The Use of Chalcedonite as a Biosorption Bed in the Treatment of Groundwater

Abstract

The conducted laboratory tests allowed determination of the efficiency of removing ammonium nitrogen, iron, and manganese in the biofiltration process on chalcedonite beds. The process of water purification was carried out by a single- and two-stage biofiltration method with gravitational and anti-gravitational flow. The study examined the extent to which chemical activation of the bed with potassium manganese (VII) affects the course of the nitrification process and the rate of biofilm formation. The obtained test results indicate that two-stage biofiltration, with initial chemical activation at the first stage of biofiltration, is an effective method for purifying waters with an abnormal content of ammonium nitrogen with simultaneous removal of iron and manganese. Activation of the bed had an effect on, among other things: biofilm formation time, efficiency of removing manganese (II) ions, and oxygen consumption in the biofiltration process. Due to the longer maturation time of the activated bed, the normative value of ammonium nitrogen (< 0.39 N-NH4+) was obtained on the 23rd day of the operation of the filters, and in the non-activated bed on the 14th day. The method of bed preparation did not affect the efficiency of removal of iron compounds.

The Impact of Microstructure of Filtration Materials on Its Auto-Activation for Manganese Removal from Groundwater

“…• fine mesopore volume (~2-5 nm) • SSA The impact of structural parameters of the filtration materials on the auto-activation process was the subject of previous studies [5,19]. The results of this study show that both the auto-activation time and the magnitude of the removal zone decrease with increasing pore volume and SSA (Figure 5).…”

“…Mined chalcedonite is a sedimentary rock formed from dissolution, precipitation, and crystallization, derived from dead organisms living in warm and shallow seas. Similar to silica sand, chalcedonite is chemically homogenous and consists mostly of SiO 2 but is characterized by internal porosity in contrast to silica sand [5,19]. Chalcedonite is a mineral which occurs in the form of solid rock formations interleaved with chalcedonite silt; hence, the technology for the preparation of chalcedonite filter sand includes, among others, mechanical crushing and grinding of this mineral, rinsing and hydraulic classification, drying and dry fractionation [6,19].…”

The Influence of the Biofiltration Method on the Efficiency of Ammonium Nitrogen Removal from Water in Combined Sorption and Nitrification Processes

“…For the first phase of the process, 3.43 mgO 2 /mgN is needed, while for the second phase, where the nitrite ion is oxidized to nitrate, the amount is 1.14 mgO 2 /mgN. It has been repeatedly confirmed that oxygen consumption is lower and is not stoichiometric to the amount of nitrogen removed [35]. The reason for this phenomenon may be, among others, a biosynthetic process during which oxygen is released.…”

Mineral Materials Coated with and Consisting of MnOx—Characteristics and Application of Filter Media for Groundwater Treatment: A Review

“…Quartz sand or gravel are the most popular materials used in field operations based on natural coating [29,165,166,176,178,[182][183][184]. Among the less frequently used mineral filter media clinoptilolite [185], anthracite [167,183], or chalcedonite [128,186,187] can be mentioned. However, during the filtration of aerated water, the grains of filter media are gradually covered with iron and manganese oxyhydroxides.…”