Assessment and Removal of Heavy Metals and Other Ions from the Industrial Wastewater of Faisalabad, Pakistan

: The contamination of surface and groundwater is of major concern around the globe due to the fast industrialization and urbanization. The groundwater and water quality of rivers, Ravi and Chenab in Faisalabad, Pakistan are contaminated due to the industrial wastewater. The aim of this study was the assessment of the physiochemical contaminants of Faisalabad’s industrial wastewater area and the adsorptive removal of ions present in high concentrations following the National Environmental Quality Standards (NEQS) for the municipal and industrial liquid efﬂuents of Pakistan. One of the two samples was collected from a drain carrying wastewater from different industries and other from the outlet of a drain discharging wastewater into river Chenab. The analysis results obtained indicate that most of the contaminants were below the acceptable limit of industrial wastewater NEQS, Pakistan. However, contaminants like sulfate ions (714 mg/L), total dissolved solids (33,951–34,620 mg/L) and barium ions (11–15 mg/L) were found to be higher than the allowable level of NEQS for the municipal and industrial liquid efﬂuents for Pakistan. A novel biosorbent synthesized indigenously from Monotheca buxifolia seeds was used for the removal of sulfate, barium and TDS from the wastewater efﬂuent samples. This biosorbent successfully reduced the sulfate ion concentration in the wastewater sample from 714 to 420 mg/L at pH 6 in 1 h. Similarly, the concentration of TDS reduced to 33,951 from 6295 mg/L at pH 4, whereas barium ions were removed from 15 to 1 mg/L at pH 10 in 1 h. Treatment of wastewater through the synthesized biosorbent efﬁciently removed the high concentration ions and could potentially be applied to reduce the toxic effects of these contaminants on local public health.


Introduction
The production of waste by human activities is inevitable and a major part of these wastes often enter water as wastewater [1]. Industrial wastewater entering water sources is one of the main causes of ecological pollution as it affects the quality of drinking water, soil and aquatic environment [2]. There are several types of industrial wastewater based on the different industries and nature of pollutants. Each industrial zone generates its own specific mixture of contaminants [3]. Contamination of surface and groundwater is a growing problem due to fast industrialization and urbanization [4]. The setting up of new industries and the extension of the present industries are already producing abundant volumes of industrial waste [5]. The textiles, food, chemicals, paper and pulp, leather and tanneries, mining, metallurgy, and manufacturing products related industries are mainly responsible for industrial wastewater [6]. The boiler-feed, evaporative cooling and process water, and irrigation of grounds surrounding the industrial plant are the most common waters used by different industries [7].
The industrial wastes causing environmental contamination by trace and heavy metals and chemicals is one of the foremost health problems in industrial cities. During industrial Scheme 1. Flow diagram of the research study design.

Study Area
The study was carried out in Faisalabad's industrial area which is one of the most important industrial cities of the Punjab province of Pakistan. Faisalabad is located between two main persistent rivers, Chenab and Ravi, at 73.08′ E, 31.25′ N and at an altitude of 214 m above sea level. A map of Faisalabad and the sample collection area is shown in Figure 1a,b.

Samples Collection and Preservation
A total of two samples of wastewater were collected in polyethylene cans from the industrial area of Faisalabad, near the Sargodha road. One sample was collected from the main drain carrying the wastewater of different industries and the other sample was collected from the outlet of the main drain, passing toward agricultural land and finally into river Chenab (Figure 1c,d). After sample collection, the samples were filtered and preserved by the addition of HNO3 (pH > 2) as per standard methods [19]. Scheme 1. Flow diagram of the research study design.

Study Area
The study was carried out in Faisalabad's industrial area which is one of the most important industrial cities of the Punjab province of Pakistan. Faisalabad is located between two main persistent rivers, Chenab and Ravi, at 73.08 E, 31.25 N and at an altitude of 214 m above sea level. A map of Faisalabad and the sample collection area is shown in Figure 1a,b.

Samples Collection and Preservation
A total of two samples of wastewater were collected in polyethylene cans from the industrial area of Faisalabad, near the Sargodha road. One sample was collected from the main drain carrying the wastewater of different industries and the other sample was collected from the outlet of the main drain, passing toward agricultural land and finally into river Chenab (Figure 1c,d). After sample collection, the samples were filtered and preserved by the addition of HNO 3 (pH > 2) as per standard methods [19].

