Polyaniline (PANI) is one of the unique conducting polymers due to tunable conductivity, acid-base chemistry and optical properties. In this study, commercial PANI was used to prepare PANI/shell composites to enhance the sensitivity of PANI in ammonia (NH3) gas detection. Three types of waste shells were utilized to incorporate into the PANI matrix such as egg shells (ES), crab shells (CS) and mussel shells (MS). The characterizations were done by Fourier transform infrared (FTIR) and ultraviolet-visible (UV-Vis) spectrophotometer. FTIR spectra confirmed the presence of CaCO3 in the PANI/shell composites’ backbone. Whereas, UV-Vis spectra further confirmed the PANI/shell composites were in the doped state by exhibiting a characteristic peak at ~790-820 nm. Sensor performance of commercial PANI and PANI/shell composite films were studied in terms of sensor measurement and sensor performances (selectivity, reusability and long-term stability). The sensor performances of commercial PANI, PANI/ES and PANI/CS exhibited correlation coefficient of >0.95. In addition, commercial PANI and PANI/CS films exhibited good selectivity for NH3 gas detection in the presence of interfering gases. In conclusion, PANI/shell composites were successfully prepared for NH3 gas detection and PANI/CS exhibited the highest sensitivity compared to other films.

Cat manure (CM) possesses high level of nutrients for growing food crop. However, animal manure may contain toxic elements that may contaminate food crop. Spent coffee ground (SCG) may be used to reduce mobility of heavy metals and reduce crop uptake. In this study, SCG was composted with CM for 31 days to produce a co-compost (SCG-CM) for growing spinach ( Spinacia oleracea ). The growth rate of spinach was assessed until its maturity, and the metal uptake of spinach shoot was determined thereafter using inductively coupled plasma-optical emission spectroscopy (ICP-OES). The effect of soil treatment with SCG-CM on the height and elemental composition of spinach were compared with that of chicken manure compost (CMC). The prepared composts were primarily organic matter (72.9–81.4 % w/w) with the rest are ash (13.3–23.4 % w/w) and moisture (1.2–2.6 % w/w). Zinc content in SCG-CM (1261 ± 0.1 mg/kg) is significantly higher than that of soil and CMC (p < 0.05) and has exceeded the maximum permissible limit set by European Union Standard (2002) and the Malaysian Compost Quality Standard and Guidelines (2000). Matured spinach reached maximum plant height after 33 days. The amendment of SCG-CM significantly increased the height of spinach (32 ± 6 cm) compared to that of CMC (13 ± 1 cm) (p < 0.05). However, contents of Zn, Cu, Pb and Cd were not increased for spinach grown in the SCG-CM-amended soil, and the level of those elements are below permissible limit set by the Malaysian Food Act 1983 and Food Regulations 1985. This study shows that SCG-CM is effective in improving yield without causing accumulation of toxic trace elements in spinach.

In this study, thedye treatment which is methylene blue ascertained with the activated carbon that prepared from the tamarind seed (Tamarindusindica). The conditions used to prepare activated carbon, using phosphoric acid as an activating agent at temperature 500 conditions may be attributed to enhance the surface area and pores development of TSC.Single point BET surface area (S and FESEM analysis showed that the pores development and formation were mostly in circle and oval pattern. The best conditions for TSC sample to adsorb MB effectively were at 50 mL of MB with concentration 120 ppm at temperature, 323 K by u maximum adsorption capacity for MB dye solution was 102.77 mg g In this study, thedye treatment which is methylene blue (MB) as water pollutants the activated carbon that prepared from the tamarind seed ). The conditions used to prepare activated carbon, (TSC) were activat using phosphoric acid as an activating agent at temperature 500 o C for four hours. These conditions may be attributed to enhance the surface area and pores development of TSC.Single point BET surface area (S BET ) analysis gave the surface area of TSC was and FESEM analysis showed that the pores development and formation were mostly in circle and oval pattern. The best conditions for TSC sample to adsorb MB effectively were at 50 mL of MB with concentration 120 ppm at temperature, 323 K by using 0.04 g of TSC. The maximum adsorption capacity for MB dye solution was 102.77 mg g -1 .; methylene blue; adsorption; phosphoric acid.

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Biochar has an alkaline and porous structure that could be a potential material for recycling phosphorous (P) from urine. Sawdust (SD) was pyrolyzed to produce sawdust biochar (SDB), and then impregnated with magnesium (Mg) to produce Mg-impregnated biochar (SDBM). Artificial human urine (AHU) solution was used for a batch sorption study, and various sorption parameters (i.e., sorbent/solution ratio, pH of AHU, and initial total P concentration of AHU) were optimized. The concentration of total P was measured using an inductively coupled plasma-optical emission spectroscopy (ICP-OES). The surface morphology and elemental analysis for SDB, SDBM and the struvite-loaded SDBM (SMSDB) were investigated using scanning electron spectroscopy-energy dispersive x-ray spectroscopy (SEM-EDX). The total P sorption capacity for SDBM (32755 mg/g) was higher than that of SDB (7782 mg/g) and SD (10682 mg/g). The optimum total P removal for SDBM (21.2%) was achieved at a sorbent/solution ratio of 0.06g/L at pH 9. Sorption of total P may have occurred on the heterogeneous surface of SDBM. The presence of struvite crystals indicates that phosphate was adsorbed and then precipitated on the surface of SDBM.

