scholarly journals Determination of Dose–Response Relationship to Derive Odor Impact Criteria for a Wastewater Treatment Plant

Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 371
Author(s):  
Yan Zhang ◽  
Weihua Yang ◽  
Günther Schauberger ◽  
Jianzhuang Wang ◽  
Jing Geng ◽  
...  

Municipal wastewater treatment plants (WWTPs) inside cities have been the major complained sources of odor pollution in China, whereas there is little knowledge about the dose–response relationship to describe the resident complaints caused by odor exposure. This study explored a dose–response relationship between the modelled exposure and the annoyance surveyed by questionnaires. Firstly, the time series of odor concentrations were preliminarily simulated by a dispersion model. Secondly, the perception-related odor exposures were further calculated by combining with the peak to mean factors (constant value 4 (Germany) and 2.3 (Italy)), different time periods of “a whole year”, “summer”, and “nighttime of summer”, and two approaches of odor impact criterion (OIC) (“odor-hour” and “odor concentration”). Thirdly, binomial logistic regression models were used to compare kinds of perception-related odor exposures and odor annoyance by odds ratio, goodness of fit and predictive ability. All perception-related odor exposures were positively associated with odor annoyance. The best goodness of fit was found when using “nighttime of summer” in predicting odor-annoyance responses, which highlights the importance of the time of the day and the time of the year weighting. The best predictive performance for odor perception was determined when the OIC was 4 ou/m3 at the 99th percentile for the odor exposure over time periods of nighttime of summer. The study of dose–response relationship could be useful for the odor management and control of WWTP to maximize the satisfaction of air quality for the residents inside city.

1962 ◽  
Vol 41 (2) ◽  
pp. 268-273 ◽  
Author(s):  
Ralph I. Dorfman

ABSTRACT The stimulating action of testosterone on the chick's comb can be inhibited by the subcutaneous injection of 0.1 mg of norethisterone or Ro 2-7239 (2-acetyl-7-oxo-1,2,3,4,4a,4b,5,6,7,9,10,10a-dodecahydrophenanthrene), 0.5 mg of cortisol or progesterone, and by 4.5 mg of Mer-25 (1-(p-2-diethylaminoethoxyphenyl)-1-phenyl-2-p-methoxyphenyl ethanol). No dose response relationship could be established. Norethisterone was the most active anti-androgen by this test.


1994 ◽  
Vol 30 (4) ◽  
pp. 125-132 ◽  
Author(s):  
D. Carnimeo ◽  
E. Contini ◽  
R. Di Marino ◽  
F. Donadio ◽  
L. Liberti ◽  
...  

The pilot investigation on the use of UV as an alternative disinfectant to NaOCI was started in 1992 at Trani (South Italy) municipal wastewater treatment plant (335 m3/h). The results collected after six months continuous operation enabled us to compare UV and NaOCl disinfection effectiveness on the basis of secondary effluent characteristics, quantify photoreactivation effects, evidence possible DBP formation and assess costs.


1997 ◽  
Vol 35 (6) ◽  
pp. 63-70 ◽  
Author(s):  
Yoshimasa Watanabe ◽  
Yoshihiko Iwasaki

This paper describes a pilot plant study on the performance of a hybrid small municipal wastewater treatment system consisting of a jet mixed separator(JMS) and upgraded RBC. The JMS was used as a pre-treatment of the RBC instead of the primary clarifier. The treatment capacity of the system was fixed at 100 m3/d, corresponding to the hydraulic loading to the RBC of 117 L/m2/d. The effluent from the grid chamber at a municipal wastewater treatment plant was fed into the hybrid system. The RBC was operated using the electric power produced by a solar electric generation panel with a surface area of 8 m2 under enough sunlight. In order to reduce the organic loading to the RBC, polyaluminium chloride(PAC) was added to the JMS influent to remove the colloidal and suspended organic particles. At the operational condition where the A1 dosage and hydraulic retention time of the JMS were fixed at 5 g/m3 and 45 min., respectively, the average effluent water quality of hybrid system was as follows: TOC=8 g/m3, Total BOD=8 g/m3, SS=8 g/m3, Turbidity=6 TU, NH4-N=7 g/m3, T-P=0.5 g/m3. In this operating condition, electric power consumption of the RBC for treating unit volume of wastewater is only 0.07 KWH/m3.


Water ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1339
Author(s):  
Javier Bayo ◽  
Sonia Olmos ◽  
Joaquín López-Castellanos

This study investigates the removal of microplastics from wastewater in an urban wastewater treatment plant located in Southeast Spain, including an oxidation ditch, rapid sand filtration, and ultraviolet disinfection. A total of 146.73 L of wastewater samples from influent and effluent were processed, following a density separation methodology, visual classification under a stereomicroscope, and FTIR analysis for polymer identification. Microplastics proved to be 72.41% of total microparticles collected, with a global removal rate of 64.26% after the tertiary treatment and within the average retention for European WWTPs. Three different shapes were identified: i.e., microfiber (79.65%), film (11.26%), and fragment (9.09%), without the identification of microbeads despite the proximity to a plastic compounding factory. Fibers were less efficiently removed (56.16%) than particulate microplastics (90.03%), suggesting that tertiary treatments clearly discriminate between forms, and reporting a daily emission of 1.6 × 107 microplastics to the environment. Year variability in microplastic burden was cushioned at the effluent, reporting a stable performance of the sewage plant. Eight different polymer families were identified, LDPE film being the most abundant form, with 10 different colors and sizes mainly between 1–2 mm. Future efforts should be dedicated to source control, plastic waste management, improvement of legislation, and specific microplastic-targeted treatment units, especially for microfiber removal.


2021 ◽  
Vol 34 (01) ◽  
pp. 003-016
Author(s):  
John Michel Warner

AbstractAccording to Hahnemann, homoeopathic medicines must be great immune responses inducers. In crude states, these medicines pose severe threats to the immune system. So, the immune-system of an organism backfires against the molecules of the medicinal substances. The complex immune response mechanism activated by the medicinal molecules can handle any threats which are similar to the threats posed by the medicinal molecules. The intersectional operation of the two sets, medicine-induced immune responses and immune responses necessary to cure diseases, shows that any effective homoeopathic medicine, which is effective against any disease, can induce immune responses which are necessary to cure the specific disease. In this article, this mechanism has been exemplified by the action of Silicea in human body. Also, a neuroimmunological assessment of the route of medicine administration shows that the oral cavity and the nasal cavity are two administration-routes where the smallest doses (sometimes even few molecules) of a particular homoeopathic medicine induce the most effective and sufficient (in amount) purgatory immune responses. Administering the smallest unitary doses of Silicea in the oral route can make significant changes in the vital force line on the dose–response relationship graph. The dose–response relationship graph further implicates that the most effective dose of a medicine must be below the lethality threshold. If multiple doses of any medicine are administered at same intervals, the immune-system primarily engages with the medicinal molecules; but along the passage of time, the engagement line splits into two: one engages with the medicinal molecules and another engages with diseases. The immune system's engagement with the diseases increases along the passage of time, though the engagement with the medicinal molecules gradually falls with the administration of descending doses. Necessarily, I have shown through mathematical logic that the descending doses, though they seem to be funny, can effectively induce the most effective immune responses.


Sign in / Sign up

Export Citation Format

Share Document