Continuous desalination with a metal-free redox-mediator

2019 ◽  
Vol 7 (23) ◽  
pp. 13941-13947 ◽  
Author(s):  
Jian Wang ◽  
Qi Zhang ◽  
Fuming Chen ◽  
Xianhua Hou ◽  
Zhilie Tang ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Level ◽  
Removal Efficiency ◽  
Redox Mediator ◽  
High Concentration ◽  
Metal Free ◽  
Batch Treatment ◽  
Single Batch

Metal-free molecular redox-mediated electro-dialytic desalination has been presented, which can directly desalt high concentration of feed (5860 ppm) to the drinking water level (136 ppm) during a continuous single batch treatment. The removal efficiency is up to 97.7%.

Evaluation of a Groundwater Arsenic Treatment Process in Response to Organic Matter Inclusion in Feed Water

2010 ◽  
Vol 5 (3) ◽  
Author(s):  
K. M. Hassan ◽  
K. Fukushi ◽  
F. Nakajima ◽  
K. Yamamoto
Keyword(s):  
Drinking Water ◽  
Organic Matter ◽  
Removal Efficiency ◽  
Treatment Process ◽  
Arsenic Removal ◽  
Feed Water ◽  
High Concentration ◽  
Treatment Unit ◽  
Simple Modification ◽  
Groundwater Arsenic

The contamination of groundwater by sediment-derived arsenic threatens the health of millions of people worldwide and a large number of drinking water treatment units have been employed to prevent this toxicity. This study aims at evaluating the influence of organic matter on groundwater arsenic treatment practice and proposing the modifications related to this issue. The arsenic removal efficiency was found to be decreased even in the presence of a low concentration of organic matter, 5 mg/L as TOC (total organic carbon), and gradually deteriorated with higher concentrations. Nevertheless, a high concentration of bioleached arsenic, above 130 μg/L, was noticed in the inoperative condition of the treatment unit. A simple modification in the treatment process, using an additional iron-matrix layer, substantially increased, 12% more, the arsenic removal efficiency even in the presence of high concentration of organic matter. Strategies were proposed to combat the bioleaching of arsenic in the treatment process. This study revealed that organic matter would significantly impede the arsenic removal process for drinking water and hence safe remediation strategies were imperative.

Optimal operations for groundwater denitrification of drinking water using heterotrophic biological denitrification process

2006 ◽  
Vol 6 (2) ◽  
pp. 125-130
Author(s):  
C.-H. Hung ◽  
K.-H. Tsai ◽  
Y.-K. Su ◽  
C.-M. Liang ◽  
M.-H. Su ◽  
...  
Keyword(s):  
Drinking Water ◽  
Removal Efficiency ◽  
Nitrate Removal ◽  
Drinking Water Treatment ◽  
Nitrate Content ◽  
Source Water ◽  
Nitrogen Gas ◽  
Negative Effect ◽  
Denitrification Process ◽  
Heterotrophic Denitrification

Due to the extensive application of artificial nitrogen-based fertilizers on land, groundwater from the central part of Taiwan faces problems of increasing concentrations of nitrate, which were measured to be well above 30 mg/L all year round. For meeting the 10 mg/L nitrate standard, optimal operations for a heterotrophic denitrification pilot plant designed for drinking water treatment was investigated. Ethanol and phosphate were added for bacteria growing on anthracite to convert nitrate to nitrogen gas. Results showed that presence of high dissolved oxygen (around 4 mg/L) in the source water did not have a significantly negative effect on nitrogen removal. When operated under a C/N ratio of 1.88, which was recommended in the literature, nitrate removal efficiency was measured to be around 70%, sometimes up to 90%. However, the reactor often underwent severe clogging problems. When operated under C/N ratio of 1.0, denitrification efficiency decreased significantly to 30%. Finally, when operated under C/N ratio of 1.5, the nitrate content of the influent was almost completely reduced at the first one-third part of the bioreactor with an overall removal efficiency of 89–91%. Another advantage for operating with a C/N ratio of 1.5 is that only one-third of the biosolids was produced compared to a C/N value of 1.88.

scholarly journals Start-up Strategies for Anaerobic Ammonia Oxidation (Anammox) in In-Situ Nitrogen Removal from Polluted Groundwater in Rare Earth Mining Areas

2021 ◽  
Vol 13 (8) ◽  
pp. 4591
Author(s):  
Shuanglei Huang ◽  
Daishe Wu
Keyword(s):  
Rare Earth ◽  
Low Temperature ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Ex Situ ◽  
High Concentration ◽  
Low Concentration ◽  
Start Up ◽  
Anammox Activity

