Alkaline Dehydration of Human Urine Collected in Source-Separated Sanitation Systems Using Magnesium Oxide

Fresh human urine, after it is alkalized to prevent the enzymatic hydrolysis of urea, can be dehydrated to reduce its volume and to produce a solid fertilizer. In this study, we investigated the suitability of MgO to alkalize and dehydrate urine. We selected MgO due to its low solubility (<2 g·L−1) and relatively high saturation pH (9.9 ± 0.2) in urine. Using a laboratory-scale setup, we dehydrated urine added to pure MgO and MgO mixed with co-substrates (biochar, wheat bran, or calcium hydroxide) at a temperature of 50°C. We found that, dehydrating urine added to a mixture of MgO (25% w/w), biochar, and wheat bran resulted in a mass reduction of >90% and N recovery of 80%, and yielded products with high concentrations of macronutrients (7.8% N, 0.7% P and 3.9% K). By modeling the chemical speciation in urine, we also showed that ammonia stripping rather than urea hydrolysis limited the N recovery, since the urine used in our study was partially hydrolyzed. To maximize the recovery of N during alkaline urine dehydration using MgO, we recommend treating fresh/un-hydrolysed urine a temperature <40°C, tailoring the drying substrate to capture NH4+ as struvite, and using co-substrates to limit the molecular diffusion of ammonia. Treating fresh urine by alkaline dehydration requires only 3.6 kg MgO cap−1y−1 and a cost of US$ 1.1 cap−1y−1. Therefore, the use of sparingly soluble alkaline compounds like MgO in urine-diverting sanitation systems holds much promise.

Download Full-text

Fertilizer NPK from human urine and olive oil mill wastewaters

Journal of Water Reuse and Desalination ◽

10.2166/wrd.2011.036 ◽

2011 ◽

Vol 1 (3) ◽

pp. 152-159 ◽

Cited By ~ 3

Author(s):

Manuel Jimenez Aguilar

Keyword(s):

Olive Oil ◽

Human Urine ◽

Crop Production ◽

Silty Clay ◽

Nutrient Contents ◽

Ammonium N ◽

Npk Fertilizer ◽

The Impact ◽

Hydrolysis Of ◽

Fresh Urine

The objective of this work was to determine how some wastewater acids could be used to prevent the decomposition of urea into ammonia during storage. The effect of storing human urine with olive oil mill wastewaters (OOMW) or water bubbled with CO2 (BW), was studied. Moreover, the application of two levels of urine dissolved in water OOMW, has been studied in relation to the properties of two soils (loam and silty-clay loam). Our data provide evidence that human urine dissolved in OOMW significantly reduced the release of ammonium-N. Moreover, OOMW and CO2 significantly lowered the pH. A dosage higher 10% OOMW dissolved in fresh urine in volume could inhibit the hydrolysis of the urea for more than 6 months. Moreover, urine-N dissolved in OOMW significantly reduced the emission of nitrates from soils for 3 months, increasing K and P values. The application of urine with BW raised the soil pH and lowered the EC, but had no effect on nutrient contents. Thus, urine dissolved in OOMW and applied to soils could act as NPK-fertilizer. However, the impact of fertilization with human urine–OOMW–CO2 requires further investigation with respect to crop production and pollution.

Download Full-text

THE HYDROLYSIS OF THE CONJUGATED OESTROGENS IN HUMAN URINE

Acta Endocrinologica ◽

10.1530/acta.0.0070240 ◽

1951 ◽

Vol 7 (1) ◽

pp. 240-256 ◽

Cited By ~ 16

Author(s):

G. F. MARRIAN ◽

W. S. BAULD

Keyword(s):

Human Urine ◽

Hydrolysis Of

Download Full-text

The Sustainable Production of a Novel Laccase from Wheat Bran by Bordetella sp. JWO16: Toward a Total Environment

Catalysts ◽

10.3390/catal11060677 ◽

2021 ◽

Vol 11 (6) ◽

pp. 677

Author(s):

John Onolame Unuofin

Keyword(s):

