New composite coagulant from agro-waste (tapioca peel) and polyaluminium chloride for primary landfill leachate treatment

Coagulation-flocculation is one of the applications that work efficiently for stabilised leachate treatment, alongside the utilisation of chemical coagulants. On the contrary, the use of chemical coagulants has certain drawbacks towards the health of the ecosystem and living organisms. Hence, this leads to the application of natural material (tapioca peel powder (TPP)) originated and recycled from agro-waste in this study. The limited ability of TPP as a single coagulant could be overcome by substituting the material into polyaluminium chloride (PAC) as a composite coagulant (PACTPP) with different weight ratios. PACTPP was tested on stabilised leachate taken from Simpang Renggam's landfill site (SRLS) by investigating the removal percentage of respective parameters. Based on the weight ratio optimisation, TPP/Al = 3.71 or PACTPPg was determined as the optimum composite coagulant. It was characterised that PACTPPg had combined the best benefits from PAC and TPP, with an acidic property of pH 3.45, a low charge density of 3.45 mV, a higher molecular weight of 1.59 × 107 g/mol, and a bigger particle size of 4.528 × 104 d.mn. By using scanning electron microscopy/energy-dispersive X-ray (SEM-EDX), a longer connected and compact structure was observed with a diameter of 142.3 μm, i.e., 70.1% increment from PAC. Through Fourier-transform infrared (FTIR) and X-ray diffraction (XRD) analyses, PACTPPg was identified to comprise new chemical compounds: the functional groups of ketones, aldehydes, and alkanes in a semi-formed crystalline phase. The newly formed compounds could be associated with the bridging function that becomes the predominant mechanism for PACTPPg’s coagulation behaviour in removing pollutants. Response surface methodology (RSM) was applied after using the conventional method of one-factor-at-a-time (OFAT) optimisation to find the optimum pH for the leachate sample and dosage of PACTPPg. At the optimum conditions of pH 7.13 and 2,446.18 mg/L (479.49 mg/L of Al content), the responses were 59.4% for chemical oxygen demand (COD), 23.7% for ammonia nitrogen, 91.8% for turbidity, 88.5% for colour, and 96.0% for suspended solids of removal percentages. The optimisation also revealed that the performance of PACTPPg was at par with that of PAC+TPP, PAC, and TPP coagulants, especially on the removal of physical parameters. The dosages of PACTPPg were reduced by 33.0% and 26.8% compared to the application of PAC and PAC+TPP, respectively. Meanwhile, from the flocs and sludge formation analyses, PACTPPg worked well for the treatment of landfill leachate by inducing adsorption and bridging between particles > charge neutralisation > sweep flocculation mechanisms with denser generated sludge. PAC+TPP, PAC, and TPP also underwent these kinds of mechanisms but with different superiority, which was portrayed by its percentages of parameter removal. Based on the study, it can be concluded that PACTPPg has the potential to be a sustainable coagulant for the primary treatment of stabilised raw leachate in Malaysia

Leachate treatment by conventional coagulation, electrocoagulation and two-stage coagulation (conventional coagulation and electrocoagulation)

Leachate is widely explored and investigated due to highly polluted and difficult to treat. Leachate treatment commonly involves advanced, complicated and high cost activities. Conventional coagulation is widely used in the treatment of wastewater but the sludge production becomes the biggest constraint in this treatment. Electrocoagulation is an alternative to conventional method because it has the same application but produce less sludge and requires simple equipment. Thus, combination of conventional coagulation and electrocoagulation can improve the efficiency of coagulation process in leachate treatment. This article is focusing on the efficiency of single and combined treatment as well as the improvement made by combined treatment. Based on review, the percentage reduction of current density and dose of coagulant was perceptible. As much 50% reduction of current density, duration of treatment, and dose of coagulant able to be obtained by using combined treatment. This combined treatment is able to reduce the cost and at the same time reduce the duration of treatment. Hence, the combined treatment offers an alternative technique for landfill leachate treatment on the removal of pollutants

