Control of disinfection byproduct (DBP) precursors by soil aquifer treatment (SAT): what length of hydraulic retention time (HRT) is necessary?

2016 ◽  
Vol 16 (6) ◽  
pp. 1648-1658 ◽  
Author(s):  
Songkeart Phattarapattamawong ◽  
Yugo Takabe ◽  
Shinya Echigo ◽  
Sadahiko Itoh

The study attempted to determine the hydraulic retention time (HRT) required for soil aquifer treatment (SAT) to reclaim water as potable water in an aspect of controlling disinfection byproduct (DBP) precursors. In order to evaluate the removal of DBP precursors, the uniform formation condition was used to estimate the formations of trihalomethanes (THMs) and haloacetic acids (HAAs). Effluent water from anaerobic-anoxic-oxic processes (A2O water) was fed through soil columns at different HRTs. Sand with low organic content and less specific surface area was selected to represent the ‘worst available case’ of subsurface environment in Japan. Overall, annual data (n ≥ 14) indicated that the average concentrations of THMs and HAAs for water passed through SAT with HRT less than 7 days were below the standard of drinking water. However, risks of exposure to THMs and HAAs were observed. Increasing HRT to 30 days resulted in the concentrations of regulated THM and HAA species lower than the 10% of the drinking water standard values, except for dichlorobromoform. Therefore, a treatment unit for bromide ion removal (e.g., anion exchanger) prior to chlorination is recommended to lower the risk levels of exposure to dichlorobromoform.

1998 ◽  
Vol 41 (3) ◽  
pp. 284-287
Author(s):  
S. Videla ◽  
C. Isaacs ◽  
M. Cristina Diez

Wastewater from a hardboard mill characterized by a high organic content (15-30 g/L COD) was studied in a bench scale sequential aerated system in order to define a start up strategy. Inlet COD concentration varied from 0.5 to 25 g/L and the hydraulic retention time was maintained at 5 days. The sequential system proposed could reduce BOD, COD, TSS and phenol over 90% except when the inlet COD concentration was lower than 25 g/L.


2021 ◽  
Vol 7 (2) ◽  
Author(s):  
Novirina Hendrasarie ◽  
Firra R ◽  
Raden H Kokoh ◽  
Andika Andika

Limbah batik memiliki kandungan organik dan warna, yang sulit untuk digredasi. Tujuan penelitian ini mengembangkan teknologi Sequenching Batch Reactor (SBR) yang dimodifikasi dengan adsorben dari tempurung kelapa dan bamboo. Konsentrasi limbah batik awal, untuk COD sebesar 1965 mg/L, warna 1603 mg/L, TSS 1140 mg/L. Pelaksanaan penelitian terbagi menjadi dua tahap, yaitu tahap pertama limbah diolah menggunakan proses koagulasi dan flokulasi, selanjutnya tahap dua menggunakan Sequencing Batch Reactor. Pada tahap koagulasi-flokulasi, menggunakan koagulan PAC (Poly Aluminium Chloride). Sedangkan pada tahap dua yang menggunakan SBR, diatur Hydraulic Retention Time (HRT) dan berat adsorben (tempurung kelapa, bamboo dan zeolite). Hasil penelitian, didapatkan proses koagulasi dan flokulasi mampu menurunkan kandungan organic (BOD5 dan COD) pada kisaran 80%, Total Suspended Solid (TSS )26% dan warna 55%. Sedangkan pada SBR, didapatkan bahwa penambahan adsorben mengoptimalkan pendegradasian kandungan organic. Didapatkan pada HRT optimal 48 jam, jenis adsorben tempurung kelapa optimal menurunkan kandungan BOD5 sebesar 93%,  COD 93.7% sebesar , TSS 81% mg/L dan warna 81% mg/L.  Kata kunci: kandungan organic dan warna, koagulasi dan flokulasi, sequencing batch reactor (SBR).  The organic content and color of batik wastewater make it difficult to grade. The goal of this research was to create a modified Sequenching Batch Reactor (SBR) using adsorbents made from coconut shells and bamboo. The initial concentrations of COD, color, and TSS in batik wastewater were 1965 mg/L for COD, 1603 mg/L for color, and 1140 mg/L for TSS. The research was divided into two stages, with the first stage involving the use of coagulation and flocculation processes, and the second stage involving the use of a Sequencing Batch Reactor. PAC (Poly Aluminum Chloride) coagulant was used for the coagulation-flocculation stage. Meanwhile, the Hydraulic Retention Time (HRT) and the weight of the adsorbent (coconut shell, bamboo, and zeolite) were set in the second stage using SBR. The coagulation and flocculation processes reduced organic content (BOD5 and COD) by 80 %, total suspended solids (TSS) by 26 %, and color by 55 %, according to the results. In SBR, it was discovered that adding an adsorbent improves the decomposition of organic material. The optimal type of coconut shell adsorbent reduced the level of BOD5 by 93 %, COD by 93.7 %, TSS by 81 % mg/L, and color by 81 % mg/L at an optimal HRT of 48 hours. Keywords: Organic material and color, coagulation and flocculation, sequencing batch reactor (SBR).


