scholarly journals Ozonation of return activated sludge for disintegration and solubilisation with synthesized titanium oxide as catalyst

2018 ◽  
Vol 34 ◽  
pp. 02009
Author(s):  
S.F.Z. Mohd Sarif ◽  
S.S. Alias ◽  
F. Muhammad Ridwan ◽  
K.S. Ku Salim ◽  
C.Z.A. Abidin ◽  
...  

Ozonation of activated sludge in the present of titanium dioxide (TiO2) as catalyst to enhance the production of hydroxyl radical was evaluated in comparison to the sole ozonation process. In this process, the catalytic ozontion showed improvement in increasing ozone consumption and improving activated sludge disintegration and solubilisation. The reduction of total suspended solid (TSS), volatile suspended solid (VSS) and soluble chemical oxygen demand (SCOD) solubilisation was better in the catalytic ozonation system. Initial pH 7 of activated sludge was found best to disintegrate and solubilise the sludge flocs. However upon additional of sodium hydroxide (NaOH) in pH adjustment enhanced the solubilisation of organic matter from the flocs and cells, making the initial pH 9 is the best condition for activated sludge solubilisation. Yet the initial pH 7 of activated sludge supernatant was the best condition to achieve SCOD solubilisation due to sludge floc disintegration, when it had stronger correlation between TSS reduction and SCOD solubilisation (R2=0.961). Lower amount of catalyst of 100 mgTiO2/gTSS was found to disintegrate and solubilise the activated sludge better with 30.4% TSS reduction and 25.2% SCOD solubilisation efficiency, compared to 200 mgTiO2/gTSS with 21.9% and 17.1% TSS reduction and SCOD solubilisation, respectively.

2019 ◽  
Vol 79 (7) ◽  
pp. 1309-1315
Author(s):  
Hao Li ◽  
Lei Song ◽  
Baohong Han ◽  
Hongwei Song ◽  
Runying Bai ◽  
...  

Abstract This study presents a sulfate radical-based oxidation method for improving municipal sludge dewaterability by combining persulfate and nanoscale zero-valent iron supported on humic acid (nZVI/HA-PS). Sludge dewaterability using persulfate activation with nZVI/HA was assessed for specific resistance to filterability (SRF), time to filter (TTF), settling volume percentage (SV30) and water content (Wc). The influencing factors, such as mass ratios of nZVI to HA, initial pH, PS dosage and nZVI/HA nanocomposite dosage, were investigated. Experimental results indicated that the SRF reduction efficiency of the sludge reached 86.47% using initial concentrations of 1.2 mmol/gVSS PS and 300 mg/L nZVI/HA. The soluble chemical oxygen demand (SCOD) of sludge supernatants increased from 79 mg/L to 710 mg/L under optimum conditioning, indicating that sludge flocs were effectively decomposed. Economic analysis demonstrated that the nZVI/HA-PS conditioning process is a potential method for improving sludge dewaterability.


REAKTOR ◽  
2014 ◽  
Vol 15 (2) ◽  
pp. 73 ◽  
Author(s):  
Lieke Riadi ◽  
Whenny Ferydhiwati ◽  
Liok Dimas Sanjaya Loeman

Limbah industri tekstil di area pinggir kota Surabaya mempunyai karakteristik perbandingan COD dan BOD = 5.57. Limbah jenis ini sulit untuk dibiodegradasi. Studi ini mempelajari tekonologi elektrokoagulasi untuk mengolah limbah tekstil dengan menurunkan intensitas warna, Total Suspended Solid (TSS) dan Chemical Oxygen Demand (COD). Percobaan batch pada suhu kamar dilakukan untuk mempelajari pengaruh pH, jarak elektroda terhadap penurunan warna,TSS dan COD dan membandingkan biaya operasinya jika menggunakan pengolahan kimia.Effisiensi penurunan tertinggi untuk warna (91.96%),  TSS (49.17%), dan COD (29.67%) terjadi pada pH awal 4.0 dan jarak elektroda 2 cm dengan  elektroda Al/Al. Waktu optimum penurunan intensitas warna dalah 10 menit. Laju penurunan COD adalah : -dC/dt = 0.0053 C +0.056 , dengan C adalah konsentrasi COD. Jumlah sludge yang dihasilkan daripengolahan elektrokoagulasi  3.4 % lebih kecil dibandingkan menggunakan bahan kimia. Biaya yang digunakan untuk pengolahan dengan elektrokoagulasi 52.35 % lebih murah dibandingkan jika menggunakan koagulasi dengan bahan kimia ( tawas). Kata kunci : elektrokoagulasi, penurunan warna, penurunan TSS, laju degradasi COD, imbah tekstil Abstract Waste water from textile industry which is located in one suburb of Surabaya city as characteristic which the ratio of COD to BOD was 5.57. This type of waste water is difficult to be biodegraded. This study investigated elektrokoagulasi technology to treat textile waste water by removing color, total suspended solid, and Chemical Oxygen Demand. Batch experiment at room temperature was carried out to study the effect of pH, electrode distance for color, TSS and COD removal. This study also tried to compare the operation cost between elektrokoagulasi and chemical processes. The best removal efficiencies by Al electrodes was 91.96 % for color, 49.17 % for TSS and 29.67 % for COD which were under initial pH 4.0 and electrodes distance 2 cm. The optimum operation time for color removal was  found 10 minutes.The COD degradation rate was - dC/dt = 0.0053 C +0.056, with C= COD concentration. Sludge result from elektrokoagulasi was 3.4 % less than that by chemical treatment.The operation cost for elektrokoagulasi is 52.35 % less than that for chemical coagulation. 