Pharmaceuticals active compounds in the aquatic environment: a review

Pharmaceutical active substances utilised to treat human and animal diseases can launch into the environment through effluents from wastewater treatment plants and direct disposal of pharmaceutical compounds. Some of these compounds arrive in the environment as a parent compound or as active/inactive metabolites. Owing to their pharmacological action, their conceptions in the environment are significant, and thus this chapter reviews the understanding of the presence of pharmaceutical compounds in the environment

A review of wastewater treatment using natural material and its potential as aid and composite coagulant

The introduction of natural materials into the coagulation-flocculation process need to be practiced as common as possible. The previous literature indicated that utilization of natural material is actually worth to be developed and if possible, into the commercial one. However, the application of natural coagulants itself as the primary treatment is not sufficient, due to the rise in constraints which limited its performance. Emerging technologies and depth studies are actually helping these limited conditions to grow them as good as the performance of chemical coagulants. Alternatively, the natural-based coagulants are commonly used as coagulant aids alongside chemical coagulants, which have created a highlight in water research. This review covers the type of coagulants used in the coagulation-flocculation of wastewater treatment especially in the usage of natural-based coagulants. This review paper also outlines the future prospects of natural materials as aids and its potential as sustainable composite coagulants

Treatment of shallow groundwater quality for non-potable use: A case study in Parit Raja, Batu Pahat, Johor

Groundwater becomes an alternative water resource to meet up the demand of clean water in our country. Unfortunately, several contam-inants could present in groundwater make it unsafe for domestic used and drinking water purpose. Therefore, groundwater should be treated to acceptable level before it can be consumed for further use. The aim of this study was to improve the groundwater quality in terms of physical parameters and bring it within the acceptable level using simple and economical aeration and filtration methods. Gravel, ceramic and charcoal were used as filter materials. The removal efficiency was determined from the calculated percentage removal of the tested parameters. Based on the results, groundwater showed improvement in its physical quality with percentage removal of turbidity, BOD and COD at 92%, 73% and 79%, respectively. Parameter pH also showed good improvement from slightly acidic to neutral range. However, TDS gave different results. With the exception of TDS, all parameters comply with the Malaysia’s standard of raw and drink-ing water quality set by Ministry of Health

Settlement reduction of dredged marine soils (DMS) admixed with cement & waste granular materials (WGM): 1-D compressibility study

Dredged marine soils (DMS) are considered as geo-waste and commonly disposed far into the sea. Environmental impacts raised from dredging such as turbidity and disturbance of marine ecosystem had increased the social demand to reuse DMS in engineering application. Typically, DMS have low shear strength and low bearing capacity. Hence, the DMS could be strengthened up by soil solidification. In present study, waste granular materials (WGM) such as coal bottom ash (BA) and palm oil clinker (POC) were utilized as additional binder to cement. The DMS were solidified with 3 series of admixtures; namely cement and/or WGM. The factor that influenced the compressibility of the soil sample such as percentages of admixtures were considered. Proportioned samples of 10, 15 and 20 % of cement, and/or 50 and 150 % of WGM of dry weight of DMS were subjected to one-dimensional oedometer test. The test samples were cured for 7 days in room temperature. Results show that cement- and WGM-admixed DMS have reduced the soil’s compressibility considerably than the untreated sample. As expected, the cemented soil had significantly reduced the settlement better than WGM-admixed soil. Hence, homogeneous samples of 15C50BA and 10C100POC produced almost similar reduction of compressibility as sample 20C. Therefore, reusing WGM as partial replacement of cement in DMS could provide beneficial reuse of these materials

Application of Composite Coagulant In Removing Heavy Metals from Leachate via Coagulation-Flocculation Process

Leachate contains various particles which could contaminate ground water. Proper leachate control method must be selected for good water quality. One of them is by using coagulation-flocculation with improved material as composite coagulant (CC). This chapter aims to evaluate optimum CCs’ ratio and dosage, and leachates’ pH by CC made from tapioca peel powder (TPP) and polyaluminium chloride (PAC) through the heavy metals reduction in copper (Cu), zinc (Zn), and chromium (Cr) from Simpang Renggam landfill. Tapioca peel from industry was cleaned and mixed with distilled water, filtered, and left under the sun to dry up. By doing jar test of ten ratios of CC and eight dosages, optimum ratio and dosage of CC by heavy metals reduction was determined. The initial and final heavy metal concentrations were measured by ICP-MS. The highest percentage removal (2:9, 3500 mg/L) in terms of Cu, Zn, and Cr was 51.14, 79.63, and 79.23, respectively. Compared to the ratio 1:10, at optimum conditions (4000 mg/L), was 40.51, 83.43, and 91.16 removals, respectively. Ratio 2:9 was chosen because contained more TPP that could save cost and reduce the use of chemical coagulant. It could be determined that the optimum ratio and dosage of CC was 2:9, 3500mg/L, and the optimum sample pH 6 with removals of Cu, Zn, Cr was 55.30, 29.80, 74.98, respectively

