HEAVY METAL REMOVAL FROM INDUSTRIAL WASTEWATER USING PINECONE
SEED POWDER AND ALUMINUM CHLORIDE-BASED HYBRID NATURAL/CHEMICAL COAGULATION
Journal: Water Conservation and Management (WCM)
Author: Mohammed Shadi S. Abujazar, Salem S. Abu Amr, Motasem Y. D. Alazaiza, Ahmed Albahnasawi, Madhusudhan Bangalore Ramu
Print ISSN : 2523-5664
Online ISSN : 2523-5672
This is an open access article distributed under the Creative Commons Attribution License CC BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
Doi: 10.26480/wcm.01.2025.40.48
Abstract
This study presents an innovative strategy combining Pinecone Seed powder (PSP) and aluminum chloride (AlCl3) to remove heavy metals from industrial wastewater, optimizing PSP/AlCl3 quantities and pH levels, identifying a 3:1 (g/g) dose ratio as most effective with efficiencies of 86.47% for COD, 91.85% for color, 99.00% for TSS, 93.62% for NH3-N, and 98.49% for Mn, among others, while maintaining a pH of 8, demonstrating the sustainability of the PSP/AlCl3 coagulation technique, though further research is needed for scalability and practical application.
Keywords
Coagulation, heavy metals, combined, PSP/AlCL3, wastewater treatment
1. INTRODUCTION
The growth of socioeconomic behavior and the expansion of people, combined with the constricted availability of water due to climate change and human actions, have given rise to conflicts regarding the allocation of water resources (Yuan et al., 2023; Zuo et al., 2023; Morán-Valencia et al., 2023); consequently, the task of managing water resources has grown increasingly intricate, as the fast increase of industries contributed to a substantial effect in the worldwide spending of water (Ke et al., 2022), with this industrial advancement predominantly driving the expansion of chemical sectors, leading to an upsurge in water pollution problems across nations (Issakhov et al., 2023), as the release of wastewater from these chemical industries constitutes a substantial origin of water contamination, and although industrial effluents usually undergo some treatment, their attributes differ based on the specific production methods and raw materials, generally consisting of suspended solids ranging from 300 to 400 mg/L (Ifeanyi et al., 2012), while specific industries discharge highly polluted wastewater containing organic contaminants and heavy metals (Mao et al., 2022), prompting various technologies to tackle this challenge, notably the coagulation-flocculation method, which has surfaced as the prevalent and economically viable strategy for treating wastewater (Metin and Çifçi, 2023), alongside other alternative technologies like adsorption membrane filtration, ion exchange (Chakraborty et al., 2022), advanced oxidation processes, and more (Tan et al., 2022; Elmoutez et al., 2023; Lanzetta et al., 2023); hence, a pressing need exists to formulate efficient techniques to immobilize or eliminate heavy metals to curtail their adverse impacts (Ifeanyi et al., 2012), with coagulation-flocculation procedures capturing substantial technical attention owing to their impressive efficiency, cost-effectiveness, simplicity of deployment, and the diverse array of coagulants accessible (Abujazar et al., 2023), applied across numerous industries, including textiles, iron and steel, chemicals, pharmaceuticals, and petrochemicals (Ejimofor et al., 2020), using strongly positively charged metallic coagulants such as ferric sulfate, aluminum sulfate, and ferric chloride (Pang et al., 2011; Abujazar et al., 2022; Abujazar et al., 2022), although this strategy has drawbacks like high import costs, sludge production, and pH level variations (Abujazar et al., 2022), prompting the use of natural coagulants instead of inorganic chemicals as a practical method for handling various industrial effluent (Owodunni and Ismail, 2021), with studies highlighting natural coagulants extracted from plants like date seeds, water hyacinth, moringa seeds, locust bean seeds, olive seeds, rosehip seeds, and other substances (Abujazar et al., 203; Šćiban et al., 2005; Yongabi, 2010; Karaağaç et al., 2022; Abujazar et al., 2022; Abujazar et al., 2022; Madrona et al., 2017), which have shown high performance in wastewater treatment and stand as environmentally friendly, cost-effective options (Yang et al., 2019), driving efforts to develop effective organic-inorganic hybrid strategies that enhance inorganic coagulants by introducing innovative natural polymeric materials (El-Gaayda et al., 2021; Iloamaeke and Julius, 2019; Owodunni et al., 2023; Shabanizadeh and Taghavijeloudar, 2023), and aligned with this view, the current investigation evaluated the efficacy of a hybrid coagulation process combining natural and chemical wastewater treatment agents to identify optimal pH and dosage requirements necessary for the best performance of a Pinecone Seed Powder and Aluminum Chloride-based hybrid natural/chemical coagulation (PSP/AlCl3) process, aiming to produce high-quality treated water for reuse in an iron and steel factory, incorporating PSP as a natural coagulant with AlCl3 as a chemical coagulant to optimize combined effects for efficient iron wastewater treatment through synergy, alongside a comparative analysis of PSP alone versus the PSP/AlCl3 hybrid approach in pollutant and heavy metal removal efficacy.
2. MATERIALS AND METHODS
2.1 Source of Wastewater and Sample Collection
Wastewater samples were collected from the industrial factory in Karabuk City, Turkey, using the grab sampling method without any dilution, and were stored in a refrigerator at 4°C after collection to avoid any change in sample characteristics; comprehensive details regarding the wastewater’s composition can be found in Table 1, while 1 N H2SO4/NaOH solution was used for pH monitoring during sample testing.
