scholarly journals A COMPARATIVE STUDY ON TREATMENT TECHNOLOGIES FOR SEWAGE RECLAMATION: A FOCUS ON THE DISINFECTION PROCESS

2020 ◽  
Vol 21 (2) ◽  
pp. 80-99
Author(s):  
Noorini Izzati Mohamad Mazuki ◽  
Yeit Haan Teow ◽  
Abdul Wahab Mohammad

Selection of suitable disinfection technology is necessary with regards to wastewater reclamation goals. In this work, the performance of various disinfection technologies - single disinfection units and integrated disinfection systems - on local sewage was studied for non-potable reuse. Disinfection units used as stand-alone units include ultraviolet (UV) disinfection, chlorination, microfiltration (MF), and ultrafiltration (UF). The integrated disinfection system consists of UV or chlorination as the primary disinfection unit incorporated with either MF, UF, multi-media or granular activated carbon as pre-treatment. The performance of these disinfection units and integrated processes were evaluated based on the percentage of removal of biochemical oxygen demand, chemical oxygen demand, total suspended solids, ammonia nitrogen, nitrate nitrogen, phosphorus, Escherichia coli, and trihalomethane in bench-scale disinfection systems. The single unit of PES20kDa membrane and the integrated disinfection system of UF-Cl showed the most effective treatment among single disinfection units and integrated systems, respectively. The results showed that almost all disinfection units and integrated disinfection processes were useable for restricted and unrestricted area non-potable applications according to United State Environmental Protection Agency (US EPA) water reuse guidelines and managed to fulfil Singapore grey water quality for recycling. ABSTRAK: Pemilihan teknologi penyahjangkitan kuman yang sesuai adalah perlu selaras dengan matlamat pemulihgunaan air buangan. Kajian ini adalah tentang prestasi pelbagai teknologi penyahjangkitan kuman - unit tunggal penyahjangkitan kuman dan sistem penyahjangkitan kuman bersepadu pada air sisa kumbahan tempatan dikaji bagi penggunaan semula air minuman. Unit  tunggal penyahjangkitan kuman yang digunakan mempunyai penyahjangkitan kuman ultraungu (UV), pengklorinan, mikro penurasan (MF), dan ultra penurasan (UF). Manakala, sistem penyahjangkitan kuman bersepadu terdiri daripada UV atau pengklorinan sebagai unit penyahjangkitan kuman utama yang digabungkan bersama samada dengan MF, UF, multi-media atau karbon teraktif berbutir sebagai proses pra-rawatan. Prestasi unit tunggal penyahjangkitan kuman dan proses-proses bersepadu dinilai berdasarkan pada peratus penyingkiran keperluan oksigen biokimia, permintaan oksigen kimia, jumlah pepejal terampai, nitrogen ammonia, nitrogen nitrat, fosforus, coli Escherichia, dan trihalometana dalam sistem penyahjangkitan kuman berskala-makmal. Unit tunggal penurasan ultra membran PES20kDa dan sistem penyahjangkitan kuman bersepadu UF-Cl menunjukkan masing-masing paling efektif dalam rawatan unit tunggal dan sistem penyahjangkitan kuman bersepadu. Keputusan menunjukkan bahawa hampir semua unit tunggal penyahjangkitan kuman dan proses penyahjangkitan kuman bersepadu boleh diguna pakai bagi aplikasi terhad dan tidak terhad  mengikut garis panduan penggunaan semula air sisa rawatan yang ditetapkan oleh Agensi Pelindungan Alam Sekitar Amerika Syarikat (US EPA) dan kualiti kitar semula air sisa Singapura.

