Chapter 252

The centrifuge in the criminal investigation laboratory made a "humming" sound. Old Zheng took off his gloves, and the incandescent light cast a blue-gray shadow under his eyelids.

"The complexation reaction simulation results are out." He tapped the keyboard, and the Longhu 3D model rotated on the screen, with the red area spreading from the floodgate to the surroundings, "At 2:07 AM, the water temperature happened to rise to 15.2 degrees."

Gao Ye stared at the fluctuating curve and said: "After the cobalt tetraphenylporphyrin solution in the titanium alloy tank was released, the moment it came into contact with the acidic wastewater..." He suddenly stopped, and the molecular structure on the screen was reorganizing crazily.

"Produced a Fenton-like reaction." Ye Lin pulled up the spectral analysis chart, "The hydroxyl radical concentration soared 200 times within 30 seconds. This is equivalent to turning the lake water into diluted concentrated sulfuric acid."

Gu Changzheng's index finger unconsciously rubbed the autopsy report, and the diatoms in Chen Guodong's alveoli suddenly swam in his memory. The shell patterns of those single-celled organisms were surprisingly similar to the burn carbonization patterns on the deceased's palms.

Zhou Shichang's crocodile leather briefcase was placed on the interrogation table, and the gold-plated cufflinks collided with the stainless steel shackles to make a fine sound. "My lawyer is on the way." He smoothed the wrinkles on the front of his suit, "As for that German-made container, it's just wastewater sampling equipment."

Luo Fei slapped the cyanide test report left by the weather station on the desktop: "Do I need to remind you of Professor Chen's report on your factory's illegal discharge of cyanide-containing wastewater ten years ago?" The projector lit up, and the 2015 Environmental Award ceremony video was placed side by side with the 2005 pollution accident report. Chen Guodong's suit changed from navy blue to gray-blue, but his eyes were equally sharp.

"Just an old pipeline leak." Zhou Shichang's thumb spun on the platinum tail ring, "Besides, didn't Professor Chen help us improve the treatment process later?" He suddenly leaned forward, and the shadow swallowed half of the table, "The new water treatment agent he developed can increase the decomposition rate of cyanide to 99.9%."

Old Zheng behind the one-way glass gripped his thermos cup tightly, and the goji berries tumbled up and down in the boiling water.

The sealed box sent by the physical evidence department was cold, and the remaining materials from Chen Guodong's laboratory were spread out under the antibacterial lamp. Ye Lin swept over the charred paper pages with a soft brush and suddenly whispered: "There are indentations here!" The moment the spectral imager started, Luo Fei saw the deceased's handwriting before his death emerge in the ashes:

【When the complexing agent concentration > 0.3mol/L, the aluminum-EDTA complex appears abnormal phase transition】

Old Zheng grabbed a magnifying glass, and the ink diffusion pattern at the edge of the indentation made his temples throb. "This was written with a German Schmidt needle pen, and the ink contains potassium ferricyanide." He turned to look at Gu Changzheng, "Do you remember the ink stains on the deceased's right tiger's mouth?"

The surveillance video of the forensic room was adjusted to 3x speed, and the screen froze before Chen Guodong's body was encoffined—there were indeed blue-black spots on the right tiger's mouth, which were mistaken for livor mortis at the time.

The hazardous waste warehouse of the Huasheng Chemical Plant was shrouded in searchlights, and Xiao Sun operated the robotic arm with a radiation-proof mask. When the storage tank numbered B-7 was lifted, the brown scabs stuck to the bottom of the tank fell off with a rustle. Gao Ye froze the sample with a liquid nitrogen gun, and purple smoke instantly rose in the crystallization dish.

"Mixed residue of ferric chloride and sodium cyanide." Old Zheng's detector sounded an alarm, "This old-fashioned cyanide removal process should have been eliminated by Professor Chen's new technology long ago."

Gu Changzheng's leather shoes crushed the crystals on the ground, and the creaking sound reminded him of the binding thread of the case file. On page 47 of the pollution accident file ten years ago, the copy of the guarantee letter handwritten by Zhou Shichang had turned yellow, and the exclamation mark at the end of the promise sentence was like a rusty dagger.

"Check the complexing agent purchase records for 2005." He suddenly pressed his Bluetooth headset, "Track the flow of EDTA disodium salt."

The data center at midnight was full of hard drive humming. Xiao Sun cracked the encrypted financial subsystem. The blue light of the screen reflected his oily nose tip: "In October 2005, two months after the pollution accident, Huasheng suddenly purchased five tons of EDTA disodium salt." The mouse wheel scrolled down, "But the wastewater treatment volume in the same year decreased by 60% year-on-year."

Ye Lin projected the molecular model onto the panoramic screen, and the complexation bond between aluminum ions and EDTA was breaking. She pulled up the Longhu sediment test data, "Excessive complexing agent will reverse the reaction in an acidic environment, just like pouring liquid nitrogen into a volcano."

Luo Fei suddenly pulled away the cover on the whiteboard, and the equation from Chen Guodong's laboratory was completely presented. In a corner that had been burned, half of the reaction condition annotation remained: temperature > 35℃, pH < 2.

"Human oral temperature 36℃." Gu Changzheng's voice was like a tightened steel wire, "That box of chocolates Zhou Shichang sent."

The shadowless lamp in the forensic autopsy room was adjusted to the brightest, and Old Zheng put the deceased's gastric mucosa section into the electron microscope. In the dark green field of vision, the holes on the cell membrane were arranged in a strange pattern, like the lunar surface hit by a meteor shower.

"This is chromosome breakage caused by α-rays!" He suddenly raised his head, and the scalpel clattered onto the tiles, "Immediately test the deceased's bone strontium-90 content!"

The radiation detection room at 4:00 AM sounded an alarm, and the Geiger counter swung wildly above Chen Guodong's rib cage. Xiao Sun stared at the reading, his face turning pale: "Radioactive activity exceeded the standard by 170 times, equivalent to..."

"Equivalent to lying in an X-ray machine for half a month." Old Zheng pulled open the collar of his protective suit, "But there is no report of radioactive material exceeding the standard in Longhu water quality."

Gu Changzheng grabbed the white powder sample left by the weather station, and the gamma spectrometer screamed and drew the characteristic peak of thorium-232.

Zhou Shichang's platinum tail ring glowed coldly in the evidence bag. Gu Changzheng used proton-induced X-ray scanning on the surface layer, and the hidden wear patterns gradually took shape—that was a micro-radioactive source sign.

"At the 2014 Hannover Chemical Exhibition, Company M was punished for illegally carrying radioactive sources." Gu Changzheng pushed the penalty notice under the interrogation light, "As a technical consultant at that time, you assisted in the transfer of thorium-based catalysts."

Zhou Shichang's Adam's apple moved up and down, and cold sweat slid along his temples into the collar of his Armani shirt. Luo Fei behind the one-way glass suddenly raised the evidence bag, and the ink remaining in Chen Guodong's laboratory was glowing with ghostly blue fluorescence.

"Potassium ferricyanide reacts with thorium-232 to trigger the Auger effect." Old Zheng's voice came from the loudspeaker, "You mixed radioactive sources into the ink box commonly used by Professor Chen, letting him suffer from chronic poisoning while writing equations."

The interrogation room ceiling light flickered suddenly, and Zhou Shichang's shadow twisted into a clawing monster on the wall. A dull explosion came from the direction of the chemical plant in the distance, and the Longhu water surface glowed with sickly phosphorescence.