Hybrid treatment systems - anaerobic ponds and trickling filters in Zimbabwe

2003 ◽  
Vol 48 (2) ◽  
pp. 349-356 ◽  
Author(s):  
J.M. Broome ◽  
P.M. Morris ◽  
J.G. Nanthambwe
Keyword(s):  
Sewage Treatment ◽  
Site Conditions ◽  
Two Stage ◽  
Eucalyptus Plantation ◽  
Trickling Filters ◽  
Hybrid Treatment ◽  
Treatment Processes ◽  
Treated Effluent ◽  
Settling Ponds ◽  
Removal System

The most economic combination of unit treatment processes for a new sewage treatment works in Zimbabwe was found to be anaerobic ponds followed by trickling filters. The regulations governing irrigation with treated effluent permitted the omission of humus tanks or further treatment. Two stage anaerobic ponds are desludged by gravity through fixed sludge outlet pipework. Sludge is disposed of by irrigation of a Eucalyptus plantation. Novel features of the inlet works and pond outlets are also described. The works has functioned for eight years without major problems, but the assumption that humus tanks or settling ponds were not required may have been mistaken. The sludge removal system has worked well. Without the sludge pipework, it is estimated that desludging of the primary ponds would have been required after two years of operation, but they have now operated successfully for eight years. The combination of anaerobic ponds and trickling filters should be considered where land availability or site conditions make facultative ponds difficult or expensive to construct.

Nutrient reduction evaluation of sewage effluent treatment options for small communities

2005 ◽  
Vol 51 (10) ◽  
pp. 221-229 ◽  
Author(s):  
P.D. Beavers ◽  
I.K. Tully
Keyword(s):  
Total Nitrogen ◽  
Sewage Treatment ◽  
Subsurface Flow ◽  
Primary Objective ◽  
Effluent Treatment ◽  
Sand Filter ◽  
Small Communities ◽  
Treatment Processes ◽  
Treated Effluent ◽  
Slow Sand Filter

Small communities that are sewered by either package sewage treatment plants or on-site sewerage facilities are finding that the ground and surface waters are being contaminated. Nitrogen, which typically is not removed in these conventional systems, is a major concern. This project evaluated the capability of four sewage treatment technologies to reduce the amount of nitrogen being discharged in the effluent to the receiving environment. The four sewage treatment processes evaluated include a recirculating sand filter, biofilter, slow sand filter and constructed subsurface flow wetland. These processes were evaluated for their capability to reduce nitrogen, phosphorus, BOD5 and TSS. The primary objective of the project was to evaluate the capability of these treatment processes to reduce nitrogen using biological processes nitrification and denitrification. This paper reports on the performance of these processes to reduce nitrogen. The study demonstrated that the biofilter was capable of removing from a primary treated influent 40% of the total nitrogen. For the same quality influent the recirculating sand filter was capable of removing 35% of the total nitrogen. Secondary treated effluent was fed to the slow sand filter and the subsurface flow wetland. There was a 52% reduction in total nitrogen through the wetland however there was virtually no reduction in total nitrogen through the slow sand filter.

High rate and compact two-stage post-denitrification process with single-sludge pre-denitrification

1996 ◽  
Vol 34 (1-2) ◽  
pp. 467-475
Author(s):  
Kazuhiro Mikawa ◽  
Hiroyoshi Emori ◽  
Tadashi Takeshima ◽  
Eiichi Ishiyama ◽  
Kazuhiro Tanaka
Keyword(s):  
Total Nitrogen ◽  
Phosphorus Removal ◽  
Sewage Treatment ◽  
High Rate ◽  
Nitrogen And Phosphorus ◽  
Nitrogen And Phosphorus Removal ◽  
Two Stage ◽  
Treatment Processes ◽  
Closed Water ◽  
Denitrification Process

For the sewage treatment plants near rivers and closed water bodies in urbanized areas there is a growing demand for introduction of advanced treatment processes for nitrogen and phosphorus removal for water quality conservation and environmental protection. In order to achieve the total nitrogen content of below 10 mg/L in effluent, a compact single sludge pre-denitrification process by dosing immobilized pellets in the nitrification tank (PEGASUS process) has been already developed (Tanaka et al. 1992). Furthermore, a two-stage PEGASUS process and a PEGASUS process with post-denitrification were developed and investigated for nitrogen removal. Both processes achieved the total nitrogen of less than 5mg/L.

