scholarly journals Organic by-products of Drinking Water Chlorination

2013 ◽  
Vol 1 (3) ◽  
pp. 143-156 ◽  

<p>Chlorination of drinking water leads to the formation of a variety of Disinfection By-Products (DBPs) that may have adverse health effects on humans. Research on this subject has been continued and new epidemiological and toxicological studies have been conducted. This review summarizes factors affecting DBP formation and predictive equations proposed for it, physical and chemical properties, environmental fate, actual measurements of these compounds and technologies for controlling them, as well as regulation and currently proposed changes of their Maximum Contaminant Levels (MCLs) after evaluation by EPA of new data available.</p>

2018 ◽  
Vol 162 ◽  
pp. 05008
Author(s):  
Iman Hussein Zainulabdeen

This study was conducted to demonstrate the difference between drinking water quality for seven different areas of Kirkuk city with the treatment water in the main and three sub storages tanks, affected with drinking water pipe lines, supplying system Alternate and continuous and also pipes across the construction work’s areas. The physical and chemical properties (turbidity, pH, conductivity, Alkalinity, Total hardness, calcium, magnesium, chloride, sulfate, TDS (Total dissolve solids), TSS (Total suspended solids), sodium and potassium) for raw water and treated water in the Storages in addition to the supplying water from seven different areas in Kirkuk were analyzed, samples taken at a rate nine times during the month of March. Results showed that Drinking water of Dumez, Wasti, Shorja, Imam Qasim and Arubaa polluted with turbidity with an average levels of (8.68, 6.04, 7.41, 6.95, 7.64) NTU respectively, over the limit allowed by IBWA (International Bottled Water Association), 2012 and WHO (World Health Organization), 2006. The turbidity in the main and sub storages have reached (4.04, 4.09, 4.47, 4.16) NTU respectively, while other physical and chemical properties were within the allowed limits for human use. The pollution in those areas caused by the alternative supplying system of treatment water and it has negative impact on the pipelines, it includes constriction work in areas also where pipelines exist.


Clay Minerals ◽  
2009 ◽  
Vol 44 (1) ◽  
pp. 135-155 ◽  
Author(s):  
R. L. Parfitt

AbstractThe literature on the formation, structure and properties of allophane and imogolite is reviewed, with particular emphasis on the seminal contributions by Colin Farmer. Allophane and imogolite occur not only in volcanic-ash soils but also in other environments. The conditions required for the precipitation of allophane and imogolite are discussed. These include pH, availability of Al and Si, rainfall, leaching regime, and reactions with organic matter. Because of their excellent water storage and physical properties, allophanic soils can accumulate large amounts of biomass. In areas of high rainfall, these soils often occur under rain forest, and the soil organic matter derived from the forest biomass is stabilized by allophane and aluminium ions. Thus the turnover of soil organicmatter in allophanicsoils is slower than that in non-allophanicsoils. The organic matter appears to be derived from the microbial by-products of the plant material rather than from the plant material itself. The growth of young forests may be limited by nitrogen supply but growth of older forests tends to be P limited. Phosphorus is recycled through both inorganic and organic pathways, but it is also strongly sorbed by Al compounds including allophane. When crops are grown in allophanic soils, large amounts of labile P are required and, accordingly, these soils have to be managed to counteract the large P sorption capacity of allophane and other Al compounds, and to ensure an adequate supply of labile P. Because of their physical and chemical properties, allophanic soils are excellent filters of heavy metals and pathogens.


2021 ◽  
Vol 8 (7) ◽  
pp. 214-220
Author(s):  
Long Tong ◽  
◽  
Hongyan Li ◽  
Xiaoming Liu ◽  
Bin Li ◽  
...  

The continuous obstacle of Dictyophora indusiata has become the one of the main factors affecting the healthy development of D. indusiata industry. In order to study the effects of continuous cropping of D. indusiata on the soil environment, four treatments were used in this study: no planted (CK), planted for 1 years (1Y), continuous cropping for 2 years (2Y) and continuous cropping for 3 years (3Y), to determined of the yield of D. indusiata, soil physical and chemical properties, microbial content and enzyme activity. The results showed that the yield and soil pH value decreased with the increase of continuous cropping years, and the contents of organic matter, total nitrogen, total phosphorus and total potassium, C/N and C/P also increased with the increase of continuous cropping years. Soil availability decreased with the increase of continuous cropping years, the content of alkaline nitrogen, available phosphorus and available potassium decreased by 12.25%, 28.91% and 24.86% at 3Y compared with 1Y, respectively. The biomass of bacteria, actinomycetes and fungi and the total amount of microorganism in soil increased at 1Y compared with CK, but with the increase of continuous cropping years, the biomass of bacteria and actinomycetes and the total amount of microorganism decreased significantly, while the biomass of fungi increased significantly; the continuous cropping of D. indusiata also decreased the value of bacteria/fungi in soil. The enzyme activities of the soil were higher than those of the unplanted plots, however, the activities of urease, catalase, peroxidase, sucrase, phosphatase and protease decreased with the increase of continuous cropping years. In a word, with the increase of continuous cropping, the acidity of rhizosphere soil increased, the availability of soil nutrients and the activity of soil enzymes decreased, the biomass of soil microorganisms, bacteria and actinomycetes decreased. However, the increase of fungal biomass led to the decline of soil texture.


Sign in / Sign up

Export Citation Format

Share Document