2.2 Pinecone Seed Powder (PSP) Natural Coagulant Preparation
Carefully selected Pinecone Seeds were gathered from a forest near Karabuk University in Turkey, meticulously rinsed with distilled water to remove any adhering flesh, air-dried at room temperature, then subjected to an eight-hour drying period in an oven at 50 ± 1°C; after manual husk removal, the seeds were finely ground with a laboratory mortar, further refined using a Retsch RS 200 grinder to produce a consistent and homogeneous Pinecone Seed Powder (PSP), which was employed as a natural coagulant in the wastewater treatment process detailed in the study (refer to Fig. 1 for an illustration).
This table shows the results of water treatment with ozone over different time intervals (10, 20, 30, and 40 minutes). The concentration of ammonia (NH₃) significantly decreased from an initial concentration of 130 mg/L to 1 mg/L after 40 minutes of treatment. Nitrates (NO₃⁻) reduced from 50 mg/L to 7 mg/L, and nitrites (NO₂⁻) completely disappeared after 30 minutes. Phosphates (PO₄³⁻) dropped from 30 mg/L to 0 mg/L after 40 minutes, demonstrating the effectiveness of the process for phosphorus compounds. Other harmful components such as sulfates (SO₄²⁻), iron (Fe), and copper (Cu) also showed significant reductions over time, indicating the efficiency of ozone treatment in reducing contamination.
Now let’s visualize the data from this table in graphical form. The research results are presented in Figures 6, 7, and 8 below.
2.3 Chemicals
All the chemicals used in this study were procured from Sigma-Aldrich
Chemical Co. (St Louis, MO, USA).
2.4 Coagulation Experiments
An orbital shaker was used to conduct coagulation-flocculation experiments. To evaluate the impact of the hybrid coagulant, a 3 g/L dosage of pinecone seed (Karaağaç et al., 2022) was combined with several dosages of AlCl3 (0.5, 1, 1.5, 2, and 2.5 g). These dosages were mixed with one liter of raw wastewater in 500 ml beakers. Afterward, 200 ml of the sample was slowly poured into a 500 ml beaker on the shaker plate. Samples were mixed gently at a rate of 200 rpm for 5 minutes, followed by softer mixing at 90 rpm for 30 minutes. The beakers were then left to settle for half an hour. Contaminants were removed using Whatman filter paper to produce a clear sample. The effectiveness of different parameters, such as COD, TSS, NH3-N, and the presence of heavy metals, was assessed using this treated sample. The initial pH of the wastewater sample taken from the iron and steel industry was 8, which is also the pH at which these studies were carried out. A hybrid technique was used, integrating a chemical coagulant (AlCl3) and a natural coagulant (processed PSP) at varying doses. Additionally, the pH level was recognized as a pivotal variable. For each combination of the natural and chemical coagulants at their respective optimal concentrations, the pH was modulated to a spectrum of values from 4 to 11, accomplished using either 0.1 N NaOH or H2SO4.
2.5 Analytical Methods
The effectiveness of the hybrid coagulation/flocculation process was assessed by analyzing several crucial parameters, including COD, TSS, NH3-N, and the concentration of heavy metals present in the original pH (8) of the raw wastewater. All tests were measured using analytical techniques following the Standard Method of Water and Wastewater, as detailed in Table 2. Throughout the experimentation, the pH levels of the samples were meticulously controlled using a 1 N H2SO4/NaOH solution (Veli et al., 2021).
To calculate the removal efficiency, Equation 1 was used. This formula considers both the initial concentration of the untreated industrial wastewater sample and the industrial wastewater’s concentration after treatment.
Removal efficiency(%) = [1 − (Cf / Ci)] * 100
where Ci was the initial concentration before treatment, and Cf was the final concentration after treatment of each parameter.
3. RESULTS AND DISCUSSION
3.1 Effect of PSP/ AlCl3 Dosages
To comprehensively assess the impact of hybrid coagulation on treatment efficiency, several dosages of the hybrid coagulant were applied during wastewater treatment. This series of experiments involved the utilization of the best dosage of Pinecone Seed Powder coagulant (3 g/L) combined with varying quantities of AlCl3 as mentioned earlier, all incorporated into 1 liter of raw wastewater (Abujazar et al., 2022). These mixtures were vigorously agitated on the shaker, employing the conditions detailed in section 2.3 to pinpoint the dosage that yields the highest removal efficiency. As underscored, it is crucial to recognize that the surface charge of the coagulant can significantly influence coagulation performance, mainly because of its mass (Ramavandi and Farjadfard, 2014). The coagulation process facilitated by this hybrid coagulant primarily engages in adsorption bridging mechanisms. Pinecone Seed Powder (PSP) operates through charge neutralization as its coagulation mechanism (Ghernaout, 2020). In the PSP coagulation process context, a charge neutralization mechanism elucidates its function. Conversely, the AlCl3 coagulant, as part of the removal coagulation mechanism, undergoes hydrolysis upon introduction into the water sample.
| Pages | 49-54 |
| Year | 2025 |
| Issue | 1 |
| Volume | 9 |