2013 ◽  
Vol 67 (9) ◽  
Author(s):  
Karina Michalska ◽  
Stanisław Ledakowicz

AbstractThis work studies the influence of the alkali pre-treatment of Sorghum Moench — a representative of energy crops used in biogas production. Solutions containing various concentrations of sodium hydroxide were used to achieve the highest degradation of lignocellulosic structures. The results obtained after chemical pre-treatment indicate that the use of NaOH leads to the removal of almost all lignin (over 99 % in the case of 5 mass % NaOH) from the biomass, which is a prerequisite for efficient anaerobic digestion. Several parameters, such as chemical oxygen demand, total organic carbon, total phenolic content, volatile fatty acids, and general nitrogen were determined in the hydrolysates thus obtained in order to define the most favourable conditions. The best results were obtained for the Sorghum treated with 5 mass % NaOH at 121°C for 30 min The hydrolysate thus achieved consisted of high total phenolic compounds concentration (ca. 4.7 g L−1) and chemical oxygen demand value (ca. 45 g L−1). Although single alkali hydrolysis causes total degradation of glucose, a combined chemical and enzymatic pre-treatment of Sorghum leads to the release of large amounts of this monosaccharide into the supernatant. This indicates that alkali pre-treatment does not lead to complete cellulose destruction. The high degradation of lignin structure in the first step of the pre-treatment rendered the remainder of the biomass available for enzymatic action. A comparison of the efficiency of biogas production from untreated Sorghum and Sorghum treated with the use of NaOH and enzymes shows that chemical hydrolysis improves the anaerobic digestion effectiveness and the combined pre-treatment could have great potential for methane generation.


Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 854 ◽  
Author(s):  
Samuel D. Jesse ◽  
Paul C. Davidson

Recycling post-hydrothermal liquefaction wastewater (PHWW) may allow the use of nutrients in the aqueous phase that may otherwise go unused. PHWW is an attractive option for use as fertilizer in systems like crop production. However, there are potential contaminants in the PHWW that may inhibit crop growth or pose a food safety risk. This study investigated the concentrations of heavy metals and nutrients in the PHWW, as well as the presence of indicator pathogens. In addition, four different water treatment methods were used: (1) dilution of raw PHWW, (2) sand filtration after dilution, (3) sand and carbon filtration after dilution, and (4) reverse osmosis after dilution. Our results indicate that the concentrations of cadmium, lead, and arsenic in raw PHWW were well below the maximum recommended concentrations set by the US Environmental Protection Agency (US EPA) for Water Reuse. In addition, the treatment methods in this study achieved percent removals ranging from 82–100% for cadmium, 99–100% for mercury, 75–99.5% for lead, and 71–99% for arsenic. Nitrogen in raw PHWW was predominantly in the total N form, preventing it from being accessible to plants. After nitrification was induced, the concentration of NO3 + NO2 increased by 1.75 mg/L in the untreated 5% PHWW mixture, but remained unchanged or decreased for all other treatments and mixtures. There were no E. coli or coliform colonies detected in the raw PHWW, or in any PHWW mixtures. All PHWW mixtures with and without treatment are within US EPA guidelines for metals for irrigation water reuse. However, fertilizer supplementation may be required for PHWW to be suitable for crop production, as the low concentrations of NO3 + NO2 may prove challenging for growing crops.


1982 ◽  
Vol 14 (9-11) ◽  
pp. 1393-1429 ◽  
Author(s):  
R D Heaton

Water recycling systems implies the initial treatment requirements for various water reuse schemes including unit process descriptions, performance and cost data. Several volumes of text are required for adequate coverage of the above subject and this paper will only attempt to highlight important areas, provide guidelines and give needed direction. Cost functions of one important U.S. Research/ Demonstration Facility (Water Factory 21) are given in more detail. Much of the data has been summarized from four important publications shown below and the reader seeking additional information is encouraged to examine these in detail.1.Water Reuse and Recycling - Volume 2 - Evaluation of Treactment Technology, 1979, U.S. Office of Water Research & Technology (OWRT). Report by Culp/Wesner/Culp Engineers, NTIS #PB 80-131469.2.Guidelines for Water Reuse, August 1980, U.S. Environmental Protection Agency. Report by Camp Dresser & McKee Engineers, NTIS #PB 81-105017.3.Evaluation of, Membrane. Processes and Their Role in Wastewater Reclamation, 1981. OWRT sponsored report by Orange County Water District, Fountain Valley, California, USA.4.Municipal Wastewater Reuse News. OWRT sponsored monthly newsletter by AWWA Research Foundation, Denver, Colorado, USA.


2000 ◽  
Vol 42 (1-2) ◽  
pp. 263-268 ◽  
Author(s):  
R. Messalem ◽  
A. Brenner ◽  
S. Shandalov ◽  
Y. Leroux ◽  
P. Uzlaner ◽  
...  

