Study on high-strength anaerobic landfill leachate treatability by membrane bioreactor coupled with reverse osmosis

One of the most important concerns in Tehran municipal landfill is the production of leachate and its potential for water resources pollution, this study was undertaken to examine feasibility of biological and physico/chemical treating of high-strength landfill leachate that was collected from Tehran municipal landfill. Average COD of the leachate in aerobic submerged membrane bioreactor is 68000 mg/L. The reactor with a working volume of 175 L, having membrane module [Hollow fiber] with pore size of 0.1 microm coupled with reverse osmosis with pore size of 0.001 micron was used in this study. The dissolved oxygen [DO] concentration was maintained at 3.2 mg/L and solid retention times [SRTs] and hydraulic retention times [HRT] were controlled at 55 and 15 days respectively, the average Membrane Bioreactor effluent COD was 1733 mg/L with average removal efficiency of 97.46%. The average NH4 -N removal efficiencies was 99%. On the other hand, an almost complete nitrification was achieved during this period. PO[4] -P concentration in the effluent was low and its average removal efficiency was as high as 90%; especially during the operation period. The averages reverse osmosis [RO] effluent COD was 335 mg/L with average removal efficiency of 99.13%. PO[4]-P concentration in the RO effluent was 0.86 mg/L and its average removal efficiency was 99.33%. The use of Membrane technologies, more especially reverse osmosis offers the best solution of achieving full purification with average COD removal efficiency of 99% and solving the problem of water resources pollution

Comparison of adsorption process by GAC with novel formulation of coagulation-flocculation for color removal of textile wastewater

This study evaluates the effectiveness of adsorption process by Granular Activated Carbon [GAC] compared with a novel formulation of coagulation - flocculation process for dye removal from textile wastewater. In this regard, acidic, reactive, disperse and direct red dye are used to prepare the synthetic dye. Dominant wave length for each dye is determined by spectrophotometeric method. Using GAC as adsorbent, equilibrium time and adsorption isotherm of each dye are determined with aid of spectrophotometric method. The results show that GAC can not remove dispersed red dye. Acidic red, direct red and reactive red of 5 mg/L concentration are removed by GAC up to 90%, 88% and 43% in 30, 60 and 120 min. [equilibrium time] respectively. Dyes of 50 mg/L concentration are removed up to 93%, 30% and 51% in 15, 90 and 150 min. respectively. Adsorption obeys Freundlich isotherm for acidic red, BET isotherm for direct red and Langmuir isotherm for reactive red. This investigation presents a novel formulation of coagulation - flocculation for color removal from textile dye solutions and illustrates its efficiency. Novel formulation of coagulation - flocculation remove direct red, reactive red and disperse red of 5 mg/L concentration respectively up to 93%, 91.3% and 57.1%. Also the mentioned dyes of 50 mg/L are removed respectively up to 90.8%, 91.9% and 70.1%

[Study of arsenic presence in drinking water sources: a case study]

Conducted studies about arsenic have shown that consumption of water contaminated with arsenic can causes different adverse health effects in consumers. World Health Organization [WHO] has enacted 10mg/L arsenic in drinking water as a guideline value. Regarding some reports about arsenic presence in a village of Hashtrood county and related health effects and also considering this fact that determination of arsenic as a poisoning chemical is not included in routine monitoring of water by responsible organizations, in present study all of drinking water sources in Hashtrood county in East Azerbaijan province were studied for arsenic presence. Water supply and its sanitation situation were studied in all of cities and residential villages [200 villages] by field visiting. Arsenic content of water samples were determined using Ez arsenic test kit, a product of Hach Company. For assurance of the kit results, 20 water samples with different concentration of arsenic were analyzed using Inductively Coupled Plasma [ICP] method and then achieved results was compared together. Arsenic was present in drinking water of 50 villages that in 9 villages its level was higher than Iranian standard [50mg/L]. During the study totally 11087 persons [21.96% of rural areas population] in Hashtrood county were exposed to different levels of arsenic via drinking water. Correlation between kit and ICP results was significant [R2 = 0.9715]. Studied region in present study is a polluted area to arsenic by geogenic sources. It is necessary to replace water source of villages with higher level than national standard with safe drinking water. Annually measurement of arsenic in drinking water of all villages spatially polluted villages should be considered by responsible organization e.g. Health Network and Rural Water and Wastewater Company. Used kit in our study is recommendable for this purpose

study of feasibility for water purification using vertical porous concrete filter

There is a need to find cheaper and simpler techniques for rural water filtration system in developing countries. Using a filter made of blocks for the water treatment enables one to make vertical filters. It is expected that the amount of land utilized would decrease by more than 70% if vertical filters were used. The operation and washing would be simpler than using horizontal sand filters as filters made of blocks would be used instead. The feasibility study focused on finding adequate materials, compositions and methods of making a block with enough resistance to water pressure, sufficient porosity for water transformation, and using inexpensive, readily available materials. A pilot study was used to determine an appropriate thickness. Testing the porous filter in another pilot study using the low overflow rate of river water showed biological growth in that media and an adequate efficiency of about 90-100% was obtained for decreasing the coliform bacteria. Washing in this filter is possible. The amount of water necessary for backwashing is 2.9% of total amount of water, which is passed

Environmental study on discharged wastewater of albourz industerial city

The treatment facility of Albourz Industrial City was established in 1999 at the southeast of Albourz Mountain with an area of 200, 000 square meters. Currently, 40, 000 cubic meters of industrial wastes are treated daily utilizing biological method of activated sludge up to the second phase without chlorination in this treatment facility. Then, the discharged wastes are directed toward the lower agricultural lands. The environmental status of the region was investigated by testing the impact of wastewater and agricultural products in four tries. In two tries, the levels of COD and BOD were higher than the environmental standards, but there was no trace of heavy metal contamination in any of the tests. In order to make inquiry about the general health of the residents and domesticated animals, a questionnaire for the farmers and animal of husbandmen was prepared. The residents were dissatisfied with the utilization of wastewater for their domesticated animals. However, farmers were content and satisfy due to their need to compensate the shortage of cultivation water with the freely available discharged wastewater of the industrial city. Because there is no enough water in Iran, they have to buy water from tankers. In the other way wastewater of Albourz industrial city had some metals and mineral materials, so it effected on growth of agricultural product, this shows a little bit of metals and mineral materials is useful for plants. An inquiry about the status of public health and diseases transferred by water was conducted and local physicians were interviewed and statistical data was collected. The number of reported cases of cholera and typhoid was low, but the number of parasitic disease cases due to remains of human waste in water was quite high. Approximately, most of the local residents were suffering from stomachaches related to parasitic disease and physical weakness. It is recommended that the Department of the Environment conduct educational programs for the employees of Industrial Cities in order to persuade them on the benefits of mandatory chlorination process in the treatment facility for the sake of employees and public health. Meanwhile, related laboratory tests to be followed up and studied by pertinent organizations to ensure proper management and planning of the discharged wastewater resources; the wastewater is a valuable source of irrigation water