Material & Instrumental Details
All chemicals used in this research were of analytical grade. The NaOH (Merck, Darmstadt, Germany) and HNO 3 (Duksan Pure Chemicals Co. LtD, Ansan, Korea) were used for stock solution preparation with deionized water. Different glassware, filter papers, pH meter (OHAUS ST 10, Parsippan, NJ, USA), stopwatch, analytical balance (Sartorius CP323P, Gottingen, Germany), and orbital shaker (KJ-201BD, Ningbo, China) were used in adsorption studies. The different analytical techniques and instruments used for the different contaminants and heavy metals detection are shown in Table 1.

Material & Instrumental Details
All chemicals used in this research were of analytical grade. The NaOH (Merck, Darmstadt, Germany) and HNO3 (Duksan Pure Chemicals Co. LtD, Ansan, South Korea) were used for stock solution preparation with deionized water. Different glassware, filter papers, pH meter (OHAUS ST 10, Parsippan, NJ, USA), stopwatch, analytical balance (Sartorius CP323P, Gottingen, Germany), and orbital shaker (KJ-201BD, Ningbo, China) were used in adsorption studies. The different analytical techniques and instruments used for the different contaminants and heavy metals detection are shown in Table 1.

Preparation of Biosorbent
A novel biosorbent (Monotheca buxifolia seeds) was used for the removal of contaminants at high concentrations. The seeds were collected from M. boxifolia fruits and were first washed with tap water and then with deionized water to remove undesired particles. The seeds were then ground and dried in an oven at 110 • C for 24 h and the powder was preserved in an airtight bottle for adsorption studies.

Adsorption Activity
The batch adsorption technique was used for the removal of pollutants at high concentration by M. boxifolia. A stock solution was prepared by mixing equal ratios of 1 M sodium hydroxide and HNO 3 . The required solution of 0.1 M HNO 3 /NaOH was prepared from the stock solution to adjust the pH of sample solutions during the experiment. The adsorptive removal of ions was carried out at different pH, i.e., 2, 4, 6, 8, 10 and 12 by taking 50 mL of industrial wastewater in 100 mL Erlenmeyer flasks. The pH of the flasks was adjusted, using a pH meter and 0.1 M HNO 3 /NaOH mixture solution. The pH measurements were conducted at room temperature. Then, 0.1 g of biosorbent was placed in the flask and the resultant suspensions were shaken on an orbital shaker for 12 h at 110 rpm. The suspension was filtered through Whatman filter paper and the final concentration of the adsorbate species were determined by using a colorimeter, a conductivity meter, and a spectrophotometer [22,24,25].
The procedure for the study for the effect of contact time was the same as that of the pH study mentioned above; however, the suspension was shaken for time intervals, i.e., 5,10,15,20,25,30,35,40,45,50,55 and 60 mins at a fixed pH. In both cases, the amount of adsorbate, adsorbed per unit mass of M. buxifolia was calculated by the following q = (Ci − Cf) V/W × 1000, where q is the quantity of adsorbent adsorbed (mg/gm), Ci is the initial concentrations, Cf is the final concentrations (mg/L) and W is the weight of the adsorbent (gm).