Wheat Bran ◽

Contaminated Soils ◽

Residual Activity ◽

Dye Decolorization ◽

Fermentation Medium ◽

Biochemical Properties ◽

Synthetic Dyes ◽

High Concentrations ◽

Capital Intensive ◽

Agroindustrial Residue

Laccase is increasingly adopted in diverse industrial and environmental applications, due to its readily accessible requirements for efficient catalytic synthesis and biotransformation of chemicals. However, it is perceived that its industrial production might incur some unfavorable overhead, which leads to expensive market products, and the corresponding negative environmental feedback, due to the use of capital-intensive and precarious chemicals. To this end, this study was designed to evaluate the performance indicators of the valorization of wheat bran by a novel Jb1b laccase and its subsequent application in waste minimization and water management, on a laboratory scale. Optimal Jb1b laccase was produced in submerged fermentation medium containing wheat bran, an agroindustrial residue, through response surface methodology (RSM) algorithm, and was applied in dye decolorization and denim bioscouring, respectively. Results showed that the resultant enzyme manifested unique biochemical properties, such as enhanced tolerance at certain physicochemical conditions, with a residual activity of at least ca. 76%. Furthermore, phenomenally high concentrations of synthetic dyes (0.2% w v−1) were decolorized over 56 h, and a 6 h mediator-supported simultaneous denim bleaching and decolorization of wash effluent was observed. The sustainability of the production and application processes were inferred from the reusability of the fermentation sludge as a potential biofertilizer, with subsequent prospects for the biostimulation and bioaugmentation of contaminated soils, whereas the decolorized water could be adopted for other uses, amongst which horticulture and forestry are typical examples. These phenomena therefore authenticate the favorable environmental feedbacks and overhead realized in this present study.

Download Full-text

Engineering of Streptoalloteichus tenebrarius 2444 for Sustainable Production of Tobramycin

Molecules ◽

10.3390/molecules26144343 ◽

2021 ◽

Vol 26 (14) ◽

pp. 4343

Author(s):

Lena Mitousis ◽

Hannes Maier ◽

Luka Martinovic ◽

Andreas Kulik ◽

Sigrid Stockert ◽

...

Keyword(s):

Aminoglycoside Antibiotic ◽

Biosynthetic Gene Cluster ◽

Genetically Engineered ◽

Sustainable Production ◽

Biosynthetic Gene ◽

Strain Development ◽

Antibiotic Agent ◽

Phenotypic Stability ◽

High Concentrations ◽

Hydrolysis Of

Tobramycin is a broad-spectrum aminoglycoside antibiotic agent. The compound is obtained from the base-catalyzed hydrolysis of carbamoyltobramycin (CTB), which is naturally produced by the actinomycete Streptoalloteichus tenebrarius. However, the strain uses the same precursors to synthesize several structurally related aminoglycosides. Consequently, the production yields of tobramycin are low, and the compound’s purification is very challenging, costly, and time-consuming. In this study, the production of the main undesired product, apramycin, in the industrial isolate Streptoalloteichus tenebrarius 2444 was decreased by applying the fermentation media M10 and M11, which contained high concentrations of starch and dextrin. Furthermore, the strain was genetically engineered by the inactivation of the aprK gene (∆aprK), resulting in the abolishment of apramycin biosynthesis. In the next step of strain development, an additional copy of the tobramycin biosynthetic gene cluster (BGC) was introduced into the ∆aprK mutant. Fermentation by the engineered strain (∆aprK_1-17L) in M11 medium resulted in a 3- to 4-fold higher production than fermentation by the precursor strain (∆aprK). The phenotypic stability of the mutant without selection pressure was validated. The use of the engineered S. tenebrarius 2444 facilitates a step-saving, efficient, and, thus, more sustainable production of the valuable compound tobramycin on an industrial scale.

