scholarly journals Simple improvement of digested sludge quality: is postaeration the key?

2019 ◽  
Vol 80 (9) ◽  
pp. 1633-1642
Author(s):  
M. Vojtiskova ◽  
B. Satkova ◽  
J. Bindzar ◽  
P. Jenicek

Abstract Postaeration, where digested sludge is introduced into aerobic conditions, is a technology that could improve the quality of sludge and sludge liquor in many ways. Although it is a fairly simple process, only few data about the effect of postaeration have been published. In this study, batch experiments have been performed first, indicating that postaeration affects the total ammonia nitrogen (TAN) and sludge dewaterability. In the removal of TAN, both stripping and biological oxidation can play an important role depending on specific condition. Then the postaeration was investigated in a semicontinuous batch reactor. In addition, the effect of postaeration on the concentration of selected micropollutants such as pharmaceuticals, EOX and AOX was studied. The hydraulic retention time (HRT) of 8, 6, 4 and 2 days and different aeration intensities were tested. The TAN removal efficiency achieved was about 40–60%, sludge dewaterability expressed by sludge cake total solids (TS) concentration after dewatering improved relatively by 5–30%. In addition, TS degradation is also taking place and therefore the reduction of the amount of final sludge to be disposed could be even higher. The biggest changes in observed parameters were recorded at the longest HRT.

2016 ◽  
Vol 1 (1) ◽  
pp. 39
Author(s):  
Fatmawati Fatmawati ◽  
K Soewardi ◽  
T Kusumastanto ◽  
L Adrianto

The purpose of this study was to estimate the carrying capacity of coastal waters of the pond effluent. The data required for analysis of mass balance models of carrying capacity is based on the total ammonia-nitrogen (NH3-N) concentration in coastal waters. Estimation of carrying capacity with the concept mass balance model using the formula Tchobanoglous (1990) and Predalumpaburt (1996) in Tookwinas (1998) which has been modified by including the formula Widigdo and Pariwono (2001). Carrying capacity of coastal waters of Sebamban Baru Village, Tanah Bumbu Regency maximum pond area calculation may be developed for aquaculture area of 412,583 hectares, this shows that the concentration of ammonia released by the pond has not been an impact on the quality of coastal waters because the existing pond area is new opened an area of 368.542 ha has not exceeded the carrying capacity of the mass balance.


2021 ◽  
Vol 34 ◽  
pp. 5
Author(s):  
Lestari L. Widowati ◽  
S. Budi Prayitno ◽  
Sri Rejeki ◽  
Tita Elfitasari ◽  
Pujiono W. Purnomo ◽  
...  

The high organic waste content of river water in Demak, north coast of Java, has caused traditional small-scale pond farmers to stop stocking shrimp. This paper examines whether seaweed and mussel will improve the quality of water these farmers use. The effect of Gracilaria verucosa and Perna viridis on the water quality was assessed by measuring the removal rates (RRs) of total organic material (TOM), total ammonia nitrogen (TAN), nitrite, and nitrate. The specific growth rates (SGRs) of seaweed and mussel were also measured. Thirty-six semi-outdoor tanks containing 800 L of brackish water and 7 cm substrate were randomly assigned to four replications of four densities of G. verucosa: 50 (S50), 100 (S100), 150 (S150), and 200 (S200) g m−2, and of P. viridis: 60 (M60), 90 (M90), 120 (M120), and 150 (M150) g m−2. Weekly, the TOM, TAN, nitrite, and nitrate contents were measured, seaweed and mussel weighted; RRs and SGRs were calculated at the end of the study. The effect of densities on the RRs was significant for both seaweed and mussel. P. viridis was more effective in reducing TOM (by 38%) than G. verucosa (7%); G. verucosa achieved higher RRs for TAN, nitrite, and nitrate. At S200, TOM and TAN decreased by 7.4% and 67%, respectively. At M90, TOM and TAN, decreased by 38% and 49%, respectively. However, nitrite increased significantly at S200 and M150. The SGR of seaweed was significantly lower at S200 than that at S150, S100, and S50. The best performing densities were S100 and M90.


