Wastewater Treatment for Effluent Reuse: Lime-Induced Removal of Excreted Pathogens

1989 ◽  
Vol 21 (3) ◽  
pp. 79-84 ◽  
Author(s):  
M. P. Gambrill ◽  
D. D. Mara ◽  
J. I. Oragui ◽  
S. A. Silva

High quality effluents suitable for crop irrigation can be produced by lime and Clarifloc treatment of raw domestic wastewater: in laboratory jar-test experiments the average percentage removals were 99.999 for faecal coliforms, 99 – 99.9 for salmonellae, 99.9 – 100 for total parasites and 99 – 99.9 percent for rotavirus. The average removals of COD and suspended solids were 79 – 87 and 97 percent respectively. Clarifloc treatment was marginally better than that achieved by lime.

2015 ◽  
Vol 71 (10) ◽  
pp. 1536-1544 ◽  
Author(s):  
P. de Rozari ◽  
M. Greenway ◽  
A. El Hanandeh

Constructed wetland ecotechnologies (CWEs) are a promising solution to effectively treat domestic wastewater in developing countries at low cost. This paper reports the findings of the effectiveness of sand media amended with woody biochar and two plants species (Melaleuca quinquenervia and Cymbopogon citratus) in removing biological oxygen demand (BOD5), suspended solids and coliforms. The experimental design consisted of 21 vertical flow (VF) mesocosms. There were seven media treatments using sand amended with varying proportions of biochar. During the first 8 months, the mesocosms were loaded with secondary clarified wastewater (SCW) then septage. The influent had a 4-day hydraulic retention time. Samples were monitored for BOD5, total suspended solids (TSS), total volatile solids (TVS), total coliforms and faecal coliforms. In the first 8 months, there were no significant performance differences between media treatments in the outflow concentrations of BOD5, TSS and TVS. The significant differences occurred during the last 3 months; using septage with biochar additions performed better than pure sand. For coliforms, the significant differences occurred after 6 months. In conclusion, the addition of biochar was not effective for SCW. The VF mesocosms system proved to be more effective in removing BOD5, TSS, TVS and coliforms when septage was loaded into the media.


Processes ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 527
Author(s):  
Nurul Shuhada Mohd Makhtar ◽  
Juferi Idris ◽  
Mohibah Musa ◽  
Yoshito Andou ◽  
Ku Halim Ku Hamid ◽  
...  

Wastewater treatment is crucial to ensure a sustainable supply of clean water, especially for human use. Natural flocculants can overcome the disadvantages of chemical flocculants in wastewater treatment. This study proposes a new natural-based flocculant from the Tacca leontopetaloides plant for leachate treatment. The plant tuber was processed through gelatinization to produce Tacca leontopetaloides biopolymer flocculant (TBPF). The characterization of TBPF for flocculant properties was investigated, and the performance of TBPF on leachate treatment using a standard jar test procedure was examined at different pH values of leachate and TBPF dosages. The characteristics of TBPF in terms of amylose/amylopectin fraction, viscosity, and zeta potential were 26:74, 0.037–0.04 Pa·s, and −13.14 mV, respectively. The presence of –COOH and –OH structure in TBPF indicates the flocculant properties. TBPF reduced the turbidity, total suspended solids (TSS), and color from 218 NTU, 214 mg/L, 14201 PtCo to 45.8–54.5 NTU, 19.3–19.9 mg/L, and 852–994 PtCo, respectively, using 240 mg/L of TBPF at pH 3. These results show a high potential of the new plant-based TBPF for leachate treatment and water industry applications.