2018 ◽  
Vol 38 (2) ◽  
pp. 160 ◽  
Author(s):  
Istna Nafi Azzahrani ◽  
Fanny Arivia Davanti ◽  
Ria Millati ◽  
Muhammad Nur Cahyanto

In this study, experiments were conducted to investigate the effect of hydraulic retention time (HRT) and organic loading rate (OLR) on process stability of nata de coco wastewater anaerobic treatment using semi-continuous digester. The standard-rate anaerobic digester with working volume of 8.5 L was used to investigate the effect of three different hydraulic retention times (15, 20, and 25 days), and a standard-rate anaerobic digester with working volume of 9.1 L was operated at different organic loading rates of 0.5, 1, and 1.5 g/L/day. The findings revealed that minimum HRT for nata de coco wastewater anaerobic treatment using semi-continuous digester was achieved at HRT 20 days. Based on data from this study, the reduction of organic content in nata de coco wastewater increased when OLR increased until 1 g/L/day. But then those parameters value decreased when OLR being increased further to 1.5 g/L/day. It showed that at 1.5 g/L/day the amount of substrate fed to the system was exceeding the total degradation capacity of methanogenic microorganisms, hence the organic overload happened and decreased the efficiency of organic content reduction in anaerobic treatment of nata de coco wastewater.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Irma Ilham Yadaturrahmah ◽  
Novirina Hendrasarie

Saat ini usaha industri tahu sedang berkembang. Limbah yang dihasilkan dari industri tahu akan menjadi suatu permasalahan bagi lingkungan. Pengolahan air limbah industri tahu dapat dilakukan dengan cara pengolahan biologis karena dapat menurunkan kandungan organik pada air limbah tahu.  Salah satu teknologi pengolahan limbah yang efektif dan efisien adalah Sequencing Batch Reactor (SBR).  Prinsip operasi SBR adalah mengisi dan menarik (fill and draw), yang terdiri dari lima tahap yaitu pengisian (fill), reaksi (reaction), pengendapan (settle), pembuangan air olahan (decand) dan pembuangan lumpur (idle).  Penelitian ini bertujuan untuk mengetahui kinerja SBR dengan penambahan impeller pada fase aerobik dalam menurunkan kandungan BOD, PO4 dan N Total pada air limbah tahu. SBR dioperasikan dengan waktu retensi hidrolik (HRT) dan kecepatan pengadukan yang bervariasi, yaitu masing-masing sebesar 24, 36 jam dan 48 jam serta kecepatan pengadukan sebesar 50, 100 dan 150 rpm. Dari hasil penelitian didapatkan HRT dan kecepatan pengadukan optimum, yaitu masing-masing sebesar 48 jam dan 150 rpm. Dengan efisiensi penyisihan BOD, PO4 dan N Total yang dihasilkan, masing-masing sebesar 93,33%, 90,97% dan 93,73%. Kata kunci: air limbah tahu, impeller, kecepatan, pengadukan, Sequencing Batch Reactor (SBR), waktu retensi hidrolik (HRT).  Currently the tofu industry is growing. The waste produced from the tofu industry will be a problem for the environment. Tofu industrial wastewater treatment can be done by biological treatment because it can reduce the organic content in tofu wastewater. One of the effective and efficient waste treatments is Sequencing Batch Reactor (SBR). The principle of operation of the SBR is fill and draw, which consists of five stages, fill,, reaction, settle, decand and idle. This study aims to see the performance of SBR with the addition of an impeller in the aerobic phase in reducing the content of BOD, PO4 and Total N in tofu wastewater. SBR is operated with a hydraulic retention time (HRT) and varying stirring speeds, namely 24, 36 and 48 hours respectively and stirring speeds of 50, 100 and 150 rpm. The results showed that the optimal HRT and stirring speed were 48 hours and 150 rpm, respectively. With the efficiency of BOD, PO4 and Total N removal produced, respectively 93,33%, 90,97% and 93,73%. Keywords: Hydraulic Retention Time (HRT), impeller, Sequencing Batch Reactor (SBR), speed, stirring, Tofu Industrial Wastewater. 


