scholarly journals Beyond signal quality: The value of unmaintained pH, dissolved oxygen, and oxidation-reduction potential sensors for remote performance monitoring of on-site sequencing batch reactors

2018 ◽  
Author(s):  
Mariane Yvonne Schneider ◽  
Juan Pablo Carbajal ◽  
Viviane Furrer ◽  
Bettina Sterkele ◽  
Max Maurer ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Reduction Potential ◽  
Batch Reactor ◽  
Soft Sensor ◽  
Small Scale ◽  
Ammonium Oxidation ◽  
Soft Sensors ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Using Data

Sensor maintenance is time-consuming and is a bottleneck for monitoring on-site wastewater treatment systems. Hence, we compare maintained and unmaintained pH, dissolved oxygen (DO), and oxidation-reduction potential (ORP) sensors to monitor the biological performance of a small-scale sequencing batch reactor (SBR). We created soft sensors using engineered features: ammonium valley for pH, oxidation ramp for DO, and nitrite ramp for the ORP. We found that the pH soft sensors are able to reliably identify the completion of ammonium oxidation in the SBR’s effluent even without sensor maintenance for over a year. In contrast, the DO soft sensor using data from a maintained sensor showed slightly better detection performance than that using data from unmaintained sensors, as the DO soft sensor using maintained data is much less sensitive to the optimisation of cut-off frequency and slope tolerance than the soft sensor using unmaintained data. The nitrite ramp provided no useful information on the state of nitrite oxidation, so no comparison of maintained and unmaintained ORP sensors was possible in this case. We identified two hurdles when designing soft sensors for unmaintained sensors: i) Sensors’ type- and design-specific deterioration affects performance. ii) Feature engineering for soft sensors is sensor type specific, and the outcome is strongly influenced by operational parameters such as the aeration rate. In summary, we provide soft sensors that allow the performance of unstaffed small-scale SBRs to be monitored with unmaintained sensors and therefore the maintenance and reliability of OST systems to be optimised.

scholarly journals KEMATIAN MASSAL IKAN DAN SEBARAN PARAMETER KUALITAS AIR DI TELUK JAKARTA

2017 ◽  
Vol 8 (2) ◽  
pp. 77 ◽  
Author(s):  
Masayu Rahmia Anwar Putri ◽  
Sri Turni Hartati ◽  
Fayakun Satria
Keyword(s):  
Dissolved Oxygen ◽  
Biochemical Oxygen Demand ◽  
Reduction Potential ◽  
Oxygen Demand ◽  
Total Suspended Solid ◽  
Economic Loss ◽  
Suspended Solid ◽  
Water Parameters ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential

Berbagai jenis ikan, dengan bobot total lebih dari 650 kg ditemukan mati di pesisir Pantai Ancol tanggal 30 November 2015, diantaranya yang dominan adalah gulamah (Scianidae). Kematian ikan yang sering terjadi akan menyebabkan kerugian ekonomi yang signifikan. Identifikasi faktor penyebab terjadinya peristiwa ini sangat penting untuk diketahui dalam rangka pengelolaan populasi ikan dan penyusunan tindakan pencegahan sehingga bisa mengurangi frekuensi dan besarnya tingkat kematian ikan. Penelitian ini bertujuan untuk mengetahui sebaran spasial beberapa parameter kualitas airguna mengidentifikasi faktor penyebab kematian masal ikan di Teluk Jakarta yang terjadi pada tanggal 30 November 2015. Pengamatan dilakukan pada tanggal 1-3 Desember 2015 di 14 stasiun penelitian mencakup14 parameter fisika, kimia dan biologi perairan. Sebaran spasial beberapa parameter perairan dipetakan dengan menggunakan software ArcGIS 9.3. Parameter perairan (kedalaman, kecerahan, suhu air, pH, oksigen terlarut dan ORP (Oxidation Reduction Potential)) diukur secara insitu dan contoh air permukaan diambil untuk pengamatan plankton serta parameter kimia air di laboratorium (nitrat, fosfat, ammonia, biochemical oxygen demand, total suspended solid, sulfide dan bahan organik terlarut). Berdasarkan analisa dari 14 parameter fisika, kimia dan biologi perairan diketahui faktor penyebab kematian masal ikan di Teluk Jakarta pada 30 November 2015 disebabkan karena rendahnya kandungan oksigen terlarut(0,07mg/l pada lokasi pusat kematian ikan),kadar nutrien yang berlebihan(nitrat,0,003-0,389 mg/l dan fosfat 0,811-1,653 mg/l,)dan tingginya konsentrasi ammonia yang merupakan gas beracun dan berbau (0,227-1,944 mg/l). On November 30th, 2015, more than 650 kg fishes found dead in the coast of Ancol. The identification of its causes is very vital to develop mitigation for managing fish population and preventing economic loss. This study aims to examine several waters parameters to identify the factors causing mass deaths of fish. The study was conducted on 1-3 December 2015 in Jakarta Bay by analyzing 14 parameters of physical, chemical and biological aspect. Spatial distribution of water parameters mapped using ArcGIS 9.3 software. Some water parameters were measured in situ (depth, brightness, water temperature,pH, dissolved oxygen and ORP (oxidation reduction potential) while surface water samples were taken and analyzed in the laboratory (Nitrate, phosphate, ammonia, biochemical oxygen demand. The result showed that a mass fish kills in Jakarta Bay on 30 November 2015 due to low dissolved oxygen content, release of toxic gas into the water, excessive nutrient and high ammonia.

