scholarly journals Feasibility of on-site grey-water reuse for toilet flushing in China

2016 ◽  
Vol 8 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Jie Zhu ◽  
Martin Wagner ◽  
Peter Cornel ◽  
Hongbin Chen ◽  
Xiaohu Dai
Keyword(s):  
Water Reuse ◽  
Municipal Wastewater ◽  
Reclaimed Water ◽  
Oxygen Demand ◽  
Biological Processes ◽  
High Concentration ◽  
Domestic Water ◽  
Grey Water ◽  
Toilet Flushing ◽  
Grey Water Reuse

Abstract Although the total reuse rate of municipal wastewater was 8.8% in China in 2012, water crisis is forcing China to increasingly develop water reuse. Urban reuse is comparatively poor and has significant potential to be promoted in China. It is a sensitive matter whether to include kitchen wastewater in grey-water reuse in water-deficient areas when kitchen wastewater accounts for a large proportion of total domestic water consumption. Concentrations of chemical oxygen demand, BOD5 (biochemical oxygen demand), and total organic carbon in kitchen wastewater are comparatively lower in China than in other countries, but a high concentration of nitrogen from washing tableware and rice makes it difficult to meet nitrogen requirements in Chinese guidelines. Whether kitchen wastewater should be included in grey-water reuse in China needs further study. Aerobic biological processes combined with physical filtration and/or disinfection is preferred in grey-water treatment, and how to balance the investment and treatment costs with reuse criteria still needs to be researched further. The promotion of reclaimed water for toilet flushing faces resistance in China. The necessity and effectiveness of existing restrictions in water reuse guidelines for toilet flushing in China are in doubt and need further discussion.

Assessing the potential of a UV-based AOP for treating high-salinity municipal wastewater reverse osmosis concentrate

2013 ◽  
Vol 68 (9) ◽  
pp. 1994-1999 ◽  
Author(s):  
Muhammad Umar ◽  
Felicity Roddick ◽  
Linhua Fan
Keyword(s):  
Reverse Osmosis ◽  
Municipal Wastewater ◽  
High Salinity ◽  
Oxygen Demand ◽  
Process Efficiency ◽  
Secondary Effluent ◽  
Biological Processes ◽  
Fluorescence Excitation ◽  
H2o2 Treatment ◽  
Humic Compounds

The UVC/H2O2 process was studied at laboratory scale for the treatment of one moderate (conductivity ∼8 mS/cm) and two high salinity (∼23 mS/cm) municipal wastewater reverse osmosis concentrate (ROC) samples with varying organic and inorganic characteristics. The process efficiency was characterized in terms of reduction of dissolved organic carbon (DOC), chemical oxygen demand (COD), colour and absorbance at 254 nm (A254), and the improvement of biodegradability. The reduction of colour and A254 was significantly greater than for DOC and COD for all samples due to the greater breakdown of humic compounds, as confirmed by fluorescence excitation-emission matrix spectra. Fairly small differences in the reduction of DOC (26–38%) and COD (25–37%) were observed for all samples, suggesting that the salinity of the ROC did not have a significant impact on the UVC/H2O2 treatment under the test conditions. The biodegradability of the treated ROC samples improved markedly (approximately 2-fold) after 60 min UVC/H2O2 treatment. This study indicates the potential of UVC/H2O2 treatment followed by biological processes for treating high-salinity concentrate, and the robustness of the process where the characteristics of the secondary effluent (influent to RO) and thus resultant ROC vary significantly.

Evaluation of appropriate technologies for grey water treatments and reuses

2009 ◽  
Vol 59 (2) ◽  
pp. 249-260 ◽  
Author(s):  
Fangyue Li ◽  
Knut Wichmann ◽  
Ralf Otterpohl
Keyword(s):  
Water Reuse ◽  
Quality Standards ◽  
Urban Water ◽  
Water Quality Standards ◽  
Grey Water ◽  
Water Characteristics ◽  
Grey Water Reuse ◽  
Water Treatments ◽  
Treatment Alternatives ◽  
Economical Feasibility

As water is becoming a rare resource, the onsite reuse and recycling of grey water is practiced in many countries as a sustainable solution to reduce the overall urban water demand. However, the lack of appropriate water quality standards or guidelines has hampered the appropriate grey water reuses. Based on literature review, a non-potable urban grey water treatment and reuse scheme is proposed and the treatment alternatives for grey water reuse are evaluated according to the grey water characteristics, the proposed standards and economical feasibility.

Study on Environmental Materials with Application of Ozone-Based Technologies in Removal of Characteristic Pollutants in Pulp and Paper Effluents

2013 ◽  
Vol 700 ◽  
pp. 35-40
Author(s):  
Li Rong Lei ◽  
You Ming Li
Keyword(s):  
Ethylenediaminetetraacetic Acid ◽  
Oxygen Demand ◽  
Development Trend ◽  
Research Process ◽  
Pulp And Paper ◽  
Biological Processes ◽  
High Concentration ◽  
Emission Standard ◽  
Environmental Materials ◽  
Organic Halogens

Due to the presence of recalcitrant organic compounds, the pulp and paper effluents after treatment by conventional biological processes still contain high concentration of chemical oxygen demand (COD) and colored substances and do not satisfy the national emission standard. The objectives of this work are to present the research process on environmental materials with application of ozone-based technologies in removal of characteristic pollutants in pulp and paper effluents and suggest the feasible development trend. In this work, basic mechanisms of degradation of organic pollutants by ozone-based technologies in the presence of environmental materials as catalyst are described. The removal efficiencies of characteristic pollutants commonly found in pulp and paper effluents, such as absorbable organic halogens (AOX), resin and fatty acids, phenolic compounds, lipophilic wood extractives and ethylenediaminetetraacetic acid (EDTA), are presented.