2011 ◽  
Vol 64 (12) ◽  
pp. 2376-2380 ◽  
Author(s):  
Suwasa Kantawanichkul ◽  
Wanida Duangjaisak

The experiments were conducted in four concrete laboratory scale free water surface constructed wetland units 1 m wide, 1.5 m long and 0.8 m deep. Paddy field soil was added to a depth of 0.4 m and rice seedlings (Oryza sativa L.) were transplanted into the units at a density of 25 plants/m2. Domestic wastewater collected from Chiang Mai University was applied into each unit via two different modes to evaluate suitable conditions for wastewater treatment and rice yield. In the first experiment, the wastewater was fed intermittently (7 h/day) with a hydraulic loading rate of 2, 4, 6 and 8 cm/day. The maximum removal efficiencies for chemical oxygen demand, biological oxygen demand, total kjedahl nitrogen and suspended solids were only 49.1, 58.7, 64.0 and 59.4%, respectively, due to the short hydraulic retention time for the biodegradation of organic substances. In the second experiment, the wastewater in each unit was inundated to a depth of 15 cm for 10, 15, 20 and 25 days in each unit and then drained and re-flooded. Removal efficiencies of chemical oxygen demand, biological oxygen demand, total kjedahl nitrogen and suspended solids were greater than in the first experiment especially at the 25 day retention time and except for suspended solids met the Thai national effluent standard. The study revealed that apart from wastewater treatment, wastewater can replace natural water to grow rice in the dry season or throughout the year. Moreover, nutrients in wastewater can be a substitute for chemical fertilizers. Rice grain production was 4,700 kg/ha and only 6% less than the production from the conventional paddy field.


2021 ◽  
Author(s):  
Philiphi de Rozari

Deterioration of water quality continues to be a major concern in West Timor. Establishment of wastewater treatment is crucial for eliminating this problem. Constructed wetland (CW) ecotechnologies are an alternative low-cost wastewater treatment to solve wastewater problems in West Timor. This research aimed to compare the effectiveness of Thypa latifolia in CWs for the removal of BOD5, suspended solids, NH4-N, and PO4-P. The experimental design consisted of 6 (20 L) vertical flow mesocosms, 3 mesocosms planted with Thypa latifolia and 3 mesocosms as a control. The mesocosms were irrigated with synthetic wastewater for 7 months. The inflow had a 2-day hydraulic retention time. The inflow and outflow samples were monitored for BOD5, suspended solids, NH4-N, and PO4-P. The trend showed that the CWs planted with Thypa latifolia reduced significantly the BOD, suspended solids, and NH4-N. However, the presence of plant did not significantly reduce PO4-P. This indicated that the CWs planted with Thypa latifolia had a better performance in comparison with pure sand media


1992 ◽  
Vol 25 (4-5) ◽  
pp. 23-33 ◽  
Author(s):  
E. Billmeier

The activated sludge tank and the final settling tank represent one operating unit in which the mixed liquor suspended solids indicate the main parameter. This parameter depends on the efficiency of the final settling tank so that this building determines the capacity of the whole wastewater treatment plant. The effluent quality improves with the separation capability of the clarifier because the suspended solids contain relatively large concentrations of BOD5 and COD and significant values of organic nitrogen and total phosphorus.


2020 ◽  
Vol 82 (9) ◽  
pp. 1877-1884
Author(s):  
Güler Türkoğlu Demirkol ◽  
Gökhan Balcıoğlu ◽  
Nurtaç Öz ◽  
Moiz Elnekave ◽  
Bülent Armağan ◽  
...  

Abstract Domestic wastewaters causing pollution contain inorganic and/or organic materials. When the domestic wastewater outflows to the receiving waters, it causes physical, chemical, and biological pollution in them, and deteriorates the ecological balance of those waters. In the treatment of wastewater, various treatment methods are available depending on the pollution strength of the wastewater. Besides mechanical and biological methods, wastewater treatment with physicochemical methods is still one of the most effective and economical options. Particularly in wastewater with a high concentration of suspended solids, this method is very successful, and obtaining high suspended solids removal efficiencies is very possible. In this study, the effects of the use of coagulant and coagulant aid to be used in a treatment plant where domestic wastewater treatment is carried out are determined to increase the treatment efficiency of a biological treatment that comes later in the stages of the treatment. The effluent of the pre-settling tank may contain a lot of suspended solids. This presence of excess suspended solids decreases the efficiency at other levels of treatment and causes energy loss. In the experiments, the standard jar and inhibition tests are done as a method. As a result of the conducted studies, it is determined that the FeCl3, Synthetic coagulant LP 526, FeClSO4, and the combination of anionic polyelectrolyte yield the best results in the removal of the parameters of chemical oxygen demand (COD), total suspended solids (TSS), and volatile suspended solids (VSS). While FeCl3, APE 65, APE 85, Synthetic coagulant LP 526, and FeClSO4 did not show any inhibition effect in the sludge, APE 67, CPE 84, and (Al2(SO4)3 are found to cause inhibition in the sludge.