In Israel the shortage of water and concern for the quality of groundwater resources have led to an awareness that a national wastewater reclamation program must be developed. Such a program could cover a major part of the agricultural water demand and could facilitate disposal of effluents without health hazards or environmental problems. A two-stage pilot-scale system comprising secondary sequencing batch reactor (SBR) treatment and tertiary microfiltration was operated for the treatment of Beer-Sheva municipal wastewater. The self-cleaning, continuous microfiltration system comprised a filter module made up of hollow fiber microporous membranes, with a pore size distribution of less than 0.1 μm, encapsulated into a bundle. The unit, which has a nominal filtration area of 4 m2, can treat 4–5 m3 of sewage per day, at a nominal rate of about 500 L/h. SBR treatment of the raw sewage produced an effluent with a biochemical oxygen demand (BOD) of <20 mg/L and total suspended solids (TSS) of <20 mg/L. Further treatment by microfiltration resulted in a BOD <5 mg/L, TSS <1 mg/L and turbidity <0.2 nephelometric turbidity units (NTU). Bacterial counts showed 6-log removal of coliforms and fecal coliforms. These results indicate that the two-stage scheme is capable of producing an effluent that meets or even surpasses the requirements for unrestricted water reuse for agriculture.


2017 ◽  
Vol 76 (9) ◽  
pp. 2544-2553 ◽  
Author(s):  
Beata Karolinczak ◽  
Wojciech Dąbrowski

Abstract Septage is wastewater stored temporarily in cesspools. A periodic supply of its significant quantities to small municipal wastewater treatment plants (WWTPs) may cause many operational problems. In the frame of the research, it has been proposed to utilize vertical flow constructed wetlands for pre-treatment of septage prior to its input to the biological stage of a WWTP. The aim of the work was to assess the effectiveness of pre-treatment in relation to factors such as: seasonality, hydraulic load, pollutants load of the VF bed and interactions between these factors. The results proved that application of a VF bed to septage pre-treatment can significantly reduce the concentration of pollutants (biochemical oxygen demand (BOD5): 82%, chemical oxygen demand (COD): 82%, total suspended solids (TSS): 91%, total nitrogen (TN): 47%, ammonia nitrogen (NH4-N): 70%), and thus decrease the loading of the biological stage of a WWTP. The mathematical models of mass removal process were created. They indicate that in case of all analysed parameters, removed load goes up with the increase of load in the influent. However, with the increase of hydraulic load, a decrease of the removed BOD5, COD, TSS and total phosphorus, and in vegetation period an increase of TN, can be observed in terms of load. There are no statistically significant effects of seasonality.


2019 ◽  
Vol 33 (3) ◽  
pp. 417-425 ◽  
Author(s):  
Davor Dolar ◽  
Marko Racar ◽  
Krešimir Košutić

Municipal wastewater was treated by membrane bioreactor (MBR), and the obtained<br /> MBR effluent was then treated by reverse osmosis (RO), and nanofiltration (NF). The MBR effluent was additionally treated by reverse osmosis (XLE) and nanofiltration (NF90 and NF270) membranes. RO and NF permeate output streams were assessed for their utilization in agricultural irrigation. The MBR used a hollow fiber ZeeWeed 1 ultrafiltration<br /> membrane. Conductivity, turbidity, total suspended solids, chemical oxygen demand, and dissolved organic carbon were rejected by MBR with average values of 10 %, 100 %, 99.8 %, 96 %, and 88 %, respectively. Further treatment with RO/NF membranes showed additional reduction in all measured parameters. According to results, MBR effluent belongs to the ‘slight to moderate’ degree of restriction on use due to conductivity, chloride, and sodium concentrations. RO/NF permeate, based on all parameters, belongs<br /> to the ‘none’ degree of restriction on use, except on sodium adsorption ratio (SAR), where it belongs to the ‘severe’ degree of restriction on use. Based on conductivity and SAR parameters, assessment of produced water quality obtained by blending of two effluents<br /> (50 % of MBR and 50 % of NF270 permeate) resulted in an output stream appropriate for irrigation, proving that the blending of output streams in this ratio is a good strategy for agricultural irrigation.


