Integrated biological and electro-chemical treatment of swine manure

2004 ◽  
Vol 49 (5-6) ◽  
pp. 427-434 ◽  
Author(s):  
K.J. Chae ◽  
S.K. Yim ◽  
K.H. Choi ◽  
S.K. Kim ◽  
W.K. Park

A full-scale biogas plant was applied to the processing of 10m3/d of swine manure. The plant consisted of an anaerobic digester and an engine-generator. The digester operation resulted in an 81% of COD removal, a 55% of VS reduction, and methane-rich biogas production that is used to generate electrical and thermal energies. To further treat the digested manure, for compliance with discharge limits, an electro-chemical oxidation with a dimensionally sable anode was investigated for the simultaneous elimination of both the remaining COD and ammonia nitrogen. It was able to reduce NH4+-N levels from as high as 1552 down to 25 mg/L in 160 min, and the COD from 1542 to 0.21 mg/L under the experimental conditions of 8 V, 30 A and 20000 μS/cm. The amount of electricity required for a 90% removal of the residual COD and ammonia in 1 m3 of filtered digester manure, via electrochemical oxidation, were approximately 153 and 151 kWh, respectively. These values exceed the maximum potential capacity of the biogas-originated electricity through the digestion of swine manure containing normal VS content. However, approximately 50% of the required electricity for the electrochemical oxidation could be supplied from the engine-generator.

2021 ◽  
pp. 100716
Author(s):  
Deisi Cristina Tápparo ◽  
Daniela Cândido ◽  
Ricardo Luis Radis Steinmetz ◽  
Christian Etzkorn ◽  
André Cestonaro do Amaral ◽  
...  

1989 ◽  
Vol 42 (9) ◽  
pp. 1527 ◽  
Author(s):  
TH Randle ◽  
AT Kuhn

Lead dioxide is a strong oxidizer in sulfuric acid, consequently electrochemical oxidation of solution species at a lead dioxide anode may occur by a two-step, C-E process (chemical oxidation of solution species by PbO2 followed by electrochemical regeneration of the reduced lead dioxide surface). The maximum rate of each step has been determined in sulfuric acid for specified lead dioxide surfaces and compared with the rates observed for the electrochemical oxidation of cerium(III) and manganese(II) on the same electrode surfaces. While the rate of electrochemical oxidation of a partially reduced PbO2 surface may be sufficient to support the observed rates of CeIII and MnII oxidation at the lead dioxide anode, the rate of chemical reaction between PbO2 and the reducing species is not. Hence it is concluded that the lead dioxide electrode functions as a simple, 'inert' electron-transfer agent during the electrochemical oxidation of CellI and MnII in sulfuric acid. In general, it will most probably be the rate of the chemical step which determines the feasibility or otherwise of the C-E mechanism.


1998 ◽  
Vol 1998 ◽  
pp. 173-173
Author(s):  
C.M. Korndörfer ◽  
A. L. Abdalla ◽  
E. Crossara

In the Brazilian savanna region, which covers 2.1 million km2, roughage production is irregular during the year. However the manufacture of passion fruit juice produces approximately 13,000,000 ton per year of industrial residue which consist of fruit pulp and seeds (FPSR) (Medina, 1980). Beef and dairy cattle farmers are feeding it to their livestock with no knowledge of its nutritive value or concern for its pollution aspects. The FPSR is left in piles outside on the ranches and fluid effluent is often observed reaching streams and contaminating the environment. Furthermore it is a good medium for fly proliferation which stresses the animals and reduces profits. The objective of this study was to demonstrate to the farmers a better way for storing the FPSR and to determine its nutritional value for ruminants.The FPSR was stored in triplicate experimental mino-silos (200 1) in a complete 2x2 factorial design to observe the effects of 48-h wilting (sun dry) and anaerobic conditions. Open mini-silos were left uncovered while in anaerobic mini-silos the FPSR was sealed in plastic bags and covered with sacks of soil. Treatments were: Tl wilted and anaerobic; T2 wilted and open; T3 unwilted and anaerobic; T4 unwilted and open. The mini-silos were sampled at 30-day intervals for up to ll2 days. The samples were analysed for dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), lignin (LIN), phenolic compounds (PHEN), ammonia nitrogen (NH3 -N), soluble carbohydrats (CHO sol) and pH. The DM effective degradability (DMED) was determined “in situ” using six Santa Inês male sheep fitted with rumen cannula and fed with a mixture 80:20 diet containing grass pasture and concentrate (160 g CP/kg DM). The effects of experimental conditions were analysed in a factorial treatment structure and tested by analysis of variance. Treatment means were compared by contrasts.


