scholarly journals Biogas Upgrading and Ammonia Recovery from Livestock Manure Digestates in a Combined Electromethanogenic Biocathode—Hydrophobic Membrane System

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 503
Author(s):  
Miriam Cerrillo ◽  
Laura Burgos ◽  
August Bonmatí

Anaerobic digestion process can be improved in combination with bioelectrochemical systems in order to recover energy and resources from digestates. An electromethanogenic microbial electrolysis cell (MEC) coupled to an ammonia recovery system based on hydrophobic membranes (ARS-HM) has been developed in order to recover ammonia, reduce organic matter content and upgrade biogas from digested pig slurry. A lab-scale dual-chamber MEC was equipped with a cation exchange membrane (CEM) and ARS with a hydrophobic membrane in the catholyte recirculation loop, to promote ammonia migration and absorption in an acidic solution. On the other hand, an electromethanogenic biofilm was developed in the biocathode to promote the transformation of CO2 into methane. The average nitrogen transference through the CEM was of 0.36 gN m−2 h−1 with a removal efficiency of 31%, with the ARS-HM in the catholyte recirculation loop. The removal of ammonia from the cathode compartment helped to maintain a lower pH value for the electromethanogenic biomass (7.69 with the ARS-HM, against 8.88 without ARS-HM) and boosted methane production from 50 L m−3 d−1 to 73 L m−3 d−1. Results have shown that the integration of an electromethanogenic MEC with an ARS-HM allows for the concomitant recovery of energy and ammonia from high strength wastewater digestates.

Processes ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1916
Author(s):  
Míriam Cerrillo ◽  
Laura Burgos ◽  
Joan Noguerol ◽  
Victor Riau ◽  
August Bonmatí

Ammonia and phosphate, which are present in large quantities in waste streams such as livestock manure, are key compounds in fertilization activities. Their recovery will help close natural cycles and take a step forward in the framework of a circular economy. In this work, a lab-scale three-chambered microbial electrolysis cell (MEC) has been operated in continuous mode for the recovery of ammonia and phosphate from digested pig slurry in order to obtain a nutrient concentrated solution as a potential source of fertilizer (struvite). The maximum average removal efficiencies for ammonium and phosphate were 20% ± 4% and 36% ± 10%, respectively. The pH of the recovered solution was below 7, avoiding salt precipitation in the reactor. According to Visual MINTEQ software modelling, an increase of pH value to 8 outside the reactor would be enough to recover most of the potential struvite (0.21 mmol L−1 d−1), while the addition of up to 0.2 mM of magnesium to the nutrient recovered solution would enhance struvite production from 5.6 to 17.7 mM. The application of three-chambered MECs to the recovery of nutrients from high strength wastewater is a promising technology to avoid ammonia production through industrial processes or phosphate mineral extraction and close nutrient natural cycles.


2012 ◽  
Vol 518-523 ◽  
pp. 319-325
Author(s):  
Dian Qing Lu ◽  
Hong Wang ◽  
Xu Lei Hou ◽  
Xiao Mei Liu

Distribution of organic matter and effect of wetland types and pH on organic matter were studied in sediment of lakeside belt in east Dongting Lake according to taking 56 samples from surface to 20cm and 52 samples from 20cm to 40cm. The results showed that the average content of organic matter was 15.40g/kg from surface to 20cm and 12.02g/kg from 20cm to 40cm in sediment of lakeside belt in east Dongting Lake. Spatial distribution of organic matter could be expressed as middle variation. Wetland types were classed into silt beach, lake marsh beach and reed beach in Dongting Lake region and influenced distribution of organic matter because of difference variance on hydraulic dynamics condition and retarding effect of vegetation on water flow velocity. Order of organic matter content in sediment was the lake marsh beach > reed beach > silt beach in 0-20cm and 20-40cm layers in lakeside belt in east Dongting Lake. Organic matter contents decreased in turn from 0-20cm to 20-40cm in lake marsh and reed beaches and increased in silt beaches. Values of pH in sediment were slightly alkaline in whole studied region. Negative correlation was established between organic matter content and pH value. The results will provide base data and science reference for controlling and recovery of sediment pollution in east Dongting Lake.