The tremendous input of ammonium and rare earth element (REE) ions released by the enormous consumption of (NH4)2SO4 in in situ leaching for ion-adsorption RE mining caused serious ground and surface water contamination. Anaerobic ammonium oxidation (anammox) was a sustainable in situ technology that can reduce this nitrogen pollution. In this research, in situ, semi in situ, and ex situ method of inoculation that included low-concentration (0.02 mg·L−1) and high-concentration (0.10 mg·L−1) lanthanum (La)(III) were adopted to explore effective start-up strategies for starting up anammox reactors seeded with activated sludge and anammox sludge. The reactors were refrigerated for 30 days at 4 °C to investigate the effects of La(III) during a period of low-temperature. The results showed that the in situ and semi in situ enrichment strategies with the addition of La(III) at a low-concentration La(III) addition (0.02 mg·L−1) reduced the length of time required to reactivate the sludge until it reached a state of stable anammox activity and high nitrogen removal efficiency by 60–71 days. The addition of La(III) promoted the formation of sludge floc with a compact structure that enabled it to resist the adverse effects of low temperature and so to maintain a high abundance of AnAOB and microbacterial community diversity of sludge during refrigeration period. The addition of La(III) at a high concentration caused the cellular percentage of AnAOB to decrease from 54.60 ± 6.19% to 17.35 ± 6.69% during the enrichment and reduced nitrogen removal efficiency to an unrecoverable level to post-refrigeration.

scholarly journals Response surface methodology approach for the optimisation of adsorption of hydrolysed polyacrylamide from polymer-flooding wastewater onto steel slag: a good option of waste mitigation

2017 ◽  
Vol 76 (4) ◽  
pp. 776-784 ◽  
Author(s):  
Mijia Zhu ◽  
Jun Yao ◽  
Zhonghai Qin ◽  
Luning Lian ◽  
Chi Zhang
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Removal Efficiency ◽  
Contact Time ◽  
Interactive Effect ◽  
Steel Slag ◽  
Oxygen Demand ◽  
Polymer Flooding ◽  
High Concentration ◽  
Adsorbent Dosage

Wastewater produced from polymer flooding in oil production features high viscosity and chemical oxygen demand because of the residue of high-concentration polymer hydrolysed polyacrylamide (HPAM). In this study, steel slag, a waste from steel manufacturing, was studied as a low-cost adsorbent for HPAM in wastewater. Optimisation of HPAM adsorption by steel slag was performed with a central composite design under response surface methodology (RSM). Results showed that the maximum removal efficiency of 89.31% was obtained at an adsorbent dosage of 105.2 g/L, contact time of 95.4 min and pH of 5.6. These data were strongly correlated with the experimental values of the RSM model. Single and interactive effect analysis showed that HPAM removal efficiency increased with increasing adsorbent dosage and contact time. Efficiency increased when pH was increased from 2.6 to 5.6 and subsequently decreased from 5.6 to 9.3. It was observed that removal efficiency significantly increased (from 0% to 86.1%) at the initial stage (from 0 min to 60 min) and increased gradually after 60 min with an adsorbent dosage of 105.2 g/L, pH of 5.6. The adsorption kinetics was well correlated with the pseudo-second-order equation. Removal of HPAM from the studied water samples indicated that steel slag can be utilised for the pre-treatment of polymer-flooding wastewater.

scholarly journals ASSESSMENT OF GROUNDWATER QUALITY FROM INDUSTRIAL AND RESIDENTIAL AREAS OF SANGO OTA, NIGERIA

2021 ◽  
Vol 46 (2) ◽  
Author(s):  
O.A. Oguntade ◽  
V.I. I Fesiokwu ◽  
O. S. Sule
Keyword(s):  
Electrical Conductivity ◽  
Drinking Water ◽  
Water Samples ◽  
Total Suspended Solid ◽  
Industrial Area ◽  
Suspended Solid ◽  
Residential Area ◽  
Total Hardness ◽  
Residential Areas ◽  
High Concentration

High concentration of contaminants in drinking water can affect human health. This study assessed quality of groundwater at industrial and residential areas of Sango Ota, Ogun State. Water samples were collected in triplicates from 8 wells at industrial and residential areas and analyzed for its physicochemical properties. The pH, electrical conductivity, total dissolved solid (TDS), nitrate, sulphate, total suspended solid (TSS), total hardness (TH), iron, zinc, copper, lead, nickel, chromium and cadmium concentrations in the water samples were determined following American Public Health Association (APHA) procedure. Results showed that pH of 50 % of the wells were lower than minimum limit of 6.5 recommended by WHO. Sulphate, TH and iron in the water were significantly (p < 0.05) higher at residential area than industrial area. Electrical conductivity exhibited significant (p < 0.01) correlation with TDS (r = 0.701**) and NO32- (r = 0.922**) at residential area. At the industrial area however, concentration of salts in water samples was highly associated with SO42- (r = 0.864**) and Cd (r = 0.587**). Across locations of groundwater, iron and lead were above allowable WHO limits in drinking water. Cadmium was also above drinking limit at location T4 of the residential area. Consumers of groundwater in the study area are prone to health related challenges of heavy metal toxicity.