Removal of Suspended Solid, Colour and Ammoniacal-Nitrogen from Leachate Using Aerated Electrochemical Coagulation (AEC) Under The Influence Factors of pH and Electrolysis Duration

The leachate produced by the decomposition of waste in landfills contains toxic substances that pollute the environment and cause health concerns which proper leachate treatment is essential before leachate is directly discharge into the environment. The most important factors to be considered when adopting a leachate treatment are effluent removal performance and the ability of treated effluent to satisfy the standard limit discharge. This study investigates the optimum condition of Aerated Electrochemical Coagulation (AEC), a mix of physical and chemical treatments in removing suspended solid, colour and ammonia from leachate under the influence factors of pH and electrolysis duration. Stabilised leachate from Simpang Renggam Landfill was used as samples for this study. From the data analysis, the highest removal effectiveness was achieved at 10 minutes of electrolysis duration and pH 5 for removal of suspended solid, colour and ammonia with 93%, 93%, and 40%, respectively. Based on the data, integration of the aeration method into electrochemical coagulation in leachate treatment has shown enhancement of the removal efficiency of suspended solid, colour and ammonia. However, only suspended solid satisfy the standard leachate discharge

Removal of Suspended Solid, Colour and Ammoniacal-Nitrogen from Leachate Using Aerated Electrochemical Coagulation (AEC) Under The Influence Factors of pH and Electrolysis Duration

The leachate produced by the decomposition of waste in landfills contains toxic substances that pollute the environment and cause health concerns which proper leachate treatment is essential before leachate is directly discharge into the environment. The most important factors to be considered when adopting a leachate treatment are effluent removal performance and the ability of treated effluent to satisfy the standard limit discharge. This study investigates the optimum condition of Aerated Electrochemical Coagulation (AEC), a mix of physical and chemical treatments in removing suspended solid, colour and ammonia from leachate under the influence factors of pH and electrolysis duration. Stabilised leachate from Simpang Renggam Landfill was used as samples for this study. From the data analysis, the highest removal effectiveness was achieved at 10 minutes of electrolysis duration and pH 5 for removal of suspended solid, colour and ammonia with 93%, 93%, and 40%, respectively. Based on the data, integration of the aeration method into electrochemical coagulation in leachate treatment has shown enhancement of the removal efficiency of suspended solid, colour and ammonia. However, only suspended solid satisfy the standard leachate discharge

Experimental Evaluation on Physical and Mechanical Properties of Concrete Containing Green Mussel Shell (Perna viridis) Powder as an Admixture

Mussel shell is a type of waste that is generated abundantly. However, the presence of chemical components such as calcium (CaCO3) in mussel shells has shown its potential as filler materials in concrete designing. Therefore, this paper presents the experimental result for the physical and mechanical properties of concrete containing 1%, 2%, 3% and 4% Mussel Shell Powder (MSP) as additional material under 2.73% sodium chloride solution. The MSP has been cleaned, grinded and sieved 75μm sizes in order to obtain its final product. Compressive strength, split tensile, and capillary water absorption were determined. Statistical analysis was performed to investigate the correlation and level of significance using IBM SPSS in determining the optimal mix design for modified concrete. The performance of MSP concrete and control specimens are the main factor that been observed in this study. The increment percentages of MSP in concrete had led to reduce on its mechanical strength, however improved in its absorption rates. According to statistical analysis, it shows that low MSP percentages giving a significant value for compressive strength and very strong correlation coefficient compared to control specimens, thus it indicated minimum MSP percentages are more potential in improving concrete physical and mechanical performance