Download Full-text

Integrated faecal sludge treatment and recycling through constructed wetlands and sunflower plant irrigation

Water Science & Technology ◽

10.2166/wst.2006.846 ◽

2006 ◽

Vol 54 (11-12) ◽

pp. 155-164 ◽

Cited By ~ 4

Author(s):

T. Koottatep ◽

C. Polprasert ◽

S. Hadsoi

Keyword(s):

Plant Biomass ◽

Tap Water ◽

Oxygen Demand ◽

Application Rate ◽

Solid Loading ◽

Sunflower Plant ◽

Increase With Increase ◽

High Concentrations ◽

Sanitation Systems ◽

Faecal Sludge

Faecal sludge (FS) from the on-site sanitation systems is a nutrient-rich source but can contain high concentrations of toxic metals and chemicals and infectious micro-organisms. The study employed 3 vertical-flow CW units, each with a dimension of 5×5×0.65 m (width×length×media depth) and planted with cattails (Typha augustifolia). At the solid loading rate of 250 kg total solids (TS)/m2.yr and a 6-day percolate impoundment, the CW system could achieve chemical oxygen demand (COD), TS and total Kjeldahl nitrogen (TKN) removal efficiencies in the range of 80–96%. A solid layer of about 80 cm was found accumulated on the CW bed surface after operating the CW units for 7 years, but no clogging problem has been observed. The CW percolate was applied to 16 irrigation sunflower plant (Helianthus annuus) plots, each with a dimension of 4.5×4.5 m (width×length). In the study, tap water was mixed with 20%, 80% and 100% of the CW percolate at the application rate of 7.5 mm/day. Based on a 1-year data in which 3 crops of plantation were experimented, the contents of Zn, Mn and Cu in soil of the experimental plots were found to increase with increase in CW percolate ratios. In a plot with 100% of CW percolate irrigation, the maximum Zn, Mn and Cu concentrations of 5.0, 12.3 and 2.5 mg/kg, respectively, were detected in the percolate-fed soil, whereas no accumulation of heavy metals in the plant tissues (i.e. leaves, stems and flowers) of the sunflower were detected. The highest plant biomass yield and oil content of 1000 kg/ha and 35%, respectively, were obtained from the plots fed with 20% or 50% of the CW percolate.

Download Full-text

Pectin methylesterase, metal ions and plant cell-wall extension. Hydrolysis of pectin by plant cell-wall pectin methylesterase

Biochemical Journal ◽

10.1042/bj2790343 ◽

1991 ◽

Vol 279 (2) ◽

pp. 343-350 ◽

Cited By ~ 81

Author(s):

J Nari ◽

G Noat ◽

J Ricard

Keyword(s):

Cell Wall ◽

Metal Ions ◽

Plant Cell ◽

Plant Cell Wall ◽

Direct Interaction ◽

Enzyme Reaction ◽

Pectin Methylesterase ◽

High Concentrations ◽

Enzyme Molecules ◽

Hydrolysis Of

The hydrolysis of p-nitrophenyl acetate catalysed by pectin methylesterase is competitively inhibited by pectin and does not require metal ions to occur. The results suggest that the activastion by metal ions may be explained by assuming that they interact with the substrate rather than with the enzyme. With pectin used as substrate, metal ions are required in order to allow the hydrolysis to occur in the presence of pectin methylesterase. This is explained by the existence of ‘blocks’ of carboxy groups on pectin that may trap enzyme molecules and thus prevent the enzyme reaction occurring. Metal ions may interact with these negatively charged groups, thus allowing the enzyme to interact with the ester bonds to be cleaved. At high concentrations, however, metal ions inhibit the enzyme reaction. This is again understandable on the basis of the view that some carboxy groups must be adjacent to the ester bond to be cleaved in order to allow the reaction to proceed. Indeed, if these groups are blocked by metal ions, the enzyme reaction cannot occur, and this is the reason for the apparent inhibition of the reaction by high concentrations of metal ions. Methylene Blue, which may be bound to pectin, may replace metal ions in the ‘activation’ and ‘inhibition’ of the enzyme reaction. A kinetic model based on these results has been proposed and fits the kinetic data very well. All the available results favour the view that metal ions do not affect the reaction through a direct interaction with enzyme, but rather with pectin.

Download Full-text

Research on the hydrolysis of human urine using biological activated carbon and its application in bioregenerative life support system

Acta Astronautica ◽

10.1016/j.actaastro.2018.11.031 ◽

2019 ◽

Vol 155 ◽

pp. 191-199

Author(s):

Guorong Zhu ◽

Guanghui Liu ◽

Dianlei Liu ◽

Haoxiang Chen ◽

Chenhao Fang ◽

...

