. This methanol accumulation subsequently induced an increase of the acetogenic activity in the UASB reactor on day 160. On day 165, 77% of the methanol fed to the system was converted to acetate and the Methanosarcina population size had substantially decreased. Inclusion of 0.5 muM Ni (dosed as NiCl(2)) to the influent from day 165 onwards lead to the recovery of the methanol removal efficiency to 99% without VFA accumulation within 2 days of bioreactor operation.     

Isolation from poultry litter and characterization [corrected] of Staphylococcus spp. capable of growth in high phosphate conditions [corrected

AIMS: To isolate and characterize micro-organisms from poultry litter capable of growing under phosphate concentrations typical of poultry litter. METHODS AND RESULTS: Poultry litter extracts were plated onto brain-heart infusion medium (BHI) containing an additional 0.75 mol l(-1) phosphate (BHI-P). Colonies were screened for the presence of inclusion granules with five being selected for further study. All strains displayed identical biochemical characteristics consistent with Staphylococcus spp. and grouped with Staphylococcus spp. by comparative 16S rDNA analysis. Thus all five strains were identified as such. All strains displayed elevated intracellular phosphate levels when cultured in BHI-P broth (0.417-0.600 microg phosphate mg(-1) protein) vs BHI broth (0.075-0.093 microg phosphate mg(-1) protein). When grown using an austere semi-defined medium or BHI-P, Staph. sp. #7 displayed similar elevated intracellular phosphate levels compared with growth in BHI. CONCLUSIONS: Poultry litter contains novel Staphylococcus spp. capable of robust growth when exposed to phosphate levels comparable with that typically found in poultry litter. Data suggest intracellular phosphate levels in these strains increase in response to increasing phosphate in the medium or austere medium conditions. Intracellular phosphate did not reach levels comparable with known hyper-accumulating micro-organisms. SIGNIFICANCE AND IMPACT OF THE STUDY: These data suggest poultry litter possesses a resident microflora that thrives and accumulates intracellular phosphate in response to high phosphate conditions.     

Enzymatic pre-hydrolysis and anaerobic degradation of wastewaters with high fat contents

Dairy wastewaters containing elevated fat and grease levels (868 mg l^–1) were treated in an upflow anaerobic sludge blanket reactor (UASB) and resulted in effluents of high turbidity (757 nephelometric turbidity units), volatile suspended solids up to 944 mg l^–1 and COD removal below 50%. When the same dairy wastewater was pre-treated with 0.1% (w/v) of fermented babassu cake containing Penicillium restrictum lipases, turbidity and volatile suspended solids were decreased by 75% and 90%, respectively, and COD removal was as high as 90%.     

Treatment of poultry slaughterhouse wastewater in hybrid upflow anaerobic sludge blanket reactor packed with pleated poly vinyl chloride rings

In this study, the performance of 5.4 L hybrid upflow anaerobic sludge blanket (HUASB) reactor for treating poultry slaughterhouse wastewater under mesophilic conditions (29-35 °C), was investigated. After starting-up, the reactor was loaded up to an OLR of 19 kg COD/m³ d and achieved varied TCOD and SCOD removal efficiencies of 70-86% and 80-92%, respectively. The biogas was varied between 1.1 and 5.2 m³/m³ d with the maximum methane content of 72%. The maximum methane yield was 0.32 m³/kg COD_removed at an OLR of 9.27 kg COD/m³ d. Black matured granules of size between 2.5 and 5 mm were observed at the end of 225 d operation. RTD study showed the flow behavior was in mixed regime at the end of performance study. Step wise polynomial regression analysis was fitted well. Methanobacterium and Methanosaeta bacteria were dominant at the end of start-up whereas Methanosarcina, Cocci and rods were predominant at the end of performance studies.     

Use of the Static Granular Bed Reactor (SGBR) with anaerobic sludge to treat poultry slaughterhouse wastewater and kinetic modeling

Poultry slaughterhouses discharge very high amount of wastewaters and these wastewaters can be treated successfully at a very low cost using anaerobic treatment. In this study, the Static Granular Bed Reactor (SGBR), a newly developed anaerobic process which is fully anaerobic granule, and another Static Granular Bed Reactor containing both anaerobic granular biomass and non-granular biomass were employed for the treatment of poultry slaughterhouse wastewater. The objective of the use of two reactors having different types of anaerobic biomass is to evaluate whether anaerobic sludge could be used effectively instead of anaerobic granule, which is much more difficult to obtain than the other during the start up period. Average COD removal efficiencies were greater than 95% for both of the reactors. Furthermore, Grau second-order and modified Stover–Kincannon models were successfully used to develop a kinetic model of the experimental data with a high correlation coefficient (R² > 0.95).     