Analysis of Samples
The industrial wastewater samples were analyzed as per the industrial liquid effluent NEQS with respect to the biological oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), chloride, sulfate, fluoride, cyanide, sulfide and to-  Table 2. into the water in wastes from industrial sources, such as mining and smelting operations, and paper mills. The high values of sulfate may be the result of untreated waste discharge from industries like textiles, paperboards and tanneries running in the industrial area [26]. The wastewater flowing into the different drains can pollute drinking water and agricultural land through leaching processes and will thus increase the sulfate level in surface and groundwater reservoirs.
The concentration of fluoride, cyanide and sulfide was analyzed in both the samples. The concentration of fluoride was 1.20 mg/L and 1.22 mg/L in both sample 1 and 2, respectively. It was found that sample 1 contained no cyanide or sulfide. However, in sample 2, their concentration was found to be 0.01 mg/L, as shown in Figure 2.   The concentration level of TDS ranged from 33,951 mg/L to 34,620 mg/L in the wastewater samples (Figure 3), which is in excess above from the national standards for drinking water quality (<1000 mg/L) and industrial liquid effluent NEQS (3500 mg/L). The wastewater contained high amounts of TDS because a number of industries discharging their wastewater into outwards drain. The high concentration of TDS in the wastewater samples may be attributed to the discharge of industrial effluent from numerous industries into the outward drains. The wastewater then joins the Chenab river and other water reservoirs in the vicinity of Faisalabad and this may contribute toward the water pollution due to the high concentration of TDS. Consistent records on the possible health effects related to the ingestion of TDS in drinking water do not exist, and no health-based recommendation values are suggested. However, the presence of TDS in high concentrations in drinking water may be objectionable to users [27].
The analysis of different nonmetals, namely, boron, chlorine and selenium was also carried out in this research ( Figure 3). Boron and chlorine were absent in both the samples. While selenium was not present in sample 1, but 0.16 mg/L was detected in sample 2, below the permitted limit of industrial liquid effluent NEQS. Besides the analysis of the above contaminants, the samples were also checked for the concentration of heavy metals and nonmetals, results are given in Table 3. A total 12 metals were analyzed in the wastewater of Faisalabad's industrial area. The results obtained of the metals ions concentrations are shown in Figure 4. Metalloid, arsenic ions were not present in sample 1 but were found at a concentration of 0.01 mg/L in sample 2. This concentration meets the specification of industrial liquid effluent NEQS for Pakistan. Barium is an abundant, naturally existing metal and is used for different industrial purposes. Barium compounds are used in paints, glass, drilling mud, bricks, rubber, pigments, cosmetic, pharmaceutics and ceramics. Humans are exposed to barium by ingestion and inhalation. Dissolved barium compounds in water may cause harmful health effects, such as difficulty breathing, stomach irritation, increased blood pressure, brain swelling, arrythmia, muscle weakness, and damage to the kidneys, liver, spleen, and heart [28]. The contents of barium ions ranged between 11 mg/L to 15 mg/L (Figure 4). The concentration of barium ions in wastewater exceeded the NSDWQ (0.7 mg/L) and industrial The results showed that the range of BOD, COD, TSS and chlorides in both wastewater sample varied from 74-78, 80-88, 37-47 and 638-709 mg/L, respectively ( Table 2). All these values were below the acceptable level of industrial liquid effluent (NEQS). The sulfate concentration was found to be 714 mg/L and 167 mg/L in samples-1 and -2, respectively ( Figure 2). The concentration of sulfate in sample 1 was observed to be higher than the permissible value for industrial liquid effluent NEQS (600 mg/L). Sulfate can cause water to have a bitter flavor and also have a laxative effect on humans. Sulfate enters into the water in wastes from industrial sources, such as mining and smelting operations, and paper mills. The high values of sulfate may be the result of untreated waste discharge from industries like textiles, paperboards and tanneries running in the industrial area [26]. The wastewater flowing into the different drains can pollute drinking water and agricultural land through leaching processes and will thus increase the sulfate level in surface and groundwater reservoirs.