Keyword(s):

Activated Carbon ◽

Support System ◽

Human Urine ◽

Life Support ◽

Life Support System ◽

Biological Activated Carbon ◽

Bioregenerative Life Support System ◽

Hydrolysis Of ◽

Bioregenerative Life Support

Download Full-text

Fungal cellulases: production by solid-state cultivation in packed-bed bioreactor using solid agro-industrial by-products as substrates and application for hydrolysis of sugarcane bagasse

Semina Ciências Agrárias ◽

10.5433/1679-0359.2020v41n5supl1p2097 ◽

2020 ◽

pp. 2097-2116 ◽

Cited By ~ 1

Author(s):

Priscila Aparecida Casciatori Frassatto ◽

Fernanda Perpétua Casciatori ◽

João Cláudio Thoméo ◽

Eleni Gomes ◽

Maurício Boscolo ◽

...

Keyword(s):

Solid State ◽

Sugarcane Bagasse ◽

Enzyme Production ◽

Packed Bed ◽

Aeration Rate ◽

Hydrolysis Time ◽

Enzymatic Extract ◽

Packed Bed Bioreactor ◽

High Concentrations ◽

Hydrolysis Of

Cellulases are essential for the hydrolysis of lignocellulosic materials in the production of second generation ethanol. Solid-state cultivation is a process that provides high concentrations of enzymes that can be used in this hydrolysis. The objectives of this work were to produce cellulases by cultivating the fungus Myceliophthora thermophila I-1D3b in a packed bed bioreactor with sugarcane bagasse (SCB) and wheat bran (WB) as substrate and to evaluate the efficiency of the enzymatic extract in the hydrolysis of SCB in natura (BIN) and pretreated with ozone, alkali and ultrasound (BOU). The conditions for enzyme production in the bioreactor were SCB:WB at a ratio of 2.3:1 (w/w), 75 % moisture content; 45 ºC; aeration rate 240 L h-1 and 96 h. The enzyme production was evaluated by endoglucanase, xylanase, filter paper (FPU) and ?-glycosidase activities. For the application of the enzymes, a central composed response surface design with 5 repetitions of the central point was used, taking enzyme volume and hydrolysis time as factors. Such cultivation yielded the following enzymatic activities: 723 U gss-1 of endoglucanases, 2024 U gss-1 of xylanase, 12.6 U gss-1 of FPU and 41 U gss-1 of ?-glucosidase. The results of the application tests indicated the best conditions as 7.0 ml of the enzyme extract (4.2 FPU) and 6 hours for BIN and BOU. The best cellulose-glucose conversions were obtained for BOU, reaching 32.1 % at 65 ºC. In conclusion, the enzyme production in the packed bed bioreactor was efficient and BOU pretreatment improved the hydrolysis of biomass, increasing the efficiency of conversion of cellulose to glucose.

Download Full-text

Hydrogen generation by both acidic and catalytic hydrolysis of sodium borohydride

Catalysis for Sustainable Energy ◽

10.1515/cse-2018-0006 ◽

2018 ◽

Vol 5 (1) ◽

pp. 41-48 ◽

Cited By ~ 4

Author(s):

Olga V. Netskina ◽

Tihon N. Filippov ◽

Oksana V. Komova ◽

Valentina I. Simagina

Keyword(s):

Hydrogen Evolution ◽

Sodium Borohydride ◽

Hydrogen Generation ◽

Hydrogen Release ◽

Catalytic Hydrolysis ◽

Hydrogen Storage Materials ◽

Acidic Solutions ◽

High Concentrations ◽

Sulfuric And Hydrochloric Acids ◽

Hydrolysis Of

Abstract Sodium borohydride tablets have been employed as hydrogen-storage materials. Hydrogen release was performed by acidic hydrolysis where solutions of sulfuric and hydrochloric acids were added to the tablets, and by catalytic hydrolysis where water was added tablets of solid-state NaBH4/Co composite. In acidic solutions hydrogen evolution occurred instantaneously, and at high concentrations of acids the releasing hydrogen contained an admixture of diborane. Hydrogen evolution from the solidstate NaBH4/Co composite proceeded at a uniform rate of 13.8±0.1 cm3·min-1, water vapor being the only impurity in the evolving gas.

Download Full-text