2021 ◽  
Vol 26 (3) ◽  
pp. 3-15
Author(s):  
G. T. Ambrosova ◽  
◽  
A. V. Kruglikova ◽  
A. P. Kolodeznikova ◽  
A. P. Semenova ◽  
...  

Introduction. In this paper, we consider the operation principle, features, advantages, and disadvantages of compact domestic wastewater treatment plants designed by domestic manufacturers. The compact plants used until 2000 were designed to reduce such two indicators in the waste liquid as BOD and suspended solids. Since 2000, modern compact plants capable of reducing four indicators (BOD, suspended solids, nitrogen, and phosphorus) have been developed and installed in Russia. Methods. Biological methods of removing organic substances and nitrogen from the waste liquid are used at modern compact plants. Phosphorus is removed by using both biological and physical-and-chemical methods. The main issue in the operation of compact domestic wastewater treatment plants is the extremely nonuniform flow of wastewater; the coefficient of hourly nonuniformity can be 3.5 or higher. Another serious issue is the reduction in the waste liquid temperature in the cold period to critical values that hinder the biochemical oxidation of organic substances in aeration tanks. In permafrost areas (Yakutia), the influence of this factor can be observed even in the warm period. Results. Based on theoretical research and many years of experience in commissioning, we identified the consequences of design flaws and violations during operation for the stability and performance efficiency of compact plants of various modifications. Conclusion. The performed study made it possible to develop and recommend the optimal option for wastewater treatment, which allowed us to ensure that the indicators were brought to the maximum permissible concentrations of pollutants (suspended solids — 2–3 mg/l, BODult — 3–5 mg/l, ammonium nitrogen — 0.4 mg/l, nitrate nitrogen — 9 mg/l, phosphorus — 0.2 mg/l), established for discharge into fishing reservoirs.


2012 ◽  
Vol 7 (3) ◽  
Author(s):  
George Skouteris ◽  
Tom C. Arnot ◽  
Firas Feki ◽  
Mouna Jraou ◽  
Sami Sayadi

A pilot-scale aerobic membrane bioreactor (MBR) was operated for 6.5 months, alongside a full-sized conventional activated sludge (AS) plant, treating high-strength domestic wastewater originating from Sfax in Tunisia. The main target was to investigate whether or not the MBR could produce effluent suitable for unrestricted crop irrigation in Tunisia, a target that the AS plant fails to achieve. Membrane performance analysis and energy benchmarking were also carried out. The MBR did produce irrigation quality water regardless of the mixed-liquor suspended solids (MLSS) or feed concentrations. The average chemical oxygen demand (COD) removal efficiency was 88% at an average MLSS concentration of 4.59 g L−1, and 89.7% at an average MLSS concentration of 9.52 g L−1. During membrane performance evaluation, a maximum sustainable membrane permeate flux of 12.81 L m−2 h−1, at an average mixed-liquor temperature of 24 °C and an average MLSS concentration of 9.21 g L−1 was maintained. Finally, energy benchmarking was carried out; the average energy consumption rate was 8.95 kWh d−1, corresponding to an average specific energy demand (SED) of 3.82 kWh m−3. This is a relatively high value compared to the AS plant, whose SED value is always lower than 3 kWh m−3, but further energy reduction is possible for the MBR as well as the AS plant effluent requires further treatment in order to be acceptable for unrestricted human crop irrigation; hence, additional energy input. The work demonstrates the potential impact of MBRs in decentralised domestic wastewater treatment in North Africa.


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