scholarly journals Effect of Volume Loading Rate and C/N on Ship Domestic Sewage Treatment by Two Membrane Bioreactors

2019 ◽  
Vol 64 (3) ◽  
pp. 328-339
Author(s):  
Yuhang Cai ◽  
Asad A. Zaidi ◽  
Peiqi Sun ◽  
Yue Shi ◽  
Kun Zhang ◽  
...  

Design of ship sewage treatment systems that not only satisfy the use of small space on board but also meets International Maritime Organisation (IMO) latest emission standards is still a challenging problem for ship industry. This study provides a comparative disquisition between two different MBR reactors i.e, air-lift multilevel circulation membrane reactor (AMCMBR) and anaerobic/anoxic/aerobic membrane reactor (AOA-MBR) for domestic sewage treatment. The influence of pollutants volume loading rate (VLR) and C/N on effluent chemical oxygen demand (COD), ammonium nitrogen (NH4+-N) and TN for marine domestic sewage was analyzed. The results revealed that AMCMBR showed better removal efficiencies for COD and TN than AOA-MBR. The volume of AMCMBR was only half of the AOA-MBR. In addition, high average value of mixed liquor volatile suspended solids (MLVSS)/mixed liquid suspended solids (MLSS) (i.e. 0.75) of AMCMBR indicated high biomass and good pollutants removal achieved by this reactor. An interesting phenomenon was found in the study regarding Urease activity for the two reactors. Urease activity for AMCMBR in different working conditions all exceeded AOA-MBR and there exist no clear difference of NR activities between AMCMBR and AOA-MBR except for low C/N ratio (i.e. 6 and 4). This phenomenon proved that AMCMBR has a greater performance for treating ship domestic wastewater.

2013 ◽  
Vol 2013 ◽  
pp. 1-6
Author(s):  
Dong Sheng Shen ◽  
Bao Cheng Huang ◽  
Hua Jun Feng ◽  
Bo Zhao ◽  
Jiang Ming Zhao ◽  
...  

A novel decentralised sewage treatment reactor (DSTR) for treating domestic sewage in rural areas was designed and investigated. The reactor was started aerobically after inoculation with biomass; the amount of initial mixed liquid suspended solids was 1.5 g/L. Oxygen was supplied to the reactor and the dissolved oxygen concentration was maintained at 1.3 ± 0.2 mg/L. The pollutant removal performance was investigated, and the average removal efficiencies of total chemical oxygen demand (TCOD),NH4+-N, suspended solids, and turbidity were 76%, 77.15%, 84.17%, and 83.93%, respectively. The DSTR exhibited good performance compared with the traditional activated sludge (AS) reactor. The resistance to impact load of the DSTR was superior to that of the AS reactor during surface load experiments. During the 120 days of operation, no sludge bulking was observed. The DSTR effluentNH4+-Nand TCOD levels were a little higher than those for the AS reactor, but the disparity was not major.


2004 ◽  
Vol 49 (5-6) ◽  
pp. 281-288 ◽  
Author(s):  
S.J. Kim ◽  
P.Y. Yang

A two-stage entrapped mixed microbial cell (2SEMMC) process which separates nitrification and denitrification phases by the installation of the anoxic and oxic EMMC reactors packed with EMMC carriers was operated with 6, 4, 3, and 2 hours of hydraulic retention time (HRT) using simulated domestic wastewater. The activated sludge was immobilized using cellulose acetate for the EMMC carriers. Similar soluble chemical oxygen demand (SCOD) removal efficiencies of 90-97% were observed for all HRTs (SCOD loading rate of 0.84-2.30 g/L/d) applied. In order to achieve more than 80 % of TN removal efficiency, the HRT should be maintained higher than 4 hours (less than 0.24 g/L/d of TN loading rate). Denitrification was a rate-limiting step which controlled overall TN removal efficiency at TN loading rate of 0.15-0.31 g/L/d although nitrification efficiencies achieved 97-99 %. The effluent TSS of less than 25 mg/L in the 2SEMMC process was maintained at the SCOD loading rate of less than 1.23 g/L/d with back-washing intervals of 5 and 10 days in the anoxic and oxic EMMC reactors, respectively. The minimum HRT of 4 hours is required for high removal efficiencies of organics (average 95.6 %) and nitrogen (average 80.5 %) in the 2SEMMC process with 3 times of recirculation ratio.