centrations of 0.05 mg/L and 0.03 mg/L in sample 1 and 2, respectively. These values are less than the tolerable values of industrial effluent NEQS. Iron ion concentrations varied from 1.60 mg/L to 1.75 mg/L in both sample 1 and 2, respectively. These concentrations are below the industrial liquid effluent NEQS. The observed concentration levels (0.08 mg/L-0.09 mg/L) of manganese ions in both samples, were within the permissible level of industrial effluent NEQS. Nickel ion content was found to be 0.02 mg/L in sample 1, below the allowable concentration of industrial effluent NEQS and was absent in sample 2. Zinc ions quantities in the samples fell within the safe range of 0.08 mg/L to 1.11 mg/L as per the industrial effluent NEQS.    The concentration of fluoride, cyanide and sulfide was analyzed in both the samples. The concentration of fluoride was 1.20 mg/L and 1.22 mg/L in both sample 1 and 2, respectively. It was found that sample 1 contained no cyanide or sulfide. However, in sample 2, their concentration was found to be 0.01 mg/L, as shown in Figure 2.
The concentration level of TDS ranged from 33,951 mg/L to 34,620 mg/L in the wastewater samples (Figure 3), which is in excess above from the national standards for drinking water quality (<1000 mg/L) and industrial liquid effluent NEQS (3500 mg/L). The wastewater contained high amounts of TDS because a number of industries discharging their wastewater into outwards drain. The high concentration of TDS in the wastewater samples may be attributed to the discharge of industrial effluent from numerous industries into the outward drains. The wastewater then joins the Chenab river and other water reservoirs in the vicinity of Faisalabad and this may contribute toward the water pollution due to the high concentration of TDS. Consistent records on the possible health effects related to the ingestion of TDS in drinking water do not exist, and no health-based recommendation values are suggested. However, the presence of TDS in high concentrations in drinking water may be objectionable to users [27].
The analysis of different nonmetals, namely, boron, chlorine and selenium was also carried out in this research (Figure 3). Boron and chlorine were absent in both the samples. While selenium was not present in sample 1, but 0.16 mg/L was detected in sample 2, below the permitted limit of industrial liquid effluent NEQS.
Besides the analysis of the above contaminants, the samples were also checked for the concentration of heavy metals and nonmetals, results are given in Table 3. A total 12 metals were analyzed in the wastewater of Faisalabad's industrial area. The results obtained of the metals ions concentrations are shown in Figure 4. Metalloid, arsenic ions were not present in sample 1 but were found at a concentration of 0.01 mg/L in sample 2. This concentration meets the specification of industrial liquid effluent NEQS for Pakistan. Barium is an abundant, naturally existing metal and is used for different industrial purposes. Barium compounds are used in paints, glass, drilling mud, bricks, rubber, pigments, cosmetic, pharmaceutics and ceramics. Humans are exposed to barium by ingestion and inhalation. Dissolved barium compounds in water may cause harmful health effects, such as difficulty breathing, stomach irritation, increased blood pressure, brain swelling, arrythmia, muscle weakness, and damage to the kidneys, liver, spleen, and heart [28]. The contents of barium ions ranged between 11 mg/L to 15 mg/L ( Figure 4). The concentration of barium ions in wastewater exceeded the NSDWQ (0.7 mg/L) and industrial liquid effluent NEQS for Pakistan. The elevated value of barium ion discharge in industrial wastewater may be the result of plastic, rubber and glass industries working in the area. The presence of barium ions in wastewater can produce various diseases in the local population. Toxic heavy metals ions, i.e., cadmium, copper, lead, mercury, and silver were not present in both wastewater samples. Chromium ions were observed in wastewater at concentrations of 0.05 mg/L and 0.03 mg/L in sample 1 and 2, respectively. These values are less than the tolerable values of industrial effluent NEQS. Iron ion concentrations varied from 1.60 mg/L to 1.75 mg/L in both sample 1 and 2, respectively. These concentrations are below the industrial liquid effluent NEQS. The observed concentration levels (0.08 mg/L-0.09 mg/L) of manganese ions in both samples, were within the permissible level of industrial effluent NEQS. Nickel ion content was found to be 0.02 mg/L in sample 1, below the allowable concentration of industrial effluent NEQS and was absent in sample 2. Zinc ions quantities in the samples fell within the safe range of 0.08 mg/L to 1.11 mg/L as per the industrial effluent NEQS.