2018 ◽  
Vol 7 (3) ◽  
Author(s):  
Fredynanta Saputra ◽  
Sutaryo Sutaryo ◽  
Agung Purnomoadi

Tujuan dari penelitian ini adalah untuk mengetahui pengaruh penggunaan ampas tahu sebagai co-substrat dalam digesti secara anaerob terhadap kecernaan protein, konsentrasi VFA dan total amonia nitrogen. Penelitian dilakukan dengan menggunakan dua buah digester kontinyu dan data dikoleksi selama tiga kali hydraulic retention time (HRT), dimana satu kali HRT setara dengan 25 hari. Data yang diperoleh dibahas dengan metode independent sampel comparison dengan membandingkan variabel hasil pengamatan dari digester satu (tanpa ampas tahu) dan digester dua (penambahan 5% ampas tahu) yang keduanya diencerkan menggunakan air dengan perbandingan 1:1. Hasil dari penelitian ini adalah terdapat adanya perbedaan yang nyata (P<0,05) dari perlakuan yang diterapkan terhadap kecernaan protein, konsentrasi VFA, dan konsentrasi total amonia nitrogen (TAN). Nilai kecernaan protein, konsentrasi VFA dan konsentrasi TAN dari digester 1 dan digester 2 secara berturut turut adalah 36,13% dan 25,71%; 25,39 ml/mol/l dan 11,21 ml/mol/l serta 1959 dan 1675 mg/l. Kesimpulan dari penelitian ini adalah konsentrasi VFA dan TAN yang stabil pada konsentrasi yang relatif rendah pada slurry dari digester 2 dipertengahan dan akhir penelitian mengindikasikan bahwa ampas tahu bisa digunakan sebagai co-subtrat pada feses sapi, namun demikian perlu dilakukan penelitian lebih lanjut untuk mengevaluasi level ampas tahu yang terbaik untuk meningkatkan produksi biogas dari digester biogas berbasis feses sapi.Utilization of Waste from Tofu as Co-Substrate in Biogas ProductionAbstractThe aim of this research was to evaluate the effect of co-substrate of waste of tofu in anaerobic digestion on protein digestibility, VFA concentration, and total ammonia nitrogen. The experiment was performed in two continuously feeding digesters for three hydraulic retention times (HRT) which was a HRT equal to 25 d. The observed data was analysed using independent sample comparison. The treatments were digester 1 as no co-substrat and digester 2 as 5% solid waste from tofu addition which both of them then diluted with tap water at 1:1 ratio. The results of this study showed that there were significant effect (P<0.05) of treatments on protein digestibility, VFA concentration and total ammonia nitrogen. The protein digestibility, VFA concentration and TAN concentration of digester 1 and digester 2 were 36.13 and 25.71%; 25.39 and 11.21 ml/mol/L; 1959 and 1675 mg/L, respectively. As conclusion, a stabil at low concentration of VFA and TAN in the middle and in the end experiment might be used to indicate that waste from tofu is suitable substrate for co-digestion with cow feses, however a further experiment is needed to obtain optimum level of tofu cake to enhance biogas production of digester biogas base on cow feses.•••


2018 ◽  
Vol 34 (6) ◽  
pp. 908-917 ◽  
Author(s):  
Horacio A Aguirre-Villegas ◽  
Mahmoud A Sharara ◽  
Rebecca A Larson

Abstract. The nutrient profile in stored manure can be highly variable due to the solids building up at the bottom of the storage over time as unagitated manure is removed. This variability can lead to under- or over-application of nutrients potentially reducing crop yields or increasing nutrient losses, respectively. Agitation of stored manure is a common practice to re-suspend solids providing a more uniform nutrient consistency for application. This study explores the solids and nutrient variability in stored dairy manure after agitation and the relationship between the number of samples and the quality of the nutrient content estimate. A total of 16 dairy facilities across Wisconsin were sampled in the study. Samples were taken during agitation and analyzed for total solids (TS), total Kjeldahl nitrogen (TKN), total ammonia nitrogen (TAN), total phosphorus (TP), total potassium (TK), and microminerals. Overall, TKN, TAN, and TP contents were more uniform than TS. The mean concentrations (wet basis) from the 16 farms range from 2.45% to 15.28% for TS, 0.17% to 0.53% for TKN, 0.01% to 0.33 for TAN, 0.02 to 0.06 for TP, and 0.11% to 0.31% for TK. This range is mostly attributed to the between-farms variability in manure nutrient content. In addition, 54% of the total variation in the TS content was attributable to within-farm sample variability. These results show that TS was variable on farms whereas TKN, TAN, and TP were variable between farms. A random resampling analysis showed that three samples generate a mean between 20% to 30% of the true experimental mean for TKN and TAN whereas nine samples are required to be in this range for TP. Results show that the improvement achieved by adding more samples than 11 is less than 10%. Keywords: Dairy manure, Manure agitation, Nutrients, Nutrient variability, Sample size.