2016 ◽  
Vol 74 (7) ◽  
pp. 1509-1517 ◽  
Author(s):  
Linan Zhu ◽  
Hailing He ◽  
Chunli Wang

The hybrid membrane bioreactor (HMBR) has been applied in ship domestic sewage treatment under high volumetric loading for ship space saving. The mechanism and influence factors on the efficiency, including hydraulic retention time (HRT), dissolved oxygen (DO) of chemical oxygen demand (COD) removal were investigated. The HMBR's average COD removal rate was up to 95.13% on volumetric loading of 2.4 kgCOD/(m3•d) and the COD concentration in the effluent was 48.5 mg/L, far below the International Maritime Organization (IMO) discharge standard of 125 mg/L. DO had a more remarkable effect on the COD removal efficiency than HRT. In addition, HMBR revealed an excellent capability of resisting organics loading impact. Within the range of volumetric loading of 0.72 to 4.8 kg COD/(m3•d), the effluent COD concentration satisfied the discharge requirement of IMO. It was found that the organics degradation in the aeration tank followed the first-order reaction, with obtained kinetic parameters of vmax (2.79 d−1) and Ks (395 mg/L). The original finding of this study had shown the effectiveness of HMBR in organic contaminant degradation at high substrate concentration, which can be used as guidance in the full scale of the design, operation and maintenance of ship domestic sewage treatment devices.


2014 ◽  
Vol 34 (4) ◽  
pp. 770-779 ◽  
Author(s):  
Fábio Orssatto ◽  
Marcio A. Vilas Boas ◽  
Ricardo Nagamine ◽  
Miguel A. Uribe-Opazo

The current study used statistical methods of quality control to evaluate the performance of a sewage treatment station. The concerned station is located in Cascavel city, Paraná State. The evaluated parameters were hydrogenionic potential, settleable solids, total suspended solids, chemical oxygen demand and biochemical oxygen demand in five days. Statistical analysis was performed through Shewhart control charts and process capability ratio. According to Shewhart charts, only the BOD(5.20) variable was under statistical control. Through capability ratios, we observed that except for pH the sewage treatment station is not capable to produce effluents under characteristics that fulfill specifications or standard launching required by environmental legislation.


2021 ◽  
Author(s):  
Vanitha Thammaiah ◽  
Manjunatha Hebbara ◽  
Manjunatha Mudukapla Virupakshappa

Abstract An experiment with different filterbeds and macrophytes was carried-out to study their phytoremediation capacity on the efficiency of domestic wastewater treatment through constructed wetland (CW) during November to March, 2017-18 at University of Agricultural Sciences, Dharwad campus, Karnataka, India. Twenty treatment combinations involving five types of filterbeds (FB-1: gravel, FB-2: gravel-sand-gravel, FB-3: gavel-sand-brick-gravel, FB-4: gravel-sand-charcoal-gravel and FB-5: gravel-sand-(charcoal+brick)-gravel) and four macrophytes (MP-1: Typha latifolia, MP-2: Brachiaria mutica, MP-3: Canna indica and MP-4: Phragmites sps.) were evaluated for treating domestic wastewater. After 120 days from start, across treatment combinations, water electrical conductivity (EC), total dissolved and suspended solids (TDS-TSS), biological oxygen demand (BOD), chemical oxygen demand (COD), sodium, sodium adsorption ratio (SAR), residual sodium carbonate (RSC), bicarbonates, total nitrogen-phosphorus-potassium (N-P-K) and boron (B) were reduced by more than 40 per cent due to wetland treatment. The system enhanced the mineralization of organic nitrogen to ammoniacal nitrogen (NH4+-N) and nitrate nitrogen (NO3-N) fractions. Among filterbeds, Type-5 caused higher reduction in pH, EC, BOD, COD and Organic-N while, Type-4 proved efficient in removing total solids and lowering pH in the sewage effluent. The Type-3 filterbed removed more suspended solids, potassium and ammoniacal nitrogen. Among the macrophytes, Brachiaria (paragrass) removed more nitrogen and potassium while, Phragmites removed more nitrogen, phosphorus and boron. The flexibility of implementation allows the CW to be adapted to different sites with different configurations, being suitable as main, secondary or tertiary treatment stage.


2001 ◽  
Vol 43 (12) ◽  
pp. 191-193 ◽  
Author(s):  
M. Kaneko ◽  
T. Nambu ◽  
M. Tokoro

“Johkasou” is a small sewage treatment apparatus commonly used in Japan which can effectively treat domestic wastewater in places where a public sewage system is difficult to supply. The behaviour of enterohaemorrhagic E. coli 0157 and Salmonella enteritidis in a “Johkasou” was studied. Their reduction rates depended significantly on the water temperature in the “Johkasou” with minimal decrease in numbers at 10°C within 48 h. The reduction rates increased at 20°C and 30°C where 4 log reduction could be expected. The reduction rates were influenced by the BOD of the solutions that contained the pathogens with the lower the BOD the higher the reduction rate. The reduction rates were about the same between both pathogens. The result showed that it was necessary to disinfect the effluent as some pathogens can pass through the apparatus when some users of the apparatus excrete pathogens.