scholarly journals Do Wet-Dry Ratio and Fe-Mn System Affect Oxidation-Reduction Potential Nonlinearly in the Subsurface Wastewater Infiltration Systems?

2018 ◽  
Vol 15 (12) ◽  
pp. 2790
Author(s):  
Xiaorong Zhang ◽  
Haibo Li ◽  
Yinghua Li ◽  
Fei Guo ◽  
Zhongxin Yang ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Water Content ◽  
Reduction Potential ◽  
Initial Period ◽  
Dry Period ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Hypoxic Environment ◽  
Hydraulic Load ◽  
On Line

To understand characteristics of on-line oxidation-reduction potential (ORP) in a subsurface wastewater infiltration system (SWIS) under different intermittent influent conditions, ORP among five matrix depths at wet-dry ratios (Rwds) of 2:1, 1:1 and 1:2 with a hydraulic load of 0.10 m3·(m2·d)−1 were monitored. Results showed that the optimal Rwd for the SWIS was 1:1. In that case, ORP at 40 and 65 cm depths changed significantly, by 529 mV and 261 mV, respectively, from the inflow period to the dry period, which was conducive to the recovery of the oxidation environment. It was concluded that ORP varied nonlinearly in strongly aerobic and hypoxic environment. Wastewater was fed into the SWIS at 80 cm and dissolved oxygen diffused at the initial period of one cycle. As a consequence, ORP at 65 cm increased with water content increasing. However, ORP at 40 and 95 cm displayed inverse trends. Moreover, results showed that ORP decreased with Fe2+ and Mn2+ increasing under aerobic conditions (p < 0.05) because Fe2+ and Mn2+ moved with wastewater flow. Effluent met reuse requirements and no clogging was found in the SWIS during the operation.

scholarly journals THE OXIDATION-REDUCTION POTENTIAL OF THE LUCIFERIN-OXYLUCIFERIN SYSTEM

1927 ◽  
Vol 10 (3) ◽  
pp. 385-393 ◽  
Author(s):  
E. Newton Harvey
Keyword(s):  
Dissolved Oxygen ◽  
Reduction Potential ◽  
Water Solution ◽  
Considerable Reduction ◽  
Reduction Potentials ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Apparent Reduction ◽  
Reduction And Oxidation

The oxidation-reduction potential of the Cypridina luciferin-oxyluciferin system determined by a method of "bracketing" lies somewhere between that of anthraquinone 2-6-di Na sulfonate (Eo' at pH of 7.7 = –.22) which reduces luciferin, and quinhydrone (Eo' at pH of 7.7 = +.24), which oxidizes luciferin. Systems having an Eo' value between –.22 and +.24 volt neither reduce oxyluciferin nor oxidize luciferin. If the luciferin-oxyluciferin system were truly reversible considerable reduction and oxidation should occur between –.22 and +.24. The system appears to be an irreversible one, with both "apparent oxidation" and "apparent reduction potentials" in Conant's sense. Hydrosulfites, sulfides, CrCl2, TiCl3, and nascent hydrogen reduce oxyluciferin readily in absence of oxygen but without luminescence. Luminescence only appears in water solution if luciferin is oxidized by dissolved oxygen in presence of luciferase. Rapid oxidation of luciferin by oxygen without luciferase or oxidation by K3Fe(CN)6 in presence of luciferase but without oxygen never gives luminescence.

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