长白山阔叶红松林主要树种凋落叶分解速率及其与叶性状的关系

阔叶红松林是我国东北地区地带性顶级森林群落,对维持区域生态系统稳定性具有重要作用。对阔叶红松林内主要树种凋落叶分解过程及影响因素进行研究,有助于增加长白山阔叶红松林生态系统的基础数据,为明确阔叶红松林的养分循环和物质流动提供依据。选取了长白山阔叶红松林内30个常见乔灌树种和16个凋落叶性状,采用野外分解袋法和室内样品分析等方法研究了长白山阔叶红松林内主要树种凋落叶分解速率及其与凋落叶性状的关系。1年的野外分解实验表明,30个树种的凋落叶重量损失率表现出较大差异。不同树种凋落叶的重量损失率在20.56%—92.11%之间,以红松(Pinus koraiensis)质量损失率最低,东北山梅花(Philadelphus schrenkii)质量损失率最高。不同生活型树种的凋落叶在质量损失率上存在显著差异,以灌木树种凋落叶的质量损失率最高,小乔木次之,乔木树种质量损失率最低。Olson模型拟合结果表明,不同树种凋落叶的分解速率k以红松最低,瘤枝卫矛(Euonymus verrucosus)最高,分别为0.24和1.64。不同树种分解50%和95%所需的时间分别在0.43—2.86年,1.83—...     

人工调控措施下马尾松凋落叶化学质量变化及与分解速率的关系

马尾松凋落叶分解缓慢,促进其凋落物分解,提高养分归还速度,维持地力稳定,已成为马尾松人工林可持续经营中的关键问题。基于此,采用正交试验L_9(3~4)设计,选择菌剂、表面活性剂、不同碳氮营养液和有机肥料4种人工调控因素,在马尾松林下开展凋落叶分解调控试验,以掌握不同调控组合对凋落叶分解速率和化学质量的影响及作用效果等。结果表明:有机肥料和菌剂显著影响马尾松凋落叶分解速率,腐解剂2和鸡粪联合作用更利于分解。马尾松凋落叶在林下自然分解过程中,化学质量参数向着利于分解的方向变化,N、P以积累为主,C/N、C/P、L/N和L/P呈降低态势,人为调控措施加速了这一变化进程;不同调控措施对凋落叶化学质量参数的影响不尽相同,添加有机肥料有利于剩余凋落叶N、P含量升高,C/N、C/P、L/N和L/P的降低;菌剂腐解剂2有利于L/P、C/P的降低;表面活性剂OP-10有利于凋落叶L/N的降低。人工调控下,调控因素可通过改变凋落物化学质量影响其分解速率,N含量和C/N是影响马尾松凋落叶分解速率的主要因素;而P浓度、L/N、C/P、L/P对分解速率的影响不规律或不显著。     

Performance of a thermophilic sulfate and sulfite reducing high rate anaerobic reactor fed with methanol

Thermophilic sulfate and sulfite reduction was studied in lab-scale Expanded Granular Sludge Bed (EGSB) reactors operated at 65°C and pH 7.5 with methanol as the sole carbon and energy source for the sulfate- and sulfite-reducing bacteria. At a hydraulic retention time (HRT) of 10 h, maximum sulfite and sulfate elimination rates of 5.5 gSO₃ ^2- L^-1 day^-1 (100 % elimination) and 5.7 gSO₄ ^{2- -1} day^-1 (55% elimination) were achieved, resulting in an effluent sulfide concentration of approximately 1800 mgS L^-1. Sulfate elimination was limited by the sulfide concentration, as stripping of H₂S from the reactor with nitrogen gas was found to increase the sulfate elimination rate to 9.9 gSO₄ ^2- L^-1 day^-1 (100 % elimination). At a HRT of 3 h, maximum achievable sulfite and sulfate elimination rates were even 18 gSO₃ ^2- L^-1 day^-1 (100% elimination) and 11 gSO₄ ^2- L^-1 day^-1(50% elimination). At a HRT of 3 h, the elimination rate was limited by the biomass retention of the system. 5.5 ± 1.8% of the consumed methanol was converted to acetate, which was not further degraded by sulfate reducing bacteria present in the sludge. The acetotrophic activity of the sludge could not be stimulated by cultivating the sludge for 30 days under methanol-limiting conditions. Omitting cobalt as trace element from the influent resulted in a lower acetate production rate, but it also led to a lower sulfate reduction rate. Sulfate degradation in the reactor could be described by zeroth order kinetics down to a threshold concentration of 0.05 g L^-1, while methanol degradation followed Michaelis-Menten kinetics with a K_m of 0.037 gCOD L^-1.