2018 ◽  
Vol 78 (9) ◽  
pp. 1879-1892 ◽  
Author(s):  
Md Khalekuzzaman ◽  
Muhammed Alamgir ◽  
Mehedi Hasan ◽  
Md Nahid Hasan

Abstract In this research, a hybrid anaerobic baffled reactor (HABR) configuration was proposed consisting of a front sedimentation chamber and four regular baffled chambers followed by two floated filter media chambers for the treatment of domestic wastewater. Performance comparison of uninsulated and insulated HABRs was carried out operating at warm temperature (18.6–37.6 °C) under variable HRTs (30 h and 20 h). The study suggests that almost similar chemical oxygen demand (91% vs 88%), total suspended solids (90% vs 95%), turbidity (98% vs 97%), and volatile suspended solids (90% vs 93%) removal efficiencies were obtained for uninsulated and insulated HABRs. Higher removal of total nitrogen (TN) of 41%, NH4+-N of 44%, and NO3−-N of 91% were achieved by the insulated HABR compared to TN of 37%, NH4+-N of 36%, and NO3−-N of 84% by the uninsulated HABR, whereas lower PO43− removal efficiency of 17% was found in the insulated HABR compared to 24% in the uninsulated HABR. This indicated insulation increased nitrogen removal efficiencies by 4% for TN, 8% for NH4+-N and 7% for NO3−-N, but decreased PO43−removal efficiency by 7%.


2014 ◽  
Vol 69 (7) ◽  
pp. 1410-1418 ◽  
Author(s):  
Weijie Guo ◽  
Zhu Li ◽  
Shuiping Cheng ◽  
Wei Liang ◽  
Feng He ◽  
...  

To examine the performance of a constructed wetland system on stormwater runoff and domestic sewage (SRS) treatment in central east China, two parallel pilot-scale integrated constructed wetland (ICW) systems were operated for one year. Each ICW consisted of a down-flow bed, an up-flow bed and a horizontal subsurface flow bed. The average removal rates of chemical oxygen demand (CODCr), total suspended solids (TSS), ammonia (NH4+-N), total nitrogen (TN) and total phosphorus (TP) were 63.6, 91.9, 38.7, 43.0 and 70.0%, respectively, and the corresponding amounts of pollutant retention were approximately 368.3, 284.9, 23.2, 44.6 and 5.9 g m−2 yr−1, respectively. High hydraulic loading rate (HLR) of 200 mm/d and low water temperatures (<15 °C) resulted in significant decrease in removals for TP and NH4+-N, but had no significant effects on removals of COD and TSS. These results indicated that the operation of this ICW at higher HLR (200 mm/d) might be effective and feasible for TSS and COD removal, but for acceptable removal efficiencies of nitrogen and phosphorus it should be operated at lower HLR (100 mm/d). This kind of ICW could be employed as an effective technique for SRS treatment.


2021 ◽  
Vol 83 (5) ◽  
pp. 35-44
Author(s):  
Z. M. Hanafiah ◽  
W. H. M. W. Mohtar ◽  
N. A. Bachi' ◽  
N. A. Abdullah ◽  
M. Z. Abdullah ◽  
...  

Sewage treatment plants (STP) in Malaysia are designed to treat a load of contaminants according to the level of concentration for chemical oxygen demand (COD) and nitrogen ammonia (NH3-N) of 250 mg/L and 30 mg/L, respectively. However, studies show that the organic load of Malaysian wastewater is low and even temporarily fluctuates resulting in the low effectiveness of treatment especially in ammonia removal and consequently cause effluents that do not undergo proper treatment to be released into the environment. Therefore, this study aims to identify concentrations of COD and NH3-N in the influent of urban domestic wastewater along with other physico-chemical characteristics. Two locations of the STP were chosen based on the urban area with different catchment sizes for a population equivalent (PE) 60,000 for the first STP (LRK#1), and 150,000 for the second STP (LRK#2). These parameters include pH, temperature, conductivity, turbidity, total suspended solids (TSS), nitrogen nitrate (NO3-N), total Kjeldahl nitrogen (TKN) as well as heavy metals such as Cadmium (Cd), Chromium (Cr), Copper (Cu), Nickel (Ni), Lead (Pb), and Zinc (Zn). The sampling and analysis methods used the guidelines recommended in the American Public Health Association (APHA). The results give the highest average COD concentrations for the LRK#1 and LRK#2 are 180.5 mg/L and 380.9 mg/L, respectively. The highest NH3-N concentrations were 33.53 mg/L for LRK#1 and 31.63 mg/L for LRK#2. Overall, the wastewater physico-chemical characteristics of both treatment plants show wastewater in the medium and low concentration categories.


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