REAKTOR ◽  
2014 ◽  
Vol 15 (1) ◽  
pp. 20 ◽  
Author(s):  
Mohamad Rangga Sururi ◽  
Siti Ainun Saleh ◽  
Amalia Krisna

Limbah industri tekstil di area pinggir kota Surabaya mempunyai karakteristik perbandingan COD dan BOD = 5.57. Limbah jenis ini sulit untuk dibiodegradasi. Studi ini mempelajari tekonologi elektrokoagulasi untuk mengolah limbah tekstil dengan menurunkan intensitas warna, Total Suspended Solid (TSS) dan Chemical Oxygen Demand (COD). Percobaan batch pada suhu kamar dilakukan untuk mempelajari pengaruh pH, jarak elektroda terhadap penurunan warna,TSS dan COD dan membandingkan biaya operasinya jika menggunakan pengolahan kimia.Effisiensi penurunan tertinggi untuk warna (91.96%),  TSS (49.17%), dan COD (29.67%) terjadi pada pH awal 4.0 dan jarak elektroda 2 cm dengan  elektroda Al/Al. Waktu optimum penurunan intensitas warna dalah 10 menit. Laju penurunan COD adalah : -dC/dt = 0.0053 C +0.056 , dengan C adalah konsentrasi COD. Jumlah sludge yang dihasilkan daripengolahan elektrokoagulasi  3.4 % lebih kecil dibandingkan menggunakan bahan kimia. Biaya yang digunakan untuk pengolahan dengan elektrokoagulasi 52.35 % lebih murah dibandingkan jika menggunakan koagulasi dengan bahan kimia ( tawas). Kata kunci : elektrokoagulasi, penurunan warna, penurunan TSS, laju degradasi COD, imbah tekstil Abstract Waste water from textile industry which is located in one suburb of Surabaya city as characteristic which the ratio of COD to BOD was 5.57. This type of waste water is difficult to be biodegraded. This study investigated elektrokoagulasi technology to treat textile waste water by removing color, total suspended solid, and Chemical Oxygen Demand. Batch experiment at room temperature was carried out to study the effect of pH, electrode distance for color, TSS and COD removal. This study also tried to compare the operation cost between elektrokoagulasi and chemical processes. The best removal efficiencies by Al electrodes was 91.96 % for color, 49.17 % for TSS and 29.67 % for COD which were under initial pH 4.0 and electrodes distance 2 cm. The optimum operation time for color removal was  found 10 minutes.The COD degradation rate was - dC/dt = 0.0053 C +0.056, with C= COD concentration. Sludge result from elektrokoagulasi was 3.4 % less than that by chemical treatment.The operation cost for elektrokoagulasi is 52.35 % less than that for chemical coagulation.


2020 ◽  
Vol 15 (3) ◽  
pp. 70-77
Author(s):  
J.D Bala ◽  
F. A Kuta ◽  
N.U Adabara ◽  
O.P Abioye ◽  
H.S Auta ◽  
...  