Evaluation of estrogen-like activity on sewage treatment processes using recombinant yeast

2002 ◽  
Vol 46 (11-12) ◽  
pp. 367-373 ◽  
Author(s):  
K. Onda ◽  
S.-Y. Yang ◽  
A. Miya ◽  
T. Tanaka
Keyword(s):  
Activated Sludge ◽  
Advanced Oxidation Process ◽  
Sewage Treatment ◽  
Pilot Scale ◽  
Recombinant Yeast ◽  
Treatment Processes ◽  
Treated Effluent ◽  
Yeast Assay ◽  
Treated Effluents

Four sewage treatment plants based on an activated sludge process and a pilot scale plant for advanced sewage treatment located in Japan were evaluated for removal of estrogenic substances using in vitro recombinant yeast assay and chemical analysis. The results indicated that 17βl-estradiol (E2) significantly contributed to estrogen-like activity analyzed by yeast assay especially in secondary treated effluents. On the other hand, batch study showed that estrogen-like activity of spiked E2 was easily decreased by an activated sludge treatment. This result suggested that E2 concentrations measured by enzyme immunoassay (EIA) were interpreted as false positives in effluents, and that unknown estrogenic substances other than E2 might have contributed to estrogen-like activity in the secondary treated effluents. Further, in the pilot scale study, advanced sewage treatment processes such as a biological aerated filtration (BAF) process, an advanced oxidation process (AOP), were effective for the removal of those estrogenic activities contributed by unknown estrogenic substances in sewage secondary treated effluent.

Sewage Treatment in Helophyte Beds–First Experiences with a New Treatment Procedure

1987 ◽  
Vol 19 (10) ◽  
pp. 1-10 ◽  
Author(s):  
K. Bucksteeg
Keyword(s):  
Waste Water ◽  
Rural Areas ◽  
Root Zone ◽  
Waste Water Treatment ◽  
Sewage Treatment ◽  
Uptake Capacity ◽  
Humid Climate ◽  
Climate Conditions ◽  
Trickling Filters ◽  
Operation Conditions

Waste water treatment in helophyte beds under humid climate conditions has been favoured by some German ecologists for some years. The idea is to cause waste water to flow horizontally through the root zone of helophytes to achieve satisfactory effluent properties. There exist many highly different proposals regarding the choice of soil and helophytes to be applied, bed area, design of inlets and outlets and operation conditions. A few plants have been operated in practice for some years. It appears that clogging is one of the main problems occurring in these plants. The hydraulic uptake capacity of soil is discussed in Darcy's law. Comparisons with observations of plants in operation are drawn. The interactions between soil properties, its uptake capacity, BOD5-, COD-, N- and P-reduction are evaluated. The effluent results of helophyte beds are compared with those of low-loaded trickling filters and of ponds used for sewage treatment in small villages in rural areas of Germany. It has been proved that the total construction costs of sewage treatment plants with helophyte beds used as the biological stage are higher when compared with those of conventional plants in general.

Water Quality Aspects of the Nakdong Estuary Barrage

1984 ◽  
Vol 16 (1-2) ◽  
pp. 243-252 ◽  
Author(s):  
J W van Sluis ◽  
L Lijklema
Keyword(s):  
Water Quality ◽  
Water Quality Management ◽  
Sewage Treatment ◽  
Large River ◽  
Model Verification ◽  
Nakdong River ◽  
Treated Effluent ◽  
Quality Aspects ◽  
The Nakdong River ◽  
Few Data

As a result of the construction of a barrage in the estuary of the Nakdong river the size of the estuary will be considerably reduced. In addition, a large river reservoir is created upstream of the barrage. Main points of interest are the effects of the discharge of raw sewage and treated effluent into the Nakdong river on the water quality in the projected reservoir and the water quality forecasts for the remaining part of the estuary, in relation with the existing plans for sewerage and sewage treatment for the city of Busan. In addition, measures to reduce the effects of the barrage and the outline of a water quality management programme are presented. Special consideration is given to the methodological aspects of the water quality study, i.e. the selection and use of mathematical models in a situation where input data are rather uncertain and only very few data for parameter estimation and model verification are available.

