scholarly journals Efficient adhesion of bubble on superhydrophobic tapered groove surface

2021 ◽  
Vol 261 ◽  
pp. 02049
Author(s):  
Jianfeng Tang ◽  
Cong Liu ◽  
Shile Feng ◽  
Yahua Liu

Efficient adhesion of gas bubbles in aqueous environments has great application potentials in various gas-related processes, especially in wastewater treatment. In previous research, much attention has been paid to the design of underwater bubbles transport platforms, however, the bubble adhesion abilities of them are explored insufficiently. Herein, we investigated the bubble adhesion abilities of the superhydrophobic V-shaped pattern (SVP) and a designed superhydrophobic tapered groove (STG). It is revealed that the STG exhibits efficient bubble adhesion abilities compared with the SVP, including bubble retention time (t), adhesion volume and holding efficiency (η). In addition, the STG can retain stable adhesion abilities after several adhesion cycles. We believe that these results provide an alternative approach for subaqueous bubble practical applications.

1995 ◽  
Vol 32 (7) ◽  
pp. 135-142
Author(s):  
E. Görgün ◽  
N. Artan ◽  
D. Orhon ◽  
R. Tasli

Effective nitrogen removal is now required to protect water quality in sensitive coastal areas. This involves a much more difficult treatment process than for conventional domestic sewage as wastewater quantity and quality exhibits severe fluctuations in touristic zones. Activated sludge is currently the most widely used wastewater treatment and may be upgraded as a predenitrification system for nitrogen removal. Interpretation of nitrification and denitrification kinetics reveal a number of useful correlations between significant parameters such as sludge age, C/N ratio, hydraulic retention time, total influent COD. Nitrogen removal potential of predenitrification may be optimized by careful evaluation of wastewater character and the kinetic correlations.


1992 ◽  
Vol 26 (3-4) ◽  
pp. 461-472 ◽  
Author(s):  
O. E. Albertson ◽  
P. Hendricks

A 1630 L/s activated sludge plant at Phoenix was limited to an average rate of 1050 L/s and operated, at 400-600 mg/L MLSS and 0.8-1.3 day solids retention time (SRT) due to bulking sludge and limited clarification capacity. Higher SRTs also produced uncontrolled Nocardia foaming and low dissolved oxygen due to partial nitrification. The City retained the services of a team of consultants to resolve these problems as well as to upgrade the plant to provide nitrification and total nitrogen removal. An anoxic selector design was implemented within the existing basin and the clarifiers were modified to improve inlet design and sludge transport. The modified advanced wastewater treatment (AWT) plant operating at 1450 L/s has averaged an effluent of 7.6 mg/L BOD5, 8.2 mg/L TSS, 1.3 mg/L NH4N, 4.1 mg/L NO3N and 2.9 mg/L TP. Oxygen transfer efficiency has increased about 80% in the nitrification-denitrification (NdeN) mode. The cost of modification/upgrading to AWT was approximately $730,000 and a 400 L/s increase in hydraulic capacity was realized. Upgrading costs were $5.63/m3 ($0.02/gal.)


2017 ◽  
Vol 12 (2) ◽  
pp. 95 ◽  
Author(s):  
Rachman Syah ◽  
Mat Fahrur ◽  
Hidayat Suryanto Suwoyo ◽  
Makmur Makmur