2011 ◽  
Vol 64 (11) ◽  
pp. 2177-2184 ◽  
Author(s):  
J. Zhai ◽  
H. W. Xiao ◽  
K. Kujawa-Roeleveld ◽  
Q. He ◽  
S. M. Kerstens

A new type of hybrid constructed wetland (CW), consisting of both vertical-baffled flow wetland (VBFW) and horizontal subsurface flow wetland (HSFW), has been deployed in Southern China to naturally accelerate the removal of organic matter and nitrogen. The hybrid CW system is characterised by a combination of continuous baffled flow vertical wetland and ‘S’ pattern horizontal subsurface flow wetland with natural aeration ditches to increase the concentration of dissolved oxygen in the HSFW bed. An internal circulatory system from the HSFW effluent back to the VBFW may optionally be operated to enhance the biological denitrification effect. Cyperus alternifolius is the main macrophyte in the wetland bed. The performance of the hybrid CW was studied with a pilot-scale system and three full-scale systems for municipal sewage treatment in Southern China. The results suggest that this new hybrid CW can achieve removal efficiencies of chemical oxygen demand, suspended solids, ammonia nitrogen, total nitrogen, and total phosphorus of better than 83.6, 95.0, 71.7, 64.5 and 68.1% respectively, with a specific wetland bed area of 0.70–0.93 m2 PE−1. The mean effluent concentrations of these parameters would meet the regulatory discharge limits for wastewater treatment systems (GB18918, 2002) and reuse in the context of agricultural irrigation solutions in China.


2008 ◽  
Vol 58 (4) ◽  
pp. 919-923 ◽  
Author(s):  
X. J. Wang ◽  
S. L. Chen ◽  
X. Y. Gu ◽  
K. Y. Wang ◽  
Y. Z. Qian

The combination of chemical and biological treatment processes is a promising technique to reduce refractory organics from wastewater. Ozonation can achieve high color removal, enhance biodegradability, and reduce the chemical oxygen demand (COD). The biological technique can further decrease COD of wastewater after ozonation as a pre-treatment. In this study the ozonizing-biological aerated filter processes were used to treat textile washing wastewater for reuse after conventional treatment. The result showed that when the influent qualities were COD about 80 mg/L, color 16 degree and turbidity about 8 NTU, using the combination processes with the dosages of ozone at 30–45 mg/L with the hydraulic retention time (HRT) of biological aerated filter (BAF) at 3–4 hours respectively, gave effluent qualities of COD less than 30 mg/L, color 2 degree and turbidity less than 1NTU. The cost of treatment was less than one yuan/t wastewater, and these processes could enable high quality washing water reuse in textile industry.


Author(s):  
Hanna Kyllönen ◽  
Juha Heikkinen ◽  
Javier Ceras ◽  
Claudio Fernandez ◽  
Olaf Porc ◽  
...  

Abstract Intense pressure on water resources has led to efforts to reuse reclaimed processing wastewater in the food industry. There are tight rules for water quality, but efficient separation technologies such as reverse osmosis possess good possibilities for water reuse. This study developed a membrane-based reuse water concept for wastewater from the candy industry emphasizing the pre-treatment stage in the concept to reduce fouling. The wastewater contained suspended solids, sugar compounds and the ingredients for candy gelation, which had a tendency to foul membranes, making pre-treatment essential for successful concept. Cross-rotational ultrafiltration, which featured enhanced fouling prevention for membranes, functioned well for the removal of challenging substances. Conventional filtration technologies were impractical due to a low flux, even when the viscosity of the wastewater was reduced using surfactants. The wastewater had a high chemical oxygen demand, meaning that there were a strong fouling potential for reverse osmosis membranes, but also high osmotic pressure. A spiral wound reverse osmosis functioned well when the wastewater was pre-treated, and it produced good quality water with respect to all the other studied parameters except the chemical oxygen demand. However, chemical oxygen demand rejection was 99% since the concentration in the wastewater was originally very high.


2011 ◽  
Vol 347-353 ◽  
pp. 2078-2084
Author(s):  
Chen Yan Hu

The main objectives of this study were to describe the municipal solid waste management, leachate characteristics of China landfills, and to summarize the present research of leachate treatments in china such as biological treatment, physical and chemical treatment and land treatment. In the survey of leachate from landfill in Chinese megapolis, the quality is characterized by chemical oxygen demand (COD) of 1500-80000 mg/L, biochemical oxygen demand (BOD) of 200-35000 mg/L, ammonia nitrogen (NH3-N) of 50-2400 mg/L, total nitrogen of 80-2600 mg/L, suspended solid of 30-7000 mg/L and pH value of 5-7.8. In engineering practices of China, the biological systems are usually adopted. Meanwhile, as far as the special quality of leachate is concerned, some chemical treatments are used as the pre-treatment or post-treatment to promote the effluent or improve the biological degradability of leachate.


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