2001 ◽  
Vol 44 (1) ◽  
pp. 33-39 ◽  
Author(s):  
O. Tornes

Norway is a leading country on wastewater treatment comprising chemical precipitation processes. This is because Norwegian effluent standards to the North Sea have traditionally focused on phosphorus removal. In most cases, chemical treatment therefore has been considered to give lower investment and operating costs than biological treatment. Norwegian wastewater policy and management is based on the EU guidelines resulting from the EEA (European Economic Area) Agreement. According to the 1991 Urban Wastewater Treatment Directive, this will in most cases require secondary treatment. However, primary treatment can be accepted for plants larger than 10,000 PT with effluents to less sensitive coastal areas, if no negative environmental impacts can be proved. The main objective of the Regional Water, Sewerage and Waste Company (IVAR) is to comply with the prevailing effluent limits at lowest possible cost. During the past four years, IVAR has therefore undertaken comprehensive optimising of the precipitation process including full-scale experiments with different coagulant dosing control systems and different types of coagulants. IVAR also accomplished a feasibility study of introducing biological treatment as an alternative to chemical treatment. Under the prevailing frame conditions of discharge requirements and sludge deposit costs, it is not economically feasible to change to organic coagulants or biological treatment. This conclusion might have to be altered later resulting from the implementation of new EU regulations and increasing sludge deposit costs. This paper presents results from full-scale experiments, extracts from the feasibility study and a comparison of costs. Furthermore, the practical consequences of implementing the EU-guidelines are discussed.


Catalysts ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 540
Author(s):  
Zainab Mussa ◽  
Fouad Al-Qaim ◽  
Ali Yuzir ◽  
Hirofumi Hara ◽  
Shamila Azman ◽  
...  

This paper describes an electrochemical treatment process of hydrochlorothiazide (HDZ) under different conditions such as initial concentration, sodium chloride and applied voltage. In this present study, HDZ was treated by electrochemical oxidation process using graphite-PVC composite electrode as anode and Platinum (Pt) as cathode. All results were analyzed using liquid chromatography-time of flight/mass spectrometry (LC-TOF/MS). It was found that at high applied voltages, and high amounts of NaCl, the electrochemical treatment process was more efficient. The removal% of HDZ was 92% at 5 V after 60 min. From the obtained results, the electrochemical oxidation process of HDZ followed pseudo first order with rate constant values ranged between 0.0009 and 0.0502 min−1, depending on the experimental conditions. Energy consumption was also considered in this study, it was ranged between 0.9058 and 5.56 Wh/mg using 0.5, 0.3 and 0.1 g NaCl within interval times of (10, 20, 30, 40, 50, 60, 70, and 80 min). Five chlorinated and one non-chlorinated by-products were formed and analyzed in negative ionization (NI) mode during the electrochemical process. Due to the strong oxidizing potential of the chlorine (Cl2) and hypochlorite ion (ClO−), HDZ and its by-products were removed after 140 min. Furthermore, a novel synthesis of chlorothiaizde as one of the new by-products was reported in this present study. Toxicity was impacted by the formation of the by-products, especially at 20 min. The inhibition percentage (I%) of E. coli bacteria was decreased to be the lowest value after 140 min.


1997 ◽  
Vol 36 (1) ◽  
pp. 255-262 ◽  
Author(s):  
Denny S. Parker ◽  
Tom Jacobs ◽  
Erich Bower ◽  
Dennis W. Stowe ◽  
Greg Farmer

Tertiary nitrifying trickling filters (NTFs) at the Littleton/Englewood wastewater treatment plant provide for nitrification to meet seasonally varying effluent requirements for ammonia nitrogen. Operation of the full-scale facilities during the past two years demonstrates highly efficient oxidation of ammonia and the effectiveness of biofilm control strategies. A decline in nitrification performance caused by predators was successfully corrected by the use of a special alkaline backwash feature which controlled the level of larval development within the NTFs.


2001 ◽  
Vol 44 (1) ◽  
pp. 161-166 ◽  
Author(s):  
Q. Wu ◽  
P. L. Bishop ◽  
T. C. Keener ◽  
J. Stallard ◽  
L. Stile

Anaerobic sludge digestion is a widely adopted process for sludge stabilization. Phosphate removal from anaerobic supernatant is necessary to limit the phosphate returned to the head of the treatment plant, thereby improving the overall treatment efficiency. In this study, magnesium hydroxide (Mg(OH)2) was used to improve the sludge digestion efficiency and to remove phosphorus from anaerobic supernatant. The anaerobic sludge digestion experiment was conducted at a pilot scale, and the results showed that applying Mg(OH)2 to anaerobic sludge digester resulted in a larger reduction in SS and COD, a higher biogas production rate, a lower level of phosphate and ammonia nitrogen concentrations in the sludge supernatant and an improved sludge dewaterability. Research results at both lab scale and pilot scale on phosphorus removal from anaerobic supernatant using Mg(OH)2 showed that a high removal of phosphorus can be achieved through the addition of Mg(OH)2. The required reaction time depends on the initial phosphorus concentration and the Mg(OH)2 dosage.


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