Surfactants also known as surface-active agents are one of the water pollutants that can lead to the deterioration of the environment. In this study, activated carbon was prepared from date seeds (DAC) by using phosphoric acid as an activating agent. The activation process was carried out at 500 °C for two hours. DAC was characterized by Fourier-Transformed Infrared Spectrometer (FTIR), Field Emission Scanning Electron Microscopy (FESEM), Energy-Dispersive X-Ray Spectroscopy (EDX) and Nitrogen Adsorption at 77 K. The BET surface area of DAC was 1187 m 2 /g. The adsorption capacities of surfactants (CTAB and TX-100) were determined. This study showed that the adsorption capacity of CTAB (23.0724 mg/g) onto DAC was greater than TX-100 (11.3868 mg/g). The adsorption process between both surfactants onto DAC was done by physisorption through electrostatic forces. Thus, this study showed that the date seeds have a greater tendency to be microporous activated carbon and an adsorbent for surfactants recovery.Keywords: activated carbon, phosphoric acid, date seed Abstrak Bahan aktif permukaan juga dikenali sebagai surfaktan adalah salah satu bahan pencemar air yang boleh membawa kepada kemerosotan alam sekitar. Dalam kajian ini, karbon teraktif telah disediakan daripada biji kurma (DAC) dengan menggunakan asid fosforik sebagai ejen pengaktifan. Proses pengaktifan telah dilakukan pada suhu 500 °C selama dua jam. Karbon teraktif (DAC) telah dicirikan oleh Spektroskopi Inframerah Transformasi Fourier (FTIR), Mikroskopi Medan Pancaran Imbasan Elektron (FESEM), Sebaran Tenaga Sinar-X (EDX) dan penjerapan gas nitrogen pada suhu 77 K. Luas permukaan BET kawasan DAC adalah 1187 m 2 /g. Kapasiti penjerapan surfaktan (CTAB dan TX-100) telah dikaji. Kajian ini menunjukkan bahawa kapasiti penjerapan CTAB (23.0724 mg/g) pada DAC adalah lebih tinggi daripada TX-100 (11.3868 mg/g). Proses penjerapan antara bagi kedua-dua surfaktan DAC adalah secara penjerapan fizikal melalui daya elektrostatik. Oleh itu, kajian ini menunjukkan bahawa biji kurma mempunyai kecenderungan yang lebih besar sebagai karbon teraktif berliang mikro dan bahan penjerap yang baik untuk pemulihan surfaktan.

Constructed wetlands possess tremendous nature values, namely instrumental and intrinsic values. Constructed wetlands also store and capture carbon which help to mitigate climate change in sustaining our earth system. Hence, sound management of constructed wetlands must consider its importance as essential assets that increase their resilience in mitigation and adaptation strategies towards adverse effects of climate change. To examine the vital value of constructed wetlands, this study attempts to evaluate the content validity of the developed Intrinsic-Instrument Assessment (IIA) tool for assessing the nature values of constructed wetlands in the context of climate change. A methodological study was conducted to evaluate the content validity of the IIA tool in two-phases. First, a comprehensive literature review was conducted at the development phase to identify the construct and dimension, generate items and instrument formation. In the second phase (evaluation), a committee of six experts performed the content validity evaluation, and the content validity index was implemented for content validity quantification. Finally, the researcher conducted a discussion between the team members to finalise the items of the IIA tool. The first version of the IIA tool identified three domains (instrumental, objective and intrinsic values) with 36 items. The item content validity index (I-CVI) ranges from 0.833 to 1. The overall content validity index using the average approach, the scale content validity index (S-CVI/Ave) is 0.97. Thus, the IIA tool was evaluated with highly relevant and excellent content validity. Researchers generated 17 additional items in the IIA version 2.0 after considering experts' feedback. Still, after the second evaluation by researchers, the final version of the IIA tool consists of 42 items. This paper contributes to the body of knowledge by performing the systematic process of the essential steps to verify the developed instrument's reliability and validity, especially in the field of socio-ecology. This study provides comprehensive information and example as guidance for evaluating content validity for a new instrument scale. Also, it helps to bring insight into constructed wetlands' vital nature values as the nature solution in mitigating and adapting climate change to advocate the sustainable development of constructed wetlands ecosystems.