Effect of pH
A pH study was conducted for very low level contaminants, such as fluoride (1.20 and 1.22 mg/L), cyanide and sulfide (0.01 mg/L), arsenic (0.01 mg/L), selenium (0.16 mg/L), chromium (0.03 and 0.05 mg/L), iron (1.60 and 1.75 mg/L), manganese (0.08 L and 0.09 mg/L), nickel (0.02 mg/L), and zinc (0.08 and 1.11 mg/L), present in wastewater samples at room temperature for 12 h. All fluoride, cyanide, arsenic, selenium, chromium, iron, manganese, nickel, and zinc ions were completely removed at the pH values from 2-8. The pH study results of the contaminants such as BOD, COD, and TSS present in wastewater samples at room temperature for 12 h are given in Table 4. These results are graphically presented in Figure 5.

Effect of pH
A pH study was conducted for very low level contaminants, such as fluoride (1.20 and 1.22 mg/L), cyanide and sulfide (0.01 mg/L), arsenic (0.01 mg/L), selenium (0.16 mg/L), chromium (0.03 and 0.05 mg/L), iron (1.60 and 1.75 mg/L), manganese (0.08 L and 0.09 mg/L), nickel (0.02 mg/L), and zinc (0.08 and 1.11 mg/L), present in wastewater samples at room temperature for 12 h. All fluoride, cyanide, arsenic, selenium, chromium, iron, manganese, nickel, and zinc ions were completely removed at the pH values from 2-8. The pH study results of the contaminants such as BOD, COD, and TSS present in wastewater samples at room temperature for 12 h are given in Table 4. These results are graphically presented in Figure 5. The initial concentration of BOD ions was 74 and 78 mg/L for sample 1 and 2, respectively, whereas the initial concentration for COD was 88 mg/L for sample 1 and 80 mg/L for sample 2 and for TSS was 47 mg/L for sample 1 and 37 mg/L for sample 2. The results The initial concentration of BOD ions was 74 and 78 mg/L for sample 1 and 2, respectively, whereas the initial concentration for COD was 88 mg/L for sample 1 and 80 mg/L for sample 2 and for TSS was 47 mg/L for sample 1 and 37 mg/L for sample 2. The results of adsorptive removal of these ions at different pH depicted the lowering in concentration of these ions from wastewater during the batch adsorption process. The maximum reduction of BOD by biosorbent occurred at pH 10 from 74 to 55 mg/L for sample 1 wastewater and 78 to 55 mg/L for sample 2 wastewater at room temperature in 12 h ( Table 4). The concentration of COD dropped at pH 12 from 88-45 mg/L for sample 1 wastewater and 80 to 41 mg/L (Table 4) for sample 2 wastewater at room temperature in 12 h in adsorption process giving the good activity by biosorbent. The obtained analysis results for TSS revealed that the concentration dropped from 47-29 mg/L for sample 1 wastewater and 37 to 18 mg/L for sample 2 wastewater at room temperature at pH 10 (as enlisted in Table 4) in 12 h in batch adsorbent experiment.
A pH was study carried out for the high level contaminants (chloride, TDS, barium and sulfate ions) detected in wastewater samples at room temperature for 12 h. The results of adsorption with samples-1 and -2 are shown in Figure 6 and quantitative measurements are listed in detail in Table 5. The initial concentrations of chloride ions were 709 and 638 mg/L for sample 1 and 2, respectively and for sulfate ions was 714 mg/L for sample 1. Whereas the initial concentration of TDS was 33,951 mg/L for sample 1 and 34,620 mg/L for sample 2 and for barium ions concentrations of 11 and 15 mg/L were recorded for sample 1 and 2, respectively. The maximum adsorption level of TDS by the biosorbent took place at pH 4. While biosorbent adsorbed mostly barium ions at pH 10-12 brought the barium ions to below permissible limit. Maximum sulfate ions adsorbed by the biosorbent found with pH 6. A pH was study carried out for the high level contaminants (chloride, TDS, barium and sulfate ions) detected in wastewater samples at room temperature for 12 h. The results of adsorption with samples-1 and -2 are shown in Figure 6 and quantitative measurements are listed in detail in Table 5. The initial concentrations of chloride ions were 709 and 638 mg/L for sample 1 and 2, respectively and for sulfate ions was 714 mg/L for sample 1. Whereas the initial concentration of TDS was 33,951 mg/L for sample 1 and 34,620 mg/L for sample 2 and for barium ions concentrations of 11 and 15 mg/L were recorded for sample 1 and 2, respectively. The maximum adsorption level of TDS by the biosorbent took place at pH 4. While biosorbent adsorbed mostly barium ions at pH 10-12 brought the barium ions to below permissible limit. Maximum sulfate ions adsorbed by the biosorbent found with pH 6.

Effect of Contact Time
The effect of contact time was studied for low level contaminants such as fluoride (1.20-1.22 mg/L), cyanide and sulfide (0.01 mg/L), arsenic (0.01 mg/L), selenium (0.16 mg/L), chromium (0.03-0.05 mg/L), iron (1.60-1.75 mg/L), manganese (0.08 l-0.09 mg/L), nickel (0.02 mg/L), and zinc (0.08-1.11 mg/L), present in the wastewater samples by maintaining the optimum pH at room temperature for 5-60 min. The effect of contact time revealed that all fluoride, cyanide, arsenic, selenium, chromium, iron, manganese, nickel, and zinc ions were completely removed in the optimal pH ranges in first 45 min. The effect of contact time on the contaminants such as BOD (pH-10), COD (pH-12), TSS (pH-10), and chlorides ions (pH-10) present in the wastewater samples at room temperature for 60 min is depicted in Figure 7 and listed in detail in Table 6.