2019 ◽  
Vol 80 (4) ◽  
pp. 717-726 ◽  
Author(s):  
Jingna Yan ◽  
Xiaohan Zhang ◽  
Wenting Lin ◽  
Chen Yang ◽  
Yuan Ren

Abstract Diclofenac (DCF) is one of the most frequently detected non-steroidal anti-inflammatory drugs (NSAIDs) in the water environment. One of the main removal routes of DCF in wastewater is sludge adsorption, and the mechanisms need to be investigated. In this study, the effects of adsorption time, temperature, pH value, and ionic strength on the adsorption of DCF on suspended particles (SP), secondary sedimentation tank sludge (SSTS) and concentrated sludge (CS) were investigated. The results showed that most of the adsorption of DCF by the three matrices was conducted in the first 4 h and equilibrium was achieved at 8 h. The adsorption kinetics were well fitted with the pseudo-second-order model and the rate constants were 0.29–0.88 mg·(μg·min)−1, with chemical adsorption as the dominant one. Adsorption isotherm conformed to Freundlich, Langmuir and Linear adsorption isotherm models. The order of adsorption capacity was: CS > SSTS > SP, which was proportional to the organic matter content and specific surface area of the adsorbents. The decrease of the pH value and the increase of ionic strength promoted the adsorption of DCF. The results can provide data support for the removal of DCF from different treatment unit types in wastewater treatment plants.


2019 ◽  
Vol 178 ◽  
pp. 108669 ◽  
Author(s):  
Manuel Conde-Cid ◽  
Gustavo Ferreira-Coelho ◽  
Avelino Núñez-Delgado ◽  
David Fernández-Calviño ◽  
Manuel Arias-Estévez ◽  
...  

1989 ◽  
Vol 69 (1) ◽  
pp. 39-47 ◽  
Author(s):  
A. NDAYEGAMIYE ◽  
D. CÔTÉ

Chemical and biological properties were evaluated in 1987 on an acidic silty loam soil following a long-term field study established in 1978 and cultivated with silage corn. Treatments included a control, solid cattle manure (20, 40 and 60 Mg ha−1 FYM) and pig slurry (60, 120 m3 ha−1 SLU) applied every 2 yr and annually, respectively. No fertilizer was applied. The results of this study have shown that neither treatment significantly affected soil pH values, total-N contents and C:N ratios compared to the control. The cation exchange capacity (CEC) of the soil was significantly higher with FYM treatment than with control or SLU application. The highest rates of FYM and SLU have also increased (P < 0.05) soil organic carbon, microbial activity and potentially mineralizable nitrogen. The soil microflora populations (bacteria, fungi, actinomycetes, ammonifiers and nitrifiers) were greatly improved by both treatments. There were no significant differences in organic matter content or the relative amount of humic and fulvic acids between FYM and SLU plots. In spite of these results, FYM application (40 and 60 Mg ha−1) did affect more significantly the distribution of organic carbon in HA and the E4/E6 quotients than SLU additions. Humic acids extracted from SLU amended soils had a lower C content and lower E4/E6 ratios than humic acids from FYM soils. Long-term SLU application did not contribute to decreased organic matter content, CEC and humic acids yield, probably because of optimal organic residues returned to the soil by the corn crops. The FYM application generally improved soil chemical and biological properties. For a sustainable soil productivity, long-term SLU application should then be avoided in rotation in which small amounts of plant residues are returned, especially on soils with low organic matter contents. Key words: Organic matter, microbial activity, nitrogen mineralization potential, CEC, solid cattle manure, pig slurry


Agronomy ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 493
Author(s):  
Beatriz Moreno-García ◽  
Mónica Guillén ◽  
Dolores Quílez