Water used for washing carcasses of slaughtered animals and slaughter house is referred to as abattoir wastewater. This study was designed to investigate the microorganisms associated with abattoir wastewater and to establish the biodegradation potential of abattoir wastewater microbiota. Isolation of the microbes was carried out using pour plate technique. The total viable count for the microbes’ ranges from 2.5×104 - 4.6×105 cfu/mL. Results revealed that all the physicochemical parameters exceeded the permissible limits (total dissolved solid (TDS) 1748mg/L, total suspended solid (TSS) 176mg/L, biochemical oxygen demand (BOD5) 91 mg/L and chemical oxygen demand (COD) 227 mg/L). Microorganisms isolated include Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis, Bacillus anthracis, Aspergillus niger, A. flavus, Mucor sp, Trichophyton quickeanum and Penicillium sp. Some of the microbes were observed to have biodegradation potential by their ability to grow on mineral salt media (MSM) incorporated with starch, cellulose, crude oil, kerosene and diesel as the sole source of carbon and energy. This study suggests that abattoir wastewater harbors microorganisms that could be hazardous to public health when discharged into the environment untreated hence the need for strict monitoring. These microbes isolated could be employed as agent of bioremediation of wastewaters. Key words: Abattoir; Biodegredation; Isolation; Microbiota; Wastewater


2013 ◽  
Vol 69 (2) ◽  
pp. 269-277 ◽  
Author(s):  
C. Da Ros ◽  
C. Cavinato ◽  
F. Cecchi ◽  
D. Bolzonella

In this study the anaerobic co-digestion of wine lees together with waste activated sludge in mesophilic and thermophilic conditions was tested at pilot scale. Three organic loading rates (OLRs 2.8, 3.3 and 4.5 kgCOD/m3d) and hydraulic retention times (HRTs 21, 19 and 16 days) were applied to the reactors, in order to evaluate the best operational conditions for the maximization of the biogas yields. The addition of lee to sludge determined a higher biogas production: the best yield obtained was 0.40 Nm3biogas/kgCODfed. Because of the high presence of soluble chemical oxygen demand (COD) and polyphenols in wine lees, the best results in terms of yields and process stability were obtained when applying the lowest of the three organic loading rates tested together with mesophilic conditions.


2018 ◽  
Vol 78 (4) ◽  
pp. 764-775 ◽  
Author(s):  
Agnieszka Ryznar-Luty ◽  
Edmund Cibis ◽  
Krzysztof Lutosławski

Abstract The aim of the study was to examine how temperature and the pH influence the progress and efficiency of an aerobic biodegradation process, where major organic pollutants are removed from beet molasses vinasse by a mixed culture of Bacillus bacteria. It was conducted in an aerated bioreactor with a stirring system in four experimental series, each composed of five processes run at temperatures of 27, 36, 45, 54 and 63 °C. In the first and second series, medium pH was not controlled, the initial pH amounted to 6.5 and 8.0, respectively. In the third and fourth series, medium pH was controlled at 6.5 and 8.0, respectively. Under optimal conditions, the pollution load of the vinasse stillage expressed as soluble chemical oxygen demand was removed with an 88.73% efficiency. The bacterial culture assimilated all organic pollutants simultaneously, but the rate of assimilation was different. An exception was the process of betaine assimilation, which intensified only when readily available carbon sources were depleted in the medium. Synthesis and assimilation of organic acids were observed in all experiments. Advantages of the proposed method include: possibility of its use at high temperatures, and no necessity for medium pH adjustment during the process.


Jurnal Ecolab ◽  
2021 ◽  
Vol 15 (2) ◽  
pp. 101-109
Author(s):  
Dewi Ratnaningsih ◽  
◽  
Retno Puji Lestari ◽  
Ernawita Nazir