scholarly journals Micro-pressure swirl reactor (MPSR) for efficient COD and nitrogen removal of high-concentration wastewater

2020 ◽  
Vol 82 (9) ◽  
pp. 1795-1807 ◽  
Author(s):  
Dejun Bian ◽  
Zebing Nie ◽  
Fan Wang ◽  
Shengshu Ai ◽  
Suiyi Zhu ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Lower Cost ◽  
Batch Reactor ◽  
Oxygen Demand ◽  
Swirl Flow ◽  
High Concentration ◽  
Internal Circulation ◽  
Carbon And Nitrogen ◽  
Pressure Swirl

Abstract A micro-pressure swirl reactor (MPSR) was developed for carbon and nitrogen removal of wastewater, in which dissolved oxygen (DO) gradient and internal circulation could be created by setting the aerators along one side of the reactor, and micro-pressure could be realized by sealing most of the top cap and increasing the outlet water level. In this study, velocity and DO distribution in the reactor was measured, removal performance treating high-concentration wastewater was investigated, and the main functional microorganisms were analyzed. The experiment results indicated that there was stable swirl flow and spatial DO gradient in MPSR. Operated in sequencing batch reactor mode, distinct biological environments spatially and temporally were created. Under the average influent condition of chemical oxygen demand (COD) concentration of 2,884 mg/L and total nitrogen (TN) of 184 mg/L, COD removal efficiency and removal loading was 98% and 1.8 kgCOD/(m3·d) respectively, and TN removal efficiency and removal loading reached up to 90% and 0.11 kgTN/(m3·d) respectively. With efficient utilization of DO and simpler configuration for simultaneous nitrification and denitrification, the MPSR has the potential of treating high-concentration wastewater at lower cost.

scholarly journals Water Level Monitoring System

2019 ◽  
pp. 1282-1287
Author(s):  
Christo Biji ◽  
Vandana C P
Keyword(s):  
Drinking Water ◽  
Water Level ◽  
Monitoring System ◽  
Water Flow ◽  
Rain Water ◽  
Level Monitoring ◽  
Water Level Monitoring

The drinking water is one of the main problems affecting many countries now, in the same way we are not actually using the rain water properly. The misuse of water leads no many problems like uncontrolled water flow etc. Last year 2018 Kerala undergrown a deep flood because of huge rain due to that all the dams in Kerala opened simultaneously. It creates a huge flood in Kerala. Around 370 peoples died in Kerala due to this flood. The main reason is people are not aware of dam opening so the peoples near to the river all are washed off. Most of the dams are not having a digital sensing for water level. All the dams are having only scale measurement so failed to give information about damn opening. Water level monitoring system solves this problem It will give right information about water level in reservoir and it will avoid wastage water in tank.

scholarly journals One-step removal of lead from water using an electricity-free and sustainable membrane filtration

2021 ◽  
Vol 27 (4) ◽  
pp. 166-172
Author(s):  
Junwei Zhang ◽  
Yan Tung Lo ◽  
Hao Guo ◽  
Chuyang Tang
Keyword(s):  
Drinking Water ◽  
Removal Efficiency ◽  
Membrane Filtration ◽  
High Water ◽  
Water Safety ◽  
Drinking Water Contamination ◽  
Emergency Situations ◽  
Drinking Water Safety ◽  
Effective Removal ◽  
Volumetric Loading

Lead (Pb) is a typical contaminant in water with adverse effects on human health. Hong Kong’s incident of drinking water contamination by Pb in 2015 caused severe public concerns regarding drinking water safety. Conventional treatment methods for Pb removal generally require electricity, chemical dosage, and considerable time and space, which significantly restrict their use for rapid water purification under emergency situations. In this study, a polyvinyl alcohol/polyacrylic acid (PVA/PAA) composite nanofibrous membrane was developed for the rapid and effective removal of Pb from water. The PVA/PAA membrane had a high water permeability of 550 L/m2/h/kPa - 710 L/m2/h/kPa, which allowed the filtration to be driven by gravity (e.g. with a water height of 10.0 cm). The membrane showed consistently high removal efficiency of Pb (> 95%) with a volumetric loading up to 3000 L/m2. This high removal efficiency was attributed to the combined effects of complexing and electrostatic attraction between Pb and PAA. An esculent citric acid was used to regenerate the exhausted PVA/PAA membrane. The regenerated membrane maintained its removal efficiency of Pb over a five-cycle filtration. These results imply that the PVA/PAA composite membrane can be repeatedly used in electricity-free filtration devices for rapid elimination of Pb under emergency situations.

Sign in / Sign up

Export Citation Format

Share Document