Pengolahan air buangan tambak superintensif (TSI) adalah usaha untuk mengurangi beban bahan pencemar yang terkandung di dalam air buangan TSI sehingga aman dan tidak membahayakan saat dibuang ke lingkungan. Penelitian ini bertujuan untuk mengevaluasi desain dan performansi Instalasi Pengolahan Air Limbah (IPAL) dalam memperbaiki kualitas air buangan TSI sebelum dibuang ke badan air. IPAL terdiri atas kolam sedimentasi, dua kolam aerasi, dan satu kolam penampungan. Ke dalam kolam penampungan ditebari ikan mujair serta rumput laut Gracilaria sp. yang dibudidayakan dengan metode long line, berfungsi sebagai biokontrol. Sampel air diambil di bagian inlet IPAL, oulet kolam sedimentasi atau inlet kolam aerasi-1, outlet kolam aerasi-1 atau inlet kolam aerasi-2, outlet kolam aerasi-2 atau inlet kolam penampungan, serta outlet kolam penampungan, setiap dua minggu selama 105 hari pemeliharaan. Parameter yang diukur adalah total padatan tersuspensi (TSS), total amonia nitrogen (TAN), nitrit, nitrat, fosfat, bahan organik terlarut (BOT), dan biological oxygen demand (BOD-5). Spesifikasi teknis IPAL yang diamati meliputi ukuran dan volume IPAL, volume dan waktu tinggal air buangan tambak, dan efisiensi kinerja IPAL, serta rasio volume IPAL dan volume total air tambak. Hasil penelitian menunjukkan bahwa IPAL dapat mengurangi beban bahan pencemar dengan tingkat efisiensi antara 53,1%-99,4%; namun masih diperlukan peningkatan kapasitas dalam mengurangi konsentrasi BOT. IPAL menghasilkan efisiensi yang tinggi terhadap TSS, TAN, nitrit, Total Nitrogen (TN), dan fosfat. Rasio volume IPAL dan volume air tambak 30:70 dengan waktu tinggal minimal lima hari, dapat dijadikan acuan dalam pembangunan IPAL tambak superintensif.A wastewater treatment plant (WTP) in a super-intensive shrimp farm is used to reduce organic matters contained in super-intensive shrimp farm effluent. Through the WTP, the waste water from shrimp facilities can safely and harmlessly be released to the receiving environments. The aims of this study were to evaluate the design and performance of a WTP in reconditioning waste water released from a super-intensive shrimp farm prior to release to water bodies. The WTP was made of a series of sedimentation pond, two aeration ponds, and one reservoir or equalitation pond. The tilapia fish and seaweed, Gracilaria sp., were stocked in the equalitation pond where the seaweed was cultured using long line method; these organisms were used as bio-control. Water samples were collected fortnightly during 105 days of culturing duration from the WTP inlet, outlet of sedimentation pond or at inlet of the first aeration pond; outlet of the first aeration pond or inlet of the second aeration pond, outlet of the second aeration pond or inlet of equalitation pond and the outlet of equalitation pond. The measured variables were total suspended solid (TSS), total ammonia nitrogen (TAN), nitrite, nitrate, phosphate, total organic matters (TOM), and five days biological oxygen demand (BOD5). The evaluated technical performances of the plant were its size and volume; volume and retention time of effluent, efficiency of WTP performance and volume ratios of the WTP and total volume of shrimp pond. The results of the study indicated that the WTP was able to reduce concentrations of nutrients and solids in effluent by 53.1%-99.4% of efficiency. However, its capacity need to be increased due to reducing concentrations of TOM. The WTP was highly efficient in reducing the concentrations of TSS, TAN, nitrite, total N, and phosphate. The volume ratios between the plant and pond waters were 30:70 with minimum retention time five which days could be proposed for wastewater treatment pond for super-intensive shrimp ponds.


REAKTOR ◽  
2019 ◽  
Vol 19 (1) ◽  
pp. 18-25
Author(s):  
Ariani Dwi Astuti ◽  
Dewi Intania Ayu

