Experimental Study on the Purification of High-Hardness Arsenic-

Overview

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Key numbers

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• and surface group M−OH complexation with Ca2+ and Mg2+. Both the confidence ranges of the total hardness and arsenic were
• counterparts were greater in the middle stages than in the end stages. The hardness removal rate was 69.36%, and that of arsenic was
• 53.45%, both higher than those achieved by existing adsorption filters for purifying high-hardness arsenic-containing water.
• unstable and even toxic.40−42 The arsenic treatment using waste- removal of high-hardness arsenic-containing water by sintered-
• Table 1. Characteristics and Structure of Kaolinite in Clay
• form of hydroxyl groups (Table 1). The structural functional groups on
• produced in sintered clay could remove Ca2+ and Mg2+ through porosity was, respectively, found to be 40.78%, 39.15%, and 37.29%
• chemical reactions, and generate the flocculating constituent Al(OH)3, before filtration (Table 3). The void-specific surface area was
• e, and the quantitative results are presented in Table 2. sintered-clay waste mainly consisted of hydrated aluminosilicate,
• Table 2. Component Quantitation of Sintered-Clay Waste by
• and 1.4%, respectively. Si and Al accounted for the largest proportion;
• As illustrated in Figure 1c−e and Table 2, the components of the was mechanically crushed and sieved into granules with particle sizes
• salts. SiO2 accounted for the largest proportion, ranging from 42.3% to transparent column of φ45 mm × 300 mm in three layers. The water
• 51.6%, CaMg(CO3)2 from 7.8% to 22.1%, calcium aluminosilicate from sample was taken from the Quaternary aquifer at a buried depth of 60 m
• 17.7% to 20.7%, sodium aluminosilicate from 11.9% to 29.2%, and in the south of Jiaozuo, with BOD5 ≤ 2 mg/L, CODMn ≤ 5 mg/L, 7.2 ≤
• potassium aluminosilicate at 19.8%. CaMg(CO3)2 was present as a pH ≤ 8.2, and 600 ≤ EC ≤ 1800 μS/cm. The contents of arsenic, Ca2+,
• filtered water. Sodium aluminosilicate and potassium aluminosilicate, 709.89 mg/L. The water sample was placed into a Bartensioner flask
• for 10−20, 20−40, and 40−60 mesh filter media lasted for 144, 61.99%, and 67.27% at 144, 136, and 112 h, when the adsorption
• 376, and 400 h with removal rates of 54.07−56.88%, 57.80− the filtered water was significantly lower than that in the raw
• 61.99%, and 60.14−67.27% for 10−20, 20−40, and 40−60 water, and the Mg2+ adsorption effect was significant. The
• mesh filter media. The stable purification stage then ensued. The removal rate of Mg2+ was 40−60 > 20−40 > 10−20 mesh
• because the pore specific surface area of the filter media was 40− respectively, to 35.95, 30.04, and 20.22 mg/L. This was followed
• of 10−20, 20−40, and 40−60 mesh filter media ranged from 8 to adsorption was apparent in the early part thereof. The removal
• of 10−20, 20−40, and 40−60 mesh filter media decreased to 57.94−60.59%, 57.36−63.96%, and 57.74−69.36%, respec-
• 52.17%, 55.69%, and 56.05%, with the maximum contents tively, including the partial accelerated purification stage, the
• 10−20, 20−40, and 40−60 mesh filter media was more stable mesh.
• mg/L at 16 h, and gradually increased, respectively, to 0.1066,
• The washing stage of the 10−20, 20−40, and 40−60 mesh filter and the stable purification stage ensued. The boundary points
• hardness was higher than that of the raw water due to the purification stage and the stable stage for the 10−20, 20−40, and
• 255.83, and 217.48 mg/L. In the stable deceleration purification and 40−60 mesh filter media decreased, respectively, to 27.19,
• stage, the total hardness was, respectively, 327.03−301.69, 28.29, and 29.34% at 48, 48, and 40 h, and the arsenic adsorption
• 398.58−297.74, and 285.60−291.24 mg/L. The curve of the capacity gradually increased with decreasing particle size of the
• being 60.59%, 63.96%, and 69.36%, respectively, and gradually respectively, followed by a stable purification stage. The removal
• maximum removal rates 53.93%, 57.93%, and 59.82% in the 20, 20−40, and 40−60 mesh filter media were, respectively,
• reasonable particle size of filter media was selected to match the Table 4. Component Quantification of the Filtered Sintered-
• 8. The confidence range was between the upper and lower limits CaMg(CO3)2 13.5 15.3 21.5
• of 95%. The total hardness softening started from a lower value NaAlSi3O8 / / /
• gradually during the decelerated purification stage and the stable Pb28As12S46 7.7 / 4.2
• with small differences among the three particle-size media 6.9% SiAs2 appeared. In the 40−60 mesh filtered sintered-clay
• during the deceleration and acceleration stages, but it gradually media, SiO2 increased from 45.4% to 55.0%, MgCa(CO3)2
• expanded as differences among the three particle-size media decreased slightly from 22.1% to 21.5% with no significant
• increased in the later stable stage because of the rise in arsenic change, and CaAl2Si2O8 (19.2%) and Pb28As12S46 (4.2%)

Methods (brief)

• 51.6%, CaMg(CO3)2 from 7.8% to 22.1%, calcium aluminosilicate from sample was taken from the Quaternary aquifer at a buried depth of 60 m
• filtered water. Sodium aluminosilicate and potassium aluminosilicate, 709.89 mg/L. The water sample was placed into a Bartensioner flask
• the main components for removing Ca2+ and Mg2+, could produce the and fed into the column through a hose. 1000 mL water sample was
• both the bed contact time and the replacement of the water sample in
• The curve of the Ca2+ content in the filtered water sample is purification stage, and the stable purification stage. The curve of
• Ca2+ content in the filtered water sample was higher than that in particle size, the more Ca2+ dissolution occurred in the sintered-
• media before and after filtration, the 10−20, 20−40, and 40−60 the water sample and Pb and S in the sintered-clay media. The
• time, respectively. Arsenic removal also underwent three stages: filter material, and was collected by the lower water distributor
• acid. In the reference 43, the As(V) removal rate of pyrolysis L/h and a brine water sample of 100 mL. The total hardness
• As(V) wastewater at pH 2.3, with a reaction time of 24 h and with a flow rate of 0.3−0.5 L/h and a water sample of 100 mL.

Implications

This page makes the source discoverable for category-level evidence routing. Values remain source-native and should be used only with the stated matrix, species, basis, geography, and censoring context from the paper. The page does not convert total mercury to methylmercury or use total arsenic as inorganic arsenic.

Wiki pages this source may touch

• Fish — marine, non-predatory (sardines, anchovies, salmon, cod)
• Cadmium
• Arsenic
• Aluminum
• Chromium

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Update history

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