2021 ◽  
Vol 9 (10) ◽  
pp. 2168
Author(s):  
Er-Meng Yu ◽  
Zhen-Chi Li ◽  
Zhi-Fei Li ◽  
Guang-Jun Wang ◽  
Yun Xia ◽  
...  

Aquaculture is crucial for achieving the FAO’s goal of a world without hunger and malnutrition. Recently, biofilm substratum has been proposed as an effective means to control waste pollution caused by excessive nutrient inputs from aquaculture, but key bacterial communities involved in the remediation remain unclear. Here we reported a freshwater mesocosm study where the addition of biofilm substrata with external carbon effectively controlled the total ammonia nitrogen and improved fish growth. 16S rRNA study and Weighted UniFrac analysis revealed that bacterial compositions were significantly different (999 permutations, p-value < 0.01) between the biofilm-substrata-added and biofilm-substrata-free systems. Planctomycetes were found, as key bacteria benefited from the biofilm substrata addition and exerted the major function of ammonia nitrogen control. Our study demonstrated that the addition of biofilm substrata and an external carbon source favored fish growth and improved the aquaculture environment by the formation of a unique bacteria community.


2018 ◽  
Vol 41 (1) ◽  
pp. 36493
Author(s):  
Weudes Rodrigues Andrade ◽  
Marielly Maria Almeida Moura ◽  
Vicente Ribeiro Rocha Júnior ◽  
Renê Ferreira Costa ◽  
Luiz Henrique Tolentino Santos ◽  
...  

 This study evaluated the effect of increasing levels of leucaena forage in sorghum: forage. In addition to pure sorghum, it was evaluated different levels of inclusion of leucaena (15, 30 and 50%) at the time of ensiling. Forage was ensiled in PVC tubes (100 mm diameter, 500 mm length) under the density of 500 – 600 kg m-3, a total of 20 silos were prepared, which were opened 35 days after ensiling. There was no effect (p > 0.05) of leucaena inclusion levels for pH, water activity (Aw) and total ammonia nitrogen (total NH3-N). There was an increasing linear effect (p < 0.05) for the content of dry matter (DM), crude protein (CP) and lignin that increased from 33.47 to 34.75%, 7.82 to 16.05% and from 7.29 to 9.93%, at the levels from 0 to 50% inclusion of leucaena, respectively. There was a decreasing linear effect (p < 0.05) for neutral detergent fiber corrected for ash and protein (NDFcp) and hemicellulose, which reduced from 56.65 to 48.37% and from 24.07 to 17.67% at the levels of 0 and 50% inclusion, respectively. For the ash content, there was a quadratic effect (p < 0.05), with a maximum at 8.3% with 8.9% inclusion of leucaena. The inclusion of up to 50% leucaena into sorghum silage is recommended, because, in addition to maintaining the fermentation quality, it also improved nutritional quality of sorghum silage.


Paliva ◽  
2021 ◽  
pp. 96-101
Author(s):  
Marie Vojtíšková ◽  
Pavel Jeníček

Anaerobic sludge digestion is an important tool for converting sludge into a renewable fuel - biogas. However, digested sludge can also be used as a fuel, and a fundamental parameter determining the energy value of digested sludge is as effective as possible dewatering. The main aim of the presented study was to evaluate how the anaerobic digestion (AD) technology and post-treatment technology can affect sludge dewaterability. Two technological alternatives of AD were evaluated: mesophilic (MAD) and thermophilic (TAD). In addition, also the effect of postaeration of digested was evaluated. The dewaterability was assessed using two methods based on centrifugation and filter pressing. Finally, the sludge cake concentration of total suspended solids (TSS) was compared. The results showed the difference in sludge dewaterability for the tested sludges: The sludge cake concentration was similar or slightly higher for MAD compared to TAD sludge. Post-aeration of digested sludge increased sludge cake concentration.