Effect of Contact Time
The effect of contact time was studied for low level contaminants such as fluorid (1.20-1.22 mg/L), cyanide and sulfide (0.01 mg/L), arsenic (0.01 mg/L), selenium (0.1 mg/L), chromium (0.03-0.05 mg/L), iron (1.60-1.75 mg/L), manganese (0.08 l-0.09 mg/L nickel (0.02 mg/L), and zinc (0.08-1.11 mg/L), present in the wastewater samples by main taining the optimum pH at room temperature for 5-60 min. The effect of contact tim revealed that all fluoride, cyanide, arsenic, selenium, chromium, iron, manganese, nicke and zinc ions were completely removed in the optimal pH ranges in first 45 min. The effe of contact time on the contaminants such as BOD (pH-10), COD (pH-12), TSS (pH-10), an chlorides ions (pH-10) present in the wastewater samples at room temperature for 60 mi is depicted in Figure 7 and listed in detail in Table 6. The initial concentration of ions was recorded before adsorptive activity was mea ured at specific pH. The contact time analysis results obtained from the batch adsorptio process at room temperature indicated that the concentration of BOD from wastewate decreased from 74 to 41 mg/L in 55 min and 78 to 47 mg/L in 60 min at optimum pH 1  The initial concentration of ions was recorded before adsorptive activity was measured at specific pH. The contact time analysis results obtained from the batch adsorption process at room temperature indicated that the concentration of BOD from wastewater decreased from 74 to 41 mg/L in 55 min and 78 to 47 mg/L in 60 min at optimum pH 10 ( Table 6) for sample 1 and sample 2, respectively, whereas for COD the concentration reduced from 88 to 40 mg/L and 80 to 35 mg/L at room temperature in 60 min at optimum pH 12 for sample 1 and sample 2, respectively, as shown in Table 6. Likewise, a decrease in the quantity of TSS by the application of the biosorbent was observed from 41 to 21 mg/L (for sample 1 wastewater) in 60 minutes' contact time and 37 to 16 mg/L (for sample 2 wastewater) in 50 minutes' contact time. The adsorption process took place at room temperature by keeping the optimal pH 10 ( Table 6).
The content of chlorides ions was reduced by the biosorbent in sample 1 from 709 to 676 mg/L at room temperature at optimum of pH 10 in 55 min. For sample 2 a decrease in chlorides ions by the application of the biosorbent from 638-600 mg/L in 55 min normal temperature at optimum pH 10 ( Table 7).
for barium ions at pH 10. The results are given in Table 7. The analysis results obtained point out that the biosorbent gradually removed the sulfate ions, TDS and barium ions (Figure 8) from the industrial wastewater samples over time. The adsorption increased with increasing of time (5-60 min). The maximum adsorption of all the high level contaminants occurred in 60 min. This novel biosorbent brought sulfate and barium ions to levels below the allowable value of the industrial liquid effluent NEQS and removed a substantial quantity of TDS from the industrial wastewater.

Conclusions
The study was based on the assessment of the heavy metals and chemicals from the industrial wastewater of Faisalabad city of Pakistan. Being the industrial hub of the city, the water resources have been densely contaminated. The analysis results obtained indi-

Conclusions
The study was based on the assessment of the heavy metals and chemicals from the industrial wastewater of Faisalabad city of Pakistan. Being the industrial hub of the city, the water resources have been densely contaminated. The analysis results obtained indicate that most of the contaminants were below the acceptable limit of the industrial effluent NEQS (Pakistan). Only 3 contaminants, i.e., sulfate ions, TDS and barium ions were found in higher concentrations than the allowable levels of the industrial wastewater NEQS. A novel biosorbent synthesized from Monotheca buxifolia seeds was used for the removal of sulfate, barium and TDS from wastewater effluent samples. This biosorbent successfully reduced sulfate ion concentration in wastewater samples from 714 to 420 mg/L at pH 6 in 1 h. Similarly, the concentration of TDS was reduced to 33,951 from 6295 mg/L at pH 4, whereas barium ions decreased from 15 to 1 mg/L at pH 10 in 1 h. The use of the biosorbent obtained from M. buxifolia seeds efficiently reduced the sulfate and barium ions to an acceptable level of the industrial liquid effluent NEQS and removed an abundant quantity of TDS from the industrial wastewater. In light of the results obtained in this study, this biosorbent could be used for the treatment of industrial wastewater that contains high concentrations of sulfate ions, TDS and barium ions before being discharged for irrigation purposes and thus also reduce the toxic effects of these contaminants on local public health.