708
T. Liao et al.
process are very important to arsenic removal, which have close connection with the
reaction time and pH. It is consistent with range analysis of orthogonal experiment.
Keywords Waste acid · Orthogonal experiment · Adsorption coprecipitation
Introduction
Arsenic is an acutely harmful element, chronic exposure to as causes severe illness
such as cancer. Arsenic contained in minerals enters metallurgical system, during
the smelting process of metal. Acidic wastewater containing arsenic known as waste
acid is obtained from washing and purifying smelting flue gas [1–4]. Waste acid
directly drained without removal arsenic has considerable damage to the ecological
environment and could cause irreversible harm to the human. Effective treatment of
removal arsenic from waste acid is imperative [5–8].
At present, a variety of methods have been used to remove arsenic from waste acid,
absorption, sedimentation, ion exchange, filtration, and so on [9, 10]. In the industrial,
two common methods of removing arsenic from waste acid are precipitation method
and sulfurized method. Precipitation method is safe and economical but produces
a large amount of sludge needing further disposal. Sulfurized method reduces the
amount of reagent added. But it produces toxic gases and is costly. Both two methods
are multi-stage processes [11–14]. In the paper, the method of removing arsenic from
waste acid by adding Fe and CuSO 4 , is used for study.
Orthogonal test design is a design method for studying multi-factor and multilevel. It is based on the orthogonality to select some representative points from the
comprehensive test. These representative points are uniformly dispersed and neatly
comparable. The orthogonal design can study factors simultaneously in a single set
of experiments with fewer experimental units. By analyzing the results of orthogonal
experiments, the main influencing factors and optimal experimental conditions can
be obtained. It has been extensively used in various fields due to its efficiency and
analysis result [15, 16]. Therefore, orthogonal experiment was used in this paper to
analyze the effects of different factors on the method. By analyzing the results of
orthogonal experiments, the primary and secondary factors were distinguished and
the optimal experimental conditions were determined in this paper. The experimental
mechanism was also explored in this paper, which laid the foundation for practical
application.
T. Liao et al.
process are very important to arsenic removal, which have close connection with the
reaction time and pH. It is consistent with range analysis of orthogonal experiment.
Keywords Waste acid · Orthogonal experiment · Adsorption coprecipitation
Introduction
Arsenic is an acutely harmful element, chronic exposure to as causes severe illness
such as cancer. Arsenic contained in minerals enters metallurgical system, during
the smelting process of metal. Acidic wastewater containing arsenic known as waste
acid is obtained from washing and purifying smelting flue gas [1–4]. Waste acid
directly drained without removal arsenic has considerable damage to the ecological
environment and could cause irreversible harm to the human. Effective treatment of
removal arsenic from waste acid is imperative [5–8].
At present, a variety of methods have been used to remove arsenic from waste acid,
absorption, sedimentation, ion exchange, filtration, and so on [9, 10]. In the industrial,
two common methods of removing arsenic from waste acid are precipitation method
and sulfurized method. Precipitation method is safe and economical but produces
a large amount of sludge needing further disposal. Sulfurized method reduces the
amount of reagent added. But it produces toxic gases and is costly. Both two methods
are multi-stage processes [11–14]. In the paper, the method of removing arsenic from
waste acid by adding Fe and CuSO 4 , is used for study.
Orthogonal test design is a design method for studying multi-factor and multilevel. It is based on the orthogonality to select some representative points from the
comprehensive test. These representative points are uniformly dispersed and neatly
comparable. The orthogonal design can study factors simultaneously in a single set
of experiments with fewer experimental units. By analyzing the results of orthogonal
experiments, the main influencing factors and optimal experimental conditions can
be obtained. It has been extensively used in various fields due to its efficiency and
analysis result [15, 16]. Therefore, orthogonal experiment was used in this paper to
analyze the effects of different factors on the method. By analyzing the results of
orthogonal experiments, the primary and secondary factors were distinguished and
the optimal experimental conditions were determined in this paper. The experimental
mechanism was also explored in this paper, which laid the foundation for practical
application.