Kualitas air di suatu wilayah yang merupakan salah satu indikator lingkungan dapat dievaluasi menggunakan parameter fisika, kimia, dan biologi. Indeks Kualitas Air Indonesia (IKA-INA) dapat digunakan untuk menilai kondisi kualitas air secara menyeluruh pada lokasi dan waktu tertentu. IKA-INA dihitung dengan menggunakan sepuluh (10) parameter yaitu pH, Total Dissolved Solid (TDS), Total Suspended Solid (TSS), Dissolved Oxygen (DO), Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), NO3, NH3, Total Phosphate (TP) dan fecal coliform. IKA-INA tersebut merupakan indeks kualitas air yang dapat memberikan informasi secara sederhana. Dalam pemanfaatannya, tidak semua data parameter dalam IKA-INA tersebut dapat terpenuhi karena adanya data tidak valid atau data yang hilang. Kajian ini bertujuan untuk memberi alternatif rumusan IKA-INA dengan parameter yang tidak lengkap atau jika tidak semua data dalam parameters tersebut tersedia. Metode yang digunakan dalam menyusun rumusan adalah dengan melakukan koreksi faktor bobot parameter IKA-INA terhadap parameter yang hilang dan nilai Q (nilai sub-indeks). Setelah itu dilakukan uji coba pada nilai baku mutu air dalam Peraturan Pemerintah No. 22/2021 Lampiran VI serta pada data kualitas air sungai yang mewakili kualitas baik dan buruk. Hasil uji coba menunjukkan bahwa bobot parameter terkoreksi dapat digunakan untuk penanganan parameter yang hilang dalam penilaian kualitas air dengan metode IKA-INA. Hasil IKA-INA dengan parameter hilang yang menggunakan bobot terkoreksi dan hasil IKA-INA dengan parameter lengkap mayoritas memberikan status IKA yang tidak berbeda, kecuali untuk parameter fecal coli dan parameter yang mempunyai kadar jauh berbeda terhadap kondisi air secara keseluruhan.


2018 ◽  
Vol 67 ◽  
pp. 04006 ◽  
Author(s):  
Irfan Aditya ◽  
Sutrasno Kartohardjono

Wastewater generated from the tofu industry usually still contains high organic pollutants that can contaminate the surface water. Therefore, it should be treated properly before it can be disposed to the environment. This study aims to evaluate the combination of coagulationflocculation and ultrafiltration methods in treating the wastewater from tofu industry. Based on the preliminary tests, the wastewater from tofu industry have pH, total dissolved solid (TDS), total suspended solid (TSS), turbidity and chemical oxygen demand (COD) of 3.4, 870 - 1080 mg/L, 370 mg/L, 446 FAU and 7954 mg/L, respectively. The coagulant and membrane used in this study were Poly aluminum chloride (PAC) and the ceramic membrane, respectively. Experimental results showed that the best pH for coagulation-flocculation process is at pH of 7.0, and this pH was then used for ultrafiltration process. The flux of the ultrafiltration membrane increased with increasing the trans membrane pressure due to increasing driving force. The observed parameters such as TSS and turbidity of wastewater decreased drastically after experiencing ultrafiltration process and met the National Environmental Quality Standard. However, the COD of water produced in the ultrafiltration process was still high and did not meet the National Environmental Quality Standard.


2020 ◽  
Vol 32 (4) ◽  
pp. 827-834
Author(s):  
Muhammad Towhid Moula ◽  
Ranjit K. Nath ◽  
Mh. Mosfeka Chowdhury ◽  
Md. Abu Bakar Siddique

Halda is an important river of Bangladesh, is now polluted in different ways through industrial, agricultural, domestic and sewage disposal. Increased anthropogenic activities have increased the potential pollution of the river and excessive pollutants may be toxic to humans and aquatic fauna. Presence of heavy metals in the river water causes perilous impact on the aquatic organisms. Hence, regular monitoring of pollution levels in the river is indispensable. In this study, we discuss about physico-chemical assessments of water quality parameters viz. pH, dissolve oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total solid (TS), total suspended solid (TSS), total dissolved substance (TDS), total alkalinity, turbidity, salinity, electrical conductivity (EC), hardness, chloride and heavy metals in the water of Halda river during rainy and winter seasons, at different points; sources of pollutants in water and their effects given starting from the early research until the current research.


2012 ◽  
Vol 610-613 ◽  
pp. 363-367
Author(s):  
Tipakorn Suwannarat ◽  
Nipon Pisutpaisal ◽  
Siriorn Boonyawanich

The purpose of current study was to examine the ability of electrocoagulation in decreasing chemical oxygen demand (COD) and total suspended solid (TSS) constituted in palm oil mill effluent. Bench-scale batch reactor containing two aluminum or steel plates (10 cm width × 30 cm height with 0.1 cm thickness) serving as electrodes with the interval distance of 3 cm was set up. The wastewater with COD concentration of 68,425 mg L-1 was treated in the reactor under the varied direct currents (0.3-1.3 A) and contact time (30-120 min). Sodium chloride was added to the wastewater to obtain the final concentration of 2 g L-1 (conductivity of 10 ms) prior to being fed into the reactor. The results showed that higher treatment efficiency when the aluminum was used as electrodes compared to the steel. COD removal efficiency was directly proportional to the contact time. The maximum COD and TSS removal observed at 1.3 A current input and 60 min contact time are 74.1 and 77.0%, respectively.


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