1995 ◽  
Vol 32 (7) ◽  
pp. 135-142
Author(s):  
E. Görgün ◽  
N. Artan ◽  
D. Orhon ◽  
R. Tasli

Effective nitrogen removal is now required to protect water quality in sensitive coastal areas. This involves a much more difficult treatment process than for conventional domestic sewage as wastewater quantity and quality exhibits severe fluctuations in touristic zones. Activated sludge is currently the most widely used wastewater treatment and may be upgraded as a predenitrification system for nitrogen removal. Interpretation of nitrification and denitrification kinetics reveal a number of useful correlations between significant parameters such as sludge age, C/N ratio, hydraulic retention time, total influent COD. Nitrogen removal potential of predenitrification may be optimized by careful evaluation of wastewater character and the kinetic correlations.


1992 ◽  
Vol 26 (9-11) ◽  
pp. 2327-2329
Author(s):  
J. Lee ◽  
B. Chen ◽  
H. E. Allen ◽  
C. P. Huang ◽  
D. L. Sparks ◽  
...  

A major problem in site remediation is frequently the lack of appropriate standards for pollutants in soil. Lack of standards for an exposure route can result in subjective judgments regarding the extent of remediation needed. These problems are particularly important when considering the potential for groundwater contamination by inorganic materials. The partitioning of trace metals is highly dependent on the nature of the soil and on the solution pH. The maximum level of metal in soil for which the equilibrium soluble metal does not exceed the drinking water standard can be computed, at any pH, from the measured partition coefficient for any metal and soil. The sorption of cadmium and lead onto major types of New Jersey soil has been determined as a function of pH. As the pH decreased, the amount of adsorbed metal decreased. As is conventionally done, we have transformed these data into sorption coefficients (Kd) which are a function of pH. To apply such data in the decision making process, it is necessary to use the Kd and appropriate conditions of soil/groundwater in the environment. The calculation determines the maximum concentration of metal which will not result in exceedence of water quality standards. Thesecriteria can be used as a soil standard which will be protective of groundwater quality. We developed adsorption/desorption relationships in the form of a mathematical model and computed the maximum level of metal in soil for which the equilibrium soluble metal will not exceed the drinking water standards.


1995 ◽  
Vol 31 (12) ◽  
pp. 267-273 ◽  
Author(s):  
B. S. O. Ceballos ◽  
A. Konig ◽  
B. Lomans ◽  
A. B. Athayde ◽  
H. W. Pearson

A single full-scale primary facultative pond in Sapé, north-east Brazil was monitored for performance and efficiency. The pond had a hydraulic retention time of 61 days and achieved a 95% BOD5 removal efficiency and had no helminth eggs in the effluent. The effluent failed to meet the WHO faecal coliform guideline for unrestricted irrigation. The pond was dominated by the cyanobacterium Microcystis and gave better than predicted orthophosphate removal. Details of how the system could be simply upgraded utilizing the same land are discussed.


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