Evaluation of the alternative treatment processes to upgrade an Opium alkaloid wastewater treatment plant

2000 ◽  
Vol 41 (1) ◽  
pp. 223-230 ◽  
Author(s):  
M.F. Sevimli ◽  
A.F. Aydin ◽  
Ì. Öztürk ◽  
H.Z. Sarikaya
Keyword(s):  
Activated Sludge ◽  
Alternative Treatment ◽  
Treatment Plant ◽  
Post Treatment ◽  
Anaerobic Sludge ◽  
Processing Plant ◽  
Two Stage ◽  
Sludge Treatment ◽  
Treatment Processes ◽  
Opium Alkaloid

The aim of this study is to characterize the wastewater from an opium alkaloid processing plant and to evaluate alternative treatment techniques to upgrade an existing full-scale biological activated sludge treatment plant having problems of high residual COD and unacceptable dark brown color. In this content firstly, long term operational records of the two stage aerobic activated sludge treatment plant of the opium alkaloid factory located in Afyon province of Turkiye were evaluated. The operating results for the last three years were statistically analyzed and median and 95-percentile values were determined for the parameters including chemical and biological oxygen demand (COD and BOD5) and treatment efficiencies. Specific wastewater generation was found as 6.7 m3 per ton of the opium capsule processed. In the following stage of the study, three additional treatment processes were experimentally tested: anaerobic pretreatment, post treatment of aerobically treated effluents with lime and ozone. Pilot scale upflow anaerobic sludge blanket reactor (UASBR) experiments have demonstrated that about 70 percent of the incoming COD can be removed anaerobically. Chemical treatability studies with lime for the aerobically treated effluent have shown that about 78 percent color and 46 percent COD removals can be obtained with lime dosage of 25 gl−1. Post treatment of the effluents of the existing two stage aerobic treatment with ozone also resulted in significant color and COD reduction.

Treated Effluent in Concrete Technology

2012 ◽  
Author(s):  
Soon Lee Ooi ◽  
Mohd Razman Salim ◽  
Mohammad Ismail ◽  
Md. Imtiaj Ali
Keyword(s):  
Compressive Strength ◽  
Potable Water ◽  
Setting Time ◽  
Sewage Treatment ◽  
Concrete Technology ◽  
Water Quality Control ◽  
Treated Effluent ◽  
Compressive Strength Test ◽  
Direct Discharge ◽  
Mixing Water

In this paper, the feasibility of using treated effluent for concrete mixing was studied. Treated effluent from sewage treatment plants in Malaysia is currently being wasted through direct discharge into waterways. With proper water quality control, this treated effluent can also be considered as a potential water resource for specific applications. Two tests were carried out namely compressive strength test and setting time to determine the feasibility of using treated effluent for concrete mixing. The results were compared against the test conducted on control specimens which used potable water. The results showed that treated effluent increases the compressive strength and setting time when compared with potable water. Key words: treated effluent; mixing water; compressive strength; setting time; concrete technology.

scholarly journals Abundance and distribution of microplastics in water and sediment of Baiyangdian Lake, Northern China

2021 ◽  
Author(s):  
Yanyan Fang
Keyword(s):  
Surface Water ◽  
Sewage Treatment ◽  
Pollution Abatement ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Northern China ◽  
Baiyangdian Lake ◽  
Treated Effluent ◽  
Transfer Station ◽  
Main Components

Abstract Microplastics (MPs) have been found in all environment matrices and have become an issue of concern worldwide. In this study, Baiyangdian Lake in Northern China was investigated for the presence of MPs (0.45 µm–5 mm) in sediment and at different water depths. MPs were found at 1,000–20,000 pieces/m3 (average 9,595) in water and at 400–2,200 pieces/kg (average 1,023) in sediment. Since the implementation of pollution abatement measures, visible MPs have been nearly eliminated; the MPs found in this study were mainly in the micrometer range, with no more than 3–5 pieces greater than 1 mm per sample. The main forms of MPs were fibrous and fragmented, and the main components were polyamide, polyethylene, and polypropylene. MPs found in water near a garbage transfer station showed the following abundance of MPs: surface water < middle water < bottom water. The sediment contained a higher amount of MP fragments, indicating that the historical transfer and disposal of garbage was a main source of plastic deposition in this area. There was a high content of fibrous MPs in surface water, while the abundance of fragmented MPs increased with the depth of water. The main sources of MPs in the study area were residential activities, local plastic factories, and the treated effluent from a sewage treatment plant.

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