The great increase in livestock production in some European areas makes it necessary to recycle organic slurries and manures and to integrate them in crop production. In Northeast Spain, the application of pig slurry (PS) is being extended to alternative crops such as rice due to the great increase in pig production. However, there is a lack of information of the effect of substitution of synthetic fertilizers with pig slurry on greenhouse gas (GHG) emissions in rice crop, and this information is key for the sustainability of these agricultural systems. The aim of this study was to evaluate the effect of the substitution of mineral fertilizers by PS on GHG emissions in Mediterranean flooded rice cultivation conditions under optimal nitrogen (N) fertilization. Two field experiments were carried out in two different (contrasting) soil types with different land management. Site 1 had been cultivated for rice in the previous three years with no puddling practices. Site 2 had been cultivated for rice for more than 15 years with puddling tillage practices and had higher organic matter content than site 1. The cumulative nitrous oxide emissions during the crop season were negative at both sites, corroborating that under flooded conditions, methane is the main contributor to global warming potential rather than nitrous oxide. The substitution of mineral fertilizer with PS before seeding at the same N rate did not increase emissions in both sites. However, at site 1 (soil with lower organic matter content), the higher PS rate applied before seeding (170 kg N ha−1) increased methane emissions compared to the treatments with lower PS rate and mineral fertilizer before seeding (120 kg N ha−1) and complemented with topdressing mineral N. Thus, a sustainable strategy for inclusion of PS in rice fertilization is the application of moderate PS rates before seeding (≈120 kg N ha−1) complemented with mineral N topdressing.


1969 ◽  
Vol 36 (2) ◽  
pp. 155-160
Author(s):  
M. A. Lugo López ◽  
F. Abruña ◽  
J. Roldán

The quantity of limestone required to bring the pH of various acid Puerto Rican soils to 6.5 was investigated and found to vary from several hundred to several thousands pounds per acre. To investigate the relation of clay-mineral type, clay content, cation-exchange capacity, organic-matter content, and pH to lime requirement, these properties were determined for several soils. A highly significant regression of lime requirement on pH was obtained which can be expressed by the equation: Y = 18.39 — 3.196 X, where Y is the lime requirement and X is the pH value. Multiple regressions including other factors did not significantly increase the variability which could be explained on terms of the first regression. Further analysis were made by arranging the data according to the predominant clay mineral. For kaolinitic soils highly significant correlations were obtained between lime requirement and either pH or cation exchange capacity. The regressions were: (a) Y = 15.26 — 2.632 pH, and (b) Y = 3.048 + 0.5774 (cation-exchange capacity), where Y is the lime requirement. A regression of lime requirement on both factors did not significantly increase the variability explained by the second equation. No significant regressions were obtained for beidellitic soils.


2020 ◽  
Vol 204 ◽  
pp. 01013
Author(s):  
Gang Li ◽  
Ruiqing Zhang ◽  
Ying Wang ◽  
Nan Lu ◽  
Yang Wei ◽  
...  

In order to understand the soil pH and main nutrient characteristics of newly added cultivated land in the eastern part of Guanzhong, and 160 soil samples were collected in 2016, the soil pH, organic matter, total nitrogen, available phosphorus and available potassium in Heyang County were studied The suitability distribution of the indicators, using stepwise regression and path analysis methods, analyzes the direct relationship between soil pH and soil nutrients, and provides a theoretical basis for improving the newly added cultivated land. The results showed that the soil pH in Heyang County varied from 8.42 to 9.67, the soil organic matter content varied from 3.46 to 17.93 g/kg, the soil total nitrogen content varied from 0.13 to 5.61 g/kg, and the soil available phosphorus changed The range is 1.73 ~ 63.06 mg/kg, and the soil available potassium range is 46.50 ~ 523.74. The newly added soil has a certain nutrient basis, but it should be further adjusted and improved during the cultivation process. The direct positive effect on soil pH value is mainly soil organic matter, and the direct negative effect is mainly soil available phosphorus. By adjusting the organic matter, total nitrogen, available phosphorus and available potassium in the soil, the pH value of the soil can be effectively improved, so that the newly cultivated soil is suitable for the growth of local crops.


Sign in / Sign up

Export Citation Format

Share Document