FLUIDA ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 65-72
Author(s):  
Robby Sudarman ◽  
Herawati Budiastuti ◽  
Nancy Siti Djenar ◽  
Efniarsi S. Panggalo ◽  
Ajie Nurhasyim

ABSTRAK  Sifat toksik nitrogen amoniak dalam limbah cair berbahaya bagi kehidupan sehingga perlu untuk dihilangkan. Pada penelitian ini penyisihan kadar amoniak yang tinggi dalam limbah cair industri pupuk dilakukan melalui proses nitrifikasi dan denitrifikasi menggunakan Sequencing Batch Reactor (SBR). Dua reaktor SBR digunakan dimana pada reaktor pertama (R1) dilakukan pengadukan dan pada reaktor kedua (R2) dilakukan aerasi. Hasil penelitian menunjukkan bahwa pada pembebanan 0,787 mg amoniak/L/hari dan Hydraulic Retention Time (HRT) 20 hari, efisiensi penyisihan kadar amoniak mampu dicapai pada kisaran 71,26%-90,91% (R1) dan 62,32% -92,21% (R2). Pengukuran pH pada HRT 20 hari berada pada rentang 8,25-8,65 pada R1 dan pH 8,34-8,73 pada R2. Pada HRT 15 hari, efisiensi penyisihan kadar amoniak efluen pada R1 menurun yaitu dari 90,89 % menjadi 86,81% dan pada R2 menurun dari 90,59% menjadi 40,99 %. Pada HRT 15 hari, efisiensi penyisihan kadar amoniak pada R1 lebih baik dibandingkan pada R2 yang disebabkan adanya penambahan aerasi pada R1 di akhir penelitian. Kata kunci: amoniak, limbah cair, industri pupuk, sequencing batch reactor   ABSTRACT  The toxic nature of ammonia nitrogen in liquid waste is dangerous for life, so it needs to be eliminated. In this study, the removal of high ammonia levels in the fertilizer industry wastewater was carried out through a process of nitrification and denitrification using the Sequencing Batch Reactor (SBR). Two SBR reactors were used where the first reactor (R1) was stirred and the second reactor (R2) was aerated. The results showed that at a load of 0.787 mg of ammonia/L/day and 20 days of Hydraulic Retention Time (HRT), the efficiencies of removal of ammonia levels were achieved in the range of 71.26%-90.91% (R1) and 62.32%- 92.21% (R2). The pH measurements at 20 days of HRT were in the range of 8.25-8.65 at R1 and pH 8.34-8.73 at R2. At 15 days of HRT, the effluent ammonia level removal efficiency at R1 decreased from 90.89% to 86.81% and at R2 decreased from 90.59% to 40.99%. At 15 days of HRT, the efficiency of ammonia level removal at R1 was better than that in R2 due to the addition of aeration to R1 at the end of the study. Keywords: ammonia, liquid waste, fertilizer industry, sequencing batch reactor


1982 ◽  
Vol 47 (2) ◽  
pp. 430-445
Author(s):  
Josef Horák ◽  
Zina Valášková

An algorithm has been developed and on a mathematical model analyzed to stabilize the reaction temperature of a batch reactor. The reaction has been a zero-order one and the reactor has been operated in a instable operating point. The action variable is the heat exchange surface whose area is increased if the temperature is above, or decreased if the temperature is below the set point. The following two-point regulators have been studied: An ideal relay, a relay with hysteresis and an asymmetric PD relay. The effect has been discussed of the parameters of the regulators on the quality of regulation. Stability analysis has been made of the stationary switching cycles and the domains of applicability have been determined for individual regulators with respect to the rate of change of the area of heat exchange surface.


Fishes ◽  
2021 ◽  
Vol 6 (2) ◽  
pp. 20
Author(s):  
Jie Cao ◽  
Qi Wang ◽  
Jun Mei ◽  
Jing Xie

This study evaluated the effect of different concentrations (20, 40 and 60 mg/L) of 3-aminobenzoic acid ethyl ester methanesulfonate (MS-222) on the quality changes in turbot during simulated transport in water. The results showed that the ammonia nitrogen content in the transportation water of each sample increased significantly, and the dissolved oxygen level decreased. The dissolved oxygen content in MS-222-treated samples was higher than that of control group (CK) samples. For turbot flesh quality, simulated transport in water led to a decrease in moisture, fat and protein contents in all samples. The MS-222-treated turbot samples showed higher pH values, glycogen contents, springiness and chewiness values and lower lactic acid contents comparing with the CK samples during simulated transport in water. In addition, the fresh and bitter amino acids in the muscle of turbot increased in each treatment group compared to the non-transported fish at the end of the simulated transport. The results showed that MS-222 treatment could retard the turbot transport stress and improve the quality of turbot during simulated transport in water.


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