Tofu which is made by grinding soy bean, generates huge amount of wastewater and thus considered as one of the most polluted food-industrial effluent owing to its high values of organic contents. The small industries of tofu preparation process release the wastewater directly into the water body without being treated first. Prior to discharge this wastewater into the waterbody, the wastewater must be treated to reduce the possibility of negative impact and the contamination of the waterbody. For these small industries, the best alternative of wastewater treatment is one which has the following criteria: easy in operation, low cost operation, low volumes of sludge produced, and can be used in high concentration wastewater. In this research, bioreactor anaerobic-aerobic with media bioball is used. The highest removal efficiency of COD took place in anaerobic zones. Bioreactors were operated with the variations of retention time at 24 hours, 18 hours, and 12 hours. The COD removal efficiency for Hydraulic Retention Time (HRT) of 24 hours, 18 hours and 12 hours were found 90.3% (organic loading rate is 15.1 kg COD/m3.day), 84.4% and 76.3% respectively. The experiment showed that the longer of the hydraulic retention time (HRT), the higher the removal efficiency could be achieved. These occurred because a longer HRT will extend the contact time between wastewater and microorganisms attached. Therefore, microorganisms have a longer time to degrade organic matter in wastewater. Although the removal efficiency in these three-HRT was found high, the effluent of the reactor was still above the effluent standard based on regulation of Ministry of Environmental Permen LH No. 5/2014. Kinetics using Eckenfelder Equation results R2 equal to 0.9991, n equal to 0.293 and K equivalent to 7.3577 mg/L. Keywords: tofu wastewater, anaerobe, aerobe, bioball, wastewater, treatment, attached growth


Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 987 ◽  
Author(s):  
Yang Wu ◽  
Yongzhi Zhang ◽  
Junping Ju ◽  
Hao Yan ◽  
Xiaoyu Huang ◽  
...  

Halloysite nanotubes (HNTs), novel 1D natural materials with a unique tubular nanostructure, large aspect ratio, biocompatibility, and high mechanical strength, are promising nanofillers to improve the properties of polymers. In this review, we summarize the recent progress toward the development of polysaccharide-HNTs composites, paying attention to the main existence forms and wastewater treatment application particularly. The purification of HNTs and fabrication of the composites are discussed first. Polysaccharides, such as alginate, chitosan, starch, and cellulose, reinforced with HNTs show improved mechanical, thermal, and swelling properties. Finally, we summarize the unique characteristics of polysaccharide-HNTs composites and review the recent development of the practical applications.


2018 ◽  
Vol 85 (3) ◽  
pp. 379-383 ◽  
Author(s):  
Peter Leonard ◽  
Emma Tarpey ◽  
William Finnegan ◽  
Xinmin Zhan

This Research Communication describes an investigation into the viability of an Intermittently Aerated Sequencing Batch Reactor (IASBR) for the treatment of dairy processing wastewater at laboratory-scale. A number of operational parameters have been varied and the effect has been monitored in order to determine optimal conditions for maximising removal efficiencies. These operational parameters include Hydraulic Retention Time (HRT), Solids Retention Time (SRT), aeration rate and cycle length. Real dairy processing wastewater and synthetic wastewater have been treated using three laboratory-scale IASBR units in a temperature controlled room. When the operational conditions were established, the units were seeded using sludge from a municipal wastewater treatment plant for the first experiment, and sludge from a dairy processing factory for the second and third experiment. In experiment three, the reactors were fed on real wastewater from the wastewater treatment plant at this dairy processing factory. These laboratory-scale systems will be used to demonstrate over time that the IASBR system is a consistent, viable option for treatment of dairy processing wastewater in this sector. In this study, the capacity of a biological system to remove both nitrogen and phosphorus within one reactor will be demonstrated. The initial operational parameters for a pilot-scale IASBR system will be derived from the results of the study.


2007 ◽  
Vol 55 (11) ◽  
pp. 165-171 ◽  
Author(s):  
M. Medina ◽  
U. Neis

Algal incorporation into the biomass is important in an innovative wastewater treatment that exploits the symbiosis between bacterial activated sludge and microalgae (Chlorella vulgaris sp. Hamburg). It allows a good and easy algae separation by means of clarification. The effect of process parameters food to microorganisms ratio (F/M) and hydraulic retention time (HRT) on the process performance, evaluated by settleability, microalgae incorporation to biomass and nutrient removal, was studied. HRT hinted at a significant influence in the growth rate of algae, while F/M turned out to be important for stability when algae are incorporated into the biomass. This parameter also affects the total nitrogen removal of the treatment. Stable flocs with incorporated algae and supernatants with low free swimming algae concentrations were obtained at high HRT and low F/M values.


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