scholarly journals Assessment of the Current Pollution Status of Jabi Lake in the Federal Capital Territory, Abuja, Nigeria

2019 ◽  
Vol 51 (3) ◽  
pp. 324
Author(s):  
Cyril Kanayochukwu Ezeamaka ◽  
Sadiq Queen ◽  
Daful Mwanret ◽  
Ogbole Moses ◽  
Anjide Theresa Wado
Keyword(s):  
Oxygen Demand ◽  
Mean Value ◽  
Who Guidelines ◽  
High Concentration ◽  
Domestic Water ◽  
Secchi Disc ◽  
Flame Atomic Absorption ◽  
Pollution Status ◽  
The Mean ◽  
Proactive Measures

This paper was aimed at providing the pollution status of Jabi Lake, FCT Abuja. 13 parameters were tested from raw water collected four sampling points. The physicochemical parameters were measured using Hanna multiparametric meter, while transparency was measured using Secchi disc. Dissolved oxygen, Biological and Chemical oxygen demand were measured titrimetrically using standard method. The concentrations of the metals were determined in triplicates. Flame atomic absorption spectrometer was used in the analysis as well as descriptive statistics (mean, standard deviation) and standard error. The Nigerian Industrial Standard and WHO guidelines for domestic water were used to compare the results of the water from the lake. The study reveals that the mean turbidity ranged between 21.6 – 24.2cm and is above the recommended limits of both WHO and NIS. The range of pH was between 6.3 and 8.8. pH is within a neutral range. The study reveals that the mean value of TDS and electrical conductivity is below the recommended limit of both WHO and NIS guidelines. The study shows that there is high concentration of some heavy metals (Cd, Cu, Ni, Mn, Zn, and Fe) in Jabi Lake. Cd, Zn, Fe and Ni are above the permissible limits of the NIS and WHO guidelines, which is an indication of pollution. The study, therefore, recommends that proactive measures be taken on environmental laws in FCT and that environmental/health worker and non-governmental bodies be active in enlightenment campaigns that will alert members of the public to the harm being caused to this important ecosystem.

scholarly journals CHALLENGES IN TEXTILE WASTEWATER AND CURRENT PALLIATIVE METHODS: AN OVERVIEW

2017 ◽  
Vol 18 (2) ◽  
pp. 71-78
Author(s):  
Ibrahim Adebayo Bello
Keyword(s):  
Oxygen Demand ◽  
Textile Wastewater ◽  
Wastewater Management ◽  
Textile Dye ◽  
Biological Processes ◽  
Dye Wastewater ◽  
High Concentration ◽  
Efficient Treatment ◽  
The Past ◽  
Textile Industries

Effluents from dye and textile industries are highly contaminated and toxic to the environment. High concentration of non-biodegradable compounds contributes to increased biochemical oxygen demand (BOD) and chemical oxygen demand (COD) of the wastewater bodies.  Dyes found in wastewater from textile industries are carcinogenic, mutagenic or teratogenic. Biological processes involving certain bacteria, fungi, activated carbon and carbon nanotubes (CNTs) are promising methods for treating the waste water. These methods are either inefficient or ineffective.  These complexities necessitates search for new approaches that will offset all the shortcomings of the present solutions to the challenges faced with textile wastewater management. This article reviews the past and recent methods used in the treatment of the textile dye wastewater and the future opportunities for efficient treatment of textiles wastewaters.

A pilot study of a subsurface-flow constructed wetland treating membrane concentrate produced from reclaimed water

2015 ◽  
Vol 72 (2) ◽  
pp. 260-268 ◽  
Author(s):  
Rajat K. Chakraborti ◽  
James S. Bays ◽  
Thien Ng ◽  
Lou Balderrama ◽  
Terry Kirsch
Keyword(s):  
Pilot Study ◽  
Organic Carbon ◽  
Constructed Wetland ◽  
Water Reuse ◽  
Reclaimed Water ◽  
Subsurface Flow ◽  
Oxygen Demand ◽  
Water Volume ◽  
Mass Removal ◽  
Nitrate N

A pilot study was conducted for 7 months for the City of Oxnard, California, on the use of constructed wetlands to treat concentrate produced by microfiltration and reverse osmosis (RO) of reclaimed wastewater. The treatment performance of a transportable subsurface-flow wetland was investigated by monitoring various forms of nitrogen, orthophosphate, oxygen demand, organic carbon, and selenium. Significant mass removal of constituents was measured under two hydraulic residence times (HRTs) (2.5 and 5 days). Inflow and outflow concentrations of nitrate-N and ammonia-N were significantly different for both HRTs, whereas nitrite-N and total organic carbon (TOC) were significantly different during HRT2. Mass removal by the constructed wetland averaged 61% of nitrate-N, 32% of nitrite-N, 42% of ammonia-N, 43% of biochemical oxygen demand, 19% of orthophosphate as P, 18% of TOC and 61% of selenium. Mass removal exceeded concentration reductions through water volume loss through evapotranspiration. Calibrated first-order area-based removal rates were consistent with literature ranges, and were greater during HRT1 consistent with greater mass loads, higher hydraulic loading and shorter HRTs. The rate constants may provide a basis for sizing a full-scale wetland receiving a similar quality of water. The results indicated that engineered wetlands can be useful in the management of RO membrane concentrate for reclaimed water reuse.

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